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 = {}, {};
  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         origin.send(st.reply(stanza):query("http://jabber.org/protocol/disco#info")
 126                 :tag("identity", {category='proxy', type='bytestreams', name=name}):up()
 127                 :tag("feature", {var="http://jabber.org/protocol/bytestreams"}) );
 128         return true;
 129 end, -1);
 130
 131 module:hook("iq-get/host/http://jabber.org/protocol/disco#items:query", function(event)
 132         local origin, stanza = event.origin, event.stanza;
 133         origin.send(st.reply(stanza):query("http://jabber.org/protocol/disco#items"));
 134         return true;
 135 end, -1);
 136
 137 module:hook("iq-get/host/http://jabber.org/protocol/bytestreams:query", function(event)
 138         local origin, stanza = event.origin, event.stanza;
 139
 140         -- check ACL
 141         while proxy_acl and #proxy_acl > 0 do -- using 'while' instead of 'if' so we can break out of it
 142                 local jid = stanza.attr.from;
 143                 for _, acl in ipairs(proxy_acl) do
 144                         if jid_compare(jid, acl) then break; end
 145                 end
 146                 module:log("warn", "Denying use of proxy for %s", tostring(stanza.attr.from));
 147                 origin.send(st.error_reply(stanza, "auth", "forbidden"));
 148                 return true;
 149         end
 150
 151         local sid = stanza.tags[1].attr.sid;
 152         origin.send(st.reply(stanza):tag("query", {xmlns="http://jabber.org/protocol/bytestreams", sid=sid})
 153                 :tag("streamhost", {jid=host, host=proxy_address, port=proxy_port}));
 154         return true;
 155 end);
 156
 157 module.unload = function()
 158         connlisteners.deregister(module.host .. ':proxy65');
 159 end
 160
 161 local function set_activation(stanza)
 162         local to, reply;
 163         local from = stanza.attr.from;
 164         local query = stanza.tags[1];
 165         local sid = query.attr.sid;
 166         if query.tags[1] and query.tags[1].name == "activate" then
 167                 to = query.tags[1][1];
 168         end
 169         if from ~= nil and to ~= nil and sid ~= nil then
 170                 reply = st.iq({type="result", from=host, to=from});
 171                 reply.attr.id = stanza.attr.id;
 172         end
 173         return reply, from, to, sid;
 174 end
 175
 176 module:hook("iq-set/host/http://jabber.org/protocol/bytestreams:query", function(event)
 177         local origin, stanza = event.origin, event.stanza;
 178
 179         module:log("debug", "Received activation request from %s", stanza.attr.from);
 180         local reply, from, to, sid = set_activation(stanza);
 181         if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
 182                 local sha = sha1(sid .. from .. to, true);
 183                 if transfers[sha] == nil then
 184                         module:log("error", "transfers[sha]: nil");
 185                 elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
 186                         origin.send(reply);
 187                         transfers[sha].activated = true;
 188                         transfers[sha].target:lock_read(false);
 189                         transfers[sha].initiator:lock_read(false);
 190                 else
 191                         module:log("debug", "Both parties were not yet connected");
 192                         local message = "Neither party is connected to the proxy";
 193                         if transfers[sha].initiator then
 194                                 message = "The recipient is not connected to the proxy";
 195                         elseif transfers[sha].target then
 196                                 message = "The sender (you) is not connected to the proxy";
 197                         end
 198                         origin.send(st.error_reply(stanza, "cancel", "not-allowed", message));
 199                 end
 200                 return true;
 201         else
 202                 module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
 203         end
 204 end);
 205
 206 if not connlisteners.register(module.host .. ':proxy65', connlistener) then
 207         module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
 208         module:log("error", "Possibly two proxy65 components are configured to share the same port.");
 209 end
 210
 211 connlisteners.start(module.host .. ':proxy65');