rfc2518.txt   draft-ietf-webdav-rfc2518bis-latest.txt 
Network Working Group Y. Goland WebDAV Working Group L. Dusseault, Ed.
Request for Comments: 2518 Microsoft Internet-Draft CommerceNet
Category: Standards Track E. Whitehead Obsoletes: 2518 (if approved) February 15, 2007
UC Irvine Intended status: Standards Track
A. Faizi Expires: August 19, 2007
Netscape
S. Carter
D. Jensen
Novell
February 1999
HTTP Extensions for Distributed Authoring -- WEBDAV HTTP Extensions for Distributed Authoring - WebDAV
draft-ietf-webdav-rfc2518bis-18
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Abstract Abstract
This document specifies a set of methods, headers, and content-types WebDAV consists of a set of methods, headers, and content-types
ancillary to HTTP/1.1 for the management of resource properties, ancillary to HTTP/1.1 for the management of resource properties,
creation and management of resource collections, namespace creation and management of resource collections, URL namespace
manipulation, and resource locking (collision avoidance). manipulation, and resource locking (collision avoidance).
Table of Contents RFC2518 was published in February 1999, and this specification makes
minor revisions mostly due to interoperability experience.
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 6 Table of Contents
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 7
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Data Model for Resource Properties . . . . . . . . . . . . . 8
4.1. The Resource Property Model . . . . . . . . . . . . . . 8
4.2. Existing Metadata Proposals . . . . . . . . . . . . . . 9
4.3. Properties and HTTP Headers . . . . . . . . . . . . . . 9
4.4. Property Values . . . . . . . . . . . . . . . . . . . . 10
4.5. Property Names . . . . . . . . . . . . . . . . . . . . . 10
4.6. Media Independent Links . . . . . . . . . . . . . . . . 11
5. Collections of Web Resources . . . . . . . . . . . . . . . . 11
5.1. HTTP URL Namespace Model . . . . . . . . . . . . . . . . 11
5.2. Collection Resources . . . . . . . . . . . . . . . . . . 11
5.3. Creation and Retrieval of Collection Resources . . . . . 13
5.4. Source Resources and Output Resources . . . . . . . . . 13
6. Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1. Exclusive Vs. Shared Locks . . . . . . . . . . . . . . . 15
6.2. Required Support . . . . . . . . . . . . . . . . . . . . 16
6.3. Lock Tokens . . . . . . . . . . . . . . . . . . . . . . 16
6.4. opaquelocktoken Lock Token URI Scheme . . . . . . . . . 16
6.4.1. Node Field Generation Without the IEEE 802 Address . 17
6.5. Lock Capability Discovery . . . . . . . . . . . . . . . 19
6.6. Active Lock Discovery . . . . . . . . . . . . . . . . . 19
6.7. Usage Considerations . . . . . . . . . . . . . . . . . . 20
7. Write Lock . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.1. Methods Restricted by Write Locks . . . . . . . . . . . 21
7.2. Write Locks and Lock Tokens . . . . . . . . . . . . . . 21
7.3. Write Locks and Properties . . . . . . . . . . . . . . . 21
7.4. Write Locks and Null Resources . . . . . . . . . . . . . 21
7.5. Write Locks and Collections . . . . . . . . . . . . . . 22
7.6. Write Locks and the If Request Header . . . . . . . . . 22
7.6.1. Example - Write Lock . . . . . . . . . . . . . . . . 23
7.7. Write Locks and COPY/MOVE . . . . . . . . . . . . . . . 23
7.8. Refreshing Write Locks . . . . . . . . . . . . . . . . . 24
8. HTTP Methods for Distributed Authoring . . . . . . . . . . . 24
8.1. PROPFIND . . . . . . . . . . . . . . . . . . . . . . . . 24
8.1.1. Example - Retrieving Named Properties . . . . . . . 26
8.1.2. Example - Using allprop to Retrieve All Properties . 28
8.1.3. Example - Using propname to Retrieve all Property
Names . . . . . . . . . . . . . . . . . . . . . . . 31
8.2. PROPPATCH . . . . . . . . . . . . . . . . . . . . . . . 33
8.2.1. Status Codes for use with 207 (Multi-Status) . . . . 33
8.2.2. Example - PROPPATCH . . . . . . . . . . . . . . . . 34
8.3. MKCOL Method . . . . . . . . . . . . . . . . . . . . . . 35
8.3.1. Request . . . . . . . . . . . . . . . . . . . . . . 35
8.3.2. Status Codes . . . . . . . . . . . . . . . . . . . . 36
8.3.3. Example - MKCOL . . . . . . . . . . . . . . . . . . 36
8.4. GET, HEAD for Collections . . . . . . . . . . . . . . . 37
8.5. POST for Collections . . . . . . . . . . . . . . . . . . 37
8.6. DELETE . . . . . . . . . . . . . . . . . . . . . . . . . 37
8.6.1. DELETE for Non-Collection Resources . . . . . . . . 37
8.6.2. DELETE for Collections . . . . . . . . . . . . . . . 37
8.7. PUT . . . . . . . . . . . . . . . . . . . . . . . . . . 39
8.7.1. PUT for Non-Collection Resources . . . . . . . . . . 39
8.7.2. PUT for Collections . . . . . . . . . . . . . . . . 39
8.8. COPY Method . . . . . . . . . . . . . . . . . . . . . . 39
8.8.1. COPY for HTTP/1.1 resources . . . . . . . . . . . . 40
8.8.2. COPY for Properties . . . . . . . . . . . . . . . . 40
8.8.3. COPY for Collections . . . . . . . . . . . . . . . . 40
8.8.4. COPY and the Overwrite Header . . . . . . . . . . . 42
8.8.5. Status Codes . . . . . . . . . . . . . . . . . . . . 42
8.8.6. Example - COPY with Overwrite . . . . . . . . . . . 42
8.8.7. Example - COPY with No Overwrite . . . . . . . . . . 43
8.8.8. Example - COPY of a Collection . . . . . . . . . . . 43
8.9. MOVE Method . . . . . . . . . . . . . . . . . . . . . . 44
8.9.1. MOVE for Properties . . . . . . . . . . . . . . . . 45
8.9.2. MOVE for Collections . . . . . . . . . . . . . . . . 45
8.9.3. MOVE and the Overwrite Header . . . . . . . . . . . 46
8.9.4. Status Codes . . . . . . . . . . . . . . . . . . . . 46
8.9.5. Example - MOVE of a Non-Collection . . . . . . . . . 46
8.9.6. Example - MOVE of a Collection . . . . . . . . . . . 47
8.10. LOCK Method . . . . . . . . . . . . . . . . . . . . . . 48
8.10.1. Operation . . . . . . . . . . . . . . . . . . . . . 48
8.10.2. The Effect of Locks on Properties and Collections . 48
8.10.3. Locking Replicated Resources . . . . . . . . . . . . 49
8.10.4. Depth and Locking . . . . . . . . . . . . . . . . . 49
8.10.5. Interaction with other Methods . . . . . . . . . . . 49
8.10.6. Lock Compatibility Table . . . . . . . . . . . . . . 50
8.10.7. Status Codes . . . . . . . . . . . . . . . . . . . . 50
8.10.8. Example - Simple Lock Request . . . . . . . . . . . 51
8.10.9. Example - Refreshing a Write Lock . . . . . . . . . 53
8.10.10. Example - Multi-Resource Lock Request . . . . . . . 54
8.11. UNLOCK Method . . . . . . . . . . . . . . . . . . . . . 55
8.11.1. Example - UNLOCK . . . . . . . . . . . . . . . . . . 55
9. HTTP Headers for Distributed Authoring . . . . . . . . . . . 56
9.1. DAV Header . . . . . . . . . . . . . . . . . . . . . . . 56
9.2. Depth Header . . . . . . . . . . . . . . . . . . . . . . 56
9.3. Destination Header . . . . . . . . . . . . . . . . . . . 57
9.4. If Header . . . . . . . . . . . . . . . . . . . . . . . 57
9.4.1. No-tag-list Production . . . . . . . . . . . . . . . 58
9.4.2. Tagged-list Production . . . . . . . . . . . . . . . 58
9.4.3. not Production . . . . . . . . . . . . . . . . . . . 59
9.4.4. Matching Function . . . . . . . . . . . . . . . . . 60
9.4.5. If Header and Non-DAV Compliant Proxies . . . . . . 60
9.5. Lock-Token Header . . . . . . . . . . . . . . . . . . . 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 8
9.6. Overwrite Header . . . . . . . . . . . . . . . . . . . . 60 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 10
9.7. Status-URI Response Header . . . . . . . . . . . . . . . 61 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.8. Timeout Request Header . . . . . . . . . . . . . . . . . 61 4. Data Model for Resource Properties . . . . . . . . . . . . . 13
10. Status Code Extensions to HTTP/1.1 . . . . . . . . . . . . . 62 4.1. The Resource Property Model . . . . . . . . . . . . . . 13
10.1. 102 Processing . . . . . . . . . . . . . . . . . . . . . 62 4.2. Properties and HTTP Headers . . . . . . . . . . . . . . 13
10.2. 207 Multi-Status . . . . . . . . . . . . . . . . . . . . 63 4.3. Property Values . . . . . . . . . . . . . . . . . . . . 13
10.3. 422 Unprocessable Entity . . . . . . . . . . . . . . . . 63 4.3.1. Example - Property with Mixed Content . . . . . . . 15
10.4. 423 Locked . . . . . . . . . . . . . . . . . . . . . . . 63 4.4. Property Names . . . . . . . . . . . . . . . . . . . . . 17
10.5. 424 Failed Dependency . . . . . . . . . . . . . . . . . 63 4.5. Source Resources and Output Resources . . . . . . . . . 17
10.6. 507 Insufficient Storage . . . . . . . . . . . . . . . . 63 5. Collections of Web Resources . . . . . . . . . . . . . . . . 18
11. Multi-Status Response . . . . . . . . . . . . . . . . . . . . 64 5.1. HTTP URL Namespace Model . . . . . . . . . . . . . . . . 18
12. XML Element Definitions . . . . . . . . . . . . . . . . . . . 64 5.2. Collection Resources . . . . . . . . . . . . . . . . . . 18
12.1. activelock XML Element . . . . . . . . . . . . . . . . . 64 6. Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
12.1.1. depth XML Element . . . . . . . . . . . . . . . . . 64 6.1. Lock Model . . . . . . . . . . . . . . . . . . . . . . . 21
12.1.2. locktoken XML Element . . . . . . . . . . . . . . . 65 6.2. Exclusive Vs. Shared Locks . . . . . . . . . . . . . . . 22
12.1.3. timeout XML Element . . . . . . . . . . . . . . . . 65 6.3. Required Support . . . . . . . . . . . . . . . . . . . . 23
12.2. collection XML Element . . . . . . . . . . . . . . . . . 65 6.4. Lock Creator and Privileges . . . . . . . . . . . . . . 23
12.3. href XML Element . . . . . . . . . . . . . . . . . . . . 65 6.5. Lock Tokens . . . . . . . . . . . . . . . . . . . . . . 24
12.4. link XML Element . . . . . . . . . . . . . . . . . . . . 66 6.6. Lock Timeout . . . . . . . . . . . . . . . . . . . . . . 25
12.4.1. dst XML Element . . . . . . . . . . . . . . . . . . 66 6.7. Lock Capability Discovery . . . . . . . . . . . . . . . 25
12.4.2. src XML Element . . . . . . . . . . . . . . . . . . 66 6.8. Active Lock Discovery . . . . . . . . . . . . . . . . . 26
12.5. lockentry XML Element . . . . . . . . . . . . . . . . . 67 7. Write Lock . . . . . . . . . . . . . . . . . . . . . . . . . 27
12.6. lockinfo XML Element . . . . . . . . . . . . . . . . . . 67 7.1. Write Locks and Properties . . . . . . . . . . . . . . . 27
12.7. lockscope XML Element . . . . . . . . . . . . . . . . . 67 7.2. Avoiding Lost Updates . . . . . . . . . . . . . . . . . 28
12.7.1. exclusive XML Element . . . . . . . . . . . . . . . 68 7.3. Write Locks and Unmapped URLs . . . . . . . . . . . . . 29
12.7.2. shared XML Element . . . . . . . . . . . . . . . . . 68 7.4. Write Locks and Collections . . . . . . . . . . . . . . 30
12.8. locktype XML Element . . . . . . . . . . . . . . . . . . 68 7.5. Write Locks and the If Request Header . . . . . . . . . 31
12.8.1. write XML Element . . . . . . . . . . . . . . . . . 68 7.5.1. Example - Write Lock and COPY . . . . . . . . . . . 32
12.9. multistatus XML Element . . . . . . . . . . . . . . . . 69 7.5.2. Example - Deleting a Member of a Locked Collection . 32
12.9.1. response XML Element . . . . . . . . . . . . . . . . 69 7.6. Write Locks and COPY/MOVE . . . . . . . . . . . . . . . 33
12.9.2. responsedescription XML Element . . . . . . . . . . 70 7.7. Refreshing Write Locks . . . . . . . . . . . . . . . . . 34
12.10. owner XML Element . . . . . . . . . . . . . . . . . . . 70 8. General Request and Response Handling . . . . . . . . . . . . 35
12.11. prop XML element . . . . . . . . . . . . . . . . . . . . 71 8.1. Precedence in Error Handling . . . . . . . . . . . . . . 35
12.12. propertybehavior XML element . . . . . . . . . . . . . . 71 8.2. Use of XML . . . . . . . . . . . . . . . . . . . . . . . 35
12.12.1. keepalive XML element . . . . . . . . . . . . . . . 71 8.3. URL Handling . . . . . . . . . . . . . . . . . . . . . . 36
12.12.2. omit XML element . . . . . . . . . . . . . . . . . . 72 8.3.1. Example - Correct URL Handling . . . . . . . . . . . 36
12.13. propertyupdate XML element . . . . . . . . . . . . . . . 72 8.4. Required Bodies in Requests . . . . . . . . . . . . . . 37
12.13.1. remove XML element . . . . . . . . . . . . . . . . . 73 8.5. HTTP Headers for use in WebDAV . . . . . . . . . . . . . 37
12.13.2. set XML element . . . . . . . . . . . . . . . . . . 73 8.6. ETag . . . . . . . . . . . . . . . . . . . . . . . . . . 37
12.14. propfind XML Element . . . . . . . . . . . . . . . . . . 74 8.7. Including Error Response Bodies . . . . . . . . . . . . 38
12.14.1. allprop XML Element . . . . . . . . . . . . . . . . 74 8.8. Impact of Namespace Operations on Cache Validators . . . 38
12.14.2. propname XML Element . . . . . . . . . . . . . . . . 74 9. HTTP Methods for Distributed Authoring . . . . . . . . . . . 40
13. DAV Properties . . . . . . . . . . . . . . . . . . . . . . . 74 9.1. PROPFIND Method . . . . . . . . . . . . . . . . . . . . 40
13.1. creationdate Property . . . . . . . . . . . . . . . . . 75 9.1.1. PROPFIND Status Codes . . . . . . . . . . . . . . . 41
13.2. displayname Property . . . . . . . . . . . . . . . . . . 75 9.1.2. Status Codes for Use in 'propstat' Element . . . . . 42
13.3. getcontentlanguage Property . . . . . . . . . . . . . . 75 9.1.3. Example - Retrieving Named Properties . . . . . . . 42
13.4. getcontentlength Property . . . . . . . . . . . . . . . 76 9.1.4. Example - Using 'propname' to Retrieve All
13.5. getcontenttype Property . . . . . . . . . . . . . . . . 76 Property Names . . . . . . . . . . . . . . . . . . . 44
13.6. getetag Property . . . . . . . . . . . . . . . . . . . . 76 9.1.5. Example - Using So-called 'allprop' . . . . . . . . 46
13.7. getlastmodified Property . . . . . . . . . . . . . . . . 77 9.1.6. Example - Using 'allprop' with 'include' . . . . . . 49
13.8. lockdiscovery Property . . . . . . . . . . . . . . . . . 77 9.2. PROPPATCH Method . . . . . . . . . . . . . . . . . . . . 49
13.8.1. Example - Retrieving the lockdiscovery Property . . 78 9.2.1. Status Codes for Use in 'propstat' Element . . . . . 50
13.9. resourcetype Property . . . . . . . . . . . . . . . . . 79 9.2.2. Example - PROPPATCH . . . . . . . . . . . . . . . . 51
13.10. source Property . . . . . . . . . . . . . . . . . . . . 80 9.3. MKCOL Method . . . . . . . . . . . . . . . . . . . . . . 52
13.10.1. Example - A source Property . . . . . . . . . . . . 80 9.3.1. MKCOL Status Codes . . . . . . . . . . . . . . . . . 53
13.11. supportedlock Property . . . . . . . . . . . . . . . . . 81 9.3.2. Example - MKCOL . . . . . . . . . . . . . . . . . . 53
13.11.1. Example - Retrieving the supportedlock Property . . 81 9.4. GET, HEAD for Collections . . . . . . . . . . . . . . . 54
14. Instructions for Processing XML in DAV . . . . . . . . . . . 82 9.5. POST for Collections . . . . . . . . . . . . . . . . . . 54
15. DAV Compliance Classes . . . . . . . . . . . . . . . . . . . 83 9.6. DELETE Requirements . . . . . . . . . . . . . . . . . . 54
15.1. Class 1 . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6.1. DELETE for Collections . . . . . . . . . . . . . . . 55
15.2. Class 2 . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6.2. Example - DELETE . . . . . . . . . . . . . . . . . . 55
16. Internationalization Considerations . . . . . . . . . . . . . 83 9.7. PUT Requirements . . . . . . . . . . . . . . . . . . . . 56
17. Security Considerations . . . . . . . . . . . . . . . . . . . 85 9.7.1. PUT for Non-Collection Resources . . . . . . . . . . 56
17.1. Authentication of Clients . . . . . . . . . . . . . . . 85 9.7.2. PUT for Collections . . . . . . . . . . . . . . . . 57
17.2. Denial of Service . . . . . . . . . . . . . . . . . . . 86 9.8. COPY Method . . . . . . . . . . . . . . . . . . . . . . 57
17.3. Security through Obscurity . . . . . . . . . . . . . . . 86 9.8.1. COPY for Non-collection Resources . . . . . . . . . 57
17.4. Privacy Issues Connected to Locks . . . . . . . . . . . 86 9.8.2. COPY for Properties . . . . . . . . . . . . . . . . 58
17.5. Privacy Issues Connected to Properties . . . . . . . . . 86 9.8.3. COPY for Collections . . . . . . . . . . . . . . . . 58
17.6. Reduction of Security due to Source Link . . . . . . . . 87 9.8.4. COPY and Overwriting Destination Resources . . . . . 59
17.7. Implications of XML External Entities . . . . . . . . . 87 9.8.5. Status Codes . . . . . . . . . . . . . . . . . . . . 60
17.8. Risks Connected with Lock Tokens . . . . . . . . . . . . 88 9.8.6. Example - COPY with Overwrite . . . . . . . . . . . 61
18. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 88 9.8.7. Example - COPY with No Overwrite . . . . . . . . . . 61
19. Intellectual Property . . . . . . . . . . . . . . . . . . . . 89 9.8.8. Example - COPY of a Collection . . . . . . . . . . . 62
20. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 89 9.9. MOVE Method . . . . . . . . . . . . . . . . . . . . . . 62
21. References . . . . . . . . . . . . . . . . . . . . . . . . . 90 9.9.1. MOVE for Properties . . . . . . . . . . . . . . . . 63
21.1. Normative References . . . . . . . . . . . . . . . . . . 90 9.9.2. MOVE for Collections . . . . . . . . . . . . . . . . 63
21.2. Informational References . . . . . . . . . . . . . . . . 91 9.9.3. MOVE and the Overwrite Header . . . . . . . . . . . 64
Appendix A. Appendices . . . . . . . . . . . . . . . . . . . . . 92 9.9.4. Status Codes . . . . . . . . . . . . . . . . . . . . 64
A.1. Appendix 1 - WebDAV Document Type Definition . . . . . . 92 9.9.5. Example - MOVE of a Non-Collection . . . . . . . . . 65
A.2. Appendix 2 - ISO 8601 Date and Time Profile . . . . . . 94 9.9.6. Example - MOVE of a Collection . . . . . . . . . . . 66
A.3. Appendix 3 - Notes on Processing XML Elements . . . . . 94 9.10. LOCK Method . . . . . . . . . . . . . . . . . . . . . . 67
A.3.1. Notes on Empty XML Elements . . . . . . . . . . . . 94 9.10.1. Creating a Lock on an Existing Resource . . . . . . 67
A.3.2. Notes on Illegal XML Processing . . . . . . . . . . 95 9.10.2. Refreshing Locks . . . . . . . . . . . . . . . . . . 67
A.4. Appendix 4 -- XML Namespaces for WebDAV . . . . . . . . 97 9.10.3. Depth and Locking . . . . . . . . . . . . . . . . . 68
A.4.1. Introduction . . . . . . . . . . . . . . . . . . . . 97 9.10.4. Locking Unmapped URLs . . . . . . . . . . . . . . . 68
A.4.2. Meaning of Qualified Names . . . . . . . . . . . . . 97 9.10.5. Lock Compatibility Table . . . . . . . . . . . . . . 69
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 9.10.6. LOCK Responses . . . . . . . . . . . . . . . . . . . 69
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 102 9.10.7. Example - Simple Lock Request . . . . . . . . . . . 70
Intellectual Property and Copyright Statements . . . . . . . . . 104 9.10.8. Example - Refreshing a Write Lock . . . . . . . . . 72
9.10.9. Example - Multi-Resource Lock Request . . . . . . . 73
9.11. UNLOCK Method . . . . . . . . . . . . . . . . . . . . . 74
9.11.1. Status Codes . . . . . . . . . . . . . . . . . . . . 74
9.11.2. Example - UNLOCK . . . . . . . . . . . . . . . . . . 75
10. HTTP Headers for Distributed Authoring . . . . . . . . . . . 76
10.1. DAV Header . . . . . . . . . . . . . . . . . . . . . . . 76
10.2. Depth Header . . . . . . . . . . . . . . . . . . . . . . 77
10.3. Destination Header . . . . . . . . . . . . . . . . . . . 78
10.4. If Header . . . . . . . . . . . . . . . . . . . . . . . 78
10.4.1. Purpose . . . . . . . . . . . . . . . . . . . . . . 78
10.4.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . 79
10.4.3. List Evaluation . . . . . . . . . . . . . . . . . . 80
10.4.4. Matching State Tokens and ETags . . . . . . . . . . 80
10.4.5. If Header and Non-DAV Aware Proxies . . . . . . . . 81
10.4.6. Example - No-tag Production . . . . . . . . . . . . 81
10.4.7. Example - using "Not" with No-tag Production . . . . 81
10.4.8. Example - causing a Condition to always evaluate
to True . . . . . . . . . . . . . . . . . . . . . . 82
10.4.9. Example - Tagged List If header in COPY . . . . . . 82
10.4.10. Example - Matching lock tokens with collection
locks . . . . . . . . . . . . . . . . . . . . . . . 82
10.4.11. Example - Matching ETags on unmapped URLs . . . . . 83
10.5. Lock-Token Header . . . . . . . . . . . . . . . . . . . 83
10.6. Overwrite Header . . . . . . . . . . . . . . . . . . . . 83
10.7. Timeout Request Header . . . . . . . . . . . . . . . . . 84
11. Status Code Extensions to HTTP/1.1 . . . . . . . . . . . . . 85
11.1. 207 Multi-Status . . . . . . . . . . . . . . . . . . . . 85
11.2. 422 Unprocessable Entity . . . . . . . . . . . . . . . . 85
11.3. 423 Locked . . . . . . . . . . . . . . . . . . . . . . . 85
11.4. 424 Failed Dependency . . . . . . . . . . . . . . . . . 85
11.5. 507 Insufficient Storage . . . . . . . . . . . . . . . . 85
12. Use of HTTP Status Codes . . . . . . . . . . . . . . . . . . 86
12.1. 412 Precondition Failed . . . . . . . . . . . . . . . . 86
12.2. 414 Request-URI Too Long . . . . . . . . . . . . . . . . 86
13. Multi-Status Response . . . . . . . . . . . . . . . . . . . . 87
13.1. Response Headers . . . . . . . . . . . . . . . . . . . . 87
13.2. Handling Redirected Child Resources . . . . . . . . . . 88
13.3. Internal Status Codes . . . . . . . . . . . . . . . . . 88
14. XML Element Definitions . . . . . . . . . . . . . . . . . . . 89
14.1. activelock XML Element . . . . . . . . . . . . . . . . . 89
14.2. allprop XML Element . . . . . . . . . . . . . . . . . . 89
14.3. collection XML Element . . . . . . . . . . . . . . . . . 89
14.4. depth XML Element . . . . . . . . . . . . . . . . . . . 89
14.5. error XML Element . . . . . . . . . . . . . . . . . . . 90
14.6. exclusive XML Element . . . . . . . . . . . . . . . . . 90
14.7. href XML Element . . . . . . . . . . . . . . . . . . . . 90
14.8. include XML Element . . . . . . . . . . . . . . . . . . 91
14.9. location XML Element . . . . . . . . . . . . . . . . . . 91
14.10. lockentry XML Element . . . . . . . . . . . . . . . . . 91
14.11. lockinfo XML Element . . . . . . . . . . . . . . . . . . 91
14.12. lockroot XML Element . . . . . . . . . . . . . . . . . . 92
14.13. lockscope XML Element . . . . . . . . . . . . . . . . . 92
14.14. locktoken XML Element . . . . . . . . . . . . . . . . . 92
14.15. locktype XML Element . . . . . . . . . . . . . . . . . . 92
14.16. multistatus XML Element . . . . . . . . . . . . . . . . 93
14.17. owner XML Element . . . . . . . . . . . . . . . . . . . 93
14.18. prop XML Element . . . . . . . . . . . . . . . . . . . . 93
14.19. propertyupdate XML Element . . . . . . . . . . . . . . . 94
14.20. propfind XML Element . . . . . . . . . . . . . . . . . . 94
14.21. propname XML Element . . . . . . . . . . . . . . . . . . 94
14.22. propstat XML Element . . . . . . . . . . . . . . . . . . 94
14.23. remove XML Element . . . . . . . . . . . . . . . . . . . 95
14.24. response XML Element . . . . . . . . . . . . . . . . . . 95
14.25. responsedescription XML Element . . . . . . . . . . . . 96
14.26. set XML Element . . . . . . . . . . . . . . . . . . . . 96
14.27. shared XML Element . . . . . . . . . . . . . . . . . . . 96
14.28. status XML Element . . . . . . . . . . . . . . . . . . . 96
14.29. timeout XML Element . . . . . . . . . . . . . . . . . . 97
14.30. write XML Element . . . . . . . . . . . . . . . . . . . 97
15. DAV Properties . . . . . . . . . . . . . . . . . . . . . . . 98
15.1. creationdate Property . . . . . . . . . . . . . . . . . 98
15.2. displayname Property . . . . . . . . . . . . . . . . . . 99
15.3. getcontentlanguage Property . . . . . . . . . . . . . . 99
15.4. getcontentlength Property . . . . . . . . . . . . . . . 100
15.5. getcontenttype Property . . . . . . . . . . . . . . . . 100
15.6. getetag Property . . . . . . . . . . . . . . . . . . . . 101
15.7. getlastmodified Property . . . . . . . . . . . . . . . . 101
15.8. lockdiscovery Property . . . . . . . . . . . . . . . . . 102
15.8.1. Example - Retrieving DAV:lockdiscovery . . . . . . . 103
15.9. resourcetype Property . . . . . . . . . . . . . . . . . 104
15.10. supportedlock Property . . . . . . . . . . . . . . . . . 105
15.10.1. Example - Retrieving DAV:supportedlock . . . . . . . 106
16. Precondition/Postcondition XML Elements . . . . . . . . . . . 107
17. XML Extensibility in DAV . . . . . . . . . . . . . . . . . . 111
18. DAV Compliance Classes . . . . . . . . . . . . . . . . . . . 113
18.1. Class 1 . . . . . . . . . . . . . . . . . . . . . . . . 113
18.2. Class 2 . . . . . . . . . . . . . . . . . . . . . . . . 113
18.3. Class 3 . . . . . . . . . . . . . . . . . . . . . . . . 113
19. Internationalization Considerations . . . . . . . . . . . . . 115
20. Security Considerations . . . . . . . . . . . . . . . . . . . 117
20.1. Authentication of Clients . . . . . . . . . . . . . . . 117
20.2. Denial of Service . . . . . . . . . . . . . . . . . . . 117
20.3. Security through Obscurity . . . . . . . . . . . . . . . 118
20.4. Privacy Issues Connected to Locks . . . . . . . . . . . 118
20.5. Privacy Issues Connected to Properties . . . . . . . . . 118
20.6. Implications of XML Entities . . . . . . . . . . . . . . 119
20.7. Risks Connected with Lock Tokens . . . . . . . . . . . . 119
20.8. Hosting Malicious Content . . . . . . . . . . . . . . . 120
21. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 121
21.1. New URI Schemes . . . . . . . . . . . . . . . . . . . . 121
21.2. XML Namespaces . . . . . . . . . . . . . . . . . . . . . 121
21.3. Message Header Fields . . . . . . . . . . . . . . . . . 121
21.3.1. DAV . . . . . . . . . . . . . . . . . . . . . . . . 121
21.3.2. Depth . . . . . . . . . . . . . . . . . . . . . . . 121
21.3.3. Destination . . . . . . . . . . . . . . . . . . . . 122
21.3.4. If . . . . . . . . . . . . . . . . . . . . . . . . . 122
21.3.5. Lock-Token . . . . . . . . . . . . . . . . . . . . . 122
21.3.6. Overwrite . . . . . . . . . . . . . . . . . . . . . 122
21.3.7. Timeout . . . . . . . . . . . . . . . . . . . . . . 123
22. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 124
23. Contributors to This Specification . . . . . . . . . . . . . 126
24. Authors of RFC2518 . . . . . . . . . . . . . . . . . . . . . 127
25. References . . . . . . . . . . . . . . . . . . . . . . . . . 128
25.1. Normative References . . . . . . . . . . . . . . . . . . 128
25.2. Informational References . . . . . . . . . . . . . . . . 129
Appendix A. Notes on Processing XML Elements . . . . . . . . . . 130
A.1. Notes on Empty XML Elements . . . . . . . . . . . . . . 130
A.2. Notes on Illegal XML Processing . . . . . . . . . . . . 130
A.3. Example - XML Syntax Error . . . . . . . . . . . . . . . 130
A.4. Example - Unexpected XML Element . . . . . . . . . . . . 131
Appendix B. Notes on HTTP Client Compatibility . . . . . . . . . 132
Appendix C. The 'opaquelocktoken' Scheme and URIs . . . . . . . 133
Appendix D. Lock-null Resources . . . . . . . . . . . . . . . . 134
D.1. Guidance for Clients Using LOCK to Create Resources . . 134
Appendix E. Guidance for Clients Desiring to Authenticate . . . 136
Appendix F. Summary of changes from RFC2518 . . . . . . . . . . 138
F.1. Changes for both Client and Server Implementations . . . 138
F.2. Changes for Server Implementations . . . . . . . . . . . 139
F.3. Other Changes . . . . . . . . . . . . . . . . . . . . . 140
Appendix G. Change Log (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . 142
G.1. Changes from -05 to -06 . . . . . . . . . . . . . . . . 142
G.2. Changes in -07 . . . . . . . . . . . . . . . . . . . . . 142
G.3. Changes in -08 . . . . . . . . . . . . . . . . . . . . . 143
G.4. Changes in -09 . . . . . . . . . . . . . . . . . . . . . 144
G.5. Changes in -10 . . . . . . . . . . . . . . . . . . . . . 145
G.6. Changes in -11 . . . . . . . . . . . . . . . . . . . . . 145
G.7. Changes in -12 . . . . . . . . . . . . . . . . . . . . . 145
G.8. Changes in -13 . . . . . . . . . . . . . . . . . . . . . 146
G.9. Changes in -14 . . . . . . . . . . . . . . . . . . . . . 146
G.10. Changes in -15 . . . . . . . . . . . . . . . . . . . . . 146
G.11. Changes in -16 . . . . . . . . . . . . . . . . . . . . . 146
G.12. Changes in -17 . . . . . . . . . . . . . . . . . . . . . 147
G.13. Changes in -18 . . . . . . . . . . . . . . . . . . . . . 147
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 148
Intellectual Property and Copyright Statements . . . . . . . . . 149
1. Introduction 1. Introduction
This document describes an extension to the HTTP/1.1 protocol that This document describes an extension to the HTTP/1.1 protocol that
allows clients to perform remote web content authoring operations. allows clients to perform remote web content authoring operations.
This extension provides a coherent set of methods, headers, request This extension provides a coherent set of methods, headers, request
entity body formats, and response entity body formats that provide entity body formats, and response entity body formats that provide
operations for: operations for:
Properties: The ability to create, remove, and query information Properties: The ability to create, remove, and query information
about Web pages, such as their authors, creation dates, etc. Also, about Web pages, such as their authors, creation dates, etc.
the ability to link pages of any media type to related pages.
Collections: The ability to create sets of documents and to retrieve Collections: The ability to create sets of documents and to retrieve
a hierarchical membership listing (like a directory listing in a file a hierarchical membership listing (like a directory listing in a file
system). system).
Locking: The ability to keep more than one person from working on a Locking: The ability to keep more than one person from working on a
document at the same time. This prevents the "lost update problem," document at the same time. This prevents the "lost update problem",
in which modifications are lost as first one author then another in which modifications are lost as first one author then another
writes changes without merging the other author's changes. writes changes without merging the other author's changes.
Namespace Operations: The ability to instruct the server to copy and Namespace Operations: The ability to instruct the server to copy and
move Web resources. move Web resources, operations which change the mapping from URLs to
resources.
Requirements and rationale for these operations are described in a Requirements and rationale for these operations are described in a
companion document, "Requirements for a Distributed Authoring and companion document, "Requirements for a Distributed Authoring and
Versioning Protocol for the World Wide Web" [RFC2291]. Versioning Protocol for the World Wide Web" [RFC2291].
The sections below provide a detailed introduction to resource This document does not specify the versioning operations suggested by
properties (Section 4), collections of resources (Section 5), and [RFC2291]. That work was done in a separate document, "Versioning
locking operations (Section 6). These sections introduce the Extensions to WebDAV" [RFC3253].
abstractions manipulated by the WebDAV-specific HTTP methods
described in Section 8, "HTTP Methods for Distributed Authoring".
In HTTP/1.1, method parameter information was exclusively encoded in
HTTP headers. Unlike HTTP/1.1, WebDAV encodes method parameter
information either in an Extensible Markup Language (XML) [REC-XML]
request entity body, or in an HTTP header. The use of XML to encode
method parameters was motivated by the ability to add extra XML
elements to existing structures, providing extensibility; and by
XML's ability to encode information in ISO 10646 character sets,
providing internationalization support. As a rule of thumb,
parameters are encoded in XML entity bodies when they have unbounded
length, or when they may be shown to a human user and hence require
encoding in an ISO 10646 character set. Otherwise, parameters are
encoded within HTTP headers. Section 9 describes the new HTTP
headers used with WebDAV methods.
In addition to encoding method parameters, XML is used in WebDAV to
encode the responses from methods, providing the extensibility and
internationalization advantages of XML for method output, as well as
input.
XML elements used in this specification are defined in Section 12. The sections below provide a detailed introduction to various WebDAV
abstractions: resource properties (Section 4), collections of
resources (Section 5), locks (Section 6) in general and write locks
(Section 7) specifically.
The XML namespace extension (Appendix A.4) is also used in this These abstractions are manipulated by the WebDAV-specific HTTP
specification in order to allow for new XML elements to be added methods (Section 9) and the extra HTTP headers (Section 10) used with
without fear of colliding with other element names. WebDAV methods. General considerations for handling HTTP requests
and responses in WebDAV are found in Section 8.
While the status codes provided by HTTP/1.1 are sufficient to While the status codes provided by HTTP/1.1 are sufficient to
describe most error conditions encountered by WebDAV methods, there describe most error conditions encountered by WebDAV methods, there
are some errors that do not fall neatly into the existing categories. are some errors that do not fall neatly into the existing categories.
New status codes developed for the WebDAV methods are defined in This specification defines extra status codes developed for WebDAV
Section 10. Since some WebDAV methods may operate over many methods (Section 11) and describes existing HTTP status codes
resources, the Multi-Status response has been introduced to return (Section 12) as used in WebDAV. Since some WebDAV methods may
status information for multiple resources. The Multi-Status response operate over many resources, the Multi-Status response (Section 13)
is described in Section 11. has been introduced to return status information for multiple
resources. Finally, this version of WebDAV introduces precondition
and postcondition (Section 16) XML elements in error response bodies.
WebDAV employs the property mechanism to store information about the WebDAV uses XML ([REC-XML]) for property names and some values, and
current state of the resource. For example, when a lock is taken out also uses XML to marshal complicated requests and responses. This
on a resource, a lock information property describes the current specification contains DTD and text definitions of all all properties
state of the lock. Section 13 defines the properties used within the (Section 15) and all other XML elements (Section 14) used in
WebDAV specification. marshalling. WebDAV includes a few special rules on extending
WebDAV XML marshalling in backwards-compatible ways (Section 17).
Finishing off the specification are sections on what it means to be Finishing off the specification are sections on what it means for a
compliant with this specification (Section 15), on resource to be compliant with this specification (Section 18), on
internationalization support (Section 16), and on security internationalization support (Section 19), and on security
(Section 17). (Section 20).
2. Notational Conventions 2. Notational Conventions
Since this document describes a set of extensions to the HTTP/1.1 Since this document describes a set of extensions to the HTTP/1.1
protocol, the augmented BNF used herein to describe protocol elements protocol, the augmented BNF used herein to describe protocol elements
is exactly the same as described in section 2.1 of [RFC2068]. Since is exactly the same as described in Section 2.1 of [RFC2616],
this augmented BNF uses the basic production rules provided in including the rules about implied linear white-space. Since this
section 2.2 of [RFC2068], these rules apply to this document as well. augmented BNF uses the basic production rules provided in Section 2.2
of [RFC2616], these rules apply to this document as well.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in [RFC2119].
Note that in natural language, a property like the "creationdate"
property in the "DAV:" XML namespace is sometimes referred to as
"DAV:creationdate" for brevity.
3. Terminology 3. Terminology
"URI"/"URL" - A Uniform Resource Identifier and Uniform Resource URI/URL - A Uniform Resource Identifier and Uniform Resource Locator,
Locator, respectively. These terms (and the distinction between respectively. These terms (and the distinction between them) are
them) are defined in [RFC2396]. defined in [RFC3986].
"Collection" - A resource that contains a set of URIs, termed member URI/URL Mapping - A relation between an absolute URI and a resource.
URIs, which identify member resources and meets the requirements in Since a resource can represent items that are not network
Section 5 of this specification. retrievable, as well as those that are, it is possible for a resource
to have zero, one, or many URI mappings. Mapping a resource to an
"http" scheme URI makes it possible to submit HTTP protocol requests
to the resource using the URI.
"Member URI" - A URI which is a member of the set of URIs contained Path Segment - Informally, the characters found between slashes ("/")
by a collection. in a URI. Formally, as defined in Section 3.3 of [RFC3986].
"Internal Member URI" - A Member URI that is immediately relative to Collection - Informally, a resource that also acts as a container of
the URI of the collection (the definition of immediately relative is references to child resources. Formally, a resource that contains a
given in Section 5.2). set of mappings between path segments and resources and meets the
requirements defined in Section 5.
"Property" - A name/value pair that contains descriptive information Internal Member (of a Collection) - Informally, a child resource of a
collection. Formally, a resource referenced by a path segment
mapping contained in the collection.
Internal Member URL (of a Collection) - A URL of an internal member,
consisting of the URL of the collection (including trailing slash)
plus the path segment identifying the internal member.
Member (of a Collection) - Informally, a "descendant" of a
collection. Formally, an internal member of the collection, or,
recursively, a member of an internal member.
Member URL (of a Collection) - A URL that is either an internal
member URL of the collection itself, or is an internal member URL of
a member of that collection.
Property - A name/value pair that contains descriptive information
about a resource. about a resource.
"Live Property" - A property whose semantics and syntax are enforced Live Property - A property whose semantics and syntax are enforced by
by the server. For example, the live "getcontentlength" property has the server. For example, the live property DAV:getcontentlength has
its value, the length of the entity returned by a GET request, its value, the length of the entity returned by a GET request,
automatically calculated by the server. automatically calculated by the server.
"Dead Property" - A property whose semantics and syntax are not Dead Property - A property whose semantics and syntax are not
enforced by the server. The server only records the value of a dead enforced by the server. The server only records the value of a dead
property; the client is responsible for maintaining the consistency property; the client is responsible for maintaining the consistency
of the syntax and semantics of a dead property. of the syntax and semantics of a dead property.
"Null Resource" - A resource which responds with a 404 (Not Found) to Principal - A "principal" is a distinct human or computational actor
any HTTP/1.1 or DAV method except for PUT, MKCOL, OPTIONS and LOCK. that initiates access to network resources.
A NULL resource MUST NOT appear as a member of its parent collection.
State Token - A URI which represents a state of a resource. Lock
tokens are the only state tokens defined in this specification.
4. Data Model for Resource Properties 4. Data Model for Resource Properties
4.1. The Resource Property Model 4.1. The Resource Property Model
Properties are pieces of data that describe the state of a resource. Properties are pieces of data that describe the state of a resource.
Properties are data about data. Properties are data about data.
Properties are used in distributed authoring environments to provide Properties are used in distributed authoring environments to provide
for efficient discovery and management of resources. For example, a for efficient discovery and management of resources. For example, a
'subject' property might allow for the indexing of all resources by 'subject' property might allow for the indexing of all resources by
their subject, and an 'author' property might allow for the discovery their subject, and an 'author' property might allow for the discovery
of what authors have written which documents. of what authors have written which documents.
The DAV property model consists of name/value pairs. The name of a The DAV property model consists of name/value pairs. The name of a
property identifies the property's syntax and semantics, and provides property identifies the property's syntax and semantics, and provides
an address by which to refer to its syntax and semantics. an address by which to refer to its syntax and semantics.
