%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2010-2013. 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% %% %% %% Implements the process that represents a service. %% -module(diameter_service). -behaviour(gen_server). -export([start/1, stop/1, start_transport/2, stop_transport/2, info/2, call/4]). %% towards diameter_watchdog -export([receive_message/3]). %% service supervisor -export([start_link/1]). -export([subscribe/1, unsubscribe/1, subscriptions/1, subscriptions/0, services/0, services/1, whois/1]). %% test/debug -export([call_module/3, state/1, uptime/1]). %%% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). %% Other callbacks. -export([send/1]). -include_lib("diameter/include/diameter.hrl"). -include("diameter_internal.hrl"). %% The states mirrored by peer_up/peer_down callbacks. -define(STATE_UP, up). -define(STATE_DOWN, down). -type op_state() :: ?STATE_UP | ?STATE_DOWN. %% The RFC 3539 watchdog states that are now maintained, albeit %% along with the old up/down. okay = up, else down. -define(WD_INITIAL, initial). -define(WD_OKAY, okay). -define(WD_SUSPECT, suspect). -define(WD_DOWN, down). -define(WD_REOPEN, reopen). -type wd_state() :: ?WD_INITIAL | ?WD_OKAY | ?WD_SUSPECT | ?WD_DOWN | ?WD_REOPEN. -define(DEFAULT_TC, 30000). %% RFC 3588 ch 2.1 -define(DEFAULT_TIMEOUT, 5000). %% for outgoing requests -define(RESTART_TC, 1000). %% if restart was this recent -define(RELAY, ?DIAMETER_DICT_RELAY). %% Used to be able to swap this with anything else dict-like but now %% rely on the fact that a service's #state{} record does not change %% in storing in it ?STATE table and not always going through the %% service process. In particular, rely on the fact that operations on %% a ?Dict don't change the handle to it. -define(Dict, diameter_dict). %% Table containing outgoing requests for which a reply has yet to be %% received. -define(REQUEST_TABLE, diameter_request). %% Maintains state in a table. In contrast to previously, a service's %% stat is not constant and is accessed outside of the service %% process. -define(STATE_TABLE, ?MODULE). %% The default sequence mask. -define(NOMASK, {0,32}). %% The default restrict_connections. -define(RESTRICT, nodes). %% Workaround for dialyzer's lack of understanding of match specs. -type match(T) :: T | '_' | '$1' | '$2' | '$3' | '$4'. %% State of service gen_server. -record(state, {id = now(), service_name, %% as passed to start_service/2, key in ?STATE_TABLE service :: #diameter_service{}, peerT = ets_new(peers) :: ets:tid(),%% #peer{} at start_fsm connT = ets_new(conns) :: ets:tid(),%% #conn{} at connection_up/reopen shared_peers = ?Dict:new(), %% Alias -> [{TPid, Caps}, ...] local_peers = ?Dict:new(), %% Alias -> [{TPid, Caps}, ...] monitor = false :: false | pid(), %% process to die with options :: [{sequence, diameter:sequence()} %% sequence mask | {restrict_connections, diameter:restriction()} | {share_peers, boolean()} %% broadcast peers to remote nodes? | {use_shared_peers, boolean()}]}).%% use broadcasted peers? %% shared_peers reflects the peers broadcast from remote nodes. Note %% that the state term itself doesn't change, which is relevant for %% the stateless application callbacks since the state is retrieved %% from ?STATE_TABLE from outside the service process. The pid in the %% service record is used to determine whether or not we need to call %% the process for a pick_peer callback. %% Record representing a watchdog process as implemented by %% diameter_watchdog. The term "peer" here is historical, made %% especially confusing by the fact that a peer_ref() in the %% documentation is the key of a #conn{} record, not a #peer{} record. %% The name is also unfortunate given the meaning of peer in the %% Diameter sense. -record(peer, {pid :: match(pid()), type :: match(connect | accept), ref :: match(reference()), %% key into diameter_config options :: match([diameter:transport_opt()]),%% from start_transport op_state = {?STATE_DOWN, ?WD_INITIAL} :: match({op_state(), wd_state()}), started = now(), %% at process start conn = false :: match(boolean() | pid())}). %% true at accepted, pid() at connection_up or reopen %% Record representing a peer process as implemented by %% diameter_peer_fsm. The term "conn" is historical. Despite the name %% here, comments refer to watchdog and peer processes, that are keys %% in #peer{} and #conn{} records respectively. To add to the %% confusion, a #request.transport is a peer process = key in a %% #conn{} record. The actual transport process (that the peer process %% knows about and that has a transport connection) isn't seen here. -record(conn, {pid :: pid(), apps :: [{0..16#FFFFFFFF, diameter:app_alias()}], %% {Id, Alias} caps :: #diameter_caps{}, started = now(), %% at process start peer :: pid()}). %% key into peerT %% Record stored in diameter_request for each outgoing request. -record(request, {from, %% arg 2 of handle_call/3 handler :: match(pid()), %% request process transport :: match(pid()), %% peer process caps :: match(#diameter_caps{}), app :: match(diameter:app_alias()),%% #diameter_app.alias dictionary :: match(module()), %% #diameter_app.dictionary module :: match([module() | list()]), %% #diameter_app.module filter :: match(diameter:peer_filter()), packet :: match(#diameter_packet{})}). %% Record call/4 options are parsed into. -record(options, {filter = none :: diameter:peer_filter(), extra = [] :: list(), timeout = ?DEFAULT_TIMEOUT :: 0..16#FFFFFFFF, detach = false :: boolean()}). %%% --------------------------------------------------------------------------- %%% # start(SvcName) %%% --------------------------------------------------------------------------- start(SvcName) -> diameter_service_sup:start_child(SvcName). start_link(SvcName) -> Options = [{spawn_opt, diameter_lib:spawn_opts(server, [])}], gen_server:start_link(?MODULE, [SvcName], Options). %% Put the arbitrary term SvcName in a list in case we ever want to %% send more than this and need to distinguish old from new. %%% --------------------------------------------------------------------------- %%% # stop(SvcName) %%% --------------------------------------------------------------------------- stop(SvcName) -> case whois(SvcName) of undefined -> {error, not_started}; Pid -> stop(call_service(Pid, stop), Pid) end. stop(ok, Pid) -> MRef = erlang:monitor(process, Pid), receive {'DOWN', MRef, process, _, _} -> ok end; stop(No, _) -> No. %%% --------------------------------------------------------------------------- %%% # start_transport(SvcName, {Ref, Type, Opts}) %%% --------------------------------------------------------------------------- start_transport(SvcName, {_,_,_} = T) -> call_service_by_name(SvcName, {start, T}). %%% --------------------------------------------------------------------------- %%% # stop_transport(SvcName, Refs) %%% --------------------------------------------------------------------------- stop_transport(_, []) -> ok; stop_transport(SvcName, [_|_] = Refs) -> call_service_by_name(SvcName, {stop, Refs}). %%% --------------------------------------------------------------------------- %%% # info(SvcName, Item) %%% --------------------------------------------------------------------------- info(SvcName, Item) -> case find_state(SvcName) of #state{} = S -> service_info(Item, S); false -> undefined end. %%% --------------------------------------------------------------------------- %%% # receive_message(TPid, Pkt, MessageData) %%% --------------------------------------------------------------------------- %% Handle an incoming Diameter message in the watchdog process. This %% used to come through the service process but this avoids that %% becoming a bottleneck. receive_message(TPid, Pkt, T) when is_pid(TPid) -> #diameter_packet{header = #diameter_header{is_request = R}} = Pkt, recv(R, (not R) andalso lookup_request(Pkt, TPid), TPid, Pkt, T). %% Incoming request ... recv(true, false, TPid, Pkt, T) -> try spawn(fun() -> recv_request(TPid, Pkt, T) end) catch error: system_limit = E -> %% discard ?LOG({error, E}, now()) end; %% ... answer to known request ... recv(false, #request{from = {_, Ref}, handler = Pid} = Req, _, Pkt, _) -> Pid ! {answer, Ref, Req, Pkt}; %% Note that failover could have happened prior to this message being %% received and triggering failback. That is, both a failover message %% and answer may be on their way to the handler process. In the worst %% case the request process gets notification of the failover and %% sends to the alternate peer before an answer arrives, so it's %% always the case that we can receive more than one answer after %% failover. The first answer received by the request process wins, %% any others are discarded. %% ... or not. recv(false, false, _, _, _) -> ok. %%% --------------------------------------------------------------------------- %%% # call(SvcName, App, Msg, Options) %%% --------------------------------------------------------------------------- call(SvcName, App, Msg, Options) when is_list(Options) -> Rec = make_options(Options), Ref = make_ref(), Caller = {self(), Ref}, Fun = fun() -> exit({Ref, call(SvcName, App, Msg, Rec, Caller)}) end, try spawn_monitor(Fun) of {_, MRef} -> recv(MRef, Ref, Rec#options.detach, false) catch error: system_limit = E -> {error, E} end. %% Don't rely on gen_server:call/3 for the timeout handling since it %% makes no guarantees about not leaving a reply message in the %% mailbox if we catch its exit at timeout. It currently *can* do so, %% which is also undocumented. recv(MRef, _, true, true) -> erlang:demonitor(MRef, [flush]), ok; recv(MRef, Ref, Detach, Sent) -> receive Ref -> %% send has been attempted recv(MRef, Ref, Detach, true); {'DOWN', MRef, process, _, Reason} -> call_rc(Reason, Ref, Sent) end. %% call/5 has returned ... call_rc({Ref, Ans}, Ref, _) -> Ans; %% ... or not. In this case failure/encode are documented. call_rc(_, _, Sent) -> {error, choose(Sent, failure, encode)}. %% call/5 %% %% In the process spawned for the outgoing request. call(SvcName, App, Msg, Opts, Caller) -> c(find_state(SvcName), App, Msg, Opts, Caller). c(#state{service_name = Svc, options = [{_, Mask} | _]} = S, App, Msg, Opts, Caller) -> case find_transport(App, Msg, Opts, S) of {_,_,_} = T -> send_request(T, Mask, Msg, Opts, Caller, Svc); false -> {error, no_connection}; {error, _} = No -> No end; c(false, _, _, _, _) -> {error, no_service}. %% find_state/1 find_state(SvcName) -> fs(ets:lookup(?STATE_TABLE, SvcName)). fs([#state{} = S]) -> S; fs([]) -> false. %% make_options/1 make_options(Options) -> lists:foldl(fun mo/2, #options{}, Options). mo({timeout, T}, Rec) when is_integer(T), 0 =< T -> Rec#options{timeout = T}; mo({filter, F}, #options{filter = none} = Rec) -> Rec#options{filter = F}; mo({filter, F}, #options{filter = {all, Fs}} = Rec) -> Rec#options{filter = {all, [F | Fs]}}; mo({filter, F}, #options{filter = F0} = Rec) -> Rec#options{filter = {all, [F0, F]}}; mo({extra, L}, #options{extra = X} = Rec) when is_list(L) -> Rec#options{extra = X ++ L}; mo(detach, Rec) -> Rec#options{detach = true}; mo(T, _) -> ?ERROR({invalid_option, T}). %%% --------------------------------------------------------------------------- %%% # subscribe(SvcName) %%% # unsubscribe(SvcName) %%% --------------------------------------------------------------------------- subscribe(SvcName) -> diameter_reg:add({?MODULE, subscriber, SvcName}). unsubscribe(SvcName) -> diameter_reg:del({?MODULE, subscriber, SvcName}). subscriptions(Pat) -> pmap(diameter_reg:match({?MODULE, subscriber, Pat})). subscriptions() -> subscriptions('_'). pmap(Props) -> lists:map(fun({{?MODULE, _, Name}, Pid}) -> {Name, Pid} end, Props). %%% --------------------------------------------------------------------------- %%% # services(Pattern) %%% --------------------------------------------------------------------------- services(Pat) -> pmap(diameter_reg:match({?MODULE, service, Pat})). services() -> services('_'). whois(SvcName) -> case diameter_reg:match({?MODULE, service, SvcName}) of [{_, Pid}] -> Pid; [] -> undefined end. %% =========================================================================== %% =========================================================================== state(Svc) -> call_service(Svc, state). uptime(Svc) -> call_service(Svc, uptime). %% call_module/3 call_module(Service, AppMod, Request) -> call_service(Service, {call_module, AppMod, Request}). %%% --------------------------------------------------------------------------- %%% # init([SvcName]) %%% --------------------------------------------------------------------------- init([SvcName]) -> process_flag(trap_exit, true), %% ensure terminate(shutdown, _) i(SvcName, diameter_reg:add_new({?MODULE, service, SvcName})). i(SvcName, true) -> {ok, i(SvcName)}; i(_, false) -> {stop, {shutdown, already_started}}. %%% --------------------------------------------------------------------------- %%% # handle_call(Req, From, State) %%% --------------------------------------------------------------------------- handle_call(state, _, S) -> {reply, S, S}; handle_call(uptime, _, #state{id = T} = S) -> {reply, diameter_lib:now_diff(T), S}; %% Start a transport. handle_call({start, {Ref, Type, Opts}}, _From, S) -> {reply, start(Ref, {Type, Opts}, S), S}; %% Stop transports. handle_call({stop, Refs}, _From, S) -> shutdown(Refs, S), {reply, ok, S}; %% pick_peer with mutable state handle_call({pick_peer, Local, Remote, App}, _From, S) -> #diameter_app{mutable = true} = App, %% assert {reply, pick_peer(Local, Remote, self(), S#state.service_name, App), S}; handle_call({call_module, AppMod, Req}, From, S) -> call_module(AppMod, Req, From, S); handle_call(stop, _From, S) -> shutdown(service, S), {stop, normal, ok, S}; %% The server currently isn't guaranteed to be dead when the caller %% gets the reply. We deal with this in the call to the server, %% stating a monitor that waits for DOWN before returning. handle_call(Req, From, S) -> unexpected(handle_call, [Req, From], S), {reply, nok, S}. %%% --------------------------------------------------------------------------- %%% # handle_cast(Req, State) %%% --------------------------------------------------------------------------- handle_cast(Req, S) -> unexpected(handle_cast, [Req], S), {noreply, S}. %%% --------------------------------------------------------------------------- %%% # handle_info(Req, State) %%% --------------------------------------------------------------------------- handle_info(T, #state{} = S) -> case transition(T,S) of ok -> {noreply, S}; {stop, Reason} -> {stop, {shutdown, Reason}, S} end. %% transition/2 %% Peer process is telling us to start a new accept process. transition({accepted, Pid, TPid}, S) -> accepted(Pid, TPid, S), ok; %% Peer process has a new open connection. transition({connection_up, Pid, T}, S) -> connection_up(Pid, T, S), ok; %% Watchdog has a new connection that will be opened after DW[RA] %% exchange. This message was added long after connection_up, to %% communicate the information as soon as it's available. Leave %% connection_up as is it for now, duplicated information and all. transition({reopen, Pid, T}, S) -> reopen(Pid, T, S), ok; %% Watchdog has left state OKAY. transition({connection_down, Pid}, S) -> connection_down(Pid, S), ok; %% Watchdog has returned to state OKAY. transition({connection_up, Pid}, S) -> connection_up(Pid, S), ok; %% Accepting transport has lost connectivity. transition({close, Pid}, S) -> close(Pid, S), ok; %% Connecting transport is being restarted by watchdog. transition({reconnect, Pid}, S) -> reconnect(Pid, S), ok; %% Watchdog is sending notification of a state transition. Note that %% the connection_up/down messages pre-date this message and are still %% used. A watchdog message will follow these and communicate the same %% state as was set in handling connection_up/down. transition({watchdog, Pid, {TPid, From, To}}, #state{service_name = SvcName, peerT = PeerT}) -> #peer{ref = Ref, type = T, options = Opts, op_state = {OS,_}} = P = fetch(PeerT, Pid), insert(PeerT, P#peer{op_state = {OS, To}}), send_event(SvcName, {watchdog, Ref, TPid, {From, To}, {T, Opts}}), ok; %% Death of a watchdog process (#peer.pid) results in the removal of %% it's peer and any associated conn record when 'DOWN' is received %% (after this) but the states will be {?STATE_UP, ?WD_DOWN} for a %% short time. (No real problem since ?WD_* is only used in %% service_info.) We set ?WD_OKAY as a consequence of connection_up %% since we know a watchdog is coming. We can't set anything at %% connection_down since we don't know if the subsequent watchdog %% message will be ?WD_DOWN or ?WD_SUSPECT. We don't (yet) set %% ?STATE_* as a consequence of a watchdog message since this requires %% changing some of the matching on ?STATE_*. %% %% Death of a peer process process (#conn.pid, #peer.conn) results in %% connection_down followed by watchdog ?WD_DOWN. The latter doesn't %% result in the conn record being deleted since 'DOWN' from death of %% its watchdog doesn't (yet) deal with the record having been %% removed. %% Monitor process has died. Just die with a reason that tells %% diameter_config about the happening. If a cleaner shutdown is %% required then someone should stop us. transition({'DOWN', MRef, process, _, Reason}, #state{monitor = MRef}) -> {stop, {monitor, Reason}}; %% Local watchdog process has died. transition({'DOWN', _, process, Pid, Reason}, S) when node(Pid) == node() -> peer_down(Pid, Reason, S), ok; %% Remote service wants to know about shared peers. transition({service, Pid}, S) -> share_peers(Pid, S), ok; %% Remote service is communicating a shared peer. transition({peer, TPid, Aliases, Caps}, S) -> remote_peer_up(TPid, Aliases, Caps, S), ok; %% Remote peer process has died. transition({'DOWN', _, process, TPid, _}, S) -> remote_peer_down(TPid, S), ok; %% Restart after tc expiry. transition({tc_timeout, T}, S) -> tc_timeout(T, S), ok; %% Request process is telling us it may have missed a failover message %% after a transport went down and the service process looked up %% outstanding requests. transition({failover, TRef, Seqs}, S) -> failover(TRef, Seqs, S), ok; transition(Req, S) -> unexpected(handle_info, [Req], S), ok. %%% --------------------------------------------------------------------------- %%% # terminate(Reason, State) %%% --------------------------------------------------------------------------- terminate(Reason, #state{service_name = Name} = S) -> send_event(Name, stop), ets:delete(?STATE_TABLE, Name), shutdown == Reason %% application shutdown andalso shutdown(application, S). %%% --------------------------------------------------------------------------- %%% # code_change(FromVsn, State, Extra) %%% --------------------------------------------------------------------------- code_change(FromVsn, #state{service_name = SvcName, service = #diameter_service{applications = Apps}} = S, Extra) -> lists:foreach(fun(A) -> code_change(FromVsn, SvcName, Extra, A) end, Apps), {ok, S}. code_change(FromVsn, SvcName, Extra, #diameter_app{alias = Alias} = A) -> {ok, S} = cb(A, code_change, [FromVsn, mod_state(Alias), Extra, SvcName]), mod_state(Alias, S). %% =========================================================================== %% =========================================================================== unexpected(F, A, #state{service_name = Name}) -> ?UNEXPECTED(F, A ++ [Name]). cb([_|_] = M, F, A) -> eval(M, F, A); cb(Rec, F, A) -> {_, M} = app(Rec), eval(M, F, A). app(#request{app = A, module = M}) -> {A,M}; app(#diameter_app{alias = A, module = M}) -> {A,M}. eval([M|X], F, A) -> apply(M, F, A ++ X). %% Callback with state. state_cb(#diameter_app{mutable = false, init_state = S}, {ModX, F, A}) -> eval(ModX, F, A ++ [S]); state_cb(#diameter_app{mutable = true, alias = Alias}, {_,_,_} = MFA) -> state_cb(MFA, Alias); state_cb({ModX,F,A}, Alias) when is_list(ModX) -> eval(ModX, F, A ++ [mod_state(Alias)]). choose(true, X, _) -> X; choose(false, _, X) -> X. ets_new(Tbl) -> ets:new(Tbl, [{keypos, 2}]). insert(Tbl, Rec) -> ets:insert(Tbl, Rec), Rec. %% Using the process dictionary for the callback state was initially %% just a way to make what was horrendous trace (big state record and %% much else everywhere) somewhat more readable. There's not as much %% need for it now but it's no worse (except possibly that we don't %% see the table identifier being passed around) than an ets table so %% keep it. mod_state(Alias) -> get({?MODULE, mod_state, Alias}). mod_state(Alias, ModS) -> put({?MODULE, mod_state, Alias}, ModS). %%% --------------------------------------------------------------------------- %%% # shutdown/2 %%% --------------------------------------------------------------------------- %% remove_transport: ask watchdogs to terminate their transport. shutdown(Refs, #state{peerT = PeerT}) when is_list(Refs) -> ets:foldl(fun(P,ok) -> sp(P, Refs), ok end, ok, PeerT); %% application/service shutdown: ask transports to terminate themselves. shutdown(Reason, #state{peerT = PeerT}) -> %% A transport might not be alive to receive the shutdown request %% but give those that are a chance to shutdown gracefully. shutdown(conn, Reason, PeerT), %% Kill the watchdogs explicitly in case there was no transport. shutdown(peer, Reason, PeerT). %% sp/2 sp(#peer{ref = Ref, pid = Pid}, Refs) -> lists:member(Ref, Refs) andalso (Pid ! {shutdown, self()}). %% 'DOWN' cleans up %% shutdown/3 shutdown(Who, Reason, T) -> diameter_lib:wait(ets:foldl(fun(X,A) -> shutdown(Who, X, Reason, A) end, [], T)). shutdown(conn, #peer{pid = Pid, op_state = {?STATE_UP, _}, conn = TPid}, Reason, Acc) -> TPid ! {shutdown, Pid, Reason}, [TPid | Acc]; shutdown(peer, #peer{pid = Pid}, _Reason, Acc) when is_pid(Pid) -> exit(Pid, shutdown), [Pid | Acc]; shutdown(_, #peer{}, _, Acc) -> Acc. %%% --------------------------------------------------------------------------- %%% # call_service/2 %%% --------------------------------------------------------------------------- call_service(Pid, Req) when is_pid(Pid) -> cs(Pid, Req); call_service(SvcName, Req) -> call_service_by_name(SvcName, Req). call_service_by_name(SvcName, Req) -> cs(whois(SvcName), Req). cs(Pid, Req) when is_pid(Pid) -> try gen_server:call(Pid, Req, infinity) catch E: Reason when E == exit -> {error, {E, Reason}} end; cs(undefined, _) -> {error, no_service}. %%% --------------------------------------------------------------------------- %%% # i/1 %%% %%% Output: #state{} %%% --------------------------------------------------------------------------- %% Intialize the state of a service gen_server. i(SvcName) -> %% Split the config into a server state and a list of transports. {#state{} = S, CL} = lists:foldl(fun cfg_acc/2, {false, []}, diameter_config:lookup(SvcName)), %% Publish the state in order to be able to