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authorAnders Svensson <[email protected]>2011-05-18 18:29:12 +0200
committerAnders Svensson <[email protected]>2011-05-18 18:29:12 +0200
commit3c15ff32e89e401b4dde2b8acc9699be2614b996 (patch)
tree184dc988fb2ab3af04a532bc59cc794a8d74fbd3 /lib/diameter/src/app/diameter_config.erl
parentb1e768e86593178810c8a0b3c38443dcf6be5181 (diff)
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Initial commit of the diameter application.
The application provides an implementation of the Diameter protocol as defined in RFC 3588.
Diffstat (limited to 'lib/diameter/src/app/diameter_config.erl')
-rw-r--r--lib/diameter/src/app/diameter_config.erl681
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diff --git a/lib/diameter/src/app/diameter_config.erl b/lib/diameter/src/app/diameter_config.erl
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+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2010-2011. 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%
+%%
+
+%%
+%% This module writes service/transport configuration to the table
+%% diameter_config, so that the config will survive service process
+%% death, and then turns it into calls towards diameter_service. It
+%% also restarts services upon their death.
+%%
+%% The table diameter_config is only written here while
+%% diameter_service reads. This is all somewhat after the fact. Once
+%% upon a time the config was only stored in the service process,
+%% causing much grief if these processes died (which they did with
+%% some regularity) and one was forced to reconfigure. This module was
+%% then inserted into the service start in order to keep a more
+%% permanent record of the config. That said, service processes are
+%% now much more robust than they once were and crashing is a thing of
+%% the past.
+%%
+
+-module(diameter_config).
+-compile({no_auto_import, [monitor/2]}).
+
+-behaviour(gen_server).
+
+-export([start_service/2,
+ stop_service/1,
+ add_transport/2,
+ remove_transport/2,
+ have_transport/2,
+ lookup/1]).
+
+%% child server start
+-export([start_link/0]).
+
+%% gen_server callbacks
+-export([init/1,
+ terminate/2,
+ handle_call/3,
+ handle_cast/2,
+ handle_info/2,
+ code_change/3]).
+
+%% diameter_sync requests.
+-export([sync/1]).
+
+%% debug
+-export([state/0,
+ uptime/0]).
+
+-include_lib("diameter/include/diameter.hrl").
+-include("diameter_internal.hrl").
+
+%% Server state.
+-record(state, {id = now()}).
+
+%% Registered name of the server.
+-define(SERVER, ?MODULE).
+
+%% Table config is written to.
+-define(TABLE, ?MODULE).
+
+%% Workaround for dialyzer's lack of understanding of match specs.
+-type match(T)
+ :: T | '_' | '$1' | '$2' | '$3' | '$4'.
+
+%% Configuration records in ?TABLE.
+
+-record(service,
+ {name,
+ rec :: match(#diameter_service{}),
+ options :: match(list())}).
+
+-record(transport,
+ {service, %% name
+ ref = make_ref() :: match(reference()),
+ type :: match(connect | listen),
+ options :: match(list())}).
+
+%% Monitor entry in ?TABLE.
+-record(monitor, {mref = make_ref() :: reference(),
+ service}). %% name
+
+%% Time to lay low before restarting a dead service.
+-define(RESTART_SLEEP, 2000).
+
+%% A minimal diameter_caps for checking for valid capabilities values.
+-define(EXAMPLE_CAPS,
+ #diameter_caps{origin_host = "TheHost",
+ origin_realm = "TheRealm",
+ host_ip_address = [{127,0,0,1}],
+ vendor_id = 42,
+ product_name = "TheProduct"}).
+
+-define(VALUES(Rec), tl(tuple_to_list(Rec))).
+
+%%% The return values below assume the server diameter_config is started.
+%%% The functions will exit if it isn't.
+
+%% --------------------------------------------------------------------------
+%% # start_service(SvcName, Opts)
+%%
+%% Output: ok | {error, Reason}
+%% --------------------------------------------------------------------------
+
+start_service(SvcName, Opts)
+ when is_list(Opts) ->
+ start_rc(sync(SvcName, {start_service, SvcName, Opts})).
+
+start_rc({ok = T, _Pid}) ->
+ T;
+start_rc({error, _} = No) ->
+ No;
+start_rc(timeout) ->
+ {error, application_not_started}.
