binary refactoring

1 files changed, 384 insertions, 338 deletions

diff --git a/src/web/ejabberd_websocket.erl b/src/web/ejabberd_websocket.erl
index 8030842a0..fde8baff6 100644
--- a/src/web/ejabberd_websocket.erl
+++ b/src/web/ejabberd_websocket.erl
@@ -8,12 +8,12 @@
 %%% (http://github.com/ostinelli/misultin/blob/master/src/misultin_websocket.erl)
 %%% Copyright (C) 2010, Roberto Ostinelli <roberto@ostinelli.net>, Joe Armstrong.
 %%% All rights reserved.
-%%% 
+%%%
 %%% Code portions from Joe Armstrong have been originally taken under MIT license at the address:
 %%% <http://armstrongonsoftware.blogspot.com/2009/12/comet-is-dead-long-live-websockets.html>
 %%%
 %%% BSD License
-%%% 
+%%%
 %%% Redistribution and use in source and binary forms, with or without modification, are permitted provided
 %%% that the following conditions are met:
 %%%
@@ -36,400 +36,446 @@
 %%% ejabberd, Copyright (C) 2002-2010   ProcessOne
 %%%----------------------------------------------------------------------
 
--module (ejabberd_websocket).
+-module(ejabberd_websocket).
+
 -author('ecestari@process-one.net').
+
 -export([connect/2, check/2, is_acceptable/1]).
+
 -include("ejabberd.hrl").
+
 -include("jlib.hrl").
+
 -include("ejabberd_http.hrl").
 
-check(_Path, Headers)->
-	% set supported websocket protocols, order does matter
-	VsnSupported = [{'draft-hybi', 8}, {'draft-hybi', 13}, {'draft-hixie', 0}, {'draft-hixie', 68}],
-	% checks
-	check_websockets(VsnSupported, Headers).
+check(_Path, Headers) ->
+    VsnSupported = [{'draft-hybi', 8}, {'draft-hybi', 13},
+		    {'draft-hixie', 0}, {'draft-hixie', 68}],
+    check_websockets(VsnSupported, Headers).
 
-% Checks if websocket can be access by client
-% If origins are set in configuration, check if it belongs
-% If origins not set, access is open.
-is_acceptable(#ws{origin=Origin, protocol=Protocol, 
-                  headers = Headers, acceptable_origins = Origins, auth_module=undefined})->
-  ClientProtocol = lists:keyfind("Sec-Websocket-Protocol",1, Headers),
-  case {(Origins == []) or lists:member(Origin, Origins), ClientProtocol, Protocol } of
-    {false, _, _} -> 
-      ?INFO_MSG("client does not come from authorized origin", []),
-      false;
-    {_, false, _} -> 
-      true;
-    {_, {_, P}, P} -> 
-      true;
-    _ = E-> 
-     ?INFO_MSG("Wrong protocol requested : ~p", [E]),
-    false
-  end;
-is_acceptable(#ws{local_path=LocalPath, origin=Origin, ip=IP, q=Q, protocol=Protocol, headers = Headers,auth_module=Module})->
-  Module:is_acceptable(LocalPath, Q, Origin, Protocol, IP, Headers).   
+is_acceptable(#ws{origin = Origin, protocol = Protocol,
+		  headers = Headers, acceptable_origins = Origins,
+		  auth_module = undefined}) ->
+    ClientProtocol =
+	lists:keyfind(<<"Sec-Websocket-Protocol">>, 1, Headers),
+    case {(Origins == []) or lists:member(Origin, Origins),
+	  ClientProtocol, Protocol}
+	of
+      {false, _, _} ->
+	  ?INFO_MSG("client does not come from authorized "
+		    "origin",
+		    []),
+	  false;
+      {_, false, _} -> true;
+      {_, {_, P}, P} -> true;
+      _ = E ->
+	  ?INFO_MSG("Wrong protocol requested : ~p", [E]), false
+    end;
+is_acceptable(#ws{local_path = LocalPath,
+		  origin = Origin, ip = IP, q = Q, protocol = Protocol,
+		  headers = Headers, auth_module = Module}) ->
+    Module:is_acceptable(LocalPath, Q, Origin, Protocol, IP,
+			 Headers).
 