access it outside of %% the service process. Originally table identifiers were only %% known to the service process but we now want to provide the %% option of application callbacks being 'stateless' in order to %% avoid having to go through a common process. (Eg. An agent that %% sends a request for every incoming request.) true = ets:insert_new(?STATE_TABLE, S), %% Start fsms for each transport. send_event(SvcName, start), lists:foreach(fun(T) -> start_fsm(T,S) end, CL), init_shared(S), S. cfg_acc({SvcName, #diameter_service{applications = Apps} = Rec, Opts}, {false, Acc}) -> lists:foreach(fun init_mod/1, Apps), S = #state{service_name = SvcName, service = Rec#diameter_service{pid = self()}, monitor = mref(get_value(monitor, Opts)), options = service_options(Opts)}, {S, Acc}; cfg_acc({_Ref, Type, _Opts} = T, {S, Acc}) when Type == connect; Type == listen -> {S, [T | Acc]}. service_options(Opts) -> [{sequence, proplists:get_value(sequence, Opts, ?NOMASK)}, {share_peers, get_value(share_peers, Opts)}, {use_shared_peers, get_value(use_shared_peers, Opts)}, {restrict_connections, proplists:get_value(restrict_connections, Opts, ?RESTRICT)}]. %% The order of options is significant since we match against the list. mref(false = No) -> No; mref(P) -> erlang:monitor(process, P). init_shared(#state{options = [_, _, {_, true} | _], service_name = Svc}) -> diameter_peer:notify(Svc, {service, self()}); init_shared(#state{options = [_, _, {_, false} | _]}) -> ok. init_mod(#diameter_app{alias = Alias, init_state = S}) -> mod_state(Alias, S). start_fsm({Ref, Type, Opts}, S) -> start(Ref, {Type, Opts}, S). get_value(Key, Vs) -> {_, V} = lists:keyfind(Key, 1, Vs), V. %%% --------------------------------------------------------------------------- %%% # start/3 %%% --------------------------------------------------------------------------- %% If the initial start/3 at service/transport start succeeds then %% subsequent calls to start/4 on the same service will also succeed %% since they involve the same call to merge_service/2. We merge here %% rather than earlier since the service may not yet be configured %% when the transport is configured. start(Ref, {T, Opts}, S) when T == connect; T == listen -> try {ok, start(Ref, type(T), Opts, S)} catch ?FAILURE(Reason) -> {error, Reason} end. %% TODO: don't actually raise any errors yet %% There used to be a difference here between the handling of %% configured listening and connecting transports but now we simply %% tell the transport_module to start an accepting or connecting %% process respectively, the transport implementation initiating %% listening on a port as required. type(listen) -> accept; type(accept) -> listen; type(connect = T) -> T. %% start/4 start(Ref, Type, Opts, #state{peerT = PeerT, connT = ConnT, options = SvcOpts, service_name = SvcName, service = Svc}) when Type == connect; Type == accept -> Pid = s(Type, Ref, {ConnT, Opts, SvcName, SvcOpts, merge_service(Opts, Svc)}), insert(PeerT, #peer{pid = Pid, type = Type, ref = Ref, options = Opts}), Pid. %% Note that the service record passed into the watchdog is the merged %% record so that each watchdog may get a different record. This %% record is what is passed back into application callbacks. s(Type, Ref, T) -> {_MRef, Pid} = diameter_watchdog:start({Type, Ref}, T), Pid. %% merge_service/2 merge_service(Opts, Svc) -> lists:foldl(fun ms/2, Svc, Opts). %% Limit the applications known to the fsm to those in the 'apps' %% option. That this might be empty is checked by the fsm. It's not %% checked at config-time since there's no requirement that the %% service be configured first. (Which could be considered a bit odd.) ms({applications, As}, #diameter_service{applications = Apps} = S) when is_list(As) -> S#diameter_service{applications = [A || A <- Apps, lists:member(A#diameter_app.alias, As)]}; %% The fact that all capabilities can be configured on the transports %% means that the service doesn't necessarily represent a single %% locally implemented Diameter peer as identified by Origin-Host: a %% transport can configure its own Origin-Host. This means that the %% service little more than a placeholder for default capabilities %% plus a list of applications that individual transports can choose %% to support (or not). ms({capabilities, Opts}, #diameter_service{capabilities = Caps0} = Svc) when is_list(Opts) -> %% make_caps has already succeeded in diameter_config so it will succeed %% again here. {ok, Caps} = diameter_capx:make_caps(Caps0, Opts), Svc#diameter_service{capabilities = Caps}; ms(_, Svc) -> Svc. %%% --------------------------------------------------------------------------- %%% # accepted/3 %%% --------------------------------------------------------------------------- accepted(Pid, _TPid, #state{peerT = PeerT} = S) -> #peer{ref = Ref, type = accept = T, conn = false, options = Opts} = P = fetch(PeerT, Pid), insert(PeerT, P#peer{conn = true}), %% mark replacement as started start(Ref, T, Opts, S). %% start new watchdog fetch(Tid, Key) -> [T] = ets:lookup(Tid, Key), T. %%% --------------------------------------------------------------------------- %%% # connection_up/3 %%% --------------------------------------------------------------------------- %% Watchdog process has reached state OKAY. connection_up(Pid, {TPid, {Caps, SApps, Pkt}}, #state{peerT = PeerT, connT = ConnT} = S) -> P = fetch(PeerT, Pid), C = #conn{pid = TPid, apps = SApps, caps = Caps, peer = Pid}, insert(ConnT, C), connection_up([Pkt], P#peer{conn = TPid}, C, S). %%% --------------------------------------------------------------------------- %%% # reopen/3 %%% --------------------------------------------------------------------------- %% Note that this connection_up/3 rewrites the same #conn{} now %% written here. Both do so in case reopen has not happened in old %% code. reopen(Pid, {TPid, {Caps, SApps, _Pkt}}, #state{peerT = PeerT, connT = ConnT}) -> P = fetch(PeerT, Pid), C = #conn{pid = TPid, apps = SApps, caps = Caps, peer = Pid}, insert(ConnT, C), #peer{op_state = {?STATE_DOWN, _}} = P, insert(PeerT, P#peer{op_state = {?STATE_DOWN, ?WD_REOPEN}, conn = TPid}). %%% --------------------------------------------------------------------------- %%% # connection_up/2 %%% --------------------------------------------------------------------------- %% Peer process has transitioned back into the open state. Note that there %% has been no new capabilties exchange in this case. connection_up(Pid, #state{peerT = PeerT, connT = ConnT} = S) -> #peer{conn = TPid} = P = fetch(PeerT, Pid), C = fetch(ConnT, TPid), connection_up([], P, C, S). %% connection_up/4 connection_up(T, P, C, #state{peerT = PeerT, local_peers = LDict, service_name = SvcName, service = #diameter_service{applications = Apps}} = S) -> #peer{conn = TPid, op_state = {?STATE_DOWN, _}} = P, #conn{apps = SApps, caps = Caps} = C, insert(PeerT, P#peer{op_state = {?STATE_UP, ?WD_OKAY}}), request_peer_up(TPid), insert_local_peer(SApps, {{TPid, Caps}, {SvcName, Apps}}, LDict), report_status(up, P, C, S, T). insert_local_peer(SApps, T, LDict) -> lists:foldl(fun(A,D) -> ilp(A, T, D) end, LDict, SApps). ilp({Id, Alias}, {TC, SA}, LDict) -> init_conn(Id, Alias, TC, SA), ?Dict:append(Alias, TC, LDict). init_conn(Id, Alias, {TPid, _} = TC, {SvcName, Apps}) -> #diameter_app{module = ModX, id = Id} %% assert = find_app(Alias, Apps), peer_cb({ModX, peer_up, [SvcName, TC]}, Alias) orelse exit(TPid, kill). %% fake transport failure %% find_app/2 find_app(Alias, Apps) -> lists:keyfind(Alias, #diameter_app.alias, Apps). %% Don't bring down the service (and all associated connections) %% regardless of what happens. peer_cb(MFA, Alias) -> try state_cb(MFA, Alias) of ModS -> mod_state(Alias, ModS), true catch E:R -> diameter_lib:error_report({failure, {E, R, Alias, ?STACK}}, MFA), false end. %%% --------------------------------------------------------------------------- %%% # connection_down/2 %%% --------------------------------------------------------------------------- %% Watchdog has transitioned out of state OKAY. connection_down(Pid, #state{peerT = PeerT, connT = ConnT} = S) -> #peer{op_state = {?STATE_UP, WS}, %% assert conn = TPid} = P = fetch(PeerT, Pid), C = fetch(ConnT, TPid), insert(PeerT, P#peer{op_state = {?STATE_DOWN, WS}}), connection_down(P,C,S). %% connection_down/3 connection_down(#peer{op_state = {?STATE_DOWN, _}}, _, _) -> ok; connection_down(#peer{conn = TPid, op_state = {?STATE_UP, _}} = P, #conn{caps = Caps, apps = SApps} = C, #state{service_name = SvcName, service = #diameter_service{applications = Apps}, local_peers = LDict} = S) -> report_status(down, P, C, S, []), remove_local_peer(SApps, {{TPid, Caps}, {SvcName, Apps}}, LDict), request_peer_down(TPid, S). remove_local_peer(SApps, T, LDict) -> lists:foldl(fun(A,D) -> rlp(A, T, D) end, LDict, SApps). rlp({Id, Alias}, {TC, SA}, LDict) -> L = ?Dict:fetch(Alias, LDict), down_conn(Id, Alias, TC, SA), ?Dict:store(Alias, lists:delete(TC, L), LDict). down_conn(Id, Alias, TC, {SvcName, Apps}) -> #diameter_app{module = ModX, id = Id} %% assert = find_app(Alias, Apps), peer_cb({ModX, peer_down, [SvcName, TC]}, Alias). %%% --------------------------------------------------------------------------- %%% # peer_down/3 %%% --------------------------------------------------------------------------- %% Watchdog process has died. peer_down(Pid, Reason, #state{peerT = PeerT} = S) -> P = fetch(PeerT, Pid), ets:delete_object(PeerT, P), closed(Reason, P, S), restart(P,S), peer_down(P,S). %% Send an event at connection establishment failure. closed({shutdown, {close, _TPid, Reason}}, #peer{op_state = {?STATE_DOWN, _}, ref = Ref, type = Type, options = Opts}, #state{service_name = SvcName}) -> send_event(SvcName, {closed, Ref, Reason, {type(Type), Opts}}); closed(_, _, _) -> ok. %% The watchdog has never reached OKAY ... peer_down(#peer{conn = B}, _) when is_boolean(B) -> ok; %% ... or maybe it has. peer_down(#peer{conn = TPid} = P, #state{connT = ConnT} = S) -> #conn{} = C = fetch(ConnT, TPid), ets:delete_object(ConnT, C), connection_down(P,C,S). %% restart/2 restart(P,S) -> q_restart(restart(P), S). %% restart/1 %% Always try to reconnect. restart(#peer{ref = Ref, type = connect = T, options = Opts, started = Time}) -> {Time, {Ref, T, Opts}}; %% Transport connection hasn't yet been accepted ... restart(#peer{ref = Ref, type = accept = T, options = Opts, conn = false, started = Time}) -> {Time, {Ref, T, Opts}}; %% ... or it has: a replacement has already been spawned. restart(#peer{type = accept}) -> false. %% q_restart/2 %% Start the reconnect timer. q_restart({Time, {_Ref, Type, Opts} = T}, S) -> start_tc(tc(Time, default_tc(Type, Opts)), T, S); q_restart(false, _) -> ok. %% RFC 3588, 2.1: %% %% When no transport connection exists with a peer, an attempt to %% connect SHOULD be periodically made. This behavior is handled via %% the Tc timer, whose recommended value is 30 seconds. There are %% certain exceptions to this rule, such as when a peer has terminated %% the transport connection stating that it does not wish to %% communicate. default_tc(connect, Opts) -> proplists:get_value(reconnect_timer, Opts, ?DEFAULT_TC); default_tc(accept, _) -> 0. %% Bound tc below if the watchdog was restarted recently to avoid %% continuous restarted in case of faulty config or other problems. tc(Time, Tc) -> choose(Tc > ?RESTART_TC orelse timer:now_diff(now(), Time) > 