SIP support

Conflicts:
	configure
	configure.ac
	doc/guide.tex

1 files changed, 404 insertions, 0 deletions

diff --git a/src/mod_sip.erl b/src/mod_sip.erl
new file mode 100644
index 00000000..cca91a33
--- /dev/null
+++ b/src/mod_sip.erl
@@ -0,0 +1,404 @@
+%%%-------------------------------------------------------------------
+%%% @author Evgeny Khramtsov <ekhramtsov@process-one.net>
+%%% @copyright (C) 2014, Evgeny Khramtsov
+%%% @doc
+%%%
+%%% @end
+%%% Created : 21 Apr 2014 by Evgeny Khramtsov <ekhramtsov@process-one.net>
+%%%-------------------------------------------------------------------
+-module(mod_sip).
+
+-behaviour(gen_mod).
+-behaviour(esip).
+
+%% API
+-export([start/2, stop/1, prepare_request/1, make_response/2,
+	 add_certfile/2, add_via/3]).
+
+%% esip_callbacks
+-export([data_in/2, data_out/2, message_in/2, message_out/2,
+	 request/2, request/3, response/2, locate/1]).
+
+-include("ejabberd.hrl").
+-include("logger.hrl").
+-include("esip.hrl").
+
+-record(sip_session, {us = {<<"">>, <<"">>} :: {binary(), binary()},
+		      socket = #sip_socket{},
+		      timestamp = now() :: erlang:timestamp(),
+		      tref = make_ref() :: reference(),
+		      expires = 0 :: non_neg_integer()}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+start(_Host, _Opts) ->
+    ejabberd:start_app(esip),
+    esip:set_config_value(max_server_transactions, 10000),
+    esip:set_config_value(max_client_transactions, 10000),
+    esip:set_config_value(software, <<"ejabberd ", (?VERSION)/binary>>),
+    esip:set_config_value(module, ?MODULE),
+    Spec = {mod_sip_registrar, {mod_sip_registrar, start_link, []},
+	    transient, 2000, worker, [mod_sip_registrar]},
+    TmpSupSpec = {mod_sip_proxy_sup,
+		  {ejabberd_tmp_sup, start_link,
+		   [mod_sip_proxy_sup, mod_sip_proxy]},
+		  permanent, infinity, supervisor, [ejabberd_tmp_sup]},
+    supervisor:start_child(ejabberd_sup, Spec),
+    supervisor:start_child(ejabberd_sup, TmpSupSpec),
+    ok.
+
+stop(_Host) ->
+    ok.
+
+data_in(Data, #sip_socket{type = Transport,
+                          addr = {MyIP, MyPort},
+                          peer = {PeerIP, PeerPort}}) ->
+    ?DEBUG(
+       "SIP [~p/in] ~s:~p -> ~s:~p:~n~s",
+       [Transport, inet_parse:ntoa(PeerIP), PeerPort,
+	inet_parse:ntoa(MyIP), MyPort, Data]).
+
+data_out(Data, #sip_socket{type = Transport,
+                           addr = {MyIP, MyPort},
+                           peer = {PeerIP, PeerPort}}) ->
+    ?DEBUG(
+       "SIP [~p/out] ~s:~p -> ~s:~p:~n~s",
+       [Transport, inet_parse:ntoa(MyIP), MyPort,
+	inet_parse:ntoa(PeerIP), PeerPort, Data]).
+
+message_in(#sip{type = request, method = M} = Req, SIPSock)
+  when M /= <<"ACK">>, M /= <<"CANCEL">> ->
+    case action(Req, SIPSock) of
+        {relay, _LServer, _Opts} ->
+            ok;
+        Action ->
+            request(Req, SIPSock, undefined, Action)
+    end;
+message_in(_, _) ->
+    ok.
+
+message_out(_, _) ->
+    ok.