-% Connect and handshake with Websocket.
-connect(#ws{vsn = Vsn, socket = Socket, q=Q,origin=Origin, host=Host, port=Port, sockmod = SockMod, path = Path, headers = Headers, ws_autoexit = WsAutoExit} = Ws, WsLoop) ->
-  	% build handshake
-  	HandshakeServer = handshake(Vsn, Socket,SockMod, Headers, {Path, Q, Origin, Host, Port}),
-  	% send handshake back
-  	SockMod:send(Socket, HandshakeServer),
-  	?DEBUG("Sent handshake response : ~p", [HandshakeServer]),
-  	Ws0 = ejabberd_ws:new(Ws#ws{origin = Origin, host = Host}, self()),
-  	%?DEBUG("Ws0 : ~p",[Ws0]),
-  	% add data to ws record and spawn controlling process
-  	{ok, WsHandleLoopPid} = WsLoop:start_link(Ws0),
-  	erlang:monitor(process, WsHandleLoopPid),
-  	% set opts
-  	case SockMod of
-  	  gen_tcp ->
-  	    inet:setopts(Socket, [{packet, 0}, {active, true}]);
-  	  _ ->
-  	    SockMod:setopts(Socket, [{packet, 0}, {active, true}])
-  	end,
-  	% start listening for incoming data
-        ws_loop(Vsn, none, Socket, WsHandleLoopPid, SockMod, WsAutoExit).
+connect(#ws{vsn = Vsn, socket = Socket, q = Q,
+	    origin = Origin, host = Host, port = Port,
+	    sockmod = SockMod, path = Path, headers = Headers,
+	    ws_autoexit = WsAutoExit} =
+	    Ws,
+	WsLoop) ->
+    HandshakeServer = handshake(Vsn, Socket, SockMod,
+				Headers, {Path, Q, Origin, Host, Port}),
+    SockMod:send(Socket, HandshakeServer),
+    ?DEBUG("Sent handshake response : ~p",
+	   [HandshakeServer]),
+    Ws0 = ejabberd_ws:new(Ws#ws{origin = Origin,
+				host = Host},
+			  self()),
+    {ok, WsHandleLoopPid} = WsLoop:start_link(Ws0),
+    erlang:monitor(process, WsHandleLoopPid),
+    case SockMod of
+      gen_tcp ->
+	  inet:setopts(Socket, [{packet, 0}, {active, true}]);
+      _ ->
+	  SockMod:setopts(Socket, [{packet, 0}, {active, true}])
+    end,
+    ws_loop(Vsn, none, Socket, WsHandleLoopPid, SockMod,
+	    WsAutoExit).
 
-	
 check_websockets([], _Headers) -> false;
-check_websockets([Vsn|T], Headers) ->
-	case check_websocket(Vsn, Headers) of
-		false -> check_websockets(T, Headers);
-		Value -> Value
-	end.
+check_websockets([Vsn | T], Headers) ->
+    case check_websocket(Vsn, Headers) of
+      false -> check_websockets(T, Headers);
+      Value -> Value
+    end.
 
-% Function: {true, Vsn} | false
-% Description: Check if the incoming request is a websocket request.
 check_websocket({'draft-hixie', 0} = Vsn, Headers) ->
-	%?DEBUG("testing for websocket protocol ~p", [Vsn]),
-	% set required headers
-	RequiredHeaders = [
-		{'Upgrade', "WebSocket"}, {'Connection', "Upgrade"}, {'Host', ignore}, {"Origin", ignore},
-		{"Sec-Websocket-Key1", ignore}, {"Sec-Websocket-Key2", ignore}
-	],
-	% check for headers existance
-	case check_headers(Headers, RequiredHeaders) of
-		true ->
-			% return
-            {true, Vsn};
-		_RemainingHeaders ->
-			%?DEBUG("not protocol ~p, remaining headers: ~p", [Vsn, _RemainingHeaders]),
-			false
-	end;
+    RequiredHeaders = [{'Upgrade', <<"WebSocket">>},
+		       {'Connection', <<"Upgrade">>}, {'Host', ignore},
+		       {<<"Origin">>, ignore},
+		       {<<"Sec-Websocket-Key1">>, ignore},
+		       {<<"Sec-Websocket-Key2">>, ignore}],
+    case check_headers(Headers, RequiredHeaders) of
+      true -> {true, Vsn};
+      _RemainingHeaders ->
+	  %?DEBUG("not protocol ~p, remaining headers: ~p", [Vsn, _RemainingHeaders]),
+	  false
+    end;
 check_websocket({'draft-hixie', 68} = Vsn, Headers) ->
-	%?DEBUG("testing for websocket protocol ~p", [Vsn]),
-	% set required headers
-	RequiredHeaders = [
-		{'Upgrade', "WebSocket"}, {'Connection', "Upgrade"}, {'Host', ignore}, {"Origin", ignore}
-	],
-	% check for headers existance
-	case check_headers(Headers, RequiredHeaders) of
-		true -> {true, Vsn};
-		_RemainingHeaders ->
-			%?DEBUG("not protocol ~p, remaining headers: ~p", [Vsn, _RemainingHeaders]),
-			false
-	end;
+    RequiredHeaders = [{'Upgrade', <<"WebSocket">>},
+		       {'Connection', <<"Upgrade">>}, {'Host', ignore},
+		       {<<"Origin">>, ignore}],
+    case check_headers(Headers, RequiredHeaders) of
+      true -> {true, Vsn};
+      _RemainingHeaders ->
+	  %?DEBUG("not protocol ~p, remaining headers: ~p", [Vsn, _RemainingHeaders]),
+	  false
+    end;
 check_websocket({'draft-hybi', 8} = Vsn, Headers) ->
-	%?DEBUG("testing for websocket protocol ~p", [Vsn]),
-	% set required headers
-	RequiredHeaders = [
-                           {'Upgrade', "websocket"}, {'Connection', ignore}, {'Host', ignore},
-                           {"Sec-Websocket-Key", ignore}, {"Sec-Websocket-Version", "8"}
-                          ],
-	% check for headers existance
-	case check_headers(Headers, RequiredHeaders) of
-		true -> {true, Vsn};
-		RemainingHeaders ->
-			%%?INFO_MSG("not protocol ~p, remaining headers: ~p", [Vsn, RemainingHeaders]),
-			false
-	end;
+    RequiredHeaders = [{'Upgrade', <<"websocket">>},
+		       {'Connection', ignore}, {'Host', ignore},
+		       {<<"Sec-Websocket-Key">>, ignore},
+		       {<<"Sec-Websocket-Version">>, <<"8">>}],
+    case check_headers(Headers, RequiredHeaders) of
+      true -> {true, Vsn};
+      _RemainingHeaders ->
+	  %%?INFO_MSG("not protocol ~p, remaining headers: ~p", [Vsn, RemainingHeaders]),
+	  false
+    end;
 check_websocket({'draft-hybi', 13} = Vsn, Headers) ->
-	%?DEBUG("testing for websocket protocol ~p", [Vsn]),
-	% set required headers
-	RequiredHeaders = [
-                           {'Upgrade', "websocket"}, {'Connection', ignore}, {'Host', ignore},
-                           {"Sec-Websocket-Key", ignore}, {"Sec-Websocket-Version", "13"}
-                          ],
-	% check for headers existance
-	case check_headers(Headers, RequiredHeaders) of
-		true -> {true, Vsn};
-		RemainingHeaders ->
-			%%?INFO_MSG("not protocol ~p, remaining headers: ~p", [Vsn, RemainingHeaders]),
-			false
-	end;
-check_websocket(_Vsn, _Headers) -> false. % not implemented
+    RequiredHeaders = [{'Upgrade', <<"websocket">>},
+		       {'Connection', ignore}, {'Host', ignore},
+		       {<<"Sec-Websocket-Key">>, ignore},
+		       {<<"Sec-Websocket-Version">>, <<"13">>}],
+    case check_headers(Headers, RequiredHeaders) of
+      true -> {true, Vsn};
+      _RemainingHeaders ->
+	  %%?INFO_MSG("not protocol ~p, remaining headers: ~p", [Vsn, RemainingHeaders]),
+	  false
+    end.
 
