mirror of
https://github.com/moparisthebest/xeps
synced 2024-12-17 21:32:35 -05:00
219 lines
9.1 KiB
XML
219 lines
9.1 KiB
XML
<?xml version='1.0' encoding='UTF-8'?>
|
|
<!DOCTYPE xep SYSTEM 'xep.dtd' [
|
|
<!ENTITY % ents SYSTEM 'xep.ent'>
|
|
%ents;
|
|
]>
|
|
<?xml-stylesheet type='text/xsl' href='xep.xsl'?>
|
|
<xep>
|
|
<header>
|
|
<title>Pubsub Subscription Storage</title>
|
|
<abstract>This document defines an XMPP protocol extension for storing subscriptions to Pubsub nodes.</abstract>
|
|
&LEGALNOTICE;
|
|
<number>0173</number>
|
|
<status>Deferred</status>
|
|
<type>Historical</type>
|
|
<sig>Standards</sig>
|
|
<approver>Council</approver>
|
|
<dependencies>
|
|
<spec>XMPP Core</spec>
|
|
<spec>XEP-0049</spec>
|
|
<spec>XEP-0060</spec>
|
|
</dependencies>
|
|
<supersedes/>
|
|
<supersededby/>
|
|
<shortname>pubsubs</shortname>
|
|
<author>
|
|
<firstname>Magnus</firstname>
|
|
<surname>Henoch</surname>
|
|
<email>henoch@dtek.chalmers.se</email>
|
|
<jid>legoscia@jabber.cd.chalmers.se</jid>
|
|
</author>
|
|
<revision>
|
|
<version>0.1</version>
|
|
<date>2006-02-09</date>
|
|
<initials>psa</initials>
|
|
<remark><p>Initial version; changed title to Pubsub Subscription Storage; changed namespace to storage:pubsubs for consistency with other storage XEPs.</p></remark>
|
|
</revision>
|
|
<revision>
|
|
<version>0.0.4</version>
|
|
<date>2005-12-11</date>
|
|
<initials>mh</initials>
|
|
<remark><p>Add resource attribute.</p></remark>
|
|
</revision>
|
|
<revision>
|
|
<version>0.0.3</version>
|
|
<date>2005-11-13</date>
|
|
<initials>mh</initials>
|
|
<remark><p>Add subscription attribute.</p></remark>
|
|
</revision>
|
|
<revision>
|
|
<version>0.0.2</version>
|
|
<date>2005-10-28</date>
|
|
<initials>mh</initials>
|
|
<remark><p>Fix typo and schema.</p></remark>
|
|
</revision>
|
|
<revision>
|
|
<version>0.0.1</version>
|
|
<date>2005-10-25</date>
|
|
<initials>mh</initials>
|
|
<remark><p>First draft.</p></remark>
|
|
</revision>
|
|
</header>
|
|
<section1 topic='Introduction' anchor='intro'>
|
|
<p>&xep0060; allows Jabber entities to subscribe to various kinds of information, but provides no way of remembering which nodes a user has subscribed to. Other protocols (e.g. &xep0080;, &xep0084;) allow information about a certain entity to be published to a Pubsub node. These protocols use &xep0030; to allow other entities to find the pubsub node used by a certain entity, but provide no way of performing the opposite mapping, from pubsub node to information source. This document attempts to fill that void, using &xep0049; for storing information about subscriptions.</p>
|
|
</section1>
|
|
<section1 topic='Requirements' anchor='reqs'>
|
|
<p>This protocol enables Jabber clients to do the following:</p>
|
|
<ul>
|
|
<li>Remember which pubsub nodes the entity has subscribed to, and what kind of information is available at each node</li>
|
|
<li>Update the mappings when subscriptions are added or removed</li>
|
|
<li>Correlate incoming pubsub events to subscriptions</li>
|
|
</ul>
|
|
</section1>
|
|
<section1 topic='Protocol' anchor='proto'>
|
|
<p>The <subscriptions/> element qualified by the 'storage:pubsubs' namespace is the root element used in the jabber:iq:private transactions. It has zero or more <subscription/> child elements, each of which MUST possess the following attributes:</p>
|
|
|
|
<ul>
|
|
<li><em>jid</em> -- The JID of the pubsub service used</li>
|
|
<li><em>node</em> -- The pubsub node at which the data is available</li>
|
|
<li><em>subscription</em> -- The current subscription state, one of "none", "pending", "unconfigured" and "subscribed"</li>
|
|
</ul>
|
|
|
|
<p>Additionally, the <subscription/> element MAY possess these attributes:</p>
|
|
<ul>
|
|
<li><em>resource</em> -- The resource that is subscribed to this pubsub node. If the 'resource' attribute is absent, the bare JID is subscribed.</li>
|
|
<li><em>user</em> -- The JID of the owner of this particular piece of data</li>
|
|
<li><em>targetns</em> -- The namespace of the data in question</li>
|
|
</ul>
|
|
</section1>
|
|
<section1 topic='Use Cases' anchor='usecases'>
|
|
<section2 topic='Retrieving Existing Subscriptions' anchor='retrieving'>
|
|
<p>In this example, the user already has a subscription to Juliet's geolocation, possibly established through another client.</p>
|
|
<example caption='Client requests existing subscriptions'><![CDATA[
|
|
<iq type='get' id='retrieve1'>
|
|
<query xmlns='jabber:iq:private'>
|
|
<subscriptions xmlns='storage:pubsubs'/>
|
|
</query>
|
|
</iq>
|
|
]]></example>
|
|
<example caption='Server returns existing subscriptions'><![CDATA[
|
|
<iq type='result' id='retrieve1'>
|
|
<query xmlns='jabber:iq:private'>
|
|
<subscriptions xmlns='storage:pubsubs'>
|
|
<subscription user='juliet@capulet.com'
|
