mirror of
https://github.com/moparisthebest/xeps
synced 2024-10-31 15:35:07 -04:00
81e955126b
git-svn-id: file:///home/ksmith/gitmigration/svn/xmpp/trunk@2677 4b5297f7-1745-476d-ba37-a9c6900126ab
467 lines
18 KiB
XML
467 lines
18 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>Message Mine-ing</title>
|
|
<abstract>In servers that deliver messages intended for the bare JID to
|
|
all resources, the resource that claims a conversation notifies all
|
|
of the other resources of that claim.</abstract>
|
|
&LEGALNOTICE;
|
|
<number>0259</number>
|
|
<status>Experimental</status>
|
|
<type>Standards Track</type>
|
|
<sig>Standards</sig>
|
|
<approver>Council</approver>
|
|
<dependencies>
|
|
<spec>XMPP Core</spec>
|
|
<spec>XEP-0030</spec>
|
|
<spec>XEP-0045</spec>
|
|
<spec>XEP-0115</spec>
|
|
</dependencies>
|
|
<supersedes/>
|
|
<supersededby/>
|
|
<shortname>mine</shortname>
|
|
&hildjj;
|
|
<revision>
|
|
<version>0.1</version>
|
|
<date>2009-01-21</date>
|
|
<initials>psa</initials>
|
|
<remark><p>Initial published version.</p></remark>
|
|
</revision>
|
|
<revision>
|
|
<version>0.0.1</version>
|
|
<date>2008-10-22</date>
|
|
<initials>jjh</initials>
|
|
<remark><p>First draft.</p></remark>
|
|
</revision>
|
|
</header>
|
|
<section1 topic='Introduction' anchor='intro'>
|
|
<p>At the time of original writing of this XEP, many XMPP servers
|
|
handle message stanzas sent to a user@host (or "bare") JID with no
|
|
resource by delivering that message only to the resource with
|
|
the highest priority for the target user. Some server
|
|
implementations, however, have chosen to send these messages to all
|
|
of the online resources for the target user. If the target user is
|
|
online with multiple resources when the orginal message is sent, a
|
|
conversation ensues on one of the user's devices; if the user
|
|
subsequently switches devices, parts of the conversation may end up
|
|
on the alternate device, causing the user to be confused, misled,
|
|
or annoyed.</p>
|
|
|
|
<p>This XEP proposes an approach for cleaning up the leftover
|
|
conversation shards on alternate devices, paving the way for servers
|
|
to deliver messages to multiple devices. As the basic approach, the
|
|
receiving server asks all of the resources of a user "whose message
|
|
is this?". The first resource to say "mine!" wins.</p>
|
|
</section1>
|
|
<section1 topic='Requirements' anchor='reqs'>
|
|
<ul>
|
|
<li>Large changes SHOULD NOT be required to existing servers</li>
|
|
<li>Clients that do not implement the new protocol MUST be able
|
|
participate in conversations</li>
|
|
<li>All messages MUST NOT be delivered to all devices at all
|
|
times, due to scale concerns</li>
|
|
<li>Clients that do not own the message MUST be notified
|
|
when a different device claims ownership of the message</li>
|
|
<li>Multiple clients MUST be able to uambiguosly decide which of
|
|
them owns a given message.</li>
|
|
</ul>
|
|
</section1>
|
|
<section1 topic='Use Cases' anchor='usecases'>
|
|
<section2 topic='Determining Support: Servers' anchor='disco_server'>
|
|
<p>If a server implements the Mine capability, it MUST specify the
|
|
'urn:xmpp:tmp:mine:0' feature in its service discovery
|
|
information features as specified in &xep0115; or &xep0030;.
|
|
Clients MUST NOT send ownership changes if their server does
|
|
not support this feature.</p>
|
|
<example caption='Client requests information about its own server'><![CDATA[
|
|
<iq type='get'
|
|
from='romeo@montague.net/orchard'
|
|
id='info1'>
|
|
<query xmlns='http://jabber.org/protocol/disco#info'/>
|
|
</iq>]]></example>
|
|
<example caption='Server responds with mine feature'><![CDATA[
|
|
<iq type='get'
|
|
to='romeo@montague.net/home'
|
|
from='montague.net'
|
|
id='info1'>
|
|
<query xmlns='http://jabber.org/protocol/disco#info'>
|
|
...
