Add support for proxy protocol

This add support for version 1 and 2 of protocol specified in
http://www.haproxy.org/download/1.8/doc/proxy-protocol.txt

To enable it you need add option use_proxy_protocol: true to listener.

rebar.config

@@ -24,7 +24,7 @@
         {fast_tls, ".*", {git, "https://github.com/processone/fast_tls", {tag, "1.0.26"}}},
         {stringprep, ".*", {git, "https://github.com/processone/stringprep", {tag, "1.0.14"}}},
         {fast_xml, ".*", {git, "https://github.com/processone/fast_xml", {tag, "1.1.34"}}},
-        {xmpp, ".*", {git, "https://github.com/processone/xmpp", {tag, "1.2.6"}}},
+        {xmpp, ".*", {git, "https://github.com/processone/xmpp", "2756f13fd2670b99a41c5a8d558b90528283ff6f"}},
         {fast_yaml, ".*", {git, "https://github.com/processone/fast_yaml", {tag, "1.0.17"}}},
         {jiffy, ".*", {git, "https://github.com/davisp/jiffy", {tag, "0.14.8"}}},
         {p1_oauth2, ".*", {git, "https://github.com/processone/p1_oauth2", {tag, "0.6.3"}}},

src/ejabberd_http.erl

@@ -69,7 +69,8 @@
 		default_host,
 		custom_headers,
 		trail = <<>>,
-		addr_re
+		addr_re,
+		sock_peer_name = none
 	       }).
 
 -define(XHTML_DOCTYPE,
@@ -143,6 +144,7 @@ init({SockMod, Socket}, Opts) ->
 		 true -> [{[], ejabberd_xmlrpc}];
 		 false -> []
 	     end,
+    SockPeer =  proplists:get_value(sock_peer_name, Opts, none),
     DefinedHandlers = proplists:get_value(request_handlers, Opts, []),
     RequestHandlers = DefinedHandlers ++ Captcha ++ Register ++
         Admin ++ Bind ++ XMLRPC,
@@ -159,6 +161,7 @@ init({SockMod, Socket}, Opts) ->
 		   custom_headers = CustomHeaders,
 		   options = Opts,
 		   request_handlers = RequestHandlers,
+		   sock_peer_name = SockPeer,
 		   addr_re = RE},
     try receive_headers(State) of
         V -> V
@@ -463,6 +466,7 @@ process_request(#state{request_method = Method,
 		       request_version = Version,
 		       sockmod = SockMod,
 		       socket = Socket,
+		       sock_peer_name = SockPeer,
 		       options = Options,
 		       request_host = Host,
 		       request_port = Port,
@@ -481,12 +485,16 @@ process_request(#state{request_method = Method,
 	{State2, false} ->
 	    {State2, make_bad_request(State)};
 	{State2, {LPath, LQuery, Data}} ->
-	    PeerName =
+	    PeerName = case SockPeer of
+			   none ->
 			       case SockMod of
 				   gen_tcp ->
 				       inet:peername(Socket);
 				   _ ->
 				       SockMod:peername(Socket)
+			       end;
+			   {_, Peer} ->
+			       {ok, Peer}
 		       end,
             IPHere = case PeerName of
                          {ok, V} -> V;

src/ejabberd_listener.erl

@@ -204,6 +204,28 @@ accept(ListenSocket, Module, Opts, Sup, Interval) ->
     NewInterval = check_rate_limit(Interval),
     case gen_tcp:accept(ListenSocket) of
 	{ok, Socket} ->
+	    case proplists:get_value(use_proxy_protocol, Opts, false) of
+		true ->
+		    case proxy_protocol:decode(gen_tcp, Socket, 10000) of
+			{error, Err} ->
+			    ?ERROR_MSG("(~w) Proxy protocol parsing failed: ~s",
+				       [ListenSocket, inet:format_error(Err)]),
+			    gen_tcp:close(Socket);
+			{{Addr, Port}, {PAddr, PPort}} = SP ->
+			    Opts2 = [{sock_peer_name, SP} | Opts],
+			    Receiver = case start_connection(Module, Socket, Opts2, Sup) of
+					   {ok, RecvPid} ->
+					       RecvPid;
+					   _ ->
+					       gen_tcp:close(Socket),
+					       none
+				       end,
+			    ?INFO_MSG("(~p) Accepted proxied connection ~s:~p -> ~s:~p",
+				      [Receiver,
+				       ejabberd_config:may_hide_data(inet_parse:ntoa(PAddr)),
+				       PPort, inet_parse:ntoa(Addr), Port])
+		    end;
+		_ ->
 		    case {inet:sockname(Socket), inet:peername(Socket)} of
 			{{ok, {Addr, Port}}, {ok, {PAddr, PPort}}} ->
 			    Receiver = case start_connection(Module, Socket, Opts, Sup) of
@@ -219,6 +241,7 @@ accept(ListenSocket, Module, Opts, Sup, Interval) ->
 				       PPort, inet_parse:ntoa(Addr), Port]);
 			_ ->
 			    gen_tcp:close(Socket)
+		    end
 	    end,
 	    accept(ListenSocket, Module, Opts, Sup, NewInterval);
 	{error, Reason} ->
@@ -665,7 +688,9 @@ listen_opt_type(max_fsm_queue) ->
 listen_opt_type(shaper) ->
     fun acl:shaper_rules_validator/1;
 listen_opt_type(access) ->
-    fun acl:access_rules_validator/1.
+    fun acl:access_rules_validator/1;
+listen_opt_type(use_proxy_protocol) ->
+    fun(B) when is_boolean(B) -> B end.
 