+
+response(Resp, SIPSock) ->
+    case action(Resp, SIPSock) of
+        {relay, LServer, Opts} ->
+            case esip:split_hdrs('via', Resp#sip.hdrs) of
+                {[_], _} ->
+                    ok;
+                {[_MyVia|Vias], TailHdrs} ->
+		    %% TODO: check if MyVia is really my Via
+		    NewResp = Resp#sip{hdrs = [{'via', Vias}|TailHdrs]},
+		    case proplists:get_value(socket, Opts) of
+			undefined ->
+			    case esip:connect(NewResp,
+					      add_certfile(LServer, Opts)) of
+				{ok, SIPSockOut} ->
+				    esip:send(SIPSockOut, NewResp);
+				{error, _} ->
+				    ok
+			    end;
+			SIPSockOut ->
+			    esip:send(SIPSockOut, NewResp)
+		    end
+            end;
+        _ ->
+            ok
+    end.
+
+request(#sip{method = <<"ACK">>} = Req, SIPSock) ->
+    case action(Req, SIPSock) of
+        {relay, LServer, Opts} ->
+	    Req1 = prepare_request(Req),
+	    case esip:connect(Req1, add_certfile(LServer, Opts)) of
+		{ok, SIPSockOut} ->
+		    Req2 = add_via(SIPSockOut, LServer, Req1),
+		    esip:send(SIPSockOut, Req2);
+		{error, _} = Err ->
+		    Err
+	    end;
+        _ ->
+            pass
+    end;
+request(#sip{method = <<"CANCEL">>} = Req, SIPSock) ->
+    case action(Req, SIPSock) of
+        loop ->
+            make_response(Req, #sip{status = 483, type = response});
+        {unsupported, Require} ->
+            make_response(Req, #sip{status = 420,
+                                    type = response,
+                                    hdrs = [{'unsupported',
+                                             Require}]});
+        {relay, LServer, Opts} ->
+	    Req1 = prepare_request(Req),
+	    case esip:connect(Req1, add_certfile(LServer, Opts)) of
+		{ok, SIPSockOut} ->
+		    Req2 = add_via(SIPSockOut, LServer, Req1),
+		    esip:send(SIPSockOut, Req2);
+		{error, _} = Err ->
+		    Err
+	    end,
+            pass;
+        _ ->
+            pass
+    end.
+
+request(Req, SIPSock, TrID) ->
+    request(Req, SIPSock, TrID, action(Req, SIPSock)).
+
+request(Req, SIPSock, TrID, Action) ->
+    case Action of
+        to_me ->
+            process(Req, SIPSock);
+        register ->
+            mod_sip_registrar:request(Req, SIPSock);
+        loop ->
+            make_response(Req, #sip{status = 483, type = response});
+        {unsupported, Require} ->
+            make_response(Req, #sip{status = 420,
+                                    type = response,
+                                    hdrs = [{'unsupported',
+                                             Require}]});
+        {relay, LServer, Opts} ->
+            case mod_sip_proxy:start(LServer, Opts) of
+                {ok, Pid} ->
+                    mod_sip_proxy:route(Req, SIPSock, TrID, Pid),
+                    {mod_sip_proxy, route, [Pid]};
+                Err ->
+		    ?INFO_MSG("failed to proxy request ~p: ~p", [Req, Err]),
+                    Err
+            end;
+        {proxy_auth, Host} ->
+            make_response(
+              Req,
+              #sip{status = 407,
+                   type = response,
+                   hdrs = [{'proxy-authenticate',
+                            make_auth_hdr(Host)}]});
+        {auth, Host} ->
+            make_response(
+              Req,
+              #sip{status = 401,
+                   type = response,
+                   hdrs = [{'www-authenticate',
+                            make_auth_hdr(Host)}]});
+        deny ->
+            make_response(Req, #sip{status = 403,
+                                    type = response});
+        not_found ->
+            make_response(Req, #sip{status = 480,
+                                    type = response})
+    end.
+
+locate(_SIPMsg) ->
+    ok.
