HTML5 Web Sockets support.

src/Makefile

@@ -42,7 +42,8 @@ MODULES=yaws \
 	yaws_sendfile yaws_sendfile_compat \
 	yaws_sup_restarts \
 	yaws_stats \
-	yaws_multipart
+	yaws_multipart \
+	yaws_websockets
 
 
 

src/yaws_api.erl

@@ -36,6 +36,8 @@
          stream_chunk_end/1]).
 -export([stream_process_deliver/2, stream_process_deliver_chunk/2,
          stream_process_deliver_final_chunk/2, stream_process_end/2]).
+-export([websocket_send/2, websocket_receive/1,
+         websocket_unframe_data/1, websocket_setopts/2]).
 -export([new_cookie_session/1, new_cookie_session/2, new_cookie_session/3, 
          cookieval_to_opaque/1, request_url/1,
          print_cookie_sessions/0,
@@ -866,6 +868,40 @@ stream_process_end(Sock, YawsPid) ->
     gen_tcp:controlling_process(Sock, YawsPid),
     YawsPid ! endofstreamcontent.
 
+
+websocket_send(Socket, IoList) ->
+    DataFrame = [0, IoList, 255],
+    case Socket of
+	{sslsocket,_,_} ->
+	    ssl:send(Socket, DataFrame);
+	_ ->
+	    gen_tcp:send(Socket, DataFrame)
+    end.
+
+websocket_receive(Socket) ->
+    R = case Socket of
+	    {sslsocket,_,_} ->
+		ssl:recv(Socket, 0);
+	    _ ->
+		gen_tcp:recv(Socket, 0)
+	end,
+    case R of
+	{ok, DataFrames} ->
+	    ReceivedMsgs = yaws_websockets:unframe_all(DataFrames, []),
+	    {ok, ReceivedMsgs};
+	_ -> R
+    end.
+
+websocket_unframe_data(DataFrameBin) ->
+    {ok, Msg, <<>>} = yaws_websockets:unframe_one(DataFrameBin),
+    Msg.
+
+websocket_setopts({sslsocket,_,_}=Socket, Opts) ->
+    ssl:setopts(Socket, Opts);
+websocket_setopts(Socket, Opts) ->
+    inet:setopts(Socket, Opts).
+
+
 %% Return new cookie string
 new_cookie_session(Opaque) ->
     yaws_session_server:new_session(Opaque).

src/yaws_server.erl

@@ -922,12 +922,16 @@ acceptor0(GS, Top) ->
                     ok
             end,
             Res = (catch aloop(Client, GS,  0)),
-            if
-                GS#gs.ssl == nossl ->
-                    gen_tcp:close(Client);
-                GS#gs.ssl == ssl ->
-                    ssl:close(Client)
-            end,
+	    case yaws:outh_get_doclose() of
+		false -> ok;
+		true ->
+		    if
+			GS#gs.ssl == nossl ->
+			    gen_tcp:close(Client);
+			GS#gs.ssl == ssl ->
+			    ssl:close(Client)
+		    end
+	    end,
             case Res of
                 {ok, Int} when is_integer(Int) ->
                     Top ! {self(), done_client, Int};
@@ -2347,6 +2351,12 @@ deliver_dyn_part(CliSock,                       % essential params
             Priv = deliver_accumulated(Arg, CliSock,
                                        no, undefined, stream),
             wait_for_streamcontent_pid(Priv, CliSock, Pid);
+        {websocket, OwnerPid, SocketMode} ->
+			%% The handshake passes control over the socket to OwnerPid
+			%% and terminates the Yaws worker!
+            yaws_websockets:handshake(Arg, OwnerPid, SocketMode)
+			%% this point is never reached
+			;
         _ ->
             DeliverCont(Arg)
     end.
@@ -2767,6 +2777,10 @@ handle_out_reply({streamcontent_from_pid, MimeType, Pid},
     yaws:outh_set_content_type(MimeType),
     {streamcontent_from_pid, MimeType, Pid};
 
+handle_out_reply({websocket, _OwnerPid, _SocketMode}=Reply,
+				_LineNo,_YawsFile, _UT, _ARG) ->
+	Reply;
+
 handle_out_reply({header, H},  _LineNo, _YawsFile, _UT, _ARG) ->
     yaws:accumulate_header(H);
 