+
+%% --------------------------------------------------------------------------
+%% # stop_service(SvcName)
+%%
+%% Output: ok
+%% --------------------------------------------------------------------------
+
+stop_service(SvcName) ->
+ sync(SvcName, {stop_service, SvcName}).
+
+%% --------------------------------------------------------------------------
+%% # add_transport(SvcName, {Type, Opts})
+%%
+%% Input: Type = connect | listen
+%%
+%% Output: {ok, Ref} | {error, Reason}
+%% --------------------------------------------------------------------------
+
+add_transport(SvcName, {T, Opts})
+ when is_list(Opts), (T == connect orelse T == listen) ->
+ sync(SvcName, {add, SvcName, T, Opts}).
+
+%% --------------------------------------------------------------------------
+%% # remove_transport(SvcName, Pred)
+%%
+%% Input: Pred = arity 3 fun on transport ref, connect|listen and Opts,
+%% returning true if the transport is to be removed, false if
+%% not
+%% | arity 2 fun on Ref and Opts only
+%% | arity 1 fun on Opts only
+%% | Opts matching all transports that have all of the specified
+%% options
+%% | Ref matching only the transport with this reference.
+%% | {M,F,A} applied to Ref, connect|listen and Opts
+%% | boolean()
+%%
+%% Output: ok | {error, Reason}
+%% --------------------------------------------------------------------------
+
+remove_transport(SvcName, Pred) ->
+ try
+ sync(SvcName, {remove, SvcName, pred(Pred)})
+ catch
+ ?FAILURE(Reason) ->
+ {error, Reason}
+ end.
+
+pred(Pred)
+ when is_function(Pred, 3) ->
+ Pred;
+pred(Pred)
+ when is_function(Pred, 2) ->
+ fun(R,_,O) -> Pred(R,O) end;
+pred(Pred)
+ when is_function(Pred, 1) ->
+ fun(_,_,O) -> Pred(O) end;
+pred(Opts)
+ when is_list(Opts) ->
+ fun(_,_,O) -> [] == Opts -- O end;
+pred(Ref)
+ when is_reference(Ref) ->
+ fun(R,_,_) -> R == Ref end;
+pred({M,F,A})
+ when is_atom(M), is_atom(F), is_list(A) ->
+ fun(R,T,O) -> apply(M,F,[R,T,O|A]) end;
+pred({Type, Pred}) -> %% backwards compatibility
+ P = pred(Pred),
+ fun(R,T,O) -> T == Type andalso P(R,T,O) end;
+pred(B)
+ when is_boolean(B) ->
+ fun(_,_,_) -> B end;
+pred(_) ->
+ ?THROW(pred).
+
+%% --------------------------------------------------------------------------
+%% # have_transport/2
+%%
+%% Output: true | false
+%% --------------------------------------------------------------------------
+
+have_transport(SvcName, Ref) ->
+ member([{#transport{service = '$1',
+ ref = '$2',
+ _ = '_'},
+ [{'andalso', {'=:=', '$1', {const, SvcName}},
+ {'=:=', '$2', {const, Ref}}}],
+ [true]}]).
+
+%% --------------------------------------------------------------------------
+%% # lookup/1
+%% --------------------------------------------------------------------------
+
+lookup(SvcName) ->
+ select([{#service{name = '$1', rec = '$2', options = '$3'},
+ [{'=:=', '$1', {const, SvcName}}],
+ [{{'$1', '$2', '$3'}}]},
+ {#transport{service = '$1',
+ ref = '$2',
+ type = '$3',
+ options = '$4'},
+ [{'=:=', '$1', {const, SvcName}}],
+ [{{'$2', '$3', '$4'}}]}]).
+
+%% ---------------------------------------------------------
+%% EXPORTED INTERNAL FUNCTIONS
+%% ---------------------------------------------------------
+
+start_link() ->
+ ServerName = {local, ?SERVER},
+ Module = ?MODULE,
+ Args = [],
+ Options = [{spawn_opt, diameter_lib:spawn_opts(server, [])}],
+ gen_server:start_link(ServerName, Module, Args, Options).
+
+state() ->
+ call(state).
+
+uptime() ->
+ call(uptime).
+
+%%% ----------------------------------------------------------
+%%% # init/1
+%%% ----------------------------------------------------------
+
+init([]) ->
+ {ok, #state{}}.