|
jid='pubsub.capulet.com'
|
|
node='juliet/geoloc'
|
|
targetns='http://jabber.org/protocol/geoloc'
|
|
subscription='subscribed'/>
|
|
</subscriptions>
|
|
</query>
|
|
</iq>
|
|
]]></example>
|
|
</section2>
|
|
|
|
<section2 topic='Updating Subscriptions' anchor='updating'>
|
|
<p>Due to the nature of XEP-0049, incremental updates are not possible; a client MUST send the entire <subscriptions/> node for each update. Before performing the update, the client SHOULD retrieve the stored subscriptions, and incorporate any changes.</p>
|
|
<p>In this example, the user has just subscribed to Romeo's tune (see &xep0118;). Assuming that retrieving happened as in the previous use case, updating the subscriptions proceeds as follows:</p>
|
|
<example caption='Client sends updated subscriptions'><![CDATA[
|
|
<iq type='set' id='update1'>
|
|
<query xmlns='jabber:iq:private'>
|
|
<subscriptions xmlns='storage:pubsubs'>
|
|
<subscription user='juliet@capulet.com'
|
|
jid='pubsub.capulet.com'
|
|
node='juliet/geoloc'
|
|
targetns='http://jabber.org/protocol/geoloc'
|
|
subscription='subscribed'/>
|
|
<subscription user='romeo@montague.net'
|
|
jid='pubsub.montague.net'
|
|
node='5017cdc9f4a3d1450445c9096064e459'
|
|
targetns='http://jabber.org/protocol/tune'
|
|
subscription='subscribed'/>
|
|
</subscriptions>
|
|
</query>
|
|
</iq>
|
|
]]></example>
|
|
<example caption='Server reports success'><![CDATA[
|
|
<iq type='result' id='update1'/>
|
|
]]></example>
|
|
</section2>
|
|
|
|
<section2 topic='Identifying Incoming Events' anchor='identifying'>
|
|
<p>Having recorded the retrieved mappings, the client is now prepared to identify incoming pubsub events. Assume that the following event arrives:</p>
|
|
<example caption='Client receives pubsub event'><![CDATA[
|
|
<message
|
|
from='pubsub.montague.net'
|
|
to='mercutio@shakespeare.lit'>
|
|
<event xmlns='http://jabber.org/protocol/pubsub#event'>
|
|
<items node='5017cdc9f4a3d1450445c9096064e459'>
|
|
<item id='current'>
|
|
<tune xmlns='http://jabber.org/protocol/tune'>
|
|
<artist>Yes</artist>
|
|
<title>Heart of the Sunrise</title>
|
|
<source>Yessongs</source>
|
|
<track>3</track>
|
|
<length>686</length>
|
|
</tune>
|
|
</item>
|
|
</items>
|
|
</event>
|
|
</message>
|
|
]]></example>
|
|
<p>The client now knows that this information comes from romeo@montague.net.</p>
|
|
</section2>
|
|
</section1>
|
|
<section1 topic='Security Considerations' anchor='security'>
|
|
<p>Pubsub events offer an opportunity to spoof sender addresses e.g. through 'replyto' data (as specified by the &xep0033; protocol). This protocol attempts to close that hole. It does so by the following rules and assumptions:</p>
|
|
<ul>
|
|
<li>A client MUST add mappings (i.e. associations between a publisher's JID and a pubsub node) only from trustworthy sources, i.e. published disco items (see &xep0030;). This relies on disco information not being cracked or falsified.</li>
|
|
<li>A client MUST retrieve mappings only from trustworthy sources, i.e. private XML storage. This assumes that no-one but the user is able to change such information.</li>
|
|
</ul>
|
|
</section1>
|
|
<section1 topic='IANA Considerations' anchor='iana'>
|
|
<p>This document requires no interaction with &IANA;.</p>
|
|
</section1>
|
|
<section1 topic='XMPP Registrar Considerations' anchor='registrar'>
|
|
<p>No namespaces or parameters need to be registered with the ®ISTRAR; as a result of this document.</p>
|
|
</section1>
|
|
<section1 topic='XML Schema' anchor='schema'>
|
|
<code><![CDATA[
|
|
<?xml version='1.0' encoding='UTF-8'?>
|
|
|
|
<xs:schema
|
|
xmlns:xs='http://www.w3.org/2001/XMLSchema'
|
|
targetNamespace='storage:pubsubs'
|
|
xmlns='storage:pubsubs'
|
|
elementFormDefault='qualified'>
|
|
|
|
<xs:element name='subscriptions'>
|
|
<xs:complexType>
|
|
<xs:sequence>
|
|
<xs:element ref='subscription' minOccurs='0' maxOccurs='unbounded'/>
|
|
</xs:sequence>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
|
|
<xs:element name='subscription'>
|
|
<xs:complexType>
|
|
<xs:attribute name='jid' type='xs:string' use='required'/>
|
|
<xs:attribute name='node' type='xs:string' use='required'/>
|
|
<xs:attribute name='subscription' use='required'>
|
|
<xs:simpleType>
|
|
<xs:restriction base='xs:NCName'>
|
|
<xs:enumeration value='none'/>
|
|
<xs:enumeration value='pending'/>
|
|
<xs:enumeration value='subscribed'/>
|
|
<xs:enumeration value='unconfigured'/>
|
|
</xs:restriction>
|
|
</xs:simpleType>
|
|
</xs:attribute>
|
|
<xs:attribute name='resource' type='xs:string' use='optional'/>
|
|
<xs:attribute name='user' type='xs:string' use='optional'/>
|
|
<xs:attribute name='targetns' type='xs:string' use='optional'/>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
|
|
</xs:schema>
|
|
]]></code>
|
|
</section1>
|
|
</xep>
|