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 if module:get_host_type() ~= "component" then
  14         error("proxy65 should be loaded as a component, please see http://prosody.im/doc/components", 0);
  15 end
  16
  17 local jid_split, jid_join, jid_compare = require "util.jid".split, require "util.jid".join, require "util.jid".compare;
  18 local st = require "util.stanza";
  19 local connlisteners = require "net.connlisteners";
  20 local sha1 = require "util.hashes".sha1;
  21 local server = require "net.server";
  22
  23 local host, name = module:get_host(), "SOCKS5 Bytestreams Service";
  24 local sessions, transfers, component, replies_cache = {}, {}, nil, {};
  25
  26 local proxy_port = module:get_option("proxy65_port") or 5000;
  27 local proxy_interface = module:get_option("proxy65_interface") or "*";
  28 local proxy_address = module:get_option("proxy65_address") or (proxy_interface ~= "*" and proxy_interface) or host;
  29 local proxy_acl = module:get_option("proxy65_acl");
  30 local max_buffer_size = 4096;
  31
  32 local connlistener = { default_port = proxy_port, default_interface = proxy_interface, default_mode = "*a" };
  33
  34 function connlistener.onincoming(conn, data)
  35         local session = sessions[conn] or {};
  36
  37         if session.setup == nil and data ~= nil and data:sub(1):byte() == 0x05 and data:len() > 2 then
  38                 local nmethods = data:sub(2):byte();
  39                 local methods = data:sub(3);
  40                 local supported = false;
  41                 for i=1, nmethods, 1 do
  42                         if(methods:sub(i):byte() == 0x00) then -- 0x00 == method: NO AUTH
  43                                 supported = true;
  44                                 break;
  45                         end
  46                 end
  47                 if(supported) then
  48                         module:log("debug", "new session found ... ")
  49                         session.setup = true;
  50                         sessions[conn] = session;
  51                         conn:write(string.char(5, 0));
  52                 end
  53                 return;
  54         end
  55         if session.setup then
  56                 if session.sha ~= nil and transfers[session.sha] ~= nil then
  57                         local sha = session.sha;
  58                         if transfers[sha].activated == true and transfers[sha].target ~= nil then
  59                                 if  transfers[sha].initiator == conn then
  60                                         transfers[sha].target:write(data);
  61                                 else
  62                                         transfers[sha].initiator:write(data);
  63                                 end
  64                                 return;
  65                         end
  66                 end
  67                 if data ~= nil and data:len() == 0x2F and  -- 40 == length of SHA1 HASH, and 7 other bytes => 47 => 0x2F
  68                         data:sub(1):byte() == 0x05 and -- SOCKS5 has 5 in first byte
  69                         data:sub(2):byte() == 0x01 and -- CMD must be 1
  70                         data:sub(3):byte() == 0x00 and -- RSV must be 0
  71                         data:sub(4):byte() == 0x03 and -- ATYP must be 3
  72                         data:sub(5):byte() == 40 and -- SHA1 HASH length must be 40 (0x28)
  73                         data:sub(-2):byte() == 0x00 and -- PORT must be 0, size 2 byte
  74                         data:sub(-1):byte() == 0x00
  75                 then
  76                         local sha = data:sub(6, 45); -- second param is not count! it's the ending index (included!)
  77                         if transfers[sha] == nil then
  78                                 transfers[sha] = {};
  79                                 transfers[sha].activated = false;
  80                                 transfers[sha].target = conn;
  81                                 session.sha = sha;
  82                                 module:log("debug", "target connected ... ");
  83                         elseif transfers[sha].target ~= nil then
  84                                 transfers[sha].initiator = conn;
  85                                 session.sha = sha;
  86                                 module:log("debug", "initiator connected ... ");
  87                                 server.link(conn, transfers[sha].target, max_buffer_size);
  88                                 server.link(transfers[sha].target, conn, max_buffer_size);
  89                         end
  90                         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)
  91                         conn:lock_read(true)
  92                 else
  93                         module:log("warn", "Neither data transfer nor initial connect of a participator of a transfer.")
