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 = require "util.jid".split, require "util.jid".join;
  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
  24 local host, name = module:get_host(), "SOCKS5 Bytestreams Service";
  25 local sessions, transfers, component, replies_cache = {}, {}, nil, {};
  26
  27 local proxy_port = config_get(host, "core", "proxy65_port") or 5000;
  28 local proxy_interface = config_get(host, "core", "proxy65_interface") or "*";
  29 local proxy_address = config_get(host, "core", "proxy65_address") or (proxy_interface ~= "*" and proxy_interface) or host;
  30 local proxy_acl = config_get(host, "core", "proxy65_acl");
  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].initiator == conn and transfers[sha].target ~= nil then
  59                                 transfers[sha].target:write(data);
  60                                 return;
  61                         end
  62                 end
  63                 if data ~= nil and data:len() == 0x2F and  -- 40 == length of SHA1 HASH, and 7 other bytes => 47 => 0x2F
  64                         data:sub(1):byte() == 0x05 and -- SOCKS5 has 5 in first byte
  65                         data:sub(2):byte() == 0x01 and -- CMD must be 1
  66                         data:sub(3):byte() == 0x00 and -- RSV must be 0
  67                         data:sub(4):byte() == 0x03 and -- ATYP must be 3
  68                         data:sub(5):byte() == 40 and -- SHA1 HASH length must be 40 (0x28)
  69                         data:sub(-2):byte() == 0x00 and -- PORT must be 0, size 2 byte
  70                         data:sub(-1):byte() == 0x00
  71                 then
  72                         local sha = data:sub(6, 45); -- second param is not count! it's the ending index (included!)
  73                         if transfers[sha] == nil then
  74                                 transfers[sha] = {};
  75                                 transfers[sha].activated = false;
  76                                 transfers[sha].target = conn;
  77                                 session.sha = sha;
  78                                 module:log("debug", "target connected ... ");
  79                         elseif transfers[sha].target ~= nil then
  80                                 transfers[sha].initiator = conn;
  81                                 session.sha = sha;
  82                                 module:log("debug", "initiator connected ... ");
  83                                 throttle_sending(conn, transfers[sha].target);
  84                         end
  85                         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)
  86                 else
  87                         module:log("warn", "Neither data transfer nor initial connect of a participator of a transfer.")
  88                         conn.close();
  89                 end
  90         else
  91                 if data ~= nil then
  92                         module:log("warn", "unknown connection with no authentication data -> closing it");
  93                         conn.close();
  94                 end
  95         end
  96 end
  97
  98 function connlistener.ondisconnect(conn, err)
  99         local session = sessions[conn];
 100         if session then
 101                 if session.sha and transfers[session.sha] then
 102                         local initiator, target = transfers[session.sha].initiator, transfers[session.sha].target;
 103                         if initiator == conn and target ~= nil then
 104                                 target.close();
 105                         elseif target == conn and initiator ~= nil then
 106                                 initiator.close();
 107                         end
 108                         transfers[session.sha] = nil;
 109                 end
 110                 -- Clean up any session-related stuff here
 111                 sessions[conn] = nil;
 112         end
 113 end
 114
 115 local function get_disco_info(stanza)
 116         local reply = replies_cache.disco_info;
 117         if reply == nil then
 118                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#info")
 119                         :tag("identity", {category='proxy', type='bytestreams', name=name}):up()
 120                         :tag("feature", {var="http://jabber.org/protocol/bytestreams"});
 121                 replies_cache.disco_info = reply;
 122         end
 123
 124         reply.attr.id = stanza.attr.id;
 125         reply.attr.to = stanza.attr.from;
 126         return reply;
 127 end
 128
 129 local function get_disco_items(stanza)
 130         local reply = replies_cache.disco_items;
 131         if reply == nil then
 132                 reply = st.iq({type='result', from=host}):query("http://jabber.org/protocol/disco#items");
 133                 replies_cache.disco_items = reply;
 134         end
 135
 136         reply.attr.id = stanza.attr.id;
 137         reply.attr.to = stanza.attr.from;
 138         return reply;
 139 end
 140
 141 local function get_stream_host(origin, stanza)
 142         local reply = replies_cache.stream_host;
 143         local err_reply = replies_cache.stream_host_err;
 144         local sid = stanza.tags[1].attr.sid;
 145         local allow = false;
 146         local jid_node, jid_host, jid_resource = jid_split(stanza.attr.from);
 147
 148         if stanza.attr.from == nil then
 149                 jid_node = origin.username;
 150                 jid_host = origin.host;
 151                 jid_resource = origin.resource;
 152         end
 153
 154         if proxy_acl and #proxy_acl > 0 then
 155                 if host ~= nil then -- at least a domain is needed.