+
+find(#uri{user = User, host = Host}) ->
+    LUser = jlib:nodeprep(User),
+    LServer = jlib:nameprep(Host),
+    case mod_sip_registrar:find_session(
+	   LUser, LServer) of
+	{ok, #sip_session{socket = Sock}} ->
+	    {relay, LServer, [{socket, Sock}]};
+	error ->
+	    not_found
+    end.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+action(#sip{type = response, hdrs = Hdrs}, _SIPSock) ->
+    {_, ToURI, _} = esip:get_hdr('to', Hdrs),
+    {_, FromURI, _} = esip:get_hdr('from', Hdrs),
+    case at_my_host(FromURI) of
+	true ->
+	    case at_my_host(ToURI) of
+		true ->
+		    find(ToURI);
+		false ->
+		    LServer = jlib:nameprep(FromURI#uri.host),
+		    {relay, LServer, []}
+	    end;
+	false ->
+	    case at_my_host(ToURI) of
+		true ->
+		    find(ToURI);
+		false ->
+		    pass
+	    end
+    end;
+action(#sip{method = <<"REGISTER">>, type = request, hdrs = Hdrs,
+            uri = #uri{user = <<"">>} = URI} = Req, SIPSock) ->
+    case at_my_host(URI) of
+	true ->
+	    case esip:get_hdrs('require', Hdrs) of
+		[_|_] = Require ->
+		    {unsupported, Require};
+		_ ->
+		    {_, ToURI, _} = esip:get_hdr('to', Hdrs),
+		    case at_my_host(ToURI) of
+			true ->
+			    case check_auth(Req, 'authorization', SIPSock) of
+				true ->
+				    register;
+				false ->
+				    {auth, ToURI#uri.host}
+			    end;
+			false ->
+			    deny
+		    end
+	    end;
+	false ->
+	    deny
+    end;
+action(#sip{method = Method, hdrs = Hdrs, type = request} = Req, SIPSock) ->
+    case esip:get_hdr('max-forwards', Hdrs) of
+        0 when Method == <<"OPTIONS">> ->
+            to_me;
+        0 ->
+            loop;
+        _ ->
+            case esip:get_hdrs('proxy-require', Hdrs) of
+                [_|_] = Require ->
+                    {unsupported, Require};
+                _ ->
+                    {_, ToURI, _} = esip:get_hdr('to', Hdrs),
+                    {_, FromURI, _} = esip:get_hdr('from', Hdrs),
+		    case at_my_host(FromURI) of
+			true ->
+			    case check_auth(Req, 'proxy-authorization', SIPSock) of
+                                true ->
+				    case at_my_host(ToURI) of
+					true ->
+					    find(ToURI);
+					false ->
+					    LServer = jlib:nameprep(FromURI#uri.host),
+					    {relay, LServer, []}
+				    end;
+                                false ->
+                                    {proxy_auth, FromURI#uri.host}
+                            end;
+			false ->
+			    case at_my_host(ToURI) of
+				true ->
+				    find(ToURI);
+				false ->
+				    deny
+			    end
+                    end
+            end
+    end.
+
+check_auth(#sip{method = <<"CANCEL">>}, _, _SIPSock) ->
+    true;
+check_auth(#sip{method = Method, hdrs = Hdrs, body = Body}, AuthHdr, _SIPSock) ->
+    
+    Issuer = case AuthHdr of
+                 'authorization' ->
+                     to;
+                 'proxy-authorization' ->
+                     from
+             end,
+    {_, #uri{user = User, host = Host}, _} = esip:get_hdr(Issuer, Hdrs),
+    LUser = jlib:nodeprep(User),
+    LServer = jlib:nameprep(Host),
+    case lists:filter(
+           fun({_, Params}) ->
+                   Username = esip:get_param(<<"username">>, Params),
+                   Realm = esip:get_param(<<"realm">>, Params),
+                   (LUser == esip:unquote(Username))
+                       and (LServer == esip:unquote(Realm))
+           end, esip:get_hdrs(AuthHdr, Hdrs)) of
+        [Auth|_] ->
+	    case ejabberd_auth:get_password_s(LUser, LServer) of
+		<<"">> ->
+		    false;
+		Password ->
+		    esip:check_auth(Auth, Method, Body, Password)
+	    end;
+        [] ->
+            false
+    end.
