Unify paths for handling websocket and regular http requests

This allow to easily produce html output from error paths in websocket code,
and this ability is used to produce informational page when regular http
request is directed to websocket url. Additionally HEAD and OPTIONS request
are now handled correctly.

5 files changed, 170 insertions, 106 deletions

diff --git a/src/web/ejabberd_http.erl b/src/web/ejabberd_http.erl
index a9dbf7a44..f581c2060 100644
--- a/src/web/ejabberd_http.erl
+++ b/src/web/ejabberd_http.erl
@@ -332,61 +332,36 @@ get_transfer_protocol(SockMod, HostPort) ->
 %% matches the requested URL path, and pass control to it.  If none is
 %% found, answer with HTTP 404.
 
-process([], _) -> ejabberd_web:error(not_found);
-process(Handlers, #ws{} = Ws) ->
-    [{HandlerPathPrefix, HandlerModule, HandlerOpts} | HandlersLeft] =
-	Handlers,
-    case lists:prefix(HandlerPathPrefix, Ws#ws.path) or
-	   (HandlerPathPrefix == Ws#ws.path)
-	of
-      true ->
-	  ?DEBUG("~p matches ~p",
-		 [Ws#ws.path, HandlerPathPrefix]),
-	  LocalPath = lists:nthtail(length(HandlerPathPrefix),
-				    Ws#ws.path),
-	  ejabberd_hooks:run(ws_debug, [{LocalPath, Ws}]),
-	  Protocol = case lists:keysearch(protocol, 1,
-					  HandlerOpts)
-			 of
-		       {value, {protocol, P}} -> P;
-		       false -> undefined
-		     end,
-	  Origins = case lists:keysearch(origins, 1, HandlerOpts)
-			of
-		      {value, {origins, O}} -> O;
-		      false -> []
-		    end,
-	  Auth = case lists:keysearch(auth, 1, HandlerOpts) of
-		   {value, {auth, A}} -> A;
-		   false -> undefined
-		 end,
-	  WS2 = Ws#ws{local_path = LocalPath, protocol = Protocol,
-		      acceptable_origins = Origins, auth_module = Auth},
-	  case ejabberd_websocket:is_acceptable(WS2) of
-	    true -> ejabberd_websocket:connect(WS2, HandlerModule);
-	    false -> process(HandlersLeft, Ws)
-	  end;
-      false -> process(HandlersLeft, Ws)
-    end;
-process(Handlers, Request) ->
-    %% Only the first element in the path prefix is checked
-    [{HandlerPathPrefix, HandlerModule} | HandlersLeft] =
-	Handlers,
-    case lists:prefix(HandlerPathPrefix,
-                    Request#request.path)
-	   or (HandlerPathPrefix == Request#request.path)
-	of
-      true ->
-	  ?DEBUG("~p matches ~p",
-		 [Request#request.path, HandlerPathPrefix]),
-	  LocalPath = lists:nthtail(length(HandlerPathPrefix),
-				    Request#request.path),
-            ?DEBUG("~p", [Request#request.headers]),
-	  R = HandlerModule:process(LocalPath, Request),
-	  ejabberd_hooks:run(http_request_debug,
-			     [{LocalPath, Request}]),
-	  R;
-      false -> process(HandlersLeft, Request)
+process([], _, _, _) -> ejabberd_web:error(not_found);
+process(Handlers, Request, Socket, SockMod) ->
+    {HandlerPathPrefix, HandlerModule, HandlerOpts, HandlersLeft} =
+        case Handlers of
+            [{Pfx, Mod} | Tail] ->
+                {Pfx, Mod, [], Tail};
+            [{Pfx, Mod, Opts} | Tail] ->
+                {Pfx, Mod, Opts, Tail}
+        end,
+
+    case (lists:prefix(HandlerPathPrefix, Request#request.path) or
+         (HandlerPathPrefix==Request#request.path)) of
+        true ->
+            ?DEBUG("~p matches ~p", [Request#request.path, HandlerPathPrefix]),
+            %% LocalPath is the path "local to the handler", i.e. if
+            %% the handler was registered to handle "/test/" and the
+            %% requested path is "/test/foo/bar", the local path is
+            %% ["foo", "bar"]
+            LocalPath = lists:nthtail(length(HandlerPathPrefix), Request#request.path),
+            code:ensure_loaded(HandlerModule),
+            R = case erlang:function_exported(HandlerModule, socket_handoff, 5) of
+                    false ->
+                        HandlerModule:process(LocalPath, Request);
+                    _ ->
+                        HandlerModule:socket_handoff(LocalPath, Request, Socket, SockMod, HandlerOpts)
+                end,
+            ejabberd_hooks:run(http_request_debug, [{LocalPath, Request}]),
+            R;
+        false ->
+            process(HandlersLeft, Request, Socket, SockMod)
     end.
 