 156                         for _, acl in ipairs(proxy_acl) do
 157                                 local acl_node, acl_host, acl_resource = jid_split(acl);
 158                                 if ((acl_node ~= nil and acl_node == jid_node) or acl_node == nil) and
 159                                    ((acl_host ~= nil and acl_host == jid_host) or acl_host == nil) and
 160                                    ((acl_resource ~= nil and acl_resource == jid_resource) or acl_resource == nil) then
 161                                         allow = true;
 162                                 end
 163                         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_join(jid_node, jid_host, jid_resource)));
 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         return reply;
 190 end
 191
 192 module.unload = function()
 193         componentmanager.deregister_component(host);
 194         connlisteners.deregister(module.host .. ':proxy65');
 195 end
 196
 197 local function set_activation(stanza)
 198         local from, to, sid, reply = nil;
 199         from = stanza.attr.from;
 200         if stanza.tags[1] ~= nil and tostring(stanza.tags[1].name) == "query" then
 201                 if stanza.tags[1].attr ~= nil then
 202                         sid = stanza.tags[1].attr.sid;
 203                 end
 204                 if stanza.tags[1].tags[1] ~= nil and tostring(stanza.tags[1].tags[1].name) == "activate" then
 205                         to = stanza.tags[1].tags[1][1];
 206                 end
 207         end
 208         if from ~= nil and to ~= nil and sid ~= nil then
 209                 reply = st.iq({type="result", from=host, to=from});
 210                 reply.attr.id = stanza.attr.id;
 211         end
 212         return reply, from, to, sid;
 213 end
 214
 215 function handle_to_domain(origin, stanza)
 216         local to_node, to_host, to_resource = jid_split(stanza.attr.to);
 217         if to_node == nil then
 218                 local type = stanza.attr.type;
 219                 if type == "error" or type == "result" then return; end
 220                 if stanza.name == "iq" and type == "get" then
 221                         local xmlns = stanza.tags[1].attr.xmlns
 222                         if xmlns == "http://jabber.org/protocol/disco#info" then
 223                                 origin.send(get_disco_info(stanza));
 224                                 return true;
 225                         elseif xmlns == "http://jabber.org/protocol/disco#items" then
 226                                 origin.send(get_disco_items(stanza));
 227                                 return true;
 228                         elseif xmlns == "http://jabber.org/protocol/bytestreams" then
 229                                 origin.send(get_stream_host(origin, stanza));
 230                                 return true;
 231                         end
 232                 elseif stanza.name == "iq" and type == "set" then
 233                         local reply, from, to, sid = set_activation(stanza);
 234                         if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
 235                                 local sha = sha1(sid .. from .. to, true);
 236                                 if transfers[sha] == nil then
 237                                         module:log("error", "transfers[sha]: nil");
 238                                 elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
 239                                         origin.send(reply);
 240                                         transfers[sha].activated = true;
 241                                 end
 242                         else
 243                                 module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
 244                         end
 245                 end
 246         end
 247         return;
 248 end
 249
 250 if not connlisteners.register(module.host .. ':proxy65', connlistener) then
 251         module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
 252         module:log("error", "Possibly two proxy65 components are configured to share the same port.");
 253 end
 254
 255 connlisteners.start(module.host .. ':proxy65');
 256 component = componentmanager.register_component(host, handle_to_domain);
 257 local sender_lock_threshold = 1024;
 258 function throttle_sending(sender, receiver)
 259         sender:pattern(sender_lock_threshold);
 260         local sender_locked;
 261         local _sendbuffer = receiver.sendbuffer;
 262         function receiver.sendbuffer()
 263                 _sendbuffer();
 264                 if sender_locked and receiver.bufferlen() < sender_lock_threshold then
 265                         sender:lock(false); -- Unlock now
 266                         sender_locked = nil;
 267                 end
 268         end
 269
 270         local _readbuffer = sender.readbuffer;
 271         function sender.readbuffer()
 272                 _readbuffer();
 273                 if not sender_locked and receiver.bufferlen() >= sender_lock_threshold then
 274                         sender_locked = true;
 275                         sender:lock(true);
 276                 end
 277         end
 278 end