There are two categories of properties: "live" and "dead". A live There are two categories of properties: "live" and "dead". A live
property has its syntax and semantics enforced by the server. Live property has its syntax and semantics enforced by the server. Live
properties include cases where a) the value of a property is read- properties include cases where a) the value of a property is
only, maintained by the server, and b) the value of the property is protected, maintained by the server, and b) the value of the property
maintained by the client, but the server performs syntax checking on is maintained by the client, but the server performs syntax checking
submitted values. All instances of a given live property MUST comply on submitted values. All instances of a given live property MUST
with the definition associated with that property name. A dead comply with the definition associated with that property name. A
property has its syntax and semantics enforced by the client; the dead property has its syntax and semantics enforced by the client;
server merely records the value of the property verbatim. the server merely records the value of the property verbatim.
4.2. Existing Metadata Proposals
Properties have long played an essential role in the maintenance of
large document repositories, and many current proposals contain some
notion of a property, or discuss web metadata more generally. These
include PICS [REC-PICS], PICS-NG, XML, Web Collections, and several
proposals on representing relationships within HTML. Work on PICS-NG
and Web Collections has been subsumed by the Resource Description
Framework (RDF) metadata activity of the World Wide Web Consortium.
RDF consists of a network-based data model and an XML representation
of that model.
Some proposals come from a digital library perspective. These
include the Dublin Core [RFC2413] metadata set and the Warwick
Framework [WF], a container architecture for different metadata
schemas. The literature includes many examples of metadata,
including MARC [USMARC], a bibliographic metadata format, and a
technical report bibliographic format employed by the Dienst system
[RFC1807]. Additionally, the proceedings from the first IEEE
Metadata conference describe many community-specific metadata sets.
Participants of the 1996 Metadata II Workshop in Warwick, UK [WF],
noted that "new metadata sets will develop as the networked
infrastructure matures" and "different communities will propose,
design, and be responsible for different types of metadata." These
observations can be corroborated by noting that many community-
specific sets of metadata already exist, and there is significant
motivation for the development of new forms of metadata as many
communities increasingly make their data available in digital form,
requiring a metadata format to assist data location and cataloging.
4.3. Properties and HTTP Headers 4.2. Properties and HTTP Headers
Properties already exist, in a limited sense, in HTTP message Properties already exist, in a limited sense, in HTTP message
headers. However, in distributed authoring environments a relatively headers. However, in distributed authoring environments a relatively
large number of properties are needed to describe the state of a large number of properties are needed to describe the state of a
resource, and setting/returning them all through HTTP headers is resource, and setting/returning them all through HTTP headers is
inefficient. Thus a mechanism is needed which allows a principal to inefficient. Thus a mechanism is needed which allows a principal to
identify a set of properties in which the principal is interested and identify a set of properties in which the principal is interested and
to set or retrieve just those properties. to set or retrieve just those properties.
4.4. Property Values 4.3. Property Values
The value of a property when expressed in XML MUST be well formed. The value of a property is always a (well-formed) XML fragment.
XML has been chosen because it is a flexible, self-describing, XML has been chosen because it is a flexible, self-describing,
structured data format that supports rich schema definitions, and structured data format that supports rich schema definitions, and
because of its support for multiple character sets. XML's self- because of its support for multiple character sets. XML's self-
describing nature allows any property's value to be extended by describing nature allows any property's value to be extended by
adding new elements. Older clients will not break when they adding elements. Clients will not break when they encounter
encounter extensions because they will still have the data specified extensions because they will still have the data specified in the
in the original schema and will ignore elements they do not original schema and MUST ignore elements they do not understand.
understand. XML's support for multiple character sets allows any
human-readable property to be encoded and read in a character set
familiar to the user. XML's support for multiple human languages,
using the "xml:lang" attribute, handles cases where the same
character set is employed by multiple human languages.
4.5. Property Names XML's support for multiple character sets allows any human-readable
property to be encoded and read in a character set familiar to the
user. XML's support for multiple human languages, using the "xml:
lang" attribute, handles cases where the same character set is
employed by multiple human languages. Note that xml:lang scope is
recursive, so an xml:lang attribute on any element containing a
property name element applies to the property value unless it has
been overridden by a more locally scoped attribute. Note that a
property only has one value, in one language (or language MAY be left
undefined), not multiple values in different languages or a single
value in multiple languages.
A property is always represented with an XML element consisting of
the property name, called the "property name element". The simplest
example is an empty property, which is different from a property that
does not exist:
<R:title xmlns:R="http://www.example.com/ns/"></R:title>
The value of the property appears inside the property name element.
The value may be any kind of well-formed XML content, including both
text-only and mixed content. Servers MUST preserve the following XML
Information Items (using the terminology from [REC-XML-INFOSET]) in
storage and transmission of dead properties:
For the property name Element Information Item itself:
[namespace name]
[local name]
[attributes] named "xml:lang" or any such attribute in scope
[children] of type element or character
On all Element Information Items in the property value:
[namespace name]
[local name]
[attributes]
[children] of type element or character
On Attribute Information Items in the property value:
[namespace name]
[local name]
[normalized value]
On Character Information Items in the property value:
[character code]
Since prefixes are used in some XML vocabularies (XPath and XML
Schema, for example), servers SHOULD preserve, for any Information
Item in the value:
[prefix]
XML Infoset attributes not listed above MAY be preserved by the
server, but clients MUST NOT rely on them being preserved. The above
rules would also apply by default to live properties, unless defined
otherwise.
Servers MUST ignore the XML attribute xml:space if present and never
use it to change white space handling. White space in property
values is significant.
4.3.1. Example - Property with Mixed Content
Consider a dead property 'author' created by the client as follows:
<D:prop xml:lang="en" xmlns:D="DAV:">
<x:author xmlns:x='http://example.com/ns'>
<x:name>Jane Doe</x:name>
<!-- Jane's contact info -->
<x:uri type='email'
added='2005-11-26'>mailto:jane.doe@example.com</x:uri>
<x:uri type='web'
added='2005-11-27'>http://www.example.com</x:uri>
<x:notes xmlns:h='http://www.w3.org/1999/xhtml'>
Jane has been working way <h:em>too</h:em> long on the
long-awaited revision of <![CDATA[<RFC2518>]]>.
</x:notes>
</x:author>
</D:prop>
When this property is requested, a server might return:
<D:prop xmlns:D='DAV:'><author
xml:lang='en'
xmlns:x='http://example.com/ns'
xmlns='http://example.com/ns'
xmlns:h='http://www.w3.org/1999/xhtml'>
<x:name>Jane Doe</x:name>
<x:uri added="2005-11-26" type="email"
>mailto:jane.doe@example.com</x:uri>
<x:uri added="2005-11-27" type="web"
>http://www.example.com</x:uri>
<x:notes>
Jane has been working way <h:em>too</h:em> long on the
long-awaited revision of &lt;RFC2518&gt;.
</x:notes>
</author>
</D:prop>
Note in this example:
o The [prefix] for the property name itself was not preserved, being
non-significant, all other [prefix] values have been preserved,
o attribute values have been rewritten with double quotes instead of
single quotes (quoting style is not significant), and attribute
order has not been preserved,
o the xml:lang attribute has been returned on the property name
element itself (it was in scope when the property was set, but the
exact position in the response is not considered significant as
long as it is in scope),
o whitespace between tags has been preserved everywhere (whitespace
between attributes not so),
o CDATA encapsulation was replaced with character escaping (the
reverse would also be legal),
o the comment item was stripped (as would have been a processing
instruction item).
Implementation note: there are cases such as editing scenarios where
clients may require that XML content is preserved character-by-
character (such as attribute ordering or quoting style). In this
case, clients should consider using a text-only property value by
escaping all characters that have a special meaning in XML parsing.
4.4. Property Names
A property name is a universally unique identifier that is associated A property name is a universally unique identifier that is associated
with a schema that provides information about the syntax and with a schema that provides information about the syntax and
semantics of the property. semantics of the property.
Because a property's name is universally unique, clients can depend Because a property's name is universally unique, clients can depend
upon consistent behavior for a particular property across multiple upon consistent behavior for a particular property across multiple
resources, on the same and across different servers, so long as that resources, on the same and across different servers, so long as that
property is "live" on the resources in question, and the property is "live" on the resources in question, and the
implementation of the live property is faithful to its definition. implementation of the live property is faithful to its definition.
The XML namespace mechanism, which is based on URIs [RFC2396], is The XML namespace mechanism, which is based on URIs ([RFC3986]), is
used to name properties because it prevents namespace collisions and used to name properties because it prevents namespace collisions and
provides for varying degrees of administrative control. provides for varying degrees of administrative control.
The property namespace is flat; that is, no hierarchy of properties The property namespace is flat; that is, no hierarchy of properties
is explicitly recognized. Thus, if a property A and a property A/B is explicitly recognized. Thus, if a property A and a property A/B
exist on a resource, there is no recognition of any relationship exist on a resource, there is no recognition of any relationship
between the two properties. It is expected that a separate between the two properties. It is expected that a separate
specification will eventually be produced which will address issues specification will eventually be produced which will address issues
relating to hierarchical properties. relating to hierarchical properties.
Finally, it is not possible to define the same property twice on a Finally, it is not possible to define the same property twice on a
single resource, as this would cause a collision in the resource's single resource, as this would cause a collision in the resource's
property namespace. property namespace.
4.6. Media Independent Links 4.5. Source Resources and Output Resources
Although HTML resources support links to other resources, the Web Some HTTP resources are dynamically generated by the server. For
needs more general support for links between resources of any media these resources, there presumably exists source code somewhere
type (media types are also known as MIME types, or content types). governing how that resource is generated. The relationship of source
WebDAV provides such links. A WebDAV link is a special type of files to output HTTP resources may be one to one, one to many, many
property value, formally defined in Section 12.4, that allows typed to one or many to many. There is no mechanism in HTTP to determine
connections to be established between resources of any media type. whether a resource is even dynamic, let alone where its source files
The property value consists of source and destination Uniform exist or how to author them. Although this problem would usefully be
Resource Identifiers (URIs); the property name identifies the link solved, interoperable WebDAV implementations have been widely
type. deployed without actually solving this problem, by dealing only with
static resources. Thus, the source vs. output problem is not solved
in this specification and has been deferred to a separate document.
5. Collections of Web Resources 5. Collections of Web Resources
This section provides a description of a new type of Web resource, This section provides a description of a type of Web resource, the
the collection, and discusses its interactions with the HTTP URL collection, and discusses its interactions with the HTTP URL
namespace. The purpose of a collection resource is to model namespace and with HTTP methods. The purpose of a collection
collection-like objects (e.g., file system directories) within a resource is to model collection-like objects (e.g., file system
server's namespace. directories) within a server's namespace.
All DAV compliant resources MUST support the HTTP URL namespace model All DAV compliant resources MUST support the HTTP URL namespace model
specified herein. specified herein.
5.1. HTTP URL Namespace Model 5.1. HTTP URL Namespace Model
The HTTP URL namespace is a hierarchical namespace where the The HTTP URL namespace is a hierarchical namespace where the
hierarchy is delimited with the "/" character. hierarchy is delimited with the "/" character.
An HTTP URL namespace is said to be consistent if it meets the An HTTP URL namespace is said to be consistent if it meets the
following conditions: for every URL in the HTTP hierarchy there following conditions: for every URL in the HTTP hierarchy there
exists a collection that contains that URL as an internal member. exists a collection that contains that URL as an internal member URL.
The root, or top-level collection of the namespace under The root, or top-level collection of the namespace under
consideration is exempt from the previous rule. consideration, is exempt from the previous rule. The top-level
collection of the namespace under consideration is not necessarily
the collection identified by the absolute path '/', it may be
identified by one or more path segments (e.g. /servlets/webdav/...)
Neither HTTP/1.1 nor WebDAV require that the entire HTTP URL Neither HTTP/1.1 nor WebDAV require that the entire HTTP URL
namespace be consistent. However, certain WebDAV methods are namespace be consistent -- a WebDAV-compatible resource may not have
prohibited from producing results that cause namespace a parent collection. However, certain WebDAV methods are prohibited
inconsistencies. from producing results that cause namespace inconsistencies.
Although implicit in [RFC2068] and [RFC2396], any resource, including As is implicit in [RFC2616] and [RFC3986], any resource, including
collection resources, MAY be identified by more than one URI. For collection resources, MAY be identified by more than one URI. For
example, a resource could be identified by multiple HTTP URLs. example, a resource could be identified by multiple HTTP URLs.
5.2. Collection Resources 5.2. Collection Resources
A collection is a resource whose state consists of at least a list of Collection resources differ from other resources in that they also
internal member URIs and a set of properties, but which may have act as containers. Some HTTP methods apply only to a collection, but
additional state such as entity bodies returned by GET. An internal some apply to some or all of the resources inside the container
member URI MUST be immediately relative to a base URI of the defined by the collection. When the scope of a method is not clear,
collection. That is, the internal member URI is equal to a the client can specify what depth to apply. Depth can be either zero
containing collection's URI plus an additional segment for non- levels in (only the collection), one level (the collection and
collection resources, or additional segment plus trailing slash "/" directly contained resources) or infinite levels (the collection and
for collection resources, where segment is defined in section 3.3 of all contained resources recursively).
[RFC2396].
Any given internal member URI MUST only belong to the collection
once, i.e., it is illegal to have multiple instances of the same URI
in a collection. Properties defined on collections behave exactly as
do properties on non-collection resources.
For all WebDAV compliant resources A and B, identified by URIs U and
V, for which U is immediately relative to V, B MUST be a collection
that has U as an internal member URI. So, if the resource with URL
http://foo.com/bar/blah is WebDAV compliant and if the resource with
URL http://foo.com/bar/ is WebDAV compliant then the resource with
URL http://foo.com/bar/ must be a collection and must contain URL
http://foo.com/bar/blah as an internal member.
Collection resources MAY list the URLs of non-WebDAV compliant
children in the HTTP URL namespace hierarchy as internal members but
are not required to do so. For example, if the resource with URL
http://foo.com/bar/blah is not WebDAV compliant and the URL
http://foo.com/bar/ identifies a collection then URL
http://foo.com/bar/blah may or may not be an internal member of the
collection with URL http://foo.com/bar/.
If a WebDAV compliant resource has no WebDAV compliant children in
the HTTP URL namespace hierarchy then the WebDAV compliant resource
is not required to be a collection.
There is a standing convention that when a collection is referred to
by its name without a trailing slash, the trailing slash is
automatically appended. Due to this, a resource may accept a URI
without a trailing "/" to point to a collection. In this case it
SHOULD return a content-location header in the response pointing to
the URI ending with the "/". For example, if a client invokes a
method on http://foo.bar/blah (no trailing slash), the resource
http://foo.bar/blah/ (trailing slash) may respond as if the operation
were invoked on it, and should return a content-location header with
http://foo.bar/blah/ in it. In general clients SHOULD use the "/"
form of collection names.
A resource MAY be a collection but not be WebDAV compliant. That is,
the resource may comply with all the rules set out in this
specification regarding how a collection is to behave without
necessarily supporting all methods that a WebDAV compliant resource
is required to support. In such a case the resource may return the
DAV:resourcetype property with the value DAV:collection but MUST NOT
return a DAV header containing the value "1" on an OPTIONS response.
5.3. Creation and Retrieval of Collection Resources
This document specifies the MKCOL method to create new collection A collection's state consists of at least a set of mappings between
resources, rather than using the existing HTTP/1.1 PUT or POST path segments and resources, and a set of properties on the
method, for the following reasons: collection itself. In this document, a resource B will be said to be
contained in the collection resource A if there is a path segment
mapping which maps to B and which is contained in A. A collection
MUST contain at most one mapping for a given path segment, i.e., it
is illegal to have the same path segment mapped to more than one
resource.
In HTTP/1.1, the PUT method is defined to store the request body at Properties defined on collections behave exactly as do properties on
the location specified by the Request-URI. While a description non-collection resources. A collection MAY have additional state
format for a collection can readily be constructed for use with PUT, such as entity bodies returned by GET.
the implications of sending such a description to the server are
undesirable. For example, if a description of a collection that
omitted some existing resources were PUT to a server, this might be
interpreted as a command to remove those members. This would extend
PUT to perform DELETE functionality, which is undesirable since it
changes the semantics of PUT, and makes it difficult to control
DELETE functionality with an access control scheme based on methods.
While the POST method is sufficiently open-ended that a "create a For all WebDAV compliant resources A and B, identified by URLs "U"
collection" POST command could be constructed, this is undesirable and "V" respectively, such that "V" is equal to "U/SEGMENT", A MUST
because it would be difficult to separate access control for be a collection that contains a mapping from "SEGMENT" to B. So, if
collection creation from other uses of POST. resource B with URL "http://example.com/bar/blah" is WebDAV compliant
and if resource A with URL "http://example.com/bar/" is WebDAV
compliant, then resource A must be a collection and must contain
exactly one mapping from "blah" to B.
The exact definition of the behavior of GET and PUT on collections is Although commonly a mapping consists of a single segment and a
defined later in this document. resource, in general, a mapping consists of a set of segments and a
resource. This allows a server to treat a set of segments as
equivalent (i.e. either all of the segments are mapped to the same
resource, or none of the segments are mapped to a resource). For
example, a server that performs case-folding on segments will treat
the segments "ab", "Ab", "aB", and "AB" as equivalent. A client can
then use any of these segments to identify the resource. Note that a
PROPFIND result will select one of these equivalent segments to
identify the mapping, so there will be one PROPFIND response element
per mapping, not one per segment in the mapping.
5.4. Source Resources and Output Resources Collection resources MAY have mappings to non-WebDAV compliant
resources in the HTTP URL namespace hierarchy but are not required to
do so. For example, if resource X with URL
"http://example.com/bar/blah" is not WebDAV compliant and resource A
with "URL http://example.com/bar/" identifies a WebDAV collection,
then A may or may not have a mapping from "blah" to X.
For many resources, the entity returned by a GET method exactly If a WebDAV compliant resource has no WebDAV compliant internal
matches the persistent state of the resource, for example, a GIF file members in the HTTP URL namespace hierarchy then the WebDAV compliant
stored on a disk. For this simple case, the URI at which a resource resource is not required to be a collection.
is accessed is identical to the URI at which the source (the
persistent state) of the resource is accessed. This is also the case
for HTML source files that are not processed by the server prior to
transmission.
However, the server can sometimes process HTML resources before they There is a standing convention that when a collection is referred to
are transmitted as a return entity body. For example, a server-side- by its name without a trailing slash, the server MAY handle the
include directive within an HTML file might instruct a server to request as if the trailing slash were present. In this case it
replace the directive with another value, such as the current date. SHOULD return a Content-Location header in the response, pointing to
In this case, what is returned by GET (HTML plus date) differs from the URL ending with the "/". For example, if a client invokes a
the persistent state of the resource (HTML plus directive). method on http://example.com/blah (no trailing slash), the server may
Typically there is no way to access the HTML resource containing the respond as if the operation were invoked on http://example.com/blah/
unprocessed directive. (trailing slash), and should return a Content-Location header with
the value http://example.com/blah/. Wherever a server produces a URL
referring to a collection, the server SHOULD include the trailing
slash. In general clients SHOULD use the trailing slash form of
collection names. If clients do not use the trailing slash form the
client needs to be prepared to see a redirect response. Clients will
find the DAV:resourcetype property more reliable than the URL to find
out if a resource is a collection.
Sometimes the entity returned by GET is the output of a data- Clients MUST be able to support the case where WebDAV resources are
producing process that is described by one or more source resources contained inside non-WebDAV resources. For example, if a OPTIONS
(that may not even have a location in the URI namespace). A single response from "http://example.com/servlet/dav/collection" indicates
data-producing process may dynamically generate the state of a WebDAV support, the client cannot assume that
potentially large number of output resources. An example of this is "http://example.com/servlet/dav/" or its parent necessarily are
a CGI script that describes a "finger" gateway process that maps part WebDAV collections.
of the namespace of a server into finger requests, such as
http://www.foo.bar.org/finger_gateway/user@host.
In the absence of distributed authoring capabilities, it is A typical scenario in which mapped URLs do not appear as members of
acceptable to have no mapping of source resource(s) to the URI their parent collection is the case where a server allows links or
namespace. In fact, preventing access to the source resource(s) has redirects to non-WebDAV resources. For instance, "/col/link" might
desirable security benefits. However, if remote editing of the not appear as a member of "/col/", although the server would respond
source resource(s) is desired, the source resource(s) should be given with a 302 status to a GET request to "/col/link", thus the URL
a location in the URI namespace. This source location should not be "/col/link" would indeed be mapped. Similarly, a dynamically-
one of the locations at which the generated output is retrievable, generated page might have a URL mapping from "/col/index.html", thus
since in general it is impossible for the server to differentiate this resource might respond with a 200 OK to a GET request yet not
requests for source resources from requests for process output appear as a member of "/col/".
resources. There is often a many-to-many relationship between source
resources and output resources.
On WebDAV compliant servers the URI of the source resource(s) may be Some mappings to even WebDAV-compliant resources might not appear in
stored in a link on the output resource with type DAV:source (see the parent collection. An example for this case are servers that
Section 13.10 for a description of the source link property). support multiple alias URLs for each WebDAV compliant resource. A
Storing the source URIs in links on the output resources places the server may implement case-insensitive URLs, thus "/col/a" and
burden of discovering the source on the authoring client. Note that "/col/A" identify the same resource, yet only either "a" or "A" are
the value of a source link is not guaranteed to point to the correct reported upon listing the members of "/col". In cases where a server
source. Source links may break or incorrect values may be entered. treats a set of segments as equivalent, the server MUST expose only
Also note that not all servers will allow the client to set the one preferred segment per mapping, consistently chosen, in PROPFIND
source link value. For example a server which generates source links responses.
on the fly for its CGI files will most likely not allow a client to
set the source link value.
6. Locking 6. Locking
The ability to lock a resource provides a mechanism for serializing The ability to lock a resource provides a mechanism for serializing
access to that resource. Using a lock, an authoring client can access to that resource. Using a lock, an authoring client can
provide a reasonable guarantee that another principal will not modify provide a reasonable guarantee that another principal will not modify
a resource while it is being edited. In this way, a client can a resource while it is being edited. In this way, a client can
prevent the "lost update" problem. prevent the "lost update" problem.
This specification allows locks to vary over two client-specified This specification allows locks to vary over two client-specified
parameters, the number of principals involved (exclusive vs. shared) parameters, the number of principals involved (exclusive vs. shared)
and the type of access to be granted. This document defines locking and the type of access to be granted. This document defines locking
for only one access type, write. However, the syntax is extensible, for only one access type, write. However, the syntax is extensible,
and permits the eventual specification of locking for other access and permits the eventual specification of locking for other access
types. types.
6.1. Exclusive Vs. Shared Locks 6.1. Lock Model
The most basic form of lock is an exclusive lock. This is a lock This section provides a concise model for how locking behaves. Later
where the access right in question is only granted to a single sections will provide more detail on some of the concepts and refer
principal. The need for this arbitration results from a desire to back to these model statements. Normative statements related to LOCK
avoid having to merge results. and UNLOCK method handling can be found in the sections on those
methods, whereas normative statements that cover any method are
gathered here.
1. A lock either directly or indirectly locks a resource.
2. A resource becomes directly locked when a LOCK request to a URL
of that resource creates a new lock. The "lock-root" of the new
lock is that URL. If at the time of the request, the URL is not
mapped to a resource, a new empty resource is created and
directly locked.
3. An exclusive lock (Section 6.2) conflicts with any other kind of
lock on the same resource, whether either lock is direct or
indirect. A server MUST NOT create conflicting locks on a
resource.
4. For a collection that is locked with a depth-infinity lock L, all
member resources are indirectly locked. Changes in membership of
a such a collection affect the set of indirectly locked
resources:
* If a member resource is added to the collection, the new
member resource MUST NOT already have a conflicting lock,
because the new resource MUST become indirectly locked by L.
* If a member resource stops being a member of the collection,
then the resource MUST no longer be indirectly locked by L.
5. Each lock is identified by a single globally unique lock token
(Section 6.5).
6. An UNLOCK request deletes the lock with the specified lock token.
After a lock is deleted, no resource is locked by that lock.
7. A lock token is "submitted" in a request when it appears in an
"If" header (the Write Lock (Section 7) section discusses when
token submission is required for write locks).
8. If a request causes the lock-root of any lock to become an
unmapped URL, then the lock MUST also be deleted by that request.
6.2. Exclusive Vs. Shared Locks
The most basic form of lock is an exclusive lock. Exclusive locks
avoid having to deal with content change conflicts, without requiring
any coordination other than the methods described in this
specification.
However, there are times when the goal of a lock is not to exclude However, there are times when the goal of a lock is not to exclude
others from exercising an access right but rather to provide a others from exercising an access right but rather to provide a
mechanism for principals to indicate that they intend to exercise mechanism for principals to indicate that they intend to exercise
their access rights. Shared locks are provided for this case. A their access rights. Shared locks are provided for this case. A
shared lock allows multiple principals to receive a lock. Hence any shared lock allows multiple principals to receive a lock. Hence any
principal with appropriate access can get the lock. principal that has both access privileges and a valid lock can use
the locked resource.
With shared locks there are two trust sets that affect a resource. With shared locks there are two trust sets that affect a resource.
The first trust set is created by access permissions. Principals who The first trust set is created by access permissions. Principals who
are trusted, for example, may have permission to write to the are trusted, for example, may have permission to write to the
resource. Among those who have access permission to write to the resource. Among those who have access permission to write to the
resource, the set of principals who have taken out a shared lock also resource, the set of principals who have taken out a shared lock also
must trust each other, creating a (typically) smaller trust set must trust each other, creating a (typically) smaller trust set
within the access permission write set. within the access permission write set.
Starting with every possible principal on the Internet, in most Starting with every possible principal on the Internet, in most
skipping to change at page 15, line 42 skipping to change at page 23, line 7
decide they trust their collaborators will not overwrite their work decide they trust their collaborators will not overwrite their work
(the potential set of collaborators being the set of principals who (the potential set of collaborators being the set of principals who
have write permission) and use a shared lock, which informs their have write permission) and use a shared lock, which informs their
collaborators that a principal may be working on the resource. collaborators that a principal may be working on the resource.
The WebDAV extensions to HTTP do not need to provide all of the The WebDAV extensions to HTTP do not need to provide all of the
communications paths necessary for principals to coordinate their communications paths necessary for principals to coordinate their
activities. When using shared locks, principals may use any out of activities. When using shared locks, principals may use any out of
band communication channel to coordinate their work (e.g., face-to- band communication channel to coordinate their work (e.g., face-to-
face interaction, written notes, post-it notes on the screen, face interaction, written notes, post-it notes on the screen,
telephone conversation, Email, etc.) The intent of a shared lock is telephone conversation, email, etc.) The intent of a shared lock is
to let collaborators know who else may be working on a resource. to let collaborators know who else may be working on a resource.
Shared locks are included because experience from web distributed Shared locks are included because experience from web distributed
authoring systems has indicated that exclusive locks are often too authoring systems has indicated that exclusive locks are often too
rigid. An exclusive lock is used to enforce a particular editing rigid. An exclusive lock is used to enforce a particular editing
process: take out an exclusive lock, read the resource, perform process: take out an exclusive lock, read the resource, perform
edits, write the resource, release the lock. This editing process edits, write the resource, release the lock. This editing process
has the problem that locks are not always properly released, for has the problem that locks are not always properly released, for
example when a program crashes, or when a lock owner leaves without example when a program crashes, or when a lock creator leaves without
unlocking a resource. While both timeouts and administrative action unlocking a resource. While both timeouts (Section 6.6) and
can be used to remove an offending lock, neither mechanism may be administrative action can be used to remove an offending lock,
available when needed; the timeout may be long or the administrator neither mechanism may be available when needed; the timeout may be
may not be available. long or the administrator may not be available.
6.2. Required Support A successful request for a new shared lock MUST result in the
generation of a unique lock associated with the requesting principal.
Thus if five principals have taken out shared write locks on the same
resource there will be five locks and five lock tokens, one for each
principal.
A WebDAV compliant server is not required to support locking in any 6.3. Required Support
form. If the server does support locking it may choose to support
A WebDAV compliant resource is not required to support locking in any
form. If the resource does support locking it may choose to support
any combination of exclusive and shared locks for any access types. any combination of exclusive and shared locks for any access types.
The reason for this flexibility is that locking policy strikes to the The reason for this flexibility is that locking policy strikes to the
very heart of the resource management and versioning systems employed very heart of the resource management and versioning systems employed
by various storage repositories. These repositories require control by various storage repositories. These repositories require control
over what sort of locking will be made available. For example, some over what sort of locking will be made available. For example, some
repositories only support shared write locks while others only repositories only support shared write locks while others only
provide support for exclusive write locks while yet others use no provide support for exclusive write locks while yet others use no
locking at all. As each system is sufficiently different to merit locking at all. As each system is sufficiently different to merit
exclusion of certain locking features, this specification leaves exclusion of certain locking features, this specification leaves
locking as the sole axis of negotiation within WebDAV. locking as the sole axis of negotiation within WebDAV.
6.3. Lock Tokens 6.4. Lock Creator and Privileges
A lock token is a type of state token, represented as a URI, which
identifies a particular lock. A lock token is returned by every
successful LOCK operation in the lockdiscovery property in the
response body, and can also be found through lock discovery on a
resource.
Lock token URIs MUST be unique across all resources for all time.
This uniqueness constraint allows lock tokens to be submitted across
resources and servers without fear of confusion.
This specification provides a lock token URI scheme called
opaquelocktoken that meets the uniqueness requirements. However
resources are free to return any URI scheme so long as it meets the
uniqueness requirements.
Having a lock token provides no special access rights. Anyone can
find out anyone else's lock token by performing lock discovery.
Locks MUST be enforced based upon whatever authentication mechanism
is used by the server, not based on the secrecy of the token values.
6.4. opaquelocktoken Lock Token URI Scheme
The opaquelocktoken URI scheme is designed to be unique across all
resources for all time. Due to this uniqueness quality, a client may
submit an opaque lock token in an If header on a resource other than
the one that returned it.
All resources MUST recognize the opaquelocktoken scheme and, at
minimum, recognize that the lock token does not refer to an
outstanding lock on the resource.
In order to guarantee uniqueness across all resources for all time The creator of a lock has special privileges to use the lock to
the opaquelocktoken requires the use of the Universal Unique modify the resource. When a locked resource is modified, a server
Identifier (UUID) mechanism, as described in [ISO-11578]. MUST check that the authenticated principal matches the lock creator
(in addition to checking for valid lock token submission).
Opaquelocktoken generators, however, have a choice of how they create The server MAY allow privileged users other than the lock creator to
these tokens. They can either generate a new UUID for every lock destroy a lock (for example, the resource owner or an administrator).
token they create or they can create a single UUID and then add The 'unlock' privilege in [RFC3744] was defined to provide that
extension characters. If the second method is selected then the permission.
program generating the extensions MUST guarantee that the same
extension will never be used twice with the associated UUID.
OpaqueLockToken-URI = "opaquelocktoken:" UUID [Extension] ; The UUID There is no requirement for servers to accept LOCK requests from all
production is the string representation of a UUID, as defined in users or from anonymous users.
[ISO-11578]. Note that white space (LWS) is not allowed between
elements of this production.
Extension = path ; path is defined in section 3.2.1 of RFC 2068 Note that having a lock does not confer full privilege to modify the
[RFC2068] locked resource. Write access and other privileges MUST be enforced
through normal privilege or authentication mechanisms, not based on
the possible obscurity of lock token values.
6.4.1. Node Field Generation Without the IEEE 802 Address 6.5. Lock Tokens
UUIDs, as defined in [ISO-11578], contain a "node" field that A lock token is a type of state token which identifies a particular
contains one of the IEEE 802 addresses for the server machine. As lock. Each lock has exactly one unique lock token generated by the
noted in Section 17.8, there are several security risks associated server. Clients MUST NOT attempt to interpret lock tokens in any
with exposing a machine's IEEE 802 address. This section provides an way.
alternate mechanism for generating the "node" field of a UUID which
does not employ an IEEE 802 address. WebDAV servers MAY use this
algorithm for creating the node field when generating UUIDs. The
text in this section is originally from an Internet-Draft by Paul
Leach and Rich Salz, who are noted here to properly attribute their
work.
The ideal solution is to obtain a 47 bit cryptographic quality random Lock token URIs MUST be unique across all resources for all time.
number, and use it as the low 47 bits of the node ID, with the most This uniqueness constraint allows lock tokens to be submitted across
significant bit of the first octet of the node ID set to 1. This bit resources and servers without fear of confusion. Since lock tokens
is the unicast/multicast bit, which will never be set in IEEE 802 are unique, a client MAY submit a lock token in an If header on a
addresses obtained from network cards; hence, there can never be a resource other than the one that returned it.
conflict between UUIDs generated by machines with and without network
cards.
If a system does not have a primitive to generate cryptographic When a LOCK operation creates a new lock, the new lock token is
quality random numbers, then in most systems there are usually a returned in the Lock-Token response header defined in Section 10.5,
fairly large number of sources of randomness available from which one and also in the body of the response.
can be generated. Such sources are system specific, but often
include:
o the percent of memory in use Servers MAY make lock tokens publicly readable (e.g. in the DAV:
lockdiscovery property). One use case for making lock tokens
readable is so that a long-lived lock can be removed by the resource
owner (the client that obtained the lock might have crashed or
disconnected before cleaning up the lock). Except for the case of
using UNLOCK under user guidance, a client SHOULD NOT use a lock
token created by another client instance.
o the size of main memory in bytes This specification encourages servers to create UUIDs for lock
tokens, and to use the URI form defined by "A Universally Unique
Identifier (UUID) URN Namespace" ([RFC4122]). However servers are
free to use any URI (e.g. from another scheme) so long as it meets
the uniqueness requirements. For example, a valid lock token might
be constructed using the "opaquelocktoken" scheme defined in
Appendix C.
o the amount of free main memory in bytes Example: "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6"
o the size of the paging or swap file in bytes 6.6. Lock Timeout
o free bytes of paging or swap file A lock MAY have a limited lifetime. The lifetime is suggested by the
client when creating or refreshing the lock, but the server
ultimately chooses the timeout value. Timeout is measured in seconds
remaining until lock expiration.
o the total size of user virtual address space in bytes The timeout counter MUST be restarted if a refresh lock request is
successful (see Section 9.10.2). The timeout counter SHOULD NOT be
restarted at any other time.
o the total available user address space bytes If the timeout expires then the lock SHOULD be removed. In this case
the server SHOULD act as if an UNLOCK method was executed by the
server on the resource using the lock token of the timed-out lock,
performed with its override authority.
o the size of boot disk drive in bytes Servers are advised to pay close attention to the values submitted by
clients, as they will be indicative of the type of activity the
client intends to perform. For example, an applet running in a
browser may need to lock a resource, but because of the instability
of the environment within which the applet is running, the applet may
be turned off without warning. As a result, the applet is likely to
ask for a relatively small timeout value so that if the applet dies,
the lock can be quickly harvested. However, a document management
system is likely to ask for an extremely long timeout because its
user may be planning on going off-line.
o the free disk space on boot drive in bytes A client MUST NOT assume that just because the time-out has expired
the lock has immediately been removed.
o the current time Likewise, a client MUST NOT assume that just because the time-out has
not expired, the lock still exists. Clients MUST assume that locks
can arbitrarily disappear at any time, regardless of the value given
in the Timeout header. The Timeout header only indicates the
behavior of the server if extraordinary circumstances do not occur.
For example, a sufficiently privileged user may remove a lock at any
time or the system may crash in such a way that it loses the record
of the lock's existence.
o the amount of time since the system booted 6.7. Lock Capability Discovery
o the individual sizes of files in various system directories Since server lock support is optional, a client trying to lock a
resource on a server can either try the lock and hope for the best,
or perform some form of discovery to determine what lock capabilities
the server supports. This is known as lock capability discovery. A
client can determine what lock types the server supports by
retrieving the DAV:supportedlock property.
o the creation, last read, and modification times of files in Any DAV compliant resource that supports the LOCK method MUST support
various system directories the DAV:supportedlock property.
o the utilization factors of various system resources (heap, etc.) 6.8. Active Lock Discovery
o current mouse cursor position If another principal locks a resource that a principal wishes to
access, it is useful for the second principal to be able to find out
who the first principal is. For this purpose the DAV:lockdiscovery
property is provided. This property lists all outstanding locks,
describes their type, and MAY even provide the lock tokens.
o current caret position Any DAV compliant resource that supports the LOCK method MUST support
the DAV:lockdiscovery property.
o current number of running processes, threads 7. Write Lock
o handles or IDs of the desktop window and the active window This section describes the semantics specific to the write lock type.
The write lock is a specific instance of a lock type, and is the only
lock type described in this specification.
o the value of stack pointer of the caller An exclusive write lock protects a resource: it prevents changes by
any principal other than the lock creator and in any case where the
lock token is not submitted (e.g. by a client process other than the
one holding the lock).
o the process and thread ID of caller Clients MUST submit a lock-token they are authorized to use in any
request which modifies a write-locked resource. The list of
modifications covered by a write-lock include:
o various processor architecture specific performance counters 1. A change to any of the following aspects of any write-locked
(instructions executed, cache misses, TLB misses) resource:
(Note that it is precisely the above kinds of sources of randomness * any variant,
that are used to seed cryptographic quality random number generators
on systems without special hardware for their construction.)
In addition, items such as the computer's name and the name of the * any dead property,
operating system, while not strictly speaking random, will help
differentiate the results from those obtained by other systems.
The exact algorithm to generate a node ID using these data is system * any live property which is lockable (a live property is
specific, because both the data available and the functions to obtain lockable unless otherwise defined.)
them are often very system specific. However, assuming that one can
concatenate all the values from the randomness sources into a buffer,
and that a cryptographic hash function such as MD5 is available, then
any 6 bytes of the MD5 hash of the buffer, with the multicast bit
(the high bit of the first byte) set will be an appropriately random
node ID.
Other hash functions, such as SHA-1, can also be used. The only 2. For collections, any modification of an internal member URI. An
requirement is that the result be suitably random _ in the sense that internal member URI of a collection is considered to be modified
the outputs from a set uniformly distributed inputs are themselves if it is added, removed, or identifies a different resource.
uniformly distributed, and that a single bit change in the input can More discussion on write locks and collections is found in
be expected to cause half of the output bits to change. Section 7.4.
6.5. Lock Capability Discovery 3. A modification of the mapping of the root of the write lock,
either to another resource or to no resource (e.g. DELETE).
Since server lock support is optional, a client trying to lock a Of the methods defined in HTTP and WebDAV, PUT, POST, PROPPATCH,
resource on a server can either try the lock and hope for the best, LOCK, UNLOCK, MOVE, COPY (for the destination resource), DELETE, and
or perform some form of discovery to determine what lock capabilities MKCOL are affected by write locks. All other HTTP/WebDAV methods
the server supports. This is known as lock capability discovery. defined so far, GET in particular, function independently of a write
Lock capability discovery differs from discovery of supported access lock.
control types, since there may be access control types without
corresponding lock types. A client can determine what lock types the
server supports by retrieving the supportedlock property.
Any DAV compliant resource that supports the LOCK method MUST support The next few sections describe in more specific terms how write locks
the supportedlock property. interact with various operations.
6.6. Active Lock Discovery 7.1. Write Locks and Properties
If another principal locks a resource that a principal wishes to While those without a write lock may not alter a property on a
access, it is useful for the second principal to be able to find out resource it is still possible for the values of live properties to
who the first principal is. For this purpose the lockdiscovery change, even while locked, due to the requirements of their schemas.
property is provided. This property lists all outstanding locks,
describes their type, and where available, provides their lock token.
Any DAV compliant resource that supports the LOCK method MUST support Only dead properties and live properties defined as lockable are
the lockdiscovery property. guaranteed not to change while write locked.
6.7. Usage Considerations 7.2. Avoiding Lost Updates
Although the locking mechanisms specified here provide some help in Although the write locks provide some help in preventing lost
preventing lost updates, they cannot guarantee that updates will updates, they cannot guarantee that updates will never be lost.
never be lost. Consider the following scenario: Consider the following scenario:
Two clients A and B are interested in editing the resource ' Two clients A and B are interested in editing the resource
index.html'. Client A is an HTTP client rather than a WebDAV client, 'index.html'. Client A is an HTTP client rather than a WebDAV
and so does not know how to perform locking. client, and so does not know how to perform locking.
Client A doesn't lock the document, but does a GET and begins Client A doesn't lock the document, but does a GET and begins
editing. editing.
Client B does LOCK, performs a GET and begins editing. Client B does LOCK, performs a GET and begins editing.
Client B finishes editing, performs a PUT, then an UNLOCK. Client B finishes editing, performs a PUT, then an UNLOCK.
Client A performs a PUT, overwriting and losing all of B's changes. Client A performs a PUT, overwriting and losing all of B's changes.
skipping to change at page 21, line 5 skipping to change at page 29, line 5
they interact with a WebDAV server that supports locking. they interact with a WebDAV server that supports locking.
HTTP 1.1 clients can be good citizens, avoiding overwriting other HTTP 1.1 clients can be good citizens, avoiding overwriting other
clients' changes, by using entity tags in If-Match headers with any clients' changes, by using entity tags in If-Match headers with any
requests that would modify resources. requests that would modify resources.
Information managers may attempt to prevent overwrites by Information managers may attempt to prevent overwrites by
implementing client-side procedures requiring locking before implementing client-side procedures requiring locking before
modifying WebDAV resources. modifying WebDAV resources.
7. Write Lock 7.3. Write Locks and Unmapped URLs
This section describes the semantics specific to the write lock type. WebDAV provides the ability to send a LOCK request to an unmapped URL
The write lock is a specific instance of a lock type, and is the only in order to reserve the name for use. This is a simple way to avoid
lock type described in this specification. the lost-update problem on the creation of a new resource (another
way is to use If-None-Match header specified in Section 14.26 of
[RFC2616]). It has the side benefit of locking the new resource
immediately for use of the creator.