1000*?RESTART_TC, Tc, ?RESTART_TC). start_tc(0, T, S) -> tc_timeout(T, S); start_tc(Tc, T, _) -> erlang:send_after(Tc, self(), {tc_timeout, T}). %% tc_timeout/2 tc_timeout({Ref, _Type, _Opts} = T, #state{service_name = SvcName} = S) -> tc(diameter_config:have_transport(SvcName, Ref), T, S). tc(true, {Ref, Type, Opts}, #state{service_name = SvcName} = S) -> send_event(SvcName, {reconnect, Ref, Opts}), start(Ref, Type, Opts, S); tc(false = No, _, _) -> %% removed No. %%% --------------------------------------------------------------------------- %%% # close/2 %%% --------------------------------------------------------------------------- %% The watchdog doesn't start a new fsm in the accept case, it %% simply stays alive until someone tells it to die in order for %% another watchdog to be able to detect that it should transition %% from initial into reopen rather than okay. That someone is either %% the accepting watchdog upon reception of a CER from the previously %% connected peer, or us after reconnect_timer timeout. close(Pid, #state{service_name = SvcName, peerT = PeerT}) -> #peer{pid = Pid, type = accept, ref = Ref, options = Opts} = fetch(PeerT, Pid), c(Pid, diameter_config:have_transport(SvcName, Ref), Opts). %% Tell watchdog to (maybe) die later ... c(Pid, true, Opts) -> Tc = proplists:get_value(reconnect_timer, Opts, 2*?DEFAULT_TC), erlang:send_after(Tc, Pid, close); %% ... or now. c(Pid, false, _Opts) -> Pid ! close. %% The RFC's only document the behaviour of Tc, our reconnect_timer, %% for the establishment of connections but we also give %% reconnect_timer semantics for a listener, being the time within %% which a new connection attempt is expected of a connecting peer. %% The value should be greater than the peer's Tc + jitter. %%% --------------------------------------------------------------------------- %%% # reconnect/2 %%% --------------------------------------------------------------------------- reconnect(Pid, #state{service_name = SvcName, peerT = PeerT}) -> #peer{ref = Ref, type = connect, options = Opts} = fetch(PeerT, Pid), send_event(SvcName, {reconnect, Ref, Opts}). %%% --------------------------------------------------------------------------- %%% # call_module/4 %%% --------------------------------------------------------------------------- %% Backwards compatibility and never documented/advertised. May be %% removed. call_module(Mod, Req, From, #state{service = #diameter_service{applications = Apps}, service_name = Svc} = S) -> case cm([A || A <- Apps, Mod == hd(A#diameter_app.module)], Req, From, Svc) of {reply = T, RC} -> {T, RC, S}; noreply = T -> {T, S}; Reason -> {reply, {error, Reason}, S} end. cm([#diameter_app{module = ModX, alias = Alias}], Req, From, Svc) -> MFA = {ModX, handle_call, [Req, From, Svc]}, try state_cb(MFA, Alias) of {noreply = T, ModS} -> mod_state(Alias, ModS), T; {reply = T, RC, ModS} -> mod_state(Alias, ModS), {T, RC}; T -> diameter_lib:error_report({invalid, T}, MFA), invalid catch E: Reason -> diameter_lib:error_report({failure, {E, Reason, ?STACK}}, MFA), failure end; cm([], _, _, _) -> unknown; cm([_,_|_], _, _, _) -> multiple. %%% --------------------------------------------------------------------------- %%% # send_request/6 %%% --------------------------------------------------------------------------- %% Send an outgoing request in its dedicated process. %% %% Note that both encode of the outgoing request and of the received %% answer happens in this process. It's also this process that replies %% to the caller. The service process only handles the state-retaining %% callbacks. %% %% The mod field of the #diameter_app{} here includes any extra %% arguments passed to diameter:call/2. send_request({TPid, Caps, App} = T, Mask, Msg, Opts, Caller, SvcName) -> #diameter_app{module = ModX} = App, Pkt = make_prepare_packet(Mask, Msg), send_req(cb(ModX, prepare_request, [Pkt, SvcName, {TPid, Caps}]), Pkt, T, Opts, Caller, SvcName, []). send_req({send, P}, Pkt, T, Opts, Caller, SvcName, Fs) -> send_req(make_request_packet(P, Pkt), T, Opts, Caller, SvcName, Fs); send_req({discard, Reason} , _, _, _, _, _, _) -> {error, Reason}; send_req(discard, _, _, _, _, _, _) -> {error, discarded}; send_req({eval_packet, RC, F}, Pkt, T, Opts, Caller, SvcName, Fs) -> send_req(RC, Pkt, T, Opts, Caller, SvcName, [F|Fs]); send_req(E, _, {_, _, App}, _, _, _, _) -> ?ERROR({invalid_return, prepare_request, App, E}). %% make_prepare_packet/2 %% %% Turn an outgoing request as passed to call/4 into a diameter_packet %% record in preparation for a prepare_request callback. make_prepare_packet(_, Bin) when is_binary(Bin) -> #diameter_packet{header = diameter_codec:decode_header(Bin), bin = Bin}; make_prepare_packet(Mask, #diameter_packet{msg = [#diameter_header{} = Hdr | Avps]} = Pkt) -> Pkt#diameter_packet{msg = [make_prepare_header(Mask, Hdr) | Avps]}; make_prepare_packet(Mask, #diameter_packet{header = Hdr} = Pkt) -> Pkt#diameter_packet{header = make_prepare_header(Mask, Hdr)}; make_prepare_packet(Mask, Msg) -> make_prepare_packet(Mask, #diameter_packet{msg = Msg}). %% make_prepare_header/2 make_prepare_header(Mask, undefined) -> Seq = diameter_session:sequence(Mask), make_prepare_header(#diameter_header{end_to_end_id = Seq, hop_by_hop_id = Seq}); make_prepare_header(Mask, #diameter_header{end_to_end_id = undefined, hop_by_hop_id = undefined} = H) -> Seq = diameter_session:sequence(Mask), make_prepare_header(H#diameter_header{end_to_end_id = Seq, hop_by_hop_id = Seq}); make_prepare_header(Mask, #diameter_header{end_to_end_id = undefined} = H) -> Seq = diameter_session:sequence(Mask), make_prepare_header(H#diameter_header{end_to_end_id = Seq}); make_prepare_header(Mask, #diameter_header{hop_by_hop_id = undefined} = H) -> Seq = diameter_session:sequence(Mask), make_prepare_header(H#diameter_header{hop_by_hop_id = Seq}); make_prepare_header(_, Hdr) -> make_prepare_header(Hdr). %% make_prepare_header/1 make_prepare_header(#diameter_header{version = undefined} = Hdr) -> make_prepare_header(Hdr#diameter_header{version = ?DIAMETER_VERSION}); make_prepare_header(#diameter_header{} = Hdr) -> Hdr; make_prepare_header(T) -> ?ERROR({invalid_header, T}). %% make_request_packet/2 %% %% Reconstruct a diameter_packet from the return value of %% prepare_request or prepare_retransmit callback. make_request_packet(Bin, _) when is_binary(Bin) -> make_prepare_packet(false, Bin); make_request_packet(#diameter_packet{msg = [#diameter_header{} | _]} = Pkt, _) -> Pkt; %% Returning a diameter_packet with no header from a prepare_request %% or prepare_retransmit callback retains the header passed into it. %% This is primarily so that the end to end and hop by hop identifiers %% are retained. make_request_packet(#diameter_packet{header = Hdr} = Pkt, #diameter_packet{header = Hdr0}) -> Pkt#diameter_packet{header = fold_record(Hdr0, Hdr)}; make_request_packet(Msg, Pkt) -> Pkt#diameter_packet{msg = Msg}. %% fold_record/2 fold_record(undefined, R) -> R; fold_record(Rec, R) -> diameter_lib:fold_tuple(2, Rec, R). %% send_req/6 send_req(Pkt, {TPid, Caps, App}, Opts, Caller, SvcName, Fs) -> #diameter_app{alias = Alias, dictionary = Dict, module = ModX, options = [{answer_errors, AE} | _]} = App, EPkt = encode(Dict, Pkt, Fs), #options{filter = Filter, timeout = Timeout} = Opts, Req = #request{packet = Pkt, from = Caller, handler = self(), transport = TPid, caps = Caps, app = Alias, filter = Filter, dictionary = Dict, module = ModX}, try TRef = send_request(TPid, EPkt, Req, Timeout), ack(Caller), handle_answer(SvcName, AE, recv_answer(Timeout, SvcName, {TRef, Req})) after erase_request(EPkt) end. %% Tell caller a send has been attempted. ack({Pid, Ref}) -> Pid ! Ref. %% recv_answer/3 recv_answer(Timeout, SvcName, {TRef, #request{from = {_, Ref}, packet = RPkt} = Req} = T) -> %% Matching on TRef below ensures we ignore messages that pertain %% to a previous transport prior to failover. The answer message %% includes the #request{} since it's not necessarily Req; that %% is, from the last peer to which we've transmitted. receive {answer = A, Ref, Rq, Pkt} -> %% Answer from peer {A, Rq, Pkt}; {timeout = Reason, TRef, _} -> %% No timely reply {error, Req, Reason}; {failover = Reason, TRef, false} -> %% No alternate peer {error, Req, Reason}; {failover, TRef, Transport} -> %% Resend to alternate peer try_retransmit(Timeout, SvcName, Req, Transport); {failover, TRef} -> %% May have missed failover notification Seqs = diameter_codec:sequence_numbers(RPkt), Pid = whois(SvcName), is_pid(Pid) andalso (Pid ! {failover, TRef, Seqs}), recv_answer(Timeout, SvcName, T) end. %% Note that failover starts a new timer and that expiry of an old %% timer value is ignored. This means that an answer could be accepted %% from a peer after timeout in the case of failover. try_retransmit(Timeout, SvcName, Req, Transport) -> try retransmit(Transport, Req, SvcName, Timeout) of T -> recv_answer(Timeout, SvcName, T) catch ?FAILURE(Reason) -> {error, Req, Reason} end. %% handle_error/3 handle_error(Req, Reason, SvcName) -> #request{module = ModX, packet = Pkt, transport = TPid, caps = Caps} = Req, cb(ModX, handle_error, [Reason, msg(Pkt), SvcName, {TPid, Caps}]). msg(#diameter_packet{msg = undefined, bin = Bin}) -> Bin; msg(#diameter_packet{msg = Msg}) -> Msg. %% encode/3 encode(Dict, Pkt, Fs) -> P = encode(Dict, Pkt), eval_packet(P, Fs), P. %% encode/2 %% Note that prepare_request can return a diameter_packet containing %% header or transport_data. Even allow the returned record to contain %% an encoded binary. This isn't the usual case but could some in %% handy, for test at least. (For example, to send garbage.) %% The normal case: encode the returned message. encode(Dict, #diameter_packet{msg = Msg, bin = undefined} = Pkt) -> D = pick_dictionary([Dict, ?BASE], Msg), diameter_codec:encode(D, Pkt); %% Callback has returned an encoded binary: just send. encode(_, #diameter_packet{} = Pkt) -> Pkt. %% pick_dictionary/2 %% Pick the first dictionary that declares the application id in the %% specified header. pick_dictionary(Ds, [#diameter_header{application_id = Id} | _]) -> pd(Ds, fun(D) -> Id = D:id() end); %% Pick the first dictionary that knows the specified message name. pick_dictionary(Ds, [MsgName|_]) -> pd(Ds, fun(D) -> D:msg2rec(MsgName) end); %% Pick the first dictionary that knows the name of the specified %% message record. pick_dictionary(Ds, Rec) -> Name = element(1, Rec), pd(Ds, fun(D) -> D:rec2msg(Name) end). pd([D|Ds], F) -> try F(D), D catch error:_ -> pd(Ds, F) end; pd([], _) -> ?ERROR(no_dictionary). %% send_request/4 send_request(TPid, #diameter_packet{bin = Bin} = Pkt, Req, Timeout) when node() == node(TPid) -> %% Store the outgoing request before sending to avoid a race with %% reply reception. TRef = store_request(TPid, Bin, Req, Timeout), send(TPid, Pkt), TRef; %% Send using a remote transport: spawn a process on the remote node %% to relay the answer. send_request(TPid, #diameter_packet{} = Pkt, Req, Timeout) -> TRef = erlang:start_timer(Timeout, self(), timeout), T = {TPid, Pkt, Req, Timeout, TRef}, spawn(node(TPid), ?MODULE, send, [T]), TRef. %% send/1 send({TPid, Pkt, #request{handler = Pid} = Req, Timeout, TRef}) -> Ref = send_request(TPid, Pkt, Req#request{handler = self()}, Timeout), Pid ! reref(receive T -> T end, Ref, TRef). reref({T, Ref, R}, Ref, TRef) -> {T, TRef, R}; reref(T, _, _) -> T. %% send/2 send(Pid, Pkt) -> Pid ! {send, Pkt}. %% retransmit/4 retransmit({TPid, Caps, #diameter_app{alias = Alias} = App} = T, #request{app = Alias, packet = Pkt0} = Req, SvcName, Timeout) -> have_request(Pkt0, TPid) %% Don't failover to a peer we've andalso ?THROW(timeout), %% already sent to. #diameter_packet{header = Hdr0} = Pkt0, Hdr = Hdr0#diameter_header{is_retransmitted = true}, Pkt = Pkt0#diameter_packet{header = Hdr}, resend_req(cb(App, prepare_retransmit, [Pkt, SvcName, {TPid, Caps}]), T, Req#request{packet = Pkt}, Timeout, []). resend_req({send, P}, T, #request{packet = Pkt} = Req, Timeout, Fs) -> retransmit(make_request_packet(P, Pkt), T, Req, Timeout, Fs); resend_req({discard, Reason}, _, _, _, _) -> ?THROW(Reason); resend_req(discard, _, _, _, _) -> ?THROW(discarded); resend_req({eval_packet, RC, F}, T, Req, Timeout, Fs) -> resend_req(RC, T, Req, Timeout, [F|Fs]); resend_req(T, {_, _, App}, _, _, _) -> ?ERROR({invalid_return, prepare_retransmit, App, T}). %% retransmit/6 retransmit(Pkt, {TPid, Caps, _}, #request{dictionary = D} = Req0, Tmo, Fs) -> EPkt = encode(D, Pkt, Fs), Req = Req0#request{transport = TPid, packet = Pkt, caps = Caps}, ?LOG(retransmission, Req), TRef = send_request(TPid, EPkt, Req, Tmo), {TRef, Req}. %% store_request/4 store_request(TPid, Bin, Req, Timeout) -> Seqs = diameter_codec:sequence_numbers(Bin), TRef = erlang:start_timer(Timeout, self(), timeout), ets:insert(?REQUEST_TABLE, {Seqs, Req, TRef}), ets:member(?REQUEST_TABLE, TPid) orelse (self() ! {failover, TRef}), %% possibly missed failover TRef. %% lookup_request/2 lookup_request(Msg, TPid) when is_pid(TPid) -> lookup(Msg, TPid, '_'); lookup_request(Msg, TRef) when is_reference(TRef) -> lookup(Msg, '_', TRef). lookup(Msg, TPid, TRef) -> Seqs = diameter_codec:sequence_numbers(Msg), Spec = [{{Seqs, #request{transport = TPid, _ = '_'}, TRef}, [], ['$_']}], case ets:select(?REQUEST_TABLE, Spec) of [{_, Req, _}] -> Req; [] -> false end. %% erase_request/1 erase_request(Pkt) -> ets:delete(?REQUEST_TABLE, diameter_codec:sequence_numbers(Pkt)). %% match_requests/1 match_requests(TPid) -> Pat = {'_', #request{transport = TPid, _ = '_'}, '_'}, ets:select(?REQUEST_TABLE, [{Pat, [], ['$_']}]). %% have_request/2 have_request(Pkt, TPid) -> Seqs = diameter_codec:sequence_numbers(Pkt), Pat = {Seqs, #request{transport = TPid, _ = '_'}, '_'}, '$end_of_table' /= ets:select(?REQUEST_TABLE, [{Pat, [], ['$_']}], 1). %% request_peer_up/1 request_peer_up(TPid) -> ets:insert(?REQUEST_TABLE, {TPid}). %% request_peer_down/2 request_peer_down(TPid, S) -> ets:delete(?REQUEST_TABLE, TPid), lists:foreach(fun(T) -> failover(T,S) end, match_requests(TPid)). %% Note that a request process can store its request after failover %% notifications are sent here: store_request/4 sends the notification %% in that case. Note also that we'll send as many notifications to a %% given handler as there are peers its sent to. All but one of these %% will be ignored. %%% --------------------------------------------------------------------------- %%% recv_request/3 %%% --------------------------------------------------------------------------- recv_request(TPid, Pkt, {ConnT, SvcName, Apps, Mask}) -> try ets:lookup(ConnT, TPid) of [C] -> recv_request(C, TPid, Pkt, SvcName, Apps, Mask); [] -> %% transport has gone down ok catch error: badarg -> %% service has gone down (and taken table with it) ok end. %% recv_request/5 recv_request(#conn{apps = SApps, caps = Caps}, TPid, Pkt, SvcName, Apps, Mask) -> #diameter_caps{origin_host = {OH,_}, origin_realm = {OR,_}} = Caps, #diameter_packet{header = #diameter_header{application_id = Id}} = Pkt, recv_request(find_recv_app(Id, SApps), {SvcName, OH, OR}, TPid, Apps, Mask, Caps, Pkt). %% find_recv_app/2 %% No one should be sending the relay identifier. find_recv_app(?APP_ID_RELAY, _) -> false; %% With any other id we either support it locally or as a relay. find_recv_app(Id, SApps) -> keyfind([Id, ?APP_ID_RELAY], 1, SApps). %% keyfind/3 keyfind([], _, _) -> false; keyfind([Key | Rest], Pos, L) -> case lists:keyfind(Key, Pos, L) of false -> keyfind(Rest, Pos, L); T -> T end. %% recv_request/7 recv_request({Id, Alias}, T, TPid, Apps, Mask, Caps, Pkt) -> #diameter_app{dictionary = Dict} = A = find_app(Alias, Apps), recv_request(T, {TPid, Caps}, A, Mask, diameter_codec:decode(Id, Dict, Pkt)); %% Note that the decode is different depending on whether or not Id is %% ?APP_ID_RELAY. %% DIAMETER_APPLICATION_UNSUPPORTED 3007 %% A request was sent for an application that is not supported. recv_request(false, T, TPid, _, _, _, Pkt) -> As = collect_avps(Pkt), protocol_error(3007, T, TPid, Pkt#diameter_packet{avps = As}). collect_avps(Pkt) -> case diameter_codec:collect_avps(Pkt) of {_Bs, As} -> As; As -> As end. %% recv_request/5 %% Wrong number of bits somewhere in the message: reply. %% %% DIAMETER_INVALID_AVP_BITS 3009 %% A request was received that included an AVP whose flag bits are %% set to an unrecognized value, or that is inconsistent with the %% AVP's definition. %% recv_request(T, {TPid, _}, _, _, #diameter_packet{errors = [Bs | _]} = Pkt) when is_bitstring(Bs) -> protocol_error(3009, T, TPid, Pkt); %% Either we support this application but don't recognize the command %% or we're a relay and the command isn't proxiable. %% %% DIAMETER_COMMAND_UNSUPPORTED 3001 %% The Request contained a Command-Code that the receiver did not %% recognize or support. This MUST be used when a Diameter node %% receives an experimental command that it does not understand. %% recv_request(T, {TPid, _}, #diameter_app{id = Id}, _, #diameter_packet{header = #diameter_header{is_proxiable = P}, msg = M} = Pkt) when ?APP_ID_RELAY /= Id, undefined == M; ?APP_ID_RELAY == Id, not P -> protocol_error(3001, T, TPid, Pkt); %% Error bit was set on a request. %% %% DIAMETER_INVALID_HDR_BITS 3008 %% A request was received whose bits in the Diameter header were %% either set to an invalid combination, or to a value that is %% inconsistent with the command code's definition. %% recv_request(T, {TPid, _}, _, _, #diameter_packet{header = #diameter_header{is_error = true}} = Pkt) -> protocol_error(3008, T, TPid, Pkt); %% A message in a locally supported application or a proxiable message %% in the relay application. Don't distinguish between the two since %% each application has its own callback config. That is, the user can %% easily distinguish between the two cases. recv_request(T, TC, App, Mask, Pkt) -> request_cb(T, TC, App, Mask, examine(Pkt)). %% Note that there may still be errors but these aren't protocol %% (3xxx) errors that lead to an answer-message. request_cb({SvcName, _OH, _OR} = T, TC, App, Mask, Pkt) -> request_cb(cb(App, handle_request, [Pkt, SvcName, TC]), App, Mask, T, TC, [], Pkt). %% examine/1 %% %% Look for errors in a decoded message. Length errors result in %% decode failure in diameter_codec. examine(#diameter_packet{header = #diameter_header{version = ?DIAMETER_VERSION}} = Pkt) -> Pkt; %% DIAMETER_UNSUPPORTED_VERSION 5011 %% This error is returned when a request was received, whose version %% number is unsupported. examine(#diameter_packet{errors = Es} = Pkt) -> Pkt#diameter_packet{errors = [5011 | Es]}. %% It's odd/unfortunate that this isn't a protocol error. %% request_cb/7 %% A reply may be an answer-message, constructed either here or by %% the handle_request callback. The header from the incoming request %% is passed into the encode so that it can retrieve the relevant %% command code in this case. It will also then ignore Dict and use %% the base encoder. request_cb({reply, Ans}, #diameter_app{dictionary = Dict}, _, _, {TPid, _}, Fs, Pkt) -> reply(Ans, Dict, TPid, Fs, Pkt); %% An 3xxx result code, for which the E-bit is set in the header. request_cb({protocol_error, RC}, _, _, T, {TPid, _}, Fs, Pkt) when 3000 =< RC, RC < 4000 -> protocol_error(RC, T, TPid, Fs, Pkt); %% RFC 3588 says we must reply 3001 to anything unrecognized or %% unsupported. 'noreply' is undocumented (and inappropriately named) %% backwards compatibility for this, protocol_error the documented %% alternative. request_cb(noreply, _, _, T, {TPid, _}, Fs, Pkt) -> protocol_error(3001, T, TPid, Fs, Pkt); %% Relay a request to another peer. This is equivalent to doing an %% explicit call/4 with the message in question except that (1) a loop %% will be detected by examining Route-Record AVP's, (3) a %% Route-Record AVP will be added to the outgoing request and (3) the %% End-to-End Identifier will default to that in the %% #diameter_header{} without the need for an end_to_end_identifier %% option. %% %% relay and proxy are similar in that they require the same handling %% with respect to Route-Record and End-to-End identifier. The %% difference is that a proxy advertises specific applications, while %% a relay advertises the relay application. If a callback doesn't %% want to distinguish between the cases in the callback return value %% then 'resend' is a neutral alternative. %% request_cb({A, Opts}, #diameter_app{id = Id} = App, Mask, T, TC, Fs, Pkt) when A == relay, Id == ?APP_ID_RELAY; A == proxy, Id /= ?APP_ID_RELAY; A == resend -> resend(Opts, App, Mask, T, TC, Fs, Pkt); request_cb(discard, _, _, _, _, _, _) -> ok; request_cb({eval_packet, RC, F}, App, Mask, T, TC, Fs, Pkt) -> request_cb(RC, App, Mask, T, TC, [F|Fs], Pkt); request_cb({eval, RC, F}, App, Mask, T, TC, Fs, Pkt) -> request_cb(RC, App, Mask, T, TC, Fs, Pkt), diameter_lib:eval(F). %% protocol_error/5 protocol_error(RC, {_, OH, OR}, TPid, Fs, Pkt) -> #diameter_packet{avps = Avps, errors = Es} = Pkt, ?LOG({error, RC}, Pkt), reply(answer_message({OH, OR, RC}, Avps), ?BASE, TPid, Fs, Pkt#diameter_packet{errors = [RC | Es]}). %% Note that reply/5 may set the result code once more. It's set in %% answer_message/2 in case reply/5 doesn't. %% protocol_error/4 protocol_error(RC, T, TPid, Pkt) -> protocol_error(RC, T, TPid, [], Pkt). %% resend/7 %% %% Resend a message as a relay or proxy agent. resend(Opts, #diameter_app{} = App, Mask, {_SvcName, OH, _OR} = T, {_TPid, _Caps} = TC, Fs, #diameter_packet{avps = Avps} = Pkt) -> {Code, _Flags, Vid} = ?BASE:avp_header('Route-Record'), resend(is_loop(Code, Vid, OH, Avps), Opts, App, Mask, T, TC, Fs, Pkt). %% DIAMETER_LOOP_DETECTED 3005 %% An agent detected a loop while trying to get the message to the %% intended recipient. The message MAY be sent to an alternate peer, %% if one is available, but the peer reporting the error has %% identified a configuration problem. resend(true, _, _, _, T, {TPid, _}, Fs, Pkt) -> %% Route-Record loop protocol_error(3005, T, TPid, Fs, Pkt); %% 6.1.8. Relaying and Proxying Requests %% %% A relay or proxy agent MUST append a Route-Record AVP to all requests %% forwarded. The AVP contains the identity of the peer the request was %% received from. resend(false, Opts, App, Mask, {SvcName, _, _} = T, {TPid, #diameter_caps{origin_host = {_, OH}}}, Fs, #diameter_packet{header = Hdr0, avps = Avps} = Pkt) -> Route = #diameter_avp{data = {?BASE, 'Route-Record', OH}}, Seq = diameter_session:sequence(Mask), Hdr = Hdr0#diameter_header{hop_by_hop_id = Seq}, Msg = [Hdr, Route | Avps], resend(call(SvcName, App, Msg, Opts), T, TPid, Fs, Pkt). %% The incoming request is relayed with the addition of a %% Route-Record. Note the requirement on the return from call/4 below, %% which places a requirement on the value returned by the %% handle_answer callback of the application module in question. %% %% Note