view mod_carbons/mod_carbons.lua @ 4738:5aee8d86629a

mod_bookmarks2: Fix handling of nick and password elements This form of child retrieval fails when the stanza elements internally don't have an 'xmlns' attribute, which can happen sometimes for some reason, including when they have been constructed via the stanza builder API. When that is the case then the explicit namespace arguemnt does not match the nil value of the internal attribute. Calling `:get_child()` without the namespace argument does the right thing here, with both nil and the parent namespace as valid values for the internal attribute.
author Kim Alvefur <zash@zash.se>
date Wed, 03 Nov 2021 21:11:55 +0100
parents 704e4845267b
children
line wrap: on
line source

-- XEP-0280: Message Carbons implementation for Prosody
-- Copyright (C) 2011-2016 Kim Alvefur
--
-- This file is MIT/X11 licensed.

local st = require "util.stanza";
local jid_bare = require "util.jid".bare;
local xmlns_carbons = "urn:xmpp:carbons:2";
local xmlns_carbons_old = "urn:xmpp:carbons:1";
local xmlns_carbons_really_old = "urn:xmpp:carbons:0";
local xmlns_forward = "urn:xmpp:forward:0";
local full_sessions, bare_sessions = prosody.full_sessions, prosody.bare_sessions;

local function toggle_carbons(event)
	local origin, stanza = event.origin, event.stanza;
	local state = stanza.tags[1].attr.mode or stanza.tags[1].name;
	module:log("debug", "%s %sd carbons", origin.full_jid, state);
	origin.want_carbons = state == "enable" and stanza.tags[1].attr.xmlns;
	origin.send(st.reply(stanza));
	return true;
end
module:hook("iq-set/self/"..xmlns_carbons..":disable", toggle_carbons);
module:hook("iq-set/self/"..xmlns_carbons..":enable", toggle_carbons);

-- COMPAT
module:hook("iq-set/self/"..xmlns_carbons_old..":disable", toggle_carbons);
module:hook("iq-set/self/"..xmlns_carbons_old..":enable", toggle_carbons);
module:hook("iq-set/self/"..xmlns_carbons_really_old..":carbons", toggle_carbons);

local function message_handler(event, c2s)
	local origin, stanza = event.origin, event.stanza;
	local orig_type = stanza.attr.type or "normal";
	local orig_from = stanza.attr.from;
	local orig_to = stanza.attr.to;

	if not(orig_type == "chat" or (orig_type == "normal" and stanza:get_child("body"))) then
		return -- Only chat type messages
	end

	-- Stanza sent by a local client
	local bare_jid = jid_bare(orig_from);
	local target_session = origin;
	local top_priority = false;
	local user_sessions = bare_sessions[bare_jid];

	-- Stanza about to be delivered to a local client
	if not c2s then
		bare_jid = jid_bare(orig_to);
		target_session = full_sessions[orig_to];
		user_sessions = bare_sessions[bare_jid];
		if not target_session and user_sessions then
			-- The top resources will already receive this message per normal routing rules,
			-- so we are going to skip them in order to avoid sending duplicated messages.
			local top_resources = user_sessions.top_resources;
			top_priority = top_resources and top_resources[1].priority
		end
	end

	if not user_sessions then
		module:log("debug", "Skip carbons for offline user");
		return -- No use in sending carbons to an offline user
	end

	if stanza:get_child("private", xmlns_carbons) then
		if not c2s then
			stanza:maptags(function(tag)
				if not ( tag.attr.xmlns == xmlns_carbons and tag.name == "private" ) then
					return tag;
				end
			end);
		end
		module:log("debug", "Message tagged private, ignoring");
		return
	elseif stanza:get_child("no-copy", "urn:xmpp:hints") then
		module:log("debug", "Message has no-copy hint, ignoring");
		return
	elseif not c2s and bare_jid == orig_from and stanza:get_child("x", "http://jabber.org/protocol/muc#user") then
		module:log("debug", "MUC PM, ignoring");
		return
	end

	-- Create the carbon copy and wrap it as per the Stanza Forwarding XEP
	local copy = st.clone(stanza);
	copy.attr.xmlns = "jabber:client";
	local carbon = st.message{ from = bare_jid, type = orig_type, }
		:tag(c2s and "sent" or "received", { xmlns = xmlns_carbons })
			:tag("forwarded", { xmlns = xmlns_forward })
				:add_child(copy):reset();

	-- COMPAT
	local carbon_old = st.message{ from = bare_jid, type = orig_type, }
		:tag(c2s and "sent" or "received", { xmlns = xmlns_carbons_old }):up()
		:tag("forwarded", { xmlns = xmlns_forward })
			:add_child(copy):reset();

	-- COMPAT
	local carbon_really_old = st.clone(stanza)
		:tag(c2s and "sent" or "received", { xmlns = xmlns_carbons_really_old }):up()

	user_sessions = user_sessions and user_sessions.sessions;
	for _, session in pairs(user_sessions) do
		-- Carbons are sent to resources that have enabled it
		if session.want_carbons
		-- but not the resource that sent the message, or the one that it's directed to
		and session ~= target_session
		-- and isn't among the top resources that would receive the message per standard routing rules
		and (c2s or session.priority ~= top_priority)
		-- don't send v0 carbons (or copies) for c2s
		and (not c2s or session.want_carbons ~= xmlns_carbons_really_old) then
			carbon.attr.to = session.full_jid;
			module:log("debug", "Sending carbon to %s", session.full_jid);
			local carbon = session.want_carbons == xmlns_carbons_old and carbon_old -- COMPAT
			or session.want_carbons == xmlns_carbons_really_old and carbon_really_old -- COMPAT
			or carbon;
			session.send(carbon);
		end
	end
end

local function c2s_message_handler(event)
	return message_handler(event, true)
end

-- Stanzas sent by local clients
module:hook("pre-message/host", c2s_message_handler, 0.05); -- priority between mod_message (0 in 0.9) and mod_firewall (0.1)
module:hook("pre-message/bare", c2s_message_handler, 0.05);
module:hook("pre-message/full", c2s_message_handler, 0.05);
-- Stanzas to local clients
module:hook("message/bare", message_handler, 0.05);
module:hook("message/full", message_handler, 0.05);

module:add_feature(xmlns_carbons);
module:add_feature(xmlns_carbons_old);
if module:get_option_boolean("carbons_v0") then
	module:add_feature(xmlns_carbons_really_old);
end