7.1. Methods Restricted by Write Locks Note that the lost-update problem is not an issue for collections
because MKCOL can only be used to create a collection, not to
overwrite an existing collection. When trying to lock a collection
upon creation, clients can attempt to increase the likelihood of
getting the lock by pipelining the MKCOL and LOCK requests together
(but because this doesn't convert two separate operations into one
atomic operation there's no guarantee this will work).
A write lock MUST prevent a principal without the lock from A successful lock request to an unmapped URL MUST result in the
successfully executing a PUT, POST, PROPPATCH, LOCK, UNLOCK, MOVE, creation of a locked (non-collection) resource with empty content.
DELETE, or MKCOL on the locked resource. All other current methods, Subsequently, a successful PUT request (with the correct lock token)
GET in particular, function independently of the lock. provides the content for the resource. Note that the LOCK request
has no mechanism for the client to provide Content-Type or Content-
Language, thus the server will use defaults or empty values and rely
on the subsequent PUT request for correct values.
Note, however, that as new methods are created it will be necessary A resource created with a LOCK is empty but otherwise behaves in
to specify how they interact with a write lock. every way as a normal resource. It behaves the same way as a
resource created by a PUT request with an empty body (and where a
Content-Type and Content-Language was not specified), followed by a
LOCK request to the same resource. Following from this model, a
locked empty resource:
7.2. Write Locks and Lock Tokens o Can be read, deleted, moved, copied, and in all ways behave as a
regular non-collection resource.
A successful request for an exclusive or shared write lock MUST o Appears as a member of its parent collection.
result in the generation of a unique lock token associated with the
requesting principal. Thus if five principals have a shared write
lock on the same resource there will be five lock tokens, one for
each principal.
7.3. Write Locks and Properties o SHOULD NOT disappear when its lock goes away (clients must
therefore be responsible for cleaning up their own mess, as with
any other operation or any non-empty resource)
While those without a write lock may not alter a property on a o MAY NOT have values for properties like DAV:getcontentlanguage
resource it is still possible for the values of live properties to which haven't been specified yet by the client.
change, even while locked, due to the requirements of their schemas.
Only dead properties and live properties defined to respect locks are
guaranteed not to change while write locked.
7.4. Write Locks and Null Resources o Can be updated (have content added) with a PUT request.
It is possible to assert a write lock on a null resource in order to o MUST NOT be converted into a collection. The server MUST fail a
lock the name. MKCOL request (as it would with a MKCOL request to any existing
non-collection resource).
A write locked null resource, referred to as a lock-null resource, o MUST have defined values for DAV:lockdiscovery and DAV:
MUST respond with a 404 (Not Found) or 405 (Method Not Allowed) to supportedlock properties.
any HTTP/1.1 or DAV methods except for PUT, MKCOL, OPTIONS, PROPFIND,
LOCK, and UNLOCK. A lock-null resource MUST appear as a member of
its parent collection. Additionally the lock-null resource MUST have
defined on it all mandatory DAV properties. Most of these
properties, such as all the get* properties, will have no value as a
lock-null resource does not support the GET method. Lock-Null
resources MUST have defined values for lockdiscovery and
supportedlock properties.
Until a method such as PUT or MKCOL is successfully executed on the o The response MUST indicate that a resource was created, by use of
lock-null resource the resource MUST stay in the lock-null state. the "201 Created" response code (a LOCK request to an existing
However, once a PUT or MKCOL is successfully executed on a lock-null resource instead will result in 200 OK). The body must still
resource the resource ceases to be in the lock-null state. include the DAV:lockdiscovery property, as with a LOCK request to
an existing resource.
If the resource is unlocked, for any reason, without a PUT, MKCOL, or The client is expected to update the locked empty resource shortly
similar method having been successfully executed upon it then the after locking it, using PUT and possibly PROPPATCH.
resource MUST return to the null state.
7.5. Write Locks and Collections Alternatively and for backwards compatibility to [RFC2518], servers
MAY implement Lock-Null Resources (LNRs) instead (see definition in
Appendix D). Clients can easily interoperate both with servers that
support the old model LNRs and the recommended model of "locked empty
resources" by only attempting PUT after a LOCK to an unmapped URL,
not MKCOL or GET, and by not relying on specific properties of LNRs.
A write lock on a collection, whether created by a "Depth: 0" or 7.4. Write Locks and Collections
"Depth: infinity" lock request, prevents the addition or removal of
member URIs of the collection by non-lock owners. As a consequence,
when a principal issues a PUT or POST request to create a new
resource under a URI which needs to be an internal member of a write
locked collection to maintain HTTP namespace consistency, or issues a
DELETE to remove a resource which has a URI which is an existing
internal member URI of a write locked collection, this request MUST
fail if the principal does not have a write lock on the collection.
However, if a write lock request is issued to a collection containing There are two kinds of collection write locks. A depth-0 write lock
member URIs identifying resources that are currently locked in a on a collection protects the collection properties plus the internal
manner which conflicts with the write lock, the request MUST fail member URLs of that one collection, while not protecting the content
with a 423 (Locked) status code. or properties of member resources (if the collection itself has any
entity bodies, those are also protected). A depth-infinity write
lock on a collection provides the same protection on that collection
and also provides write lock protection on every member resource.
If a lock owner causes the URI of a resource to be added as an Expressed otherwise, a write lock protects any request that would
internal member URI of a locked collection then the new resource MUST create a new resource in a write locked collection, any request that
be automatically added to the lock. This is the only mechanism that would remove an internal member URL of a write locked collection, and
allows a resource to be added to a write lock. Thus, for example, if any request that would change the segment name of any internal
the collection /a/b/ is write locked and the resource /c is moved to member.
/a/b/c then resource /a/b/c will be added to the write lock.
7.6. Write Locks and the If Request Header Thus, a collection write lock protects all the following actions:
If a user agent is not required to have knowledge about a lock when o DELETE a collection's direct internal member,
requesting an operation on a locked resource, the following scenario
might occur. Program A, run by User A, takes out a write lock on a o MOVE an internal member out of the collection,
resource. Program B, also run by User A, has no knowledge of the
lock taken out by Program A, yet performs a PUT to the locked o MOVE an internal member into the collection,
resource. In this scenario, the PUT succeeds because locks are
associated with a principal, not a program, and thus program B, o MOVE to rename an internal member within a collection,
because it is acting with principal A's credential, is allowed to o COPY an internal member into a collection, and
perform the PUT. However, had program B known about the lock, it
would not have overwritten the resource, preferring instead to o PUT or MKCOL request which would create a new internal member.
present a dialog box describing the conflict to the user. Due to
The collection's lock token is required in addition to the lock token
on the internal member itself, if it is locked separately.
In addition, a depth-infinity lock affects all write operations to
all members of the locked collection. With a depth-infinity lock,
the resource identified by the root of the lock is directly locked,
and all its members are indirectly locked.
o Any new resource added as a descendent of a depth-infinity locked
collection becomes indirectly locked.
o Any indirectly locked resource moved out of the locked collection
into an unlocked collection is thereafter unlocked.
o Any indirectly locked resource moved out of a locked source
collection into a depth-infinity locked target collection remains
indirectly locked but is now protected by the lock on the target
collection (the target collection's lock token will thereafter be
required to make further changes).
If a depth-infinity write LOCK request is issued to a collection
containing member URLs identifying resources that are currently
locked in a manner which conflicts with the new lock (see Section 6.1
point 3), the request MUST fail with a 423 (Locked) status code, and
the response SHOULD contain the 'no-conflicting-lock' precondition.
If a lock request causes the URL of a resource to be added as an
internal member URL of a depth-infinity locked collection then the
new resource MUST be automatically protected by the lock. For
example, if the collection /a/b/ is write locked and the resource /c
is moved to /a/b/c then resource /a/b/c will be added to the write
lock.
7.5. Write Locks and the If Request Header
A user agent has to demonstrate knowledge of a lock when requesting
an operation on a locked resource. Otherwise, the following scenario
might occur. In the scenario, program A, run by User A, takes out a
write lock on a resource. Program B, also run by User A, has no
knowledge of the lock taken out by program A, yet performs a PUT to
the locked resource. In this scenario, the PUT succeeds because
locks are associated with a principal, not a program, and thus
program B, because it is acting with principal A's credential, is
allowed to perform the PUT. However, had program B known about the
lock, it would not have overwritten the resource, preferring instead
to present a dialog box describing the conflict to the user. Due to
this scenario, a mechanism is needed to prevent different programs this scenario, a mechanism is needed to prevent different programs
from accidentally ignoring locks taken out by other programs with the from accidentally ignoring locks taken out by other programs with the
same authorization. same authorization.
In order to prevent these collisions a lock token MUST be submitted In order to prevent these collisions a lock token MUST be submitted
by an authorized principal in the If header for all locked resources by an authorized principal for all locked resources that a method may
that a method may interact with or the method MUST fail. For change or the method MUST fail. A lock token is submitted when it
example, if a resource is to be moved and both the source and appears in an If header. For example, if a resource is to be moved
destination are locked then two lock tokens must be submitted, one and both the source and destination are locked then two lock tokens
for the source and the other for the destination. must be submitted in the If header, one for the source and the other
for the destination.
7.6.1. Example - Write Lock 7.5.1. Example - Write Lock and COPY
>>Request >>Request
COPY /~fielding/index.html HTTP/1.1 COPY /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example.com/users/f/fielding/index.html
If: <http://www.ics.uci.edu/users/f/fielding/index.html> If: <http://www.example.com/users/f/fielding/index.html>
(<opaquelocktoken:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>) (<urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>)
&#9225;
>>Response >>Response
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
In this example, even though both the source and destination are In this example, even though both the source and destination are
locked, only one lock token must be submitted, for the lock on the locked, only one lock token must be submitted, for the lock on the
destination. This is because the source resource is not modified by destination. This is because the source resource is not modified by
a COPY, and hence unaffected by the write lock. In this example, a COPY, and hence unaffected by the write lock. In this example,
user agent authentication has previously occurred via a mechanism user agent authentication has previously occurred via a mechanism
outside the scope of the HTTP protocol, in the underlying transport outside the scope of the HTTP protocol, in the underlying transport
layer. layer.
7.7. Write Locks and COPY/MOVE 7.5.2. Example - Deleting a Member of a Locked Collection
Consider a collection "/locked" with an exclusive, depth-infinity
write lock, and an attempt to delete an internal member "/locked/
member":
>>Request
DELETE /locked/member HTTP/1.1
Host: example.com
>>Response
HTTP/1.1 423 Locked
Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:error xmlns:D="DAV:">
<D:lock-token-submitted>
<D:href>/locked/</D:href>
</D:lock-token-submitted>
</D:error>
Thus the client would need to submit the lock token with the request
to make it succeed. To do that, various forms of the If header (see
Section 10.4) could be used.
"No-Tag-List" format:
If: (<urn:uuid:150852e2-3847-42d5-8cbe-0f4f296f26cf>)
"Tagged-List" format, for "http://example.com/locked/":
If: <http://example.com/locked/>
(<urn:uuid:150852e2-3847-42d5-8cbe-0f4f296f26cf>)
"Tagged-List" format, for "http://example.com/locked/member":
If: <http://example.com/locked/member>
(<urn:uuid:150852e2-3847-42d5-8cbe-0f4f296f26cf>)
Note that for the purpose of submitting the lock token the actual
form doesn't matter; what's relevant is that the lock token appears
in the If header, and that the If header itself evaluates to true.
7.6. Write Locks and COPY/MOVE
A COPY method invocation MUST NOT duplicate any write locks active on A COPY method invocation MUST NOT duplicate any write locks active on
the source. However, as previously noted, if the COPY copies the the source. However, as previously noted, if the COPY copies the
resource into a collection that is locked with "Depth: infinity", resource into a collection that is locked with a depth-infinity lock,
then the resource will be added to the lock. then the resource will be added to the lock.
A successful MOVE request on a write locked resource MUST NOT move A successful MOVE request on a write locked resource MUST NOT move
the write lock with the resource. However, the resource is subject the write lock with the resource. However, if there is an existing
to being added to an existing lock at the destination, as specified lock at the destination, the server MUST add the moved resource to
in Section 7.5. For example, if the MOVE makes the resource a child the destination lock scope. For example, if the MOVE makes the
of a collection that is locked with "Depth: infinity", then the resource a child of a collection that has a depth-infinity lock, then
resource will be added to that collection's lock. Additionally, if a the resource will be added to that collection's lock. Additionally,
resource locked with "Depth: infinity" is moved to a destination that if a resource with a depth-infinity lock is moved to a destination
is within the scope of the same lock (e.g., within the namespace tree that is within the scope of the same lock (e.g., within the URL
covered by the lock), the moved resource will again be a added to the namespace tree covered by the lock), the moved resource will again be
lock. In both these examples, as specified in Section 7.6, an If a added to the lock. In both these examples, as specified in
header must be submitted containing a lock token for both the source Section 7.5, an If header must be submitted containing a lock token
and destination. for both the source and destination.
7.8. Refreshing Write Locks 7.7. Refreshing Write Locks
A client MUST NOT submit the same write lock request twice. Note A client MUST NOT submit the same write lock request twice. Note
that a client is always aware it is resubmitting the same lock that a client is always aware it is resubmitting the same lock
request because it must include the lock token in the If header in request because it must include the lock token in the If header in
order to make the request for a resource that is already locked. order to make the request for a resource that is already locked.
However, a client may submit a LOCK method with an If header but However, a client may submit a LOCK request with an If header but
without a body. This form of LOCK MUST only be used to "refresh" a without a body. A server receiving a LOCK request with no body MUST
lock. Meaning, at minimum, that any timers associated with the lock NOT create a new lock -- this form of the LOCK request is only to be
MUST be re-set. used to "refresh" an existing lock (meaning, at minimum, that any
timers associated with the lock MUST be re-set).
A server may return a Timeout header with a lock refresh that is Clients may submit Timeout headers of arbitrary value with their lock
different than the Timeout header returned when the lock was refresh requests. Servers, as always, may ignore Timeout headers
originally requested. Additionally clients may submit Timeout submitted by the client, and a server MAY refresh a lock with a
headers of arbitrary value with their lock refresh requests. timeout period that is different than the previous timeout period
Servers, as always, may ignore Timeout headers submitted by the used for the lock, provided it advertises the new value in the LOCK
client. refresh response.
If an error is received in response to a refresh LOCK request the If an error is received in response to a refresh LOCK request the
client SHOULD assume that the lock was not refreshed. client MUST NOT assume that the lock was refreshed.
8. HTTP Methods for Distributed Authoring 8. General Request and Response Handling
The following new HTTP methods use XML as a request and response 8.1. Precedence in Error Handling
format. All DAV compliant clients and resources MUST use XML parsers
that are compliant with [REC-XML]. All XML used in either requests
or responses MUST be, at minimum, well formed. If a server receives
ill-formed XML in a request it MUST reject the entire request with a
400 (Bad Request). If a client receives ill-formed XML in a response
then it MUST NOT assume anything about the outcome of the executed
method and SHOULD treat the server as malfunctioning.
8.1. PROPFIND Servers MUST return authorization errors in preference to other
errors. This avoids leaking information about protected resources
(e.g. a client that finds that a hidden resource exists by seeing a
423 Locked response to an anonymous request to the resource).
8.2. Use of XML
In HTTP/1.1, method parameter information was exclusively encoded in
HTTP headers. Unlike HTTP/1.1, WebDAV encodes method parameter
information either in an XML ([REC-XML]) request entity body, or in
an HTTP header. The use of XML to encode method parameters was
motivated by the ability to add extra XML elements to existing
structures, providing extensibility; and by XML's ability to encode
information in ISO 10646 character sets, providing
internationalization support.
In addition to encoding method parameters, XML is used in WebDAV to
encode the responses from methods, providing the extensibility and
internationalization advantages of XML for method output, as well as
input.
When XML is used for a request or response body, the Content-Type
type SHOULD be application/xml. Implementations MUST accept both
text/xml and application/xml in request and response bodies. Use of
text/xml is deprecated.
All DAV compliant clients and resources MUST use XML parsers that are
compliant with [REC-XML] and [REC-XML-NAMES]. All XML used in either
requests or responses MUST be, at minimum, well formed and use
namespaces correctly. If a server receives XML that is not well-
formed then the server MUST reject the entire request with a 400 (Bad
Request). If a client receives XML that is not well-formed in a
response then the client MUST NOT assume anything about the outcome
of the executed method and SHOULD treat the server as malfunctioning.
Note that processing XML submitted by an untrusted source may cause
risks connected to privacy, security, and service quality (see
Section 20). Servers MAY reject questionable requests (even though
they consist of well-formed XML), for instance with a 400 (Bad
Request) status code and an optional response body explaining the
problem.
8.3. URL Handling
URLs appear in many places in requests and responses.
Interoperability experience with [RFC2518] showed that many clients
parsing Multi-Status responses did not fully implement the full
Reference Resolution defined in Section 5 of [RFC3986]. Thus,
servers in particular need to be careful in handling URLs in
responses, to ensure that clients have enough context to be able to
interpret all the URLs. The rules in this section apply not only to
resource URLs in the 'href' element in Multi-Status responses, but
also to the Destination and If header resource URLs.
The sender has a choice between two approaches: using a relative
reference, which is resolved against the Request-URI, or a full URI.
A server MUST ensure that every 'href' value within a Multi-Status
response uses the same format.
WebDAV only uses one form of relative reference in its extensions,
the absolute path.
Simple-ref = absolute-URI | ( path-absolute [ "?" query ] )
The absolute-URI, path-absolute and query productions are defined in
Section 4.3, 3.3 and 3.4 of [RFC3986].
Within Simple-ref productions, senders MUST NOT:
o use dot-segments ("." or ".."), or
o have prefixes that do not match the Request-URI (using the
comparison rules defined in Section 3.2.3 of [RFC2616]).
Identifiers for collections SHOULD end in a '/' character.
8.3.1. Example - Correct URL Handling
Consider the collection http://example.com/sample/ with the internal
member URL http://example.com/sample/a%20test and the PROPFIND
request below:
>>Request:
PROPFIND /sample/ HTTP/1.1
Host: example.com
Depth: 1
In this case, the server should return two 'href' elements containing
either
o 'http://example.com/sample/' and
'http://example.com/sample/a%20test', or
o '/sample/' and '/sample/a%20test'
Note that even though the server may be storing the member resource
internally as 'a test', it has to be percent-encoded when used inside
a URI reference (see Section 2.1 of [RFC3986]). Also note that a
legal URI may still contain characters that need to be escaped within
XML character data, such as the ampersand character.
8.4. Required Bodies in Requests
Some of these new methods do not define bodies. Servers MUST examine
all requests for a body, even when a body was not expected. In cases
where a request body is present but would be ignored by a server, the
server MUST reject the request with 415 (Unsupported Media Type).
This informs the client (which may have been attempting to use an
extension) that the body could not be processed as the client
intended.
8.5. HTTP Headers for use in WebDAV
HTTP defines many headers that can be used in WebDAV requests and
responses. Not all of these are appropriate in all situations and
some interactions may be undefined. Note that HTTP 1.1 requires the
Date header in all responses if possible (see Section 14.18,
[RFC2616]).
The server MUST do authorization checks before checking any HTTP
conditional header.
8.6. ETag
HTTP 1.1 recommends the use of ETags rather than modification dates,
for cache-control, and there are even stronger reasons to prefer
ETags for authoring. Correct use of ETags is even more important in
a distributed authoring environment, because ETags are necessary
along with locks to avoid the lost-update problem. A client might
fail to renew a lock, for example when the lock times out and the
client is accidentally offline or in the middle of a long upload.
When a client fails to renew the lock, it's quite possible the
resource can still be relocked and the user can go on editing, as
long as no changes were made in the meantime. ETags are required for
the client to be able to distinguish this case. Otherwise, the
client is forced to ask the user whether to overwrite the resource on
the server without even being able to tell the user whether it has
changed. Timestamps do not solve this problem nearly as well as
ETags.
Strong ETags are much more useful for authoring use cases than weak
ETags (see Section 13.3.3 of [RFC2616]). Semantic equivalence can be
a useful concept but that depends on the document type and the
application type, and interoperability might require some agreement
or standard outside the scope of this specification and HTTP. Note
also that weak ETags have certain restrictions in HTTP, e.g. these
cannot be used in If-Match headers.
Note that the meaning of an ETag in a PUT response is not clearly
defined either in this document or in RFC2616 (i.e., whether the ETag
means that the resource is octet-for-octet equivalent to the body of
the PUT request, or whether the server could have made minor changes
in the formatting or content of the document upon storage). This is
an HTTP issue, not purely a WebDAV issue.
Because clients may be forced to prompt users or throw away changed
content if the ETag changes, a WebDAV server SHOULD NOT change the
ETag (or the Last-Modified time) for a resource that has an unchanged
body and location. The ETag represents the state of the body or
contents of the resource. There is no similar way to tell if
properties have changed.
8.7. Including Error Response Bodies
HTTP and WebDAV did not use the bodies of most error responses for
machine-parsable information until the specification for Versioning
Extensions to WebDAV introduced a mechanism to include more specific
information in the body of an error response (Section 1.6 of
[RFC3253]). The error body mechanism is appropriate to use with any
error response that may take a body but does not already have a body
defined. The mechanism is particularly appropriate when a status
code can mean many things (for example, 400 Bad Request can mean
required headers are missing, headers are incorrectly formatted, or
much more). This error body mechanism is covered in Section 16.
8.8. Impact of Namespace Operations on Cache Validators
Note that the HTTP response headers "Etag" and "Last-Modified" (see
[RFC2616], Sections 14.19 and 14.29) are defined per URL (not per
resource), and are used by clients for caching. Therefore servers
must ensure that executing any operation that affects the URL
namespace (such as COPY, MOVE, DELETE, PUT or MKCOL) does preserve
their semantics, in particular:
o For any given URL, the "Last-Modified" value MUST increment every
time the representation returned upon GET changes (within the
limits of timestamp resolution).
o For any given URL, an "ETag" value MUST NOT be re-used for
different representations returned by GET.
In practice this means that servers
o might have to increment "Last-Modified" timestamps for every
resource inside the destination namespace of a namespace operation
unless it can do so more selectively, and
o similarily, might have to re-assign "ETag" values for these
resources (unless the server allocates entity tags in a way so
that they are unique across the whole URL namespace managed by the
server).
Note that these considerations also apply to specific use cases, such
as using PUT to create a new resource at a URL that has been mapped
before, but has been deleted since then.
Finally, WebDAV properties (such as DAV:getetag and DAV:
getlastmodified) that inherit their semantics from HTTP headers must
behave accordingly.
9. HTTP Methods for Distributed Authoring
9.1. PROPFIND Method
The PROPFIND method retrieves properties defined on the resource The PROPFIND method retrieves properties defined on the resource
identified by the Request-URI, if the resource does not have any identified by the Request-URI, if the resource does not have any
internal members, or on the resource identified by the Request-URI internal members, or on the resource identified by the Request-URI
and potentially its member resources, if the resource is a collection and potentially its member resources, if the resource is a collection
that has internal member URIs. All DAV compliant resources MUST that has internal member URLs. All DAV compliant resources MUST
support the PROPFIND method and the propfind XML element (section support the PROPFIND method and the propfind XML element
12.14) along with all XML elements defined for use with that element. (Section 14.20) along with all XML elements defined for use with that
element.
A client may submit a Depth header with a value of "0", "1", or A client MUST submit a Depth header with a value of "0", "1", or
"infinity" with a PROPFIND on a collection resource with internal "infinity" with a PROPFIND request. Servers MUST support "0" and "1"
member URIs. DAV compliant servers MUST support the "0", "1" and depth requests on WebDAV-compliant resources and SHOULD support
"infinity" behaviors. By default, the PROPFIND method without a "infinity" requests. In practice, support for infinite depth
Depth header MUST act as if a "Depth: infinity" header was included. requests MAY be disabled, due to the performance and security
concerns associated with this behavior. Since clients weren't
required to include the Depth header in [RFC2518], servers SHOULD
treat such a request as if a "Depth: infinity" header was included.
A client may submit a propfind XML element in the body of the request A client may submit a 'propfind' XML element in the body of the
method describing what information is being requested. It is request method describing what information is being requested. It is
possible to request particular property values, all property values, possible to:
or a list of the names of the resource's properties. A client may
choose not to submit a request body. An empty PROPFIND request body o Request particular property values, by naming the properties
MUST be treated as a request for the names and values of all desired within the 'prop' element (the ordering of properties in
properties. here MAY be ignored by server),
o Request property values for those properties defined in this
specification (at a minimum) plus dead properties, by using the
'allprop' element (the 'include' element can be used with
'allprop' to instruct the server to also include additional live
properties that may not have been returned otherwise),
o Request a list of names of all the properties defined on the
resource, by using the 'propname' element.
A client may choose not to submit a request body. An empty PROPFIND
request body MUST be treated as if it were an 'allprop' request.
Note that 'allprop' does not return values for all live properties.
WebDAV servers increasingly have expensively-calculated or lengthy
properties (see [RFC3253] and [RFC3744]) and do not return all
properties already. Instead, WebDAV clients can use propname
requests to discover what live properties exist, and request named
properties when retrieving values. For a live property defined
elsewhere, that definition can specify whether that live property
would be returned in 'allprop' requests or not.
All servers MUST support returning a response of content type text/ All servers MUST support returning a response of content type text/
xml or application/xml that contains a multistatus XML element that xml or application/xml that contains a multistatus XML element that
describes the results of the attempts to retrieve the various describes the results of the attempts to retrieve the various
properties. properties.
If there is an error retrieving a property then a proper error result If there is an error retrieving a property then a proper error result
MUST be included in the response. A request to retrieve the value of MUST be included in the response. A request to retrieve the value of
a property which does not exist is an error and MUST be noted, if the a property which does not exist is an error and MUST be noted with a
response uses a multistatus XML element, with a response XML element 'response' XML element which contains a 404 (Not Found) status value.
which contains a 404 (Not Found) status value.
Consequently, the multistatus XML element for a collection resource Consequently, the 'multistatus' XML element for a collection resource
with member URIs MUST include a response XML element for each member MUST include a 'response' XML element for each member URL of the
URI of the collection, to whatever depth was requested. Each collection, to whatever depth was requested. It SHOULD NOT include
response XML element MUST contain an href XML element that gives the any 'response' elements for resources that are not WebDAV-compliant.
URI of the resource on which the properties in the prop XML element Each 'response' element MUST contain an 'href' element that contains
are defined. Results for a PROPFIND on a collection resource with the URL of the resource on which the properties in the prop XML
internal member URIs are returned as a flat list whose order of element are defined. Results for a PROPFIND on a collection resource
entries is not significant. are returned as a flat list whose order of entries is not
significant. Note that a resource may have only one value for a
property of a given name, so the property may only show up once in
PROPFIND responses.
In the case of allprop and propname, if a principal does not have the Properties may be subject to access control. In the case of
'allprop' and 'propname' requests, if a principal does not have the
right to know whether a particular property exists then the property right to know whether a particular property exists then the property
should be silently excluded from the response. MAY be silently excluded from the response.
The results of this method SHOULD NOT be cached. Some PROPFIND results MAY be cached, with care as there is no cache
validation mechanism for most properties. This method is both safe
and idempotent (see Section 9.1 of [RFC2616]).
8.1.1. Example - Retrieving Named Properties 9.1.1. PROPFIND Status Codes
>>Request This section, as with similar sections for other methods, provides
some guidance on error codes and preconditions or postconditions
(defined in Section 16) that might be particularly useful with
PROPFIND.
PROPFIND /file HTTP/1.1 403 Forbidden - A server MAY reject PROPFIND requests on collections
Host: www.foo.bar with depth header of "Infinity", in which case it SHOULD use this
Content-type: text/xml; charset="utf-8" error with the precondition code 'propfind-finite-depth' inside the
Content-Length: xxxx error body.
<?xml version="1.0" encoding="utf-8" ?> 9.1.2. Status Codes for Use in 'propstat' Element
<D:propfind xmlns:D="DAV:">
<D:prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox/>
<R:author/>
<R:DingALing/>
<R:Random/>
</D:prop>
</D:propfind>
>>Response In PROPFIND responses, information about individual properties is
returned inside 'propstat' elements (see Section 14.22), each
containing an individual 'status' element containing information
about the properties appearing in it. The list below summarizes the
most common status codes used inside 'propstat', however clients
should be prepared to handle other 2/3/4/5xx series status codes as
well.
HTTP/1.1 207 Multi-Status 200 OK - A property exists and/or its value is successfully returned.
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> 401 Unauthorized - The property cannot be viewed without appropriate
<D:multistatus xmlns:D="DAV:"> authorization.
<D:response>
<D:href>http://www.foo.bar/file</D:href>
<D:propstat>
<D:prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox>
<R:BoxType>Box type A</R:BoxType>
</R:bigbox>
<R:author>
<R:Name>J.J. Johnson</R:Name>
</R:author>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
<D:propstat>
<D:prop><R:DingALing/><R:Random/></D:prop>
<D:status>HTTP/1.1 403 Forbidden</D:status>
<D:responsedescription> The user does not have access to
the DingALing property.
</D:responsedescription>
</D:propstat>
</D:response>
<D:responsedescription> There has been an access violation error.
</D:responsedescription>
</D:multistatus>
In this example, PROPFIND is executed on a non-collection resource 403 Forbidden - The property cannot be viewed regardless of
http://www.foo.bar/file. The propfind XML element specifies the name authentication.
of four properties whose values are being requested. In this case
only two properties were returned, since the principal issuing the
request did not have sufficient access rights to see the third and
fourth properties.
8.1.2. Example - Using allprop to Retrieve All Properties 404 Not Found - The property does not exist.
9.1.3. Example - Retrieving Named Properties
>>Request >>Request
PROPFIND /container/ HTTP/1.1 PROPFIND /file HTTP/1.1
Host: www.foo.bar Host: www.example.com
Depth: 1 Content-type: application/xml; charset="utf-8"
Content-Type: text/xml; charset="utf-8" Content-Length: xxxx
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:"> <D:propfind xmlns:D="DAV:">
<D:allprop/> <D:prop xmlns:R="http://ns.example.com/boxschema/">
</D:propfind> <R:bigbox/>
<R:author/>
<R:DingALing/>
<R:Random/>
</D:prop>
</D:propfind>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"> <D:multistatus xmlns:D="DAV:">
<D:response> <D:response xmlns:R="http://ns.example.com/boxschema/">
<D:href>http://www.foo.bar/container/</D:href> <D:href>http://www.example.com/file</D:href>
<D:propstat> <D:propstat>
<D:prop xmlns:R="http://www.foo.bar/boxschema/"> <D:prop>
<R:bigbox> <R:bigbox>
<R:BoxType>Box type A</R:BoxType> <R:BoxType>Box type A</R:BoxType>
</R:bigbox> </R:bigbox>
<R:author> <R:author>
<R:Name>Hadrian</R:Name> <R:Name>J.J. Johnson</R:Name>
</R:author> </R:author>
<D:creationdate> </D:prop>
1997-12-01T17:42:21-08:00 <D:status>HTTP/1.1 200 OK</D:status>
</D:creationdate> </D:propstat>
<D:displayname> <D:propstat>
Example collection <D:prop><R:DingALing/><R:Random/></D:prop>
</D:displayname> <D:status>HTTP/1.1 403 Forbidden</D:status>
<D:resourcetype><D:collection/></D:resourcetype> <D:responsedescription> The user does not have access to the
<D:supportedlock> DingALing property.
<D:lockentry> </D:responsedescription>
<D:lockscope><D:exclusive/></D:lockscope> </D:propstat>
<D:locktype><D:write/></D:locktype> </D:response>
</D:lockentry> <D:responsedescription> There has been an access violation error.
<D:lockentry> </D:responsedescription>
<D:lockscope><D:shared/></D:lockscope> </D:multistatus>
<D:locktype><D:write/></D:locktype>
</D:lockentry> In this example, PROPFIND is executed on a non-collection resource
</D:supportedlock> http://www.example.com/file. The propfind XML element specifies the
</D:prop> name of four properties whose values are being requested. In this
<D:status>HTTP/1.1 200 OK</D:status> case only two properties were returned, since the principal issuing
</D:propstat> the request did not have sufficient access rights to see the third
</D:response> and fourth properties.
<D:response>
<D:href>http://www.foo.bar/container/front.html</D:href>
<D:propstat>
<D:prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox>
<R:BoxType>Box type B</R:BoxType>
</R:bigbox>
<D:creationdate>
1997-12-01T18:27:21-08:00
</D:creationdate>
<D:displayname>
Example HTML resource
</D:displayname>
<D:getcontentlength>
4525
</D:getcontentlength>
<D:getcontenttype>
text/html
</D:getcontenttype>
<D:getetag>
zzyzx
</D:getetag>
<D:getlastmodified>
Monday, 12-Jan-98 09:25:56 GMT
</D:getlastmodified>
<D:resourcetype/>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
In this example, PROPFIND was invoked on the resource 9.1.4. Example - Using 'propname' to Retrieve All Property Names
http://www.foo.bar/container/ with a Depth header of 1, meaning the
request applies to the resource and its children, and a propfind XML
element containing the allprop XML element, meaning the request
should return the name and value of all properties defined on each
resource.
The resource http://www.foo.bar/container/ has six properties defined >>Request
on it:
http://www.foo.bar/boxschema/bigbox, PROPFIND /container/ HTTP/1.1
http://www.foo.bar/boxschema/author, DAV:creationdate, DAV: Host: www.example.com
displayname, DAV:resourcetype, and DAV:supportedlock. Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
The last four properties are WebDAV-specific, defined in Section 13. <?xml version="1.0" encoding="utf-8" ?>
Since GET is not supported on this resource, the get* properties <propfind xmlns="DAV:">
(e.g., getcontentlength) are not defined on this resource. The DAV- <propname/>
specific properties assert that "container" was created on December </propfind>
1, 1997, at 5:42:21PM, in a time zone 8 hours west of GMT
(creationdate), has a name of "Example collection" (displayname), a
collection resource type (resourcetype), and supports exclusive write
and shared write locks (supportedlock).
The resource http://www.foo.bar/container/front.html has nine >>Response
properties defined on it:
http://www.foo.bar/boxschema/bigbox (another instance of the "bigbox" HTTP/1.1 207 Multi-Status
property type), DAV:creationdate, DAV:displayname, DAV: Content-Type: application/xml; charset="utf-8"
getcontentlength, DAV:getcontenttype, DAV:getetag, DAV: Content-Length: xxxx
getlastmodified, DAV:resourcetype, and DAV:supportedlock.
The DAV-specific properties assert that "front.html" was created on <?xml version="1.0" encoding="utf-8" ?>
December 1, 1997, at 6:27:21PM, in a time zone 8 hours west of GMT <multistatus xmlns="DAV:">
(creationdate), has a name of "Example HTML resource" (displayname), <response>
a content length of 4525 bytes (getcontentlength), a MIME type of <href>http://www.example.com/container/</href>
"text/html" (getcontenttype), an entity tag of "zzyzx" (getetag), was <propstat>
last modified on Monday, January 12, 1998, at 09:25:56 GMT <prop xmlns:R="http://ns.example.com/boxschema/">
(getlastmodified), has an empty resource type, meaning that it is not <R:bigbox/>
a collection (resourcetype), and supports both exclusive write and <R:author/>
shared write locks (supportedlock). <creationdate/>
<displayname/>
<resourcetype/>
<supportedlock/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
<response>
<href>http://www.example.com/container/front.html</href>
<propstat>
<prop xmlns:R="http://ns.example.com/boxschema/">
<R:bigbox/>
<creationdate/>
<displayname/>
<getcontentlength/>
<getcontenttype/>
<getetag/>
<getlastmodified/>
<resourcetype/>
<supportedlock/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
</multistatus>
8.1.3. Example - Using propname to Retrieve all Property Names In this example, PROPFIND is invoked on the collection resource
http://www.example.com/container/, with a propfind XML element
containing the propname XML element, meaning the name of all
properties should be returned. Since no Depth header is present, it
assumes its default value of "infinity", meaning the name of the
properties on the collection and all its descendents should be
returned.
Consistent with the previous example, resource
http://www.example.com/container/ has six properties defined on it:
bigbox and author in the "http://ns.example.com/boxschema/"
namespace, and creationdate, displayname, resourcetype, and
supportedlock in the "DAV:" namespace.
The resource http://www.example.com/container/index.html, a member of
the "container" collection, has nine properties defined on it, bigbox
in the "http://ns.example.com/boxschema/" namespace and,
creationdate, displayname, getcontentlength, getcontenttype, getetag,
getlastmodified, resourcetype, and supportedlock in the "DAV:"
namespace.
This example also demonstrates the use of XML namespace scoping and
the default namespace. Since the "xmlns" attribute does not contain
a prefix, the namespace applies by default to all enclosed elements.
Hence, all elements which do not explicitly state the namespace to
which they belong are members of the "DAV:" namespace.
9.1.5. Example - Using So-called 'allprop'
Note that 'allprop', despite its name which remains for backward-
compatibility, does not return every property, but only dead
properties and the live properties defined in this specification.
>>Request >>Request
PROPFIND /container/ HTTP/1.1 PROPFIND /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Content-Type: text/xml; charset="utf-8" Depth: 1
Content-Length: xxxx Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<propfind xmlns="DAV:"> <D:propfind xmlns:D="DAV:">
<propname/> <D:allprop/>
</propfind> </D:propfind>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<multistatus xmlns="DAV:"> <D:multistatus xmlns:D="DAV:">
<response> <D:response>
<href>http://www.foo.bar/container/</href> <D:href>/container/</D:href>
<propstat> <D:propstat>
<prop xmlns:R="http://www.foo.bar/boxschema/"> <D:prop xmlns:R="http://ns.example.com/boxschema/">
<R:bigbox/> <R:bigbox><R:BoxType>Box type A</R:BoxType></R:bigbox>
<R:author/> <R:author><R:Name>Hadrian</R:Name></R:author>
<creationdate/> <D:creationdate>1997-12-01T17:42:21-08:00</D:creationdate>
<displayname/> <D:displayname>Example collection</D:displayname>
<resourcetype/> <D:resourcetype><D:collection/></D:resourcetype>
<supportedlock/> <D:supportedlock>
</prop> <D:lockentry>
<status>HTTP/1.1 200 OK</status> <D:lockscope><D:exclusive/></D:lockscope>
</propstat> <D:locktype><D:write/></D:locktype>
</response> </D:lockentry>
<response> <D:lockentry>
<href>http://www.foo.bar/container/front.html</href> <D:lockscope><D:shared/></D:lockscope>
<propstat> <D:locktype><D:write/></D:locktype>
<prop xmlns:R="http://www.foo.bar/boxschema/"> </D:lockentry>
<R:bigbox/> </D:supportedlock>
<creationdate/> </D:prop>
<displayname/> <D:status>HTTP/1.1 200 OK</D:status>
<getcontentlength/> </D:propstat>
<getcontenttype/> </D:response>
<getetag/> <D:response>
<getlastmodified/> <D:href>/container/front.html</D:href>
<resourcetype/> <D:propstat>
<supportedlock/> <D:prop xmlns:R="http://ns.example.com/boxschema/">
</prop> <R:bigbox><R:BoxType>Box type B</R:BoxType>
<status>HTTP/1.1 200 OK</status> </R:bigbox>
</propstat> <D:creationdate>1997-12-01T18:27:21-08:00</D:creationdate>
</response> <D:displayname>Example HTML resource</D:displayname>
</multistatus> <D:getcontentlength>4525</D:getcontentlength>
<D:getcontenttype>text/html</D:getcontenttype>
<D:getetag>"zzyzx"</D:getetag>
<D:getlastmodified
>Mon, 12 Jan 1998 09:25:56 GMT</D:getlastmodified>
<D:resourcetype/>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
In this example, PROPFIND is invoked on the collection resource </D:propstat>
http://www.foo.bar/container/, with a propfind XML element containing </D:response>
the propname XML element, meaning the name of all properties should </D:multistatus>
be returned. Since no Depth header is present, it assumes its
default value of "infinity", meaning the name of the properties on
the collection and all its progeny should be returned.
Consistent with the previous example, resource In this example, PROPFIND was invoked on the resource
http://www.foo.bar/container/ has six properties defined on it, http://www.example.com/container/ with a Depth header of 1, meaning
http://www.foo.bar/boxschema/bigbox, the request applies to the resource and its children, and a propfind
http://www.foo.bar/boxschema/author, DAV:creationdate, DAV: XML element containing the allprop XML element, meaning the request
should return the name and value of all the dead properties defined
on the resources, plus the name and value of all the properties
defined in this specification. This example illustrates the use of
relative references in the 'href' elements of the response.
The resource http://www.example.com/container/ has six properties
defined on it: 'bigbox' and 'author in the
"http://ns.example.com/boxschema/" namespace, DAV:creationdate, DAV:
displayname, DAV:resourcetype, and DAV:supportedlock. displayname, DAV:resourcetype, and DAV:supportedlock.
The resource http://www.foo.bar/container/index.html, a member of the The last four properties are WebDAV-specific, defined in Section 15.
"container" collection, has nine properties defined on it, Since GET is not supported on this resource, the get* properties
http://www.foo.bar/boxschema/bigbox, DAV:creationdate, DAV: (e.g., DAV:getcontentlength) are not defined on this resource. The
WebDAV-specific properties assert that "container" was created on
December 1, 1997, at 5:42:21PM, in a time zone 8 hours west of GMT
(DAV:creationdate), has a name of "Example collection" (DAV:
displayname), a collection resource type (DAV:resourcetype), and
supports exclusive write and shared write locks (DAV:supportedlock).
The resource http://www.example.com/container/front.html has nine
properties defined on it:
'bigbox' in the "http://ns.example.com/boxschema/" namespace (another
instance of the "bigbox" property type), DAV:creationdate, DAV:
displayname, DAV:getcontentlength, DAV:getcontenttype, DAV:getetag, displayname, DAV:getcontentlength, DAV:getcontenttype, DAV:getetag,
DAV:getlastmodified, DAV:resourcetype, and DAV:supportedlock. DAV:getlastmodified, DAV:resourcetype, and DAV:supportedlock.
