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Diffstat (limited to 'lib/diameter/src/app/diameter_peer_fsm.erl')
-rw-r--r-- | lib/diameter/src/app/diameter_peer_fsm.erl | 746 |
1 files changed, 0 insertions, 746 deletions
diff --git a/lib/diameter/src/app/diameter_peer_fsm.erl b/lib/diameter/src/app/diameter_peer_fsm.erl deleted file mode 100644 index 0252fb3809..0000000000 --- a/lib/diameter/src/app/diameter_peer_fsm.erl +++ /dev/null @@ -1,746 +0,0 @@ -%% -%% %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 implements (as a process) the RFC 3588 Peer State -%% Machine modulo the necessity of adapting the peer election to the -%% fact that we don't know the identity of a peer until we've -%% received a CER/CEA from it. -%% - --module(diameter_peer_fsm). --behaviour(gen_server). - -%% Interface towards diameter_watchdog. --export([start/3]). - -%% gen_server callbacks --export([init/1, - handle_call/3, - handle_cast/2, - handle_info/2, - terminate/2, - code_change/3]). - -%% diameter_peer_fsm_sup callback --export([start_link/1]). - -%% internal callbacks --export([match/1]). - --include_lib("diameter/include/diameter.hrl"). --include("diameter_internal.hrl"). --include("diameter_types.hrl"). --include("diameter_gen_base_rfc3588.hrl"). - --define(GOAWAY, ?'DIAMETER_BASE_DISCONNECT-CAUSE_DO_NOT_WANT_TO_TALK_TO_YOU'). --define(REBOOT, ?'DIAMETER_BASE_DISCONNECT-CAUSE_REBOOTING'). - --define(LOOP_TIMEOUT, 2000). - -%% RFC 3588: -%% -%% Timeout An application-defined timer has expired while waiting -%% for some event. -%% --define(EVENT_TIMEOUT, 10000). - -%% How long to wait for a DPA in response to DPR before simply -%% aborting. Used to distinguish between shutdown and not but there's -%% not really any need. Stopping a service will require a timeout if -%% the peer doesn't answer DPR so the value should be short-ish. --define(DPA_TIMEOUT, 1000). - --record(state, - {state = 'Wait-Conn-Ack' %% state of RFC 3588 Peer State Machine - :: 'Wait-Conn-Ack' | recv_CER | 'Wait-CEA' | 'Open', - mode :: accept | connect | {connect, reference()}, - parent :: pid(), - transport :: pid(), - service :: #diameter_service{}, - dpr = false :: false | {'Unsigned32'(), 'Unsigned32'()}}). - %% | hop by hop and end to end identifiers - -%% There are non-3588 states possible as a consequence of 5.6.1 of the -%% standard and the corresponding problem for incoming CEA's: we don't -%% know who we're talking to until either a CER or CEA has been -%% received. The CEA problem in particular makes it impossible to -%% follow the state machine exactly as documented in 3588: there can -%% be no election until the CEA arrives and we have an Origin-Host to -%% elect. - -%% -%% Once upon a time start/2 started a process akin to that started by -%% start/3 below, which in turn started a watchdog/transport process -%% with the result that the watchdog could send DWR/DWA regardless of -%% whether or not the corresponding Peer State Machine was in its open -%% state; that is, before capabilities exchange had taken place. This -%% is not what RFC's 3588 and 3539 say (albeit not very clearly). -%% Watchdog messages are only exchanged on *open* connections, so the -%% 3539 state machine is more naturally placed on top of the 3588 Peer -%% State Machine rather than closer to the transport. This is what we -%% now do below: connect/accept call