aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_proxy65.lua
blob: 1dcaf79bd790afb31e1dfa003619d4a217b1f6ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
-- Copyright (C) 2009 Thilo Cestonaro
-- 
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
--[[
* to restart the proxy in the console: e.g.
module:unload("proxy65");
> server.removeserver(<proxy65_port>);
module:load("proxy65", <proxy65_jid>);
]]--


local jid_split, jid_join, jid_compare = require "util.jid".split, require "util.jid".join, require "util.jid".compare;
local st = require "util.stanza";
local connlisteners = require "net.connlisteners";
local sha1 = require "util.hashes".sha1;
local server = require "net.server";

local host, name = module:get_host(), "SOCKS5 Bytestreams Service";
local sessions, transfers, replies_cache = {}, {}, {};

local proxy_port = module:get_option("proxy65_port") or 5000;
local proxy_interface = module:get_option("proxy65_interface") or "*";
local proxy_address = module:get_option("proxy65_address") or (proxy_interface ~= "*" and proxy_interface) or host;
local proxy_acl = module:get_option("proxy65_acl");
local max_buffer_size = 4096;

local connlistener = { default_port = proxy_port, default_interface = proxy_interface, default_mode = "*a" };

function connlistener.onincoming(conn, data)
	local session = sessions[conn] or {};
	
	if session.setup == nil and data ~= nil and data:sub(1):byte() == 0x05 and data:len() > 2 then
		local nmethods = data:sub(2):byte();
		local methods = data:sub(3);
		local supported = false;
		for i=1, nmethods, 1 do
			if(methods:sub(i):byte() == 0x00) then -- 0x00 == method: NO AUTH
				supported = true;
				break;
			end
		end
		if(supported) then
			module:log("debug", "new session found ... ")
			session.setup = true;
			sessions[conn] = session;
			conn:write(string.char(5, 0));
		end
		return;
	end
	if session.setup then
		if session.sha ~= nil and transfers[session.sha] ~= nil then
			local sha = session.sha;
			if transfers[sha].activated == true and transfers[sha].target ~= nil then
				if  transfers[sha].initiator == conn then
					transfers[sha].target:write(data);
				else
					transfers[sha].initiator:write(data);
				end
				return;
			end
		end
		if data ~= nil and data:len() == 0x2F and  -- 40 == length of SHA1 HASH, and 7 other bytes => 47 => 0x2F
			data:sub(1):byte() == 0x05 and -- SOCKS5 has 5 in first byte
			data:sub(2):byte() == 0x01 and -- CMD must be 1
			data:sub(3):byte() == 0x00 and -- RSV must be 0
			data:sub(4):byte() == 0x03 and -- ATYP must be 3
			data:sub(5):byte() == 40 and -- SHA1 HASH length must be 40 (0x28)
			data:sub(-2):byte() == 0x00 and -- PORT must be 0, size 2 byte
			data:sub(-1):byte() == 0x00
		then
			local sha = data:sub(6, 45); -- second param is not count! it's the ending index (included!)
			if transfers[sha] == nil then
				transfers[sha] = {};
				transfers[sha].activated = false;
				transfers[sha].target = conn;
				session.sha = sha;
				module:log("debug", "target connected ... ");
			elseif transfers[sha].target ~= nil then
				transfers[sha].initiator = conn;
				session.sha = sha;
				module:log("debug", "initiator connected ... ");
				server.link(conn, transfers[sha].target, max_buffer_size);
				server.link(transfers[sha].target, conn, max_buffer_size);
			end
			conn:write(string.char(5, 0, 0, 3, sha:len()) .. sha .. string.char(0, 0)); -- VER, REP, RSV, ATYP, BND.ADDR (sha), BND.PORT (2 Byte)
			conn:lock_read(true)
		else
			module:log("warn", "Neither data transfer nor initial connect of a participator of a transfer.")
			conn:close();
		end
	else
		if data ~= nil then
			module:log("warn", "unknown connection with no authentication data -> closing it");
			conn:close();
		end
	end
end

function connlistener.ondisconnect(conn, err)
	local session = sessions[conn];
	if session then
		if session.sha and transfers[session.sha] then
			local initiator, target = transfers[session.sha].initiator, transfers[session.sha].target;
			if initiator == conn and target ~= nil then
				target:close();
			elseif target == conn and initiator ~= nil then
			 	initiator:close();
			end
			transfers[session.sha] = nil;
		end
		-- Clean up any session-related stuff here
		sessions[conn] = nil;
	end
end