 listen_options() ->
     [module, port,
@@ -675,6 +700,7 @@ listen_options() ->
      {inet6, false},
      {accept_interval, 0},
      {backlog, 5},
+     {use_proxy_protocol, false},
      {supervisor, true}].
 
 opt_type(listen) -> fun validate_cfg/1;

src/proxy_protocol.erl

@@ -0,0 +1,182 @@
+%%%----------------------------------------------------------------------
+%%% File    : ejabberd_http.erl
+%%% Author  : Paweł Chmielowski <pawel@process-one.net>
+%%% Purpose :
+%%% Created : 27 Nov 2018 by Paweł Chmielowski <pawel@process-one.net>
+%%%
+%%%
+%%% ejabberd, Copyright (C) 2002-2018   ProcessOne
+%%%
+%%% This program is free software; you can redistribute it and/or
+%%% modify it under the terms of the GNU General Public License as
+%%% published by the Free Software Foundation; either version 2 of the
+%%% License, or (at your option) any later version.
+%%%
+%%% This program is distributed in the hope that it will be useful,
+%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
+%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+%%% General Public License for more details.
+%%%
+%%% You should have received a copy of the GNU General Public License along
+%%% with this program; if not, write to the Free Software Foundation, Inc.,
+%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+%%%
+%%%----------------------------------------------------------------------
+-module(proxy_protocol).
+-author("pawel@process-one.net").
+
+%% API
+-export([decode/3]).
+
+decode(SockMod, Socket, Timeout) ->
+    V = SockMod:recv(Socket, 6, Timeout),
+    case V of
+	{ok, <<"PROXY ">>} ->
+	    decode_v1(SockMod, Socket, Timeout);
+	{ok, <<16#0d, 16#0a, 16#0d, 16#0a, 16#00, 16#0d>>} ->
+	    decode_v2(SockMod, Socket, Timeout);
+	_ ->
+	    {error, eproto}
+    end.
+
+decode_v1(SockMod, Socket, Timeout) ->
+    case read_until_rn(SockMod, Socket, <<>>, false, Timeout) of
+	{error, _} = Err ->
+	    Err;
+	Val ->
+	    case binary:split(Val, <<" ">>, [global]) of
+		[<<"TCP4">>, SAddr, DAddr, SPort, DPort] ->
+		    try {inet_parse:ipv4strict_address(binary_to_list(SAddr)),
+			 inet_parse:ipv4strict_address(binary_to_list(DAddr)),
+			 binary_to_integer(SPort),
+			 binary_to_integer(DPort)}
+		    of
+			{{ok, DA}, {ok, SA}, DP, SP} ->
+			    {{SA, SP}, {DA, DP}};
+			_ ->
+			    {error, eproto}
+		    catch
+			error:badarg ->
+			    {error, eproto}
+		    end;
+		[<<"TCP6">>, SAddr, DAddr, SPort, DPort] ->
+		    try {inet_parse:ipv6strict_address(binary_to_list(SAddr)),
+			 inet_parse:ipv6strict_address(binary_to_list(DAddr)),
+			 binary_to_integer(SPort),
+			 binary_to_integer(DPort)}
+		    of
+			{{ok, DA}, {ok, SA}, DP, SP} ->
+			    {{SA, SP}, {DA, DP}};
+			_ ->
+			    {error, eproto}
+		    catch
+			error:badarg ->
+			    {error, eproto}
+		    end;
+		[<<"UNKNOWN">> | _] ->
+		    {undefined, undefined}
+	    end
+    end.
+
+decode_v2(SockMod, Socket, Timeout) ->
+    case SockMod:recv(Socket, 10, Timeout) of