|
|
<feature var='urn:xmpp:tmp:mine:0'/>
|
|
...
|
|
</query>
|
|
</iq>]]></example>
|
|
</section2>
|
|
<section2 topic='Determining Support: Clients' anchor='disco_client'>
|
|
<p>Clients that support this protocol MUST support <cite>XEP-0115</cite>, and MUST add the
|
|
'urn:xmpp:tmp:mine:0' feature to their entity capabilities, in
|
|
order to allow for potential server optimizations.</p>
|
|
<example caption='Romeo publishes his capabilities'><![CDATA[
|
|
<presence from='romeo@example.net/home'>
|
|
<c xmlns='http://jabber.org/protocol/caps'
|
|
hash='sha-1'
|
|
node='http://example.com/clients/Mine'
|
|
ver='j+5eLRCz6NP6IEPob80JB6sWR3Y='/>
|
|
</presence>
|
|
]]></example>
|
|
<example caption='Romeo responds to capabilities inquiry from his server'><![CDATA[
|
|
<iq from='romeo@example.net/home'
|
|
id='disco1'
|
|
to='example.net'
|
|
type='result'>
|
|
<query xmlns='http://jabber.org/protocol/disco#info'
|
|
node='http://example.com/clients/Mine#/WmLAKHhB87dOqn5NUgxrr5NbfE='>
|
|
<identity category='client' type='pc' name='Mine'/>
|
|
<feature var='urn:xmpp:tmp:mine:0'/>
|
|
</query>
|
|
</iq>]]></example>
|
|
</section2>
|
|
<section2 topic='Receving a message to the bare JID' anchor='receiving'>
|
|
<p>When a server that implements the Mine capability receives a
|
|
message addressed to a user's bare JID, it MUST:</p>
|
|
<ul>
|
|
<li>Ensure that no "whose" element is already on the message.
|
|
See the <link url="#errors">Errors</link> section for processing.</li>
|
|
<li>Add a whose element to the message, containing an id
|
|
attribute with a new value</li>
|
|
<li>Ensure that the the same value of the "id" attribute is
|
|
never sent to the same session </li>
|
|
</ul>
|
|
|
|
<p>Messages that have been processed to include a valid "whose"
|
|
element, are now also considered an "ownership request"</p>
|
|
|
|
<example caption='Juliet sends Romeo an undirected message'><![CDATA[
|
|
<message
|
|
from='juliet@example.com/balcony'
|
|
to='romeo@example.net'
|
|
type='chat'>
|
|
<body>Wherefore art thou, Romeo?</body>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
</message>
|
|
]]></example>
|
|
|
|
<example caption='The ownership request, before broadcasting'><![CDATA[
|
|
<message
|
|
from='juliet@example.com/balcony'
|
|
to='romeo@example.net'
|
|
type='chat'>
|
|
<body>Wherefore art thou, Romeo?</body>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='4'/>
|
|
</message>
|
|
]]></example>
|
|
</section2>
|
|
|
|
<section2 topic='Broadcasting ownership requests' anchor='broadcast'>
|
|
<p>The receiving server MUST send a copy of the ownership request
|
|
to each of that user's non-negative priority resources. Each copy
|
|
of the message MUST contain a whose element, each of which has the
|
|
same id attribute.</p>
|
|
<example caption='Romeo's server forwards copies of the
|
|
message to all of his resources'><![CDATA[
|
|
<message
|
|
from='juliet@example.com/balcony'
|
|
to='romeo@example.net/home'
|
|
type='chat'>
|
|
<body>Wherefore art thou, Romeo?</body>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='4'/>
|
|
</message>
|
|
|
|
<message
|
|
from='juliet@example.com/balcony'
|
|
to='romeo@example.net/work'
|
|
type='chat'>
|
|
<body>Wherefore art thou, Romeo?</body>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='4'/>
|
|
</message>
|
|
|
|
<message
|
|
from='juliet@example.com/balcony'
|
|
to='romeo@example.net/mobile'
|
|
type='chat'>
|
|
