plugins/mod_proxy65.lua

   1 -- Copyright (C) 2009 Thilo Cestonaro
   2 --
   3 -- This project is MIT/X11 licensed. Please see the
   4 -- COPYING file in the source package for more information.
   5 --
   6 --[[
   7 * to restart the proxy in the console: e.g.
   8 module:unload("proxy65");
   9 > server.removeserver(<proxy65_port>);
  10 module:load("proxy65", <proxy65_jid>);
  11 ]]--
  12
  13
  14 local module = module;
  15 local tostring = tostring;
  16 local jid_split, jid_join, jid_compare = require "util.jid".split, require "util.jid".join, require "util.jid".compare;
  17 local st = require "util.stanza";
  18 local connlisteners = require "net.connlisteners";
  19 local sha1 = require "util.hashes".sha1;
  20 local server = require "net.server";
  21
  22 local host, name = module:get_host(), "SOCKS5 Bytestreams Service";
  23 local sessions, transfers, replies_cache = {}, {}, {};
  24
  25 local proxy_port = module:get_option("proxy65_port") or 5000;
  26 local proxy_interface = module:get_option("proxy65_interface") or "*";
  27 local proxy_address = module:get_option("proxy65_address") or (proxy_interface ~= "*" and proxy_interface) or host;
  28 local proxy_acl = module:get_option("proxy65_acl");
  29 local max_buffer_size = 4096;
  30
  31 local connlistener = { default_port = proxy_port, default_interface = proxy_interface, default_mode = "*a" };
  32
  33 function connlistener.onincoming(conn, data)
  34         local session = sessions[conn] or {};
  35
  36         if session.setup == nil and data ~= nil and data:byte(1) == 0x05 and #data > 2 then
  37                 local nmethods = data:byte(2);
  38                 local methods = data:sub(3);
  39                 local supported = false;
  40                 for i=1, nmethods, 1 do
  41                         if(methods:byte(i) == 0x00) then -- 0x00 == method: NO AUTH
  42                                 supported = true;
  43                                 break;
  44                         end
  45                 end
  46                 if(supported) then
  47                         module:log("debug", "new session found ... ")
  48                         session.setup = true;
  49                         sessions[conn] = session;
  50                         conn:write(string.char(5, 0));
  51                 end
  52                 return;
  53         end
  54         if session.setup then
  55                 if session.sha ~= nil and transfers[session.sha] ~= nil then
  56                         local sha = session.sha;
  57                         if transfers[sha].activated == true and transfers[sha].target ~= nil then
  58                                 if  transfers[sha].initiator == conn then
  59                                         transfers[sha].target:write(data);
  60                                 else
  61                                         transfers[sha].initiator:write(data);
  62                                 end
  63                                 return;
  64                         end
  65                 end
  66                 if data ~= nil and #data == 0x2F and  -- 40 == length of SHA1 HASH, and 7 other bytes => 47 => 0x2F
  67                         data:byte(1) == 0x05 and -- SOCKS5 has 5 in first byte
  68                         data:byte(2) == 0x01 and -- CMD must be 1
  69                         data:byte(3) == 0x00 and -- RSV must be 0
  70                         data:byte(4) == 0x03 and -- ATYP must be 3
  71                         data:byte(5) == 40 and -- SHA1 HASH length must be 40 (0x28)
  72                         data:byte(-2) == 0x00 and -- PORT must be 0, size 2 byte
  73                         data:byte(-1) == 0x00
  74                 then
  75                         local sha = data:sub(6, 45); -- second param is not count! it's the ending index (included!)
  76                         if transfers[sha] == nil then
  77                                 transfers[sha] = {};
  78                                 transfers[sha].activated = false;
  79                                 transfers[sha].target = conn;
  80                                 session.sha = sha;
  81                                 module:log("debug", "target connected ... ");
  82                         elseif transfers[sha].target ~= nil then
  83                                 transfers[sha].initiator = conn;
  84                                 session.sha = sha;
  85                                 module:log("debug", "initiator connected ... ");
  86                                 server.link(conn, transfers[sha].target, max_buffer_size);
  87                                 server.link(transfers[sha].target, conn, max_buffer_size);
  88                         end
  89                         conn:write(string.char(5, 0, 0, 3, #sha) .. sha .. string.char(0, 0)); -- VER, REP, RSV, ATYP, BND.ADDR (sha), BND.PORT (2 Byte)
  90                         conn:lock_read(true)
  91                 else
  92                         module:log("warn", "Neither data transfer nor initial connect of a participator of a transfer.")