+
+allow() ->
+    [<<"OPTIONS">>, <<"REGISTER">>].
+
+process(#sip{method = <<"OPTIONS">>} = Req, _) ->
+    make_response(Req, #sip{type = response, status = 200,
+                            hdrs = [{'allow', allow()}]});
+process(#sip{method = <<"REGISTER">>} = Req, _) ->
+    make_response(Req, #sip{type = response, status = 400});
+process(Req, _) ->
+    make_response(Req, #sip{type = response, status = 405,
+			    hdrs = [{'allow', allow()}]}).
+
+prepare_request(#sip{hdrs = Hdrs1} = Req) ->
+    MF = esip:get_hdr('max-forwards', Hdrs1),
+    Hdrs2 = esip:set_hdr('max-forwards', MF-1, Hdrs1),
+    Hdrs3 = lists:filter(
+              fun({'proxy-authorization', {_, Params}}) ->
+                      Realm = esip:unquote(esip:get_param(<<"realm">>, Params)),
+		      not is_my_host(jlib:nameprep(Realm));
+                 (_) ->
+                      true
+              end, Hdrs2),
+    Req#sip{hdrs = Hdrs3}.
+
+make_auth_hdr(LServer) ->
+    Realm = jlib:nameprep(LServer),
+    {<<"Digest">>, [{<<"realm">>, esip:quote(Realm)},
+                    {<<"qop">>, esip:quote(<<"auth">>)},
+                    {<<"nonce">>, esip:quote(esip:make_hexstr(20))}]}.
+
+make_response(Req, Resp) ->
+    esip:make_response(Req, Resp, esip:make_tag()).
+
+at_my_host(#uri{host = Host}) ->
+    is_my_host(jlib:nameprep(Host)).
+
+is_my_host(LServer) ->
+    gen_mod:is_loaded(LServer, ?MODULE).
+
+add_certfile(LServer, Opts) ->
+    case ejabberd_config:get_option({domain_certfile, LServer},
+				    fun iolist_to_binary/1) of
+	CertFile when is_binary(CertFile), CertFile /= <<"">> ->
+	    [{certfile, CertFile}|Opts];
+	_ ->
+	    Opts
+    end.
+
+add_via(#sip_socket{type = Transport}, LServer, #sip{hdrs = Hdrs} = Req) ->
+    ConfiguredVias = get_configured_vias(LServer),
+    {ViaHost, ViaPort} = proplists:get_value(
+			   Transport, ConfiguredVias, {LServer, undefined}),
+    ViaTransport = case Transport of
+		       tls -> <<"TLS">>;
+		       tcp -> <<"TCP">>;
+		       udp -> <<"UDP">>
+		   end,
+    Via = #via{transport = ViaTransport,
+	       host = ViaHost,
+	       port = ViaPort,
+	       params = [{<<"branch">>, esip:make_branch()},
+			 {<<"rport">>, <<"">>}]},
+    Req#sip{hdrs = [{'via', [Via]}|Hdrs]}.
+
+get_configured_vias(LServer) ->
+    gen_mod:get_module_opt(
+      LServer, ?MODULE, via,
+      fun(L) ->
+	      lists:map(
+		fun(Opts) ->
+			Type = proplists:get_value(type, Opts),
+			Host = proplists:get_value(host, Opts),
+			Port = proplists:get_value(port, Opts),
+			true = (Type == tcp) or (Type == tls) or (Type == udp),
+			true = is_binary(Host) and (Host /= <<"">>),
+			true = (is_integer(Port)
+				and (Port > 0) and (Port < 65536))
+			    or (Port == undefined),
+			{Type, {Host, Port}}
+		end, L)
+      end, []).