1 -- XEP-0280: Message Carbons implementation for Prosody
2 -- Copyright (C) 2011 Kim Alvefur
4 -- This file is MIT/X11 licensed.
6 local st = require "util.stanza";
7 local jid_bare = require "util.jid".bare;
8 local xmlns_carbons = "urn:xmpp:carbons:2";
9 local xmlns_forward = "urn:xmpp:forward:0";
10 local full_sessions, bare_sessions = full_sessions, bare_sessions;
12 local function toggle_carbons(event)
13 local origin, stanza = event.origin, event.stanza;
14 local state = stanza.tags[1].name;
15 module:log("debug", "%s %sd carbons", origin.full_jid, state);
16 origin.want_carbons = state == "enable" and stanza.tags[1].attr.xmlns;
17 return origin.send(st.reply(stanza));
19 module:hook("iq-set/self/"..xmlns_carbons..":disable", toggle_carbons);
20 module:hook("iq-set/self/"..xmlns_carbons..":enable", toggle_carbons);
22 local function message_handler(event, c2s)
23 local origin, stanza = event.origin, event.stanza;
24 local orig_type = stanza.attr.type;
25 local orig_from = stanza.attr.from;
26 local orig_to = stanza.attr.to;
28 if not (orig_type == nil
29 or orig_type == "normal"
30 or orig_type == "chat") then
31 return -- No carbons for messages of type error or headline
34 -- Stanza sent by a local client
35 local bare_jid = jid_bare(orig_from);
36 local target_session = origin;
37 local top_priority = false;
38 local user_sessions = bare_sessions[bare_jid];
40 -- Stanza about to be delivered to a local client
42 bare_jid = jid_bare(orig_to);
43 target_session = full_sessions[orig_to];
44 user_sessions = bare_sessions[bare_jid];
45 if not target_session and user_sessions then
46 -- The top resources will already receive this message per normal routing rules,
47 -- so we are going to skip them in order to avoid sending duplicated messages.
48 local top_resources = user_sessions.top_resources;
49 top_priority = top_resources and top_resources[1].priority
53 if not user_sessions then
54 module:log("debug", "Skip carbons for offline user");
55 return -- No use in sending carbons to an offline user
58 if stanza:get_child("private", xmlns_carbons) then
60 stanza:maptags(function(tag)
61 if not ( tag.attr.xmlns == xmlns_carbons and tag.name == "private" ) then
66 module:log("debug", "Message tagged private, ignoring");
68 elseif stanza:get_child("no-copy", "urn:xmpp:hints") then
69 module:log("debug", "Message has no-copy hint, ignoring");
71 elseif stanza:get_child("x", "http://jabber.org/protocol/muc#user") then
72 module:log("debug", "MUC PM, ignoring");
76 -- Create the carbon copy and wrap it as per the Stanza Forwarding XEP
77 local copy = st.clone(stanza);
78 copy.attr.xmlns = "jabber:client";
79 local carbon = st.message{ from = bare_jid, type = orig_type, }
80 :tag(c2s and "sent" or "received", { xmlns = xmlns_carbons })
81 :tag("forwarded", { xmlns = xmlns_forward })
82 :add_child(copy):reset();
84 user_sessions = user_sessions and user_sessions.sessions;
85 for _, session in pairs(user_sessions) do
86 -- Carbons are sent to resources that have enabled it
87 if session.want_carbons
88 -- but not the resource that sent the message, or the one that it's directed to
89 and session ~= target_session
90 -- and isn't among the top resources that would receive the message per standard routing rules
91 and (c2s or session.priority ~= top_priority) then
92 carbon.attr.to = session.full_jid;
93 module:log("debug", "Sending carbon to %s", session.full_jid);
99 local function c2s_message_handler(event)
100 return message_handler(event, true)
103 -- Stanzas sent by local clients
104 module:hook("pre-message/host", c2s_message_handler, 1);
105 module:hook("pre-message/bare", c2s_message_handler, 1);
106 module:hook("pre-message/full", c2s_message_handler, 1);
107 -- Stanzas to local clients
108 module:hook("message/bare", message_handler, 1);
109 module:hook("message/full", message_handler, 1);
111 module:add_feature(xmlns_carbons);