%%%---------------------------------------------------------------------- %%% File : ejabberd_global_router.erl %%% Author : Geoff Cant %%% Purpose : Router for virtual global routes %%% Created : 07 Aug 2002 by Geoff Cant %%% %%% %%% ejabberd, Copyright (C) 2002-2009 ProcessOne %%% %%% This program is free software; you can redistribute it and/or %%% modify it under the terms of the GNU General Public License as %%% published by the Free Software Foundation; either version 2 of the %%% License, or (at your option) any later version. %%% %%% This program is distributed in the hope that it will be useful, %%% but WITHOUT ANY WARRANTY; without even the implied warranty of %%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU %%% General Public License for more details. %%% %%% You should have received a copy of the GNU General Public License %%% along with this program; if not, write to the Free Software %%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA %%% 02111-1307 USA %%% %%%---------------------------------------------------------------------- -module(ejabberd_global_router). -behaviour(gen_server). -include("ejabberd.hrl"). -include("ejabberd_global_router.hrl"). %% API -export([start_link/0 ,route/3 ,route/4 ,find_route/1 ,register_route/1 ,register_route/2 ,unregister_route/1 ,unregister_route/2 ,expand_routes/1 ,all_prefixes/0 ,server_host/2 ]). %% Eunit test exports. -export([remove_prefix/2 ,find_prefix/2 ]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -record(state, {}). %%==================================================================== %% API %%==================================================================== %%-------------------------------------------------------------------- %% @spec start_link() -> {ok,Pid} | ignore | {error,Error} %% @doc Starts the server %% @end %%-------------------------------------------------------------------- start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). route(From, To, Packet) -> case find_route(To) of Route = #global_route{} -> route(Route, From, To, Packet); no_route -> ok end. route(#global_route{pids=Pids}, From, To, Packet) -> Pid = pick_route(Pids), Pid ! {route, From, To, Packet}, ok. find_route(Domain) -> case prefix_match(Domain, all_prefixes()) of nomatch -> no_route; Prefix when is_list(Prefix) -> dirty_get_route(Prefix) end. register_route(Prefix) -> register_route(Prefix, self()). register_route(Prefix, Pid) -> Route = #global_route{prefix=Prefix, pids=[Pid]}, {atomic, ok} = mnesia:transaction(fun write_route/1, [Route]), ok. unregister_route(Prefix) -> unregister_route(Prefix, self()). unregister_route(Prefix, Pid) -> mnesia:transaction(fun delete_route/2, [Prefix, Pid]). expand_routes(Domain) -> [expand_route(Prefix, Domain) || Prefix <- all_prefixes()]. expand_route(Prefix, Domain) -> lists:append([Prefix, ".", Domain]). all_prefixes() -> mnesia:dirty_all_keys(global_route). server_host(Host, Pid) -> #global_route{prefix=P,pids=Pids} = find_route(Host), true = lists:member(Pid, Pids), remove_prefix(P, Host). %%==================================================================== %% gen_server callbacks %%==================================================================== %%-------------------------------------------------------------------- %% @private %% @spec init(Args) -> {ok, State} | %% {ok, State, Timeout} | %% ignore | %% {stop, Reason} %% @doc Initialises the server's state %% @end %%-------------------------------------------------------------------- init([]) -> update_tables(), mnesia:create_table(global_route, [{ram_copies, [node()]}, {type, set}, {attributes, record_info(fields, global_route)}]), mnesia:add_table_copy(global_route, node(), ram_copies), {ok, #state{}}. %%-------------------------------------------------------------------- %% @private %% @spec %% handle_call(Request, From, State) -> {reply, Reply, State} | %% {reply, Reply, State, Timeout} | %% {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, Reply, State} | %% {stop, Reason, State} %% @doc Call message handler callbacks %% @end %%-------------------------------------------------------------------- handle_call(Call, _From, State) -> ?WARNING_MSG("Unexpected call ~p.", [Call]), {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @spec %% handle_cast(Msg, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% @doc Cast message handler callbacks %% @end %%-------------------------------------------------------------------- handle_cast(Msg, State) -> ?WARNING_MSG("Unexpected cast ~p", [Msg]), {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @spec %% handle_info(Info, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% @doc Non gen-server message handler callbacks %% @end %%-------------------------------------------------------------------- handle_info(Info, State) -> ?WARNING_MSG("Unexpected info ~p", [Info]), {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @spec terminate(Reason, State) -> void() %% @doc This function is called by a gen_server when it is about to %% terminate. It should be the opposite of Module:init/1 and do any necessary %% cleaning up. When it returns, the gen_server terminates with Reason. %% The return value is ignored. %% @end %%-------------------------------------------------------------------- terminate(_Reason, _State) -> ok. %%-------------------------------------------------------------------- %% @private %% @spec code_change(OldVsn, State, Extra) -> {ok, NewState} %% @doc Convert process state when code is changed %% @end %%-------------------------------------------------------------------- code_change(_OldVsn, State, _Extra) -> {ok, State}. pick_route(Pids) when is_list(Pids) -> pick_local_route(Pids). pick_local_route(Pids) when is_list(Pids) -> case [Pid || Pid <- Pids, node(Pid) =:= node()] of [] -> pick_remote_route(Pids); LocalPids -> pick_one_route(LocalPids) end. pick_remote_route(Pids) when is_list(Pids) -> pick_one_route(Pids). pick_one_route(Pids) when is_list(Pids) -> hd(Pids). % should pick random pid? update_tables() -> CorrectAttributes = record_info(fields, global_route), case catch mnesia:table_info(global_route, attributes) of CorrectAttributes -> ok; IncorrectAttributes when is_list(IncorrectAttributes) -> mnesia:delete_table(global_route); {'EXIT', _} -> ok end. write_route(R = #global_route{prefix=Prefix}) -> NewRoute = case mnesia:read({global_route, Prefix}) of [] -> R; [OldRoute] -> combine_routes(OldRoute, R) end, ok = mnesia:write(NewRoute). delete_route(Prefix, Pid) -> case mnesia:read({global_route, Prefix}, write) of [] -> ok; [#global_route{pids=[Pid]}] -> mnesia:delete({global_route, Prefix}); [Route = #global_route{pids=Pids}] -> mnesia:write(Route#global_route{pids=Pids -- [Pid]}) end. combine_routes(R = #global_route{prefix=P, pids=APids}, #global_route{prefix=P, pids=BPids}) -> R#global_route{pids=lists:usort(APids ++ BPids)}. prefix_match(Domain, Prefixes) -> case find_prefix(Domain, Prefixes) of [] -> nomatch; [Prefix] -> Prefix; _Prefixes -> erlang:error(multiple_prefix_matches) end. dirty_get_route(Prefix) -> case mnesia:dirty_read({global_route, Prefix}) of [Route = #global_route{}] -> Route; _ -> no_route end. find_prefix(Domain, PossiblePrefixes) -> [Prefix || Prefix <- PossiblePrefixes, lists:prefix(Prefix, Domain)]. remove_prefix(Prefix, Domain) -> [$. | BareDomain] = Domain -- Prefix, BareDomain. %%-------------------------------------------------------------------- %%% Eunit Tests. %%--------------------------------------------------------------------