From 4915195b1e1f1e5a06a0cdd7b450251aaa9d2f90 Mon Sep 17 00:00:00 2001
From: Feng Lee <feng@emqtt.io>
Date: Sat, 2 Dec 2017 17:59:16 +0800
Subject: [PATCH] Fix issue #1335 - Forward real client IP using a reverse
 proxy for websocket

---
 src/emqttd_ws_client.erl     | 33 ++-------------------------------
 src/emqttd_ws_client_sup.erl | 19 +------------------
 2 files changed, 3 insertions(+), 49 deletions(-)

diff --git a/src/emqttd_ws_client.erl b/src/emqttd_ws_client.erl
index 7a66dff3c..b9d25ad3e 100644
--- a/src/emqttd_ws_client.erl
+++ b/src/emqttd_ws_client.erl
@@ -28,7 +28,7 @@
 
 -include("emqttd_internal.hrl").
 
--import(proplists, [get_value/3, get_value/2]).
+-import(proplists, [get_value/3]).
 
 %% API Exports
 -export([start_link/4]).
@@ -93,7 +93,7 @@ init([Env, WsPid, Req, ReplyChannel]) ->
     process_flag(trap_exit, true),
     Conn = Req:get(connection),
     true = link(WsPid),
-    case peername(Env, Req) of
+    case Req:get(peername) of
         {ok, Peername} ->
             Headers = mochiweb_headers:to_list(
                         mochiweb_request:get(headers, Req)),
@@ -321,32 +321,3 @@ gc(State) ->
     Cb = fun() -> emit_stats(State) end,
     emqttd_gc:maybe_force_gc(#wsclient_state.force_gc_count, State, Cb).
 
-peername(Env, Req) ->
-    Conn = Req:get(connection),
-    case Conn:peername() of
-        {ok, Peername} ->
-            % return original address, if existed
-            case last_forwarded(get_value(Conn:type(), Env, []), Req) of
-                undefined -> {ok, Peername};
-                Forwarded -> {ok, Forwarded}
-            end;
-        {error, Reason} -> {error, Reason}
-    end.
-
-last_forwarded([], _) -> undefined;
-last_forwarded(Conf, Req) ->
-    HostHeader = get_value(proxy_ipaddress_header, Conf),
-    PortHeader = get_value(proxy_port_header, Conf),
-    case tune_host(Req:get_header_value(HostHeader)) of
-        undefined -> undefined;
-        Host -> {Host, tune_port(Req:get_header_value(PortHeader))}
-    end.
-
-tune_host(undefined) -> undefined;
-tune_host(Hosts) ->
-    {ok, Last} = inet:parse_address(string:strip(lists:last(string:tokens(Hosts, ",")))),
-    Last.
-
-tune_port(undefined) -> undefined;
-tune_port(Port) -> list_to_integer(Port).
-
diff --git a/src/emqttd_ws_client_sup.erl b/src/emqttd_ws_client_sup.erl
index ec46b8714..21f683eaa 100644
--- a/src/emqttd_ws_client_sup.erl
+++ b/src/emqttd_ws_client_sup.erl
@@ -39,25 +39,8 @@ start_client(WsPid, Req, ReplyChannel) ->
 %%--------------------------------------------------------------------
 
 init([]) ->
-    Env = lists:append(emqttd:env(client, []),
-                       emqttd:env(protocol, []) ++ forwarded_header()),
+    Env = lists:append(emqttd:env(client, []), emqttd:env(protocol, [])),
     {ok, {{simple_one_for_one, 0, 1},
            [{ws_client, {emqttd_ws_client, start_link, [Env]},
              temporary, 5000, worker, [emqttd_ws_client]}]}}.
 
-forwarded_header() ->
-    Env = [{Proto, Opts} || {Proto, _, Opts} <- emqttd:env(listeners, []), Proto == ws orelse Proto == wss],
-    lists:foldl(fun({Proto, Opts}, Acc) ->
-                  Proto1 = case Proto of
-                               ws  -> tcp;
-                               wss -> ssl
-                           end,
-                  case {proplists:get_value(proxy_ipaddress_header, Opts),
-                          proplists:get_value(proxy_port_header, Opts)} of
-                      {undefined, _}           -> Acc;
-                      {AddrHeader, undefined}  -> [{Proto1, [{proxy_ipaddress_header, AddrHeader}]} | Acc];
-                      {AddrHeader, PortHeader} -> [{Proto1, [{proxy_ipaddress_header, AddrHeader},
-                                                             {proxy_port_header, PortHeader}]} | Acc]
-                  end
-              end, [], Env).
-