that there's nothing stopping the request from being relayed %% back to the sender. A pick_peer callback may want to avoid this but %% a smart peer might recognize the potential loop and choose another %% route. A less smart one will probably just relay the request back %% again and force us to detect the loop. A pick_peer that wants to %% avoid this can specify filter to avoid the possibility. %% Eg. {neg, {host, OH} where #diameter_caps{origin_host = {OH, _}}. %% %% RFC 6.3 says that a relay agent does not modify Origin-Host but %% says nothing about a proxy. Assume it should behave the same way. %% resend/4 %% %% Relay a reply to a relayed request. %% Answer from the peer: reset the hop by hop identifier and send. resend(#diameter_packet{bin = B} = Pkt, _, TPid, Fs, #diameter_packet{header = #diameter_header{hop_by_hop_id = Id}, transport_data = TD}) -> P = Pkt#diameter_packet{bin = diameter_codec:hop_by_hop_id(Id, B), transport_data = TD}, eval_packet(P, Fs), send(TPid, P); %% TODO: counters %% Or not: DIAMETER_UNABLE_TO_DELIVER. resend(_, T, TPid, Fs, Pkt) -> protocol_error(3002, T, TPid, Fs, Pkt). %% is_loop/4 %% %% Is there a Route-Record AVP with our Origin-Host? is_loop(Code, Vid, Bin, [#diameter_avp{code = Code, vendor_id = Vid, data = Bin} | _]) -> true; is_loop(_, _, _, []) -> false; is_loop(Code, Vid, OH, [_ | Avps]) when is_binary(OH) -> is_loop(Code, Vid, OH, Avps); is_loop(Code, Vid, OH, Avps) -> is_loop(Code, Vid, ?BASE:avp(encode, OH, 'Route-Record'), Avps). %% reply/5 %% %% Send a locally originating reply. %% Skip the setting of Result-Code and Failed-AVP's below. This is %% currently undocumented. reply([Msg], Dict, TPid, Fs, Pkt) when is_list(Msg); is_tuple(Msg) -> reply(Msg, Dict, TPid, Fs, Pkt#diameter_packet{errors = []}); %% No errors or a diameter_header/avp list. reply(Msg, Dict, TPid, Fs, #diameter_packet{errors = Es} = ReqPkt) when [] == Es; is_record(hd(Msg), diameter_header) -> Pkt = diameter_codec:encode(Dict, make_answer_packet(Msg, ReqPkt)), eval_packet(Pkt, Fs), incr(send, Pkt, Dict, TPid), %% count result codes in sent answers send(TPid, Pkt); %% Or not: set Result-Code and Failed-AVP AVP's. reply(Msg, Dict, TPid, Fs, #diameter_packet{errors = [H|_] = Es} = Pkt) -> reply(rc(Msg, rc(H), [A || {_,A} <- Es], Dict), Dict, TPid, Fs, Pkt#diameter_packet{errors = []}). eval_packet(Pkt, Fs) -> lists:foreach(fun(F) -> diameter_lib:eval([F,Pkt]) end, Fs). %% make_answer_packet/2 %% A reply message clears the R and T flags and retains the P flag. %% The E flag will be set at encode. 6.2 of 3588 requires the same P %% flag on an answer as on the request. A #diameter_packet{} returned %% from a handle_request callback can circumvent this by setting its %% own header values. make_answer_packet(#diameter_packet{header = Hdr, msg = Msg, transport_data = TD}, #diameter_packet{header = ReqHdr}) -> Hdr0 = ReqHdr#diameter_header{version = ?DIAMETER_VERSION, is_request = false, is_error = undefined, is_retransmitted = false}, #diameter_packet{header = fold_record(Hdr0, Hdr), msg = Msg, transport_data = TD}; %% Binaries and header/avp lists are sent as-is. make_answer_packet(Bin, #diameter_packet{transport_data = TD}) when is_binary(Bin) -> #diameter_packet{bin = Bin, transport_data = TD}; make_answer_packet([#diameter_header{} | _] = Msg, #diameter_packet{transport_data = TD}) -> #diameter_packet{msg = Msg, transport_data = TD}; %% Otherwise, preserve transport_data. make_answer_packet(Msg, #diameter_packet{transport_data = TD} = Pkt) -> make_answer_packet(#diameter_packet{msg = Msg, transport_data = TD}, Pkt). %% rc/1 rc({RC, _}) -> RC; rc(RC) -> RC. %% rc/4 rc(#diameter_packet{msg = Rec} = Pkt, RC, Failed, Dict) -> Pkt#diameter_packet{msg = rc(Rec, RC, Failed, Dict)}; rc(Rec, RC, Failed, Dict) when is_integer(RC) -> set(Rec, lists:append([rc(Rec, {'Result-Code', RC}, Dict), failed_avp(Rec, Failed, Dict)]), Dict). %% Reply as name and tuple list ... set([_|_] = Ans, Avps, _) -> Ans ++ Avps; %% Values nearer tail take precedence. %% ... or record. set(Rec, Avps, Dict) -> Dict:'#set-'(Avps, Rec). %% rc/3 %% %% Turn the result code into a list if its optional and only set it if %% the arity is 1 or {0,1}. In other cases (which probably shouldn't %% exist in practise) we can't know what's appropriate. rc([MsgName | _], {'Result-Code' = K, RC} = T, Dict) -> case Dict:avp_arity(MsgName, 'Result-Code') of 1 -> [T]; {0,1} -> [{K, [RC]}]; _ -> [] end; rc(Rec, T, Dict) -> rc([Dict:rec2msg(element(1, Rec))], T, Dict). %% failed_avp/3 failed_avp(_, [] = No, _) -> No; failed_avp(Rec, Failed, Dict) -> [fa(Rec, [{'AVP', Failed}], Dict)]. %% Reply as name and tuple list ... fa([MsgName | Values], FailedAvp, Dict) -> R = Dict:msg2rec(MsgName), try Dict:'#info-'(R, {index, 'Failed-AVP'}), {'Failed-AVP', [FailedAvp]} catch error: _ -> Avps = proplists:get_value('AVP', Values, []), A = #diameter_avp{name = 'Failed-AVP', value = FailedAvp}, {'AVP', [A|Avps]} end; %% ... or record. fa(Rec, FailedAvp, Dict) -> try {'Failed-AVP', [FailedAvp]} catch error: _ -> Avps = Dict:'get-'('AVP', Rec), A = #diameter_avp{name = 'Failed-AVP', value = FailedAvp}, {'AVP', [A|Avps]} end. %% 3. Diameter Header %% %% E(rror) - If set, the message contains a protocol error, %% and the message will not conform to the ABNF %% described for this command. Messages with the 'E' %% bit set are commonly referred to as error %% messages. This bit MUST NOT be set in request %% messages. See Section 7.2. %% 3.2. Command Code ABNF specification %% %% e-bit = ", ERR" %% ; If present, the 'E' bit in the Command %% ; Flags is set, indicating that the answer %% ; message contains a Result-Code AVP in %% ; the "protocol error" class. %% 7.1.3. Protocol Errors %% %% Errors that fall within the Protocol Error category SHOULD be treated %% on a per-hop basis, and Diameter proxies MAY attempt to correct the %% error, if it is possible. Note that these and only these errors MUST %% only be used in answer messages whose 'E' bit is set. %% Thus, only construct answers to protocol errors. Other errors %% require an message-specific answer and must be handled by the %% application. %% 6.2. Diameter Answer Processing %% %% When a request is locally processed, the following procedures MUST be %% applied to create the associated answer, in addition to any %% additional procedures that MAY be discussed in the Diameter %% application defining the command: %% %% - The same Hop-by-Hop identifier in the request is used in the %% answer. %% %% - The local host's identity is encoded in the Origin-Host AVP. %% %% - The Destination-Host and Destination-Realm AVPs MUST NOT be %% present in the answer message. %% %% - The Result-Code AVP is added with its value indicating success or %% failure. %% %% - If the Session-Id is present in the request, it MUST be included %% in the answer. %% %% - Any Proxy-Info AVPs in the request MUST be added to the answer %% message, in the same order they were present in the request. %% %% - The 'P' bit is set to the same value as the one in the request. %% %% - The same End-to-End identifier in the request is used in the %% answer. %% %% Note that the error messages (see Section 7.3) are also subjected to %% the above processing rules. %% 7.3. Error-Message AVP %% %% The Error-Message AVP (AVP Code 281) is of type UTF8String. It MAY %% accompany a Result-Code AVP as a human readable error message. The %% Error-Message AVP is not intended to be useful in real-time, and %% SHOULD NOT be expected to be parsed by network entities. %% answer_message/2 answer_message({OH, OR, RC}, Avps) -> {Code, _, Vid} = ?BASE:avp_header('Session-Id'), ['answer-message', {'Origin-Host', OH}, {'Origin-Realm', OR}, {'Result-Code', RC} | session_id(Code, Vid, Avps)]. session_id(Code, Vid, Avps) when is_list(Avps) -> try {value, #diameter_avp{data = D}} = find_avp(Code, Vid, Avps), [{'Session-Id', [?BASE:avp(decode, D, 'Session-Id')]}] catch error: _ -> [] end. %% find_avp/3 find_avp(Code, Vid, Avps) when is_integer(Code), (undefined == Vid orelse is_integer(Vid)) -> find(fun(A) -> is_avp(Code, Vid, A) end, Avps). %% The final argument here could be a list of AVP's, depending on the case, %% but we're only searching at the top level. is_avp(Code, Vid, #diameter_avp{code = Code, vendor_id = Vid}) -> true; is_avp(_, _, _) -> false. find(_, []) -> false; find(Pred, [H|T]) -> case Pred(H) of true -> {value, H}; false -> find(Pred, T) end. %% 7. Error Handling %% %% There are certain Result-Code AVP application errors that require %% additional AVPs to be present in the answer. In these cases, the %% Diameter node that sets the Result-Code AVP to indicate the error %% MUST add the AVPs. Examples are: %% %% - An unrecognized AVP is received with the 'M' bit (Mandatory bit) %% set, causes an answer to be sent with the Result-Code AVP set to %% DIAMETER_AVP_UNSUPPORTED, and the Failed-AVP AVP containing the %% offending AVP. %% %% - An AVP that is received with an unrecognized value causes an %% answer to be returned with the Result-Code AVP set to %% DIAMETER_INVALID_AVP_VALUE, with the Failed-AVP AVP containing the %% AVP causing the error. %% %% - A command is received with an AVP that is omitted, yet is %% mandatory according to the command's ABNF. The receiver issues an %% answer with the Result-Code set to DIAMETER_MISSING_AVP, and %% creates an AVP with the AVP Code and other fields set as expected %% in the missing AVP. The created AVP is then added to the Failed- %% AVP AVP. %% %% The Result-Code AVP describes the error that the Diameter node %% encountered in its processing. In case there are multiple errors, %% the Diameter node MUST report only the first error it encountered %% (detected possibly in some implementation dependent order). The %% specific errors that can be described by this AVP are described in %% the following section. %% 7.5. Failed-AVP AVP %% %% The Failed-AVP AVP (AVP Code 279) is of type Grouped and provides %% debugging information in cases where a request is rejected or not %% fully processed due to erroneous information in a specific AVP. The %% value of the Result-Code AVP will provide information on the reason %% for the Failed-AVP AVP. %% %% The possible reasons for this AVP are the presence of an improperly %% constructed AVP, an unsupported or unrecognized AVP, an invalid AVP %% value, the omission of a required AVP, the presence of an explicitly %% excluded AVP (see tables in Section 10), or the presence of two or %% more occurrences of an AVP which is restricted to 0, 1, or 0-1 %% occurrences. %% %% A Diameter message MAY contain one Failed-AVP AVP, containing the %% entire AVP that could not be processed successfully. If the failure %% reason is omission of a required AVP, an AVP with the missing AVP %% code, the missing vendor id, and a zero filled payload of the minimum %% required length for the omitted AVP will be added. %%% --------------------------------------------------------------------------- %%% # handle_answer/3 %%% --------------------------------------------------------------------------- %% Process an answer message in call-specific process. handle_answer(SvcName, _, {error, Req, Reason}) -> handle_error(Req, Reason, SvcName); handle_answer(SvcName, AnswerErrors, {answer, #request{dictionary = Dict} = Req, Pkt}) -> answer(examine(diameter_codec:decode(Dict, Pkt)), SvcName, AnswerErrors, Req). %% We don't really need