* src/web/*: Plugin architecture for HTTP modules (thanks to

Massimiliano Mirra)

SVN Revision: 713

ChangeLog

@@ -1,3 +1,8 @@
+2007-01-25  Alexey Shchepin  <alexey@sevcom.net>
+
+	* src/web/*: Plugin architecture for HTTP modules (thanks to
+	Massimiliano Mirra)
+
 2007-01-24  Mickael Remond  <mickael.remond@process-one.net>
 
 	* doc/guide.tex: Documentation for the

src/web/ejabberd_http.erl

@@ -31,8 +31,15 @@
 		request_keepalive,
 		request_content_length,
 		request_lang = "en",
-		use_http_poll = false,
+		%% XXX bard: request handlers are configured in
-		use_web_admin = false,
+		%% ejabberd.cfg under the HTTP service.	 For example,
+		%% to have the module test_web handle requests with
+		%% paths starting with "/test/module":
+		%%
+		%%   {5280, ejabberd_http,    [http_poll, web_admin,
+		%%			       {request_handlers, [{["test", "module"], mod_test_web}]}]}
+		%%
+		request_handlers = [],
 		end_of_request = false,
 		trail = ""
 	       }).
@@ -71,16 +78,32 @@ start_link({SockMod, Socket}, Opts) ->
 	_ ->
 	    ok
     end,
-    UseHTTPPoll = lists:member(http_poll, Opts),
+
-    UseWebAdmin = lists:member(web_admin, Opts),
+    %% XXX bard: for backward compatibility: expand web_admin and
-    ?DEBUG("S: ~p~n", [{UseHTTPPoll, UseWebAdmin}]),
+    %% http_poll in Opts respectively to {["admin"],
+    %% ejabberd_web_admin} and {["http-poll"], ejabberd_http_poll}
+        
+    RequestHandlers =
+	case lists:keysearch(request_handlers, 1, Opts) of
+             {value, {request_handlers, H}} -> H;
+             false -> []
+        end ++
+        case lists:member(web_admin, Opts) of
+            true -> [{["admin"], ejabberd_web_admin}];
+            false -> []
+        end ++
+        case lists:member(http_poll, Opts) of
+            true -> [{["http-poll"], ejabberd_http_poll}];
+            false -> []
+        end,
+    ?DEBUG("S: ~p~n", [RequestHandlers]),
+
     ?INFO_MSG("started: ~p", [{SockMod1, Socket1}]),
     {ok, proc_lib:spawn_link(ejabberd_http,
 			     receive_headers,
 			     [#state{sockmod = SockMod1,
 				     socket = Socket1,
-				     use_http_poll = UseHTTPPoll,
+				     request_handlers = RequestHandlers}])}.
-				     use_web_admin = UseWebAdmin}])}.
 
 
 become_controller(_Pid) ->
@@ -192,23 +215,44 @@ process_header(State, Data) ->
 		    end,
 		    #state{sockmod = SockMod,
 			   socket = Socket,
-			   use_http_poll = State#state.use_http_poll,
+			   request_handlers = State#state.request_handlers};
-			   use_web_admin = State#state.use_web_admin};
 		_ ->
-		    #state{end_of_request = true}
+		    #state{end_of_request = true,
+			   request_handlers = State#state.request_handlers}
 	    end;
 	{error, _Reason} ->
-	    #state{end_of_request = true};
+	    #state{end_of_request = true,
+		   request_handlers = State#state.request_handlers};
 	_ ->
-	    #state{end_of_request = true}
+	    #state{end_of_request = true,
+		   request_handlers = State#state.request_handlers}
+    end.
+
+%% XXX bard: search through request handlers looking for one that
+%% 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, Request) ->
+    [{PathPattern, HandlerModule} | HandlersLeft] = Handlers,
+    
+    case lists:prefix(PathPattern, Request#request.path) of
+	true ->
+            %% 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(PathPattern), Request#request.path),
+	    HandlerModule:process(LocalPath, Request);
+	false ->
+	    process(HandlersLeft, Request)
     end.
 