-% Function: true | [{RequiredTag, RequiredVal}, ..]
-% Description: Check if headers correspond to headers requirements.
 check_headers(Headers, RequiredHeaders) ->
-	F = fun({Tag, Val}) ->
-		% see if the required Tag is in the Headers
-        case lists:keyfind(Tag, 1, Headers) of
-			false -> true; % header not found, keep in list
-			{_, HVal} ->
-			  %?DEBUG("check: ~p", [{Tag, HVal,Val }]),
-				case Val of
-					ignore -> false; % ignore value -> ok, remove from list
-					HVal -> false;	 % expected val -> ok, remove from list
-					_ -> true		 % val is different, keep in list
-				end		
+    F = fun ({Tag, Val}) ->
+		case lists:keyfind(Tag, 1, Headers) of
+		  false -> true; % header not found, keep in list
+		  {_, HVal} ->
+		      case Val of
+			ignore -> false; % ignore value -> ok, remove from list
+			HVal -> false;   % expected val -> ok, remove from list
+			_ ->
+			    true                % val is different, keep in list
+		      end
 		end
 	end,
-	case lists:filter(F, RequiredHeaders) of
-		[] -> true;
-		MissingHeaders -> MissingHeaders
-	end.
+    case lists:filter(F, RequiredHeaders) of
+      [] -> true;
+      MissingHeaders -> MissingHeaders
+    end.
 