to do a full decode if we're a relay and will %% just resend with a new hop by hop identifier, but might a proxy %% want to examine the answer? answer(Pkt, SvcName, AE, #request{transport = TPid, dictionary = Dict} = Req) -> try incr(recv, Pkt, Dict, TPid) of _ -> a(Pkt, SvcName, AE, Req) catch exit: {invalid_error_bit, _} = E -> a(Pkt#diameter_packet{errors = [E]}, SvcName, AE, Req) end. a(#diameter_packet{errors = Es} = Pkt, SvcName, AE, #request{transport = TPid, caps = Caps, packet = P} = Req) when [] == Es; callback == AE -> cb(Req, handle_answer, [Pkt, msg(P), SvcName, {TPid, Caps}]); a(Pkt, SvcName, report, Req) -> x(errors, handle_answer, [SvcName, Req, Pkt]); a(Pkt, SvcName, discard, Req) -> x({errors, handle_answer, [SvcName, Req, Pkt]}). %% Note that we don't check that the application id in the answer's %% header is what we expect. (TODO: Does the rfc says anything about %% this?) %% incr/4 %% %% Increment a stats counter for an incoming or outgoing message. %% TODO: fix incr(_, #diameter_packet{msg = undefined}, _, _) -> ok; incr(recv = D, #diameter_packet{header = H, errors = [_|_]}, _, TPid) -> incr(TPid, {diameter_codec:msg_id(H), D, error}); incr(Dir, Pkt, Dict, TPid) -> #diameter_packet{header = #diameter_header{is_error = E} = Hdr, msg = Rec} = Pkt, RC = int(get_avp_value(Dict, 'Result-Code', Rec)), PE = is_protocol_error(RC), %% Check that the E bit is set only for 3xxx result codes. (not (E orelse PE)) orelse (E andalso PE) orelse x({invalid_error_bit, RC}, answer, [Dir, Pkt]), irc(TPid, Hdr, Dir, rc_counter(Dict, Rec, RC)). irc(_, _, _, undefined) -> false; irc(TPid, Hdr, Dir, Ctr) -> incr(TPid, {diameter_codec:msg_id(Hdr), Dir, Ctr}). %% incr/2 incr(TPid, Counter) -> diameter_stats:incr(Counter, TPid, 1). %% error_counter/2 %% RFC 3588, 7.6: %% %% All Diameter answer messages defined in vendor-specific %% applications MUST include either one Result-Code AVP or one %% Experimental-Result AVP. %% %% Maintain statistics assuming one or the other, not both, which is %% surely the intent of the RFC. rc_counter(Dict, Rec, undefined) -> er(get_avp_value(Dict, 'Experimental-Result', Rec)); rc_counter(_, _, RC) -> {'Result-Code', RC}. %% Outgoing answers may be in any of the forms messages can be sent %% in. Incoming messages will be records. We're assuming here that the %% arity of the result code AVP's is 0 or 1. er([{_,_,N} = T | _]) when is_integer(N) -> T; er({_,_,N} = T) when is_integer(N) -> T; er(_) -> undefined. %% Extract the first good looking integer. There's no guarantee %% that what we're looking for has arity 1. int([N|_]) when is_integer(N) -> N; int(N) when is_integer(N) -> N; int(_) -> undefined. is_protocol_error(RC) -> 3000 =< RC andalso RC < 4000. -spec x(any(), atom(), list()) -> no_return(). %% Warn and exit request process on errors in an incoming answer. x(Reason, F, A) -> diameter_lib:warning_report(Reason, {?MODULE, F, A}), x(Reason). x(T) -> exit(T). %%% --------------------------------------------------------------------------- %%% # failover/[23] %%% --------------------------------------------------------------------------- %% Failover as a consequence of request_peer_down/2. failover({_, #request{handler = Pid} = Req, TRef}, S) -> Pid ! {failover, TRef, rt(Req, S)}. %% Failover as a consequence of store_request/4. failover(TRef, Seqs, S) when is_reference(TRef) -> case lookup_request(Seqs, TRef) of #request{} = Req -> failover({Seqs, Req, TRef}, S); false -> ok end. %% prepare_request returned a binary ... rt(#request{packet = #diameter_packet{msg = undefined}}, _) -> false; %% TODO: Not what we should do. %% ... or not. rt(#request{packet = #diameter_packet{msg = Msg}, dictionary = Dict} = Req, S) -> find_transport(get_destination(Dict, Msg), Req, S). %%% --------------------------------------------------------------------------- %%% # report_status/5 %%% --------------------------------------------------------------------------- report_status(Status, #peer{ref = Ref, conn = TPid, type = Type, options = Opts}, #conn{apps = [_|_] = As, caps = Caps}, #state{service_name = SvcName} = S, Extra) -> share_peer(Status, Caps, As, TPid, S), Info = [Status, Ref, {TPid, Caps}, {type(Type), Opts} | Extra], send_event(SvcName, list_to_tuple(Info)). %% send_event/2 send_event(SvcName, Info) -> send_event(#diameter_event{service = SvcName, info = Info}). send_event(#diameter_event{service = SvcName} = E) -> lists:foreach(fun({_, Pid}) -> Pid ! E end, subscriptions(SvcName)). %%% --------------------------------------------------------------------------- %%% # share_peer/5 %%% --------------------------------------------------------------------------- share_peer(up, Caps, Aliases, TPid, #state{options = [_, {_, true} | _], service_name = Svc}) -> diameter_peer:notify(Svc, {peer, TPid, Aliases, Caps}); share_peer(_, _, _, _, _) -> ok. %%% --------------------------------------------------------------------------- %%% # share_peers/2 %%% --------------------------------------------------------------------------- share_peers(Pid, #state{options = [_, {_, true} | _], local_peers = PDict}) -> ?Dict:fold(fun(A,Ps,ok) -> sp(Pid, A, Ps), ok end, ok, PDict); share_peers(_, _) -> ok. sp(Pid, Alias, Peers) -> lists:foreach(fun({P,C}) -> Pid ! {peer, P, [Alias], C} end, Peers). %%% --------------------------------------------------------------------------- %%% # remote_peer_up/4 %%% --------------------------------------------------------------------------- remote_peer_up(Pid, Aliases, Caps, #state{options = [_, _, {_, true} | _], service = Svc, shared_peers = PDict}) -> #diameter_service{applications = Apps} = Svc, Key = #diameter_app.alias, As = lists:filter(fun(A) -> lists:keymember(A, Key, Apps) end, Aliases), rpu(Pid, Caps, PDict, As); remote_peer_up(_, _, _, #state{options = [_, _, {_, false} | _]}) -> ok. rpu(_, _, PDict, []) -> PDict; rpu(Pid, Caps, PDict, Aliases) -> erlang:monitor(process, Pid), T = {Pid, Caps}, lists:foreach(fun(A) -> ?Dict:append(A, T, PDict) end, Aliases). %%% --------------------------------------------------------------------------- %%% # remote_peer_down/2 %%% --------------------------------------------------------------------------- remote_peer_down(Pid, #state{options = [_, _, {_, true} | _], shared_peers = PDict}) -> lists:foreach(fun(A) -> rpd(Pid, A, PDict) end, ?Dict:fetch_keys(PDict)). rpd(Pid, Alias, PDict) -> ?Dict:update(Alias, fun(Ps) -> lists:keydelete(Pid, 1, Ps) end, PDict). %%% --------------------------------------------------------------------------- %%% find_transport/[34] %%% %%% Output: {TransportPid, #diameter_caps{}, #diameter_app{}} %%% | false %%% | {error, Reason} %%% --------------------------------------------------------------------------- %% Initial call, from an arbitrary process. find_transport({alias, Alias}, Msg, Opts, #state{service = Svc} = S) -> #diameter_service{applications = Apps} = Svc, ft(find_send_app(Alias, Apps), Msg, Opts, S); %% Relay or proxy send. find_transport(#diameter_app{} = App, Msg, Opts, S) -> ft(App, Msg, Opts, S). ft(#diameter_app{module = Mod, dictionary = Dict} = App, Msg, Opts, S) -> #options{filter = Filter, extra = Xtra} = Opts, pick_peer(App#diameter_app{module = Mod ++ Xtra}, get_destination(Dict, Msg), Filter, S); ft(false = No, _, _, _) -> No. %% This can't be used if we're a relay and sending a message %% in an application not known locally. (TODO) find_send_app(Alias, Apps) -> case lists:keyfind(Alias, #diameter_app.alias, Apps) of #diameter_app{id = ?APP_ID_RELAY} -> false; T -> T end. %% Retransmission, in the service process. find_transport([_,_] = RH, Req, #state{service = #diameter_service{pid = Pid, applications = Apps}} = S) when self() == Pid -> #request{app = Alias, filter = Filter, module = ModX} = Req, #diameter_app{} = App = lists:keyfind(Alias, #diameter_app.alias, Apps), pick_peer(App#diameter_app{module = ModX}, RH, Filter, S). %% get_destination/2 get_destination(Dict, Msg) -> [str(get_avp_value(Dict, 'Destination-Realm', Msg)), str(get_avp_value(Dict, 'Destination-Host', Msg))]. %% This is not entirely correct. The avp could have an arity 1, in %% which case an empty list is a DiameterIdentity of length 0 rather %% than the list of no values we treat it as by mapping to undefined. %% This behaviour is documented. str([]) -> undefined; str(T) -> T. %% get_avp_value/3 %% %% Find an AVP in a message of one of three forms: %% %% - a message record (as generated from a .dia spec) or %% - a list of an atom message name followed by 2-tuple, avp name/value pairs. %% - a list of a #diameter_header{} followed by #diameter_avp{} records, %% %% In the first two forms a dictionary module is used at encode to %% identify the type of the AVP and its arity in the message in %% question. The third form allows messages to be sent as is, without %% a dictionary, which is needed in the case of relay agents, for one. %% Messages will be header/avps list as a relay and the only AVP's we %% look for are in the common dictionary. This is required since the %% relay dictionary doesn't inherit the common dictionary (which maybe %% it should). get_avp_value(?RELAY, Name, Msg) -> get_avp_value(?BASE, Name, Msg); %% Message sent as a header/avps list, probably a relay case but not %% necessarily. get_avp_value(Dict, Name, [#diameter_header{} | Avps]) -> try {Code, _, VId} = Dict:avp_header(Name), [A|_] = lists:dropwhile(fun(#diameter_avp{code = C, vendor_id = V}) -> C /= Code orelse V /= VId end, Avps), avp_decode(Dict, Name, A) catch error: _ -> undefined end; %% Outgoing message as a name/values list. get_avp_value(_, Name, [_MsgName | Avps]) -> case lists:keyfind(Name, 1, Avps) of {_, V} -> V; _ -> undefined end; %% Record might be an answer message in the common dictionary. get_avp_value(Dict, Name, Rec) when Dict /= ?BASE, element(1, Rec) == 'diameter_base_answer-message' -> get_avp_value(?BASE, Name, Rec); %% Message is typically a record but not necessarily: diameter:call/4 %% can be passed an arbitrary term. get_avp_value(Dict, Name, Rec) -> try Dict:'#get-'(Name, Rec) catch error:_ -> undefined end. avp_decode(Dict, Name, #diameter_avp{value = undefined, data = Bin}) -> Dict:avp(decode, Bin, Name); avp_decode(_, _, #diameter_avp{value = V}) -> V. %%% --------------------------------------------------------------------------- %%% # pick_peer(App, [DestRealm, DestHost], Filter, #state{}) %%% %%% Output: {TransportPid, #diameter_caps{}, App} %%% | false %%% | {error, Reason} %%% --------------------------------------------------------------------------- %% Find transports to a given realm/host. pick_peer(#diameter_app{alias = Alias} = App, [_,_] = RH, Filter, #state{local_peers = L, shared_peers = S, service_name = SvcName, service = #diameter_service{pid = Pid}}) -> pick_peer(peers(Alias, RH, Filter, L), peers(Alias, RH, Filter, S), Pid, SvcName, App). %% pick_peer/5 pick_peer([], [], _, _, _) -> false; %% App state is mutable but we're not in the service process: go there. pick_peer(Local, Remote, Pid, _SvcName, #diameter_app{mutable = true} = App) when self() /= Pid -> call_service(Pid, {pick_peer, Local, Remote, App}); %% App state isn't mutable or it is and we're in the service process: %% do the deed. pick_peer(Local, Remote, _Pid, SvcName, #diameter_app{module = ModX, alias = Alias, init_state = S, mutable = M} = App) -> MFA = {ModX, pick_peer, [Local, Remote, SvcName]}, try state_cb(App, MFA) of {ok, {TPid, #diameter_caps{} = Caps}} when is_pid(TPid) -> {TPid, Caps, App}; {{TPid, #diameter_caps{} = Caps}, ModS} when is_pid(TPid), M -> mod_state(Alias, ModS), {TPid, Caps, App}; {false = No, ModS} when M -> mod_state(Alias, ModS), No; {ok, false = No} -> No; false = No -> No; {{TPid, #diameter_caps{} = Caps}, S} when is_pid(TPid) -> {TPid, Caps, App}; %% Accept returned state in the immutable {false = No, S} -> %% case as long it isn't changed. No; T -> diameter_lib:error_report({invalid, T, App}, MFA) catch E: Reason -> diameter_lib:error_report({failure, {E, Reason, ?STACK}}, MFA) end. %% peers/4 peers(Alias, RH, Filter, Peers) -> case ?Dict:find(Alias, Peers) of {ok, L} -> ps(L, RH, Filter, {[],[]}); error -> [] end. %% Place a peer whose Destination-Host/Realm matches those of the %% request at the front of the result list. Could add some sort of %% 'sort' option to allow more control. ps([], _, _, {Ys, Ns}) -> lists:reverse(Ys, Ns); ps([{_TPid, #diameter_caps{} = Caps} = TC | Rest], RH, Filter, Acc) -> ps(Rest, RH, Filter, pacc(caps_filter(Caps, RH, Filter), caps_filter(Caps, RH, {all, [host, realm]}), TC, Acc)). pacc(true, true, Peer, {Ts, Fs}) -> {[Peer|Ts], Fs}; pacc(true, false, Peer, {Ts, Fs}) -> {Ts, [Peer|Fs]}; pacc(_, _, _, Acc) -> Acc. %% caps_filter/3 caps_filter(C, RH, {neg, F}) -> not caps_filter(C, RH, F); caps_filter(C, RH, {all, L}) when is_list(L) -> lists:all(fun(F) -> caps_filter(C, RH, F) end, L); caps_filter(C, RH, {any, L}) when is_list(L) -> lists:any(fun(F) -> caps_filter(C, RH, F) end, L); caps_filter(#diameter_caps{origin_host = {_,OH}}, [_,DH], host) -> eq(undefined, DH, OH); caps_filter(#diameter_caps{origin_realm = {_,OR}}, [DR,_], realm) -> eq(undefined, DR, OR); caps_filter(C, _, Filter) -> caps_filter(C, Filter). %% caps_filter/2 caps_filter(_, none) -> true; caps_filter(#diameter_caps{origin_host = {_,OH}}, {host, H}) -> eq(any, H, OH); caps_filter(#diameter_caps{origin_realm = {_,OR}}, {realm, R}) -> eq(any, R, OR); %% Anything else is expected to be an eval filter. Filter failure is %% documented as being equivalent to a non-matching filter. caps_filter(C, T) -> try {eval, F} = T, diameter_lib:eval([F,C]) catch _:_ -> false end. eq(Any, Id, PeerId) -> Any == Id orelse try iolist_to_binary(Id) == iolist_to_binary(PeerId) catch _:_ -> false end. %% OctetString() can be specified as an iolist() so test for string %% rather then term equality. %% transports/1 transports(#state{peerT = PeerT}) -> ets:select(PeerT, [{#peer{conn = '$1', _ = '_'}, [{'is_pid', '$1'}], ['$1']}]). %%% --------------------------------------------------------------------------- %%% # service_info/2 %%% --------------------------------------------------------------------------- %% The config passed to diameter:start_service/2. -define(CAP_INFO, ['Origin-Host', 'Origin-Realm', 'Vendor-Id', 'Product-Name', 'Origin-State-Id', 'Host-IP-Address', 'Supported-Vendor-Id', 'Auth-Application-Id', 'Inband-Security-Id', 'Acct-Application-Id', 'Vendor-Specific-Application-Id', 'Firmware-Revision']). %% The config returned by diameter:service_info(SvcName, all). -define(ALL_INFO, [capabilities, applications, transport, pending, options]). %% The rest. -define(OTHER_INFO, [connections, name, peers, statistics]). service_info(Item, S) when is_atom(Item) -> case tagged_info(Item, S) of {_, T} -> T; undefined = No -> No end; service_info(Items, S) -> tagged_info(Items, S). tagged_info(Item, S) when is_atom(Item) -> case complete(Item) of {value, I} -> {I, complete_info(I,S)}; false -> undefined end; tagged_info(TPid, #state{peerT = PT, connT = CT}) when is_pid(TPid) -> try [#conn{peer = Pid}] = ets:lookup(CT, TPid), [#peer{ref = Ref, type = Type, options = Opts}] = ets:lookup(PT, Pid), [{ref, Ref}, {type, Type}, {options, Opts}] catch error:_ -> [] end; tagged_info(Items, S) when is_list(Items) -> [T || I <- Items, T <- [tagged_info(I,S)], T /= undefined, T /= []]; tagged_info(_, _) -> undefined. complete_info(Item, #state{service = Svc} = S) -> case Item of name -> S#state.service_name; 'Origin-Host' -> (Svc#diameter_service.capabilities) #diameter_caps.origin_host; 'Origin-Realm' -> (Svc#diameter_service.capabilities) #diameter_caps.origin_realm; 'Vendor-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.vendor_id; 'Product-Name' -> (Svc#diameter_service.capabilities) #diameter_caps.product_name; 'Origin-State-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.origin_state_id; 'Host-IP-Address' -> (Svc#diameter_service.capabilities) #diameter_caps.host_ip_address; 'Supported-Vendor-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.supported_vendor_id; 'Auth-Application-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.auth_application_id; 'Inband-Security-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.inband_security_id; 'Acct-Application-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.acct_application_id; 'Vendor-Specific-Application-Id' -> (Svc#diameter_service.capabilities) #diameter_caps.vendor_specific_application_id; 'Firmware-Revision' -> (Svc#diameter_service.capabilities) #diameter_caps.firmware_revision; capabilities -> service_info(?CAP_INFO, S); applications -> info_apps(S); transport -> info_transport(S); options -> info_options(S); pending -> info_pending(S); keys -> ?ALL_INFO ++ ?CAP_INFO ++ ?OTHER_INFO; all -> service_info(?ALL_INFO, S); statistics -> info_stats(S); connections -> info_connections(S); peers -> info_peers(S) end. complete(I) when I == keys; I == all -> {value, I}; complete(Pre) -> P = atom_to_list(Pre), case [I || I <- ?ALL_INFO ++ ?CAP_INFO ++ ?OTHER_INFO, lists:prefix(P, atom_to_list(I))] of [I] -> {value, I}; _ -> false end. %% info_stats/1 info_stats(#state{peerT = PeerT}) -> MatchSpec = [{#peer{ref = '$1', conn = '$2', _ = '_'}, [{'is_pid', '$2'}], [['$1', '$2']]}], try ets:select(PeerT, MatchSpec) of L -> diameter_stats:read(lists:append(L)) catch error: badarg -> [] %% service has gone down end. %% info_transport/1 %% %% One entry per configured transport. Statistics for each entry are %% the accumulated values for the ref and associated peer pids. info_transport(S) -> PeerD = peer_dict(S, config_dict(S)), RefsD = dict:map(fun(_, Ls) -> [P || L <- Ls, {peer, {P,_}} <- L] end, PeerD), Refs = lists:append(dict:fold(fun(R, Ps, A) -> [[R|Ps] | A] end, [], RefsD)), Stats = diameter_stats:read(Refs), dict:fold(fun(R, Ls, A) -> Ps = dict:fetch(R, RefsD), [[{ref, R} | transport(Ls)] ++ [stats([R|Ps], Stats)] | A] end, [], PeerD). %% Only a config entry for a listening transport: use it. transport([[{type, listen}, _] = L]) -> L ++ [{accept, []}]; %% Only one config or peer entry for a connecting transport: use it. transport([[{type, connect} | _] = L]) -> L; %% Peer entries: discard config. Note that the peer entries have %% length at least 3. transport([[_,_] | L]) -> transport(L); %% Possibly many peer entries for a listening transport. Note that all %% have the same options by construction, which is not terribly space %% efficient. (TODO: all entries for the same Ref should share options.) transport([[{type, accept}, {options, Opts} | _] | _] = Ls) -> [{type, listen}, {options, Opts}, {accept, [lists:nthtail(2,L) || L <- Ls]}]. peer_dict(#state{peerT = PeerT, connT = ConnT}, Dict0) -> try ets:tab2list(PeerT) of L -> lists:foldl(fun(T,A) -> peer_acc(ConnT, A, T) end, Dict0, L) catch error: badarg -> Dict0 %% service has gone down end. peer_acc(ConnT, Acc, #peer{pid = Pid, type = Type, ref = Ref, options = Opts, op_state = {_, WS}, started = T, conn = TPid}) -> dict:append(Ref, [{type, Type}, {options, Opts}, {watchdog, {Pid, T, WS}} | info_conn(ConnT, TPid, WS /= ?WD_DOWN)], Acc). info_conn(ConnT, TPid, true) when is_pid(TPid) -> try ets:lookup(ConnT, TPid) of T -> info_conn(T) catch error: badarg -> [] %% service has gone down end; info_conn(_, _, _) -> []. %% The point of extracting the config here is so that 'transport' info %% has one entry for each transport ref, the peer table only %% containing entries that have a living watchdog. config_dict(#state{service_name = SvcName}) -> lists:foldl(fun config_acc/2, dict:new(), diameter_config:lookup(SvcName)). config_acc({Ref, T, Opts}, Dict) when T == listen; T == connect -> dict:store(Ref, [[{type, T}, {options, Opts}]], Dict); config_acc(_, Dict) -> Dict. info_conn([#conn{pid = Pid, apps = SApps, caps = Caps, started = T}]) -> [{peer, {Pid, T}}, {apps, SApps}, {caps, info_caps(Caps)} | try [{port, info_port(Pid)}] catch _:_ -> [] end]; info_conn([] = No) -> No. %% Extract information that the processes involved are expected to %% "publish" in their process dictionaries. Simple but backhanded. info_port(Pid) -> {_, PD} = process_info(Pid, dictionary), {_, T} = lists:keyfind({diameter_peer_fsm, start}, 1, PD), {TPid, {_Type, TMod, _Cfg}} = T, {_, TD} = process_info(TPid, dictionary), {_, Data} = lists:keyfind({TMod, info}, 1, TD), [{owner, TPid}, {module, TMod} | try TMod:info(Data) catch _:_ -> [] end]. %% Use the fields names from diameter_caps instead of %% diameter_base_CER to distinguish between the 2-tuple values %% compared to the single capabilities values. Note also that the %% returned list is tagged 'caps' rather than 'capabilities' to %% emphasize the difference. info_caps(#diameter_caps{} = C) -> lists:zip(record_info(fields, diameter_caps), tl(tuple_to_list(C))). info_apps(#state{service = #diameter_service{applications = Apps}}) -> lists:map(fun mk_app/1, Apps). mk_app(#diameter_app{} = A) -> lists:zip(record_info(fields, diameter_app), tl(tuple_to_list(A))). %% info_pending/1 %% %% One entry for each outgoing request whose answer is outstanding. info_pending(#state{} = S) -> MatchSpec = [{{'$1', #request{transport = '$2', from = '$3', app = '$4', _ = '_'}, '_'}, [?ORCOND([{'==', T, '$2'} || T <- transports(S)])], [{{'$1', [{{app, '$4'}}, {{transport, '$2'}}, {{from, '$3'}}]}}]}], try ets:select(?REQUEST_TABLE, MatchSpec) catch error: badarg -> [] %% service has gone down end. %% info_connections/1 %% %% One entry per transport connection. Statistics for each entry are %% for the peer pid only. info_connections(S) -> ConnL = conn_list(S), Stats = diameter_stats:read([P || L <- ConnL, {peer, {P,_}} <- L]), [L ++ [stats([P], Stats)] || L <- ConnL, {peer, {P,_}} <- L]. conn_list(S) -> lists:append(dict:fold(fun conn_acc/3, [], peer_dict(S, dict:new()))). conn_acc(Ref, Peers, Acc) -> [[[{ref, Ref} | L] || L <- Peers, lists:keymember(peer, 1, L)] | Acc]. stats(Refs, Stats) -> {statistics, dict:to_list(lists:foldl(fun(R,D) -> stats_acc(R, D, Stats) end, dict:new(), Refs))}. stats_acc(Ref, Dict, Stats) -> lists:foldl(fun({C,N}, D) -> dict:update_counter(C, N, D) end, Dict, proplists:get_value(Ref, Stats, [])). %% info_peers/1 %% %% One entry per peer Origin-Host. Statistics for each entry are %% accumulated values for all peer pids. info_peers(S) -> {PeerD, RefD} = lists:foldl(fun peer_acc/2, {dict:new(), dict:new()}, conn_list(S)), Refs = lists:append(dict:fold(fun(_, Rs, A) -> [Rs|A] end, [], RefD)), Stats = diameter_stats:read(Refs), dict:fold(fun(OH, Cs, A) -> Rs = dict:fetch(OH, RefD), [{OH, [{connections, Cs}, stats(Rs, Stats)]} | A] end, [], PeerD). peer_acc(Peer, {PeerD, RefD}) -> [{TPid, _}, [{origin_host, {_, OH}} | _]] = [proplists:get_value(K, Peer) || K <- [peer, caps]], {dict:append(OH, Peer, PeerD), dict:append(OH, TPid, RefD)}. %% info_options/1 info_options(S) -> S#state.options.