correctly handle half-open connections

1 files changed, 15 insertions, 10 deletions

diff --git a/ereproxy_server.erl b/ereproxy_server.erl
index ef59144..a6e9803 100644
--- a/ereproxy_server.erl
+++ b/ereproxy_server.erl
@@ -1,6 +1,6 @@
 -module(ereproxy_server).
 -behavior(supervisor).
--export([start_link/1, init/1, start_link_acceptor/2, acceptor/2, con/2, pass_through/1]).
+-export([start_link/1, init/1, start_link_acceptor/2, acceptor/2, con/2, pass_through/2]).
 
 -include("ereproxy_config.hrl").
 
@@ -36,7 +36,8 @@ tp_t2c(ssl) -> ssl_closed.
 %%% listen and accept on a single port
 
 start_link_acceptor(CfgMod, {Method, ListenPort}) ->     
-    DefaultOpts = [binary, {packet, 0}, {active, false}, {reuseaddr, true}],
+    DefaultOpts = [binary, {packet, 0}, {active, false},
+		   {exit_on_close, false}, {reuseaddr, true}],
     {TP, Opts} =
 	case Method of
 	    http -> {tcp, DefaultOpts};
@@ -67,7 +68,8 @@ con(CfgMod, ClientCon = {TP, ClientSock}) ->
     {ConHead, HostName} = parse_header(MaxCache, ClientCon),
     {Host, Port} = CfgMod:select_destination(HostName),
     % connect to destination
-    {ok, ServerSock} = gen_tcp:connect(Host, Port, [binary, {packet, 0}, {active, once}]),
+    TCPOpts = [binary, {packet, 0}, {active, once}, {exit_on_close, false}],
+    {ok, ServerSock} = gen_tcp:connect(Host, Port, TCPOpts),
     % log redirection details
     {ok, {SrcAddr, SrcPort}} = tp(TP, peername, [ClientSock]),
     {ok, {RedAddr, RedPort}} = inet:sockname(ServerSock),
@@ -75,7 +77,7 @@ con(CfgMod, ClientCon = {TP, ClientSock}) ->
     ereproxy_log ! {{SrcAddr, SrcPort}, {RedAddr, RedPort}, {DstAddr, DstPort}},
     % pass through connection
     gen_tcp:send(ServerSock, ConHead),
-    pass_through([ClientCon, {tcp, ServerSock}]).
+    pass_through([ClientCon, {tcp, ServerSock}], 2).
 
 %% parse_header: search for the "^Host: " field
 
@@ -114,18 +116,21 @@ parse_header(MaxCache, Con) ->
     parse_header(MaxCache, Con, <<>>, <<>>, <<>>).
 
 %% connect client and destination server
-pass_through(Cons) ->
+pass_through(_Cons, 0) ->
+	    connections_closed;
+pass_through(Cons, NumOpen) ->
     receive
 	{STP, Src, Data} ->
 	    [{DTP, Dst}] = lists:subtract(Cons, [{STP, Src}]),
 	    ok = tp(STP, setopts, [Src, [{active, once}]]),
 	    ok = tp(DTP, send, [Dst, Data]),
-	    ?MODULE:pass_through(Cons); % allow code update
+	    ?MODULE:pass_through(Cons, NumOpen); % allow code update
 	{STP_Closed, Src} ->
 	    STP = tp_c2t(STP_Closed),
 	    [{DTP, Dst}] = lists:subtract(Cons, [{STP, Src}]),
-	    ok = tp(DTP, close, [Dst]),
-	    connections_closed
-   	    % TODO: check if this is standart compliant; we close both
-   	    % sides if one side closes one channel!
+	    ok = case NumOpen of
+		     2 -> tp(DTP, shutdown, [Dst, write]);
+		     1 -> ok
+		 end,
+	    ?MODULE:pass_through(Cons, NumOpen-1)
     end.