-% Function: List
-% Description: Builds the server handshake response.
-handshake({'draft-hixie', 0}, Sock,SocketMod, Headers, {Path, Q,Origin, Host, Port}) ->
-	% build data
-	{_, Key1} = lists:keyfind("Sec-Websocket-Key1",1, Headers),
-	{_, Key2} = lists:keyfind("Sec-Websocket-Key2",1, Headers),
-	HostPort = case lists:keyfind('Host', 1, Headers) of
-		{_, Value} -> Value;
-		_ -> string:join([Host, integer_to_list(Port)],":")
-	end,
-	% handshake needs body of the request, still need to read it [TODO: default recv timeout hard set, will be exported when WS protocol is final]
-	case SocketMod of
-	  gen_tcp ->
-	    inet:setopts(Sock, [{packet, raw}, {active, false}]);
-	  _ ->
-	    SocketMod:setopts(Sock, [{packet, raw}, {active, false}])
-	end,
-	Body = case SocketMod:recv(Sock, 8, 30*1000) of
-		{ok, Bin} -> Bin;
-		{error, timeout} ->
-			?WARNING_MSG("timeout in reading websocket body", []),
-			<<>>; 
-		_Other ->
-			?ERROR_MSG("tcp error treating data: ~p", [_Other]),
-			<<>>
-	end,
-	QParams = lists:map(
-	        fun({nokey,[]})->
-	            none;
-	           ({K, V})->
-	              K ++ "=" ++ V
-	    end, Q),
-	QString = case QParams of
-	    [none]-> "";
-	    QParams-> "?" ++ string:join(QParams, "&")
-	end,       
-	%?DEBUG("got content in body of websocket request: ~p, ~p", [Body,string:join([Host, Path],"/")]),	
-	% prepare handhsake response
-	["HTTP/1.1 101 WebSocket Protocol Handshake\r\n",
-		"Upgrade: WebSocket\r\n",
-		"Connection: Upgrade\r\n",
-		"Sec-WebSocket-Origin: ", Origin, "\r\n",
-		"Sec-WebSocket-Location: ws://", HostPort, "/", string:join(Path,"/"),
-		QString, "\r\n\r\n",
-		build_challenge({'draft-hixie', 0}, {Key1, Key2, Body})
-	];
-handshake({'draft-hixie', 68}, _Sock,_SocketMod, Headers, {Path, Origin, Host, Port}) ->
-	HostPort = case lists:keyfind('Host', 1, Headers) of
-		{_, Value} -> Value;
-		_ -> string:join([Host, integer_to_list(Port)],":")
-	end,
-	["HTTP/1.1 101 Web Socket Protocol Handshake\r\n",
-		"Upgrade: WebSocket\r\n",
-		"Connection: Upgrade\r\n",
-		"WebSocket-Origin: ", Origin , "\r\n",
-		"WebSocket-Location: ws://", HostPort, "/", string:join(Path,"/"),"\r\n\r\n"
-	];
-handshake({'draft-hybi', _}, Sock,SocketMod, Headers, {Path, Q,Origin, Host, Port}) ->
-	{_, Key} = lists:keyfind("Sec-Websocket-Key",1, Headers),
-	Hash = jlib:encode_base64(binary_to_list(sha:sha1(Key++"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"))),
-	["HTTP/1.1 101 Switching Protocols\r\n",
-		"Upgrade: websocket\r\n",
-		"Connection: Upgrade\r\n",
-		"Sec-WebSocket-Accept: ", Hash, "\r\n\r\n"
-	].
+handshake({'draft-hixie', 0}, Sock, SocketMod, Headers,
+	  {Path, Q, Origin, Host, Port}) ->
+    {_, Key1} = lists:keyfind(<<"Sec-Websocket-Key1">>, 1,
+			      Headers),
+    {_, Key2} = lists:keyfind(<<"Sec-Websocket-Key2">>, 1,
+			      Headers),
+    HostPort = case lists:keyfind('Host', 1, Headers) of
+		 {_, Value} -> Value;
+		 _ ->
+		     str:join([Host,
+			       jlib:integer_to_binary(Port)],
+			      <<":">>)
+	       end,
+    case SocketMod of
+      gen_tcp ->
+	  inet:setopts(Sock, [{packet, raw}, {active, false}]);
+      _ ->
+	  SocketMod:setopts(Sock,
+			    [{packet, raw}, {active, false}])
+    end,
+    Body = case SocketMod:recv(Sock, 8, 30 * 1000) of
+	     {ok, Bin} -> Bin;
+	     {error, timeout} ->
+		 ?WARNING_MSG("timeout in reading websocket body", []),
+		 <<>>;
+	     _Other ->
+		 ?ERROR_MSG("tcp error treating data: ~p", [_Other]),
+		 <<>>
+	   end,
+    QParams = lists:map(fun ({nokey, <<>>}) -> none;
+			    ({K, V}) -> <<K/binary, "=", V/binary>>
+			end,
+			Q),
+    QString = case QParams of
+		[none] -> <<"">>;
+		QParams -> <<"?", (str:join(QParams, <<"&">>))/binary>>
+	      end,
+    [<<"HTTP/1.1 101 WebSocket Protocol Handshake\r\n">>,
+     <<"Upgrade: WebSocket\r\n">>,
+     <<"Connection: Upgrade\r\n">>,
+     <<"Sec-WebSocket-Origin: ">>, Origin, <<"\r\n">>,
+     <<"Sec-WebSocket-Location: ws://">>, HostPort, <<"/">>,
+     str:join(Path, <<"/">>), QString, <<"\r\n\r\n">>,
+     build_challenge({'draft-hixie', 0},
+		     {Key1, Key2, Body})];
+handshake({'draft-hixie', 68}, _Sock, _SocketMod,
+	  Headers, {Path, _Q, Origin, Host, Port}) ->
+    HostPort = case lists:keyfind('Host', 1, Headers) of
+		 {_, Value} -> Value;
+		 _ ->
+		     str:join([Host,
+			       iolist_to_binary(integer_to_list(Port))],
+			      <<":">>)
+	       end,
+    [<<"HTTP/1.1 101 Web Socket Protocol Handshake\r\n">>,
+     <<"Upgrade: WebSocket\r\n">>,
+     <<"Connection: Upgrade\r\n">>, <<"WebSocket-Origin: ">>,
+     Origin, <<"\r\n">>, <<"WebSocket-Location: ws://">>,
+     HostPort, <<"/">>, str:join(Path, <<"/">>),
+     <<"\r\n\r\n">>];
+handshake({'draft-hybi', _}, _Sock, _SocketMod, Headers,
+	  {_Path, _Q, _Origin, _Host, _Port}) ->
+    {_, Key} = lists:keyfind(<<"Sec-Websocket-Key">>, 1,
+			     Headers),
+    Hash = jlib:encode_base64(
+             sha:sha1(<<Key/binary, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11">>)),
+    [<<"HTTP/1.1 101 Switching Protocols\r\n">>,
+     <<"Upgrade: websocket\r\n">>,
+     <<"Connection: Upgrade\r\n">>,
+     <<"Sec-WebSocket-Accept: ">>, Hash, <<"\r\n\r\n">>].
 