src/yaws_websockets.erl

@@ -0,0 +1,122 @@
+%%%----------------------------------------------------------------------
+%%% File    : yaws_websockets.erl
+%%% Author  : Davide Marquês <nesrait@gmail.com>
+%%% Purpose : 
+%%% Created :  18 Dec 2009 by Davide Marquês <nesrait@gmail.com>
+%%% Modified: 
+%%%----------------------------------------------------------------------
+
+-module(yaws_websockets).
+-author('nesrait@gmail.com').
+
+-include("../include/yaws.hrl").
+-include("../include/yaws_api.hrl").
+-include("yaws_debug.hrl").
+
+-include_lib("kernel/include/file.hrl").
+-export([handshake/3, unframe_one/1, unframe_all/2]).
+
+handshake(Arg, ContentPid, SocketMode) ->
+    CliSock = Arg#arg.clisock,
+    case get_origin_header(Arg#arg.headers) of
+	undefined ->
+	    %% Yaws will take care of closing the socket
+	    ContentPid ! discard;
+	Origin ->
+	    Host = (Arg#arg.headers)#headers.host,
+	    {abs_path, Path} = (Arg#arg.req)#http_request.path,
+	    %% TODO: Support for wss://
+	    WebSocketLocation = "ws://" ++ Host ++ Path,
+	    Handshake =
+		["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: ", WebSocketLocation, "\r\n",
+		 "\r\n"],
+	    SC = get(sc),
+	    case SC#sconf.ssl of
+		undefined ->
+		    gen_tcp:send(CliSock, Handshake),
+		    inet:setopts(CliSock, [{packet, raw}, {active, SocketMode}]),
+		    TakeOverResult =
+			gen_tcp:controlling_process(CliSock, ContentPid);
+		_ ->
+		    ssl:send(CliSock, Handshake),
+		    ssl:setopts(CliSock, [{packet, raw}, {active, SocketMode}]),
+		    TakeOverResult =
+			ssl:controlling_process(CliSock, ContentPid)
+	    end,
+	    case TakeOverResult of
+		ok ->
+		    %% Make sure that Yaws doesn't close the socket!
+		    put(outh, (get(outh))#outh{doclose = false}),
+		    ContentPid ! {ok, CliSock};
+		{error, Reason} ->
+		    ContentPid ! discard,
+		    exit({websocket, Reason})
+	    end
+    end,
+    exit(normal).
+
+
+%% This should take care of all the Data Framing scenarios specified in
+%% http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-66#page-26
+unframe_one(DataFrames) ->
+    <<Type, _/bitstring>> = DataFrames,
+    case Type of
+	T when (T =< 127) ->
+	    %% {ok, FF_Ended_Frame} = re:compile("^.(.*)\\xFF(.*?)", [ungreedy]),
+	    FF_Ended_Frame = {re_pattern,2,0,
+			      <<69,82,67,80,71,0,0,0,16,2,0,0,5,0,0,0,2,0,0,0,0,0,255,2,40,
+			       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,93,0,27,25,12,94,0,7,0,1,57,
+			       12,84,0,7,27,255,94,0,7,0,2,56,12,84,0,7,84,0,27,0>>},
+	    {match, [Data, NextFrame]} =
+		re:run(DataFrames, FF_Ended_Frame,
+		       [{capture, all_but_first, binary}]),
+	    {ok, Data, NextFrame};
+
+	_ -> %% Type band 16#80 =:= 16#80
+	    {Length, LenBytes} = unpack_length(DataFrames, 0, 0),
+	    <<_, _:LenBytes/bytes, Data:Length/bytes,
+	     NextFrame/bitstring>> = DataFrames,
+	    {ok, Data, NextFrame}
+    end.
+
+unframe_all(<<>>, Acc) ->
+    lists:reverse(Acc);
+unframe_all(DataFramesBin, Acc) ->
+    {ok, Msg, Rem} = unframe_one(DataFramesBin),
+    unframe_all(Rem, [Msg|Acc]).
+
+
+%% Internal functions
+get_origin_header(#headers{other=L}) ->
+    lists:foldl(fun({http_header,_,K0,_,V}, undefined) ->
+                        K = case is_atom(K0) of
+                                true ->
+                                    atom_to_list(K0);
+                                false ->
+                                    K0
+                            end,
+                        case string:to_lower(K) of
+                            "origin" ->
+                                V;
+                            _ ->
+                                undefined
+                        end;
+                   (_, Acc) ->
+                        Acc
+                end, undefined, L).
+
+unpack_length(Binary, LenBytes, Length) ->
+    <<_, _:LenBytes/bytes, B, _/bitstring>> = Binary,
+    B_v = B band 16#7F,
+    NewLength = (Length * 128) + B_v,
+    case B band 16#80 of
+	16#80 ->
+	    unpack_length(Binary, LenBytes + 1, NewLength);
+	0 ->
+	    {NewLength, LenBytes + 1}
+    end.
+

