1 files changed, 152 insertions, 0 deletions
diff --git a/src/mod_sip_proxy.erl b/src/mod_sip_proxy.erl
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+%%%-------------------------------------------------------------------
+%%% @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_proxy).
+
+-define(GEN_FSM, p1_fsm).
+-behaviour(?GEN_FSM).
+
+%% API
+-export([start/2, start_link/2, route/4, route/5]).
+
+%% gen_fsm callbacks
+-export([init/1, wait_for_request/2, wait_for_response/2,
+	 handle_event/3, handle_sync_event/4,
+	 handle_info/3, terminate/3, code_change/4]).
+
+-include("ejabberd.hrl").
+-include("logger.hrl").
+-include("esip.hrl").
+
+-define(MAX_REDIRECTS, 5).
+
+-record(state, {host = <<"">> :: binary(),
+		opts = []     :: [{certfile, binary()}],
+		orig_trid,
+		orig_req      :: #sip{},
+		client_trid}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+start(LServer, Opts) ->
+    supervisor:start_child(mod_sip_proxy_sup, [LServer, Opts]).
+
+start_link(LServer, Opts) ->
+    ?GEN_FSM:start_link(?MODULE, [LServer, Opts], []).
+
+route(Resp, Req, _SIPSock, TrID, Pid) ->
+    ?GEN_FSM:send_event(Pid, {Resp, Req, TrID}).
+
+route(SIPMsg, _SIPSock, TrID, Pid) ->
+    ?GEN_FSM:send_event(Pid, {SIPMsg, TrID}),
+    wait.
+
+%%%===================================================================
+%%% gen_fsm callbacks
+%%%===================================================================
+init([Host, Opts]) ->
+    {ok, wait_for_request, #state{opts = Opts, host = Host}}.
+
+wait_for_request({#sip{type = request} = Req, TrID}, State) ->
+    Opts = mod_sip:add_certfile(State#state.host, State#state.opts),
+    Req1 = mod_sip:prepare_request(Req),
+    case connect(Req1, Opts) of
+	{ok, SIPSocket} ->
+	    Req2 = mod_sip:add_via(SIPSocket, State#state.host, Req1),
+	    case esip:request(SIPSocket, Req2, {?MODULE, route, [self()]}) of
+		{ok, ClientTrID} ->
+		    {next_state, wait_for_response,
+		     State#state{orig_trid = TrID,
+				 orig_req = Req,
+				 client_trid = ClientTrID}};
+		Err ->
+		    {Status, Reason} = esip:error_status(Err),
+		    esip:reply(TrID, mod_sip:make_response(
+				       Req, #sip{type = response,
+						 status = Status,
+						 reason = Reason})),
+		    {stop, normal, State}
+	    end;
+	Err ->
+	    {Status, Reason} = esip:error_status(Err),
+	    esip:reply(TrID, mod_sip:make_response(
+			       Req, #sip{type = response,
+					 status = Status,
+					 reason = Reason})),
+	    {stop, normal, State}
+    end;
+wait_for_request(_Event, State) ->
+    {next_state, wait_for_request, State}.
+
+wait_for_response({#sip{method = <<"CANCEL">>, type = request}, _TrID}, State) ->
+    esip:cancel(State#state.client_trid),
+    {next_state, wait_for_response, State};
+wait_for_response({Resp, _TrID}, State) ->
+    case Resp of
+        {error, _} ->
+	    Req = State#state.orig_req,
+            {Status, Reason} = esip:error_status(Resp),
+            case Status of
+                408 when Req#sip.method /= <<"INVITE">> ->
+                    %% Absorb useless 408. See RFC4320
+                    esip:stop_transaction(State#state.orig_trid);
+                _ ->
+                    ErrResp = mod_sip:make_response(
+				Req,
+				#sip{type = response,
+				     status = Status,
+				     reason = Reason}),
+		    esip:reply(State#state.orig_trid, ErrResp)
+            end,
+            {stop, normal, State};
+        #sip{status = 100} ->
+            {next_state, wait_for_response, State};
+        #sip{status = Status} ->
+            case esip:split_hdrs('via', Resp#sip.hdrs) of
+                {[_], _} ->
+                    {stop, normal, State};
+                {[_|Vias], NewHdrs} ->
+                    esip:reply(State#state.orig_trid,
+                               Resp#sip{hdrs = [{'via', Vias}|NewHdrs]}),
+                    if Status < 200 ->
+                            {next_state, wait_for_response, State};
+                       true ->
+                            {stop, normal, State}
+                    end
+            end
+    end;
+wait_for_response(_Event, State) ->
+    {next_state, wait_for_response, State}.
+
+handle_event(_Event, StateName, State) ->
+    {next_state, StateName, State}.
+
+handle_sync_event(_Event, _From, StateName, State) ->
+    Reply = ok,
+    {reply, Reply, StateName, State}.
+
+handle_info(_Info, StateName, State) ->
+    {next_state, StateName, State}.
+
+terminate(_Reason, _StateName, _State) ->
+    ok.
+
+code_change(_OldVsn, StateName, State, _Extra) ->
+    {ok, StateName, State}.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+connect(Req, Opts) ->
+    case proplists:get_value(socket, Opts) of
+	undefined ->
+	    esip:connect(Req, Opts);
+	#sip_socket{} = SIPSock ->
+	    {ok, SIPSock}
+    end.