+
+%%% ----------------------------------------------------------
+%%% # handle_call/2
+%%% ----------------------------------------------------------
+
+handle_call(state, _, State) ->
+ {reply, State, State};
+
+handle_call(uptime, _, #state{id = Time} = State) ->
+ {reply, diameter_lib:now_diff(Time), State};
+
+handle_call(Req, From, State) ->
+ warning_msg("received unexpected request from ~p:~n~w", [From, Req]),
+ Reply = {error, {bad_request, Req}},
+ {reply, Reply, State}.
+
+%%% ----------------------------------------------------------
+%%% # handle_cast/2
+%%% ----------------------------------------------------------
+
+handle_cast(Msg, State) ->
+ warning_msg("received unexpected message:~n~w", [Msg]),
+ {noreply, State}.
+
+%%% ----------------------------------------------------------
+%%% # handle_info/2
+%%% ----------------------------------------------------------
+
+%% A service process has died. This is most likely a consequence of
+%% stop_service, in which case the restart will find no config for the
+%% service and do nothing. The entry keyed on the monitor ref is only
+%% removed as a result of the 'DOWN' notification however.
+handle_info({'DOWN', MRef, process, _, Reason}, State) ->
+ [#monitor{service = SvcName} = T] = select([{#monitor{mref = MRef,
+ _ = '_'},
+ [],
+ ['$_']}]),
+ queue_restart(Reason, SvcName),
+ delete_object(T),
+ {noreply, State};
+
+handle_info({monitor, SvcName, Pid}, State) ->
+ monitor(Pid, SvcName),
+ {noreply, State};
+
+handle_info({restart, SvcName}, State) ->
+ restart(SvcName),
+ {noreply, State};
+
+handle_info(restart, State) ->
+ restart(),
+ {noreply, State};
+
+handle_info(Info, State) ->
+ warning_msg("received unknown info:~n~w", [Info]),
+ {noreply, State}.
+
+%%--------------------------------------------------------------------
+%% # terminate/2
+%%--------------------------------------------------------------------
+
+terminate(_Reason, _State) ->
+ ok.
+
+%%% ----------------------------------------------------------
+%%% # code_change/3
+%%% ----------------------------------------------------------
+
+code_change(_OldVsn, State, _Extra) ->
+ {ok, State}.
+
+%% ---------------------------------------------------------
+%% INTERNAL FUNCTIONS
+%% ---------------------------------------------------------
+
+insert(T) ->
+ ets:insert(?TABLE, T).
+
+%% ?TABLE is a bag: check only for a service entry.
+have_service(SvcName) ->
+ member([{#service{name = '$1', _ = '_'},
+ [{'=:=', '$1', {const, SvcName}}],
+ [true]}]).
+
+member(MatchSpec) ->
+ '$end_of_table' =/= ets:select(?TABLE, MatchSpec, 1).
+
+delete_object(T) ->
+ ets:delete_object(?TABLE, T).
+
+delete(Key) ->
+ ets:delete(?TABLE, Key).
+
+select(MatchSpec) ->
+ ets:select(?TABLE, MatchSpec).
+
+select_delete(MatchSpec) ->
+ ets:select_delete(?TABLE, MatchSpec).
+
+%% sync/2
+%%
+%% Interface functions used to be implemented as calls to ?SERVER but
+%% now serialize things per service instead since stopping a service
+%% can take time if the server doesn't answer DPR. A caller who wants
+%% to stop multiple services can then improve performance by spawning
+%% processes to stop them concurrently.
+
+sync(SvcName, T) ->
+ diameter_sync:call({?MODULE, SvcName},
+ {?MODULE, sync, [T]},
+ infinity,
+ infinity).
+
+%% sync/1
+
+sync({restart, SvcName}) ->
+ have_service(SvcName) andalso start(SvcName);
+
+sync({start_service, SvcName, Opts}) ->
+ try
+ start(have_service(SvcName), SvcName, Opts)
+ catch
+ ?FAILURE(Reason) -> {error, Reason}
+ end;
+
+sync({stop_service, SvcName}) ->
+ stop(SvcName);
+
+sync({add, SvcName, Type, Opts}) ->
+ try
+ add(SvcName, Type, Opts)
+ catch
+ ?FAILURE(Reason) -> {error, Reason}
+ end;
+
+sync({remove, SvcName, Pred}) ->
+ remove(select([{#transport{service = '$1', _ = '_'},
+ [{'=:=', '$1', {const, SvcName}}],
+ ['$_']}]),
+ SvcName,
+ Pred).
