Add sockname to the info struct

README.md

@@ -135,6 +135,7 @@ simple. It has just a couple of methods:
      to this connection. You should see:
 
        * peername - ip address and port of the remote host
+       * sockname - ip address and port of the local endpoint
        * path - the path used by the request that started the connection
        * headers - a set of headers extracted from the request that
          may be handy (don't expect to retrieve Cookie header).

src/sockjs_handler.erl

@@ -211,7 +211,8 @@ default_logger(_Service, Req, _Type) ->
 
 -spec extract_info(req()) -> {info(), req()}.
 extract_info(Req) ->
-    {Peer, Req1}    = sockjs_http:peer(Req),
+    {Peer, Req0}    = sockjs_http:peername(Req),
+    {Sock, Req1}    = sockjs_http:sockname(Req0),
     {Path, Req2}    = sockjs_http:path(Req1),
     {Headers, Req3} = lists:foldl(fun (H, {Acc, R0}) ->
                                           case sockjs_http:header(H, R0) of
@@ -222,5 +223,6 @@ extract_info(Req) ->
                                   ['Referer', 'X-Client-Ip', 'X-Forwarded-For',
                                    'X-Cluster-Client-Ip', 'Via', 'X-Real-Ip']),
     {[{peername, Peer},
+      {sockname, Sock},
       {path, Path},
       {headers, Headers}], Req3}.

src/sockjs_http.erl

@@ -1,7 +1,7 @@
 -module(sockjs_http).
 
 -export([path/1, method/1, body/1, body_qs/1, header/2, jsessionid/1,
-         callback/1, peer/1]).
+         callback/1, peername/1, sockname/1]).
 -export([reply/4, chunk_start/3, chunk/2, chunk_end/1]).
 -export([hook_tcp_close/1, unhook_tcp_close/1, abruptly_kill/1]).
 -include("sockjs_internal.hrl").
@@ -70,11 +70,23 @@ callback({cowboy, Req}) ->
         _         -> {binary_to_list(CB), {cowboy, Req1}}
     end.
 
--spec peer(req()) -> {{inet:ip_address(), non_neg_integer()}, req()}.
-peer({cowboy, Req}) ->
+-spec peername(req()) -> {{inet:ip_address(), non_neg_integer()}, req()}.
+peername({cowboy, Req}) ->
     {P, Req1} = cowboy_http_req:peer(Req),
     {P, {cowboy, Req1}}.
 
+-spec sockname(req()) -> {{inet:ip_address(), non_neg_integer()}, req()}.
+sockname({cowboy, Req} = R) ->
+    {ok, _T, S} = cowboy_http_req:transport(Req),
+    %% Cowboy has peername(), but doesn't have sockname() equivalent.
+    {ok, Addr} = case S of
+                     _ when is_port(S) ->
+                         inet:sockname(S);
+                     _ ->
+                         {{0,0,0,0}, 0}
+                 end,
+    {Addr, R}.
+
 %% --------------------------------------------------------------------------
 
 -spec reply(non_neg_integer(), headers(), iodata(), req()) -> req().