This example also demonstrates the use of XML namespace scoping, and The DAV-specific properties assert that "front.html" was created on
the default namespace. Since the "xmlns" attribute does not contain December 1, 1997, at 6:27:21PM, in a time zone 8 hours west of GMT
an explicit "shorthand name" (prefix) letter, the namespace applies (DAV:creationdate), has a name of "Example HTML resource" (DAV:
by default to all enclosed elements. Hence, all elements which do displayname), a content length of 4525 bytes (DAV:getcontentlength),
not explicitly state the namespace to which they belong are members a MIME type of "text/html" (DAV:getcontenttype), an entity tag of
of the "DAV:" namespace schema. "zzyzx" (DAV:getetag), was last modified on Monday, January 12, 1998,
at 09:25:56 GMT (DAV:getlastmodified), has an empty resource type,
meaning that it is not a collection (DAV:resourcetype), and supports
both exclusive write and shared write locks (DAV:supportedlock).
8.2. PROPPATCH 9.1.6. Example - Using 'allprop' with 'include'
>>Request
PROPFIND /mycol/ HTTP/1.1
Host: www.example.com
Depth: 1
Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:allprop/>
<D:include>
<D:supported-live-property-set/>
<D:supported-report-set/>
</D:include>
</D:propfind>
In this example, PROPFIND is executed on the resource
http://www.example.com/mycol/ and its internal member resources. The
client requests the values of all live properties defined in this
specification, plus all dead properties, plus two more live
properties defined in [RFC3253]. The response is not shown.
9.2. PROPPATCH Method
The PROPPATCH method processes instructions specified in the request The PROPPATCH method processes instructions specified in the request
body to set and/or remove properties defined on the resource body to set and/or remove properties defined on the resource
identified by the Request-URI. identified by the Request-URI.
All DAV compliant resources MUST support the PROPPATCH method and All DAV compliant resources MUST support the PROPPATCH method and
MUST process instructions that are specified using the MUST process instructions that are specified using the
propertyupdate, set, and remove XML elements of the DAV schema. propertyupdate, set, and remove XML elements. Execution of the
Execution of the directives in this method is, of course, subject to directives in this method is, of course, subject to access control
access control constraints. DAV compliant resources SHOULD support constraints. DAV compliant resources SHOULD support the setting of
the setting of arbitrary dead properties. arbitrary dead properties.
The request message body of a PROPPATCH method MUST contain the The request message body of a PROPPATCH method MUST contain the
propertyupdate XML element. Instruction processing MUST occur in the propertyupdate XML element.
order instructions are received (i.e., from top to bottom).
Servers MUST process PROPPATCH instructions in document order (an
exception to the normal rule that ordering is irrelevant).
Instructions MUST either all be executed or none executed. Thus if Instructions MUST either all be executed or none executed. Thus if
any error occurs during processing all executed instructions MUST be any error occurs during processing all executed instructions MUST be
undone and a proper error result returned. Instruction processing undone and a proper error result returned. Instruction processing
details can be found in the definition of the set and remove details can be found in the definition of the set and remove
instructions in Section 12.13. instructions in Section 14.23 and Section 14.26.
8.2.1. Status Codes for use with 207 (Multi-Status) If a server attempts to make any of the property changes in a
PROPPATCH request (i.e. the request is not rejected for high-level
errors before processing the body), the response MUST be a Multi-
Status response as described in Section 9.2.1.
The following are examples of response codes one would expect to be This method is idempotent, but not safe (see Section 9.1 of
used in a 207 (Multi-Status) response for this method. Note, [RFC2616]). Responses to this method MUST NOT be cached.
however, that unless explicitly prohibited any 2/3/4/5xx series
response code may be used in a 207 (Multi-Status) response.
200 (OK) - The command succeeded. As there can be a mixture of sets 9.2.1. Status Codes for Use in 'propstat' Element
and removes in a body, a 201 (Created) seems inappropriate.
In PROPPATCH responses, information about individual properties is
returned inside 'propstat' elements (see Section 14.22), each
containing an individual 'status' element containing information
about the properties appearing in it. The list below summarizes the
most common status codes used inside 'propstat', however clients
should be prepared to handle other 2/3/4/5xx series status codes as
well.
200 (OK) - The property set or change succeeded. Note that if this
appears for one property, it appears for every property in the
response, due to the atomicity of PROPPATCH.
403 (Forbidden) - The client, for reasons the server chooses not to 403 (Forbidden) - The client, for reasons the server chooses not to
specify, cannot alter one of the properties. specify, cannot alter one of the properties.
403 (Forbidden): The client has attempted to set a protected
property, such as DAV:getetag. If returning this error, the server
SHOULD use the precondition code 'cannot-modify-protected-property'
inside the response body.
409 (Conflict) - The client has provided a value whose semantics are 409 (Conflict) - The client has provided a value whose semantics are
not appropriate for the property. This includes trying to set read- not appropriate for the property.
only properties.
423 (Locked) - The specified resource is locked and the client either 424 (Failed Dependency) - The property change could not be made
is not a lock owner or the lock type requires a lock token to be because of another property change that failed.
submitted and the client did not submit it.
507 (Insufficient Storage) - The server did not have sufficient space 507 (Insufficient Storage) - The server did not have sufficient space
to record the property. to record the property.
8.2.2. Example - PROPPATCH 9.2.2. Example - PROPPATCH
>>Request >>Request
PROPPATCH /bar.html HTTP/1.1 PROPPATCH /bar.html HTTP/1.1
Host: www.foo.com Host: www.example.com
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:" <D:propertyupdate xmlns:D="DAV:"
xmlns:Z="http://www.w3.com/standards/z39.50/"> xmlns:Z="http://ns.example.com/standards/z39.50/">
<D:set> <D:set>
<D:prop> <D:prop>
<Z:authors> <Z:Authors>
<Z:Author>Jim Whitehead</Z:Author> <Z:Author>Jim Whitehead</Z:Author>
<Z:Author>Roy Fielding</Z:Author> <Z:Author>Roy Fielding</Z:Author>
</Z:authors> </Z:Authors>
</D:prop> </D:prop>
</D:set> </D:set>
<D:remove> <D:remove>
<D:prop><Z:Copyright-Owner/></D:prop> <D:prop><Z:Copyright-Owner/></D:prop>
</D:remove> </D:remove>
</D:propertyupdate> </D:propertyupdate>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:" <D:multistatus xmlns:D="DAV:"
xmlns:Z="http://www.w3.com/standards/z39.50"> xmlns:Z="http://ns.example.com/standards/z39.50/">
<D:response> <D:response>
<D:href>http://www.foo.com/bar.html</D:href> <D:href>http://www.example.com/bar.html</D:href>
<D:propstat> <D:propstat>
<D:prop><Z:Authors/></D:prop> <D:prop><Z:Authors/></D:prop>
<D:status>HTTP/1.1 424 Failed Dependency</D:status> <D:status>HTTP/1.1 424 Failed Dependency</D:status>
</D:propstat> </D:propstat>
<D:propstat> <D:propstat>
<D:prop><Z:Copyright-Owner/></D:prop> <D:prop><Z:Copyright-Owner/></D:prop>
<D:status>HTTP/1.1 409 Conflict</D:status> <D:status>HTTP/1.1 409 Conflict</D:status>
</D:propstat> </D:propstat>
<D:responsedescription> Copyright Owner can not be deleted or <D:responsedescription> Copyright Owner can not be deleted or
altered.</D:responsedescription> altered.</D:responsedescription>
</D:response> </D:response>
</D:multistatus> </D:multistatus>
In this example, the client requests the server to set the value of In this example, the client requests the server to set the value of
the http://www.w3.com/standards/z39.50/Authors property, and to the "Authors" property in the
remove the property "http://ns.example.com/standards/z39.50/" namespace, and to remove
http://www.w3.com/standards/z39.50/Copyright-Owner. Since the the property "Copyright-Owner" in the same namespace. Since the
Copyright-Owner property could not be removed, no property Copyright-Owner property could not be removed, no property
modifications occur. The 424 (Failed Dependency) status code for the modifications occur. The 424 (Failed Dependency) status code for the
Authors property indicates this action would have succeeded if it Authors property indicates this action would have succeeded if it
were not for the conflict with removing the Copyright-Owner property. were not for the conflict with removing the Copyright-Owner property.
8.3. MKCOL Method 9.3. MKCOL Method
The MKCOL method is used to create a new collection. All DAV
compliant resources MUST support the MKCOL method.
8.3.1. Request
MKCOL creates a new collection resource at the location specified by MKCOL creates a new collection resource at the location specified by
the Request-URI. If the resource identified by the Request-URI is the Request-URI. If the Request-URI is already mapped to a resource
non-null then the MKCOL MUST fail. During MKCOL processing, a server then the MKCOL MUST fail. During MKCOL processing, a server MUST
MUST make the Request-URI a member of its parent collection, unless make the Request-URI an internal member of its parent collection,
the Request-URI is "/". If no such ancestor exists, the method MUST unless the Request-URI is "/". If no such ancestor exists, the
fail. When the MKCOL operation creates a new collection resource, method MUST fail. When the MKCOL operation creates a new collection
all ancestors MUST already exist, or the method MUST fail with a 409 resource, all ancestors MUST already exist, or the method MUST fail
(Conflict) status code. For example, if a request to create with a 409 (Conflict) status code. For example, if a request to
collection /a/b/c/d/ is made, and neither /a/b/ nor /a/b/c/ exists, create collection /a/b/c/d/ is made, and /a/b/c/ does not exist, the
the request must fail. request must fail.
When MKCOL is invoked without a request body, the newly created When MKCOL is invoked without a request body, the newly created
collection SHOULD have no members. collection SHOULD have no members.
A MKCOL request message may contain a message body. The behavior of A MKCOL request message may contain a message body. The precise
a MKCOL request when the body is present is limited to creating behavior of a MKCOL request when the body is present is undefined,
collections, members of a collection, bodies of members and but limited to creating collections, members of a collection, bodies
properties on the collections or members. If the server receives a of members and properties on the collections or members. If the
MKCOL request entity type it does not support or understand it MUST server receives a MKCOL request entity type it does not support or
respond with a 415 (Unsupported Media Type) status code. The exact understand it MUST respond with a 415 (Unsupported Media Type) status
behavior of MKCOL for various request media types is undefined in code. If the server decides to reject the request based on the
this document, and will be specified in separate documents. presence of an entity or the type of an entity, it should use the 415
(Unsupported Media Type) status code.
8.3.2. Status Codes This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
Responses from a MKCOL request MUST NOT be cached as MKCOL has non- 9.3.1. MKCOL Status Codes
idempotent semantics.
201 (Created) - The collection or structured resource was created in In addition to the general status codes possible, the following
its entirety. status codes have specific applicability to MKCOL:
201 (Created) - The collection was created.
403 (Forbidden) - This indicates at least one of two conditions: 1) 403 (Forbidden) - This indicates at least one of two conditions: 1)
the server does not allow the creation of collections at the given the server does not allow the creation of collections at the given
location in its namespace, or 2) the parent collection of the location in its URL namespace, or 2) the parent collection of the
Request-URI exists but cannot accept members. Request-URI exists but cannot accept members.
405 (Method Not Allowed) - MKCOL can only be executed on a deleted/ 405 (Method Not Allowed) - MKCOL can only be executed on an unmapped
non-existent resource. URL.
409 (Conflict) - A collection cannot be made at the Request-URI until 409 (Conflict) - A collection cannot be made at the Request-URI until
one or more intermediate collections have been created. one or more intermediate collections have been created. The server
MUST NOT create those intermediate collections automatically.
415 (Unsupported Media Type)- The server does not support the request 415 (Unsupported Media Type) - The server does not support the
type of the body. request body type (although bodies are legal on MKCOL requests, since
this specification doesn't define any, the server is likely not to
support any given body type).
507 (Insufficient Storage) - The resource does not have sufficient 507 (Insufficient Storage) - The resource does not have sufficient
space to record the state of the resource after the execution of this space to record the state of the resource after the execution of this
method. method.
8.3.3. Example - MKCOL 9.3.2. Example - MKCOL
This example creates a collection called /webdisc/xfiles/ on the This example creates a collection called /webdisc/xfiles/ on the
server www.server.org. server www.example.com.
>>Request >>Request
MKCOL /webdisc/xfiles/ HTTP/1.1 MKCOL /webdisc/xfiles/ HTTP/1.1
Host: www.server.org Host: www.example.com
>>Response >>Response
HTTP/1.1 201 Created HTTP/1.1 201 Created
8.4. GET, HEAD for Collections 9.4. GET, HEAD for Collections
The semantics of GET are unchanged when applied to a collection, The semantics of GET are unchanged when applied to a collection,
since GET is defined as, "retrieve whatever information (in the form since GET is defined as, "retrieve whatever information (in the form
of an entity) is identified by the Request-URI" [RFC2068]. GET when of an entity) is identified by the Request-URI" [RFC2616]. GET when
applied to a collection may return the contents of an "index.html" applied to a collection may return the contents of an "index.html"
resource, a human-readable view of the contents of the collection, or resource, a human-readable view of the contents of the collection, or
something else altogether. Hence it is possible that the result of a something else altogether. Hence it is possible that the result of a
GET on a collection will bear no correlation to the membership of the GET on a collection will bear no correlation to the membership of the
collection. collection.
Similarly, since the definition of HEAD is a GET without a response Similarly, since the definition of HEAD is a GET without a response
message body, the semantics of HEAD are unmodified when applied to message body, the semantics of HEAD are unmodified when applied to
collection resources. collection resources.
8.5. POST for Collections 9.5. POST for Collections
Since by definition the actual function performed by POST is Since by definition the actual function performed by POST is
determined by the server and often depends on the particular determined by the server and often depends on the particular
resource, the behavior of POST when applied to collections cannot be resource, the behavior of POST when applied to collections cannot be
meaningfully modified because it is largely undefined. Thus the meaningfully modified because it is largely undefined. Thus the
semantics of POST are unmodified when applied to a collection. semantics of POST are unmodified when applied to a collection.
8.6. DELETE 9.6. DELETE Requirements
8.6.1. DELETE for Non-Collection Resources DELETE is defined in [RFC2616], Section 9.7, to "delete the resource
identified by the Request-URI". However, WebDAV changes some DELETE
handling requirements.
If the DELETE method is issued to a non-collection resource whose A server processing a successful DELETE request:
URIs are an internal member of one or more collections, then during
DELETE processing a server MUST remove any URI for the resource
identified by the Request-URI from collections which contain it as a
member.
8.6.2. DELETE for Collections MUST destroy locks rooted on the deleted resource
MUST remove the mapping from the Request-URI to any resource.
Thus, after a successful DELETE operation (and in the absence of
other actions) a subsequent GET/HEAD/PROPFIND request to the target
Request-URI MUST return 404 (Not Found).
9.6.1. DELETE for Collections
The DELETE method on a collection MUST act as if a "Depth: infinity" The DELETE method on a collection MUST act as if a "Depth: infinity"
header was used on it. A client MUST NOT submit a Depth header with header was used on it. A client MUST NOT submit a Depth header with
a DELETE on a collection with any value but infinity. a DELETE on a collection with any value but infinity.
DELETE instructs that the collection specified in the Request-URI and DELETE instructs that the collection specified in the Request-URI and
all resources identified by its internal member URIs are to be all resources identified by its internal member URLs are to be
deleted. deleted.
If any resource identified by a member URI cannot be deleted then all If any resource identified by a member URL cannot be deleted then all
of the member's ancestors MUST NOT be deleted, so as to maintain of the member's ancestors MUST NOT be deleted, so as to maintain URL
namespace consistency. namespace consistency.
Any headers included with DELETE MUST be applied in processing every Any headers included with DELETE MUST be applied in processing every
resource to be deleted. resource to be deleted.
When the DELETE method has completed processing it MUST result in a When the DELETE method has completed processing it MUST result in a
consistent namespace. consistent URL namespace.
If an error occurs with a resource other than the resource identified If an error occurs deleting a member resource (a resource other than
in the Request-URI then the response MUST be a 207 (Multi-Status). the resource identified in the Request-URI) then the response can be
424 (Failed Dependency) errors SHOULD NOT be in the 207 (Multi- a 207 (Multi-Status). Multi-Status is used here to indicate which
Status). They can be safely left out because the client will know internal resources could NOT be deleted, including an error code
that the ancestors of a resource could not be deleted when the client which should help the client understand which resources caused the
receives an error for the ancestor's progeny. Additionally 204 (No failure. For example, the Multi-Status body could include a response
Content) errors SHOULD NOT be returned in the 207 (Multi-Status). with status 423 (Locked) if an internal resource was locked.
The reason for this prohibition is that 204 (No Content) is the
default success code.
8.6.2.1. Example - DELETE The server MAY return a 4xx status response, rather than a 207, if
the request failed completely.
424 (Failed Dependency) status codes SHOULD NOT be in the 207 (Multi-
Status) response for DELETE. They can be safely left out because the
client will know that the ancestors of a resource could not be
deleted when the client receives an error for the ancestor's progeny.
Additionally 204 (No Content) errors SHOULD NOT be returned in the
207 (Multi-Status). The reason for this prohibition is that 204 (No
Content) is the default success code.
9.6.2. Example - DELETE
>>Request >>Request
DELETE /container/ HTTP/1.1 DELETE /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d="DAV:"> <d:multistatus xmlns:d="DAV:">
<d:response> <d:response>
<d:href>http://www.foo.bar/container/resource3</d:href> <d:href>http://www.example.com/container/resource3</d:href>
<d:status>HTTP/1.1 423 Locked</d:status> <d:status>HTTP/1.1 423 Locked</d:status>
</d:response> <d:error><d:lock-token-submitted/></d:error>
</d:multistatus> </d:response>
</d:multistatus>
In this example the attempt to delete In this example the attempt to delete
http://www.foo.bar/container/resource3 failed because it is locked, http://www.example.com/container/resource3 failed because it is
and no lock token was submitted with the request. Consequently, the locked, and no lock token was submitted with the request.
attempt to delete http://www.foo.bar/container/ also failed. Thus Consequently, the attempt to delete http://www.example.com/container/
the client knows that the attempt to delete also failed. Thus the client knows that the attempt to delete
http://www.foo.bar/container/ must have also failed since the parent http://www.example.com/container/ must have also failed since the
can not be deleted unless its child has also been deleted. Even parent can not be deleted unless its child has also been deleted.
though a Depth header has not been included, a depth of infinity is Even though a Depth header has not been included, a depth of infinity
assumed because the method is on a collection. is assumed because the method is on a collection.
8.7. PUT 9.7. PUT Requirements
8.7.1. PUT for Non-Collection Resources 9.7.1. PUT for Non-Collection Resources
A PUT performed on an existing resource replaces the GET response A PUT performed on an existing resource replaces the GET response
entity of the resource. Properties defined on the resource may be entity of the resource. Properties defined on the resource may be
recomputed during PUT processing but are not otherwise affected. For recomputed during PUT processing but are not otherwise affected. For
example, if a server recognizes the content type of the request body, example, if a server recognizes the content type of the request body,
it may be able to automatically extract information that could be it may be able to automatically extract information that could be
profitably exposed as properties. profitably exposed as properties.
A PUT that would result in the creation of a resource without an A PUT that would result in the creation of a resource without an
appropriately scoped parent collection MUST fail with a 409 appropriately scoped parent collection MUST fail with a 409
(Conflict). (Conflict).
8.7.2. PUT for Collections A PUT request allows a client to indicate what media type an entity
body has, and whether it should change if overwritten. Thus, a
client SHOULD provide a Content-Type for a new resource if any is
known. If the client does not provide a Content-Type for a new
resource, the server MAY create a resource with no Content-Type
assigned, or it MAY attempt to assign a Content-Type.
As defined in the HTTP/1.1 specification [RFC2068], the "PUT method Note that although a recipient ought generally to treat metadata
requests that the enclosed entity be stored under the supplied supplied with an HTTP request as authoritative, in practice there's
Request-URI." Since submission of an entity representing a no guarantee that a server will accept client-supplied metadata (e.g.
collection would implicitly encode creation and deletion of any request header beginning with "Content-"). Many servers do not
resources, this specification intentionally does not define a allow configuring the Content-Type on a per-resource basis in the
transmission format for creating a collection using PUT. Instead, first place. Thus, clients can't always rely on the ability to
the MKCOL method is defined to create collections. directly influence the content type by including a Content-Type
request header.
When the PUT operation creates a new non-collection resource all 9.7.2. PUT for Collections
ancestors MUST already exist. If all ancestors do not exist, the
method MUST fail with a 409 (Conflict) status code. For example, if
resource /a/b/c/d.html is to be created and /a/b/c/ does not exist,
then the request must fail.
8.8. COPY Method This specification does not define the behavior of the PUT method for
existing collections. A PUT request to an existing collection MAY be
treated as an error (405 Method Not Allowed).
The COPY method creates a duplicate of the source resource, The MKCOL method is defined to create collections.
identified by the Request-URI, in the destination resource,
identified by the URI in the Destination header. The Destination 9.8. COPY Method
header MUST be present. The exact behavior of the COPY method
depends on the type of the source resource. The COPY method creates a duplicate of the source resource identified
by the Request-URI, in the destination resource identified by the URI
in the Destination header. The Destination header MUST be present.
The exact behavior of the COPY method depends on the type of the
source resource.
All WebDAV compliant resources MUST support the COPY method. All WebDAV compliant resources MUST support the COPY method.
However, support for the COPY method does not guarantee the ability However, support for the COPY method does not guarantee the ability
to copy a resource. For example, separate programs may control to copy a resource. For example, separate programs may control
resources on the same server. As a result, it may not be possible to resources on the same server. As a result, it may not be possible to
copy a resource to a location that appears to be on the same server. copy a resource to a location that appears to be on the same server.
8.8.1. COPY for HTTP/1.1 resources This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
9.8.1. COPY for Non-collection Resources
When the source resource is not a collection the result of the COPY When the source resource is not a collection the result of the COPY
method is the creation of a new resource at the destination whose method is the creation of a new resource at the destination whose
state and behavior match that of the source resource as closely as state and behavior match that of the source resource as closely as
possible. After a successful COPY invocation, all properties on the possible. Since the environment at the destination may be different
source resource MUST be duplicated on the destination resource, than at the source due to factors outside the scope of control of the
subject to modifying headers and XML elements, following the server, such as the absence of resources required for correct
definition for copying properties. Since the environment at the operation, it may not be possible to completely duplicate the
destination may be different than at the source due to factors behavior of the resource at the destination. Subsequent alterations
outside the scope of control of the server, such as the absence of to the destination resource will not modify the source resource.
resources required for correct operation, it may not be possible to Subsequent alterations to the source resource will not modify the
completely duplicate the behavior of the resource at the destination. destination resource.
Subsequent alterations to the destination resource will not modify
the source resource. Subsequent alterations to the source resource
will not modify the destination resource.
8.8.2. COPY for Properties
The following section defines how properties on a resource are 9.8.2. COPY for Properties
handled during a COPY operation.
Live properties SHOULD be duplicated as identically behaving live After a successful COPY invocation, all dead properties on the source
properties at the destination resource. If a property cannot be resource SHOULD be duplicated on the destination resource. Live
copied live, then its value MUST be duplicated, octet-for-octet, in properties described in this document SHOULD be duplicated as
an identically named, dead property on the destination resource identically behaving live properties at the destination resource, but
subject to the effects of the propertybehavior XML element. not necessarily with the same values. Servers SHOULD NOT convert
live properties into dead properties on the destination resource,
because clients may then draw incorrect conclusions about the state
or functionality of a resource. Note that some live properties are
defined such that the absence of the property has a specific meaning
(e.g. a flag with one meaning if present and the opposite if absent),
and in these cases, a successful COPY might result in the property
being reported as "Not Found" in subsequent requests.
The propertybehavior XML element can specify that properties are When the destination is an unmapped URL, a COPY operation creates a
copied on best effort, that all live properties must be successfully new resource much like a PUT operation does. Live properties which
copied or the method must fail, or that a specified list of live are related to resource creation (such as DAV:creationdate) should
properties must be successfully copied or the method must fail. The have their values set accordingly.
propertybehavior XML element is defined in Section 12.12.
8.8.3. COPY for Collections 9.8.3. COPY for Collections
The COPY method on a collection without a Depth header MUST act as if The COPY method on a collection without a Depth header MUST act as if
a Depth header with value "infinity" was included. A client may a Depth header with value "infinity" was included. A client may
submit a Depth header on a COPY on a collection with a value of "0" submit a Depth header on a COPY on a collection with a value of "0"
or "infinity". DAV compliant servers MUST support the "0" and or "infinity". Servers MUST support the "0" and "infinity" Depth
"infinity" Depth header behaviors. header behaviors on WebDAV-compliant resources.
A COPY of depth infinity instructs that the collection resource An infinite depth COPY instructs that the collection resource
identified by the Request-URI is to be copied to the location identified by the Request-URI is to be copied to the location
identified by the URI in the Destination header, and all its internal identified by the URI in the Destination header, and all its internal
member resources are to be copied to a location relative to it, member resources are to be copied to a location relative to it,
recursively through all levels of the collection hierarchy. recursively through all levels of the collection hierarchy. Note
that an infinite depth COPY of /A/ into /A/B/ could lead to infinite
recursion if not handled correctly.
A COPY of "Depth: 0" only instructs that the collection and its A COPY of "Depth: 0" only instructs that the collection and its
properties but not resources identified by its internal member URIs, properties but not resources identified by its internal member URLs,
are to be copied. are to be copied.
Any headers included with a COPY MUST be applied in processing every Any headers included with a COPY MUST be applied in processing every
resource to be copied with the exception of the Destination header. resource to be copied with the exception of the Destination header.
The Destination header only specifies the destination URI for the The Destination header only specifies the destination URI for the
Request-URI. When applied to members of the collection identified by Request-URI. When applied to members of the collection identified by
the Request-URI the value of Destination is to be modified to reflect the Request-URI the value of Destination is to be modified to reflect
the current location in the hierarchy. So, if the Request- URI is the current location in the hierarchy. So, if the Request-URI is /a/
/a/ with Host header value http://fun.com/ and the Destination is with Host header value http://example.com/ and the Destination is
http://fun.com/b/ then when http://fun.com/a/c/d is processed it must http://example.com/b/ then when http://example.com/a/c/d is processed
use a Destination of http://fun.com/b/c/d. it must use a Destination of http://example.com/b/c/d.
When the COPY method has completed processing it MUST have created a When the COPY method has completed processing it MUST have created a
consistent namespace at the destination (see Section 5.1 for the consistent URL namespace at the destination (see Section 5.1 for the
definition of namespace consistency). However, if an error occurs definition of namespace consistency). However, if an error occurs
while copying an internal collection, the server MUST NOT copy any while copying an internal collection, the server MUST NOT copy any
resources identified by members of this collection (i.e., the server resources identified by members of this collection (i.e., the server
must skip this subtree), as this would create an inconsistent must skip this subtree), as this would create an inconsistent
namespace. After detecting an error, the COPY operation SHOULD try namespace. After detecting an error, the COPY operation SHOULD try
to finish as much of the original copy operation as possible (i.e., to finish as much of the original copy operation as possible (i.e.,
the server should still attempt to copy other subtrees and their the server should still attempt to copy other subtrees and their
members, that are not descendents of an error-causing collection). members, that are not descendents of an error-causing collection).
So, for example, if an infinite depth copy operation is performed on So, for example, if an infinite depth copy operation is performed on
collection /a/, which contains collections /a/b/ and /a/c/, and an collection /a/, which contains collections /a/b/ and /a/c/, and an
error occurs copying /a/b/, an attempt should still be made to copy error occurs copying /a/b/, an attempt should still be made to copy
/a/c/. Similarly, after encountering an error copying a non- /a/c/. Similarly, after encountering an error copying a non-
collection resource as part of an infinite depth copy, the server collection resource as part of an infinite depth copy, the server
SHOULD try to finish as much of the original copy operation as SHOULD try to finish as much of the original copy operation as
possible. possible.
If an error in executing the COPY method occurs with a resource other If an error in executing the COPY method occurs with a resource other
than the resource identified in the Request-URI then the response than the resource identified in the Request-URI then the response
MUST be a 207 (Multi-Status). MUST be a 207 (Multi-Status), and the URL of the resource causing the
failure MUST appear with the specific error.
The 424 (Failed Dependency) status code SHOULD NOT be returned in the The 424 (Failed Dependency) status code SHOULD NOT be returned in the
207 (Multi-Status) response from a COPY method. These responses can 207 (Multi-Status) response from a COPY method. These responses can
be safely omitted because the client will know that the progeny of a be safely omitted because the client will know that the progeny of a
resource could not be copied when the client receives an error for resource could not be copied when the client receives an error for
the parent. Additionally 201 (Created)/204 (No Content) status codes the parent. Additionally 201 (Created)/204 (No Content) status codes
SHOULD NOT be returned as values in 207 (Multi-Status) responses from SHOULD NOT be returned as values in 207 (Multi-Status) responses from
COPY methods. They, too, can be safely omitted because they are the COPY methods. They, too, can be safely omitted because they are the
default success codes. default success codes.
8.8.4. COPY and the Overwrite Header 9.8.4. COPY and Overwriting Destination Resources
If a resource exists at the destination and the Overwrite header is If a COPY request has an Overwrite header with a value of "F", and a
"T" then prior to performing the copy the server MUST perform a resource exists at the Destination URL, the server MUST fail the
DELETE with "Depth: infinity" on the destination resource. If the request.
Overwrite header is set to "F" then the operation will fail.
8.8.5. Status Codes When a server executes a COPY request and overwrites a destination
resource, the exact behavior MAY depend on many factors, including
WebDAV extension capabilities (see particularly [RFC3253]). For
example, when an ordinary resource is overwritten, the server could
delete the target resource before doing the copy, or could do an in-
place overwrite to preserve live properties.
When a collection is overwritten, the membership of the destination
collection after the successful COPY request MUST be the same
membership as the source collection immediately before the COPY.
Thus, merging the membership of the source and destination
collections together in the destination is not a compliant behavior.
In general, if clients require the state of the destination URL to be
wiped out prior to a COPY (e.g. to force live properties to be
reset), then the client could send a DELETE to the destination before
the COPY request to ensure this reset.
9.8.5. Status Codes
In addition to the general status codes possible, the following
status codes have specific applicability to COPY:
201 (Created) - The source resource was successfully copied. The 201 (Created) - The source resource was successfully copied. The
copy operation resulted in the creation of a new resource. COPY operation resulted in the creation of a new resource.
204 (No Content) - The source resource was successfully copied to a 204 (No Content) - The source resource was successfully copied to a
pre-existing destination resource. pre-existing destination resource.
403 (Forbidden) - The source and destination URIs are the same. 207 (Multi-Status) - Multiple resources were to be affected by the
COPY, but errors on some of them prevented the operation from taking
place. Specific error messages, together with the most appropriate
of the source and destination URLs, appear in the body of the multi-
status response. E.g. if a destination resource was locked and could
not be overwritten, then the destination resource URL appears with
the 423 (Locked) status.
403 (Forbidden) - The operation is forbidden. A special case for
COPY could be that the source and destination resources are the same
resource.
409 (Conflict) - A resource cannot be created at the destination 409 (Conflict) - A resource cannot be created at the destination
until one or more intermediate collections have been created. until one or more intermediate collections have been created. The
server MUST NOT create those intermediate collections automatically.
412 (Precondition Failed) - The server was unable to maintain the 412 (Precondition Failed) - A precondition header check failed, e.g.
liveness of the properties listed in the propertybehavior XML element the Overwrite header is "F" and the destination URL is already mapped
or the Overwrite header is "F" and the state of the destination to a resource.
resource is non-null.
423 (Locked) - The destination resource was locked. 423 (Locked) - The destination resource, or resource within the
destination collection, was locked. This response SHOULD contain the
'lock-token-submitted' precondition element.
502 (Bad Gateway) - This may occur when the destination is on another 502 (Bad Gateway) - This may occur when the destination is on another
server and the destination server refuses to accept the resource. server, repository or URL namespace. Either the source namespace
does not support copying to the destination namespace, or the
destination namespace refuses to accept the resource. The client may
wish to try GET/PUT and PROPFIND/PROPPATCH instead.
507 (Insufficient Storage) - The destination resource does not have 507 (Insufficient Storage) - The destination resource does not have
sufficient space to record the state of the resource after the sufficient space to record the state of the resource after the
execution of this method. execution of this method.
8.8.6. Example - COPY with Overwrite 9.8.6. Example - COPY with Overwrite
This example shows resource This example shows resource
http://www.ics.uci.edu/~fielding/index.html being copied to the http://www.example.com/~fielding/index.html being copied to the
location http://www.ics.uci.edu/users/f/fielding/index.html. The 204 location http://www.example.com/users/f/fielding/index.html. The 204
(No Content) status code indicates the existing resource at the (No Content) status code indicates the existing resource at the
destination was overwritten. destination was overwritten.
>>Request >>Request
COPY /~fielding/index.html HTTP/1.1 COPY /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example.com/users/f/fielding/index.html
>>Response >>Response
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
8.8.7. Example - COPY with No Overwrite 9.8.7. Example - COPY with No Overwrite
The following example shows the same copy operation being performed, The following example shows the same copy operation being performed,
but with the Overwrite header set to "F." A response of 412 but with the Overwrite header set to "F." A response of 412
(Precondition Failed) is returned because the destination resource (Precondition Failed) is returned because the destination URL is
has a non-null state. already mapped to a resource.
>>Request >>Request
COPY /~fielding/index.html HTTP/1.1 COPY /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example.com/users/f/fielding/index.html
Overwrite: F Overwrite: F
>>Response >>Response
HTTP/1.1 412 Precondition Failed HTTP/1.1 412 Precondition Failed
8.8.8. Example - COPY of a Collection 9.8.8. Example - COPY of a Collection
>>Request >>Request
COPY /container/ HTTP/1.1 COPY /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Destination: http://www.foo.bar/othercontainer/ Destination: http://www.example.com/othercontainer/
Depth: infinity Depth: infinity
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<d:propertybehavior xmlns:d="DAV:">
<d:keepalive>*</d:keepalive>
</d:propertybehavior>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d="DAV:">
<d:response> <d:multistatus xmlns:d="DAV:">
<d:href>http://www.foo.bar/othercontainer/R2/</d:href> <d:response>
<d:status>HTTP/1.1 412 Precondition Failed</d:status> <d:href>http://www.example.com/othercontainer/R2/</d:href>
</d:response> <d:status>HTTP/1.1 423 Locked</d:status>
</d:multistatus> <d:error><d:lock-token-submitted/></d:error>
</d:response>
</d:multistatus>
The Depth header is unnecessary as the default behavior of COPY on a The Depth header is unnecessary as the default behavior of COPY on a
collection is to act as if a "Depth: infinity" header had been collection is to act as if a "Depth: infinity" header had been
submitted. In this example most of the resources, along with the submitted. In this example most of the resources, along with the
collection, were copied successfully. However the collection R2 collection, were copied successfully. However the collection R2
failed, most likely due to a problem with maintaining the liveness of failed because the destination R2 is locked. Because there was an
properties (this is specified by the propertybehavior XML element). error copying R2, none of R2's members were copied. However no
Because there was an error copying R2, none of R2's members were errors were listed for those members due to the error minimization
copied. However no errors were listed for those members due to the rules.
error minimization rules given in Section 8.8.3.
8.9. MOVE Method 9.9. MOVE Method
The MOVE operation on a non-collection resource is the logical The MOVE operation on a non-collection resource is the logical
equivalent of a copy (COPY), followed by consistency maintenance equivalent of a copy (COPY), followed by consistency maintenance
processing, followed by a delete of the source, where all three processing, followed by a delete of the source, where all three
actions are performed atomically. The consistency maintenance step actions are performed in a single operation. The consistency
allows the server to perform updates caused by the move, such as maintenance step allows the server to perform updates caused by the
updating all URIs other than the Request-URI which identify the move, such as updating all URLs other than the Request-URI which
source resource, to point to the new destination resource. identify the source resource, to point to the new destination
Consequently, the Destination header MUST be present on all MOVE resource.
methods and MUST follow all COPY requirements for the COPY part of
the MOVE method. All DAV compliant resources MUST support the MOVE
method. However, support for the MOVE method does not guarantee the
ability to move a resource to a particular destination.
For example, separate programs may actually control different sets of The Destination header MUST be present on all MOVE methods and MUST
resources on the same server. Therefore, it may not be possible to follow all COPY requirements for the COPY part of the MOVE method.
move a resource within a namespace that appears to belong to the same All WebDAV compliant resources MUST support the MOVE method.
server.
Support for the MOVE method does not guarantee the ability to move a
resource to a particular destination. For example, separate programs
may actually control different sets of resources on the same server.
Therefore, it may not be possible to move a resource within a
namespace that appears to belong to the same server.
If a resource exists at the destination, the destination resource If a resource exists at the destination, the destination resource
will be DELETEd as a side-effect of the MOVE operation, subject to will be deleted as a side-effect of the MOVE operation, subject to
the restrictions of the Overwrite header. the restrictions of the Overwrite header.
8.9.1. MOVE for Properties This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
The behavior of properties on a MOVE, including the effects of the 9.9.1. MOVE for Properties
propertybehavior XML element, MUST be the same as specified in
Section 8.8.2.
8.9.2. MOVE for Collections Live properties described in this document SHOULD be moved along with
the resource, such that the resource has identically behaving live
properties at the destination resource, but not necessarily with the
same values. Note that some live properties are defined such that
the absence of the property has a specific meaning (e.g. a flag with
one meaning if present and the opposite if absent), and in these
cases, a successful MOVE might result in the property being reported
as "Not Found" in subsequent requests. If the live properties will
not work the same way at the destination, the server MAY fail the
request.
MOVE is frequently used by clients to rename a file without changing
its parent collection, so it's not appropriate to reset all live
properties which are set at resource creation. For example, the DAV:
creationdate property value SHOULD remain the same after a MOVE.
Dead properties MUST be moved along with the resource.
9.9.2. MOVE for Collections
A MOVE with "Depth: infinity" instructs that the collection A MOVE with "Depth: infinity" instructs that the collection
identified by the Request-URI be moved to the URI specified in the identified by the Request-URI be moved to the address specified in
Destination header, and all resources identified by its internal the Destination header, and all resources identified by its internal
member URIs are to be moved to locations relative to it, recursively member URLs are to be moved to locations relative to it, recursively
through all levels of the collection hierarchy. through all levels of the collection hierarchy.
The MOVE method on a collection MUST act as if a "Depth: infinity" The MOVE method on a collection MUST act as if a "Depth: infinity"
header was used on it. A client MUST NOT submit a Depth header on a header was used on it. A client MUST NOT submit a Depth header on a
MOVE on a collection with any value but "infinity". MOVE on a collection with any value but "infinity".
Any headers included with MOVE MUST be applied in processing every Any headers included with MOVE MUST be applied in processing every
resource to be moved with the exception of the Destination header. resource to be moved with the exception of the Destination header.
The behavior of the Destination header is the same as given for COPY The behavior of the Destination header is the same as given for COPY
on collections. on collections.
When the MOVE method has completed processing it MUST have created a When the MOVE method has completed processing it MUST have created a
consistent namespace at both the source and destination (see section consistent URL namespace at both the source and destination (see
5.1 for the definition of namespace consistency). However, if an section 5.1 for the definition of namespace consistency). However,
error occurs while moving an internal collection, the server MUST NOT if an error occurs while moving an internal collection, the server
move any resources identified by members of the failed collection MUST NOT move any resources identified by members of the failed
(i.e., the server must skip the error-causing subtree), as this would collection (i.e., the server must skip the error-causing subtree), as
create an inconsistent namespace. In this case, after detecting the this would create an inconsistent namespace. In this case, after
error, the move operation SHOULD try to finish as much of the detecting the error, the move operation SHOULD try to finish as much
original move as possible (i.e., the server should still attempt to of the original move as possible (i.e., the server should still
move other subtrees and the resources identified by their members, attempt to move other subtrees and the resources identified by their
that are not descendents of an error-causing collection). So, for members, that are not descendents of an error-causing collection).
example, if an infinite depth move is performed on collection /a/, So, for example, if an infinite depth move is performed on collection
which contains collections /a/b/ and /a/c/, and an error occurs /a/, which contains collections /a/b/ and /a/c/, and an error occurs
moving /a/b/, an attempt should still be made to try moving /a/c/. moving /a/b/, an attempt should still be made to try moving /a/c/.
Similarly, after encountering an error moving a non-collection Similarly, after encountering an error moving a non-collection
resource as part of an infinite depth move, the server SHOULD try to resource as part of an infinite depth move, the server SHOULD try to
finish as much of the original move operation as possible. finish as much of the original move operation as possible.
If an error occurs with a resource other than the resource identified If an error occurs with a resource other than the resource identified
in the Request-URI then the response MUST be a 207 (Multi-Status). in the Request-URI then the response MUST be a 207 (Multi-Status),
and the errored resource's URL MUST appear with the specific error.
The 424 (Failed Dependency) status code SHOULD NOT be returned in the The 424 (Failed Dependency) status code SHOULD NOT be returned in the
207 (Multi-Status) response from a MOVE method. These errors can be 207 (Multi-Status) response from a MOVE method. These errors can be
safely omitted because the client will know that the progeny of a safely omitted because the client will know that the progeny of a
resource could not be moved when the client receives an error for the resource could not be moved when the client receives an error for the
parent. Additionally 201 (Created)/204 (No Content) responses SHOULD parent. Additionally 201 (Created)/204 (No Content) responses SHOULD
NOT be returned as values in 207 (Multi-Status) responses from a NOT be returned as values in 207 (Multi-Status) responses from a
MOVE. These responses can be safely omitted because they are the MOVE. These responses can be safely omitted because they are the
default success codes. default success codes.
8.9.3. MOVE and the Overwrite Header 9.9.3. MOVE and the Overwrite Header
If a resource exists at the destination and the Overwrite header is If a resource exists at the destination and the Overwrite header is
"T" then prior to performing the move the server MUST perform a "T" then prior to performing the move the server MUST perform a
DELETE with "Depth: infinity" on the destination resource. If the DELETE with "Depth: infinity" on the destination resource. If the
Overwrite header is set to "F" then the operation will fail. Overwrite header is set to "F" then the operation will fail.