+
+%% start/3
+
+start(true, _, _) ->
+ {error, already_started};
+start(false, SvcName, Opts) ->
+ insert(make_config(SvcName, Opts)),
+ start(SvcName).
+
+%% start/1
+
+start(SvcName) ->
+ RC = diameter_service:start(SvcName),
+ startmon(SvcName, RC),
+ RC.
+
+startmon(SvcName, {ok, Pid}) ->
+ ?SERVER ! {monitor, SvcName, Pid};
+startmon(_, {error, _}) ->
+ ok.
+
+monitor(Pid, SvcName) ->
+ MRef = erlang:monitor(process, Pid),
+ insert(#monitor{mref = MRef, service = SvcName}).
+
+%% queue_restart/2
+
+%% Service has gone down on monitor death. Note that all service-related
+%% config is deleted.
+queue_restart({shutdown, {monitor, _}}, SvcName) ->
+ delete(SvcName);
+
+%% Application shutdown: ignore.
+queue_restart(shutdown, _) ->
+ ok;
+
+%% Or not.
+queue_restart(_, SvcName) ->
+ erlang:send_after(?RESTART_SLEEP, self(), {restart, SvcName}).
+
+%% restart/1
+
+restart(SvcName) ->
+ sync(SvcName, {restart, SvcName}).
+
+%% restart/0
+%%
+%% Start anything configured as required. Bang 'restart' to the server
+%% to kick things into gear manually. (Not that it should be required
+%% but it's been useful for test.)
+
+restart() ->
+ MatchSpec = [{#service{name = '$1', _ = '_'},
+ [],
+ ['$1']}],
+ lists:foreach(fun restart/1, select(MatchSpec)).
+
+%% stop/1
+
+stop(SvcName) ->
+ %% If the call to the service returns error for any reason other
+ %% than the process not being alive then deleting the config from
+ %% under it will surely bring it down.
+ diameter_service:stop(SvcName),
+ %% Delete only the service entry, not everything keyed on the name,
+ select_delete([{#service{name = '$1', _ = '_'},
+ [{'=:=', '$1', {const, SvcName}}],
+ [true]}]),
+ ok.
+%% Note that a transport has to be removed for its statistics to be
+%% deleted.
+
+%% add/3
+
+add(SvcName, Type, Opts) ->
+ %% Ensure usable capabilities. diameter_service:merge_service/2
+ %% depends on this.
+ lists:foreach(fun(Os) ->
+ is_list(Os) orelse ?THROW({capabilities, Os}),
+ ok = encode_CER(Os)
+ end,
+ [Os || {capabilities, Os} <- Opts, is_list(Os)]),
+
+ Ref = make_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
+ %% when the service is in that case.
+ case start_transport(SvcName, T) of
+ ok ->
+ insert(#transport{service = SvcName,
+ ref = Ref,
+ type = Type,
+ options = Opts}),
+ {ok, Ref};
+ {error, _} = No ->
+ No
+ end.
+
+start_transport(SvcName, T) ->
+ case diameter_service:start_transport(SvcName, T) of
+ {ok, _Pid} ->
+ ok;
+ {error, no_service} ->
+ ok;
+ {error, _} = No ->
+ 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)).
+
+rm(_, []) ->
+ ok;
+rm(SvcName, L) ->
+ Refs = lists:map(fun(#transport{ref = R}) -> R end, L),
+ case stop_transport(SvcName, Refs) of
+ ok ->
+ lists:foreach(fun delete_object/1, L);
+ {error, _} = No ->
+ No
+ end.
+
+stop_transport(SvcName, Refs) ->
+ case diameter_service:stop_transport(SvcName, Refs) of
+ ok ->
+ ok;
+ {error, no_service} ->
+ ok;
+ {error, _} = No ->
+ No
+ end.
+
+%% make_config/2
+
+make_config(SvcName, Opts) ->
+ Apps = init_apps(Opts),
+ [] == Apps andalso ?THROW(no_apps),
+
+ %% Use the fact that diameter_caps has the same field names as CER.
