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 componentmanager = require "core.componentmanager";
  20 local config_get = require "core.configmanager".get;
  21 local connlisteners = require "net.connlisteners";
  22 local sha1 = require "util.hashes".sha1;
  23 local server = require "net.server";
  24
  25 local host, name = module:get_host(), "SOCKS5 Bytestreams Service";
  26 local sessions, transfers, component, replies_cache = {}, {}, nil, {};
  27
  28 local proxy_port = config_get(host, "core", "proxy65_port") or 5000;
  29 local proxy_interface = config_get(host, "core", "proxy65_interface") or "*";
  30 local proxy_address = config_get(host, "core", "proxy65_address") or (proxy_interface ~= "*" and proxy_interface) or host;
  31 local proxy_acl = config_get(host, "core", "proxy65_acl");
  32 local max_buffer_size = 4096;
  33
  34 local connlistener = { default_port = proxy_port, default_interface = proxy_interface, default_mode = "*a" };
  35
  36 function connlistener.onincoming(conn, data)
  37         local session = sessions[conn] or {};
  38
  39         if session.setup == nil and data ~= nil and data:sub(1):byte() == 0x05 and data:len() > 2 then
  40                 local nmethods = data:sub(2):byte();
  41                 local methods = data:sub(3);
  42                 local supported = false;
  43                 for i=1, nmethods, 1 do
  44                         if(methods:sub(i):byte() == 0x00) then -- 0x00 == method: NO AUTH
  45                                 supported = true;
  46                                 break;
  47                         end
  48                 end
  49                 if(supported) then
  50                         module:log("debug", "new session found ... ")
  51                         session.setup = true;
  52                         sessions[conn] = session;
  53                         conn:write(string.char(5, 0));
  54                 end
  55                 return;
  56         end
  57         if session.setup then
  58                 if session.sha ~= nil and transfers[session.sha] ~= nil then
  59                         local sha = session.sha;
  60                         if transfers[sha].activated == true and transfers[sha].target ~= nil then
  61                                 if  transfers[sha].initiator == conn then
  62                                         transfers[sha].target:write(data);
  63                                 else
  64                                         transfers[sha].initiator:write(data);
  65                                 end
  66                                 return;
  67                         end
  68                 end
  69                 if data ~= nil and data:len() == 0x2F and  -- 40 == length of SHA1 HASH, and 7 other bytes => 47 => 0x2F
  70                         data:sub(1):byte() == 0x05 and -- SOCKS5 has 5 in first byte
  71                         data:sub(2):byte() == 0x01 and -- CMD must be 1
  72                         data:sub(3):byte() == 0x00 and -- RSV must be 0
  73                         data:sub(4):byte() == 0x03 and -- ATYP must be 3
  74                         data:sub(5):byte() == 40 and -- SHA1 HASH length must be 40 (0x28)
  75                         data:sub(-2):byte() == 0x00 and -- PORT must be 0, size 2 byte
  76                         data:sub(-1):byte() == 0x00
  77                 then
  78                         local sha = data:sub(6, 45); -- second param is not count! it's the ending index (included!)
  79                         if transfers[sha] == nil then
  80                                 transfers[sha] = {};
  81                                 transfers[sha].activated = false;
  82                                 transfers[sha].target = conn;
  83                                 session.sha = sha;
  84                                 module:log("debug", "target connected ... ");
  85                         elseif transfers[sha].target ~= nil then
  86                                 transfers[sha].initiator = conn;
  87                                 session.sha = sha;
  88                                 module:log("debug", "initiator connected ... ");
  89                                 server.link(conn, transfers[sha].target, max_buffer_size);
  90                                 server.link(transfers[sha].target, conn, max_buffer_size);
  91                         end
  92                         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)
  93                         conn:lock_read(true)
  94                 else
  95                         module:log("warn", "Neither data transfer nor initial connect of a participator of a transfer.")
