From 5ca5fb71695ccdf7267007b8405f7a13497a2f17 Mon Sep 17 00:00:00 2001 From: Anders Svensson Date: Wed, 18 May 2016 14:39:32 +0200 Subject: Close listening sockets at transport removal The transport interface documented in diameter_transport(3) is used to start/stop accepting/connecting transport processes: they're started with a function call, and told to die with their parent process. In the accepting case, both diameter_tcp and diameter_sctp start a listening process when the first accepting transport is started. However, there's no way for a listening process to find out that that it should stop listening when transport configuration is removed. Both diameter_tcp and diameter_sctp have used a timer to terminate the listening process after all existing accepting processes have died as a consequence of transport removal. The problem with this is that nothing stops a new client from connecting before this, and also that no new transport can succeed in opening the same listening port (eg. reconfiguration) until the old listener dies. This commit solves the problem by adding diameter_reg:subscribe/2, to allow callers to subscribe to messages about added/removed associations. A call to diameter:add_transport/2 results in a new child process that registers a term that a listening process subscribes to. Transport removal results in the death of the child, and the resulting notification to the listener causes the latter to close its socket and terminate. This is still an internal interface, but the subscription mechanism should probably be made external (eg. a diameter:subscribe/1 that can be used to subscribe to specified messages), so that transport modules other than diameter's own can make use of it. There is no support for soft upgrade. --- lib/diameter/src/base/diameter_config.erl | 106 ++++++++++++++++++++------ lib/diameter/src/base/diameter_config_sup.erl | 58 ++++++++++++++ lib/diameter/src/base/diameter_sup.erl | 3 +- 3 files changed, 142 insertions(+), 25 deletions(-) create mode 100644 lib/diameter/src/base/diameter_config_sup.erl (limited to 'lib/diameter/src/base') diff --git a/lib/diameter/src/base/diameter_config.erl b/lib/diameter/src/base/diameter_config.erl index 702f11593a..73b828536b 100644 --- a/lib/diameter/src/base/diameter_config.erl +++ b/lib/diameter/src/base/diameter_config.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2010-2015. All Rights Reserved. +%% Copyright Ericsson AB 2010-2016. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -45,10 +45,12 @@ add_transport/2, remove_transport/2, have_transport/2, - lookup/1]). + lookup/1, + subscribe/2]). -%% child server start --export([start_link/0]). +%% server start +-export([start_link/0, + start_link/1]). %% gen_server callbacks -export([init/1, @@ -58,8 +60,9 @@ handle_info/2, code_change/3]). -%% diameter_sync requests. --export([sync/1]). +%% callbacks +-export([sync/1, %% diameter_sync requests + remove/0]). %% transport server termination %% debug -export([state/0, @@ -77,6 +80,9 @@ %% Table config is written to. -define(TABLE, ?MODULE). +%% Key on which a transport-specific child registers itself. +-define(TRANSPORT_KEY(Ref), {?MODULE, transport, Ref}). + %% Workaround for dialyzer's lack of understanding of match specs. -type match(T) :: T | '_' | '$1' | '$2' | '$3' | '$4'. @@ -224,6 +230,13 @@ pred(B) pred(_) -> ?THROW(pred). +%% -------------------------------------------------------------------------- +%% # subscribe/2 +%% -------------------------------------------------------------------------- + +subscribe(Ref, T) -> + diameter_reg:subscribe(?TRANSPORT_KEY(Ref), T). + %% -------------------------------------------------------------------------- %% # have_transport/2 %% @@ -264,6 +277,9 @@ start_link() -> Options = [{spawn_opt, diameter_lib:spawn_opts(server, [])}], gen_server:start_link(ServerName, Module, Args, Options). +start_link(T) -> + proc_lib:start_link(?MODULE, init, [T], infinity, []). + state() -> call(state). @@ -274,8 +290,42 @@ uptime() -> %%% # init/1 %%% ---------------------------------------------------------- +%% ?SERVER start. init([]) -> - {ok, #state{}}. + {ok, #state{}}; + +%% Child start