+ Fields = diameter_gen_base_rfc3588:'#info-'(diameter_base_CER) -- ['AVP'],
+
+ COpts = [T || {K,_} = T <- Opts, lists:member(K, Fields)],
+ Caps = make_caps(#diameter_caps{}, COpts),
+
+ ok = encode_CER(COpts),
+
+ Os = split(Opts, [{[fun erlang:is_boolean/1], false, share_peers},
+ {[fun erlang:is_boolean/1], false, use_shared_peers},
+ {[fun erlang:is_pid/1, false], false, monitor}]),
+ %% share_peers and use_shared_peers are currently undocumented.
+
+ #service{name = SvcName,
+ rec = #diameter_service{applications = Apps,
+ capabilities = Caps},
+ options = Os}.
+
+make_caps(Caps, Opts) ->
+ case diameter_capx:make_caps(Caps, Opts) of
+ {ok, T} ->
+ T;
+ {error, {Reason, _}} ->
+ ?THROW(Reason)
+ end.
+
+%% Validate types by encoding a CER.
+encode_CER(Opts) ->
+ {ok, CER} = diameter_capx:build_CER(make_caps(?EXAMPLE_CAPS, Opts)),
+
+ Hdr = #diameter_header{version = ?DIAMETER_VERSION,
+ end_to_end_id = 0,
+ hop_by_hop_id = 0},
+
+ try
+ diameter_codec:encode(?BASE, #diameter_packet{header = Hdr,
+ msg = CER}),
+ ok
+ catch
+ exit: Reason ->
+ ?THROW(Reason)
+ end.
+
+init_apps(Opts) ->
+ lists:foldl(fun app_acc/2, [], lists:reverse(Opts)).
+
+app_acc({application, Opts}, Acc) ->
+ is_list(Opts) orelse ?THROW({application, Opts}),
+
+ [Dict, Mod] = get_opt([dictionary, module], Opts),
+ Alias = get_opt(alias, Opts, Dict),
+ ModS = get_opt(state, Opts, Alias),
+ M = get_opt(call_mutates_state, Opts, false),
+ A = get_opt(answer_errors, Opts, report),
+ [#diameter_app{alias = Alias,
+ dictionary = Dict,
+ id = cb(Dict, id),
+ module = init_mod(Mod),
+ init_state = ModS,
+ mutable = init_mutable(M),
+ answer_errors = init_answers(A)}
+ | Acc];
+app_acc(_, Acc) ->
+ Acc.
+
+init_mod(M)
+ when is_atom(M) ->
+ [M];
+init_mod([M|_] = L)
+ when is_atom(M) ->
+ L;
+init_mod(M) ->
+ ?THROW({module, M}).
+
+init_mutable(M)
+ when M == true;
+ M == false ->
+ M;
+init_mutable(M) ->
+ ?THROW({call_mutates_state, M}).
+
+init_answers(A)
+ when callback == A;
+ report == A;
+ discard == A ->
+ A;
+init_answers(A) ->
+ ?THROW({answer_errors, A}).
+
+%% Get a single value at the specified key.
+get_opt(Keys, List)
+ when is_list(Keys) ->
+ [get_opt(K, List) || K <- Keys];
+get_opt(Key, List) ->
+ case [V || {K,V} <- List, K == Key] of
+ [V] -> V;
+ _ -> ?THROW({arity, Key})
+ end.
+
+%% Get an optional value at the specified key.
+get_opt(Key, List, Def) ->
+ case [V || {K,V} <- List, K == Key] of
+ [] -> Def;
+ [V] -> V;
+ _ -> ?THROW({arity, Key})
+ end.
+
+split(Opts, Defs) ->
+ [{K, value(D, Opts)} || {_,_,K} = D <- Defs].
+
+value({Preds, Def, Key}, Opts) ->
+ V = get_opt(Key, Opts, Def),
+ lists:any(fun(P) -> pred(P,V) end, Preds)
+ orelse ?THROW({value, Key}),
+ V.
+
+pred(F, V)
+ when is_function(F) ->
+ F(V);
+pred(T, V) ->
+ T == V.
+
+cb(M,F) ->
+ try M:F() of
+ V -> V
+ catch
+ E: Reason ->
+ ?THROW({callback, E, Reason, ?STACK})
+ end.
+
+%% call/1
+
+call(Request) ->
+ gen_server:call(?SERVER, Request, infinity).
+
+%% warning_msg/2
+
+warning_msg(F, A) ->
+ ?diameter_warning("~p: " ++ F, [?MODULE | A]).