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].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                                 throttle_sending(conn, transfers[sha].target);
  88                                 throttle_sending(transfers[sha].target, conn);
  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_node, jid_host, jid_resource = jid_split(stanza.attr.from);
 153
 154         if stanza.attr.from == nil then
 155                 jid_node = origin.username;
 156                 jid_host = origin.host;
 157                 jid_resource = origin.resource;
 158         end
 159
 160         if proxy_acl and #proxy_acl > 0 then
 161                 if host ~= nil then -- at least a domain is needed.
 162                         for _, acl in ipairs(proxy_acl) do
 163                                 local acl_node, acl_host, acl_resource = jid_split(acl);
 164                                 if ((acl_node ~= nil and acl_node == jid_node) or acl_node == nil) and
 165                                    ((acl_host ~= nil and acl_host == jid_host) or acl_host == nil) and
 166                                    ((acl_resource ~= nil and acl_resource == jid_resource) or acl_resource == nil) then
 167                                         allow = true;
 168                                 end
 169                         end
 170                 end
 171         else
 172                 allow = true;
 173         end
 174         if allow == true then
 175                 if reply == nil then
 176                         reply = st.iq({type="result", from=host})
 177                                 :query("http://jabber.org/protocol/bytestreams")
 178                                 :tag("streamhost", {jid=host, host=proxy_address, port=proxy_port});
 179                         replies_cache.stream_host = reply;
 180                 end
 181         else
 182                 module:log("warn", "Denying use of proxy for %s", tostring(jid_join(jid_node, jid_host, jid_resource)));
 183                 if err_reply == nil then
 184                         err_reply = st.iq({type="error", from=host})
 185                                 :query("http://jabber.org/protocol/bytestreams")
 186                                 :tag("error", {code='403', type='auth'})
 187                                 :tag("forbidden", {xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'});
 188                         replies_cache.stream_host_err = err_reply;
 189                 end
 190                 reply = err_reply;
 191         end
 192         reply.attr.id = stanza.attr.id;
 193         reply.attr.to = stanza.attr.from;
 194         reply.tags[1].attr.sid = sid;
 195         return reply;
 196 end
 197
 198 module.unload = function()
 199         componentmanager.deregister_component(host);
 200         connlisteners.deregister(module.host .. ':proxy65');
 201 end
 202
 203 local function set_activation(stanza)
 204         local from, to, sid, reply = nil;
 205         from = stanza.attr.from;
 206         if stanza.tags[1] ~= nil and tostring(stanza.tags[1].name) == "query" then
 207                 if stanza.tags[1].attr ~= nil then
 208                         sid = stanza.tags[1].attr.sid;
 209                 end
 210                 if stanza.tags[1].tags[1] ~= nil and tostring(stanza.tags[1].tags[1].name) == "activate" then
 211                         to = stanza.tags[1].tags[1][1];
 212                 end
 213         end
 214         if from ~= nil and to ~= nil and sid ~= nil then
 215                 reply = st.iq({type="result", from=host, to=from});
 216                 reply.attr.id = stanza.attr.id;
 217         end
 218         return reply, from, to, sid;
 219 end
 220
 221 function handle_to_domain(origin, stanza)
 222         local to_node, to_host, to_resource = jid_split(stanza.attr.to);
 223         if to_node == nil then
 224                 local type = stanza.attr.type;
 225                 if type == "error" or type == "result" then return; end
 226                 if stanza.name == "iq" and type == "get" then
 227                         local xmlns = stanza.tags[1].attr.xmlns
 228                         if xmlns == "http://jabber.org/protocol/disco#info" then
 229                                 origin.send(get_disco_info(stanza));
 230                                 return true;
 231                         elseif xmlns == "http://jabber.org/protocol/disco#items" then
 232                                 origin.send(get_disco_items(stanza));
 233                                 return true;
 234                         elseif xmlns == "http://jabber.org/protocol/bytestreams" then
 235                                 origin.send(get_stream_host(origin, stanza));
 236                                 return true;
 237                         end
 238                 elseif stanza.name == "iq" and type == "set" then
 239                         local reply, from, to, sid = set_activation(stanza);
 240                         if reply ~= nil and from ~= nil and to ~= nil and sid ~= nil then
 241                                 local sha = sha1(sid .. from .. to, true);
 242                                 if transfers[sha] == nil then
 243                                         module:log("error", "transfers[sha]: nil");
 244                                 elseif(transfers[sha] ~= nil and transfers[sha].initiator ~= nil and transfers[sha].target ~= nil) then
 245                                         origin.send(reply);
 246                                         transfers[sha].activated = true;
 247                                         transfers[sha].target:lock_read(false);
 248                                         transfers[sha].initiator:lock_read(false);
 249                                 end
 250                         else
 251                                 module:log("error", "activation failed: sid: %s, initiator: %s, target: %s", tostring(sid), tostring(from), tostring(to));
 252                         end
 253                 end
 254         end
 255         return;
 256 end
 257
 258 if not connlisteners.register(module.host .. ':proxy65', connlistener) then
 259         module:log("error", "mod_proxy65: Could not establish a connection listener. Check your configuration please.");
 260         module:log("error", "Possibly two proxy65 components are configured to share the same port.");
 261 end
 262
 263 connlisteners.start(module.host .. ':proxy65');
 264 component = componentmanager.register_component(host, handle_to_domain);
 265 local sender_lock_threshold = 4096;
 266 function throttle_sending(sender, receiver)
 267         sender:pattern(sender_lock_threshold);
 268         local sender_locked;
 269         local _sendbuffer = receiver.sendbuffer;
 270         function receiver.sendbuffer()
 271                 _sendbuffer();
 272                 if sender_locked and receiver.bufferlen() < sender_lock_threshold then
 273                         sender:lock_read(false); -- Unlock now
 274                         sender_locked = nil;
 275                 end
 276         end
 277
 278         local _readbuffer = sender.readbuffer;
 279         function sender.readbuffer()
 280                 _readbuffer();
 281                 if not sender_locked and receiver.bufferlen() >= sender_lock_threshold then
 282                         sender_locked = true;
 283                         sender:lock_read(true);
 284                 end
 285         end
 286 end