<body>Wherefore art thou, Romeo?</body>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='4'/>
|
|
</message>
|
|
]]></example>
|
|
</section2>
|
|
|
|
<section2 topic='Claiming ownership' anchor='claim'>
|
|
<p>When one client for a receiving user detects that the user's
|
|
attention has been directed to a given message, that client MUST
|
|
send an ownership claim (mine!) to the bare JID of the receiving
|
|
user. If there was a thread element in the original message, it
|
|
MUST be included in the acceptance notification. There MUST NOT
|
|
be a body element in the message, and the message SHOULD use the
|
|
same message type as the ownership request. The mine element MUST
|
|
include an id element for each of the messages that the client
|
|
wants to accept. The mine element MUST include at least one
|
|
id.</p>
|
|
<example caption='Romeo's "work" client claims ownership'><![CDATA[
|
|
<message
|
|
to='romeo@example.net'
|
|
from='romeo@example.net/work'
|
|
type='chat'>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<mine xmlns='urn:xmpp:tmp:mine:0'>
|
|
<id>4</id>
|
|
</mine>
|
|
</message>
|
|
]]></example>
|
|
</section2>
|
|
<section2 topic='Notification of ownership claim' anchor='notification'>
|
|
<p>As with all messages sent to a bare JID at a server
|
|
implementing the Mine feature, the acceptance message MUST be
|
|
forwarded to all of the non-negative priority resources.</p>
|
|
<example caption='Each of Romeo's clients receives the claim'><![CDATA[
|
|
<message
|
|
to='romeo@example.net/home'
|
|
from='romeo@example.net/work'
|
|
type='chat'>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<mine xmlns='urn:xmpp:tmp:mine:0'>
|
|
<id>4</id>
|
|
</mine>
|
|
</message>
|
|
|
|
<message
|
|
to='romeo@example.net/work'
|
|
from='romeo@example.net/work'
|
|
type='chat'>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<mine xmlns='urn:xmpp:tmp:mine:0'>
|
|
<id>4</id>
|
|
</mine>
|
|
</message>
|
|
|
|
<message
|
|
to='romeo@example.net/mobile'
|
|
from='romeo@example.net/work'
|
|
type='chat'>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<mine xmlns='urn:xmpp:tmp:mine:0'>
|
|
<id>4</id>
|
|
</mine>
|
|
</message>
|
|
]]></example>
|
|
</section2>
|
|
<section2 topic='Claim processing' anchor='processing'>
|
|
<p>When a client receives an ownership claim that was sent from
|
|
that client for an ID that has not been previously claimed,
|
|
the client MUST note that the message associated with the ID has
|
|
been confirmed, and ignore any further ownership claims for
|
|
that ID.</p>
|
|
<p>When a client receives an ownership claim that was sent from
|
|
a different client of the same user for a ID that has not
|
|
been previously received, the client MUST note that the message
|
|
associated with the ID has been retracted, and ignore any further
|
|
ownership claims for that ID. Retracted messages SHOULD
|
|
be removed from the client's user interface, or otherwise marked
|
|
in some way as retracted.</p>
|
|
<p>Clients MUST ignore ownership claims for IDs for which they
|
|
have no corresponding message.</p>
|
|
<p>Assuming that messages are delivered and processed in order,
|
|
these rules should ensure that exactly one client resource has a
|
|
confirmed copy of the message</p>
|
|
</section2>
|
|
<section2 topic='Claims for Multi-User Chat rooms' anchor='muc'>
|
|
<p>The same approach that has been described for one-to-one
|
|
messages above can also be used by &xep0045; (MUC) rooms.