www/websockets_example.yaws

@@ -0,0 +1,157 @@
+
+<erl>
+
+out(A) -> 
+    case get_upgrade_header(A#arg.headers) of 
+	undefined ->
+	    serve_html_page(A);
+	"WebSocket" ->
+	    WebSocketOwner = spawn(fun() -> websocket_owner() end),
+	    {websocket, WebSocketOwner, passive}
+    end.
+
+
+websocket_owner() ->
+    receive
+	{ok, WebSocket} ->
+	    %% This is how we read messages (plural!!) from websockets on passive mode
+	    case yaws_api:websocket_receive(WebSocket) of
+		{error,closed} ->
+		    io:format("The websocket got disconnected right from the start. "
+			      "This wasn't supposed to happen!!~n");
+		{ok, Messages} ->
+		    case Messages of
+			[<<"client-connected">>] ->
+			    yaws_api:websocket_setopts(WebSocket, [{active, true}]),
+			    echo_server(WebSocket);
+			Other ->
+			    io:format("websocket_owner got: ~p. Terminating~n", [Other])
+		    end
+	    end;
+	_ -> ok
+    end.
+
+
+echo_server(WebSocket) ->
+    receive
+	{tcp, WebSocket, DataFrame} ->
+	    Data = yaws_api:websocket_unframe_data(DataFrame),
+	    io:format("Got data from Websocket: ~p~n", [Data]),
+            yaws_api:websocket_send(WebSocket, Data), 
+            echo_server(WebSocket);
+	{tcp_closed, WebSocket} ->
+	    io:format("Websocket closed. Terminating echo_server...~n");
+	Any ->
+	    io:format("echo_server received msg:~p~n", [Any]),
+	    echo_server(WebSocket)
+    end.
+
+get_upgrade_header(#headers{other=L}) ->
+    lists:foldl(fun({http_header,_,K0,_,V}, undefined) ->
+                        K = case is_atom(K0) of
+                                true ->
+                                    atom_to_list(K0);
+                                false ->
+                                    K0
+                            end,
+                        case string:to_lower(K) of
+                            "upgrade" ->
+                                V;
+                            _ ->
+                                undefined
+                        end;
+                   (_, Acc) ->
+                        Acc
+                end, undefined, L).
+
+serve_html_page(A) ->
+    Host = (A#arg.headers)#headers.host,
+    {abs_path, Path} = (A#arg.req)#http_request.path,
+    WebSocketLocation = Host ++ Path,
+    io:format("WebSocketLocation: ~p ~n", [WebSocketLocation]),
+    Body = html_body(WebSocketLocation),
+    {content, "text/html", Body}.
+
+%% this html was copied from the basic example in
+%% http://github.com/davebryson/erlang_websocket/
+html_body(WebSocketLocation) ->
+"<html>
+<head> 
+  <title>Basic WebSocket Example</title> 
+  <script type=\"text/javascript\"> 
+     if (!window.WebSocket)
+        alert(\"WebSocket not supported by this browser\");
+
+    // Get an Element
+    function $() { return document.getElementById(arguments[0]); }
+    // Get the value of an Element
+    function $F() { return document.getElementById(arguments[0]).value; }
+
+    var client = {
+        connect: function(){
+         this._ws=new WebSocket(\"ws://" ++ WebSocketLocation ++ "\");
+         this._ws.onopen=this._onopen;
+         this._ws.onmessage=this._onmessage;
+         this._ws.onclose=this._onclose;
+        },
+        _onopen: function(){
+          $('connect').className='hidden';
+          $('connected').className='';
+          $('phrase').focus();
+          client._send('client-connected');
+       },
+        _send: function(message){
+           if (this._ws)
+            this._ws.send(message);
+        },
+       chat: function(text) {
+          if (text != null && text.length>0 )
+            client._send(text);
+        },
+        _onmessage: function(m) {
+          if (m.data){
+            var text = m.data; 
+            var msg=$('msgs');
+            var spanText = document.createElement('span');
+            spanText.className='text';
+            spanText.innerHTML=text;
+            var lineBreak = document.createElement('br');
+            msg.appendChild(spanText);
+            msg.appendChild(lineBreak);
+            msg.scrollTop = msg.scrollHeight - msg.clientHeight;   
+          }
+        },
+        _onclose: function(m) {
+          this._ws=null;
+          $('connect').className='';
+          $('connected').className='hidden';
+          $('msg').innerHTML='';
+        }
+    };
+  </script> 
+  <style type='text/css'> 
+    div.hidden { display: none; }
+  </style> 
+
+</head> 
+<body> 
+  <h1>Basic Echo Example</h1> 
+  <div id=\"msgs\"></div> 
+  <div id=\"connect\"> 
+     <input id='cA' class='button' type='submit' name='connect' value='Connect'/> 
+  </div> 
+  <br/> 
+  <div id=\"connected\" class=\"hidden\"> 
+    Say Something:&nbsp;<input id='phrase' type='text'/> 
+    <input id='sendB' class='button' type='submit' name='connect' value='Send'/> 
+  </div> 
+
+  <script type='text/javascript'> 
+    $('cA').onclick = function(event) { client.connect(); return false; };
+    $('sendB').onclick = function(event) { client.chat($F('phrase')); $('phrase').value=''; return false; };	
+ </script> 
+  </body> 
+</html>".
+
+</erl>
+