 extract_path_query(#state{request_method = Method,
@@ -433,7 +408,6 @@ extract_path_query(_State) ->
     false.
 
 process_request(#state{request_method = Method,
-		       request_path = {abs_path, Path},
 		       request_auth = Auth,
 		       request_lang = Lang,
 		       sockmod = SockMod,
@@ -457,38 +431,18 @@ process_request(#state{request_method = Method,
 		end,
 	    XFF = proplists:get_value('X-Forwarded-For', RequestHeaders, []),
 	    IP = analyze_ip_xff(IPHere, XFF, Host),
-	    case Method=:='GET' andalso ejabberd_websocket:check(Path, RequestHeaders) of
-		{true, VSN} ->
-		    {_, Origin} = case lists:keyfind(<<"Sec-Websocket-Origin">>, 1, RequestHeaders) of
-				      false -> lists:keyfind(<<"Origin">>, 1, RequestHeaders);
-				      Value -> Value
-				  end,
-		    Ws = #ws{socket = Socket,
-			     sockmod = SockMod,
-			     ws_autoexit = false,
-			     ip = IP,
-			     path = LPath,
-			     q = LQuery,
-			     vsn = VSN,
-			     host = Host,
-			     port = Port,
-			     origin = Origin,
-			     headers = RequestHeaders
-			    },
-		    process(WebSocketHandlers, Ws);
-		false ->
-		    Request = #request{method = Method,
-				       path = LPath,
-				       q = LQuery,
-				       auth = Auth,
-				       data = Data,
-				       lang = Lang,
-				       host = Host,
-				       port = Port,
-				       tp = TP,
-				       headers = RequestHeaders,
-				       ip = IP},
-                    case process(RequestHandlers, Request) of
+            Request = #request{method = Method,
+                               path = LPath,
+                               q = LQuery,
+                               auth = Auth,
+                               data = Data,
+                               lang = Lang,
+                               host = Host,
+                               port = Port,
+                               tp = TP,
+                               headers = RequestHeaders,
+                               ip = IP},
+            case process(RequestHandlers ++ WebSocketHandlers, Request, Socket, SockMod) of
                         El when is_record(El, xmlel) ->
                             make_xhtml_output(State, 200, [], El);
                         {Status, Headers, El}
@@ -501,8 +455,9 @@ process_request(#state{request_method = Method,
                             make_text_output(State, Status, Headers, Output);
                         {Status, Reason, Headers, Output}
                           when is_binary(Output) or is_list(Output) ->
-                            make_text_output(State, Status, Reason, Headers, Output)
-                    end
+                            make_text_output(State, Status, Reason, Headers, Output);
+                        _ ->
+                            none
 	    end
     end;
 process_request(State) -> make_bad_request(State).
diff --git a/src/web/ejabberd_http.hrl b/src/web/ejabberd_http.hrl
index 51864f447..799f3ce15 100644
--- a/src/web/ejabberd_http.hrl
+++ b/src/web/ejabberd_http.hrl
@@ -46,10 +46,7 @@
          path = []               :: [binary()],
          headers = []            :: [{atom() | binary(), binary()}],
          local_path = []         :: [binary()],
-         q = []                  :: [{binary() | nokey, binary()}],
-         protocol                :: binary(),
-	 acceptable_origins = [] :: [binary()],
-         auth_module             :: atom()}).
+         q = []                  :: [{binary() | nokey, binary()}]}).
 
 -type method() :: 'GET' | 'HEAD' | 'DELETE' | 'OPTIONS' | 'PUT' | 'POST' | 'TRACE'.
 -type protocol() :: http | https.
diff --git a/src/web/ejabberd_http_ws.erl b/src/web/ejabberd_http_ws.erl
index ec3bd4a09..521612d40 100644
--- a/src/web/ejabberd_http_ws.erl
+++ b/src/web/ejabberd_http_ws.erl
@@ -33,7 +33,8 @@
 -export([start/1, start_link/1, init/1, handle_event/3,
 	 handle_sync_event/4, code_change/4, handle_info/3,
 	 terminate/3, send/2, setopts/2, sockname/1, peername/1,
-	 controlling_process/2, become_controller/2, close/1]).
+	 controlling_process/2, become_controller/2, close/1,
+	 socket_handoff/5]).
 