-% Function: List
-% Description: Builds the challenge for a handshake response.
-% Code portions from Sergio Veiga <http://sergioveiga.com/index.php/2010/06/17/websocket-handshake-76-in-erlang/>
-build_challenge({'draft-hixie', 0}, {Key1, Key2, Key3}) ->
-	Ikey1 = [D || D <- Key1, $0 =< D, D =< $9],
-	Ikey2 = [D || D <- Key2, $0 =< D, D =< $9],
-	Blank1 = length([D || D <- Key1, D =:= 32]),
-	Blank2 = length([D || D <- Key2, D =:= 32]),
-	Part1 = list_to_integer(Ikey1) div Blank1,
-	Part2 = list_to_integer(Ikey2) div Blank2,
-	Ckey = <<Part1:4/big-unsigned-integer-unit:8, Part2:4/big-unsigned-integer-unit:8, Key3/binary>>,
-	erlang:md5(Ckey).
-	
-	
-ws_loop(Vsn, HandlerState, Socket, WsHandleLoopPid, SocketMode, WsAutoExit) ->
-	receive
-               {tcp, Socket, Data} ->
-                   %?ERROR_MSG("[WS recv] ~p~n[Buffer state] ~p", [Data, Buffer]),
-                   {NewHandlerState, ToSend} = handle_data(Vsn, HandlerState, Data, Socket, WsHandleLoopPid, SocketMode, WsAutoExit),
-                   lists:foreach(fun(Pkt) ->
-                                        SocketMode:send(Socket, Pkt)
-                                end, ToSend),
-                   ws_loop(Vsn, NewHandlerState, Socket, WsHandleLoopPid, SocketMode, WsAutoExit);                
-		{tcp_closed, Socket} ->
-			?DEBUG("tcp connection was closed, exit", []),
-			% close websocket and custom controlling loop
-			websocket_close(Socket, WsHandleLoopPid, SocketMode, WsAutoExit);
-		{'DOWN', Ref, process, WsHandleLoopPid, Reason} ->
-			case Reason of
-				normal ->
-					%?DEBUG("linked websocket controlling loop stopped.", []);
-					ok;
-				_ ->
-					?ERROR_MSG("linked websocket controlling loop crashed with reason: ~p", [Reason])
+build_challenge({'draft-hixie', 0},
+		{Key1, Key2, Key3}) ->
+    Ikey1 = << <<D>> || <<D>> <= Key1, $0 =< D, D =< $9>>,
+    Ikey2 = << <<D>> || <<D>> <= Key2, $0 =< D, D =< $9>>,
+    Blank1 = byte_size(<< <<D>> || <<D>> <= Key1, D =:= 32>>),
+    Blank2 = byte_size(<< <<D>> || <<D>> <= Key2, D =:= 32>>),
+    Part1 = jlib:binary_to_integer(Ikey1) div Blank1,
+    Part2 = jlib:binary_to_integer(Ikey2) div Blank2,
+    Ckey = <<Part1:4/big-unsigned-integer-unit:8,
+	     Part2:4/big-unsigned-integer-unit:8, Key3/binary>>,
+    erlang:md5(Ckey).
+
+ws_loop(Vsn, HandlerState, Socket, WsHandleLoopPid,
+	SocketMode, WsAutoExit) ->
+    receive
+      {tcp, Socket, Data} ->
+	  {NewHandlerState, ToSend} = handle_data(Vsn,
+						  HandlerState, Data, Socket,
+						  WsHandleLoopPid, SocketMode,
+						  WsAutoExit),
+	  lists:foreach(fun (Pkt) -> SocketMode:send(Socket, Pkt)
 			end,
-			% demonitor
-			erlang:demonitor(Ref),
-			% close websocket and custom controlling loop
-			websocket_close(Socket, WsHandleLoopPid, SocketMode, WsAutoExit);
-		{send, Data} ->
-			%?DEBUG("sending data to websocket: ~p", [Data]),
-			SocketMode:send(Socket, encode_frame(Vsn, Data)),
-			ws_loop(Vsn, HandlerState, Socket, WsHandleLoopPid, SocketMode, WsAutoExit);
-		shutdown ->
-			?DEBUG("shutdown request received, closing websocket with pid ~p", [self()]),
-			% close websocket and custom controlling loop
-			websocket_close(Socket, WsHandleLoopPid, SocketMode, WsAutoExit);
-		_Ignored ->
-			?WARNING_MSG("received unexpected message, ignoring: ~p", [_Ignored]),
-			ws_loop(Vsn, HandlerState, Socket, WsHandleLoopPid, SocketMode, WsAutoExit)
-	end.
+			ToSend),
+	  ws_loop(Vsn, NewHandlerState, Socket, WsHandleLoopPid,
+		  SocketMode, WsAutoExit);
+      {tcp_closed, Socket} ->
+	  ?DEBUG("tcp connection was closed, exit", []),
+	  websocket_close(Socket, WsHandleLoopPid, SocketMode,
+			  WsAutoExit);
+      {'DOWN', Ref, process, WsHandleLoopPid, Reason} ->
+	  case Reason of
+	    normal ->
+		%?DEBUG("linked websocket controlling loop stopped.", []);
+		ok;
+	    _ ->
+		?ERROR_MSG("linked websocket controlling loop crashed "
+			   "with reason: ~p",
+			   [Reason])
+	  end,
+	  erlang:demonitor(Ref),
+	  websocket_close(Socket, WsHandleLoopPid, SocketMode,
+			  WsAutoExit);
+      {send, Data} ->
+	  SocketMode:send(Socket, encode_frame(Vsn, Data)),
+	  ws_loop(Vsn, HandlerState, Socket, WsHandleLoopPid,
+		  SocketMode, WsAutoExit);
+      shutdown ->
+	  ?DEBUG("shutdown request received, closing websocket "
+		 "with pid ~p",
+		 [self()]),
+	  websocket_close(Socket, WsHandleLoopPid, SocketMode,
+			  WsAutoExit);
+      _Ignored ->
+	  ?WARNING_MSG("received unexpected message, ignoring: ~p",
+		       [_Ignored]),
+	  ws_loop(Vsn, HandlerState, Socket, WsHandleLoopPid,
+		  SocketMode, WsAutoExit)
+    end.
 
