XEP-0182: Application-Specific Error Conditions

Abstract:This document defines a registry of application-specific error conditions.
Author:Peter Saint-Andre
Copyright:© 1999 - 2014 XMPP Standards Foundation. SEE LEGAL NOTICES.
Status:Active
Type:Procedural
Version:1.1
Last Updated:2008-03-05

NOTICE: This Procedural document defines a process or activity of the XMPP Standards Foundation (XSF) that has been approved by the XMPP Council and/or the XSF Board of Directors. The XSF is currently following the process or activity defined herein and will do so until this document is deprecated or obsoleted.


Table of Contents


1. Introduction
2. XMPP Registrar Considerations
    2.1. Application-Specific Error Conditions Registry
       2.1.1. Registration Process
    2.2. Protocol Namespaces
3. Security Considerations
4. IANA Considerations

Appendices
    A: Document Information
    B: Author Information
    C: Legal Notices
    D: Relation to XMPP
    E: Discussion Venue
    F: Requirements Conformance
    G: Notes
    H: Revision History


1. Introduction

XMPP Core [1] specifies that an XMPP error stanza may include a child element qualified by an XML namespace other than 'urn:ietf:params:xml:ns:xmpp-stanzas'. This enables any XMPP protocol extension to define its own application-specific error conditions, such as the following:

Example 1. An Application-Specific Error Condition (invalid-jid)

<iq type='error' from='pubsub.shakespeare.lit' to='francisco@denmark.lit/barracks' id='sub1'>
  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
    <subscribe node='blogs/princely_musings' jid='bernardo@denmark.lit'/>
  </pubsub>
  <error type='modify'>
    <bad-request xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
    <invalid-jid xmlns='http://jabber.org/protocol/pubsub#errors'/>
  </error>
</iq>
  

Although the inclusion of application-specific error conditions introduces a great deal of flexibility, it may also lead to confusion regarding possible conditions. Therefore, this document defines a registry of application-specific error conditions, to be maintained by the XMPP Registrar [2]. In addition, this document registers a namespace of 'urn:xmpp:errors' as a fallback namespace for generalized error conditions that are not specific to a particular protocol (e.g., <stanza-too-big/> as a particular form of the <not-acceptable/> condition).

2. XMPP Registrar Considerations

2.1 Application-Specific Error Conditions Registry

The XMPP Registrar maintains a registry of application-specific error conditions (see <http://xmpp.org/registrar/errors.html>).

All application-specific error conditions that are defined in XMPP Extension Protocol specifications MUST be included in this registry. Application-specific error conditions that are defined outside of the XMPP Standards Foundation's standards process (see XMPP Extension Protocols (XEP-0001) [3]) MAY be included in this registry, but it is not required for them to be so registered.

2.1.1 Registration Process

In order to submit new values to this registry, the registrant shall define an XML fragment of the following form and either include it in the relevant XMPP Extension Protocol or send it to the email address <registrar@xmpp.org>:

<condition>
  <ns>the XML namespace that qualifies the condition</ns>
  <element>the XML element of the error condition</element>
  <desc>a natural-language description of the error condition</desc>
  <doc>the document in which the condition is specified</doc>
</condition>
      

The registrant may register more than one condition at a time, each contained in a separate <condition/> element.

2.2 Protocol Namespaces

The XMPP Registrar [4] includes 'urn:xmpp:errors' in its registry of protocol namespaces.

3. Security Considerations

This document introduces no known security vulnerabilities.

4. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [5].


Appendices


Appendix A: Document Information

Series: XEP
Number: 0182
Publisher: XMPP Standards Foundation
Status: Active
Type: Procedural
Version: 1.1
Last Updated: 2008-03-05
Approving Body: XMPP Council
Dependencies: XMPP Core
Supersedes: None
Superseded By: None
Short Name: errors
Registry: <http://xmpp.org/registrar/errors.html>
Source Control: HTML
This document in other formats: XML  PDF


Appendix B: Author Information

Peter Saint-Andre

Email: stpeter@jabber.org
JabberID: stpeter@jabber.org
URI: https://stpeter.im/


Appendix C: Legal Notices

Copyright

This XMPP Extension Protocol is copyright © 1999 - 2014 by the XMPP Standards Foundation (XSF).

Permissions

Permission is hereby granted, free of charge, to any person obtaining a copy of this specification (the "Specification"), to make use of the Specification without restriction, including without limitation the rights to implement the Specification in a software program, deploy the Specification in a network service, and copy, modify, merge, publish, translate, distribute, sublicense, or sell copies of the Specification, and to permit persons to whom the Specification is furnished to do so, subject to the condition that the foregoing copyright notice and this permission notice shall be included in all copies or substantial portions of the Specification. Unless separate permission is granted, modified works that are redistributed shall not contain misleading information regarding the authors, title, number, or publisher of the Specification, and shall not claim endorsement of the modified works by the authors, any organization or project to which the authors belong, or the XMPP Standards Foundation.

Disclaimer of Warranty

## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##

Limitation of Liability

In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall the XMPP Standards Foundation or any author of this Specification be liable for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if the XMPP Standards Foundation or such author has been advised of the possibility of such damages.

IPR Conformance

This XMPP Extension Protocol has been contributed in full conformance with the XSF's Intellectual Property Rights Policy (a copy of which can be found at <http://xmpp.org/about-xmpp/xsf/xsf-ipr-policy/> or obtained by writing to XMPP Standards Foundation, 1899 Wynkoop Street, Suite 600, Denver, CO 80202 USA).

Appendix D: Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 6120) and XMPP IM (RFC 6121) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.


Appendix E: Discussion Venue

The primary venue for discussion of XMPP Extension Protocols is the <standards@xmpp.org> discussion list.

Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.

Errata can be sent to <editor@xmpp.org>.


Appendix F: Requirements Conformance

The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".


Appendix G: Notes

1. RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core <http://tools.ietf.org/html/rfc6120>.

2. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://xmpp.org/registrar/>.

3. XEP-0001: XMPP Extension Protocols <http://xmpp.org/extensions/xep-0001.html>.

4. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://xmpp.org/registrar/>.

5. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.


Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

Version 1.1 (2008-03-05)

Changed namespace from http://jabber.org/protocol/errors to urn:xmpp:errors.

(psa)

Version 1.0 (2006-05-16)

Per a vote of the Jabber Council, advanced status to Active; also added example.

(psa)

Version 0.2 (2006-04-28)

Added note about scope of registry.

(psa)

Version 0.1 (2006-03-23)

Initial version.

(psa)

Version 0.0.1 (2006-03-21)

First draft.

(psa)

END