module:hook("iq-get/host/http://jabber.org/protocol/disco#info:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local reply = replies_cache.disco_info;
	if reply == nil then
	 	reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#info")
			:tag("identity", {category='proxy', type='bytestreams', name=name}):up()
			:tag("feature", {var="http://jabber.org/protocol/bytestreams"});
		replies_cache.disco_info = reply;
	end

	reply.attr.id = stanza.attr.id;
	reply.attr.to = stanza.attr.from;
	origin.send(reply);
	return true;
end, -1);

module:hook("iq-get/host/http://jabber.org/protocol/disco#items:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local reply = replies_cache.disco_items;
	if reply == nil then
	 	reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#items");
		replies_cache.disco_items = reply;
	end
	
	reply.attr.id = stanza.attr.id;
	reply.attr.to = stanza.attr.from;
	origin.send(reply);
	return true;
end, -1);

module:hook("iq-get/host/http://jabber.org/protocol/bytestreams:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local reply = replies_cache.stream_host;
	local err_reply = replies_cache.stream_host_err;
	local sid = stanza.tags[1].attr.sid;
	local allow = false;
	local jid = stanza.attr.from;
	
	if proxy_acl and #proxy_acl > 0 then
		for _, acl in ipairs(proxy_acl) do
			if jid_compare(jid, acl) then allow = true; end
		end
	else
		allow = true;
	end
	if allow == true then
		if reply == nil then
			reply = st.iq({type="result", from=host})
				:query("http://jabber.org/protocol/bytestreams")
				:tag("streamhost", {jid=host, host=proxy_address, port=proxy_port});
			replies_cache.stream_host = reply;
		end
	else
		module:log("warn", "Denying use of proxy for %s", tostring(jid));
		if err_reply == nil then
			err_reply = st.iq({type="error", from=host})
				:query("http://jabber.org/protocol/bytestreams")
				:tag("error", {code='403', type='auth'})
				:tag("forbidden", {xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'});
			replies_cache.stream_host_err = err_reply;
		end
		reply = err_reply;
	end
	reply.attr.id = stanza.attr.id;
	reply.attr.to = stanza.attr.from;
	reply.tags[1].attr.sid = sid;
	origin.send(reply);
	return true;
end);

module.unload = function()
	connlisteners.deregister(module.host .. ':proxy65');
end

local function set_activation(stanza)
	local from, to, sid, reply = nil;
	from = stanza.attr.from;
	if stanza.tags[1] ~= nil and tostring(stanza.tags[1].name) == "query" then
		if stanza.tags[1].attr ~= nil then
			sid = stanza.tags[1].attr.sid;
		end
		if stanza.tags[1].tags[1] ~= nil and tostring(stanza.tags[1].tags[1].name) == "activate" then
			to = stanza.tags[1].tags[1][1];
		end
	end
	if from ~= nil and to ~= nil and sid ~= nil then
		reply = st.iq({type="result", from=host, to=from});
		reply.attr.id = stanza.attr.id;
	end
	return reply, from, to, sid;
end

module:hook("iq-set/host/http://jabber.org/protocol/bytestreams:query", function(event)
	local origin, stanza = event.origin, event.stanza;

	module:log("debug", "Received activation request from %s", stanza.attr.from);
	local reply, from, to, sid = set_activation(stanza);
	if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
		local sha = sha1(sid .. from .. to, true);
		if transfers[sha] == nil then
			module:log("error", "transfers[sha]: nil");
		elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
			origin.send(reply);
			transfers[sha].activated = true;
			transfers[sha].target:lock_read(false);
			transfers[sha].initiator:lock_read(false);
		else
			module:log("debug", "Both parties were not yet connected");
			local message = "Neither party is connected to the proxy";
			if transfers[sha].initiator then
				message = "The recipient is not connected to the proxy";
			elseif transfers[sha].target then
				message = "The sender (you) is not connected to the proxy";
			end
			origin.send(st.error_reply(stanza, "cancel", "not-allowed", message));
		end
		return true;
	else
		module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
	end
end);

if not connlisteners.register(module.host .. ':proxy65', connlistener) then
	module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
	module:log("error", "Possibly two proxy65 components are configured to share the same port.");
end

connlisteners.start(module.host .. ':proxy65');