 encode_frame({'draft-hybi', _}, Data, Opcode) ->
     case byte_size(Data) of
-        S1 when S1 < 126 ->
-            <<1:1, 0:3, Opcode:4, 0:1, S1:7, Data/binary>>;
-        S2 when S2 < 65536 ->
-            <<1:1, 0:3, Opcode:4, 0:1, 126:7, S2:16, Data/binary>>;
-        S3 ->
-            <<1:1, 0:3, Opcode:4, 0:1, 127:7, S3:64, Data/binary>>
+      S1 when S1 < 126 ->
+	  <<1:1, 0:3, Opcode:4, 0:1, S1:7, Data/binary>>;
+      S2 when S2 < 65536 ->
+	  <<1:1, 0:3, Opcode:4, 0:1, 126:7, S2:16, Data/binary>>;
+      S3 ->
+	  <<1:1, 0:3, Opcode:4, 0:1, 127:7, S3:64, Data/binary>>
     end.
 
-encode_frame({'draft-hybi', _}=Vsn, Data) ->
+encode_frame({'draft-hybi', _} = Vsn, Data) ->
     encode_frame(Vsn, Data, 1);
-encode_frame(_, Data) ->
-    <<0, Data/binary, 255>>.
+encode_frame(_, Data) -> <<0, Data/binary, 255>>.
 
 process_hixie_68(none, Data) ->
     process_hixie_68({false, <<>>}, Data);
-process_hixie_68({false, <<>>}, <<0,T/binary>>) ->
+process_hixie_68({false, <<>>}, <<0, T/binary>>) ->
     process_hixie_68({true, <<>>}, T);
-process_hixie_68(L, <<>>) ->
-    {L, [], []};
-process_hixie_68({_, L}, <<255,T/binary>>) ->
+process_hixie_68(L, <<>>) -> {L, [], []};
+process_hixie_68({_, L}, <<255, T/binary>>) ->
     {L2, Recv, Send} = process_hixie_68({false, <<>>}, T),
-    {L2, [L|Recv], Send};
+    {L2, [L | Recv], Send};
 process_hixie_68({true, L}, <<H/utf8, T/binary>>) ->
     process_hixie_68({true, <<L/binary, H>>}, T).
 
--record(hybi_8_state, {mask=none, offset=0, left, final_frame=true, opcode, unprocessed = <<>>, unmasked = <<>>, unmasked_msg = <<>>}).
+-record(hybi_8_state,
+	{mask = none, offset = 0, left, final_frame = true,
+	 opcode, unprocessed = <<>>, unmasked = <<>>,
+	 unmasked_msg = <<>>}).
 
-decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 0:1, Len:7, Data/binary>>) when Len < 126 ->
+decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 0:1,
+		       Len:7, Data/binary>>)
+    when Len < 126 ->
     {Len, Final, Opcode, none, Data};
-decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 0:1, 126:7, Len:16/integer, Data/binary>>) ->
+decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 0:1,
+		       126:7, Len:16/integer, Data/binary>>) ->
     {Len, Final, Opcode, none, Data};
-decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 0:1, 127:7, Len:64/integer, Data/binary>>) ->
+decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 0:1,
+		       127:7, Len:64/integer, Data/binary>>) ->
     {Len, Final, Opcode, none, Data};
-decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 1:1, Len:7, Mask:4/binary, Data/binary>>) when Len < 126 ->
+decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 1:1,
+		       Len:7, Mask:4/binary, Data/binary>>)
+    when Len < 126 ->
     {Len, Final, Opcode, Mask, Data};
-decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 1:1, 126:7, Len:16/integer, Mask:4/binary, Data/binary>>) ->
+decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 1:1,
+		       126:7, Len:16/integer, Mask:4/binary, Data/binary>>) ->
     {Len, Final, Opcode, Mask, Data};
-decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 1:1, 127:7, Len:64/integer, Mask:4/binary, Data/binary>>) ->
+decode_hybi_8_header(<<Final:1, _:3, Opcode:4, 1:1,
+		       127:7, Len:64/integer, Mask:4/binary, Data/binary>>) ->
     {Len, Final, Opcode, Mask, Data};
-decode_hybi_8_header(_) ->
-    none.
+decode_hybi_8_header(_) -> none.
 