 -include("ejabberd.hrl").
 
@@ -98,6 +99,10 @@ become_controller(FsmRef, C2SPid) ->
 close({http_ws, FsmRef, _IP}) ->
     catch gen_fsm:sync_send_all_state_event(FsmRef, close).
 
+socket_handoff(LocalPath, Request, Socket, SockMod, Opts) ->
+    ejabberd_websocket:socket_handoff(LocalPath, Request, Socket, SockMod,
+                                      Opts, ?MODULE).
+
 %%% Internal
 
 init([WS]) ->
diff --git a/src/web/ejabberd_http_wsjson.erl b/src/web/ejabberd_http_wsjson.erl
index 1881daf22..ff14c96f4 100644
--- a/src/web/ejabberd_http_wsjson.erl
+++ b/src/web/ejabberd_http_wsjson.erl
@@ -35,7 +35,8 @@
 	 handle_sync_event/4, code_change/4, handle_info/3,
 	 terminate/3, send_xml/2, setopts/2, sockname/1,
 	 peername/1, controlling_process/2, become_controller/2,
-	 close/1]).
+	 close/1,
+	 socket_handoff/5]).
 
 -include("ejabberd.hrl").
 
@@ -97,6 +98,10 @@ become_controller(FsmRef, C2SPid) ->
 close({http_ws, FsmRef, _IP}) ->
     catch gen_fsm:sync_send_all_state_event(FsmRef, close).
 
+socket_handoff(LocalPath, Request, Socket, SockMod, Opts) ->
+    ejabberd_websocket:socket_handoff(LocalPath, Request, Socket, SockMod,
+                                      Opts, ?MODULE).
+
 %%% Internal
 
 init([WS]) ->
diff --git a/src/web/ejabberd_websocket.erl b/src/web/ejabberd_websocket.erl
index 78b720b0f..17586701b 100644
--- a/src/web/ejabberd_websocket.erl
+++ b/src/web/ejabberd_websocket.erl
@@ -40,7 +40,7 @@
 
 -author('ecestari@process-one.net').
 
--export([connect/2, check/2, is_acceptable/1]).
+-export([connect/2, check/2, socket_handoff/6]).
 
 -include("ejabberd.hrl").
 
@@ -48,14 +48,25 @@
 
 -include("ejabberd_http.hrl").
 
+-define(CT_XML, {<<"Content-Type">>, <<"text/xml; charset=utf-8">>}).
+-define(CT_PLAIN, {<<"Content-Type">>, <<"text/plain">>}).
+
+-define(AC_ALLOW_ORIGIN, {<<"Access-Control-Allow-Origin">>, <<"*">>}).
+-define(AC_ALLOW_METHODS, {<<"Access-Control-Allow-Methods">>, <<"GET, OPTIONS">>}).
+-define(AC_ALLOW_HEADERS, {<<"Access-Control-Allow-Headers">>, <<"Content-Type">>}).
+-define(AC_MAX_AGE, {<<"Access-Control-Max-Age">>, <<"86400">>}).
+
+-define(OPTIONS_HEADER, [?CT_PLAIN, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_METHODS,
+                          ?AC_ALLOW_HEADERS, ?AC_MAX_AGE]).
+-define(HEADER, [?CT_XML, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_HEADERS]).
+
 check(_Path, Headers) ->
     VsnSupported = [{'draft-hybi', 8}, {'draft-hybi', 13},
 		    {'draft-hixie', 0}, {'draft-hixie', 68}],
     check_websockets(VsnSupported, Headers).
 