  96                         conn:close();
  97                 end
  98         else
  99                 if data ~= nil then
 100                         module:log("warn", "unknown connection with no authentication data -> closing it");
 101                         conn:close();
 102                 end
 103         end
 104 end
 105
 106 function connlistener.ondisconnect(conn, err)
 107         local session = sessions[conn];
 108         if session then
 109                 if session.sha and transfers[session.sha] then
 110                         local initiator, target = transfers[session.sha].initiator, transfers[session.sha].target;
 111                         if initiator == conn and target ~= nil then
 112                                 target:close();
 113                         elseif target == conn and initiator ~= nil then
 114                                 initiator:close();
 115                         end
 116                         transfers[session.sha] = nil;
 117                 end
 118                 -- Clean up any session-related stuff here
 119                 sessions[conn] = nil;
 120         end
 121 end
 122
 123 local function get_disco_info(stanza)
 124         local reply = replies_cache.disco_info;
 125         if reply == nil then
 126                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#info")
 127                         :tag("identity", {category='proxy', type='bytestreams', name=name}):up()
 128                         :tag("feature", {var="http://jabber.org/protocol/bytestreams"});
 129                 replies_cache.disco_info = reply;
 130         end
 131
 132         reply.attr.id = stanza.attr.id;
 133         reply.attr.to = stanza.attr.from;
 134         return reply;
 135 end
 136
 137 local function get_disco_items(stanza)
 138         local reply = replies_cache.disco_items;
 139         if reply == nil then
 140                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#items");
 141                 replies_cache.disco_items = reply;
 142         end
 143
 144         reply.attr.id = stanza.attr.id;
 145         reply.attr.to = stanza.attr.from;
 146         return reply;
 147 end
 148
 149 local function get_stream_host(origin, stanza)
 150         local reply = replies_cache.stream_host;
 151         local err_reply = replies_cache.stream_host_err;
 152         local sid = stanza.tags[1].attr.sid;
 153         local allow = false;
 154         local jid = stanza.attr.from;
 155
 156         if proxy_acl and #proxy_acl > 0 then
 157                 for _, acl in ipairs(proxy_acl) do
 158                         if jid_compare(jid, acl) then allow = true; end
 159                 end
 160         else
 161                 allow = true;
 162         end
 163         if allow == true then
 164                 if reply == nil then
 165                         reply = st.iq({type="result", from=host})
 166                                 :query("http://jabber.org/protocol/bytestreams")
 167                                 :tag("streamhost", {jid=host, host=proxy_address, port=proxy_port});
 168                         replies_cache.stream_host = reply;
 169                 end
 170         else
 171                 module:log("warn", "Denying use of proxy for %s", tostring(jid));
 172                 if err_reply == nil then
 173                         err_reply = st.iq({type="error", from=host})
 174                                 :query("http://jabber.org/protocol/bytestreams")
 175                                 :tag("error", {code='403', type='auth'})
 176                                 :tag("forbidden", {xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'});
 177                         replies_cache.stream_host_err = err_reply;
 178                 end
 179                 reply = err_reply;
 180         end
 181         reply.attr.id = stanza.attr.id;
 182         reply.attr.to = stanza.attr.from;
 183         reply.tags[1].attr.sid = sid;
 184         return reply;
 185 end
 186
 187 module.unload = function()
 188         componentmanager.deregister_component(host);
 189         connlisteners.deregister(module.host .. ':proxy65');
 190 end
 191
 192 local function set_activation(stanza)
 193         local from, to, sid, reply = nil;
 194         from = stanza.attr.from;
 195         if stanza.tags[1] ~= nil and tostring(stanza.tags[1].name) == "query" then
 196                 if stanza.tags[1].attr ~= nil then
 197                         sid = stanza.tags[1].attr.sid;
 198                 end
 199                 if stanza.tags[1].tags[1] ~= nil and tostring(stanza.tags[1].tags[1].name) == "activate" then
 200                         to = stanza.tags[1].tags[1][1];
 201                 end
 202         end
 203         if from ~= nil and to ~= nil and sid ~= nil then
 204                 reply = st.iq({type="result", from=host, to=from});
 205                 reply.attr.id = stanza.attr.id;
 206         end
 207         return reply, from, to, sid;
 208 end
 209
 210 function handle_to_domain(origin, stanza)
 211         local to_node, to_host, to_resource = jid_split(stanza.attr.to);
 212         if to_node == nil then
 213                 local type = stanza.attr.type;
 214                 if type == "error" or type == "result" then return; end
 215                 if stanza.name == "iq" and type == "get" then
 216                         local xmlns = stanza.tags[1].attr.xmlns
 217                         if xmlns == "http://jabber.org/protocol/disco#info" then
 218                                 origin.send(get_disco_info(stanza));
 219                                 return true;
 220                         elseif xmlns == "http://jabber.org/protocol/disco#items" then
 221                                 origin.send(get_disco_items(stanza));
 222                                 return true;
 223                         elseif xmlns == "http://jabber.org/protocol/bytestreams" then
 224                                 origin.send(get_stream_host(origin, stanza));
 225                                 return true;
 226                         else
 227                                 origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
 228                                 return true;
 229                         end
 230                 elseif stanza.name == "iq" and type == "set" then
 231                         module:log("debug", "Received activation request from %s", stanza.attr.from);
 232                         local reply, from, to, sid = set_activation(stanza);
 233                         if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
 234                                 local sha = sha1(sid .. from .. to, true);
 235                                 if transfers[sha] == nil then
 236                                         module:log("error", "transfers[sha]: nil");
 237                                 elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
 238                                         origin.send(reply);
 239                                         transfers[sha].activated = true;
 240                                         transfers[sha].target:lock_read(false);
 241                                         transfers[sha].initiator:lock_read(false);
 242                                 else
 243                                         module:log("debug", "Both parties were not yet connected");
 244                                         local message = "Neither party is connected to the proxy";
 245                                         if transfers[sha].initiator then
 246                                                 message = "The recipient is not connected to the proxy";
 247                                         elseif transfers[sha].target then
 248                                                 message = "The sender (you) is not connected to the proxy";
 249                                         end
 250                                         origin.send(st.error_reply(stanza, "cancel", "not-allowed", message));
 251                                 end
 252                         else
 253                                 module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
 254                         end
 255                 end
 256         end
 257         return;
 258 end
 259
 260 if not connlisteners.register(module.host .. ':proxy65', connlistener) then
 261         module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
 262         module:log("error", "Possibly two proxy65 components are configured to share the same port.");
 263 end
 264
 265 connlisteners.start(module.host .. ':proxy65');
 266 component = componentmanager.register_component(host, handle_to_domain);