 process_request(#state{request_method = 'GET',
 		       request_path = {abs_path, Path},
 		       request_auth = Auth,
 		       request_lang = Lang,
-		       use_http_poll = UseHTTPPoll,
+		       request_handlers = RequestHandlers} = State) ->
-		       use_web_admin = UseWebAdmin} = State) ->
     case (catch url_decode_q_split(Path)) of
 	{'EXIT', _} ->
 	    process_request(false);
@@ -225,8 +269,11 @@ process_request(#state{request_method = 'GET',
 			       q = LQuery,
 			       auth = Auth,
 			       lang = Lang},
-	    case ejabberd_web:process_get({UseHTTPPoll, UseWebAdmin},
+	    %% XXX bard: This previously passed control to
-					  Request) of
+	    %% ejabberd_web:process_get, now passes it to a local
+	    %% procedure (process) that handles dispatching based on
+	    %% URL path prefix.
+	    case process(RequestHandlers, Request) of
 		El when element(1, El) == xmlelement ->
 		    make_xhtml_output(State, 200, [], El);
 		{Status, Headers, El} when
@@ -247,8 +294,7 @@ process_request(#state{request_method = 'POST',
 		       request_lang = Lang,
 		       sockmod = SockMod,
 		       socket = Socket,
-		       use_http_poll = UseHTTPPoll,
+		       request_handlers = RequestHandlers} = State)
-		       use_web_admin = UseWebAdmin} = State)
   when is_integer(Len) ->
     case SockMod of
 	gen_tcp ->
@@ -275,8 +321,7 @@ process_request(#state{request_method = 'POST',
 			       auth = Auth,
 			       data = Data,
 			       lang = Lang},
-	    case ejabberd_web:process_get({UseHTTPPoll, UseWebAdmin},
+	    case process(RequestHandlers, Request) of
-					  Request) of
 		El when element(1, El) == xmlelement ->
 		    make_xhtml_output(State, 200, [], El);
 		{Status, Headers, El} when

src/web/ejabberd_http_poll.erl

@@ -24,7 +24,7 @@
 	 setopts/2,
 	 controlling_process/2,
 	 close/1,
-	 process_request/1]).
+	 process/2]).
 
 -include("ejabberd.hrl").
 -include("jlib.hrl").
@@ -83,8 +83,7 @@ close({http_poll, FsmRef}) ->
     catch gen_fsm:sync_send_all_state_event(FsmRef, close).
 
 
-process_request(#request{path = [],
+process([], #request{data = Data} = Request) ->
-			 data = Data} = Request) ->
     case catch parse_request(Data) of
 	{ok, ID1, Key, NewKey, Packet} ->
 	    ID = if
@@ -130,7 +129,7 @@ process_request(#request{path = [],
 	_ ->
 	    {200, [?CT, {"Set-Cookie", "ID=-2:0; expires=-1"}], ""}
     end;
-process_request(_Request) ->
+process(_, _Request) ->
     {400, [], {xmlelement, "h1", [],
 	       [{xmlcdata, "400 Bad Request"}]}}.
 

src/web/ejabberd_web.erl

@@ -12,13 +12,18 @@
 
 %% External exports
 -export([make_xhtml/1,
-	 process_get/2]).
+         error/1]).
 
 -include("ejabberd.hrl").
 -include("jlib.hrl").
 -include("ejabberd_http.hrl").
 
 
+%% XXX bard: there are variants of make_xhtml in ejabberd_http and
+%% ejabberd_web_admin.  It might be a good idea to centralize it here
+%% and also create an ejabberd_web.hrl file holding the macros, so
+%% that third parties can use ejabberd_web as an "utility" library.
+
 make_xhtml(Els) ->
     {xmlelement, "html", [{"xmlns", "http://www.w3.org/1999/xhtml"},
 			  {"xml:lang", "en"},
@@ -48,98 +53,7 @@ make_xhtml(Els) ->
 		      {"name", Name},
 		      {"value", Value}])).
 