+	{error, _} = Err ->
+	    Err;
+	{ok, <<16#0a, 16#51, 16#55, 16#49, 16#54, 16#0a,
+	       2:4, Command:4, Transport:8, AddrLen:16/big-unsigned-integer>>} ->
+	    case SockMod:recv(Socket, AddrLen, Timeout) of
+		{error, _} = Err ->
+		    Err;
+		{ok, Data} ->
+		    case Command of
+			0 ->
+			    case {inet:sockname(Socket), inet:peername(Socket)} of
+				{{ok, SA}, {ok, DA}} ->
+				    {SA, DA};
+				{{error, _} = E, _} ->
+				    E;
+				{_, {error, _} = E} ->
+				    E
+			    end;
+			1 ->
+			    case Transport of
+				% UNSPEC or UNIX
+				V when V == 0; V == 16#31; V == 16#32 ->
+				    {{unknown, unknown}, {unknown, unknown}};
+				% IPV4 over TCP or UDP
+				V when V == 16#11; V == 16#12 ->
+				    case Data of
+					<<D1:8, D2:8, D3:8, D4:8,
+					  S1:8, S2:8, S3:8, S4:8,
+					  DP:16/big-unsigned-integer,
+					  SP:16/big-unsigned-integer>> ->
+					    {{{S1, S2, S3, S4}, SP},
+					     {{D1, D2, D3, D4}, DP}};
+					_ ->
+					    {error, eproto}
+				    end;
+				% IPV6 over TCP or UDP
+				V when V == 16#21; V == 16#22 ->
+				    case Data of
+					<<D1:16/big-unsigned-integer,
+					  D2:16/big-unsigned-integer,
+					  D3:16/big-unsigned-integer,
+					  D4:16/big-unsigned-integer,
+					  D5:16/big-unsigned-integer,
+					  D6:16/big-unsigned-integer,
+					  D7:16/big-unsigned-integer,
+					  D8:16/big-unsigned-integer,
+					  S1:16/big-unsigned-integer,
+					  S2:16/big-unsigned-integer,
+					  S3:16/big-unsigned-integer,
+					  S4:16/big-unsigned-integer,
+					  S5:16/big-unsigned-integer,
+					  S6:16/big-unsigned-integer,
+					  S7:16/big-unsigned-integer,
+					  S8:16/big-unsigned-integer,
+					  DP:16/big-unsigned-integer,
+					  SP:16/big-unsigned-integer>> ->
+					    {{{S1, S2, S3, S4, S5, S6, S7, S8}, SP},
+					     {{D1, D2, D3, D4, D5, D6, D7, D8}, DP}};
+					_ ->
+					    {error, eproto}
+				    end
+			    end;
+			_ ->
+			    {error, eproto}
+		    end
+	    end;
+	<<16#0a, 16#51, 16#55, 16#49, 16#54, 16#0a, _/binary>> ->
+	    {error, eproto};
+	_ ->
+	    {error, eproto}
+    end.
+
+read_until_rn(_SockMod, _Socket, Data, _, _) when size(Data) > 107 ->
+    {error, eproto};
+read_until_rn(SockMod, Socket, Data, true, Timeout) ->
+    case SockMod:recv(Socket, 1, Timeout) of
+	{ok, <<"\n">>} ->
+	    Data;
+	{ok, <<"\r">>} ->
+	    read_until_rn(SockMod, Socket, <<Data/binary, "\r">>,
+			  true, Timeout);
+	{ok, Other} ->
+	    read_until_rn(SockMod, Socket, <<Data/binary, "\r", Other/binary>>,
+			  false, Timeout);
+	{error, _} = Err ->
+	    Err
+    end;
+read_until_rn(SockMod, Socket, Data, false, Timeout) ->
+    case SockMod:recv(Socket, 2, Timeout) of
+	{ok, <<"\r\n">>} ->
+	    Data;
+	{ok, <<Byte:8, "\r">>} ->
+	    read_until_rn(SockMod, Socket, <<Data/binary, Byte:8>>,
+			  true, Timeout);
+	{ok, Other} ->
+	    read_until_rn(SockMod, Socket, <<Data/binary, Other/binary>>,
+			  false, Timeout);
+	{error, _} = Err ->
+	    Err
+    end.