-is_acceptable(#ws{origin = Origin, protocol = Protocol,
-		  headers = Headers, acceptable_origins = Origins,
-		  auth_module = undefined}) ->
+is_acceptable(_LocalPath, Origin, _IP, _Q, Headers, Protocol, Origins,
+              undefined) ->
     ClientProtocol = find_subprotocol(Headers),
     case {(Origins == []) or lists:member(Origin, Origins),
 	  ClientProtocol, Protocol}
@@ -68,13 +79,104 @@ is_acceptable(#ws{origin = Origin, protocol = Protocol,
       {_, false, _} -> true;
       {_, P, P} -> true;
       _ = E ->
-	  ?INFO_MSG("Wrong protocol requested : ~p", [E]), false
+	  ?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(LocalPath, Origin, IP, Q, Headers, Protocol, _Origins,
+              AuthModule) ->
+  AuthModule:is_acceptable(LocalPath, Q, Origin, Protocol, IP, Headers).
+
+socket_handoff(LocalPath, #request{method = 'GET', ip = IP, q = Q, path = Path,
+                                   headers = Headers, host = Host, port = Port},
+               Socket, SockMod, Opts, HandlerModule) ->
+    {_, Origin} = case lists:keyfind(<<"Sec-Websocket-Origin">>, 1, Headers) of
+                      false ->
+                          case lists:keyfind(<<"Origin">>, 1, Headers) of
+                              false -> {value, undefined};
+                              Value2 -> Value2
+                          end;
+                      Value -> Value
+                  end,
+    case Origin of
+        undefined ->
+            {200, ?HEADER, get_human_html_xmlel()};
+        _ ->
+            Protocol = case lists:keysearch(protocol, 1, Opts) of
+                           {value, {protocol, P}} -> P;
+                           false -> undefined
+                       end,
+            Origins =  case lists:keysearch(origins, 1, Opts) of
+                           {value, {origins, O}} -> O;
+                           false -> []
+                       end,
+            Auth =  case lists:keysearch(auth, 1, Opts) of
+                        {value, {auth, A}} -> A;
+                        false -> undefined
+                    end,
+            case is_acceptable(LocalPath, Origin, IP, Q, Headers, Protocol, Origins, Auth) of
+                true ->
+                    case check(LocalPath, Headers) of
+                        {true, Vsn} ->
+                            WS = #ws{vsn = Vsn,
+                                     socket = Socket,
+                                     sockmod = SockMod,
+                                     ws_autoexit = false,
+                                     ip = IP,
+                                     origin = Origin,
+                                     q = Q,
+                                     host = Host,
+                                     port = Port,
+                                     path = Path,
+                                     headers = Headers,
+                                     local_path = LocalPath},
+
+                            connect(WS, HandlerModule);
+                        _ ->
+                            {200, ?HEADER, get_human_html_xmlel()}
+                    end;
+                _ ->
+                    {403, ?HEADER, #xmlel{name = <<"h1">>,
+                                          children = [{xmlcdata, <<"403 Forbiden">>}]}}
+            end
+    end;
+socket_handoff(_, #request{method = 'OPTIONS'}, _, _, _, _) ->
+    {200, ?OPTIONS_HEADER, []};
+socket_handoff(_, #request{method = 'HEAD'}, _, _, _, _) ->
+    {200, ?HEADER, []};
+socket_handoff(_, _, _, _, _, _) ->
+    {400, ?HEADER, #xmlel{name = <<"h1">>,
+                          children = [{xmlcdata, <<"400 Bad Request">>}]}}.
+
+get_human_html_xmlel() ->
+    Heading = <<"ejabberd ", (jlib:atom_to_binary(?MODULE))/binary>>,
+    #xmlel{name = <<"html">>,
+           attrs =
+               [{<<"xmlns">>, <<"http://www.w3.org/1999/xhtml">>}],
+           children =
+               [#xmlel{name = <<"head">>, attrs = [],
+                       children =
+                           [#xmlel{name = <<"title">>, attrs = [],
+                                   children = [{xmlcdata, Heading}]}]},
+                #xmlel{name = <<"body">>, attrs = [],
+                       children =
+                           [#xmlel{name = <<"h1">>, attrs = [],
+                                   children = [{xmlcdata, Heading}]},
+                            #xmlel{name = <<"p">>, attrs = [],
+                                   children =
+                                       [{xmlcdata, <<"An implementation of ">>},
+                                        #xmlel{name = <<"a">>,
+                                               attrs =
+                                                   [{<<"href">>,
+                                                     <<"http://tools.ietf.org/html/rfc6455">>}],
+                                               children =
+                                                   [{xmlcdata,
+                                                     <<"WebSocket protocol">>}]}]},
+                            #xmlel{name = <<"p">>, attrs = [],
+                                   children =
+                                       [{xmlcdata,
+                                         <<"This web page is only informative. To "
+                                           "use WebSocket connection you need a Jabber/XMPP "
+                                           "client that supports it.">>}]}]}]}.
 
 connect(#ws{vsn = Vsn, socket = Socket, q = Q,
 	    origin = Origin, host = Host, port = Port,