  93                         conn:close();
  94                 end
  95         else
  96                 if data ~= nil then
  97                         module:log("warn", "unknown connection with no authentication data -> closing it");
  98                         conn:close();
  99                 end
 100         end
 101 end
 102
 103 function connlistener.ondisconnect(conn, err)
 104         local session = sessions[conn];
 105         if session then
 106                 if session.sha and transfers[session.sha] then
 107                         local initiator, target = transfers[session.sha].initiator, transfers[session.sha].target;
 108                         if initiator == conn and target ~= nil then
 109                                 target:close();
 110                         elseif target == conn and initiator ~= nil then
 111                                 initiator:close();
 112                         end
 113                         transfers[session.sha] = nil;
 114                 end
 115                 -- Clean up any session-related stuff here
 116                 sessions[conn] = nil;
 117         end
 118 end
 119
 120 module:add_identity("proxy", "bytestreams", name);
 121 module:add_feature("http://jabber.org/protocol/bytestreams");
 122
 123 module:hook("iq-get/host/http://jabber.org/protocol/disco#info:query", function(event)
 124         local origin, stanza = event.origin, event.stanza;
 125         local reply = replies_cache.disco_info;
 126         if reply == nil then
 127                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#info")
 128                         :tag("identity", {category='proxy', type='bytestreams', name=name}):up()
 129                         :tag("feature", {var="http://jabber.org/protocol/bytestreams"});
 130                 replies_cache.disco_info = reply;
 131         end
 132
 133         reply.attr.id = stanza.attr.id;
 134         reply.attr.to = stanza.attr.from;
 135         origin.send(reply);
 136         return true;
 137 end, -1);
 138
 139 module:hook("iq-get/host/http://jabber.org/protocol/disco#items:query", function(event)
 140         local origin, stanza = event.origin, event.stanza;
 141         local reply = replies_cache.disco_items;
 142         if reply == nil then
 143                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#items");
 144                 replies_cache.disco_items = reply;
 145         end
 146
 147         reply.attr.id = stanza.attr.id;
 148         reply.attr.to = stanza.attr.from;
 149         origin.send(reply);
 150         return true;
 151 end, -1);
 152
 153 module:hook("iq-get/host/http://jabber.org/protocol/bytestreams:query", function(event)
 154         local origin, stanza = event.origin, event.stanza;
 155         local reply = replies_cache.stream_host;
 156         local err_reply = replies_cache.stream_host_err;
 157         local sid = stanza.tags[1].attr.sid;
 158         local allow = false;
 159         local jid = stanza.attr.from;
 160
 161         if proxy_acl and #proxy_acl > 0 then
 162                 for _, acl in ipairs(proxy_acl) do
 163                         if jid_compare(jid, acl) then allow = true; end
 164                 end
 165         else
 166                 allow = true;
 167         end
 168         if allow == true then
 169                 if reply == nil then
 170                         reply = st.iq({type="result", from=host})
 171                                 :query("http://jabber.org/protocol/bytestreams")
 172                                 :tag("streamhost", {jid=host, host=proxy_address, port=proxy_port});
 173                         replies_cache.stream_host = reply;
 174                 end
 175         else
 176                 module:log("warn", "Denying use of proxy for %s", tostring(jid));
 177                 if err_reply == nil then
 178                         err_reply = st.iq({type="error", from=host})
 179                                 :query("http://jabber.org/protocol/bytestreams")
 180                                 :tag("error", {code='403', type='auth'})
 181                                 :tag("forbidden", {xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'});
 182                         replies_cache.stream_host_err = err_reply;
 183                 end
 184                 reply = err_reply;
 185         end
 186         reply.attr.id = stanza.attr.id;
 187         reply.attr.to = stanza.attr.from;
 188         reply.tags[1].attr.sid = sid;
 189         origin.send(reply);
 190         return true;
 191 end);
 192
 193 module.unload = function()
 194         connlisteners.deregister(module.host .. ':proxy65');
 195 end
 196
 197 local function set_activation(stanza)
 198         local to, reply;
 199         local from = stanza.attr.from;
 200         local query = stanza.tags[1];
 201         local sid = query.attr.sid;
 202         if query.tags[1] and query.tags[1].name == "activate" then
 203                 to = query.tags[1][1];
 204         end
 205         if from ~= nil and to ~= nil and sid ~= nil then
 206                 reply = st.iq({type="result", from=host, to=from});
 207                 reply.attr.id = stanza.attr.id;
 208         end
 209         return reply, from, to, sid;
 210 end
 211
 212 module:hook("iq-set/host/http://jabber.org/protocol/bytestreams:query", function(event)
 213         local origin, stanza = event.origin, event.stanza;
 214
 215         module:log("debug", "Received activation request from %s", stanza.attr.from);
 216         local reply, from, to, sid = set_activation(stanza);
 217         if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
 218                 local sha = sha1(sid .. from .. to, true);
 219                 if transfers[sha] == nil then
 220                         module:log("error", "transfers[sha]: nil");
 221                 elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
 222                         origin.send(reply);
 223                         transfers[sha].activated = true;
 224                         transfers[sha].target:lock_read(false);
 225                         transfers[sha].initiator:lock_read(false);
 226                 else
 227                         module:log("debug", "Both parties were not yet connected");
 228                         local message = "Neither party is connected to the proxy";
 229                         if transfers[sha].initiator then
 230                                 message = "The recipient is not connected to the proxy";
 231                         elseif transfers[sha].target then
 232                                 message = "The sender (you) is not connected to the proxy";
 233                         end
 234                         origin.send(st.error_reply(stanza, "cancel", "not-allowed", message));
 235                 end
 236                 return true;
 237         else
 238                 module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
 239         end
 240 end);
 241
 242 if not connlisteners.register(module.host .. ':proxy65', connlistener) then
 243         module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
 244         module:log("error", "Possibly two proxy65 components are configured to share the same port.");
 245 end
 246
 247 connlisteners.start(module.host .. ':proxy65');