8.9.4. Status Codes 9.9.4. Status Codes
In addition to the general status codes possible, the following
status codes have specific applicability to MOVE:
201 (Created) - The source resource was successfully moved, and a new 201 (Created) - The source resource was successfully moved, and a new
resource was created at the destination. URL mapping was created at the destination.
204 (No Content) - The source resource was successfully moved to a 204 (No Content) - The source resource was successfully moved to a
pre-existing destination resource. URL that was already mapped.
403 (Forbidden) - The source and destination URIs are the same. 207 (Multi-Status) - Multiple resources were to be affected by the
MOVE, but errors on some of them prevented the operation from taking
place. Specific error messages, together with the most appropriate
of the source and destination URLs, appear in the body of the multi-
status response. E.g. if a source resource was locked and could not
be moved, then the source resource URL appears with the 423 (Locked)
status.
403 (Forbidden) - Among many possible reasons for forbidding a MOVE
operation, this status code is recommended for use when the source
and destination resources are the same.
409 (Conflict) - A resource cannot be created at the destination 409 (Conflict) - A resource cannot be created at the destination
until one or more intermediate collections have been created. until one or more intermediate collections have been created. The
server MUST NOT create those intermediate collections automatically.
Or, the server was unable to preserve the behavior of the live
properties and still move the resource to the destination (see
'preserved-live-properties' postcondition).
412 (Precondition Failed) - The server was unable to maintain the 412 (Precondition Failed) - A condition header failed. Specific to
liveness of the properties listed in the propertybehavior XML element MOVE, this could mean that the Overwrite header is "F" and the
or the Overwrite header is "F" and the state of the destination destination URL is already mapped to a resource.
resource is non-null.
423 (Locked) - The source or the destination resource was locked. 423 (Locked) - The source or the destination resource, the source or
destination resource parent, or some resource within the source or
destination collection, was locked. This response SHOULD contain the
'lock-token-submitted' precondition element.
502 (Bad Gateway) - This may occur when the destination is on another 502 (Bad Gateway) - This may occur when the destination is on another
server and the destination server refuses to accept the resource. server and the destination server refuses to accept the resource.
This could also occur when the destination is on another sub-section
of the same server namespace.
8.9.5. Example - MOVE of a Non-Collection 9.9.5. Example - MOVE of a Non-Collection
This example shows resource This example shows resource
http://www.ics.uci.edu/~fielding/index.html being moved to the http://www.example.com/~fielding/index.html being moved to the
location http://www.ics.uci.edu/users/f/fielding/index.html. The location http://www.example.com/users/f/fielding/index.html. The
contents of the destination resource would have been overwritten if contents of the destination resource would have been overwritten if
the destination resource had been non-null. In this case, since the destination URL was already mapped to a resource. In this case,
there was nothing at the destination resource, the response code is since there was nothing at the destination resource, the response
201 (Created). code is 201 (Created).
>>Request >>Request
MOVE /~fielding/index.html HTTP/1.1 MOVE /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example/users/f/fielding/index.html
>>Response >>Response
HTTP/1.1 201 Created HTTP/1.1 201 Created
Location: http://www.ics.uci.edu/users/f/fielding/index.html Location: http://www.example.com/users/f/fielding/index.html
8.9.6. Example - MOVE of a Collection 9.9.6. Example - MOVE of a Collection
>>Request >>Request
MOVE /container/ HTTP/1.1 MOVE /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Destination: http://www.foo.bar/othercontainer/ Destination: http://www.example.com/othercontainer/
Overwrite: F Overwrite: F
If: (<opaquelocktoken:fe184f2e-6eec-41d0-c765-01adc56e6bb4>) If: (<urn:uuid:fe184f2e-6eec-41d0-c765-01adc56e6bb4>)
(<opaquelocktoken:e454f3f3-acdc-452a-56c7-00a5c91e4b77>) (<urn:uuid:e454f3f3-acdc-452a-56c7-00a5c91e4b77>)
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<d:propertybehavior xmlns:d='DAV:'>
<d:keepalive>*</d:keepalive>
</d:propertybehavior>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d='DAV:'> <d:multistatus xmlns:d='DAV:'>
<d:response> <d:response>
<d:href>http://www.foo.bar/othercontainer/C2/</d:href> <d:href>http://www.example.com/othercontainer/C2/</d:href>
<d:status>HTTP/1.1 423 Locked</d:status> <d:status>HTTP/1.1 423 Locked</d:status>
</d:response> <d:error><d:lock-token-submitted/></d:error>
</d:multistatus> </d:response>
</d:multistatus>
In this example the client has submitted a number of lock tokens with In this example the client has submitted a number of lock tokens with
the request. A lock token will need to be submitted for every the request. A lock token will need to be submitted for every
resource, both source and destination, anywhere in the scope of the resource, both source and destination, anywhere in the scope of the
method, that is locked. In this case the proper lock token was not method, that is locked. In this case the proper lock token was not
submitted for the destination http://www.foo.bar/othercontainer/C2/. submitted for the destination
http://www.example.com/othercontainer/C2/. This means that the
This means that the resource /container/C2/ could not be moved. resource /container/C2/ could not be moved. Because there was an
Because there was an error copying /container/C2/, none of error moving /container/C2/, none of /container/C2's members were
/container/C2's members were copied. However no errors were listed moved. However no errors were listed for those members due to the
for those members due to the error minimization rules given in error minimization rules. User agent authentication has previously
Section 8.8.3. User agent authentication has previously occurred via occurred via a mechanism outside the scope of the HTTP protocol, in
a mechanism outside the scope of the HTTP protocol, in an underlying an underlying transport layer.
transport layer.
8.10. LOCK Method 9.10. LOCK Method
The following sections describe the LOCK method, which is used to The following sections describe the LOCK method, which is used to
take out a lock of any access type. These sections on the LOCK take out a lock of any access type and to refresh an existing lock.
method describe only those semantics that are specific to the LOCK These sections on the LOCK method describe only those semantics that
method and are independent of the access type of the lock being are specific to the LOCK method and are independent of the access
requested. type of the lock being requested.
Any resource which supports the LOCK method MUST, at minimum, support Any resource which supports the LOCK method MUST, at minimum, support
the XML request and response formats defined herein. the XML request and response formats defined herein.
8.10.1. Operation This method is neither idempotent nor safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
A LOCK method invocation creates the lock specified by the lockinfo 9.10.1. Creating a Lock on an Existing Resource
XML element on the Request-URI. Lock method requests SHOULD have a
XML request body which contains an owner XML element for this lock
request, unless this is a refresh request. The LOCK request may have
a Timeout header.
Clients MUST assume that locks may arbitrarily disappear at any time, A LOCK request to an existing resource will create a lock on the
regardless of the value given in the Timeout header. The Timeout resource identified by the Request-URI, provided the resource is not
header only indicates the behavior of the server if "extraordinary" already locked with a conflicting lock. The resource identified in
circumstances do not occur. For example, an administrator may remove the Request-URI becomes the root of the lock. Lock method requests
a lock at any time or the system may crash in such a way that it to create a new lock MUST have an XML request body. The server MUST
loses the record of the lock's existence. The response MUST contain preserve the information provided by the client in the 'owner' field
the value of the lockdiscovery property in a prop XML element. in the request body when the lock information is requested. The LOCK
request MAY have a Timeout header.
In order to indicate the lock token associated with a newly created When a new lock is created, the LOCK response:
lock, a Lock-Token response header MUST be included in the response
for every successful LOCK request for a new lock. Note that the
Lock-Token header would not be returned in the response for a
successful refresh LOCK request because a new lock was not created.
8.10.2. The Effect of Locks on Properties and Collections o MUST contain a body with the value of the DAV:lockdiscovery
property in a prop XML element. This MUST contain the full
information about the lock just granted, while information about
other (shared) locks is OPTIONAL.
The scope of a lock is the entire state of the resource, including o MUST include the Lock-Token response header with the token
its body and associated properties. As a result, a lock on a associated with the new lock.
resource MUST also lock the resource's properties.
For collections, a lock also affects the ability to add or remove 9.10.2. Refreshing Locks
members. The nature of the effect depends upon the type of access
control involved.
8.10.3. Locking Replicated Resources A lock is refreshed by sending a LOCK request to the URL of a
resource within the scope of the lock. This request MUST NOT have a
body and it MUST specify which lock to refresh by using the 'If'
header with a single lock token (only one lock may be refreshed at a
time). The request MAY contain a Timeout header, which a server MAY
accept to change the duration remaining on the lock to the new value.
A server MUST ignore the Depth header on a LOCK refresh.
A resource may be made available through more than one URI. However If the resource has other (shared) locks, those locks are unaffected
locks apply to resources, not URIs. Therefore a LOCK request on a by a lock refresh. Additionally, those locks do not prevent the
resource MUST NOT succeed if can not be honored by all the URIs named lock from being refreshed.
through which the resource is addressable.
8.10.4. Depth and Locking The Lock-Token header is not returned in the response for a
successful refresh LOCK request, but the LOCK response body MUST
contain the new value for the DAV:lockdiscovery property.
9.10.3. Depth and Locking
The Depth header may be used with the LOCK method. Values other than The Depth header may be used with the LOCK method. Values other than
0 or infinity MUST NOT be used with the Depth header on a LOCK 0 or infinity MUST NOT be used with the Depth header on a LOCK
method. All resources that support the LOCK method MUST support the method. All resources that support the LOCK method MUST support the
Depth header. Depth header.
A Depth header of value 0 means to just lock the resource specified A Depth header of value 0 means to just lock the resource specified
by the Request-URI. by the Request-URI.
If the Depth header is set to infinity then the resource specified in If the Depth header is set to infinity then the resource specified in
the Request-URI along with all its internal members, all the way down the Request-URI along with all its members, all the way down the
the hierarchy, are to be locked. A successful result MUST return a hierarchy, are to be locked. A successful result MUST return a
single lock token which represents all the resources that have been single lock token. Similarly, if an UNLOCK is successfully executed
locked. If an UNLOCK is successfully executed on this token, all on this token, all associated resources are unlocked. Hence, partial
associated resources are unlocked. If the lock cannot be granted to success is not an option for LOCK or UNLOCK. Either the entire
all resources, a 409 (Conflict) status code MUST be returned with a hierarchy is locked or no resources are locked.
response entity body containing a multistatus XML element describing
which resource(s) prevented the lock from being granted. Hence, If the lock cannot be granted to all resources, the server MUST
partial success is not an option. Either the entire hierarchy is return a Multi-Status response with a 'response' element for at least
locked or no resources are locked. one resource which prevented the lock from being granted, along with
a suitable status code for that failure (e.g. 403 (Forbidden) or 423
(Locked)). Additionally, if the resource causing the failure was not
the resource requested, then the server SHOULD include a 'response'
element for the Request-URI as well, with a 'status' element
containing 424 Failed Dependency.
If no Depth header is submitted on a LOCK request then the request If no Depth header is submitted on a LOCK request then the request
MUST act as if a "Depth:infinity" had been submitted. MUST act as if a "Depth:infinity" had been submitted.
8.10.5. Interaction with other Methods 9.10.4. Locking Unmapped URLs
The interaction of a LOCK with various methods is dependent upon the A successful LOCK method MUST result in the creation of an empty
lock type. However, independent of lock type, a successful DELETE of resource which is locked (and which is not a collection), when a
a resource MUST cause all of its locks to be removed. resource did not previously exist at that URL. Later on, the lock
may go away but the empty resource remains. Empty resources MUST
then appear in PROPFIND responses including that URL in the response
scope. A server MUST respond successfully to a GET request to an
empty resource, either by using a 204 No Content response, or by
using 200 OK with a Content-Length header indicating zero length
8.10.6. Lock Compatibility Table 9.10.5. Lock Compatibility Table
The table below describes the behavior that occurs when a lock The table below describes the behavior that occurs when a lock
request is made on a resource. request is made on a resource.
+-----------------------------------+-------------+----------------+ +--------------------------+----------------+-------------------+
| Current lock state / Lock request | Shared Lock | Exclusive Lock | | Current State | Shared Lock OK | Exclusive Lock OK |
+-----------------------------------+-------------+----------------+ +--------------------------+----------------+-------------------+
| None | True | True | | None | True | True |
| Shared Lock | True | False | | | | |
| Exclusive Lock | False | False* | | Shared Lock | True | False |
+-----------------------------------+-------------+----------------+ | | | |
| Exclusive Lock | False | False* |
+--------------------------+----------------+-------------------+
Legend: True = lock may be granted. False = lock MUST NOT be Legend: True = lock may be granted. False = lock MUST NOT be
granted. *=It is illegal for a principal to request the same lock granted. *=It is illegal for a principal to request the same lock
twice. twice.
The current lock state of a resource is given in the leftmost column, The current lock state of a resource is given in the leftmost column,
and lock requests are listed in the first row. The intersection of a and lock requests are listed in the first row. The intersection of a
row and column gives the result of a lock request. For example, if a row and column gives the result of a lock request. For example, if a
shared lock is held on a resource, and an exclusive lock is shared lock is held on a resource, and an exclusive lock is
requested, the table entry is "false", indicating the lock must not requested, the table entry is "false", indicating the lock must not
be granted. be granted.
8.10.7. Status Codes 9.10.6. LOCK Responses
200 (OK) - The lock request succeeded and the value of the In addition to the general status codes possible, the following
lockdiscovery property is included in the body. status codes have specific applicability to LOCK:
412 (Precondition Failed) - The included lock token was not 200 (OK) - The LOCK request succeeded and the value of the DAV:
enforceable on this resource or the server could not satisfy the lockdiscovery property is included in the response body.
request in the lockinfo XML element.
423 (Locked) - The resource is locked, so the method has been 201 (Created) - The LOCK request was to an unmapped URL, the request
rejected. succeeded and resulted in the creation of a new resource, and the
value of the DAV:lockdiscovery property is included in the response
body.
8.10.8. Example - Simple Lock Request 409 (Conflict) - A resource cannot be created at the destination
until one or more intermediate collections have been created. The
server MUST NOT create those intermediate collections automatically.
423 (Locked), potentially with 'no-conflicting-lock' precondition
code - There is already a lock on the resource which is not
compatible with the requested lock (see lock compatibility table
above).
412 (Precondition Failed), with 'lock-token-matches-request-uri'
precondition code - The LOCK request was made with a If header,
indicating that the client wishes to refresh the given lock.
However, the Request-URI did not fall within the scope of the lock
identified by the token. The lock may have a scope that does not
include the Request-URI, or the lock could have disappeared, or the
token may be invalid.
9.10.7. Example - Simple Lock Request
>>Request >>Request
LOCK /workspace/webdav/proposal.doc HTTP/1.1 LOCK /workspace/webdav/proposal.doc HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Timeout: Infinite, Second-4100000000 Timeout: Infinite, Second-4100000000
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
Authorization: Digest username="ejw", Authorization: Digest username="ejw",
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:lockinfo xmlns:D='DAV:'> <D:lockinfo xmlns:D='DAV:'>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:owner> <D:owner>
<D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
</D:owner> </D:owner>
</D:lockinfo> </D:lockinfo>
>>Response >>Response
HTTP/1.1 200 OK HTTP/1.1 200 OK
Content-Type: text/xml; charset="utf-8" Lock-Token: <urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>
Content-Length: xxxx Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:prop xmlns:D="DAV:"> <D:prop xmlns:D="DAV:">
<D:lockdiscovery> <D:lockdiscovery>
<D:activelock> <D:activelock>
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:depth>Infinity</D:depth> <D:depth>infinity</D:depth>
<D:owner> <D:owner>
<D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
http://www.ics.uci.edu/~ejw/contact.html </D:owner>
</D:href> <D:timeout>Second-604800</D:timeout>
</D:owner> <D:locktoken>
<D:timeout>Second-604800</D:timeout> <D:href
<D:locktoken> >urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4</D:href>
<D:href> </D:locktoken>
opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4 <D:lockroot>
</D:href> <D:href
</D:locktoken> >http://example.com/workspace/webdav/proposal.doc</D:href>
</D:activelock> </D:lockroot>
</D:lockdiscovery> </D:activelock>
</D:prop> </D:lockdiscovery>
</D:prop>
This example shows the successful creation of an exclusive write lock This example shows the successful creation of an exclusive write lock
on resource http://webdav.sb.aol.com/workspace/webdav/proposal.doc. on resource http://example.com/workspace/webdav/proposal.doc. The
The resource http://www.ics.uci.edu/~ejw/contact.html contains resource http://example.org/~ejw/contact.html contains contact
contact information for the owner of the lock. The server has an information for the creator of the lock. The server has an activity-
activity-based timeout policy in place on this resource, which causes based timeout policy in place on this resource, which causes the lock
the lock to automatically be removed after 1 week (604800 seconds). to automatically be removed after 1 week (604800 seconds). Note that
Note that the nonce, response, and opaque fields have not been the nonce, response, and opaque fields have not been calculated in
calculated in the Authorization request header. the Authorization request header.
8.10.9. Example - Refreshing a Write Lock 9.10.8. Example - Refreshing a Write Lock
>>Request >>Request
LOCK /workspace/webdav/proposal.doc HTTP/1.1 LOCK /workspace/webdav/proposal.doc HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Timeout: Infinite, Second-4100000000 Timeout: Infinite, Second-4100000000
If: (<opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>) If: (<urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>)
Authorization: Digest username="ejw", Authorization: Digest username="ejw",
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
>>Response >>Response
HTTP/1.1 200 OK HTTP/1.1 200 OK
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:prop xmlns:D="DAV:"> <D:prop xmlns:D="DAV:">
<D:lockdiscovery> <D:lockdiscovery>
<D:activelock> <D:activelock>
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:depth>Infinity</D:depth> <D:depth>infinity</D:depth>
<D:owner> <D:owner>
<D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
http://www.ics.uci.edu/~ejw/contact.html </D:owner>
</D:href> <D:timeout>Second-604800</D:timeout>
</D:owner> <D:locktoken>
<D:timeout>Second-604800</D:timeout> <D:href
<D:locktoken> >urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4</D:href>
<D:href> </D:locktoken>
opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4 <D:lockroot>
</D:href> <D:href
</D:locktoken> >http://example.com/workspace/webdav/proposal.doc</D:href>
</D:activelock> </D:lockroot>
</D:lockdiscovery> </D:activelock>
</D:prop> </D:lockdiscovery>
</D:prop>
This request would refresh the lock, resetting any time outs. Notice This request would refresh the lock, attempting to reset the timeout
that the client asked for an infinite time out but the server choose to the new value specified in the timeout header. Notice that the
to ignore the request. In this example, the nonce, response, and client asked for an infinite time out but the server choose to ignore
opaque fields have not been calculated in the Authorization request the request. In this example, the nonce, response, and opaque fields
header. have not been calculated in the Authorization request header.
8.10.10. Example - Multi-Resource Lock Request 9.10.9. Example - Multi-Resource Lock Request
>>Request >>Request
LOCK /webdav/ HTTP/1.1 LOCK /webdav/ HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Timeout: Infinite, Second-4100000000 Timeout: Infinite, Second-4100000000
Depth: infinity Depth: infinity
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
Authorization: Digest username="ejw", Authorization: Digest username="ejw",
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:lockinfo xmlns:D="DAV:"> <D:lockinfo xmlns:D="DAV:">
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:owner> <D:owner>
<D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
</D:owner> </D:owner>
</D:lockinfo> </D:lockinfo>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"> <D:multistatus xmlns:D="DAV:">
<D:response> <D:response>
<D:href>http://webdav.sb.aol.com/webdav/secret</D:href> <D:href>http://example.com/webdav/secret</D:href>
<D:status>HTTP/1.1 403 Forbidden</D:status> <D:status>HTTP/1.1 403 Forbidden</D:status>
</D:response> </D:response>
<D:response> <D:response>
<D:href>http://webdav.sb.aol.com/webdav/</D:href> <D:href>http://example.com/webdav/</D:href>
<D:propstat> <D:status>HTTP/1.1 424 Failed Dependency</D:status>
<D:prop><D:lockdiscovery/></D:prop> </D:response>
<D:status>HTTP/1.1 424 Failed Dependency</D:status> </D:multistatus>
</D:propstat>
</D:response>
</D:multistatus>
This example shows a request for an exclusive write lock on a This example shows a request for an exclusive write lock on a
collection and all its children. In this request, the client has collection and all its children. In this request, the client has
specified that it desires an infinite length lock, if available, specified that it desires an infinite length lock, if available,
otherwise a timeout of 4.1 billion seconds, if available. The otherwise a timeout of 4.1 billion seconds, if available. The
request entity body contains the contact information for the request entity body contains the contact information for the
principal taking out the lock, in this case a web page URL. principal taking out the lock, in this case a web page URL.
The error is a 403 (Forbidden) response on the resource The error is a 403 (Forbidden) response on the resource
http://webdav.sb.aol.com/webdav/secret. Because this resource could http://example.com/webdav/secret. Because this resource could not be
not be locked, none of the resources were locked. Note also that the locked, none of the resources were locked. Note also that the a
lockdiscovery property for the Request-URI has been included as 'response' element for the Request-URI itself has been included as
required. In this example the lockdiscovery property is empty which required.
means that there are no outstanding locks on the resource.
In this example, the nonce, response, and opaque fields have not been In this example, the nonce, response, and opaque fields have not been
calculated in the Authorization request header. calculated in the Authorization request header.
8.11. UNLOCK Method 9.11. UNLOCK Method
The UNLOCK method removes the lock identified by the lock token in The UNLOCK method removes the lock identified by the lock token in
the Lock-Token request header from the Request-URI, and all other the Lock-Token request header. The Request-URI MUST identify a
resources included in the lock. If all resources which have been resource within the scope of the lock.
locked under the submitted lock token can not be unlocked then the
UNLOCK request MUST fail. Note that use of Lock-Token header to provide the lock token is not
consistent with other state-changing methods which all require an If
header with the lock token. Thus, the If header is not needed to
provide the lock token. Naturally when the If header is present it
has its normal meaning as a conditional header.
For a successful response to this method, the server MUST delete the
lock entirely.
If all resources which have been locked under the submitted lock
token can not be unlocked then the UNLOCK request MUST fail.
A successful response to an UNLOCK method does not mean that the
resource is necessarily unlocked. It means that the specific lock
corresponding to the specified token no longer exists.
Any DAV compliant resource which supports the LOCK method MUST Any DAV compliant resource which supports the LOCK method MUST
support the UNLOCK method. support the UNLOCK method.
8.11.1. Example - UNLOCK This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
9.11.1. Status Codes
In addition to the general status codes possible, the following
status codes have specific applicability to UNLOCK:
204 (No Content) - Normal success response (rather than 200 OK, since
200 OK would imply a response body, and an UNLOCK success response
does not normally contain a body)
400 (Bad Request) - No lock token was provided.
403 (Forbidden) - The currently authenticated principal does not have
permission to remove the lock.
409 (Conflict), with 'lock-token-matches-request-uri' precondition -
The resource was not locked, or the request was made to a Request-URI
that was not within the scope of the lock.
9.11.2. Example - UNLOCK
>>Request >>Request
UNLOCK /workspace/webdav/info.doc HTTP/1.1 UNLOCK /workspace/webdav/info.doc HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Lock-Token: <opaquelocktoken:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7> Lock-Token: <urn:uuid:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7>
Authorization: Digest username="ejw", Authorization: Digest username="ejw"
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
>>Response >>Response
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
In this example, the lock identified by the lock token In this example, the lock identified by the lock token
"opaquelocktoken:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7" is "urn:uuid:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7" is successfully
successfully removed from the resource removed from the resource
http://webdav.sb.aol.com/workspace/webdav/info.doc. If this lock http://example.com/workspace/webdav/info.doc. If this lock included
included more than just one resource, the lock is removed from all more than just one resource, the lock is removed from all resources
resources included in the lock. The 204 (No Content) status code is included in the lock.
used instead of 200 (OK) because there is no response entity body.
In this example, the nonce, response, and opaque fields have not been In this example, the nonce, response, and opaque fields have not been
calculated in the Authorization request header. calculated in the Authorization request header.
9. HTTP Headers for Distributed Authoring 10. HTTP Headers for Distributed Authoring
9.1. DAV Header All DAV headers follow the same basic formatting rules as HTTP
headers. This includes rules like line continuation and how to
combine (or separate) multiple instances of the same header using
commas.
DAV = "DAV" ":" "1" ["," "2"] ["," 1#extend] WebDAV adds two new conditional headers to the set defined in HTTP:
the If and Overwrite headers.
This header indicates that the resource supports the DAV schema and 10.1. DAV Header
protocol as specified. All DAV compliant resources MUST return the
DAV header on all OPTIONS responses.
The value is a list of all compliance classes that the resource DAV = "DAV" ":" #( compliance-class )
supports. Note that above a comma has already been added to the 2. compliance-class = ( "1" | "2" | "3" | extend )
This is because a resource can not be level 2 compliant unless it is extend = Coded-URL | token
also level 1 compliant. Please refer to Section 15 for more details. Coded-URL = "<" absolute-URI ">"
In general, however, support for one compliance class does not entail ; No linear white space (LWS) allowed in Coded-URL
support for any other. ; absolute-URI is defined in RFC3986
9.2. Depth Header This general-header appearing in the response indicates that the
resource supports the DAV schema and protocol as specified. All DAV
compliant resources MUST return the DAV header with compliance-class
"1" on all OPTIONS responses. In cases where WebDAV is only
supported in part of the server namespace, an OPTIONS request to non-
WebDAV resources (including "/") SHOULD NOT advertise WebDAV support.
The value is a comma-separated list of all compliance class
identifiers that the resource supports. Class identifiers may be
Coded-URLs or tokens (as defined by [RFC2616]). Identifiers can
appear in any order. Identifiers that are standardized through the
IETF RFC process are tokens, but other identifiers SHOULD be Coded-
URLs to encourage uniqueness.
A resource must show class 1 compliance if it shows class 2 or 3
compliance. In general, support for one compliance class does not
entail support for any other, and in particular, support for
compliance class 3 does not require support for compliance class 2.
Please refer to Section 18 for more details on compliance classes
defined in this specification.
Note that many WebDAV servers do not advertise WebDAV support in
response to "OPTIONS *".
As a request header, this header allows the client to advertise
compliance with named features when the server needs that
information. Clients SHOULD NOT send this header unless a standards
track specification requires it. Any extension that makes use of
this as a request header will need to carefully consider caching
implications.
10.2. Depth Header
Depth = "Depth" ":" ("0" | "1" | "infinity") Depth = "Depth" ":" ("0" | "1" | "infinity")
The Depth header is used with methods executed on resources which The Depth request header is used with methods executed on resources
could potentially have internal members to indicate whether the which could potentially have internal members to indicate whether the
method is to be applied only to the resource ("Depth: 0"), to the method is to be applied only to the resource ("Depth: 0"), to the
resource and its immediate children, ("Depth: 1"), or the resource resource and its internal members only, ("Depth: 1"), or the resource
and all its progeny ("Depth: infinity"). and all its members ("Depth: infinity").
The Depth header is only supported if a method's definition The Depth header is only supported if a method's definition
explicitly provides for such support. explicitly provides for such support.
The following rules are the default behavior for any method that The following rules are the default behavior for any method that
supports the Depth header. A method may override these defaults by supports the Depth header. A method may override these defaults by
defining different behavior in its definition. defining different behavior in its definition.
Methods which support the Depth header may choose not to support all Methods which support the Depth header may choose not to support all
of the header's values and may define, on a case by case basis, the of the header's values and may define, on a case by case basis, the
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hierarchies in any particular order or on the execution being atomic hierarchies in any particular order or on the execution being atomic
unless the particular method explicitly provides such guarantees. unless the particular method explicitly provides such guarantees.
Upon execution, a method with a Depth header will perform as much of Upon execution, a method with a Depth header will perform as much of
its assigned task as possible and then return a response specifying its assigned task as possible and then return a response specifying
what it was able to accomplish and what it failed to do. what it was able to accomplish and what it failed to do.
So, for example, an attempt to COPY a hierarchy may result in some of So, for example, an attempt to COPY a hierarchy may result in some of
the members being copied and some not. the members being copied and some not.
Any headers on a method that has a defined interaction with the Depth By default, the Depth header does not interact with other headers.
header MUST be applied to all resources in the scope of the method That is, each header on a request with a Depth header MUST be applied
except where alternative behavior is explicitly defined. For only to the Request-URI if it applies to any resource, unless
example, an If-Match header will have its value applied against every specific Depth behavior is defined for that header.
resource in the method's scope and will cause the method to fail if
the header fails to match.
If a resource, source or destination, within the scope of the method If a resource, source or destination, within the scope of the method
with a Depth header is locked in such a way as to prevent the with a Depth header is locked in such a way as to prevent the
successful execution of the method, then the lock token for that successful execution of the method, then the lock token for that
resource MUST be submitted with the request in the If request header. resource MUST be submitted with the request in the If request header.
The Depth header only specifies the behavior of the method with The Depth header only specifies the behavior of the method with
regards to internal children. If a resource does not have internal regards to internal members. If a resource does not have internal
children then the Depth header MUST be ignored. members then the Depth header MUST be ignored.
Please note, however, that it is always an error to submit a value 10.3. Destination Header
for the Depth header that is not allowed by the method's definition.
Thus submitting a "Depth: 1" on a COPY, even if the resource does not
have internal members, will result in a 400 (Bad Request). The
method should fail not because the resource doesn't have internal
members, but because of the illegal value in the header.
9.3. Destination Header The Destination request header specifies the URI which identifies a
destination resource for methods such as COPY and MOVE, which take
two URIs as parameters.
Destination = "Destination" ":" absoluteURI Destination = "Destination" ":" Simple-ref
The Destination header specifies the URI which identifies a If the Destination value is an absolute-URI (Section 4.3 of
destination resource for methods such as COPY and MOVE, which take [RFC3986]), it may name a different server (or different port or
two URIs as parameters. Note that the absoluteURI production is scheme). If the source server cannot attempt a copy to the remote
defined in [RFC2396]. server, it MUST fail the request. Note that copying and moving
resources to remote servers is not fully defined in this
specification (e.g. specific error conditions).
9.4. If Header If the Destination value is too long or otherwise unacceptable, the
server SHOULD return 400 (Bad Request), ideally with helpful
information in an error body.
If = "If" ":" ( 1*No-tag-list | 1*Tagged-list) 10.4. If Header
No-tag-list = List
Tagged-list = Resource 1*List
Resource = Coded-URL
List = "(" 1*(["Not"](State-token | "[" entity-tag "]")) ")"
State-token = Coded-URL
Coded-URL = "<" absoluteURI ">"
The If header is intended to have similar functionality to the If- The If request header is intended to have similar functionality to
Match header defined in section 14.25 of [RFC2068]. However the If the If-Match header defined in Section 14.24 of [RFC2616]. However
header is intended for use with any URI which represents state the If header handles any state token as well as ETags. A typical
information, referred to as a state token, about a resource as well example of a state token is a lock token, and lock tokens are the
as ETags. A typical example of a state token is a lock token, and only state tokens defined in this specification.
lock tokens are the only state tokens defined in this specification.
All DAV compliant resources MUST honor the If header. 10.4.1. Purpose
The If header's purpose is to describe a series of state lists. If The If header has two distinct purposes:
the state of the resource to which the header is applied does not
match any of the specified state lists then the request MUST fail
with a 412 (Precondition Failed). If one of the described state
lists matches the state of the resource then the request may succeed.
Note that the absoluteURI production is defined in [RFC2396]. o The first purpose is to make a request conditional by supplying a
series of state lists with conditions that match tokens and ETags
to specific resource. If this header is evaluated and all state
lists fail, then the request MUST fail with a 412 (Precondition
Failed) status. On the other hand, the request can succeed only
if one of the described state lists succeeds. The success
criteria for state lists and matching functions are defined in
Section 10.4.3 and Section 10.4.4.
9.4.1. No-tag-list Production o Additionally, the mere fact that a state token appears in an If
header means that it has been "submitted" with the request. In
general, this is used to indicate that the client has knowledge of
that state token. The semantics for submitting a state token
depend on its type (for lock tokens, please refer to Section 6).
The No-tag-list production describes a series of state tokens and Note that these two purposes need to be treated distinctly: a state
ETags. If multiple No-tag-list productions are used then one only token counts as being submitted independently of whether the server
needs to match the state of the resource for the method to be allowed actually has evaluated the state list it appears in, and also
to continue. independently of whether the condition it expressed was found to be
true or not.
If a method, due to the presence of a Depth or Destination header, is 10.4.2. Syntax
applied to multiple resources then the No-tag-list production MUST be
applied to each resource the method is applied to.
9.4.1.1. Example - No-tag-list If Header If = "If" ":" ( 1*No-tag-list | 1*Tagged-list )
If: (<locktoken:a-write-lock-token> ["I am an ETag"]) (["I am another No-tag-list = List
ETag"]) Tagged-list = Resource-Tag 1*List
The previous header would require that any resources within the scope List = "(" 1*Condition ")"
of the method must either be locked with the specified lock token and Condition = ["Not"] (State-token | "[" entity-tag "]")
in the state identified by the "I am an ETag" ETag or in the state ; entity-tag: see Section 3.11 of [RFC2616]
identified by the second ETag "I am another ETag". To put the matter ; No LWS allowed between "[", entity-tag and "]"
more plainly one can think of the previous If header as being in the
form (or (and <locktoken:a-write-lock-token> ["I am an ETag"]) (and
["I am another ETag"])).
9.4.2. Tagged-list Production State-token = Coded-URL
The tagged-list production scopes a list production. That is, it Resource-Tag = "<" Simple-ref ">"
specifies that the lists following the resource specification only ; Simple-ref: see Section 8.3
apply to the specified resource. The scope of the resource ; No LWS allowed in Resource-Tag
production begins with the list production immediately following the
resource production and ends with the next resource production, if
any.
When the If header is applied to a particular resource, the Tagged- The syntax distinguishes between untagged lists ("No-tag-list") and
list productions MUST be searched to determine if any of the listed tagged lists ("Tagged-list"). Untagged lists apply to the resource
resources match the operand resource(s) for the current method. If identified by the Request-URI, while tagged lists apply to the
none of the resource productions match the current resource then the resource identified by the preceding Resource-Tag.
header MUST be ignored. If one of the resource productions does
match the name of the resource under consideration then the list
productions following the resource production MUST be applied to the
resource in the manner specified in the previous section.
The same URI MUST NOT appear more than once in a resource production A Resource-Tag applies to all subsequent Lists, up to the next
in an If header. Resource-Tag.
9.4.2.1. Example - Tagged List If header Note that the two list types cannot be mixed within an If header.
This is not a functional restriction because the No-tag-list syntax
is just a shorthand notation for a Tagged-list production with a
Resource-Tag referring to the Request-URI.
COPY /resource1 HTTP/1.1 Each List consists of one or more Conditions. Each Condition is
Host: www.foo.bar defined in terms of an entity-tag or state-token, potentially negated
Destination: http://www.foo.bar/resource2 by the prefix "Not".
If: <http://www.foo.bar/resource1> (<locktoken:a-write-lock-token>
[W/"A weak ETag"]) (["strong ETag"])
<http://www.bar.bar/random>(["another strong ETag"])
In this example http://www.foo.bar/resource1 is being copied to Note that the If header syntax does not allow multiple instances of
http://www.foo.bar/resource2. When the method is first applied to If headers in a single request. However, the HTTP header syntax
http://www.foo.bar/resource1, resource1 must be in the state allows extending single header values across multiple lines, by
specified by "(<locktoken:a-write-lock-token> [W/"A weak ETag"]) inserting a line break followed by whitespace (see [RFC2616], Section
(["strong ETag"])", that is, it either must be locked with a lock 4.2).
token of "locktoken:a-write-lock-token" and have a weak entity tag
W/"A weak ETag" or it must have a strong entity tag "strong ETag".
That is the only success condition since the resource 10.4.3. List Evaluation
http://www.bar.bar/random never has the method applied to it (the
only other resource listed in the If header) and
http://www.foo.bar/resource2 is not listed in the If header.
9.4.3. not Production A Condition that consists of a single entity-tag or state-token
evaluates to true if the resource matches the described state (where
the individual matching functions are defined below in
Section 10.4.4). Prefixing it with "Not" reverses the result of the
evaluation (thus, the "Not" applies only to the subsequent entity-tag
or state-token).
Every state token or ETag is either current, and hence describes the Each List production describes a series of conditions. The whole
state of a resource, or is not current, and does not describe the list evaluates to true if and only if each condition evaluates to
state of a resource. The boolean operation of matching a state token true (that is, the list represents a logical conjunction of
or ETag to the current state of a resource thus resolves to a true or Conditions).
false value. The not production is used to reverse that value. The
scope of the not production is the state-token or entity-tag
immediately following it.
If: (Not <locktoken:write1> <locktoken:write2>) Each No-tag-list and Tagged-list production may contain one or more
Lists. They evaluate to true if and only if any of the contained
lists evaluates to true (that is, if there's more than one List, that
List sequence represents a logical disjunction of the Lists).
When submitted with a request, this If header requires that all Finally, the whole If header evaluates to true if and only if at
operand resources must not be locked with locktoken:write1 and must least one of the No-tag-list or Tagged-list productions evaluates to
be locked with locktoken:write2. true. If the header evaluates to false, the server MUST reject the
request with a 412 (Precondition Failed) status. Otherwise,
execution of the request can proceed as if the header wasn't present.
9.4.4. Matching Function 10.4.4. Matching State Tokens and ETags
When performing If header processing, the definition of a matching When performing If header processing, the definition of a matching
state token or entity tag is as follows. state token or entity tag is as follows:
Identifying a resource: The resource is identified by the URI along
with the token, in tagged list production, or by the Request-URI in
untagged list production.
Matching entity tag: Where the entity tag matches an entity tag Matching entity tag: Where the entity tag matches an entity tag
associated with that resource. associated with the identified resource. Servers MUST use either the
weak or the strong comparison function defined in Section 13.3.3 of
[RFC2616].
Matching state token: Where there is an exact match between the state Matching state token: Where there is an exact match between the state
token in the If header and any state token on the resource. token in the If header and any state token on the identified
resource. A lock state token is considered to match if the resource
is anywhere in the scope of the lock.
9.4.5. If Header and Non-DAV Compliant Proxies Handling unmapped URLs: for both ETags and state tokens, treat as if
the URL identified a resource that exists but does not have the
specified state.
Non-DAV compliant proxies will not honor the If header, since they 10.4.5. If Header and Non-DAV Aware Proxies
will not understand the If header, and HTTP requires non-understood
Non-DAV aware proxies will not honor the If header, since they will
not understand the If header, and HTTP requires non-understood
headers to be ignored. When communicating with HTTP/1.1 proxies, the headers to be ignored. When communicating with HTTP/1.1 proxies, the
"Cache-Control: no-cache" request header MUST be used so as to client MUST use the "Cache-Control: no-cache" request header so as to
prevent the proxy from improperly trying to service the request from prevent the proxy from improperly trying to service the request from
its cache. When dealing with HTTP/1.0 proxies the "Pragma: no-cache" its cache. When dealing with HTTP/1.0 proxies the "Pragma: no-cache"
request header MUST be used for the same reason. request header MUST be used for the same reason.
9.5. Lock-Token Header As in general clients may not be able to reliably detect non-DAV
aware intermediates, they are advised to always prevent caching using
the request directives mentioned above.
10.4.6. Example - No-tag Production
If: (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
["I am an ETag"])
(["I am another ETag"])
The previous header would require that the resource identified in the
Request-URI be locked with the specified lock token and be in the
state identified by the "I am an ETag" ETag or in the state
identified by the second ETag "I am another ETag".
To put the matter more plainly one can think of the previous If
header as expressing the condition below:
(
is-locked-with(urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2) AND
matches-etag("I am an ETag")
)
OR
(
matches-etag("I am another ETag")
)
10.4.7. Example - using "Not" with No-tag Production
If: (Not <urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
<urn:uuid:58f202ac-22cf-11d1-b12d-002035b29092>)
This If header requires that the resource must not be locked with a
lock having the lock token
urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2 and must be locked by a
lock with the lock token
urn:uuid:58f202ac-22cf-11d1-b12d-002035b29092.
10.4.8. Example - causing a Condition to always evaluate to True
There may be cases where a client wishes to submit state tokens, but
doesn't want the request to fail just because the state token isn't
current anymore. One simple way to do this is to include a Condition
that is known to always evaluate to true, such as in:
If: (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>)
(Not <DAV:no-lock>)
"DAV:no-lock" is known to never represent a current lock token, as
lock tokens are assigned by the server, following the uniqueness
requirements described in Section 6.5, therefore in particular
exclude URIs in the "DAV:" scheme. Thus, by applying "Not" to a
known not to be current state token, the Condition always evaluates
to true. Consequently, the whole If header will always evaluate to
true, and the lock token
urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2 will be submitted in
any case.
10.4.9. Example - Tagged List If header in COPY
>>Request
COPY /resource1 HTTP/1.1
Host: www.example.com
Destination: /resource2
If: </resource1>
(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
[W/"A weak ETag"]) (["strong ETag"])
In this example http://www.example.com/resource1 is being copied to
http://www.example.com/resource2. When the method is first applied
to http://www.example.com/resource1, resource1 must be in the state
specified by "(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2> [W/"A
weak ETag"]) (["strong ETag"])", that is, it either must be locked
with a lock token of "urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2"
and have a weak entity tag W/"A weak ETag" or it must have a strong
entity tag "strong ETag".
10.4.10. Example - Matching lock tokens with collection locks
DELETE /specs/rfc2518.txt HTTP/1.1
Host: www.example.com
If: <http://www.example.com/specs/>
(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>)
For this example, the lock token must be compared to the identified
resource, which is the 'specs' collection identified by the URL in
the tagged list production. If the 'specs' collection is not locked
by a lock with the specified lock token, the request MUST fail.
Otherwise, this request could succeed, because the If header
evaluates to true, and because the lock token for the lock affecting
the affected resource has been submitted.
10.4.11. Example - Matching ETags on unmapped URLs
Consider a collection "/specs" that does not contain the member
"/specs/rfc2518.doc". In this case, the If header
If: </specs/rfc2518.doc> (["4217"])
will evaluate to false (the URI isn't mapped, thus the resource
identified by the URI doesn't have an entity matching the ETag
"4217").