|
|
Rooms that want to participate MUST send the
|
|
'urn:xmpp:tmp:mine:0' feature in the room's disco info. The room
|
|
MUST then perform the role of the server in the above
|
|
descriptions, ensuring that unique ID's are assigned to all
|
|
outbound groupchat messages that were addressed to the bare JID of
|
|
the room. Ownership claims MUST be sent to the bare JID of the
|
|
<strong>room</strong>, not the receiving user.</p>
|
|
<p>This capability might be used to distribute questions to
|
|
multiple experts in a room, such that a single expert answers a
|
|
question.</p>
|
|
<example caption='Message is sent to the room'><![CDATA[
|
|
<message
|
|
from='hag66@shakespeare.lit/pda'
|
|
to='darkcave@chat.shakespeare.lit'
|
|
type='groupchat'>
|
|
<body>Harpier cries: 'tis time, 'tis time.</body>
|
|
</message>]]></example>
|
|
<example caption='Room forwards message to all participants as ownership request'><![CDATA[
|
|
<message
|
|
from='darkcave@chat.shakespeare.lit/thirdwitch'
|
|
to='crone1@shakespeare.lit/desktop'
|
|
type='groupchat'>
|
|
<body>Harpier cries: 'tis time, 'tis time.</body>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='5'/>
|
|
</message>
|
|
|
|
<message
|
|
from='darkcave@chat.shakespeare.lit/thirdwitch'
|
|
to='wiccarocks@shakespeare.lit/laptop'
|
|
type='groupchat'>
|
|
<body>Harpier cries: 'tis time, 'tis time.</body>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='5'/>
|
|
</message>
|
|
|
|
<message
|
|
from='darkcave@chat.shakespeare.lit/thirdwitch'
|
|
to='hag66@shakespeare.lit/pda'
|
|
type='groupchat'>
|
|
<body>Harpier cries: 'tis time, 'tis time.</body>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='5'/>
|
|
</message>
|
|
]]></example>
|
|
<example caption='A participant claims ownership'><![CDATA[
|
|
<message
|
|
to='darkcave@chat.shakespeare.lit'
|
|
from='crone1@shakespeare.lit/desktop'
|
|
type='groupchat'>
|
|
<mine xmlns='urn:xmpp:tmp:mine:0'>
|
|
<id>5</id>
|
|
</mine>
|
|
</message>
|
|
]]></example>
|
|
</section2>
|
|
</section1>
|
|
|
|
<section1 topic='Error Cases' anchor='errors'>
|
|
<section2 topic='Invalid "whose"' anchor='bad_whose'>
|
|
<p>A server receives a message addressed to the bare JID of a
|
|
user, from a different user than the one in the to address,
|
|
containing a "whose" or "mine" element, it MUST NOT forward the
|
|
message on to any clients. This case is always either an attack,
|
|
a misconfiguration, or the result of bad code. If the user in the
|
|
from address is already known to the user in the to address (for
|
|
example, to user in the to address has a presence subscription to
|
|
the user in the from address), the server MAY send back a helpful
|
|
"bad-request" error.</p>
|
|
<example caption='Romeo responds to a bad request from his friend Juliet'><![CDATA[
|
|
<message
|
|
to='juliet@example.com/balcony'
|
|
from='romeo@example.net'
|
|
type='error>
|
|
<thread>0e3141cd80894871a68e6fe6b1ec56fa</thread>
|
|
<body>My client runneth over</body>
|
|
<whose xmlns='urn:xmpp:tmp:mine:0' id='4'>
|
|
<error type='modify'>
|
|
<bad-request xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
|
|
<text>Yours</text>
|
|
</error>
|
|
</message>
|
|
]]></example>
|
|
<p>However, if the user in the from address is not known to the user
|
|
in the to address, or the server perfers not to send helpful
|
|
errors, the server MUST treat the message as if it was addressed
|
|
to an unknown user. Otherwise, sending a message with an invalid
|
|
"whose" or "mine" could allow an attacker to probe for valid users
|
|
at a site.</p>
|
|
</section2>
|
|
</section1>
|
|
<section1 topic='Business Rules' anchor='rules'>
|
|
<section2 topic='Generating IDs' anchor='generate'>
|
|
<p>The value of the id attribute sent by servers MUST be
|
|
valid output from the NODEPREP profile of stringprep.</p>
|
|
</section2>
|
|
<section2 topic="ID Semantics" anchor="semantics">
|
|
<p>The value of the id resource is completely opqaque;
|
|
receiving clients MUST NOT use any apparent order or semantic in
|
|
the value of the id to perform optimizations or business
|
|
logic.</p>
|
|
</section2>
|
|
<section2 topic='Comparing IDs' anchor='compare'>
|
|
<p>Clients MUST only compare the value of ID's for equality,
|
|
never for order. ID's MUST be compared for equality
|
|
octet-for-octet or codepoint-for-codepoint; a basic string
|
|
comparison with no extra canonicalization.</p>
|
|
</section2>
|
|
<section2 topic='Accepting Multiple IDs' anchor='multiple'>
|
|
<p>A client MAY send multiple id elements in an accceptance.