-
+error(not_found) ->
-process_get({_, true},
+    {404, [], make_xhtml([?XC("h1", "404 Not Found")])};
-	    #request{auth = Auth,
+error(not_allowed) ->
-		     path = ["admin", "server", SHost | RPath],
+    {401, [], make_xhtml([?XC("h1", "401 Unauthorized")])}.
-		     q = Query,
-		     lang = Lang} = Request) ->
-    Host = jlib:nameprep(SHost),
-    case lists:member(Host, ?MYHOSTS) of
-	true ->
-	    US = case Auth of
-		     {SJID, P} ->
-			 case jlib:string_to_jid(SJID) of
-			     error ->
-				 unauthorized;
-			     #jid{user = U, server = S} ->
-				 case ejabberd_auth:check_password(U, S, P) of
-				     true ->
-					 {U, S};
-				     false ->
-					 unauthorized
-				 end
-			 end;
-		     _ ->
-			 unauthorized
-		 end,
-	    case US of
-		{User, Server} ->
-		    case acl:match_rule(
-			   Host, configure, jlib:make_jid(User, Server, "")) of
-			deny ->
-			    {401, [], make_xhtml([?XC("h1", "Not Allowed")])};
-			allow ->
-			    ejabberd_web_admin:process_admin(
-			      Host, Request#request{path = RPath,
-						    us = US})
-		    end;
-		unauthorized ->
-		    {401,
-		     [{"WWW-Authenticate", "basic realm=\"ejabberd\""}],
-		     ejabberd_web:make_xhtml([{xmlelement, "h1", [],
-					       [{xmlcdata, "401 Unauthorized"}]}])}
-	    end;
-	false ->
-	    {404, [], make_xhtml([?XC("h1", "Not found")])}
-    end;
-
-process_get({_, true},
-	    #request{auth = Auth,
-		     path = ["admin" | RPath],
-		     q = Query,
-		     lang = Lang} = Request) ->
-    US = case Auth of
-	     {SJID, P} ->
-		 case jlib:string_to_jid(SJID) of
-		     error ->
-			 unauthorized;
-		     #jid{user = U, server = S} ->
-			 case ejabberd_auth:check_password(U, S, P) of
-			     true ->
-				 {U, S};
-			     false ->
-				 unauthorized
-			 end
-		 end;
-	     _ ->
-		 unauthorized
-	 end,
-    case US of
-	{User, Server} ->
-	    case acl:match_rule(
-		   global, configure, jlib:make_jid(User, Server, "")) of
-		deny ->
-		    {401, [], make_xhtml([?XC("h1", "Not Allowed")])};
-		allow ->
-		    ejabberd_web_admin:process_admin(
-		      global, Request#request{path = RPath,
-					      us = US})
-	    end;
-	unauthorized ->
-	    {401,
-	     [{"WWW-Authenticate", "basic realm=\"ejabberd\""}],
-	     ejabberd_web:make_xhtml([{xmlelement, "h1", [],
-				       [{xmlcdata, "401 Unauthorized"}]}])}
-    end;
-
-process_get({true, _},
-	    #request{path = ["http-poll" | RPath],
-		     q = _Query,
-		     lang = _Lang} = Request) ->
-    ejabberd_http_poll:process_request(Request#request{path = RPath});
-
-process_get(_, _Request) ->
-    {404, [], make_xhtml([?XC("h1", "Not found")])}.
-
-

src/web/ejabberd_web_admin.erl

@@ -14,7 +14,9 @@
 -vsn('$Revision$ ').
 
 %% External exports
--export([process_admin/2,
+-export([process/2,
+         %% XXX bard: unexported, since it is only called from process/2 now
+         %% process_admin/2,
 	 list_users/4,
 	 list_users_in_diapason/4]).
 
@@ -54,6 +56,75 @@
 		      {"size", Size}])).
 -define(INPUTST(Type, Name, Value, Size), ?INPUT(Type, Name, ?T(Value), Size)).
 
+
+process(["server", SHost | RPath], #request{auth = Auth,
+                                            q = Query,
+                                            lang = Lang} = Request) ->
+    Host = jlib:nameprep(SHost),
+    case lists:member(Host, ?MYHOSTS) of
+	true ->
+	    case get_auth(Auth) of
+		{User, Server} ->
+		    case acl:match_rule(
+			   Host, configure, jlib:make_jid(User, Server, "")) of
+			deny ->
+                            ejabberd_web:error(not_allowed);
+			allow ->
+			    process_admin(
+			      Host, Request#request{path = RPath,
+						    us = {User, Server}})
+		    end;
+		unauthorized ->
+		    {401,
+		     [{"WWW-Authenticate", "basic realm=\"ejabberd\""}],
+		     ejabberd_web:make_xhtml([{xmlelement, "h1", [],
+                                               [{xmlcdata, "401 Unauthorized"}]}])}
+	    end;
+	false ->
+            ejabberd_web:error(not_found)
+    end;
+
+process(RPath, #request{auth = Auth,
+                        q = Query,
+                        lang = Lang} = Request) ->
+    case get_auth(Auth) of
+	{User, Server} ->
+	    case acl:match_rule(
+		   global, configure, jlib:make_jid(User, Server, "")) of
+		deny ->
+                    ejabberd_web:error(not_allowed);
+		allow ->
+		    process_admin(
+		      global, Request#request{path = RPath,
+					      us = {User, Server}})
+	    end;
+	unauthorized ->
+            %% XXX bard: any reason to send this data now and not
+            %% always in case of an 401? ought to check http specs...
+	    {401, 
+	     [{"WWW-Authenticate", "basic realm=\"ejabberd\""}],
+	     ejabberd_web:make_xhtml([{xmlelement, "h1", [],
+				       [{xmlcdata, "401 Unauthorized"}]}])}
+    end.
+
+get_auth(Auth) ->
+    case Auth of
+        {SJID, P} ->
+            case jlib:string_to_jid(SJID) of
+                error ->
+                    unauthorized;
+                #jid{user = U, server = S} ->
+                    case ejabberd_auth:check_password(U, S, P) of
+                        true ->
+                            {U, S};
+                        false ->
+                            unauthorized
+                    end
+            end;
+         _ ->
+            unauthorized
+    end.
+
 make_xhtml(Els, global, Lang) ->
     {200, [html],
      {xmlelement, "html", [{"xmlns", "http://www.w3.org/1999/xhtml"},