On the other hand, an If header of
If: </specs/rfc2518.doc> (Not ["4217"])
will consequently evaluate to true.
Note that as defined above in Section 10.4.4, the same considerations
apply to matching state tokens.
10.5. Lock-Token Header
Lock-Token = "Lock-Token" ":" Coded-URL Lock-Token = "Lock-Token" ":" Coded-URL
The Lock-Token request header is used with the UNLOCK method to The Lock-Token request header is used with the UNLOCK method to
identify the lock to be removed. The lock token in the Lock-Token identify the lock to be removed. The lock token in the Lock-Token
request header MUST identify a lock that contains the resource request header MUST identify a lock that contains the resource
identified by Request-URI as a member. identified by Request-URI as a member.
The Lock-Token response header is used with the LOCK method to The Lock-Token response header is used with the LOCK method to
indicate the lock token created as a result of a successful LOCK indicate the lock token created as a result of a successful LOCK
request to create a new lock. request to create a new lock.
9.6. Overwrite Header 10.6. Overwrite Header
Overwrite = "Overwrite" ":" ("T" | "F") Overwrite = "Overwrite" ":" ("T" | "F")
The Overwrite header specifies whether the server should overwrite The Overwrite request header specifies whether the server should
the state of a non-null destination resource during a COPY or MOVE. overwrite a resource mapped to the destination URL during a COPY or
A value of "F" states that the server must not perform the COPY or MOVE. A value of "F" states that the server must not perform the
MOVE operation if the state of the destination resource is non-null. COPY or MOVE operation if the destination URL does map to a resource.
If the overwrite header is not included in a COPY or MOVE request If the overwrite header is not included in a COPY or MOVE request
then the resource MUST treat the request as if it has an overwrite then the resource MUST treat the request as if it has an overwrite
header of value "T". While the Overwrite header appears to duplicate header of value "T". While the Overwrite header appears to duplicate
the functionality of the If-Match: * header of HTTP/1.1, If-Match the functionality of using a "If-Match: *" header (see [RFC2616]),
applies only to the Request-URI, and not to the Destination of a COPY If-Match applies only to the Request-URI, and not to the Destination
or MOVE. of a COPY or MOVE.
If a COPY or MOVE is not performed due to the value of the Overwrite If a COPY or MOVE is not performed due to the value of the Overwrite
header, the method MUST fail with a 412 (Precondition Failed) status header, the method MUST fail with a 412 (Precondition Failed) status
code. code. The server MUST do authorization checks before checking this
or any conditional header.
All DAV compliant resources MUST support the Overwrite header. All DAV compliant resources MUST support the Overwrite header.
9.7. Status-URI Response Header 10.7. Timeout Request Header
The Status-URI response header may be used with the 102 (Processing)
status code to inform the client as to the status of a method.
Status-URI = "Status-URI" ":" *(Status-Code Coded-URL) ; Status-Code
is defined in Section 6.1.1 of [RFC2068]
The URIs listed in the header are source resources which have been
affected by the outstanding method. The status code indicates the
resolution of the method on the identified resource. So, for
example, if a MOVE method on a collection is outstanding and a 102
(Processing) response with a Status-URI response header is returned,
the included URIs will indicate resources that have had move
attempted on them and what the result was.
9.8. Timeout Request Header
TimeOut = "Timeout" ":" 1#TimeType TimeOut = "Timeout" ":" 1#TimeType
TimeType = ("Second-" DAVTimeOutVal | "Infinite" | Other) TimeType = ("Second-" DAVTimeOutVal | "Infinite")
DAVTimeOutVal = 1*digit ; No LWS allowed within TimeType
Other = "Extend" field-value ; See section 4.2 of [RFC2068] DAVTimeOutVal = 1*DIGIT
Clients may include Timeout headers in their LOCK requests. However,
the server is not required to honor or even consider these requests.
Clients MUST NOT submit a Timeout request header with any method
other than a LOCK method.
A Timeout request header MUST contain at least one TimeType and may
contain multiple TimeType entries. The purpose of listing multiple
TimeType entries is to indicate multiple different values and value
types that are acceptable to the client. The client lists the
TimeType entries in order of preference.
Timeout response values MUST use a Second value, Infinite, or a Clients MAY include Timeout request headers in their LOCK requests.
TimeType the client has indicated familiarity with. The server may However, the server is not required to honor or even consider these
assume a client is familiar with any TimeType submitted in a Timeout requests. Clients MUST NOT submit a Timeout request header with any
header. method other than a LOCK method.
The "Second" TimeType specifies the number of seconds that will The "Second" TimeType specifies the number of seconds that will
elapse between granting of the lock at the server, and the automatic elapse between granting of the lock at the server, and the automatic
removal of the lock. The timeout value for TimeType "Second" MUST removal of the lock. The timeout value for TimeType "Second" MUST
NOT be greater than 2^32-1. NOT be greater than 2^32-1.
The timeout counter SHOULD be restarted any time an owner of the lock See Section 6.6 for a description of lock timeout behavior.
sends a method to any member of the lock, including unsupported
methods, or methods which are unsuccessful. However the lock MUST be
refreshed if a refresh LOCK method is successfully received.
If the timeout expires then the lock may be lost. Specifically, if
the server wishes to harvest the lock upon time-out, the server
SHOULD act as if an UNLOCK method was executed by the server on the
resource using the lock token of the timed-out lock, performed with
its override authority. Thus logs should be updated with the
disposition of the lock, notifications should be sent, etc., just as
they would be for an UNLOCK request.
Servers are advised to pay close attention to the values submitted by
clients, as they will be indicative of the type of activity the
client intends to perform. For example, an applet running in a
browser may need to lock a resource, but because of the instability
of the environment within which the applet is running, the applet may
be turned off without warning. As a result, the applet is likely to
ask for a relatively small timeout value so that if the applet dies,
the lock can be quickly harvested. However, a document management
system is likely to ask for an extremely long timeout because its
user may be planning on going off-line.
A client MUST NOT assume that just because the time-out has expired
the lock has been lost.
10. Status Code Extensions to HTTP/1.1 11. Status Code Extensions to HTTP/1.1
The following status codes are added to those defined in HTTP/1.1 The following status codes are added to those defined in HTTP/1.1
[RFC2068]. [RFC2616].
10.1. 102 Processing
The 102 (Processing) status code is an interim response used to
inform the client that the server has accepted the complete request,
but has not yet completed it. This status code SHOULD only be sent
when the server has a reasonable expectation that the request will
take significant time to complete. As guidance, if a method is
taking longer than 20 seconds (a reasonable, but arbitrary value) to
process the server SHOULD return a 102 (Processing) response. The
server MUST send a final response after the request has been
completed.
Methods can potentially take a long period of time to process,
especially methods that support the Depth header. In such cases the
client may time-out the connection while waiting for a response. To
prevent this the server may return a 102 (Processing) status code to
indicate to the client that the server is still processing the
method.
10.2. 207 Multi-Status 11.1. 207 Multi-Status
The 207 (Multi-Status) status code provides status for multiple The 207 (Multi-Status) status code provides status for multiple
independent operations (see Section 11 for more information). independent operations (see Section 13 for more information).
10.3. 422 Unprocessable Entity 11.2. 422 Unprocessable Entity
The 422 (Unprocessable Entity) status code means the server The 422 (Unprocessable Entity) status code means the server
understands the content type of the request entity (hence a understands the content type of the request entity (hence a
415(Unsupported Media Type) status code is inappropriate), and the 415(Unsupported Media Type) status code is inappropriate), and the
syntax of the request entity is correct (thus a 400 (Bad Request) syntax of the request entity is correct (thus a 400 (Bad Request)
status code is inappropriate) but was unable to process the contained status code is inappropriate) but was unable to process the contained
instructions. For example, this error condition may occur if an XML instructions. For example, this error condition may occur if an XML
request body contains well-formed (i.e., syntactically correct), but request body contains well-formed (i.e., syntactically correct), but
semantically erroneous XML instructions. semantically erroneous XML instructions.
10.4. 423 Locked 11.3. 423 Locked
The 423 (Locked) status code means the source or destination resource The 423 (Locked) status code means the source or destination resource
of a method is locked. of a method is locked. This response SHOULD contain an appropriate
precondition or postcondition code, such as 'lock-token-submitted' or
'no-conflicting-lock".
10.5. 424 Failed Dependency 11.4. 424 Failed Dependency
The 424 (Failed Dependency) status code means that the method could The 424 (Failed Dependency) status code means that the method could
not be performed on the resource because the requested action not be performed on the resource because the requested action
depended on another action and that action failed. For example, if a depended on another action and that action failed. For example, if a
command in a PROPPATCH method fails then, at minimum, the rest of the command in a PROPPATCH method fails then, at minimum, the rest of the
commands will also fail with 424 (Failed Dependency). commands will also fail with 424 (Failed Dependency).
10.6. 507 Insufficient Storage 11.5. 507 Insufficient Storage
The 507 (Insufficient Storage) status code means the method could not The 507 (Insufficient Storage) status code means the method could not
be performed on the resource because the server is unable to store be performed on the resource because the server is unable to store
the representation needed to successfully complete the request. This the representation needed to successfully complete the request. This
condition is considered to be temporary. If the request which condition is considered to be temporary. If the request which
received this status code was the result of a user action, the received this status code was the result of a user action, the
request MUST NOT be repeated until it is requested by a separate user request MUST NOT be repeated until it is requested by a separate user
action. action.
11. Multi-Status Response 12. Use of HTTP Status Codes
The default 207 (Multi-Status) response body is a text/xml or These HTTP codes are not redefined, but their use is somewhat
application/xml HTTP entity that contains a single XML element called extended by WebDAV methods and requirements. In general, many HTTP
multistatus, which contains a set of XML elements called response status codes can be used in response to any request, not just in
which contain 200, 300, 400, and 500 series status codes generated cases described in this document. Note also that WebDAV servers are
during the method invocation. 100 series status codes SHOULD NOT be known to use 300-level redirect responses (and early interoperability
recorded in a response XML element. tests found clients unprepared to see those responses). A 300-level
response MUST NOT be used when the server has created a new resource
in response to the request.
12. XML Element Definitions 12.1. 412 Precondition Failed
In the section below, the final line of each section gives the Any request can contain a conditional header defined in HTTP (If-
element type declaration using the format defined in [REC-XML]. The Match, If-Modified-Since, etc.) or the "If" or "Overwrite"
"Value" field, where present, specifies further restrictions on the conditional headers defined in this specification. If the server
allowable contents of the XML element using BNF (i.e., to further evaluates a conditional header, and if that condition fails to hold,
restrict the values of a PCDATA element). then this error code MUST be returned. On the other hand, if the
client did not include a conditional header in the request, then the
server MUST NOT use this status code.
12.1. activelock XML Element 12.2. 414 Request-URI Too Long
Name: activelock This status code is used in HTTP 1.1 only for Request-URIs, not URIs
in other locations.
Namespace: DAV: 13. Multi-Status Response
Purpose: Describes a lock on a resource. A Multi-Status response conveys information about multiple resources
in situations where multiple status codes might be appropriate. The
default Multi-Status response body is a text/xml or application/xml
HTTP entity with a 'multistatus' root element. Further elements
contain 200, 300, 400, and 500 series status codes generated during
the method invocation. 100 series status codes SHOULD NOT be recorded
in a 'response' XML element.
<!ELEMENT activelock (lockscope, locktype, depth, owner?, timeout?, Although '207' is used as the overall response status code, the
locktoken?) > recipient needs to consult the contents of the multistatus response
body for further information about the success or failure of the
method execution. The response MAY be used in success, partial
success and also in failure situations.
12.1.1. depth XML Element The 'multistatus' root element holds zero or more 'response' elements
in any order, each with information about an individual resource.
Each 'response' element MUST have an 'href' element to identify the
resource.
Name: depth A Multi-Status response uses one out of two distinct formats for
representing the status:
Namespace: DAV: 1. A 'status' element as child of the 'response' element indicates
the status of the message execution for the identified resource
as a whole (for instance, see Section 9.6.2). Some method
definitions provide information about specific status codes
clients should be prepared to see in a response. However,
clients MUST be able to handle other status codes, using the
generic rules defined in Section 10 of [RFC2616].
Purpose: The value of the Depth header. 2. For PROPFIND and PROPPATCH, the format has been extended using
the 'propstat' element instead of 'status', providing information
about individual properties of a resource. This format is
specific to PROPFIND and PROPPATCH, and is described in detail in
Section 9.1 and Section 9.2.
Value: "0" | "1" | "infinity" 13.1. Response Headers
<!ELEMENT depth (#PCDATA) > HTTP defines the Location header to indicate a preferred URL for the
resource that was addressed in the Request-URI (e.g. in response to
successful PUT requests or in redirect responses). However, use of
this header creates ambiguity when there are URLs in the body of the
response, as with Multi-Status. Thus, use of the Location header
with the Multi-Status response is intentionally undefined.
12.1.2. locktoken XML Element 13.2. Handling Redirected Child Resources
Name: locktoken Redirect responses (300-303, 305 and 307) defined in HTTP 1.1
normally take a Location header to indicate the new URI for the
single resource redirected from the Request-URI. Multi-Status
responses contain many resource addresses, but the original
definition in [RFC2518] did not have any place for the server to
provide the new URI for redirected resources. This specification
does define a 'location' element for this information (see
Section 14.9). Servers MUST use this new element with redirect
responses in Multi-Status.
Namespace: DAV: Clients encountering redirected resources in Multi-Status MUST NOT
rely on the 'location' element being present with a new URI. If the
element is not present, the client MAY reissue the request to the
individual redirected resource, because the response to that request
can be redirected with a Location header containing the new URI.
Purpose: The lock token associated with a lock. 13.3. Internal Status Codes
Description: The href contains one or more opaque lock token URIs Section 9.2.1, Section 9.1.2, Section 9.6.1, Section 9.8.3 and
which all refer to the same lock (i.e., the OpaqueLockToken-URI Section 9.9.2 define various status codes used in Multi-Status
production in Section 6.4). responses. This specification does not define the meaning of other
status codes that could appear in these responses.
<!ELEMENT locktoken (href+) > 14. XML Element Definitions
12.1.3. timeout XML Element In this section, the final line of each section gives the element
type declaration using the format defined in [REC-XML]. The "Value"
field, where present, specifies further restrictions on the allowable
contents of the XML element using BNF (i.e., to further restrict the
values of a PCDATA element). Note that all of the elements defined
here may be extended according to the rules defined in Section 17.
All elements defined here are in the "DAV:" namespace.
Name: timeout 14.1. activelock XML Element
Namespace: DAV: Name: activelock
Purpose: The timeout associated with a lock Purpose: Describes a lock on a resource.
Value: TimeType ;Defined in Section 9.8 <!ELEMENT activelock (lockscope, locktype, depth, owner?, timeout?,
locktoken?, lockroot)>
<!ELEMENT timeout (#PCDATA) > 14.2. allprop XML Element
12.2. collection XML Element Name: allprop
Name: collection Purpose: Specifies that all names and values of dead properties and
the live properties defined by this document existing on the
resource are to be returned.
Namespace: DAV: <!ELEMENT allprop EMPTY >
Purpose: Identifies the associated resource as a collection. The 14.3. collection XML Element
resourcetype property of a collection resource MUST have this
value.
<!ELEMENT collection EMPTY > Name: collection
12.3. href XML Element Purpose: Identifies the associated resource as a collection. The
DAV:resourcetype property of a collection resource MUST contain
this element. It is normally empty but extensions may add sub-
elements.
Name: href <!ELEMENT collection EMPTY >
Namespace: DAV:
Purpose: Identifies the content of the element as a URI. 14.4. depth XML Element
Value: URI ; See section 3.2.1 of [RFC2068] Name: depth
Purpose: Used for representing depth values in XML content (e.g. in
lock information).
<!ELEMENT href (#PCDATA)> Value: "0" | "1" | "infinity"
12.4. link XML Element <!ELEMENT depth (#PCDATA) >
Name: link 14.5. error XML Element
Namespace: DAV: Name: error
Purpose: Identifies the property as a link and contains the source Purpose: Error responses, particularly 403 Forbidden and 409
and destination of that link. Conflict, sometimes need more information to indicate what went
wrong. In these cases, servers MAY return an XML response body
with a document element of 'error', containing child elements
identifying particular condition codes.
Description: The link XML element is used to provide the sources and Description: Contains at least one XML element, and MUST NOT
destinations of a link. The name of the property containing the contain text or mixed content. Any element that is a child of the
link XML element provides the type of the link. Link is a multi- 'error' element is considered to be a precondition or
valued element, so multiple links may be used together to indicate postcondition code. Unrecognized elements MUST be ignored.
multiple links with the same type. The values in the href XML
elements inside the src and dst XML elements of the link XML
element MUST NOT be rejected if they point to resources which do
not exist.
<!ELEMENT link (src+, dst+) > <!ELEMENT error ANY >
12.4.1. dst XML Element 14.6. exclusive XML Element
Name: dst Name: exclusive
Namespace: DAV: Purpose: Specifies an exclusive lock.
Purpose: Indicates the destination of a link <!ELEMENT exclusive EMPTY >
Value: URI 14.7. href XML Element
<!ELEMENT dst (#PCDATA) > Name: href
12.4.2. src XML Element Purpose: MUST contain a URI or a relative reference.
Name: src
Namespace: DAV: Description: There may be limits on the value of 'href' depending
on the context of its use. Refer to the specification text where
'href' is used to see what limitations apply in each case.
Purpose: Indicates the source of a link. Value: Simple-ref
Value: URI <!ELEMENT href (#PCDATA)>
<!ELEMENT src (#PCDATA) > 14.8. include XML Element
12.5. lockentry XML Element Name: include
Name: lockentry Purpose: Any child element represents the name of a property to be
included in the PROPFIND response. All elements inside an
'include' XML element MUST define properties related to the
resource, although possible property names are in no way limited
to those property names defined in this document or other
standards. This element MUST NOT contain text or mixed content.
Namespace: DAV: <!ELEMENT include ANY >
Purpose: Defines the types of locks that can be used with the 14.9. location XML Element
resource.
<!ELEMENT lockentry (lockscope, locktype) > Name: location
12.6. lockinfo XML Element Purpose: HTTP defines the "Location" header (see [RFC2616], Section
14.30) for use with some status codes (such as 201 and the 300
series codes). When these codes are used inside a 'multistatus'
element, the 'location' element can be used to provide the
accompanying Location header value.
Name: lockinfo Description: Contains a single href element with the same value
that would be used in a Location header.
Namespace: DAV: <!ELEMENT location (href)>
Purpose: The lockinfo XML element is used with a LOCK method to 14.10. lockentry XML Element
Name: lockentry
Purpose: Defines the types of locks that can be used with the
resource.
<!ELEMENT lockentry (lockscope, locktype) >
14.11. lockinfo XML Element
Name: lockinfo
Purpose: The 'lockinfo' XML element is used with a LOCK method to
specify the type of lock the client wishes to have created. specify the type of lock the client wishes to have created.
<!ELEMENT lockinfo (lockscope, locktype, owner?) > <!ELEMENT lockinfo (lockscope, locktype, owner?) >
12.7. lockscope XML Element 14.12. lockroot XML Element
Name: lockscope Name: lockroot
Namespace: DAV: Purpose: Contains the root URL of the lock, which is the URL
through which the resource was addressed in the LOCK request.
Purpose: Specifies whether a lock is an exclusive lock, or a shared Description: The href element contains the root of the lock. The
server SHOULD include this in all DAV:lockdiscovery property
values and the response to LOCK requests.
<!ELEMENT lockroot (href) >
14.13. lockscope XML Element
Name: lockscope
Purpose: Specifies whether a lock is an exclusive lock, or a shared
lock. lock.
<!ELEMENT lockscope (exclusive | shared) > <!ELEMENT lockscope (exclusive | shared) >
12.7.1. exclusive XML Element 14.14. locktoken XML Element
Name: exclusive Name: locktoken
Namespace: DAV: Purpose: The lock token associated with a lock.
Purpose: Specifies an exclusive lock Description: The href contains a single lock token URI which refers
to the lock.
<!ELEMENT exclusive EMPTY > <!ELEMENT locktoken (href) >
12.7.2. shared XML Element 14.15. locktype XML Element
Name: shared Name: locktype
Namespace: DAV: Purpose: Specifies the access type of a lock. At present, this
specification only defines one lock type, the write lock.
Purpose: Specifies a shared lock <!ELEMENT locktype (write) >
<!ELEMENT shared EMPTY > 14.16. multistatus XML Element
12.8. locktype XML Element Name: multistatus
Name: locktype Purpose: Contains multiple response messages.
Namespace: DAV: Description: The 'responsedescription' element at the top level is
used to provide a general message describing the overarching
nature of the response. If this value is available an application
may use it instead of presenting the individual response
descriptions contained within the responses.
Purpose: Specifies the access type of a lock. At present, this <!ELEMENT multistatus (response*, responsedescription?) >
specification only defines one lock type, the write lock.
<!ELEMENT locktype (write) > 14.17. owner XML Element
12.8.1. write XML Element Name: owner
Name: write Purpose: Provides information about the creator of a lock.
Namespace: DAV: Description: Allows a client to provide information sufficient for
either directly contacting a principal (such as a telephone number
or Email URI), or for discovering the principal (such as the URL
of a homepage) who created a lock. The value provided MUST be
treated as a dead property in terms of XML Information Item
preservation. The server MUST NOT alter the value unless the
owner value provided by the client is empty. For a certain amount
of interoperability between different client implementations, if
clients have URI-formatted contact information for the lock
creator suitable for user display, then clients SHOULD put those
URIs in 'href' child elements of the 'owner' element.
Purpose: Specifies a write lock. Extensibility: MAY be extended with child elements, mixed content,
text content or attributes.
<!ELEMENT write EMPTY > <!ELEMENT owner ANY >
12.9. multistatus XML Element 14.18. prop XML Element
Name: multistatus Name: prop
Namespace: DAV: Purpose: Contains properties related to a resource.
Purpose: Contains multiple response messages. Description: A generic container for properties defined on
resources. All elements inside a 'prop' XML element MUST define
properties related to the resource, although possible property
names are in no way limited to those property names defined in
this document or other standards. This element MUST NOT contain
text or mixed content.
Description: The responsedescription at the top level is used to <!ELEMENT prop ANY >
provide a general message describing the overarching nature of the
response. If this value is available an application may use it
instead of presenting the individual response descriptions
contained within the responses.
<!ELEMENT multistatus (response+, responsedescription?) > 14.19. propertyupdate XML Element
12.9.1. response XML Element Name: propertyupdate
Name: response Purpose: Contains a request to alter the properties on a resource.
Namespace: DAV: Description: This XML element is a container for the information
required to modify the properties on the resource.
Purpose: Holds a single response describing the effect of a method <!ELEMENT propertyupdate (remove | set)+ >
on resource and/or its properties.
Description: A particular href MUST NOT appear more than once as the 14.20. propfind XML Element
child of a response XML element under a multistatus XML element.
This requirement is necessary in order to keep processing costs
for a response to linear time. Essentially, this prevents having
to search in order to group together all the responses by href.
There are, however, no requirements regarding ordering based on
href values.
<!ELEMENT response (href, ((href*, status)|(propstat+)), Name: propfind
responsedescription?) >
12.9.1.1. propstat XML Element Purpose: Specifies the properties to be returned from a PROPFIND
method. Four special elements are specified for use with
'propfind': 'prop', 'allprop', 'include' and 'propname'. If
'prop' is used inside 'propfind' it MUST NOT contain property
values.
Name: propstat <!ELEMENT propfind ( propname | (allprop, include?) | prop ) >
Namespace: DAV: 14.21. propname XML Element
Purpose: Groups together a prop and status element that is Name: propname
associated with a particular href element.
Description: The propstat XML element MUST contain one prop XML Purpose: Specifies that only a list of property names on the
resource is to be returned.
<!ELEMENT propname EMPTY >
14.22. propstat XML Element
Name: propstat
Purpose: Groups together a prop and status element that is
associated with a particular 'href' element.
Description: The propstat XML element MUST contain one prop XML
element and one status XML element. The contents of the prop XML element and one status XML element. The contents of the prop XML
element MUST only list the names of properties to which the result element MUST only list the names of properties to which the result
in the status element applies. in the status element applies. The optional precondition/
postcondition element and 'responsedescription' text also apply to
<!ELEMENT propstat (prop, status, responsedescription?) > the properties named in 'prop'.
12.9.1.2. status XML Element <!ELEMENT propstat (prop, status, error?, responsedescription?) >
Name: status 14.23. remove XML Element
Namespace: DAV: Name: remove
Purpose: Holds a single HTTP status-line Purpose: Lists the properties to be removed from a resource.
Value: status-line ;status-line defined in [RFC2068] Description: Remove instructs that the properties specified in prop
should be removed. Specifying the removal of a property that does
not exist is not an error. All the XML elements in a 'prop' XML
element inside of a 'remove' XML element MUST be empty, as only
the names of properties to be removed are required.
<!ELEMENT status (#PCDATA) > <!ELEMENT remove (prop) >
12.9.2. responsedescription XML Element 14.24. response XML Element
Name: responsedescription Name: response
Namespace: DAV: Purpose: Holds a single response describing the effect of a method
on resource and/or its properties.
Purpose: Contains a message that can be displayed to the user Description: The 'href' element contains a HTTP URL pointing to a
explaining the nature of the response. WebDAV resource when used in the 'response' container. A
particular 'href' value MUST NOT appear more than once as the
child of a 'response' XML element under a 'multistatus' XML
element. This requirement is necessary in order to keep
processing costs for a response to linear time. Essentially, this
prevents having to search in order to group together all the
responses by 'href'. There are, however, no requirements
regarding ordering based on 'href' values. The optional
precondition/postcondition element and 'responsedescription' text
can provide additional information about this resource relative to
the request or result.
Description: This XML element provides information suitable to be <!ELEMENT response (href, ((href*, status)|(propstat+)),
presented to a user. error?, responsedescription? , location?) >
<!ELEMENT responsedescription (#PCDATA) > 14.25. responsedescription XML Element
12.10. owner XML Element Name: responsedescription
Name: owner Purpose: Contains information about a status response within a
Multi-Status.
Namespace: DAV: Description: Provides information suitable to be presented to a
user.
Purpose: Provides information about the principal taking out a lock. <!ELEMENT responsedescription (#PCDATA) >
Description: The owner XML element provides information sufficient 14.26. set XML Element
for either directly contacting a principal (such as a telephone
number or Email URI), or for discovering the principal (such as
the URL of a homepage) who owns a lock.
<!ELEMENT owner ANY> Name: set
12.11. prop XML element Purpose: Lists the property values to be set for a resource.
Name: prop Description: The 'set' element MUST contain only a 'prop' element.
The elements contained by the 'prop' element inside the 'set'
element MUST specify the name and value of properties that are set
on the resource identified by Request-URI. If a property already
exists then its value is replaced. Language tagging information
appearing in the scope of the 'prop' element (in the "xml:lang"
attribute, if present) MUST be persistently stored along with the
property, and MUST be subsequently retrievable using PROPFIND.
Namespace: DAV: <!ELEMENT set (prop) >
Purpose: Contains properties related to a resource. 14.27. shared XML Element
Description: The prop XML element is a generic container for Name: shared
properties defined on resources. All elements inside a prop XML
element MUST define properties related to the resource. No other
elements may be used inside of a prop element.
<!ELEMENT prop ANY> Purpose: Specifies a shared lock.
12.12. propertybehavior XML element <!ELEMENT shared EMPTY >
Name: propertybehavior 14.28. status XML Element
Namespace: DAV: Name: status
Purpose: Holds a single HTTP status-line.
Purpose: Specifies how properties are handled during a COPY or MOVE. Value: status-line (defined in Section 6.1 of [RFC2616])
Description: The propertybehavior XML element specifies how <!ELEMENT status (#PCDATA) >
properties are handled during a COPY or MOVE. If this XML element
is not included in the request body then the server is expected to
act as defined by the default property handling behavior of the
associated method. All WebDAV compliant resources MUST support
the propertybehavior XML element.
<!ELEMENT propertybehavior (omit | keepalive) > 14.29. timeout XML Element
12.12.1. keepalive XML element Name: timeout
Name: keepalive Purpose: The number of seconds remaining before a lock expires.
Namespace: DAV: Value: TimeType (defined in Section 10.7).
Purpose: Specifies requirements for the copying/moving of live <!ELEMENT timeout (#PCDATA) >
properties.
Description: If a list of URIs is included as the value of keepalive 14.30. write XML Element
then the named properties MUST be "live" after they are copied
(moved) to the destination resource of a COPY (or MOVE). If the
value "*" is given for the keepalive XML element, this designates
that all live properties on the source resource MUST be live on
the destination. If the requirements specified by the keepalive
element can not be honored then the method MUST fail with a 412
(Precondition Failed). All DAV compliant resources MUST support
the keepalive XML element for use with the COPY and MOVE methods.
Value: "*" ; #PCDATA value can only be "*" Name: write
<!ELEMENT keepalive (#PCDATA | href+) > Purpose: Specifies a write lock.
12.12.2. omit XML element <!ELEMENT write EMPTY >
Name: omit 15. DAV Properties
Namespace: DAV: For DAV properties, the name of the property is also the same as the
name of the XML element that contains its value. In the section
below, the final line of each section gives the element type
declaration using the format defined in [REC-XML]. The "Value"
field, where present, specifies further restrictions on the allowable
contents of the XML element using BNF (i.e., to further restrict the
values of a PCDATA element).
Purpose: The omit XML element instructs the server that it should A protected property is one which cannot be changed with a PROPPATCH
use best effort to copy properties but a failure to copy a request. There may be other requests which would result in a change
property MUST NOT cause the method to fail. to a protected property (as when a LOCK request affects the value of
DAV:lockdiscovery). Note that a given property could be protected on
one type of resource, but not protected on another type of resource.
Description: The default behavior for a COPY or MOVE is to copy/move A computed property is one with a value defined in terms of a
all properties or fail the method. In certain circumstances, such computation (based on the content and other properties of that
as when a server copies a resource over another protocol such as resource, or even of some other resource). A computed property is
FTP, it may not be possible to copy/move the properties associated always a protected property.
with the resource. Thus any attempt to copy/move over FTP would
always have to fail because properties could not be moved over,
even as dead properties. All DAV compliant resources MUST support
the omit XML element on COPY/MOVE methods.
<!ELEMENT omit EMPTY > COPY and MOVE behavior refers to local COPY and MOVE operations.
12.13. propertyupdate XML element For properties defined based on HTTP GET response headers (DAV:get*),
the header value could include LWS as defined in [RFC2616], Section
4.2. Server implementors SHOULD strip LWS from these values before
using as WebDAV property values.
Name: propertyupdate 15.1. creationdate Property
Namespace: DAV: Name: creationdate
Purpose: Contains a request to alter the properties on a resource. Purpose: Records the time and date the resource was created.
Description: This XML element is a container for the information Value: date-time (defined in [RFC3339], see the ABNF in section
required to modify the properties on the resource. This XML 5.6.)
element is multi-valued.
<!ELEMENT propertyupdate (remove | set)+ > Protected: MAY be protected. Some servers allow DAV:creationdate
to be changed to reflect the time the document was created if that
is more meaningful to the user (rather than the time it was
uploaded). Thus, clients SHOULD NOT use this property in
synchronization logic (use DAV:getetag instead).
12.13.1. remove XML element COPY/MOVE behaviour: This property value SHOULD be kept during a
MOVE operation, but is normally re-initialized when a resource is
created with a COPY. It should not be set in a COPY.
Name: remove Description: The DAV:creationdate property SHOULD be defined on all
DAV compliant resources. If present, it contains a timestamp of
the moment when the resource was created. Servers that are
incapable of persistently recording the creation date SHOULD
instead leave it undefined (i.e. report "Not Found").
Namespace: DAV: <!ELEMENT creationdate (#PCDATA) >
Purpose: Lists the DAV properties to be removed from a resource. 15.2. displayname Property
Description: Remove instructs that the properties specified in prop Name: displayname
should be removed. Specifying the removal of a property that does
not exist is not an error. All the XML elements in a prop XML
element inside of a remove XML element MUST be empty, as only the
names of properties to be removed are required.
<!ELEMENT remove (prop) > Purpose: Provides a name for the resource that is suitable for
presentation to a user.
12.13.2. set XML element Value: Any text.
Name: set Protected: SHOULD NOT be protected. Note that servers implementing
[RFC2518] might have made this a protected property as this is a
new requirement.
Namespace: DAV: COPY/MOVE behaviour: This property value SHOULD be preserved in
COPY and MOVE operations.
Purpose: Lists the DAV property values to be set for a resource. Description: Contains a description of the resource that is
suitable for presentation to a user. This property is defined on
the resource, and hence SHOULD have the same value independent of
the Request-URI used to retrieve it (thus computing this property
based on the Request-URI is deprecated). While generic clients
might display the property value to end users, client UI designers
must understand that the method for identifying resources is still
the URL. Changes to DAV:displayname do not issue moves or copies
to the server, but simply change a piece of meta-data on the
individual resource. Two resources can have the same DAV:
displayname value even within the same collection.
Description: The set XML element MUST contain only a prop XML <!ELEMENT displayname (#PCDATA) >
element. The elements contained by the prop XML element inside
the set XML element MUST specify the name and value of properties
that are set on the resource identified by Request-URI. If a
property already exists then its value is replaced. Language
tagging information in the property's value (in the "xml:lang"
attribute, if present) MUST be persistently stored along with the
property, and MUST be subsequently retrievable using PROPFIND.
<!ELEMENT set (prop) > 15.3. getcontentlanguage Property
12.14. propfind XML Element Name: getcontentlanguage
Name: propfind Purpose: Contains the Content-Language header value (from Section
14.12 of [RFC2616]) as it would be returned by a GET without
accept headers.
Namespace: DAV: Value: language-tag (language-tag is defined in Section 3.10 of
[RFC2616]).
Purpose: Specifies the properties to be returned from a PROPFIND Protected: SHOULD NOT be protected, so that clients can reset the
method. Two special elements are specified for use with propfind, language. Note that servers implementing [RFC2518] might have
allprop and propname. If prop is used inside propfind it MUST made this a protected property as this is a new requirement.
only contain property names, not values.
<!ELEMENT propfind (allprop | propname | prop) > COPY/MOVE behaviour: This property value SHOULD be preserved in
COPY and MOVE operations.
12.14.1. allprop XML Element Description: The DAV:getcontentlanguage property MUST be defined on
any DAV compliant resource that returns the Content-Language
header on a GET.
Name: allprop <!ELEMENT getcontentlanguage (#PCDATA) >
Namespace: DAV: 15.4. getcontentlength Property
Purpose: The allprop XML element specifies that all property names Name: getcontentlength
and values on the resource are to be returned.
<!ELEMENT allprop EMPTY > Purpose: Contains the Content-Length header returned by a GET
without accept headers.
12.14.2. propname XML Element Value: See Section 14.13 of [RFC2616].
Name: propname Protected: This property is computed, therefore protected.
Namespace: DAV: Description: The DAV:getcontentlength property MUST be defined on
any DAV compliant resource that returns the Content-Length header
in response to a GET.
Purpose: The propname XML element specifies that only a list of COPY/MOVE behaviour: This property value is dependent on the size
property names on the resource is to be returned. of the destination resource, not the value of the property on the
source resource.
<!ELEMENT propname EMPTY > <!ELEMENT getcontentlength (#PCDATA) >
13. DAV Properties 15.5. getcontenttype Property
For DAV properties, the name of the property is also the same as the Name: getcontenttype
name of the XML element that contains its value. In the section
below, the final line of each section gives the element type
declaration using the format defined in [REC-XML]. The "Value"
field, where present, specifies further restrictions on the allowable
contents of the XML element using BNF (i.e., to further restrict the
values of a PCDATA element).
13.1. creationdate Property Purpose: Contains the Content-Type header value (from Section 14.17
of [RFC2616]) as it would be returned by a GET without accept
headers.
Name: creationdate Value: media-type (defined in Section 3.7 of [RFC2616])
Namespace: DAV: Protected: Potentially protected if the server prefers to assign
content types on its own (see also discussion in Section 9.7.1).
Purpose: Records the time and date the resource was created. COPY/MOVE behaviour: This property value SHOULD be preserved in
COPY and MOVE operations.
Value: date-time ; See Appendix A.2 Description: This property MUST be defined on any DAV compliant
resource that returns the Content-Type header in response to a
GET.
Description: The creationdate property should be defined on all DAV <!ELEMENT getcontenttype (#PCDATA) >
compliant resources. If present, it contains a timestamp of the
moment when the resource was created (i.e., the moment it had non-
null state).
<!ELEMENT creationdate (#PCDATA) > 15.6. getetag Property
13.2. displayname Property Name: getetag
Name: displayname Purpose: Contains the ETag header value (from Section 14.19 of
[RFC2616]) as it would be returned by a GET without accept
headers.
Namespace: DAV: Value: entity-tag (defined in Section 3.11 of [RFC2616])
Purpose: Provides a name for the resource that is suitable for Protected: MUST be protected because this value is created and
presentation to a user. controlled by the server.
Description: The displayname property should be defined on all DAV COPY/MOVE behaviour: This property value is dependent on the final
compliant resources. If present, the property contains a state of the destination resource, not the value of the property
description of the resource that is suitable for presentation to a on the source resource. Also note the considerations in
user. Section 8.8.
<!ELEMENT displayname (#PCDATA) > Description: The getetag property MUST be defined on any DAV
compliant resource that returns the Etag header. Refer to Section
3.11 of RFC2616 for a complete definition of the semantics of an
ETag, and to Section 8.6 for a discussion of ETags in WebDAV.
13.3. getcontentlanguage Property <!ELEMENT getetag (#PCDATA) >
Name: getcontentlanguage 15.7. getlastmodified Property
Namespace: DAV: Name: getlastmodified
Purpose: Contains the Content-Language header returned by a GET Purpose: Contains the Last-Modified header value (from Section
without accept headers 14.29 of [RFC2616]) as it would be returned by a GET method
without accept headers.
Description: The getcontentlanguage property MUST be defined on any Value: rfc1123-date (defined in Section 3.3.1 of [RFC2616])
DAV compliant resource that returns the Content-Language header on
a GET.
Value: language-tag ;language-tag is defined in section 14.13 of Protected: SHOULD be protected because some clients may rely on the
[RFC2068] value for appropriate caching behavior, or on the value of the
Last-Modified header to which this property is linked.
<!ELEMENT getcontentlanguage (#PCDATA) > COPY/MOVE behaviour: This property value is dependent on the last
modified date of the destination resource, not the value of the
property on the source resource. Note that some server
implementations use the file system date modified value for the
DAV:getlastmodified value, and this can be preserved in a MOVE
even when the HTTP Last-Modified value SHOULD change. Note that
since [RFC2616] requires clients to use ETags where provided, a
server implementing ETags can count on clients using a much better
mechanism than modification dates for offline synchronization or
cache control. Also note the considerations in Section 8.8.
13.4. getcontentlength Property Description: Note that the last-modified date on a resource SHOULD
only reflect changes in the body (the GET responses) of the
resource. A change in a property only SHOULD NOT cause the last-
modified date to change, because clients MAY rely on the last-
modified date to know when to overwrite the existing body. The
DAV:getlastmodified property MUST be defined on any DAV compliant
resource that returns the Last-Modified header in response to a
GET.
Name: getcontentlength <!ELEMENT getlastmodified (#PCDATA) >
Namespace: DAV: 15.8. lockdiscovery Property
Purpose: Contains the Content-Length header returned by a GET Name: lockdiscovery
without accept headers.
Description: The getcontentlength property MUST be defined on any Purpose: Describes the active locks on a resource
DAV compliant resource that returns the Content-Length header in
response to a GET.
Value: content-length ; see section 14.14 of [RFC2068] Protected: MUST be protected. Clients change the list of locks
through LOCK and UNLOCK, not through PROPPATCH.
<!ELEMENT getcontentlength (#PCDATA) > COPY/MOVE behaviour: The value of this property depends on the lock
state of the destination, not on the locks of the source resource.
Recall that locks are not moved in a MOVE operation.
13.5. getcontenttype Property Description: Returns a listing of who has a lock, what type of lock
he has, the timeout type and the time remaining on the timeout,
and the associated lock token. Owner information MAY be omitted
if it is considered sensitive. If there are no locks, but the
server supports locks, the property will be present but contain
zero 'activelock' elements. If there is one or more lock, an
'activelock' element appears for each lock on the resource. This
property is NOT lockable with respect to write locks (Section 7).
Name: getcontenttype <!ELEMENT lockdiscovery (activelock)* >
Namespace: DAV: 15.8.1. Example - Retrieving DAV:lockdiscovery
Purpose: Contains the Content-Type header returned by a GET without >>Request
accept headers.
Description: This getcontenttype property MUST be defined on any DAV PROPFIND /container/ HTTP/1.1
compliant resource that returns the Content-Type header in Host: www.example.com
response to a GET. Content-Length: xxxx
Content-Type: application/xml; charset="utf-8"
Value: media-type ; defined in section 3.7 of [RFC2068] <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D='DAV:'>
<D:prop><D:lockdiscovery/></D:prop>
</D:propfind>
<!ELEMENT getcontenttype (#PCDATA) > >>Response
13.6. getetag Property HTTP/1.1 207 Multi-Status
Name: getetag Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
Namespace: DAV: <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D='DAV:'>
<D:response>
<D:href>http://www.example.com/container/</D:href>
<D:propstat>
<D:prop>
<D:lockdiscovery>
<D:activelock>
<D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope>
<D:depth>0</D:depth>
<D:owner>Jane Smith</D:owner>
<D:timeout>Infinite</D:timeout>
<D:locktoken>
<D:href
>urn:uuid:f81de2ad-7f3d-a1b2-4f3c-00a0c91a9d76</D:href>
</D:locktoken>
<D:lockroot>
<D:href>http://www.example.com/container/</D:href>
</D:lockroot>
</D:activelock>
</D:lockdiscovery>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
Purpose: Contains the ETag header returned by a GET without accept This resource has a single exclusive write lock on it, with an
headers. infinite timeout.