as a consequence of add_transport. +init({SvcName, Type, Opts}) -> + Res = try + add(SvcName, Type, Opts) + catch + ?FAILURE(Reason) -> {error, Reason} + end, + proc_lib:init_ack({ok, self(), Res}), + sleep(Res). + +%% sleep/1 + +sleep({ok, _}) -> + sleep(); + +sleep({error, _}) -> + ok. %% die + +%% sleep/0 + +sleep() -> + proc_lib:hibernate(?MODULE, remove, []). + +%% remove/0 + +remove() -> + receive + {?MODULE, stop} -> + ok; + _ -> + sleep() + end. %%% ---------------------------------------------------------- %%% # handle_call/2 @@ -404,19 +454,22 @@ sync({start_service, SvcName, Opts}) -> sync({stop_service, SvcName}) -> stop(SvcName); +%% Start a child whose only purpose is to be alive for the lifetime of +%% the transport configuration and publish itself in diameter_reg. +%% This is to provide a way for processes to to be notified when the +%% configuration is removed (diameter_reg:subscribe/2). sync({add, SvcName, Type, Opts}) -> - try - add(SvcName, Type, Opts) - catch - ?FAILURE(Reason) -> {error, Reason} - end; + {ok, _Pid, Res} = diameter_config_sup:start_child({SvcName, Type, Opts}), + Res; sync({remove, SvcName, Pred}) -> - remove(select([{#transport{service = '$1', _ = '_'}, + Recs = select([{#transport{service = '$1', _ = '_'}, [{'=:=', '$1', {const, SvcName}}], ['$_']}]), - SvcName, - Pred). + F = fun(#transport{ref = R, type = T, options = O}) -> + Pred(R,T,O) + end, + remove(SvcName, lists:filter(F, Recs)). %% start/3 @@ -503,6 +556,7 @@ add(SvcName, Type, Opts) -> ok = transport_opts(Opts), Ref = make_ref(), + true = diameter_reg:add_new(?TRANSPORT_KEY(Ref)), T = {Ref, Type, Opts}, %% The call to the service returns error if the service isn't %% started yet, which is harmless. The transport will be started @@ -594,26 +648,30 @@ start_transport(SvcName, T) -> No end. -%% remove/3 - -remove(L, SvcName, Pred) -> - rm(SvcName, lists:filter(fun(#transport{ref = R, type = T, options = O}) -> - Pred(R,T,O) - end, - L)). +%% remove/2 -rm(_, []) -> +remove(_, []) -> ok; -rm(SvcName, L) -> + +remove(SvcName, L) -> Refs = lists:map(fun(#transport{ref = R}) -> R end, L), case stop_transport(SvcName, Refs) of ok -> + lists:foreach(fun stop_child/1, Refs), diameter_stats:flush(Refs), lists:foreach(fun delete_object/1, L); {error, _} = No -> No end. +stop_child(Ref) -> + case diameter_reg:match(?TRANSPORT_KEY(Ref)) of + [{_, Pid}] -> %% tell the transport-specific child to die + Pid ! {?MODULE, stop}; + [] -> %% already removed/dead + ok + end. + stop_transport(SvcName, Refs) -> case diameter_service:stop_transport(SvcName, Refs) of ok -> diff --git a/lib/diameter/src/base/diameter_config_sup.erl b/lib/diameter/src/base/diameter_config_sup.erl new file mode 100644 index 0000000000..9524573378 --- /dev/null +++ b/lib/diameter/src/base/diameter_config_sup.erl @@ -0,0 +1,58 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2016. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% + +%% +%% Supervisor for config processes. +%% + +-module(diameter_config_sup). + +-behaviour(supervisor). + +%% interface +-export([start_link/0, %% supervisor start + start_child/1]). %% config start + +-export([init/1]). + +-define(NAME, ?MODULE). %% supervisor name + +%% start_link/0 + +start_link() -> + SupName = {local, ?NAME}, + supervisor:start_link(SupName, ?MODULE, []). + +%% start_child/1 + +start_child(T) -> + supervisor:start_child(?NAME, [T]). + +%% init/1 + +init([]) -> + Mod = diameter_config, + Flags = {simple_one_for_one, 0, 1}, + ChildSpec = {Mod, + {Mod, start_link, []}, + temporary, + 1000, + worker, + [Mod]}, + {ok, {Flags, [ChildSpec]}}. diff --git a/lib/diameter/src/base/diameter_sup.erl b/lib/diameter/src/base/diameter_sup.erl index e89ede9843..482289cb9a 100644 --- a/lib/diameter/src/base/diameter_sup.erl +++ b/lib/diameter/src/base/diameter_sup.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2010-2015. All Rights Reserved. +%% Copyright Ericsson AB 2010-2016. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. @@ -34,6 +34,7 @@ -export([init/1]). -define(CHILDREN, [diameter_misc_sup, + diameter_config_sup, diameter_watchdog_sup, diameter_peer_fsm_sup, diameter_transport_sup, -- cgit v1.2.3