  94                         conn:close();
  95                 end
  96         else
  97                 if data ~= nil then
  98                         module:log("warn", "unknown connection with no authentication data -> closing it");
  99                         conn:close();
 100                 end
 101         end
 102 end
 103
 104 function connlistener.ondisconnect(conn, err)
 105         local session = sessions[conn];
 106         if session then
 107                 if session.sha and transfers[session.sha] then
 108                         local initiator, target = transfers[session.sha].initiator, transfers[session.sha].target;
 109                         if initiator == conn and target ~= nil then
 110                                 target:close();
 111                         elseif target == conn and initiator ~= nil then
 112                                 initiator:close();
 113                         end
 114                         transfers[session.sha] = nil;
 115                 end
 116                 -- Clean up any session-related stuff here
 117                 sessions[conn] = nil;
 118         end
 119 end
 120
 121 local function get_disco_info(stanza)
 122         local reply = replies_cache.disco_info;
 123         if reply == nil then
 124                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#info")
 125                         :tag("identity", {category='proxy', type='bytestreams', name=name}):up()
 126                         :tag("feature", {var="http://jabber.org/protocol/bytestreams"});
 127                 replies_cache.disco_info = reply;
 128         end
 129
 130         reply.attr.id = stanza.attr.id;
 131         reply.attr.to = stanza.attr.from;
 132         return reply;
 133 end
 134
 135 local function get_disco_items(stanza)
 136         local reply = replies_cache.disco_items;
 137         if reply == nil then
 138                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#items");
 139                 replies_cache.disco_items = reply;
 140         end
 141
 142         reply.attr.id = stanza.attr.id;
 143         reply.attr.to = stanza.attr.from;
 144         return reply;
 145 end
 146
 147 local function get_stream_host(origin, stanza)
 148         local reply = replies_cache.stream_host;
 149         local err_reply = replies_cache.stream_host_err;
 150         local sid = stanza.tags[1].attr.sid;
 151         local allow = false;
 152         local jid = stanza.attr.from;
 153
 154         if proxy_acl and #proxy_acl > 0 then
 155                 for _, acl in ipairs(proxy_acl) do
 156                         if jid_compare(jid, acl) then allow = true; end
 157                 end
 158         else
 159                 allow = true;
 160         end
 161         if allow == true then
 162                 if reply == nil then
 163                         reply = st.iq({type="result", from=host})
 164                                 :query("http://jabber.org/protocol/bytestreams")
 165                                 :tag("streamhost", {jid=host, host=proxy_address, port=proxy_port});
 166                         replies_cache.stream_host = reply;
 167                 end
 168         else
 169                 module:log("warn", "Denying use of proxy for %s", tostring(jid));
 170                 if err_reply == nil then
 171                         err_reply = st.iq({type="error", from=host})
 172                                 :query("http://jabber.org/protocol/bytestreams")
 173                                 :tag("error", {code='403', type='auth'})
 174                                 :tag("forbidden", {xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'});
 175                         replies_cache.stream_host_err = err_reply;
 176                 end
 177                 reply = err_reply;
 178         end
 179         reply.attr.id = stanza.attr.id;
 180         reply.attr.to = stanza.attr.from;
 181         reply.tags[1].attr.sid = sid;
 182         return reply;
 183 end
 184
 185 module.unload = function()
 186         connlisteners.deregister(module.host .. ':proxy65');
 187 end
 188
 189 local function set_activation(stanza)
 190         local from, to, sid, reply = nil;
 191         from = stanza.attr.from;
 192         if stanza.tags[1] ~= nil and tostring(stanza.tags[1].name) == "query" then
 193                 if stanza.tags[1].attr ~= nil then
 194                         sid = stanza.tags[1].attr.sid;
 195                 end
 196                 if stanza.tags[1].tags[1] ~= nil and tostring(stanza.tags[1].tags[1].name) == "activate" then
 197                         to = stanza.tags[1].tags[1][1];
 198                 end
 199         end
 200         if from ~= nil and to ~= nil and sid ~= nil then
 201                 reply = st.iq({type="result", from=host, to=from});
 202                 reply.attr.id = stanza.attr.id;
 203         end
 204         return reply, from, to, sid;
 205 end
 206
 207 function handle_to_domain(event)
 208         local origin, stanza = event.origin, event.stanza;
 209         if stanza.attr.type == "get" then
 210                 local xmlns = stanza.tags[1].attr.xmlns
 211                 if xmlns == "http://jabber.org/protocol/disco#info" then
 212                         origin.send(get_disco_info(stanza));
 213                         return true;
 214                 elseif xmlns == "http://jabber.org/protocol/disco#items" then
 215                         origin.send(get_disco_items(stanza));
 216                         return true;
 217                 elseif xmlns == "http://jabber.org/protocol/bytestreams" then
 218                         origin.send(get_stream_host(origin, stanza));
 219                         return true;
 220                 else
 221                         origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
 222                         return true;
 223                 end
 224         else -- stanza.attr.type == "set"
 225                 module:log("debug", "Received activation request from %s", stanza.attr.from);
 226                 local reply, from, to, sid = set_activation(stanza);
 227                 if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
 228                         local sha = sha1(sid .. from .. to, true);
 229                         if transfers[sha] == nil then
 230                                 module:log("error", "transfers[sha]: nil");
 231                         elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
 232                                 origin.send(reply);
 233                                 transfers[sha].activated = true;
 234                                 transfers[sha].target:lock_read(false);
 235                                 transfers[sha].initiator:lock_read(false);
 236                         else
 237                                 module:log("debug", "Both parties were not yet connected");
 238                                 local message = "Neither party is connected to the proxy";
 239                                 if transfers[sha].initiator then
 240                                         message = "The recipient is not connected to the proxy";
 241                                 elseif transfers[sha].target then
 242                                         message = "The sender (you) is not connected to the proxy";
 243                                 end
 244                                 origin.send(st.error_reply(stanza, "cancel", "not-allowed", message));
 245                         end
 246                         return true;
 247                 else
 248                         module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
 249                 end
 250         end
 251 end
 252 module:hook("iq/host", handle_to_domain, -1);
 253
 254 if not connlisteners.register(module.host .. ':proxy65', connlistener) then
 255         module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
 256         module:log("error", "Possibly two proxy65 components are configured to share the same port.");
 257 end
 258
 259 connlisteners.start(module.host .. ':proxy65');