Description: The getetag property MUST be defined on any DAV 15.9. resourcetype Property
compliant resource that returns the Etag header.
Value: entity-tag ; defined in section 3.11 of [RFC2068] Name: resourcetype
<!ELEMENT getetag (#PCDATA) > Purpose: Specifies the nature of the resource.
13.7. getlastmodified Property Protected: SHOULD be protected. Resource type is generally decided
through the operation creating the resource (MKCOL vs PUT), not by
PROPPATCH.
Name: getlastmodified COPY/MOVE behaviour: Generally a COPY/MOVE of a resource results in
the same type of resource at the destination.
Namespace: DAV: Description: MUST be defined on all DAV compliant resources. Each
child element identifies a specific type the resource belongs to,
such as 'collection', which is the only resource type defined by
this specification (see Section 14.3). If the element contains
the 'collection' child element plus additional unrecognized
elements, it should generally be treated as a collection. If the
element contains no recognized child elements, it should be
treated as a non-collection resource. The default value is empty.
This element MUST NOT contain text or mixed content. Any custom
child element is considered to be an identifier for a resource
type.
Purpose: Contains the Last-Modified header returned by a GET method Example: (fictional example to show extensibility)
without accept headers.
Description: Note that the last-modified date on a resource may <x:resourcetype xmlns:x="DAV:">
reflect changes in any part of the state of the resource, not <x:collection/>
necessarily just a change to the response to the GET method. For <f:search-results xmlns:f="http://www.example.com/ns"/>
example, a change in a property may cause the last-modified date </x:resourcetype>
to change. The getlastmodified property MUST be defined on any
DAV compliant resource that returns the Last-Modified header in
response to a GET.
Value: HTTP-date ; defined in section 3.3.1 of [RFC2068] 15.10. supportedlock Property
<!ELEMENT getlastmodified (#PCDATA) > Name: supportedlock
13.8. lockdiscovery Property Purpose: To provide a listing of the lock capabilities supported by
the resource.
Name: lockdiscovery Protected: MUST be protected. Servers determine what lock
mechanisms are supported, not clients.
Namespace: DAV: COPY/MOVE behaviour: This property value is dependent on the kind
of locks supported at the destination, not on the value of the
property at the source resource. Servers attempting to COPY to a
destination should not attempt to set this property at the
destination.
Purpose: Describes the active locks on a resource Description: Returns a listing of the combinations of scope and
Description: The lockdiscovery property returns a listing of who has access types which may be specified in a lock request on the
a lock, what type of lock he has, the timeout type and the time resource. Note that the actual contents are themselves controlled
remaining on the timeout, and the associated lock token. The by access controls so a server is not required to provide
server is free to withhold any or all of this information if the information the client is not authorized to see. This property is
requesting principal does not have sufficient access rights to see NOT lockable with respect to write locks (Section 7).
the requested data.
<!ELEMENT lockdiscovery (activelock)* > <!ELEMENT supportedlock (lockentry)* >
13.8.1. Example - Retrieving the lockdiscovery Property 15.10.1. Example - Retrieving DAV:supportedlock
>>Request >>Request
PROPFIND /container/ HTTP/1.1 PROPFIND /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Content-Length: xxxx Content-Length: xxxx
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D='DAV:'> <D:propfind xmlns:D="DAV:">
<D:prop><D:lockdiscovery/></D:prop> <D:prop><D:supportedlock/></D:prop>
</D:propfind> </D:propfind>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D='DAV:'> <D:multistatus xmlns:D="DAV:">
<D:response> <D:response>
<D:href>http://www.foo.bar/container/</D:href> <D:href>http://www.example.com/container/</D:href>
<D:propstat> <D:propstat>
<D:prop> <D:prop>
<D:lockdiscovery> <D:supportedlock>
<D:activelock> <D:lockentry>
<D:locktype><D:write/></D:locktype> <D:lockscope><D:exclusive/></D:lockscope>
<D:lockscope><D:exclusive/></D:lockscope> <D:locktype><D:write/></D:locktype>
<D:depth>0</D:depth> </D:lockentry>
<D:owner>Jane Smith</D:owner> <D:lockentry>
<D:timeout>Infinite</D:timeout> <D:lockscope><D:shared/></D:lockscope>
<D:locktoken> <D:locktype><D:write/></D:locktype>
<D:href> </D:lockentry>
opaquelocktoken:f81de2ad-7f3d-a1b2-4f3c-00a0c91a9d76 </D:supportedlock>
</D:href> </D:prop>
</D:locktoken> <D:status>HTTP/1.1 200 OK</D:status>
</D:activelock> </D:propstat>
</D:lockdiscovery> </D:response>
</D:prop> </D:multistatus>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
This resource has a single exclusive write lock on it, with an 16. Precondition/Postcondition XML Elements
infinite timeout.
13.9. resourcetype Property As introduced in Section 8.7, extra information on error conditions
can be included in the body of many status responses. This section
makes requirements on the use of the error body mechanism and
introduces a number of precondition and postcondition codes.
Name: resourcetype A "precondition" of a method describes the state of the server that
must be true for that method to be performed. A "postcondition" of a
method describes the state of the server that must be true after that
method has been completed.
Namespace: DAV: Each precondition and postcondition has a unique XML element
associated with it. In a 207 Multi-Status response, the XML element
MUST appear inside an 'error' element in the appropriate 'propstat or
'response' element depending on whether the condition applies to one
or more properties or to the resource as a whole. In all other error
responses where this specification's 'error' body is used, the
precondition/postcondition XML element MUST be returned as the child
of a top-level 'error' element in the response body, unless otherwise
negotiated by the request, along with an appropriate response status.
The most common response status codes are 403 (Forbidden) if the
request should not be repeated because it will always fail, and 409
(Conflict) if it is expected that the user might be able to resolve
the conflict and resubmit the request. The 'error' element MAY
contain child elements with specific error information and MAY be
extended with any custom child elements.
Purpose: Specifies the nature of the resource. This mechanism does not take the place of using a correct numeric
status code as defined here or in HTTP, because the client MUST
always be able to take a reasonable course of action based only on
the numeric code. However, it does remove the need to define new
numeric codes. The new machine-readable codes used for this purpose
are XML elements classified as preconditions and postconditions, so
naturally any group defining a new condition code can use their own
namespace. As always, the "DAV:" namespace is reserved for use by
IETF-chartered WebDAV working groups.
Description: The resourcetype property MUST be defined on all DAV A server supporting this specification SHOULD use the XML error
compliant resources. The default value is empty. whenever a precondition or postcondition defined in this document is
violated. For error conditions not specified in this document, the
server MAY simply choose an appropriate numeric status and leave the
response body blank. However, a server MAY instead use a custom
condition code and other supporting text, because even when clients
do not automatically recognize condition codes they can be quite
useful in interoperability testing and debugging.
<!ELEMENT resourcetype ANY > Example - Response with precondition code
>>Response
13.10. source Property HTTP/1.1 423 Locked
Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
Name: source <?xml version="1.0" encoding="utf-8" ?>
<D:error xmlns:D="DAV:">
<D:lock-token-submitted>
<D:href>/workspace/webdav/</D:href>
</D:lock-token-submitted>
</D:error>
Namespace: DAV: In this example, a client unaware of a depth-infinity lock on the
parent collection "/workspace/webdav/" attempted to modify the
collection member "/workspace/webdav/proposal.doc".
Purpose: The destination of the source link identifies the resource Some other useful preconditions and postconditions have been defined
that contains the unprocessed source of the link's source. in other specifications extending WebDAV, such as [RFC3744] (see
particularly Section 7.1.1), [RFC3253], and [RFC3648].
Description: The source of the link (src) is typically the URI of All these elements are in the "DAV:" namespace. If not specified
the output resource on which the link is defined, and there is otherwise, the content for each condition's XML element is defined to
typically only one destination (dst) of the link, which is the URI be empty.
where the unprocessed source of the resource may be accessed.
When more than one link destination exists, this specification
asserts no policy on ordering.
<!ELEMENT source (link)* > Name: lock-token-matches-request-uri
13.10.1. Example - A source Property Use with: 409 Conflict
<?xml version="1.0" encoding="utf-8" ?> Purpose: (precondition) -- A request may include a Lock-Token header
<D:prop xmlns:D="DAV:" xmlns:F="http://www.foocorp.com/Project/"> to identify a lock for the UNLOCK method. However, if the
<D:source> Request-URI does not fall within the scope of the lock identified
<D:link> by the token, the server SHOULD use this error. The lock may have
<F:projfiles>Source</F:projfiles> a scope that does not include the Request-URI, or the lock could
<D:src>http://foo.bar/program</D:src> have disappeared, or the token may be invalid.
<D:dst>http://foo.bar/src/main.c</D:dst>
</D:link>
<D:link>
<F:projfiles>Library</F:projfiles>
<D:src>http://foo.bar/program</D:src>
<D:dst>http://foo.bar/src/main.lib</D:dst>
</D:link>
<D:link>
<F:projfiles>Makefile</F:projfiles>
<D:src>http://foo.bar/program</D:src>
<D:dst>http://foo.bar/src/makefile</D:dst>
</D:link>
</D:source>
</D:prop>
In this example the resource http://foo.bar/program has a source Name: lock-token-submitted (precondition)
property that contains three links. Each link contains three
elements, two of which, src and dst, are part of the DAV schema
defined in this document, and one which is defined by the schema
http://www.foocorp.com/project/ (Source, Library, and Makefile). A
client which only implements the elements in the DAV spec will not
understand the foocorp elements and will ignore them, thus seeing the
expected source and destination links. An enhanced client may know
about the foocorp elements and be able to present the user with
additional information about the links. This example demonstrates
the power of XML markup, allowing element values to be enhanced
without breaking older clients.
13.11. supportedlock Property Use with: 423 Locked
Name: supportedlock Purpose: The request could not succeed because a lock token should
have been submitted. This element, if present, MUST contain at
least one URL of a locked resource that prevented the request. In
cases of MOVE, COPY and DELETE where collection locks are
involved, it can be difficult for the client to find out which
locked resource made the request fail -- but the server is only
resonsible for returning one such locked resource. The server MAY
return every locked resource that prevented the request from
succeeding if it knows them all.
Namespace: DAV: <!ELEMENT lock-token-submitted (href+) >
Purpose: To provide a listing of the lock capabilities supported by Name: no-conflicting-lock (precondition)
the resource.
Description: The supportedlock property of a resource returns a Use with: Typically 423 Locked
listing of the combinations of scope and access types which may be
specified in a lock request on the resource. Note that the actual
contents are themselves controlled by access controls so a server
is not required to provide information the client is not
authorized to see.
<!ELEMENT supportedlock (lockentry)* > Purpose: A LOCK request failed due the presence of an already
existing conflicting lock. Note that a lock can be in conflict
although the resource to which the request was directed is only
indirectly locked. In this case, the precondition code can be
used to inform the client about the resource which is the root of
the conflicting lock, avoiding a separate lookup of the
"lockdiscovery" property.
13.11.1. Example - Retrieving the supportedlock Property <!ELEMENT no-conflicting-lock (href)* >
>>Request Name: no-external-entities
PROPFIND /container/ HTTP/1.1 Use with: 403 Forbidden
Host: www.foo.bar
Content-Length: xxxx
Content-Type: text/xml; charset="utf-8"
<?xml version="1.0" encoding="utf-8" ?> Purpose: (precondition) -- If the server rejects a client request
<D:propfind xmlns:D="DAV:"> because the request body contains an external entity, the server
<D:prop><D:supportedlock/></D:prop> SHOULD use this error.
</D:propfind>
>>Response Name: preserved-live-properties
HTTP/1.1 207 Multi-Status Use with: 409 Conflict
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> Purpose: (postcondition) -- The server received an otherwise-valid
<D:multistatus xmlns:D="DAV:"> MOVE or COPY request, but cannot maintain the live properties with
<D:response> the same behavior at the destination. It may be that the server
<D:href>http://www.foo.bar/container/</D:href> only supports some live properties in some parts of the
<D:propstat> repository, or simply has an internal error.
<D:prop>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
14. Instructions for Processing XML in DAV Name: propfind-finite-depth
All DAV compliant resources MUST ignore any unknown XML element and Use with: 403 Forbidden
all its children encountered while processing a DAV method that uses
XML as its command language. Purpose: (precondition) -- This server does not allow infinite-depth
PROPFIND requests on collections.
Name: cannot-modify-protected-property
Use with: 403 Forbidden
Purpose: (precondition) -- The client attempted to set a protected
property in a PROPPATCH (such as DAV:getetag). See also
[RFC3253], Section 3.12.
17. XML Extensibility in DAV
The XML namespace extension ([REC-XML-NAMES]) is used in this
specification in order to allow for new XML elements to be added
without fear of colliding with other element names. Although WebDAV
request and response bodies can be extended by arbitrary XML
elements, which can be ignored by the message recipient, an XML
element in the "DAV:" namespace SHOULD NOT be used in the request or
response body unless that XML element is explicitly defined in an
IETF RFC reviewed by a WebDAV working group.
For WebDAV to be both extensibile and backwards-compatible, both
clients and servers need to know how to behave when unexpected or
unrecognized command extensions are received. For XML processing,
this means that clients and servers MUST process received XML
documents as if unexpected elements and attributes (and all children
of unrecognized elements) were not there. An unexpected element or
attribute includes one which may be used in another context but is
not expected here. Ignoring such items for purposes of processing
can of course be consistent with logging all information or
presenting for debugging.
This restriction also applies to the processing, by clients, of DAV This restriction also applies to the processing, by clients, of DAV
property values where unknown XML elements SHOULD be ignored unless property values where unexpected XML elements SHOULD be ignored
the property's schema declares otherwise. unless the property's schema declares otherwise.
This restriction does not apply to setting dead DAV properties on the This restriction does not apply to setting dead DAV properties on the
server where the server MUST record unknown XML elements. server where the server MUST record all XML elements.
Additionally, this restriction does not apply to the use of XML where Additionally, this restriction does not apply to the use of XML where
XML happens to be the content type of the entity body, for example, XML happens to be the content type of the entity body, for example,
when used as the body of a PUT. when used as the body of a PUT.
Since XML can be transported as text/xml or application/xml, a DAV Processing instructions in XML SHOULD be ignored by recipients.
server MUST accept DAV method requests with XML parameters Thus, specifications extending WebDAV SHOULD NOT use processing
transported as either text/xml or application/xml, and DAV client instructions to define normative behavior.
MUST accept XML responses using either text/xml or application/xml.
15. DAV Compliance Classes XML DTD fragments are included for all the XML elements defined in
this specification. However, correct XML will not be valid according
to any DTD due to namespace usage and extension rules. In
particular:
A DAV compliant resource can choose from two classes of compliance. o Elements (from this specification) are in the "DAV:" namespace,
o Element ordering is irrelevant unless otherwise stated,
o Extension attributes MAY be added,
o For element type definitions of "ANY", the normative text
definition for that element defines what can be in it and what
that means.
o For element type definitions of "#PCDATA", extension elements MUST
NOT be added.
o For other element type definitions, including "EMPTY", extension
elements MAY be added.
Note that this means that elements containing elements cannot be
extended to contain text, and vice versa.
With DTD validation relaxed by the rules above, the constraints
described by the DTD fragments are normative (see for example
Appendix A). A recipient of a WebDAV message with an XML body MUST
NOT validate the XML document according to any hard-coded or
dynamically-declared DTD.
Note that this section describes backwards-compatible extensibility
rules. There might also be times when an extension is designed not
to be backwards-compatible, for example defining an extension that
reuses an XML element defined in this document but omitting one of
the child elements required by the DTDs in this specification.
18. DAV Compliance Classes
A DAV compliant resource can advertise several classes of compliance.
A client can discover the compliance classes of a resource by A client can discover the compliance classes of a resource by
executing OPTIONS on the resource, and examining the "DAV" header executing OPTIONS on the resource, and examining the "DAV" header
which is returned. which is returned. Note particularly that resources are spoken of as
being compliant, rather than servers. That is because theoretically
some resources on a server could support different feature sets.
E.g. a server could have a sub-repository where an advanced feature
like versioning was supported, even if that feature was not supported
on all sub-repositories.
Since this document describes extensions to the HTTP/1.1 protocol, Since this document describes extensions to the HTTP/1.1 protocol,
minimally all DAV compliant resources, clients, and proxies MUST be minimally all DAV compliant resources, clients, and proxies MUST be
compliant with [RFC2068]. compliant with [RFC2616].
Compliance classes are not necessarily sequential. A resource that A resource that is class 2 or class 3 compliant must also be class 1
is class 2 compliant must also be class 1 compliant; but if compliant.
additional compliance classes are defined later, a resource that is
class 1, 2, and 4 compliant might not be class 3 compliant. Also
note that identifiers other than numbers may be used as compliance
class identifiers.
15.1. Class 1 18.1. Class 1
A class 1 compliant resource MUST meet all "MUST" requirements in all A class 1 compliant resource MUST meet all "MUST" requirements in all
sections of this document. sections of this document.
Class 1 compliant resources MUST return, at minimum, the value "1" in Class 1 compliant resources MUST return, at minimum, the value "1" in
the DAV header on all responses to the OPTIONS method. the DAV header on all responses to the OPTIONS method.
15.2. Class 2 18.2. Class 2
A class 2 compliant resource MUST meet all class 1 requirements and A class 2 compliant resource MUST meet all class 1 requirements and
support the LOCK method, the supportedlock property, the support the LOCK method, the DAV:supportedlock property, the DAV:
lockdiscovery property, the Time-Out response header and the Lock- lockdiscovery property, the Time-Out response header and the Lock-
Token request header. A class "2" compliant resource SHOULD also Token request header. A class "2" compliant resource SHOULD also
support the Time-Out request header and the owner XML element. support the Time-Out request header and the 'owner' XML element.
Class 2 compliant resources MUST return, at minimum, the values "1" Class 2 compliant resources MUST return, at minimum, the values "1"
and "2" in the DAV header on all responses to the OPTIONS method. and "2" in the DAV header on all responses to the OPTIONS method.
16. Internationalization Considerations 18.3. Class 3
A resource can explicitly advertise its support for the revisions to
[RFC2518] made in this document. Class 1 MUST be supported as well.
Class 2 MAY be supported. Advertising class 3 support in addition to
class 1 and 2 means that the server supports all the requirements in
this specification. Advertising class 3 and class 1 support, but not
class 2, means that the server supports all the requirements in this
specification except possibly those that involve locking support.
Example:
DAV: 1, 3
19. Internationalization Considerations
In the realm of internationalization, this specification complies In the realm of internationalization, this specification complies
with the IETF Character Set Policy [RFC2277]. In this specification, with the IETF Character Set Policy [RFC2277]. In this specification,
human-readable fields can be found either in the value of a property, human-readable fields can be found either in the value of a property,
or in an error message returned in a response entity body. In both or in an error message returned in a response entity body. In both
cases, the human-readable content is encoded using XML, which has cases, the human-readable content is encoded using XML, which has
explicit provisions for character set tagging and encoding, and explicit provisions for character set tagging and encoding, and
requires that XML processors read XML elements encoded, at minimum, requires that XML processors read XML elements encoded, at minimum,
using the UTF-8 [UTF-8] encoding of the ISO 10646 multilingual plane. using the UTF-8 [RFC3629] and UTF-16 encodings of the ISO 10646
XML examples in this specification demonstrate use of the charset multilingual plane. XML examples in this specification demonstrate
parameter of the Content-Type header, as defined in [RFC2376], as use of the charset parameter of the Content-Type header, as defined
well as the XML "encoding" attribute, which together provide charset in [RFC3023], as well as the XML declarations which provide charset
identification information for MIME and XML processors. identification information for MIME and XML processors.
XML also provides a language tagging capability for specifying the XML also provides a language tagging capability for specifying the
language of the contents of a particular XML element. XML uses language of the contents of a particular XML element. The "xml:lang"
either IANA registered language tags (see [RFC1766]) or ISO 639 attribute appears on an XML element to identify the language of its
language tags [ISO-639] in the "xml:lang" attribute of an XML element content and attributes. See [REC-XML] for definitions of values and
to identify the language of its content and attributes. scoping.
WebDAV applications MUST support the character set tagging, character WebDAV applications MUST support the character set tagging, character
set encoding, and the language tagging functionality of the XML set encoding, and the language tagging functionality of the XML
specification. Implementors of WebDAV applications are strongly specification. Implementors of WebDAV applications are strongly
encouraged to read "XML Media Types" [RFC2376] for instruction on encouraged to read "XML Media Types" [RFC3023] for instruction on
which MIME media type to use for XML transport, and on use of the which MIME media type to use for XML transport, and on use of the
charset parameter of the Content-Type header. charset parameter of the Content-Type header.
Names used within this specification fall into three categories: Names used within this specification fall into four categories: names
names of protocol elements such as methods and headers, names of XML of protocol elements such as methods and headers, names of XML
elements, and names of properties. Naming of protocol elements elements, names of properties, and names of conditions. Naming of
follows the precedent of HTTP, using English names encoded in USASCII protocol elements follows the precedent of HTTP, using English names
for methods and headers. Since these protocol elements are not encoded in USASCII for methods and headers. Since these protocol
visible to users, and are in fact simply long token identifiers, they elements are not visible to users, and are simply long token
do not need to support encoding in multiple character sets. identifiers, they do not need to support multiple languages.
Similarly, though the names of XML elements used in this Similarly, the names of XML elements used in this specification are
specification are English names encoded in UTF-8, these names are not not visible to the user and hence do not need to support multiple
visible to the user, and hence do not need to support multiple languages.
character set encodings.
The name of a property defined on a resource is a URI. Although some WebDAV property names are qualified XML names (pairs of XML namespace
applications (e.g., a generic property viewer) will display property name and local name). Although some applications (e.g., a generic
URIs directly to their users, it is expected that the typical property viewer) will display property names directly to their users,
application will use a fixed set of properties, and will provide a it is expected that the typical application will use a fixed set of
mapping from the property name URI to a human-readable field when properties, and will provide a mapping from the property name and
displaying the property name to a user. It is only in the case where namespace to a human-readable field when displaying the property name
the set of properties is not known ahead of time that an application to a user. It is only in the case where the set of properties is not
need display a property name URI to a user. We recommend that known ahead of time that an application need display a property name
applications provide human-readable property names wherever feasible. to a user. We recommend that applications provide human-readable
property names wherever feasible.
For error reporting, we follow the convention of HTTP/1.1 status For error reporting, we follow the convention of HTTP/1.1 status
codes, including with each status code a short, English description codes, including with each status code a short, English description
of the code (e.g., 423 (Locked)). While the possibility exists that of the code (e.g., 423 (Locked)). While the possibility exists that
a poorly crafted user agent would display this message to a user, a poorly crafted user agent would display this message to a user,
internationalized applications will ignore this message, and display internationalized applications will ignore this message, and display
an appropriate message in the user's language and character set. an appropriate message in the user's language and character set.
Since interoperation of clients and servers does not require locale Since interoperation of clients and servers does not require locale
information, this specification does not specify any mechanism for information, this specification does not specify any mechanism for
transmission of this information. transmission of this information.
17. Security Considerations 20. Security Considerations
This section is provided to detail issues concerning security This section is provided to detail issues concerning security
implications of which WebDAV applications need to be aware. implications of which WebDAV applications need to be aware.
All of the security considerations of HTTP/1.1 (discussed in All of the security considerations of HTTP/1.1 (discussed in
[RFC2068]) and XML (discussed in [RFC2376]) also apply to WebDAV. In [RFC2616]) and XML (discussed in [RFC3023]) also apply to WebDAV. In
addition, the security risks inherent in remote authoring require addition, the security risks inherent in remote authoring require
stronger authentication technology, introduce several new privacy stronger authentication technology, introduce several new privacy
concerns, and may increase the hazards from poor server design. concerns, and may increase the hazards from poor server design.
These issues are detailed below. These issues are detailed below.
17.1. Authentication of Clients 20.1. Authentication of Clients
Due to their emphasis on authoring, WebDAV servers need to use Due to their emphasis on authoring, WebDAV servers need to use
authentication technology to protect not just access to a network authentication technology to protect not just access to a network
resource, but the integrity of the resource as well. Furthermore, resource, but the integrity of the resource as well. Furthermore,
the introduction of locking functionality requires support for the introduction of locking functionality requires support for
authentication. authentication.
A password sent in the clear over an insecure channel is an A password sent in the clear over an insecure channel is an
inadequate means for protecting the accessibility and integrity of a inadequate means for protecting the accessibility and integrity of a
resource as the password may be intercepted. Since Basic resource as the password may be intercepted. Since Basic
authentication for HTTP/1.1 performs essentially clear text authentication for HTTP/1.1 performs essentially clear text
transmission of a password, Basic authentication MUST NOT be used to transmission of a password, Basic authentication MUST NOT be used to
authenticate a WebDAV client to a server unless the connection is authenticate a WebDAV client to a server unless the connection is
secure. Furthermore, a WebDAV server MUST NOT send Basic secure. Furthermore, a WebDAV server MUST NOT send a Basic
authentication credentials in a WWW-Authenticate header unless the authentication challenge in a WWW-Authenticate header unless the
connection is secure. Examples of secure connections include a connection is secure. An example of a secure connection would be a
Transport Layer Security (TLS) connection employing a strong cipher Transport Layer Security (TLS) connection employing a strong cipher
suite with mutual authentication of client and server, or a suite and server authentication.
connection over a network which is physically secure, for example, an
isolated network in a building with restricted access.
WebDAV applications MUST support the Digest authentication scheme WebDAV applications MUST support the Digest authentication scheme
[RFC2069]. Since Digest authentication verifies that both parties to [RFC2617]. Since Digest authentication verifies that both parties to
a communication know a shared secret, a password, without having to a communication know a shared secret, a password, without having to
send that secret in the clear, Digest authentication avoids the send that secret in the clear, Digest authentication avoids the
security problems inherent in Basic authentication while providing a security problems inherent in Basic authentication while providing a
level of authentication which is useful in a wide range of scenarios. level of authentication which is useful in a wide range of scenarios.
17.2. Denial of Service 20.2. Denial of Service
Denial of service attacks are of special concern to WebDAV servers. Denial of service attacks are of special concern to WebDAV servers.
WebDAV plus HTTP enables denial of service attacks on every part of a WebDAV plus HTTP enables denial of service attacks on every part of a
system's resources. system's resources.
The underlying storage can be attacked by PUTting extremely large o The underlying storage can be attacked by PUTting extremely large
files. files.
Asking for recursive operations on large collections can attack o Asking for recursive operations on large collections can attack
processing time. processing time.
Making multiple pipelined requests on multiple connections can attack o Making multiple pipelined requests on multiple connections can
network connections. attack network connections.
WebDAV servers need to be aware of the possibility of a denial of WebDAV servers need to be aware of the possibility of a denial of
service attack at all levels. service attack at all levels. The proper response to such an attack
MAY be to simply drop the connection, or if the server is able to
make a response, the server MAY use a 400-level status request such
as 400 (Bad Request) and indicate why the request was refused (a 500-
level status response would indicate that the problem is with the
server, whereas unintentional DOS attacks are something the client is
capable of remedying).
17.3. Security through Obscurity 20.3. Security through Obscurity
WebDAV provides, through the PROPFIND method, a mechanism for listing WebDAV provides, through the PROPFIND method, a mechanism for listing
the member resources of a collection. This greatly diminishes the the member resources of a collection. This greatly diminishes the
effectiveness of security or privacy techniques that rely only on the effectiveness of security or privacy techniques that rely only on the
difficulty of discovering the names of network resources. Users of difficulty of discovering the names of network resources. Users of
WebDAV servers are encouraged to use access control techniques to WebDAV servers are encouraged to use access control techniques to
prevent unwanted access to resources, rather than depending on the prevent unwanted access to resources, rather than depending on the
relative obscurity of their resource names. relative obscurity of their resource names.
17.4. Privacy Issues Connected to Locks 20.4. Privacy Issues Connected to Locks
When submitting a lock request a user agent may also submit an owner When submitting a lock request a user agent may also submit an
XML field giving contact information for the person taking out the 'owner' XML field giving contact information for the person taking
lock (for those cases where a person, rather than a robot, is taking out the lock (for those cases where a person, rather than a robot, is
out the lock). This contact information is stored in a lockdiscovery taking out the lock). This contact information is stored in a DAV:
property on the resource, and can be used by other collaborators to lockdiscovery property on the resource, and can be used by other
begin negotiation over access to the resource. However, in many collaborators to begin negotiation over access to the resource.
cases this contact information can be very private, and should not be However, in many cases this contact information can be very private,
widely disseminated. Servers SHOULD limit read access to the and should not be widely disseminated. Servers SHOULD limit read
lockdiscovery property as appropriate. Furthermore, user agents access to the DAV:lockdiscovery property as appropriate.
SHOULD provide control over whether contact information is sent at Furthermore, user agents SHOULD provide control over whether contact
all, and if contact information is sent, control over exactly what information is sent at all, and if contact information is sent,
information is sent. control over exactly what information is sent.
17.5. Privacy Issues Connected to Properties 20.5. Privacy Issues Connected to Properties
Since property values are typically used to hold information such as Since property values are typically used to hold information such as
the author of a document, there is the possibility that privacy the author of a document, there is the possibility that privacy
concerns could arise stemming from widespread access to a resource's concerns could arise stemming from widespread access to a resource's
property data. To reduce the risk of inadvertent release of private property data. To reduce the risk of inadvertent release of private
information via properties, servers are encouraged to develop access information via properties, servers are encouraged to develop access
control mechanisms that separate read access to the resource body and control mechanisms that separate read access to the resource body and
read access to the resource's properties. This allows a user to read access to the resource's properties. This allows a user to
control the dissemination of their property data without overly control the dissemination of their property data without overly
restricting access to the resource's contents. restricting access to the resource's contents.
17.6. Reduction of Security due to Source Link 20.6. Implications of XML Entities
HTTP/1.1 warns against providing read access to script code because
it may contain sensitive information. Yet WebDAV, via its source
link facility, can potentially provide a URI for script resources so
they may be authored. For HTTP/1.1, a server could reasonably
prevent access to source resources due to the predominance of read-
only access. WebDAV, with its emphasis on authoring, encourages read
and write access to source resources, and provides the source link
facility to identify the source. This reduces the security benefits
of eliminating access to source resources. Users and administrators
of WebDAV servers should be very cautious when allowing remote
authoring of scripts, limiting read and write access to the source
resources to authorized principals.
17.7. Implications of XML External Entities
XML supports a facility known as "external entities", defined in XML supports a facility known as "external entities", defined in
section 4.2.2 of [REC-XML], which instruct an XML processor to Section 4.2.2 of [REC-XML], which instruct an XML processor to
retrieve and perform an inline include of XML located at a particular retrieve and include additional XML. An external XML entity can be
URI. An external XML entity can be used to append or modify the used to append or modify the document type declaration (DTD)
document type declaration (DTD) associated with an XML document. An associated with an XML document. An external XML entity can also be
external XML entity can also be used to include XML within the used to include XML within the content of an XML document. For non-
content of an XML document. For non-validating XML, such as the XML validating XML, such as the XML used in this specification, including
used in this specification, including an external XML entity is not an external XML entity is not required by XML. However, XML does
required by [REC-XML]. However, [REC-XML] does state that an XML state that an XML processor may, at its discretion, include the
processor may, at its discretion, include the external XML entity. external XML entity.
External XML entities have no inherent trustworthiness and are External XML entities have no inherent trustworthiness and are
subject to all the attacks that are endemic to any HTTP GET request. subject to all the attacks that are endemic to any HTTP GET request.
Furthermore, it is possible for an external XML entity to modify the Furthermore, it is possible for an external XML entity to modify the
DTD, and hence affect the final form of an XML document, in the worst DTD, and hence affect the final form of an XML document, in the worst
case significantly modifying its semantics, or exposing the XML case significantly modifying its semantics, or exposing the XML
processor to the security risks discussed in [RFC2376]. Therefore, processor to the security risks discussed in [RFC3023]. Therefore,
implementers must be aware that external XML entities should be implementers must be aware that external XML entities should be
treated as untrustworthy. treated as untrustworthy. If a server implementor chooses not to
handle external XML entities, it SHOULD respond to requests
containing external entities with the 'no-external-entities'
condition code.
There is also the scalability risk that would accompany a widely There is also the scalability risk that would accompany a widely
deployed application which made use of external XML entities. In deployed application which made use of external XML entities. In
this situation, it is possible that there would be significant this situation, it is possible that there would be significant
numbers of requests for one external XML entity, potentially numbers of requests for one external XML entity, potentially
overloading any server which fields requests for the resource overloading any server which fields requests for the resource
containing the external XML entity. containing the external XML entity.
17.8. Risks Connected with Lock Tokens Furthermore, there's also a risk based on the evaluation of "internal
entities" as defined in Section 4.2.2 of [REC-XML]. A small,
carefully crafted request using nested internal entities may require
enormous amounts of memory and/or processing time to process. Server
implementors should be aware of this risk and configure their XML
parsers so that requests like these can be detected and rejected as
early as possible.
This specification, in Section 6.4, requires the use of Universal 20.7. Risks Connected with Lock Tokens
Unique Identifiers (UUIDs) for lock tokens, in order to guarantee
their uniqueness across space and time. UUIDs, as defined in This specification encourages the use of "A Universally Unique
[ISO-11578], contain a "node" field which "consists of the IEEE Identifier (UUID) URN Namespace" ([RFC4122]) for lock tokens
address, usually the host address. For systems with multiple IEEE (Section 6.5), in order to guarantee their uniqueness across space
802 nodes, any available node address can be used." Since a WebDAV and time. Version 1 UUIDs (defined in Section 4) MAY contain a
server will issue many locks over its lifetime, the implication is "node" field that "consists of an IEEE 802 MAC address, usually the
that it will also be publicly exposing its IEEE 802 address. host address. For systems with multiple IEEE addresses, any
available one can be used". Since a WebDAV server will issue many
locks over its lifetime, the implication is that it may also be
publicly exposing its IEEE 802 address.
There are several risks associated with exposure of IEEE 802 There are several risks associated with exposure of IEEE 802
addresses. Using the IEEE 802 address: addresses. Using the IEEE 802 address:
o It is possible to track the movement of hardware from subnet to o It is possible to track the movement of hardware from subnet to
subnet. subnet.
o It may be possible to identify the manufacturer of the hardware o It may be possible to identify the manufacturer of the hardware
running a WebDAV server. running a WebDAV server.
o It may be possible to determine the number of each type of o It may be possible to determine the number of each type of
computer running WebDAV. computer running WebDAV.
Section 6.4.1 of this specification details an alternate mechanism This risk only applies to host address based UUID versions. Section
for generating the "node" field of a UUID without using an IEEE 802 4 of [RFC4122] describes several other mechanisms for generating
address, which alleviates the risks associated with exposure of IEEE UUIDs that do not involve the host address and therefore do not
802 addresses by using an alternate source of uniqueness. suffer from this risk.
18. IANA Considerations 20.8. Hosting Malicious Content
This document defines two namespaces, the namespace of property HTTP has the ability to host programs which are executed on client
names, and the namespace of WebDAV-specific XML elements used within machines. These programs can take many forms including web scripts,
property values. URIs are used for both names, for several reasons. executables, plug in modules, and macros in documents. WebDAV does
Assignment of a URI does not require a request to a central naming not change any of the security concerns around these programs yet
authority, and hence allow WebDAV property names and XML elements to often WebDAV is used in contexts where a wide range of users can
be quickly defined by any WebDAV user or application. URIs also publish documents on a server. The server might not have a close
provide a unique address space, ensuring that the distributed users trust relationship with the author that is publishing the document.
of WebDAV will not have collisions among the property names and XML Servers that allow clients to publish arbitrary content can usefully
elements they create. implement precautions to check that content published to the server
is not harmful to other clients. Servers could do this by techniques
such as restricting the types of content that is allowed to be
published and running virus and malware detection software on
published content. Servers can also mitigate the risk by having
appropriate access restriction and authentication of users that are
allowed to publish content to the server.
This specification defines a distinguished set of property names and 21. IANA Considerations
XML elements that are understood by all WebDAV applications. The
property names and XML elements in this specification are all derived
from the base URI DAV: by adding a suffix to this URI, for example,
DAV:creationdate for the "creationdate" property.
This specification also defines a URI scheme for the encoding of lock 21.1. New URI Schemes
tokens, the opaquelocktoken URI scheme described in Section 6.4.
To ensure correct interoperation based on this specification, IANA This specification defines two URI schemes:
must reserve the URI namespaces starting with "DAV:" and with
"opaquelocktoken:" for use by this specification, its revisions, and
related WebDAV specifications.
19. Intellectual Property 1. the "opaquelocktoken" scheme defined in Appendix C, and
The following notice is copied from RFC 2026 [RFC2026], section 10.4, 2. the "DAV" URI scheme, which historically was used in [RFC2518] to
and describes the position of the IETF concerning intellectual disambiguate WebDAV property and XML element names and which
property claims made against this document. continues to be used for that purpose in this specification and
others extending WebDAV. Creation of identifiers in the "DAV:"
namespace is controlled by the IETF.
The IETF takes no position regarding the validity or scope of any Note that defining new URI schemes for XML namespaces is now
intellectual property or other rights that might be claimed to discouraged. "DAV:" was defined before standard best practices
pertain to the implementation or use other technology described in emerged.
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any 21.2. XML Namespaces
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
20. Acknowledgements XML namespaces disambiguate WebDAV property names and XML elements.
Any WebDAV user or application can define a new namespace in order to
create custom properties or extend WebDAV XML syntax. IANA does not
need to manage such namespaces, property names or element names.
21.3. Message Header Fields
The message header fields below should be added to the permanent
registry (see [RFC3864]).
21.3.1. DAV
Header field name: DAV
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.1)
21.3.2. Depth
Header field name: Depth
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.2)
21.3.3. Destination
Header field name: Destination
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.3)
21.3.4. If
Header field name: If
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.4)
21.3.5. Lock-Token
Header field name: Lock-Token
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.5)
21.3.6. Overwrite
Header field name: Overwrite
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.6)
21.3.7. Timeout
Header field name: Timeout
Applicable protocol: http
Status: standard
Author/Change controller: IETF
Specification document: this specification (Section 10.7)
22. Acknowledgements
A specification such as this thrives on piercing critical review and A specification such as this thrives on piercing critical review and
withers from apathetic neglect. The authors gratefully acknowledge withers from apathetic neglect. The authors gratefully acknowledge
the contributions of the following people, whose insights were so the contributions of the following people, whose insights were so
valuable at every stage of our work. valuable at every stage of our work.
Contributors to RFC2518
Terry Allen, Harald Alvestrand, Jim Amsden, Becky Anderson, Alan Terry Allen, Harald Alvestrand, Jim Amsden, Becky Anderson, Alan
Babich, Sanford Barr, Dylan Barrell, Bernard Chester, Tim Berners- Babich, Sanford Barr, Dylan Barrell, Bernard Chester, Tim Berners-
Lee, Dan Connolly, Jim Cunningham, Ron Daniel, Jr., Jim Davis, Keith Lee, Dan Connolly, Jim Cunningham, Ron Daniel, Jr., Jim Davis, Keith
Dawson, Mark Day, Brian Deen, Martin Duerst, David Durand, Lee Dawson, Mark Day, Brian Deen, Martin Duerst, David Durand, Lee
Farrell, Chuck Fay, Wesley Felter, Roy Fielding, Mark Fisher, Alan Farrell, Chuck Fay, Wesley Felter, Roy Fielding, Mark Fisher, Alan
Freier, George Florentine, Jim Gettys, Phill Hallam-Baker, Dennis Freier, George Florentine, Jim Gettys, Phill Hallam-Baker, Dennis
Hamilton, Steve Henning, Mead Himelstein, Alex Hopmann, Andre van der Hamilton, Steve Henning, Mead Himelstein, Alex Hopmann, Andre van der
Hoek, Ben Laurie, Paul Leach, Ora Lassila, Karen MacArthur, Steven Hoek, Ben Laurie, Paul Leach, Ora Lassila, Karen MacArthur, Steven
Martin, Larry Masinter, Michael Mealling, Keith Moore, Thomas Narten, Martin, Larry Masinter, Michael Mealling, Keith Moore, Thomas Narten,
Henrik Nielsen, Kenji Ota, Bob Parker, Glenn Peterson, Jon Radoff, Henrik Nielsen, Kenji Ota, Bob Parker, Glenn Peterson, Jon Radoff,
skipping to change at page 90, line 27 skipping to change at page 124, line 40
Larry Masinter have been invaluable, both in helping the formation of Larry Masinter have been invaluable, both in helping the formation of
the working group and in patiently coaching the authors along the the working group and in patiently coaching the authors along the
way. In so many ways he has set high standards we have toiled to way. In so many ways he has set high standards we have toiled to
meet. The contributions of Judith Slein in clarifying the meet. The contributions of Judith Slein in clarifying the
requirements, and in patiently reviewing draft after draft, both requirements, and in patiently reviewing draft after draft, both
improved this specification and expanded our minds on document improved this specification and expanded our minds on document
management. management.
We would also like to thank John Turner for developing the XML DTD. We would also like to thank John Turner for developing the XML DTD.
21. References The authors of RFC2518 were Yaron Goland, Jim Whitehead, A. Faizi,
Steve Carter and D. Jensen. Although their names had to be removed
21.1. Normative References due to IETF author count restrictions they can take credit for the
majority of the design of WebDAV.
[RFC1766] Alvestrand, H., "Tags for the Identification of
Languages", RFC 1766, March 1995.
[RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
Languages", BCP 18, RFC 2277, January 1998.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifiers (URI): Generic Syntax", RFC 2396,
August 1998.
[REC-XML] Bray, T., Paoli, J., and C. Sperberg-McQueen, "Extensible
Markup Language (XML) 1.0", W3C REC-xml-19980210,
February 1998,
<http://www.w3.org/TR/1998/REC-xml-19980210>.
[REC-XML-NAMES]
Bray, T., Hollander, D., and A. Layman, "Namespaces in
XML", W3C REC-xml-names-19990114, January 1999,
<http://www.w3.org/TR/1999/REC-xml-names-19990114>.