 unmask_hybi_8_int(Offset, _, <<>>, Acc) ->
     {Acc, Offset};
-unmask_hybi_8_int(0, <<M:32>>=Mask, <<N:32, Rest/binary>>, Acc) ->
-    unmask_hybi_8_int(0, Mask, Rest, <<Acc/binary, (M bxor N):32>>);
-unmask_hybi_8_int(0, <<M:8, _/binary>>=Mask, <<N:8, Rest/binary>>, Acc) ->
-    unmask_hybi_8_int(1, Mask, Rest, <<Acc/binary, (M bxor N):8>>);
-unmask_hybi_8_int(1, <<_:8, M:8, _/binary>>=Mask, <<N:8, Rest/binary>>, Acc) ->
-    unmask_hybi_8_int(2, Mask, Rest, <<Acc/binary, (M bxor N):8>>);
-unmask_hybi_8_int(2, <<_:16, M:8, _/binary>>=Mask, <<N:8, Rest/binary>>, Acc) ->
-    unmask_hybi_8_int(3, Mask, Rest, <<Acc/binary, (M bxor N):8>>);
-unmask_hybi_8_int(3, <<_:24, M:8>>=Mask, <<N:8, Rest/binary>>, Acc) ->
-    unmask_hybi_8_int(0, Mask, Rest, <<Acc/binary, (M bxor N):8>>).
+unmask_hybi_8_int(0, <<M:32>> = Mask,
+		  <<N:32, Rest/binary>>, Acc) ->
+    unmask_hybi_8_int(0, Mask, Rest,
+		      <<Acc/binary, (M bxor N):32>>);
+unmask_hybi_8_int(0, <<M:8, _/binary>> = Mask,
+		  <<N:8, Rest/binary>>, Acc) ->
+    unmask_hybi_8_int(1, Mask, Rest,
+		      <<Acc/binary, (M bxor N):8>>);
+unmask_hybi_8_int(1, <<_:8, M:8, _/binary>> = Mask,
+		  <<N:8, Rest/binary>>, Acc) ->
+    unmask_hybi_8_int(2, Mask, Rest,
+		      <<Acc/binary, (M bxor N):8>>);
+unmask_hybi_8_int(2, <<_:16, M:8, _/binary>> = Mask,
+		  <<N:8, Rest/binary>>, Acc) ->
+    unmask_hybi_8_int(3, Mask, Rest,
+		      <<Acc/binary, (M bxor N):8>>);
+unmask_hybi_8_int(3, <<_:24, M:8>> = Mask,
+		  <<N:8, Rest/binary>>, Acc) ->
+    unmask_hybi_8_int(0, Mask, Rest,
+		      <<Acc/binary, (M bxor N):8>>).
 
-unmask_hybi_8(#hybi_8_state{mask=none}=State, Data) ->
+unmask_hybi_8(#hybi_8_state{mask = none} = State,
+	      Data) ->
     {State, Data};
-unmask_hybi_8(#hybi_8_state{mask=Mask, offset=Offset}=State, Data) ->
-    {Unmasked, NewOffset} = unmask_hybi_8_int(Offset, Mask, Data, <<>>),
-    {State#hybi_8_state{offset=NewOffset}, Unmasked}.
-
+unmask_hybi_8(#hybi_8_state{mask = Mask,
+			    offset = Offset} =
+		  State,
+	      Data) ->
+    {Unmasked, NewOffset} = unmask_hybi_8_int(Offset, Mask,
+					      Data, <<>>),
+    {State#hybi_8_state{offset = NewOffset}, Unmasked}.
 
