mod_carbons/mod_carbons.lua

   1 -- XEP-0280: Message Carbons implementation for Prosody
   2 -- Copyright (C) 2011-2016 Kim Alvefur
   3 --
   4 -- This file is MIT/X11 licensed.
   5
   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_carbons_old = "urn:xmpp:carbons:1";
  10 local xmlns_carbons_really_old = "urn:xmpp:carbons:0";
  11 local xmlns_forward = "urn:xmpp:forward:0";
  12 local full_sessions, bare_sessions = prosody.full_sessions, prosody.bare_sessions;
  13
  14 local function toggle_carbons(event)
  15         local origin, stanza = event.origin, event.stanza;
  16         local state = stanza.tags[1].attr.mode or stanza.tags[1].name;
  17         module:log("debug", "%s %sd carbons", origin.full_jid, state);
  18         origin.want_carbons = state == "enable" and stanza.tags[1].attr.xmlns;
  19         origin.send(st.reply(stanza));
  20         return true;
  21 end
  22 module:hook("iq-set/self/"..xmlns_carbons..":disable", toggle_carbons);
  23 module:hook("iq-set/self/"..xmlns_carbons..":enable", toggle_carbons);
  24
  25 -- COMPAT
  26 module:hook("iq-set/self/"..xmlns_carbons_old..":disable", toggle_carbons);
  27 module:hook("iq-set/self/"..xmlns_carbons_old..":enable", toggle_carbons);
  28 module:hook("iq-set/self/"..xmlns_carbons_really_old..":carbons", toggle_carbons);
  29
  30 local function message_handler(event, c2s)
  31         local origin, stanza = event.origin, event.stanza;
  32         local orig_type = stanza.attr.type or "normal";
  33         local orig_from = stanza.attr.from;
  34         local orig_to = stanza.attr.to;
  35
  36         if not(orig_type == "chat" or (orig_type == "normal" and stanza:get_child("body"))) then
  37                 return -- Only chat type messages
  38         end
  39
  40         -- Stanza sent by a local client
  41         local bare_jid = jid_bare(orig_from);
  42         local target_session = origin;
  43         local top_priority = false;
  44         local user_sessions = bare_sessions[bare_jid];
  45
  46         -- Stanza about to be delivered to a local client
  47         if not c2s then
  48                 bare_jid = jid_bare(orig_to);
  49                 target_session = full_sessions[orig_to];
  50                 user_sessions = bare_sessions[bare_jid];
  51                 if not target_session and user_sessions then
  52                         -- The top resources will already receive this message per normal routing rules,
  53                         -- so we are going to skip them in order to avoid sending duplicated messages.
  54                         local top_resources = user_sessions.top_resources;
  55                         top_priority = top_resources and top_resources[1].priority
  56                 end
  57         end
  58
  59         if not user_sessions then
  60                 module:log("debug", "Skip carbons for offline user");
  61                 return -- No use in sending carbons to an offline user
  62         end
  63
  64         if stanza:get_child("private", xmlns_carbons) then
  65                 if not c2s then
  66                         stanza:maptags(function(tag)
  67                                 if not ( tag.attr.xmlns == xmlns_carbons and tag.name == "private" ) then
  68                                         return tag;
  69                                 end
  70                         end);
  71                 end
  72                 module:log("debug", "Message tagged private, ignoring");
  73                 return
  74         elseif stanza:get_child("no-copy", "urn:xmpp:hints") then
  75                 module:log("debug", "Message has no-copy hint, ignoring");
  76                 return
  77         elseif not c2s and bare_jid == orig_from and stanza:get_child("x", "http://jabber.org/protocol/muc#user") then
  78                 module:log("debug", "MUC PM, ignoring");
  79                 return
  80         end
  81
  82         -- Create the carbon copy and wrap it as per the Stanza Forwarding XEP
  83         local copy = st.clone(stanza);
  84         copy.attr.xmlns = "jabber:client";
  85         local carbon = st.message{ from = bare_jid, type = orig_type, }
  86                 :tag(c2s and "sent" or "received", { xmlns = xmlns_carbons })
  87                         :tag("forwarded", { xmlns = xmlns_forward })
  88                                 :add_child(copy):reset();
  89
  90         -- COMPAT
  91         local carbon_old = st.message{ from = bare_jid, type = orig_type, }
  92                 :tag(c2s and "sent" or "received", { xmlns = xmlns_carbons_old }):up()
  93                 :tag("forwarded", { xmlns = xmlns_forward })
  94                         :add_child(copy):reset();
  95
  96         -- COMPAT
  97         local carbon_really_old = st.clone(stanza)
  98                 :tag(c2s and "sent" or "received", { xmlns = xmlns_carbons_really_old }):up()
  99
 100         user_sessions = user_sessions and user_sessions.sessions;
 101         for _, session in pairs(user_sessions) do
 102                 -- Carbons are sent to resources that have enabled it
 103                 if session.want_carbons
 104                 -- but not the resource that sent the message, or the one that it's directed to
 105                 and session ~= target_session
 106                 -- and isn't among the top resources that would receive the message per standard routing rules
 107                 and (c2s or session.priority ~= top_priority)
 108                 -- don't send v0 carbons (or copies) for c2s
 109                 and (not c2s or session.want_carbons ~= xmlns_carbons_really_old) then
 110                         carbon.attr.to = session.full_jid;
 111                         module:log("debug", "Sending carbon to %s", session.full_jid);
 112                         local carbon = session.want_carbons == xmlns_carbons_old and carbon_old -- COMPAT
 113                         or session.want_carbons == xmlns_carbons_really_old and carbon_really_old -- COMPAT
 114                         or carbon;
 115                         session.send(carbon);
 116                 end
 117         end
 118 end
 119
 120 local function c2s_message_handler(event)
 121         return message_handler(event, true)
 122 end
 123
 124 -- Stanzas sent by local clients
 125 module:hook("pre-message/host", c2s_message_handler, 0.05); -- priority between mod_message (0 in 0.9) and mod_firewall (0.1)
 126 module:hook("pre-message/bare", c2s_message_handler, 0.05);
 127 module:hook("pre-message/full", c2s_message_handler, 0.05);
 128 -- Stanzas to local clients
 129 module:hook("message/bare", message_handler, 0.05);
 130 module:hook("message/full", message_handler, 0.05);
 131
 132 module:add_feature(xmlns_carbons);
 133 module:add_feature(xmlns_carbons_old);
 134 if module:get_option_boolean("carbons_v0") then
 135         module:add_feature(xmlns_carbons_really_old);
 136 end