[RFC2069] Franks, J., Hallam-Baker, P., Hostetler, J., Leach, P.,
Luotonen, A., Sink, E., and L. Stewart, "An Extension to
HTTP : Digest Access Authentication", RFC 2069,
January 1997.
[RFC2068] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., and T.
Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1",
RFC 2068, January 1997.
[ISO-639] International Organization for Standardization, "ISO 639:
1988. Code for the representation of names of languages.",
1988.
[ISO-8601]
International Organization for Standardization, "ISO 8601,
Data elements and interchange formats-Information
interchange--Representation of dates and times",
June 1988.
[ISO-11578]
International Organization for Standardization, "ISO/IEC
11578:1996. Information technology - Open Systems
Interconnection - Remote Procedure Call (RPC)", 1996.
[RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.
[UTF-8] Yergeau, F., "UTF-8, a transformation format of ISO
10646", RFC 2279, January 1998.
21.2. Informational References
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.
[RFC1807] Lasher, R. and D. Cohen, "A Format for Bibliographic
Records", RFC 1807, June 1995.
[WF] Lagoze, C., "The Warwick Framework: A Container
Architecture for Diverse Sets of Metadata", July 1996,
<http://www.dlib.org/dlib/july96/lagoze/07lagoze.html>.
D-Lib Magazine, July/August 1996.
[USMARC] Network Development and MARC Standards, Office, Washington
DC: Cataloging Distribution Service, Library of Congress.,
"USMARC Format for Bibliographic Data", 1994.
[REC-PICS]
Miller, J., Krauskopf, T., Resnick, P., and W. Treese,
"PICS Label Distribution Label Syntax and Communication
Protocols, Version 1.1", W3C REC-PICS-labels-961031,
October 1996,
<http://www.w3.org/pub/WWW/TR/
REC-PICS-labels-961031.html>.
[RFC2291] Slein, J., Vitali, F., Whitehead, E., and D. Durand,
"Requirements for a Distributed Authoring and Versioning
Protocol for the World Wide Web", RFC 2291, February 1998.
[RFC2413] Weibel, S., Kunze, J., Lagoze, C., and M. Wolf, "Dublin Additional Acknowledgements for This Specification
Core Metadata for Resource Discovery", RFC 2413,
September 1998.
[RFC2376] Whitehead, E. and M. Makoto, "XML Media Types", RFC 2376, Significant contributors of text for this specification are listed as
July 1998. contributors in the section below. We must also gratefully
acknowledge Geoff Clemm, Joel Soderberg, and Dan Brotsky for hashing
out specific text on the list or in meetings. Joe Hildebrand and
Cullen Jennings helped close many issues. Barry Lind described an
additional security consideration and Cullen Jennings provided text
for that consideration. Jason Crawford tracked issue status for this
document for a period of years, followed by Elias Sinderson.
Appendix A. Appendices 23. Contributors to This Specification
A.1. Appendix 1 - WebDAV Document Type Definition Julian Reschke,
<green/>bytes GmbH,
Hafenweg 16, 48155 Muenster, Germany,
Email: julian.reschke@greenbytes.de
This section provides a document type definition, following the rules Elias Sinderson
in [REC-XML], for the XML elements used in the protocol stream and in University of California, Santa Cruz
the values of properties. It collects the element definitions given 1156 High Street, Santa Cruz, CA 95064
in sections 12 and 13. Email: elias@cse.ucsc.edu
<!DOCTYPE webdav-1.0 [ Jim Whitehead,
University of California, Santa Cruz
1156 High Street, Santa Cruz, CA 95064
Email: ejw@soe.ucsc.edu
<!--============ XML Elements from Section 12 ==================--> 24. Authors of RFC2518
<!ELEMENT activelock (lockscope, locktype, depth, owner?, timeout?, Y. Y. Goland,
locktoken?) > Microsoft Corporation,
One Microsoft Way,
Redmond, WA 98052-6399.
Email: yarong@microsoft.com.
<!ELEMENT lockentry (lockscope, locktype) > E. J. Whitehead, Jr.,
<!ELEMENT lockinfo (lockscope, locktype, owner?) > Dept. Of Information and Computer Science,
University of California, Irvine,
Irvine, CA 92697-3425.
Email: ejw@ics.uci.edu.
<!ELEMENT locktype (write) > A. Faizi,
<!ELEMENT write EMPTY > Netscape,
685 East Middlefield Road,
Mountain View, CA 94043.
Email: asad@netscape.com.
<!ELEMENT lockscope (exclusive | shared) > S. R. Carter,
<!ELEMENT exclusive EMPTY > Novell,
<!ELEMENT shared EMPTY > 1555 N. Technology Way,
<!ELEMENT depth (#PCDATA) > M/S ORM F111,
Orem, UT 84097-2399.
Email: srcarter@novell.com.
<!ELEMENT owner ANY > D. Jensen,
Novell,
1555 N. Technology Way,
M/S ORM F111,
Orem, UT 84097-2399.
Email: dcjensen@novell.com.
<!ELEMENT timeout (#PCDATA) > 25. References
<!ELEMENT locktoken (href+) > 25.1. Normative References
<!ELEMENT href (#PCDATA) > [REC-XML] Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Third
Edition)", W3C REC-xml-20040204, February 2004,
<http://www.w3.org/TR/2004/REC-xml-20040204>.
<!ELEMENT link (src+, dst+) > [REC-XML-INFOSET]
<!ELEMENT dst (#PCDATA) > Cowan, J. and R. Tobin, "XML Information Set (Second
<!ELEMENT src (#PCDATA) > Edition)", W3C REC-xml-infoset-20040204, February 2004,
<http://www.w3.org/TR/2004/REC-xml-infoset-20040204/>.
<!ELEMENT multistatus (response+, responsedescription?) > [REC-XML-NAMES]
Bray, T., Hollander, D., and A. Layman, "Namespaces in
XML", W3C REC-xml-names-19990114, January 1999,
<http://www.w3.org/TR/1999/REC-xml-names-19990114>.
<!ELEMENT response (href, ((href*, status)|(propstat+)), [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
responsedescription?) > Requirement Levels", BCP 14, RFC 2119, March 1997.
<!ELEMENT status (#PCDATA) >
<!ELEMENT propstat (prop, status, responsedescription?) >
<!ELEMENT responsedescription (#PCDATA) >
<!ELEMENT prop ANY > [RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
Languages", BCP 18, RFC 2277, January 1998.
<!ELEMENT propertybehavior (omit | keepalive) > [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
<!ELEMENT omit EMPTY > Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
<!ELEMENT keepalive (#PCDATA | href+) > [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A., and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication",
RFC 2617, June 1999.
<!ELEMENT propertyupdate (remove | set)+ > [RFC3339] Klyne, G., Ed. and C. Newman, "Date and Time on the
<!ELEMENT remove (prop) > Internet: Timestamps", RFC 3339, July 2002.
<!ELEMENT set (prop) >
<!ELEMENT propfind (allprop | propname | prop) > [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
<!ELEMENT allprop EMPTY > 10646", STD 63, RFC 3629, November 2003.
<!ELEMENT propname EMPTY >
<!ELEMENT collection EMPTY > [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
<!--=========== Property Elements from Section 13 ===============--> [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
<!ELEMENT creationdate (#PCDATA) > Unique IDentifier (UUID) URN Namespace", RFC 4122,
<!ELEMENT displayname (#PCDATA) > July 2005.
<!ELEMENT getcontentlanguage (#PCDATA) >
<!ELEMENT getcontentlength (#PCDATA) >
<!ELEMENT getcontenttype (#PCDATA) >
<!ELEMENT getetag (#PCDATA) >
<!ELEMENT getlastmodified (#PCDATA) >
<!ELEMENT lockdiscovery (activelock)* >
<!ELEMENT resourcetype ANY >
<!ELEMENT source (link)* >
<!ELEMENT supportedlock (lockentry)* >
]>
A.2. Appendix 2 - ISO 8601 Date and Time Profile 25.2. Informational References
The creationdate property specifies the use of the ISO 8601 date [RFC2291] Slein, J., Vitali, F., Whitehead, E., and D. Durand,
format [ISO-8601]. This section defines a profile of the ISO 8601 "Requirements for a Distributed Authoring and Versioning
date format for use with this specification. This profile is quoted Protocol for the World Wide Web", RFC 2291, February 1998.
from an Internet-Draft by Chris Newman, and is mentioned here to
properly attribute his work.
date-time = full-date "T" full-time [RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D.
Jensen, "HTTP Extensions for Distributed Authoring --
WEBDAV", RFC 2518, February 1999.
full-date = date-fullyear "-" date-month "-" date-mday [RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media
full-time = partial-time time-offset Types", RFC 3023, January 2001.
date-fullyear = 4DIGIT [RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J.
date-month = 2DIGIT ; 01-12 Whitehead, "Versioning Extensions to WebDAV
date-mday = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on (Web Distributed Authoring and Versioning)", RFC 3253,
month/year March 2002.
time-hour = 2DIGIT ; 00-23
time-minute = 2DIGIT ; 00-59
time-second = 2DIGIT ; 00-59, 00-60 based on leap second rules
time-secfrac = "." 1*DIGIT
time-numoffset = ("+" / "-") time-hour ":" time-minute
time-offset = "Z" / time-numoffset
partial-time = time-hour ":" time-minute ":" time-second [RFC3648] Whitehead, J. and J. Reschke, Ed., "Web Distributed
[time-secfrac] Authoring and Versioning (WebDAV) Ordered Collections
Protocol", RFC 3648, December 2003.
Numeric offsets are calculated as local time minus UTC (Coordinated [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web
Universal Time). So the equivalent time in UTC can be determined by Distributed Authoring and Versioning (WebDAV) Access
subtracting the offset from the local time. For example, 18:50:00- Control Protocol", RFC 3744, May 2004.
04:00 is the same time as 22:58:00Z.
If the time in UTC is known, but the offset to local time is unknown, [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration
this can be represented with an offset of "-00:00". This differs Procedures for Message Header Fields", BCP 90, RFC 3864,
from an offset of "Z" which implies that UTC is the preferred September 2004.
reference point for the specified time.
A.3. Appendix 3 - Notes on Processing XML Elements Appendix A. Notes on Processing XML Elements
A.3.1. Notes on Empty XML Elements A.1. Notes on Empty XML Elements
XML supports two mechanisms for indicating that an XML element does XML supports two mechanisms for indicating that an XML element does
not have any content. The first is to declare an XML element of the not have any content. The first is to declare an XML element of the
form <A></A>. The second is to declare an XML element of the form form <A></A>. The second is to declare an XML element of the form
<A/>. The two XML elements are semantically identical. <A/>. The two XML elements are semantically identical.
It is a violation of the XML specification to use the <A></A> form if A.2. Notes on Illegal XML Processing
the associated DTD declares the element to be EMPTY (e.g., <!ELEMENT
A EMPTY>). If such a statement is included, then the empty element
format, <A/> must be used. If the element is not declared to be
EMPTY, then either form <A></A> or <A/> may be used for empty
elements.
A.3.2. Notes on Illegal XML Processing
XML is a flexible data format that makes it easy to submit data that XML is a flexible data format that makes it easy to submit data that
appears legal but in fact is not. The philosophy of "Be flexible in appears legal but in fact is not. The philosophy of "Be flexible in
what you accept and strict in what you send" still applies, but it what you accept and strict in what you send" still applies, but it
must not be applied inappropriately. XML is extremely flexible in must not be applied inappropriately. XML is extremely flexible in
dealing with issues of white space, element ordering, inserting new dealing with issues of white space, element ordering, inserting new
elements, etc. This flexibility does not require extension, elements, etc. This flexibility does not require extension,
especially not in the area of the meaning of elements. especially not in the area of the meaning of elements.
There is no kindness in accepting illegal combinations of XML There is no kindness in accepting illegal combinations of XML
elements. At best it will cause an unwanted result and at worst it elements. At best it will cause an unwanted result and at worst it
can cause real damage. can cause real damage.
A.3.2.1. Example - XML Syntax Error A.3. Example - XML Syntax Error
The following request body for a PROPFIND method is illegal. The following request body for a PROPFIND method is illegal.
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:"> <D:propfind xmlns:D="DAV:">
<D:allprop/> <D:allprop/>
<D:propname/> <D:propname/>
</D:propfind> </D:propfind>
The definition of the propfind element only allows for the allprop or The definition of the propfind element only allows for the allprop or
the propname element, not both. Thus the above is an error and must the propname element, not both. Thus the above is an error and must
be responded to with a 400 (Bad Request). be responded to with a 400 (Bad Request).
Imagine, however, that a server wanted to be "kind" and decided to Imagine, however, that a server wanted to be "kind" and decided to
pick the allprop element as the true element and respond to it. A pick the allprop element as the true element and respond to it. A
client running over a bandwidth limited line who intended to execute client running over a bandwidth limited line who intended to execute
a propname would be in for a big surprise if the server treated the a propname would be in for a big surprise if the server treated the
command as an allprop. command as an allprop.
Additionally, if a server were lenient and decided to reply to this Additionally, if a server were lenient and decided to reply to this
request, the results would vary randomly from server to server, with request, the results would vary randomly from server to server, with
some servers executing the allprop directive, and others executing some servers executing the allprop directive, and others executing
the propname directive. This reduces interoperability rather than the propname directive. This reduces interoperability rather than
increasing it. increasing it.
A.3.2.2. Example - Unknown XML Element A.4. Example - Unexpected XML Element
The previous example was illegal because it contained two elements The previous example was illegal because it contained two elements
that were explicitly banned from appearing together in the propfind that were explicitly banned from appearing together in the propfind
element. However, XML is an extensible language, so one can imagine element. However, XML is an extensible language, so one can imagine
new elements being defined for use with propfind. Below is the new elements being defined for use with propfind. Below is the
request body of a PROPFIND and, like the previous example, must be request body of a PROPFIND and, like the previous example, must be
rejected with a 400 (Bad Request) by a server that does not rejected with a 400 (Bad Request) by a server that does not
understand the expired-props element. understand the expired-props element.
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:" <D:propfind xmlns:D="DAV:"
xmlns:E="http://www.foo.bar/standards/props/"> xmlns:E="http://www.example.com/standards/props/">
<E:expired-props/> <E:expired-props/>
</D:propfind> </D:propfind>
To understand why a 400 (Bad Request) is returned let us look at the To understand why a 400 (Bad Request) is returned let us look at the
request body as the server unfamiliar with expired-props sees it. request body as the server unfamiliar with expired-props sees it.
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:" <D:propfind xmlns:D="DAV:"
xmlns:E="http://www.foo.bar/standards/props/"> xmlns:E="http://www.example.com/standards/props/">
</D:propfind> </D:propfind>
As the server does not understand the expired-props element, As the server does not understand the 'expired-props' element,
according to the WebDAV-specific XML processing rules specified in according to the WebDAV-specific XML processing rules specified in
Section 14, it must ignore it. Thus the server sees an empty Section 17, it must process the request as if the element were not
propfind, which by the definition of the propfind element is illegal. there. Thus the server sees an empty propfind, which by the
definition of the propfind element is illegal.
Please note that had the extension been additive it would not Please note that had the extension been additive it would not
necessarily have resulted in a 400 (Bad Request). For example, necessarily have resulted in a 400 (Bad Request). For example,
imagine the following request body for a PROPFIND: imagine the following request body for a PROPFIND:
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:" <D:propfind xmlns:D="DAV:"
xmlns:E="http://www.foo.bar/standards/props/"> xmlns:E="http://www.example.com/standards/props/">
<D:propname/> <D:propname/>
<E:leave-out>*boss*</E:leave-out> <E:leave-out>*boss*</E:leave-out>
</D:propfind> </D:propfind>
The previous example contains the fictitious element leave-out. Its The previous example contains the fictitious element leave-out. Its
purpose is to prevent the return of any property whose name matches purpose is to prevent the return of any property whose name matches
the submitted pattern. If the previous example were submitted to a the submitted pattern. If the previous example were submitted to a
server unfamiliar with leave-out, the only result would be that the server unfamiliar with 'leave-out', the only result would be that the
leave-out element would be ignored and a propname would be executed. 'leave-out' element would be ignored and a propname would be
executed.
A.4. Appendix 4 -- XML Namespaces for WebDAV Appendix B. Notes on HTTP Client Compatibility
A.4.1. Introduction WebDAV was designed to be, and has been found to be, backward-
compatible with HTTP 1.1. The PUT and DELETE methods are defined in
HTTP and thus may be used by HTTP clients as well as WebDAV-aware
clients, but the responses to PUT and DELETE have been extended in
this specification in ways that only a WebDAV client would be
entirely prepared for. Some theoretical concerns were raised about
whether those responses would cause interoperability problems with
HTTP-only clients, and this section addresses those concerns.
All DAV compliant systems MUST support the XML namespace extensions Since any HTTP client ought to handle unrecognized 400-level and 500-
as specified in [REC-XML-NAMES]. level status codes as errors, the following new status codes should
not present any issues: 422, 423 and 507 (424 is also a new status
code but it appears only in the body of a Multistatus response.) So,
for example, if a HTTP client attempted to PUT or DELETE a locked
resource, the 423 Locked response ought to result in a generic error
presented to the user.
A.4.2. Meaning of Qualified Names The 207 Multistatus response is interesting because a HTTP client
issuing a DELETE request to a collection might interpret a 207
response as a success, even though it does not realize the resource
is a collection and cannot understand that the DELETE operation might
have been a complete or partial failure. That interpretation isn't
entirely justified, because a 200-level response indicates that the
server "received, understood and accepted" the request, not that the
request resulted in complete success.
[Note to the reader: This section does not appear in [REC-XML-NAMES], One option is that a server could treat a DELETE of a collection as
but is necessary to avoid ambiguity for WebDAV XML processors.] an atomic operation, and use either 204 No Content in case of
success, or some appropriate error response (400 or 500 level) for an
error. This approach would indeed maximize backward compatibility.
However, since interoperability tests and working group discussions
have not turned up any instances of HTTP clients issuing a DELETE
request against a WebDAV collection, this concern is more theoretical
than practical. Thus, servers are likely to be completely successful
at interoperating with HTTP clients even if they treat any collection
DELETE request as a WebDAV request and send a 207 Multistatus
response.
WebDAV compliant XML processors MUST interpret a qualified name as a In general server implementations are encouraged to use the detailed
URI constructed by appending the LocalPart to the namespace name URI. responses and other mechanisms defined in this document rather than
make changes for theoretical interoperability concerns.
Example Appendix C. The 'opaquelocktoken' Scheme and URIs
<del:glider xmlns:del="http://www.del.jensen.org/"> The 'opaquelocktoken' URI scheme was defined in [RFC2518] (and
<del:glidername> registered by IANA) in order to create syntactically correct and
Johnny Updraft easy-to-generate URIs out of UUIDs, intended to be used as lock
</del:glidername> tokens and to be unique across all resources for all time.
<del:glideraccidents/>
</del:glider>
In this example, the qualified element name "del:glider" is An opaquelocktoken URI is constructed by concatenating the
interpreted as the URL "http://www.del.jensen.org/glider". 'opaquelocktoken' scheme with a UUID, along with an optional
extension. Servers can create new UUIDs for each new lock token. If
a server wishes to reuse UUIDs the server MUST add an extension and
the algorithm generating the extension MUST guarantee that the same
extension will never be used twice with the associated UUID.
<bar:glider xmlns:del="http://www.del.jensen.org/"> OpaqueLockToken-URI = "opaquelocktoken:" UUID [Extension]
<bar:glidername> ; UUID is defined in Section 3 of [RFC4122]. Note that LWS
Johnny Updraft ; is not allowed between elements of
</bar:glidername> ; this production.
<bar:glideraccidents/>
</bar:glider>
Even though this example is syntactically different from the previous Extension = path
example, it is semantically identical. Each instance of the ; path is defined in Section 3.3 of [RFC3986]
namespace name "bar" is replaced with "http://www.del.jensen.org/"
and then appended to the local name for each element tag. The
resulting tag names in this example are exactly the same as for the
previous example.
<foo:r xmlns:foo="http://www.del.jensen.org/glide"> Appendix D. Lock-null Resources
<foo:rname>
Johnny Updraft
</foo:rname>
<foo:raccidents/>
</foo:r>
This example is semantically identical to the two previous ones. The original WebDAV model for locking unmapped URLs created "lock-
Each instance of the namespace name "foo" is replaced with null resources". This model was over-complicated and some
"http://www.del.jensen.org/glide" which is then appended to the local interoperability and implementation problems were discovered. The
name for each element tag, the resulting tag names are identical to new WebDAV model for locking unmapped URLs (see Section 7.3) creates
those in the previous examples. "locked empty resources". Lock-null resources are deprecated. This
section discusses the original model briefly because clients MUST be
able to handle either model.
Index In the original "lock-null resource" model, which is no longer
recommended for implementation:
1 o A lock-null resource sometimes appeared as "Not Found". The
102 Processing (status code) 61-62 server responds with a 404 or 405 to any method except for PUT,
MKCOL, OPTIONS, PROPFIND, LOCK, UNLOCK.
2 o A lock-null resource does however show up as a member of its
207 Multi-Status (status code) 63-64 parent collection.
4 o The server removes the lock-null resource entirely (its URI
422 Unprocessable Entity (status code) 63 becomes unmapped) if its lock goes away before it is converted to
423 Locked (status code) 63 a regular resource. Recall that locks go away not only when they
424 Failed Dependency (status code) 63 expire or are unlcoked, but are also removed if a resource is
renamed or moved, or if any parent collection is renamed or moved.
5 o The server converts the lock-null resource into a regular resource
507 Insufficient Storage (status code) 63 if a PUT request to the URL is successful.
A o The server converts the lock-null resource into a collection if a
activelock MKCOL request to the URL is successful (though interoperability
XML element 64 experience showed that not all servers followed this requirement).
allprop
XML element 74
C o Property values were defined for DAV:lockdiscovery and DAV:
Collection 8 supportedlock properties but not necessarily for other properties
COPY method 39 like DAV:getcontenttype.
D Clients can easily interoperate both with servers that support the
DAV header 56 old model "lock-null resources" and the recommended model of "locked
compliance class '1' 83 empty resources" by only attempting PUT after a LOCK to an unmapped
compliance class '2' 83 URL, not MKCOL or GET.
DAV:collection resource type 65
DAV:creationdate property 75
DAV:displayname property 75
DAV:getcontentlanguage property 75
DAV:getcontentlength property 76
DAV:getcontenttype property 76
DAV:getetag property 76
DAV:getlastmodified property 77
DAV:lockdiscovery property 77
DAV:resourcetype property 79
DAV:source property 80
DAV:supportedlock property 81
Dead Property 8
DELETE method 37
depth
XML element 64
Depth header 56
Destination header 57
dst
XML element 66
E D.1. Guidance for Clients Using LOCK to Create Resources
exclusive
XML element 68
H A WebDAV client implemented to this specification might find servers
Headers that create lock-null resources (implemented before this
DAV 56 specification using [RFC2518]) as well as servers that create locked
Depth 56 empty resources. The response to the LOCK request will not indicate
Destination 57 what kind of resource was created. There are a few techniques which
If 57 help the client deal with either type.
Lock-Token 60
Overwrite 60
Status-URI 61
Timeout 61
href
XML element 65
I If the client wishes to avoid accidentally creating either lock-
If header 57 null or empty locked resources, an "If-Match: *" header can be
Internal Member URI 8 included with LOCK requests to prevent the server from creating a
new resource.
K If a LOCK request creates a resource and the client subsequently
keepalive wants to overwrite that resource using a COPY or MOVE request, the
XML element 71 client should include an "Overwrite: T" header.
L If a LOCK request creates a resource and the client then decides
link to get rid of that resource, a DELETE request is supposed to fail
XML element 66 on a lock-null resource and UNLOCK should be used instead. But
Live Property 8 with a locked empty resource, UNLOCK doesn't make the resource
LOCK method 48 disappear. Therefore, the client might have to try both requests
Lock-Token header 60 and ignore an error in one of the two requests.
lockentry
XML element 67
lockinfo
XML element 67
lockscope
XML element 67
locktoken
XML element 65
locktype
XML element 68
M Appendix E. Guidance for Clients Desiring to Authenticate
Member URI 8
Methods
COPY 39
DELETE 37
LOCK 48
MKCOL 35
MOVE 44
PROPFIND 24
PROPPATCH 33
PUT 39
UNLOCK 55
MKCOL method 35
MOVE method 44
multistatus
XML element 69
N Many WebDAV clients already implemented have account settings
Null Resource 8 (similar to the way email clients store IMAP account settings).
Thus, the WebDAV client would be able to authenticate with its first
couple requests to the server, provided it had a way to get the
authentication challenge from the server with realm name, nonce and
other challenge information. Note that the results of some requests
might vary according to whether the client is authenticated or not --
a PROPFIND might return more visible resources if the client is
authenticated, yet not fail if the client is anonymous.
O There are a number of ways the client might be able to trigger the
omit server do provide an authentication challenge. This appendix
XML element 72 describes a couple approaches that seem particularly likely to work.
Overwrite header 60
owner
XML element 70
P The first approach is to perform a request that ought to require
prop authentication. However, it's possible that a server might handle
XML element 71 any request even without authentication, so to be entirely safe the
Properties client could add a conditional header to ensure that even if the
DAV:creationdate 75 request passes permissions checks it's not actually handled by the
DAV:displayname 75 server. An example of following this approach would be to use a PUT
DAV:getcontentlanguage 75 request with an "If-Match" header with a made-up ETag value. This
DAV:getcontentlength 76 approach might fail to result in an authentication challenge if the
DAV:getcontenttype 76 server does not test authorization before testing conditionals as is
DAV:getetag 76 required (see Section 8.5), or if the server does not need to test
DAV:getlastmodified 77 authorization.
DAV:lockdiscovery 77
DAV:resourcetype 79
DAV:source 80
DAV:supportedlock 81
Property 8
propertybehaviour
XML element 71
propertyupdate
XML element 72
propfind
XML element 74
PROPFIND method 24
propname
XML element 74
PROPPATCH method 33
propstat
XML element 69
PUT method 39
R Example - forcing auth challenge with write request
remove
XML element 73
Resource Types
DAV:collection 65
response
XML element 69
responsedescription
XML element 70
S >>Request
set
XML element 73
shared
XML element 68
src
XML element 66
status
XML element 70
Status Codes
102 Processing 61-62
207 Multi-Status 63-64
422 Unprocessable Entity 63
423 Locked 63
424 Failed Dependency 63
507 Insufficient Storage 63
Status-URI header 61
T PUT /forceauth.txt HTTP/1.1
timeout Host: www.example.com
XML element 65 If-Match: "xxx"
Timeout header 61 Content-Type: text/plain
Content-Length: 0
U The second approach is to use an Authorization header (defined in
UNLOCK method 55 [RFC2617]) which is likely to be rejected by the server but which
URI 7 will then prompt a proper authentication challenge. For example, the
URL 7 client could start with a PROPFIND request containing an
Authorization header containing a made-up Basic userid:password
string or with actual plausible credentials. This approach relies on
the server responding with a "401 Unauthorized" along with a
challenge if it receives an Authorization header with an unrecognized
username, invalid password, or if it doesn't even handle Basic
authentication. This seems likely to work because of the
requirements of RFC2617:
W "If the origin server does not wish to accept the credentials sent
write with a request, it SHOULD return a 401 (Unauthorized) response. The
XML element 68 response MUST include a WWW-Authenticate header field containing at
least one (possibly new) challenge applicable to the requested
resource."
Authors' Addresses There's a slight problem with implementing that recommendation in
some cases, because some servers do not even have challenge
information for certain resources. Thus, when there's no way to
authenticate to a resource or the resource is entirely publicly
available over all accepted methods, the server MAY ignore the
Authorization header, and the client presumably try again later.
Y. Y. Goland Example - forcing auth challenge with Authorization header
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052-6399
Email: yarong@microsoft.com >>Request
E. J. Whitehead, Jr. PROPFIND /docs/ HTTP/1.1
Dept. Of Information and Computer Science, University of California, Irvine Host: www.example.com
Irvine, CA 92697-3425 Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
Content-type: application/xml; charset="utf-8"
Content-Length: xxxx
Email: ejw@ics.uci.edu [body omitted]
A. Faizi Appendix F. Summary of changes from RFC2518
Netscape
685 East Middlefield Road
Mountain View, CA 94043
Email: asad@netscape.com This section lists major changes between this document and RFC2518,
starting with those that are likely to result in implementation
changes. Servers will advertise support for all changes in this
specification by returning the compliance class "3" in the DAV
response header (see Sections 10.1 and 18.3).
S. R. Carter F.1. Changes for both Client and Server Implementations
Novell
1555 N. Technology Way
M/S ORM F111
Orem, UT 84097-2399
Email: srcarter@novell.com Collections and Namespace Operations
D. Jensen
Novell
1555 N. Technology Way
M/S ORM F111
Orem, UT 84097-2399
Email: dcjensen@novell.com o The semantics of PROPFIND 'allprop' (Section 9.1) have been
relaxed so that servers return results including, at a minimum,
the live properties defined in this specification, but not
necessarily return other live properties. The 'allprop' directive
therefore means something more like "return all properties that
are supposed to be returned when 'allprop' is requested" -- a set
of properties which may include custom properties and properties
defined in other specifications if those other specifications so
require. Related to this, 'allprop' requests can now be extended
with the 'include' syntax to include specific named properties,
thereby avoiding additional requests due to changed 'allprop'
semantics.
Full Copyright Statement o Servers are now allowed to reject PROPFIND requests with Depth:
Infinity. Clients that used this will need to be able to do a
series of Depth:1 requests instead.
Copyright (C) The Internet Society (1999). All Rights Reserved. o Multistatus response bodies now can transport the value of HTTP's
Location response header in the new 'location' element. Clients
may use this to avoid additional roundtrips to the server when
there is a 'response' element with a 3xx status (see
Section 14.24).
This document and translations of it may be copied and furnished to o The definition of COPY has been relaxed so that it doesn't require
others, and derivative works that comment on or otherwise explain it servers to first delete the target resources anymore (this was a
or assist in its implementation may be prepared, copied, published known incompatibility with [RFC3253]). See Section 9.8.
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be Headers and Marshalling
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an o The Destination and If request headers now allow absolute paths in
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING addition to full URIs (see Section 8.3). This may be useful for
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING clients operating through a reverse proxy that does rewrite the
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION Host request header, but not WebDAV-specific headers.
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. o This specification adopts the error marshalling extensions and the
"precondition/postcondition" terminology defined in [RFC3253] (see
Section 16). Related to that, it adds the "error" XML element
inside multistatus response bodies (see Section 14.5, however note
that it uses a format different from the one recommend in
RFC3253).
o Senders and recipients are now required to support the UTF-16
character encoding in XML message bodies (see Section 19).
o Clients are now required to send the Depth header on PROPFIND
requests, although servers are still encouraged to support clients
that don't.
Locking
o RFC2518's concept of "lock-null resources" (LNRs) has been
replaced by a simplified approach, the "locked empty resources"
(see Section 7.3). There are some aspects of lock-null resources
clients can not rely on anymore, namely the ability to use them to
create a locked collection or the fact that they disappear upon
UNLOCK when no PUT or MKCOL request was issued. Note that servers
are still allowed to implement LNRs as per RFC2518.
o There is no implicit refresh of locks anymore. Locks are only
refreshed upon explicit request (see Section 9.10.2).
o Clarified that the DAV:owner value supplied in the LOCK request
must be preserved by the server just like a dead property
(Section 14.17). Also added the DAV:lockroot element
(Section 14.12) which allows clients to discover the root of lock.
F.2. Changes for Server Implementations
Collections and Namespace Operations
o Due to interoperability problems, allowable formats for contents
of 'href' elements in multistatus responses have been limited (see
Section 8.3).
o Due to lack of implementation, support for the 'propertybehaviour'
request body for COPY and MOVE has been removed. Instead,
requirements for property preservation have been clarified (see
Sections 9.8 and 9.9).
Properties
o Strengthened server requirements for storage of property values,
in particular persistence of language information (xml:lang),
whitespace, and XML namespace information (see Section 4.3).
o Clarified requirements on which properties should be writeable by
the client; in particular, setting "DAV:displayname" should be
supported by servers (see Section 15).
o Only 'rfc1123-date' productions are legal as values for DAV:
getlastmodified (see Section 15.7).
Headers and Marshalling
o Servers are now required to do authorization checks before
processing conditional headers (see Section 8.5).
Locking
o Strengthened requirement to check identity of lock creator when
accessing locked resources (see Section 6.4). Clients should be
aware that lock tokens returned to other principals can only be
used to break a lock, if at all.
o Section 8.10.4 of [RFC2518] incorrectly required servers to return
a 409 status where a 207 status was really appropriate. This has
been corrected (Section 9.10).
F.3. Other Changes
The definition of collection state has been fixed so it doesn't vary
anymore depending on the Request-URI (see Section 5.2).
The DAV:source property introduced in Section 4.6 of [RFC2518] was
removed due to lack of implementation experience.
The DAV header now allows non-IETF extensions through URIs in
addition to compliance class tokens. It also can now be used in
requests, although this specification does not define any associated
semantics for the compliance classes defined in here (see
Section 10.1).
In RFC2518, the definition of the Depth header (Section 9.2) required
that by default request headers would be applied to each resource in
scope. Based on implementation experience, the default has now been
reversed (see Section 10.2).
The definitions of HTTP status code 102 ([RFC2518], Section 10.1) and
the Status-URI response header (Section 9.7) have been removed due to
lack of implementation.
The TimeType format used in the Timeout request header and the
"timeout" XML element used to be extensible. Now, only the two
formats defined by this specification are allowed (see Section 10.7).
Appendix G. Change Log (to be removed by RFC Editor before publication)
G.1. Changes from -05 to -06
Specified that a successful LOCK request to an unmapped URL creates a
new, empty locked resource.
Resolved UNLOCK_NEEDS_IF_HEADER by clarifying that only Lock-Token
header is needed on UNLOCK.
Added Section 16 on preconditions and postconditions and defined a
number of preconditions and postconditions. The 'lock-token-
submitted' precondition resolves the REPORT_OTHER_RESOURCE_LOCKED
issue.
Added example of matching lock token to URI in the case of a
collection lock in the If header section.
Removed ability for Destination header to take "abs_path" in order to
keep consistent with other places where client provides URLs (If
header, href element in request body)
Clarified the href element - that it generally contains HTTP URIs but
not always.
Attempted to fix the BNF describing the If header to allow commas
Clarified presence of Depth header on LOCK refresh requests.
G.2. Changes in -07
Added text to "COPY and the Overwrite Header" section to resolve
issue OVERWRITE_DELETE_ALL_TOO_STRONG.
Added text to "HTTP URL Namespace Model" section to provide more
clarification and examples on what consistency means and what is not
required, to resolve issue CONSISTENCY.
Resolve DEFINE_PRINCIPAL by importing definition of principal from
RFC3744.
Resolve INTEROP_DELETE_AND_MULTISTATUS by adding appendix 3
discussing backward-compatibility concerns.
Resolve DATE_FORMAT_GETLASTMODIFIED by allowing only rfc1123-date,
not HTTP-date for getlastmodified.
Resolve COPY_INTO_YOURSELF_CLARIFY by adding sentence to first para.
of COPY section.
Confirm that WHEN_TO_MULTISTATUS_FOR_DELETE_1 and
WHEN_TO_MULTISTATUS_FOR_DELETE_2 are resolved and tweak language in
DELETE section slightly to be clearly consistent.
More text clarifications to deal with several of the issues in
LOCK_ISSUES. This may not completely resolve that set but we need
feedback from the originator of the issues at this point.
Resolved COPY_INTO_YOURSELF_CLARIFY with new sentence in Copy For
Collections section.
Double checked that LEVEL_OR_CLASS is resolved by using class, not
level.
Further work to resolve IF_AND_AUTH and LOCK_SEMANTICS, clarifying
text on using locks and being authenticated.
Added notes on use of 503 status response to resolve issue
PROPFIND_INFINITY
Removed section on other uses of Metadata (and associated references)
Added reference to RFC4122 for lock tokens and removed section on
generating UUIDs
Explained that even with language variation, a property has only one
value (Section 4.5).
Added section on lock owner (7.1) and what to do if lock requested by
unauthenticated user
Removed Section 4.2 -- justification on why to have metadata, not
needed now
Removed paragraph in Section 5.2 about collections with resource type
"DAV:collection" but which are non-WebDAV compliant -- not
implemented.
G.3. Changes in -08
Added security considerations section on scripts and cookie sessions,
suggested by Barry Lind
Clarified which error codes are defined and undefined in MultiStatus
Moved opaquelocktoken definition to an appendix and refer to RFC4122
for use of 'urn:uuid:' URI scheme; fix all lock token examples to use
this.
Multi-status responses contain URLs which MUST either be absolute
(and begin with the Request-URI or MUST be relative with new
limitations. (bug 12)
Moved status code sections before example sections within PROPFIND
section for section ordering consistency.
Clarified use of Location header with Multi-Status
Bugzilla issue resolutions: bugs 9, 12, 14, 19, 20, 29, 30, 34, 36,
102 and 172.
G.4. Changes in -09
Bugzilla editorial issues: bugs 30, 57, 63, 68, 88, 89, 168, 180,
182, 185, 187.
More clarity between URL namespaces and XML namespaces, particularly
at the beginning of paragraphs using the word namespace
More consistency in referring to properties with the namespace, as in
"DAV:lockdiscovery", and referring to XML element names in single
quotes, e.g. 'allprop' element.
Figure (example) formatting fixes
Bugzilla issues: bugs 24, 37, 39, 43, 45, 27, 25
Replaced references to "non-null state" of resources with more clear
language about URLs that are mapped to resources, bug 25. Also added
definition of URL/URI mapping. Bug 40.
Bugzilla issues: bug 7, 8, 9, 41, 47, 51, 62, 93, 171, 172. Bugs 28
and 94 were iterated on.
Bugzilla issues: 56, 59, 79, 99, 103, 175, 178. Part of bug 23.
Iteration on bug 10.
Iteration on bugs 10, 46 and 47. Bug 11.
Remove "102 Processing" response
Fix bug 46, 105, 107, 120, 140 and 201.
Another stab at bug 12 - relative v. absolute URLs in Multi-Status
response hrefs
Fix bug 6, 11, 15, 16, 28, 32, 42, 51, 52, 53, 58, 60, 62, 186, 189,
191, 199, 200
Fix bug 96
G.5. Changes in -10
Clarify lock intro text on when a client might use another client's
lock token - suggestion by Geoff, Nov 15
Removed Force-Authenticate header and instead added an appendix
explaining how existing mechanisms might resolve the need of clients
to get an authentication challenge (bug 18).
Bug 62, 113, 125, 131, 143, 144, 171, 193
Bug 176, 177, 179, 181, 184, 206, 207, 208
G.6. Changes in -11
Bug 10, 50, 92, 213, 214, 215
not recommend use of 414 for over-long Destination URI, bug 179
Changes for bug 10, 31, 42, 44, 46, 47, 80, 86, 99, 124, 132, 143,
147, 152, 166, 177, 188, 216, 218
Various changes discussed in conference call, including bug 10, 42,
44, 80, 97, 152.
Bugs 55, 85, 86
G.7. Changes in -12
Incorporated GULP (Lock model) into document, making a fair number of
changes to rationalize the new order of explaining things, keeping
text that explains a lock model concept in more detail but removing
text that is redundant or inconsistent.
Various bugs including 46, 48, 53, 97, 152, 179, 184, 188, 200, 210,
211, and 225. Moved URL Handling from Multi-Status section to
general request and response handling section as it now applies to
Destination and If as well as 'href' in Multi-Status. Moved GR&RH
section up one level to be the new Section 8.
Bug 53, 184, 210, 213, 217, 221
Further rewriting of URL Handling section. Changes resulting from
discussion of empty locked resources and how servers should handle
Content-Type in that situation. Bug 48, 179.
Bug 227, 228
G.8. Changes in -13
Moved the timeout model text and clarified it (bug 229).
Fixed the definition of collection state (bug 227).
Made the depth header required on PROPFIND requests (bug 213).
Fixed inconsistencies in Destination header definition (bug 211).
Improved appendix on HTTP client compatibility (bug 100).
Fixed external references with unwieldy pointers (bug 72).
G.9. Changes in -14
Changes section rewritten, if section rewritten
Collection definition and membership requirements changed (bug 227)
Bug 100 and 229 iterations, smallish editorial changes
G.10. Changes in -15
Moved lock-null resource explanation to an appendix.
Reverted to RFC2518 behavior of refreshing lock with "If" header.
Removed section on locks and multiple bindings.
Removed requirement for clients to upate a property only once in a
PROPPATCH.
Updated displayname property description.
Copy-edit level changes e.g. "read-only" to "protected", and defining
what it means to protect a resource with a lock.
G.11. Changes in -16
Fixed factual errors in Security Considerations authentication
section.
Fixed example of refreshing a lock -- didn't use "If" header as
required in the text.
Fixed example of using so-called 'all-prop' with the 'include'
directivenotifi, so that it would actually be a useful example, by
including live properties that wouldn't already be covered by 'all-
prop'.
Clarified requirement in section 7.7 paragraph 2 -- a clear
requirement for the server to meet, rather than passive voice "this
request MUST only be used".
Made explicit requirement for successful response format for
PROPPATCH (bug 238)
Some fixes for bugs 213, 241, 246, 248, 249, 250 -- all editorial
changes.
Tighten requirements in Security Considerations section for
authentication over secure channels.
G.12. Changes in -17
Change reference for PROPFIND MultiStatus response format from
section 15 to section 9.2.1
Add another "except" clause to statement requiring pre/postcondition
codes to appear in 'error'
Remove requirement to use TLS -- back to requiring channel to be
secure.
G.13. Changes in -18
Text clarifications and typo fixes in response to IETF Last Call
comments
Removed suggestive/confusing text about lock notifications
Add section with guidance for clients dealing with both lock-null
resources and locked empty resources.
Allow servers to omit owner information in lockdiscovery property.
Clarify what 'allprop' means, mostly fixing misleading text in change
summary
Author's Address
Lisa Dusseault (editor)
CommerceNet
2064 Edgewood Dr.
Palo Alto, CA 94303
US
Email: ldusseault@commerce.net
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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