 process_hybi_8(none, Data) ->
     process_hybi_8(#hybi_8_state{}, Data);
-process_hybi_8(State, <<>>) ->
-    {State, [], []};
-process_hybi_8(#hybi_8_state{unprocessed=none, unmasked=UnmaskedPre, left=Left}=State,
-                Data) when byte_size(Data) < Left ->
+process_hybi_8(State, <<>>) -> {State, [], []};
+process_hybi_8(#hybi_8_state{unprocessed = none,
+			     unmasked = UnmaskedPre, left = Left} =
+		   State,
+	       Data)
+    when byte_size(Data) < Left ->
     {State2, Unmasked} = unmask_hybi_8(State, Data),
-    {State2#hybi_8_state{left=Left-byte_size(Data), unmasked=[UnmaskedPre, Unmasked]}, [], []};
-process_hybi_8(#hybi_8_state{unprocessed=none, unmasked=UnmaskedPre, opcode=Opcode,
-                              final_frame=Final, left=Left, unmasked_msg=UnmaskedMsg}=State, Data) ->
-    {_State, Unmasked} = unmask_hybi_8(State, binary_part(Data, 0, Left)),
-    Unprocessed = binary_part(Data, Left, byte_size(Data)-Left),
+    {State2#hybi_8_state{left = Left - byte_size(Data),
+			 unmasked = [UnmaskedPre, Unmasked]},
+     [], []};
+process_hybi_8(#hybi_8_state{unprocessed = none,
+			     unmasked = UnmaskedPre, opcode = Opcode,
+			     final_frame = Final, left = Left,
+			     unmasked_msg = UnmaskedMsg} =
+		   State,
+	       Data) ->
+    <<ToProcess:(Left)/binary, Unprocessed/binary>> = Data,
+    {_State, Unmasked} = unmask_hybi_8(State, ToProcess),
     case Final of
-        true ->
-            {State3, Recv, Send} = process_hybi_8(#hybi_8_state{}, Unprocessed),
-            case Opcode of
-                9 ->
-                    Frame = encode_frame({'draft-hybi', 8}, Unprocessed, 10),
-                    {State3#hybi_8_state{unmasked_msg=UnmaskedMsg}, Recv, [Frame|Send]};
-                X when X < 3 ->
-                    {State3, [iolist_to_binary([UnmaskedMsg, UnmaskedPre, Unmasked])|Recv], Send};
-                _ ->
-                    {State3#hybi_8_state{unmasked_msg=UnmaskedMsg}, Recv, Send}                     
-            end;
-        _ ->
-            process_hybi_8(#hybi_8_state{unmasked_msg=[UnmaskedMsg, UnmaskedPre, Unmasked]}, Unprocessed)
+      true ->
+	  {State3, Recv, Send} = process_hybi_8(#hybi_8_state{},
+						Unprocessed),
+	  case Opcode of
+	    9 ->
+		Frame = encode_frame({'draft-hybi', 8}, Unprocessed,
+				     10),
+		{State3#hybi_8_state{unmasked_msg = UnmaskedMsg}, Recv,
+		 [Frame | Send]};
+	    X when X < 3 ->
+		{State3,
+		 [iolist_to_binary([UnmaskedMsg, UnmaskedPre, Unmasked])
+		  | Recv],
+		 Send};
+	    _ ->
+		{State3#hybi_8_state{unmasked_msg = UnmaskedMsg}, Recv,
+		 Send}
+	  end;
+      _ ->
+	  process_hybi_8(#hybi_8_state{unmasked_msg =
+					   [UnmaskedMsg, UnmaskedPre,
+					    Unmasked]},
+			 Unprocessed)
     end;
-process_hybi_8(#hybi_8_state{unprocessed= <<>>}=State, Data) ->
+process_hybi_8(#hybi_8_state{unprocessed = <<>>} =
+		   State,
+	       Data) ->
     case decode_hybi_8_header(Data) of
-        none ->
-            {State#hybi_8_state{unprocessed=Data}, [], []};
-        {Len, Final, Opcode, Mask, Rest} ->
-            process_hybi_8(State#hybi_8_state{mask=Mask, final_frame=Final==1,
-                                               left=Len, opcode=Opcode,
-                                               unprocessed=none}, Rest)
+      none ->
+	  {State#hybi_8_state{unprocessed = Data}, [], []};
+      {Len, Final, Opcode, Mask, Rest} ->
+	  process_hybi_8(State#hybi_8_state{mask = Mask,
+					    final_frame = Final == 1,
+					    left = Len, opcode = Opcode,
+					    unprocessed = none},
+			 Rest)
     end;
-process_hybi_8(#hybi_8_state{unprocessed=UnprocessedPre}=State, Data) ->
-    process_hybi_8(State#hybi_8_state{unprocessed = <<>>}, <<UnprocessedPre/binary, Data/binary>>).
+process_hybi_8(#hybi_8_state{unprocessed =
+				 UnprocessedPre} =
+		   State,
+	       Data) ->
+    process_hybi_8(State#hybi_8_state{unprocessed = <<>>},
+		   <<UnprocessedPre/binary, Data/binary>>).
 
-
-% Buffering and data handling
-handle_data({'draft-hybi', _}, State, Data, _Socket, WsHandleLoopPid, _SocketMode, _WsAutoExit) ->
+handle_data({'draft-hybi', _}, State, Data, _Socket,
+	    WsHandleLoopPid, _SocketMode, _WsAutoExit) ->
     {NewState, Recv, Send} = process_hybi_8(State, Data),
-    lists:foreach(fun(El) ->
-                          WsHandleLoopPid ! {browser, El}
-                  end, Recv),
+    lists:foreach(fun (El) ->
+			  WsHandleLoopPid ! {browser, El}
+		  end,
+		  Recv),
     {NewState, Send};
-handle_data(_Vsn, State, Data, _Socket, WsHandleLoopPid, _SocketMode, _WsAutoExit) ->
+handle_data(_Vsn, State, Data, _Socket, WsHandleLoopPid,
+	    _SocketMode, _WsAutoExit) ->
     {NewState, Recv, Send} = process_hixie_68(State, Data),
-    lists:foreach(fun(El) ->
-                          WsHandleLoopPid ! {browser, El}
-                  end, Recv),
-    {NewState, Send};
-%% Invalid input
-handle_data(_Vsn, _State, _Data, Socket, WsHandleLoopPid, SocketMode, WsAutoExit) ->
-    websocket_close(Socket, WsHandleLoopPid, SocketMode, WsAutoExit).
+    lists:foreach(fun (El) ->
+			  WsHandleLoopPid ! {browser, El}
+		  end,
+		  Recv),
+    {NewState, Send}.
 
-% Close socket and custom handling loop dependency
-websocket_close(Socket, WsHandleLoopPid, SocketMode, WsAutoExit) ->
-	case WsAutoExit of
-		true ->
-			% kill custom handling loop process
-			exit(WsHandleLoopPid, kill);
-		false ->
-			% the killing of the custom handling loop process is handled in the loop itself -> send event
-			WsHandleLoopPid ! closed
-	end,
-	% close main socket
-	SocketMode:close(Socket).
+websocket_close(Socket, WsHandleLoopPid, SocketMode,
+		WsAutoExit) ->
+    case WsAutoExit of
+      true ->
+	  % kill custom handling loop process
+	  exit(WsHandleLoopPid, kill);
+      false -> WsHandleLoopPid ! closed
+    end,
+    SocketMode:close(Socket).