|
|
Clients that receive a notification with multiple IDs MUST process
|
|
each ID individually, as if multiple claims had been sent.</p>
|
|
</section2>
|
|
<section2 topic='When to send?' anchor='when'>
|
|
<p>To avoid race conditions and edge cases (including
|
|
invisibility), if both the client and server support the Mine
|
|
capability, the client SHOULD send ownership queries regardless
|
|
of whether or not the client sees other resources for the same
|
|
user online, or the capabilities of those other resources.</p>
|
|
</section2>
|
|
<section2 topic='Legacy Clients' anchor='unsupported_clients'>
|
|
<p>Clients that do not implement the Mine capability MAY be sent
|
|
notifications by the server. The server MAY be optimized to
|
|
avoid these notifications, however.</p>
|
|
</section2>
|
|
</section1>
|
|
<section1 topic='Implementation Notes' anchor='impl'>
|
|
<p>Some examples of events that might lead to a client sending an
|
|
ownsership claim:</p>
|
|
<ul>
|
|
<li>Clicking on a toast notification for the message</li>
|
|
<li>Bringing the client window to the front within a short time
|
|
after receiving the message, where the message is then displayed
|
|
to the user</li>
|
|
<li>Bringing the tab containing the message to the front</li>
|
|
<li>Beginning to type a response to the message</li>
|
|
<li>Closing the window containing the message at least several
|
|
seconds after the message was received</li>
|
|
<li>Clicking an accept button next to a message</li>
|
|
<li>Shutting down the screen saver while the message is in the
|
|
top-most window</li>
|
|
<li>A camera notices the user's eyes directed at the message</li>
|
|
</ul>
|
|
</section1>
|
|
<section1 topic='Accessibility Considerations' anchor='access'>
|
|
<p>Some care should be given to the events that can cause ownsership
|
|
claims, particularly in the MUC client implementations, such that
|
|
users with different abilities all have a chance to claim ownership.</p>
|
|
</section1>
|
|
<section1 topic='Security Considerations' anchor='security'>
|
|
<p>Clients MUST ignore acceptance notifications received from other users.</p>
|
|
</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>This XEP proposes the new namespace 'urn:xmpp:tmp:mine:0'.</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='urn:xmpp:tmp:mine:0'
|
|
xmlns='urn:xmpp:tmp:mine:0'
|
|
elementFormDefault='qualified'>
|
|
|
|
<xs:element name='whose'>
|
|
<xs:complexType>
|
|
<xs:attribute name='id' type='xs:string' use='required'/>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
|
|
<xs:element name='mine'>
|
|
<xs:complexType>
|
|
<xs:sequence>
|
|
<xs:element ref='id' minOccurs='1' maxOccurs='unbounded'/>
|
|
</xs:sequence>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
|
|
<xs:element name='id'>
|
|
<xs:complexType>
|
|
<xs:simpleContent>
|
|
<xs:extension base='xs:NMTOKEN'/>
|
|
</xs:simpleContent>
|
|
</xs:complexType>
|
|
</xs:element>
|
|
</xs:schema>
|
|
]]></code>
|
|
</section1>
|
|
</xep>
|