XEP-xxxx: File Transfer Metadata

Abstract:An extension to XEP-0096 and XEP-0234 to design a way of adding arbitrary data to file transfer offers.
Author:Jonny Lamb
Copyright:© 1999 - 2011 XMPP Standards Foundation. SEE LEGAL NOTICES.
Status:ProtoXEP
Type:Standards Track
Version:0.0.1
Last Updated:2011-11-11

WARNING: This document has not yet been accepted for consideration or approved in any official manner by the XMPP Standards Foundation, and this document is not yet an XMPP Extension Protocol (XEP). If this document is accepted as a XEP by the XMPP Council, it will be published at <http://xmpp.org/extensions/> and announced on the <standards@xmpp.org> mailing list.


Table of Contents


1. Introduction
2. Requirements
3. Use Case
4. Examples
5. Security Considerations
6. IANA Considerations
7. XMPP Registrar 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

The current methods for file transfers include basic metadata about the file being offered such as its name, size, and date. There currently is no way to provide arbitrary details about the file being transferred. XEP-0264 starts to address this problem, but only includes thumbnails of transfers.

The design of this extension to file transfer offers is influenced by adding data forms to disco#info replies (as per Entity Capabilities [1]) and by the design of File Transfer Thumbnails [2]

2. Requirements

This document defines a way to include arbitrary data in a file transfer.

3. Use Case

The arbitrary data added to the offer is incluced in Data Forms [3] which must be formatted according to Service Discovery Extensions [4] to the root <file> element. There can be as many data forms under said <file> element as long as the FORM_TYPE field is different for each form.

4. Examples

Example 1. Inclusion of photo EXIF data in an SI file transfer offer

<iq type='set' id='offer1' to='receiver@jabber.org/resource'>
  <si xmlns='http://jabber.org/protocol/si'
      id='a0'
      mime-type='image/jpeg'
      profile='http://jabber.org/protocol/si/profile/file-transfer'>
    <file xmlns='http://jabber.org/protocol/si/profile/file-transfer'
          name='thatwildparty.jpg'
          size='3240688'>
      <x xmlns='jabber:x:data' type='result'>
        <field var='FORM_TYPE' type='hidden'>
          <value>example:dataform:exifdata</value>
        </field>
        <field var='ImageWidth'>
          <value>3872</value>
        </field>
        <field var='ImageHeight'>
          <value>2592</value>
        </field>
        <field var='Make'>
          <value>NIKON CORPORATION</value>
        </field>
        <field var='Model'>
          <value>NIKON D80</value>
        </field>
      </x>
    </file>
    ...
  </si>
</iq>

Example 2. Inclusion of photo EXIF data in a Jingle file transfer offer

<iq from='romeo@montague.lit/orchard'
    id='nzu25s8'
    to='juliet@capulet.lit/balcony'
    type='set'>
  <jingle xmlns='urn:xmpp:jingle:1'
          action='session-initiate'
          initiator='romeo@montague.lit/orchard'
          sid='851ba2'>
    <content creator='initiator' name='a-file-offer'>
      <description xmlns='urn:xmpp:jingle:apps:file-transfer:3'>
        <offer>
          <file>
            <date>1969-07-21T02:56:15Z</date>
            <desc>The wild party you should've been at</desc>
            <name>thatwildparty.jpg</name>
            <range/>
            <size>8492843</size>
            <hashes xmlns='urn:xmpp:hashes:0'>
              <hash algo='sha1'>552da749930852c69ae5d2141d3766b1</hash>
            </hashes>
            <x xmlns='jabber:x:data' type='result'>
              <field var='FORM_TYPE' type='hidden'>
                <value>example:dataform:exifdata</value>
              </field>
              <field var='ImageWidth'>
                <value>3872</value>
              </field>
              <field var='ImageHeight'>
                <value>2592</value>
              </field>
              <field var='Make'>
                <value>NIKON CORPORATION</value>
              </field>
              <field var='Model'>
                <value>NIKON D80</value>
              </field>
            </x>
          </file>
        </offer>
      </description>
      ...
    </content>
  </jingle>
</iq>

5. Security Considerations

This document introduces no security concerns above and beyond those specified in Data Forms [5].

6. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [6].

7. XMPP Registrar Considerations

This document requires no interaction with the XMPP Registrar [7]; however, specifications following the best practices defined herein may register FORM_TYPEs and field values with the XMPP Registrar.


Appendices


Appendix A: Document Information

Series: XEP
Number: xxxx
Publisher: XMPP Standards Foundation
Status: ProtoXEP
Type: Standards Track
Version: 0.0.1
Last Updated: 2011-11-11
Approving Body: XMPP Council
Dependencies: XMPP Core, XEP-0096, XEP-0234
Supersedes: None
Superseded By: None
Short Name: NOT YET ASSIGNED
This document in other formats: XML  PDF


Appendix B: Author Information

Jonny Lamb

Email: jonny.lamb@collabora.co.uk
JabberID: jonny.lamb@collabora.co.uk


Appendix C: Legal Notices

Copyright

This XMPP Extension Protocol is copyright © 1999 - 2011 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 3920) and XMPP IM (RFC 3921) 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. XEP-0115: Entity Capabilities <http://xmpp.org/extensions/xep-0115.html>.

2. XEP-0264: File Transfer Thumbnails <http://xmpp.org/extensions/xep-0264.html>.

3. XEP-0004: Data Forms <http://xmpp.org/extensions/xep-0004.html>.

4. XEP-0128: Service Discovery Extensions <http://xmpp.org/extensions/xep-0128.html>.

5. XEP-0004: Data Forms <http://xmpp.org/extensions/xep-0004.html>.

6. 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/>.

7. 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/>.


Appendix H: Revision History

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

Version 0.0.1 (2011-11-11)

Initial version. (jl)

END