diameter_watchdog and return the -%% pid of the watchdog process, and the watchdog in turn calls start/3 -%% below to start the process implementing the Peer State Machine. The -%% former is a "peer" in diameter_service while the latter is a -%% "conn". In a sense, diameter_service sees the watchdog as -%% implementing the Peer State Machine and the process implemented -%% here as being the transport, not being aware of the watchdog at -%% all. -%% - -%%% --------------------------------------------------------------------------- -%%% # start({connect|accept, Ref}, Opts, Service) -%%% -%%% Output: Pid -%%% --------------------------------------------------------------------------- - -%% diameter_config requires a non-empty list of applications on the -%% service but diameter_service then constrains the list to any -%% specified on the transport in question. Check here that the list is -%% still non-empty. - -start({_, Ref} = Type, Opts, #diameter_service{applications = Apps} = Svc) -> - [] /= Apps orelse ?ERROR({no_apps, Type, Opts}), - T = {self(), Type, Opts, Svc}, - {ok, Pid} = diameter_peer_fsm_sup:start_child(T), - diameter_stats:reg(Pid, Ref), - Pid. - -start_link(T) -> - {ok, _} = proc_lib:start_link(?MODULE, - init, - [T], - infinity, - diameter_lib:spawn_opts(server, [])). - -%%% --------------------------------------------------------------------------- -%%% --------------------------------------------------------------------------- - -%% init/1 - -init(T) -> - proc_lib:init_ack({ok, self()}), - gen_server:enter_loop(?MODULE, [], i(T)). - -i({WPid, {M, _} = T, Opts, #diameter_service{capabilities = Caps} = Svc0}) -> - putr(dwa, dwa(Caps)), - {ok, TPid, Svc} = start_transport(T, Opts, Svc0), - erlang:monitor(process, TPid), - erlang:monitor(process, WPid), - #state{parent = WPid, - transport = TPid, - mode = M, - service = Svc}. -%% The transport returns its local ip addresses so that different -%% transports on the same service can use different local addresses. -%% The local addresses are put into Host-IP-Address avps here when -%% sending capabilities exchange messages. -%% -%% Invalid transport config may cause us to crash but note that the -%% watchdog start (start/2) succeeds regardless so as not to crash the -%% service. - -start_transport(T, Opts, Svc) -> - case diameter_peer:start(T, Opts, Svc) of - {ok, TPid} -> - {ok, TPid, Svc}; - {ok, TPid, [_|_] = Addrs} -> - #diameter_service{capabilities = Caps0} = Svc, - Caps = Caps0#diameter_caps{host_ip_address = Addrs}, - {ok, TPid, Svc#diameter_service{capabilities = Caps}}; - No -> - exit({shutdown, No}) - end. - -%% handle_call/3 - -handle_call(_, _, State) -> - {reply, nok, State}. - -%% handle_cast/2 - -handle_cast(_, State) -> - {noreply, State}. - -%% handle_info/1 - -handle_info(T, #state{} = State) -> - try transition(T, State) of - ok -> - {noreply, State}; - #state{state = X} = S -> - ?LOGC(X =/= State#state.state, transition, X), - {noreply, S}; - {stop, Reason} -> - ?LOG(stop, Reason), - x(Reason, State); - stop -> - ?LOG(stop, T), - x(T, State) - catch - throw: {?MODULE, close = C, Reason} -> - ?LOG(C, {Reason, T}), - x(Reason, State); - throw: {?MODULE, abort, Reason} -> - {stop, {shutdown, Reason}, State} - end. - -x(Reason, #state{} = S) -> - close_wd(Reason, S), - {stop, {shutdown, Reason}, S}. - -%% terminate/2 - -terminate(_, _) -> - ok. - -%% code_change/3 - -code_change(_, State, _) -> - {ok, State}. - -%%% --------------------------------------------------------------------------- -%%% --------------------------------------------------------------------------- - -putr(Key, Val) -> - put({?MODULE, Key}, Val). - -getr(Key) -> - get({?MODULE, Key}). - -%% transition/2 - -%% Connection to peer. -transition({diameter, {TPid, connected, Remote}}, - #state{state = PS, - mode = M} - = S) -> - 'Wait-Conn-Ack' = PS, %% assert - connect = M, %% - send_CER(S#state{mode = {M, Remote}, - transport = TPid}); - -%% Connection from peer. -transition({diameter, {TPid, connected}}, - #state{state = PS, - mode = M, - parent = Pid} - = S) -> - 'Wait-Conn-Ack' = PS, %% assert - accept = M, %% - Pid ! {accepted, self()}, - start_timer(S#state{state = recv_CER, - transport = TPid}); - -%% Incoming message from the transport. -transition({diameter, {recv, Pkt}}, S) -> - recv(Pkt, S); - -%% Timeout when still in the same state ... -transition({timeout, PS}, #state{state = PS}) -> - stop; - -%% ... or not. -transition({timeout, _}, _) -> - ok; - -%% Outgoing message. -transition({send, Msg}, #state{transport = TPid}) -> - send(TPid, Msg), - ok; - -%% Request for graceful shutdown. -transition({shutdown, Pid}, #state{parent = Pid, dpr = false} = S) -> - dpr(?GOAWAY, S); -transition({shutdown, Pid}, #state{parent = Pid}) -> - ok; - -%% Application shutdown. -transition(shutdown, #state{dpr = false} = S) -> - dpr(?REBOOT, S); -transition(shutdown, _) -> %% DPR already send: ensure expected timeout - dpa_timer(), - ok; - -%% Request to close the transport connection. -transition({close = T, Pid}, #state{parent = Pid, - transport = TPid} - = S) -> - diameter_peer:close(TPid), - close(T,S); - -%% DPA reception has timed out. -transition(dpa_timeout, _) -> - stop; - -%% Someone wants to know a resolved port: forward to the transport process. -transition({resolve_port, _Pid} = T, #state{transport = TPid}) -> - TPid ! T, - ok; - -%% Parent or transport has died. -transition({'DOWN', _, process, P, _}, - #state{parent = Pid, - transport = TPid}) - when P == Pid; - P == TPid -> - stop; - -%% State query. -transition({state, Pid}, #state{state = S, transport = TPid}) -> - Pid ! {self(), [S, TPid]}, - ok. - -%% Crash on anything unexpected. - -%% send_CER/1 - -send_CER(#state{mode = {connect, Remote}, - service = #diameter_service{capabilities = Caps}, - transport = TPid} - = S) -> - req_send_CER(Caps#diameter_caps.origin_host, Remote) - orelse - close(connected, S), - CER = build_CER(S), - ?LOG(send, 'CER'), - send(TPid, encode(CER)), - start_timer(S#state{state = 'Wait-CEA'}). - -%% Register ourselves as connecting to the remote endpoint in -%% question. This isn't strictly necessary since a peer implementing -%% the 3588 Peer State Machine should reject duplicate connection's -%% from the same peer but there's little point in us setting up a -%% duplicate connection in the first place. This could also include -%% the transport protocol being used but since we're blind to -%% transport just avoid duplicate connections to the same host/port. -req_send_CER(OriginHost, Remote) -> - register_everywhere({?MODULE, connection, OriginHost, {remote, Remote}}). - -%% start_timer/1 - -start_timer(#state{state = PS} = S) -> - erlang:send_after(?EVENT_TIMEOUT, self(), {timeout, PS}), - S. - -%% build_CER/1 - -build_CER(#state{service = #diameter_service{capabilities = Caps}}) -> - {ok, CER} = diameter_capx:build_CER(Caps), - CER. - -%% encode/1 - -encode(Rec) -> - #diameter_packet{bin = Bin} = diameter_codec:encode(?BASE, Rec), - Bin. - -%% recv/2 - -%% RFC 3588 has result code 5015 for an invalid length but if a -%% transport is detecting message boundaries using the length header -%% then a length error will likely lead to further errors. - -recv(#diameter_packet{header = #diameter_header{length = Len} - = Hdr, - bin = Bin}, - S) - when Len < 20; - (0 /= Len rem 4 orelse bit_size(Bin) /= 8*Len) -> - discard(invalid_message_length, recv, [size(Bin), - bit_size(Bin) rem 8, - Hdr, - S]); - -recv(#diameter_packet{header = #diameter_header{} = Hdr} - = Pkt, - #state{parent = Pid} - = S) -> - Name = diameter_codec:msg_name(Hdr), - Pid ! {recv, self(), Name, Pkt}, - diameter_stats:incr({msg_id(Name, Hdr), recv}), %% count received - rcv(Name, Pkt, S); - -recv(#diameter_packet{header = undefined, - bin = Bin} - = Pkt, - S) -> - recv(Pkt#diameter_packet{header = diameter_codec:decode_header(Bin)}, S); - -recv(Bin, S) - when is_binary(Bin) -> - recv(#diameter_packet{bin = Bin}, S); - -recv(#diameter_packet{header = false} = Pkt, S) -> - discard(truncated_header, recv, [Pkt, S]). - -msg_id({_,_,_} = T, _) -> - T; -msg_id(_, Hdr) -> - diameter_codec:msg_id(Hdr). - -%% Treat invalid length as a transport error and die. Especially in -%% the TCP case, in which there's no telling where the next message -%% begins in the incoming byte stream, keeping a crippled connection -%% alive may just make things worse. - -discard(Reason, F, A) -> - diameter_stats:incr(Reason), - diameter_lib:warning_report(Reason, {?MODULE, F, A}), - throw({?MODULE, abort, Reason}). - -%% rcv/3 - -%% Incoming CEA. -rcv('CEA', Pkt, #state{state = 'Wait-CEA'} = S) -> - handle_CEA(Pkt, S); - -%% Incoming CER -rcv('CER' = N, Pkt, #state{state = recv_CER} = S) -> - handle_request(N, Pkt, S); - -%% Anything but CER/CEA in a non-Open state is an error, as is -%% CER/CEA in anything but recv_CER/Wait-CEA. -rcv(Name, _, #state{state = PS} = S) - when PS /= 'Open'; - Name == 'CER'; - Name == 'CEA' -> - close({Name, PS}, S); - -rcv(N, Pkt, S) - when N == 'DWR'; - N == 'DPR' -> - handle_request(N, Pkt, S); - -%% DPA even though we haven't sent DPR: ignore. -rcv('DPA', _Pkt, #state{dpr = false}) -> - ok; - -%% DPA in response to DPR. We could check the sequence numbers but -%% don't bother, just close. -rcv('DPA' = N, _Pkt, #state{transport = TPid}) -> - diameter_peer:close(TPid), - {stop, N}; - -rcv(_, _, _) -> - ok. - -%% send/2 - -%% Msg here could be a #diameter_packet or a binary depending on who's -%% sending. In particular, the watchdog will send DWR as a binary -%% while messages coming from clients will be in a #diameter_packet. -send(Pid, Msg) -> - diameter_stats:incr({diameter_codec:msg_id(Msg), send}), - diameter_peer:send(Pid, Msg). - -%% handle_request/3 - -handle_request(Type, #diameter_packet{} = Pkt, S) -> - ?LOG(recv, Type), - send_answer(Type, diameter_codec:decode(?BASE, Pkt), S). - -%% send_answer/3 - -send_answer(Type, ReqPkt, #state{transport = TPid} = S) -> - #diameter_packet{header = #diameter_header{version = V, - end_to_end_id = Eid, - hop_by_hop_id = Hid, - is_proxiable = P}, - transport_data = TD} - = ReqPkt, - - {Answer, PostF} = build_answer(Type, V, ReqPkt, S), - - Pkt = #diameter_packet{header = #diameter_header{version = V, - end_to_end_id = Eid, - hop_by_hop_id = Hid, - is_proxiable = P}, - msg = Answer, - transport_data = TD}, - - send(TPid, diameter_codec:encode(?BASE, Pkt)), - eval(PostF, S). - -eval([F|A], S) -> - apply(F, A ++ [S]); -eval(ok, S) -> - S. - -%% build_answer/4 - -build_answer('CER', - ?DIAMETER_VERSION, - #diameter_packet{msg = CER, - header = #diameter_header{is_error = false}, - errors = []} - = Pkt, - #state{service = Svc} - = S) -> - #diameter_service{capabilities = #diameter_caps{origin_host = OH}} - = Svc, - - {SupportedApps, #diameter_caps{origin_host = DH} = RCaps, CEA} - = recv_CER(CER, S), - - try - [] == SupportedApps - andalso ?THROW({no_common_application, 5010}), - register_everywhere({?MODULE, connection, OH, DH}) - orelse ?THROW({election_lost, 4003}), - {CEA, [fun open/4, Pkt, SupportedApps, RCaps]} - catch - ?FAILURE({Reason, RC}) -> - {answer('CER', S) ++ [{'Result-Code', RC}], - [fun close/2, {'CER', Reason, DH}]} - end; - -%% The error checks below are similar to those in diameter_service for -%% other messages. Should factor out the commonality. - -build_answer(Type, V, #diameter_packet{header = H, errors = Es} = Pkt, S) -> - FailedAvp = failed_avp([A || {_,A} <- Es]), - Ans = answer(answer(Type, S), V, H, Es), - {set(Ans, FailedAvp), if 'CER' == Type -> - [fun close/2, {Type, V, Pkt}]; - true -> - ok - end}. - -failed_avp([] = No) -> - No; -failed_avp(Avps) -> - [{'Failed-AVP', [[{'AVP', Avps}]]}]. - -set(Ans, []) -> - Ans; -set(['answer-message' | _] = Ans, FailedAvp) -> - Ans ++ [{'AVP', [FailedAvp]}]; -set([_|_] = Ans, FailedAvp) -> - Ans ++ FailedAvp. - -answer([_, OH, OR | _], _, #diameter_header{is_error = true}, _) -> - ['answer-message', OH, OR, {'Result-Code', 3008}]; - -answer([_, OH, OR | _], _, _, [Bs|_]) - when is_bitstring(Bs) -> - ['answer-message', OH, OR, {'Result-Code', 3009}]; - -answer(Ans, ?DIAMETER_VERSION, _, Es) -> - Ans ++ [{'Result-Code', rc(Es)}]; - -answer(Ans, _, _, _) -> - Ans ++ [{'Result-Code', 5011}]. %% DIAMETER_UNSUPPORTED_VERSION - -rc([]) -> - 2001; %% DIAMETER_SUCCESS -rc([{RC,_}|_]) -> - RC; -rc([RC|_]) -> - RC. - -%% 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. - -%% 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. - -%% ELECTION_LOST 4003 -%% The peer has determined that it has lost the election process and -%% has therefore disconnected the transport connection. - -%% DIAMETER_NO_COMMON_APPLICATION 5010 -%% This error is returned when a CER message is received, and there -%% are no common applications supported between the peers. - -%% DIAMETER_UNSUPPORTED_VERSION 5011 -%% This error is returned when a request was received, whose version -%% number is unsupported. - -%% answer/2 - -answer('DWR', _) -> - getr(dwa); - -answer(Name, #state{service = #diameter_service{capabilities = Caps}}) -> - a(Name, Caps). - -a('CER', #diameter_caps{vendor_id = Vid, - origin_host = Host, - origin_realm = Realm, - host_ip_address = Addrs, - product_name = Name}) -> - ['CEA', {'Origin-Host', Host}, - {'Origin-Realm', Realm}, - {'Host-IP-Address', Addrs}, - {'Vendor-Id', Vid}, - {'Product-Name', Name}]; - -a('DPR', #diameter_caps{origin_host = Host, - origin_realm = Realm}) -> - ['DPA', {'Origin-Host', Host}, - {'Origin-Realm', Realm}]. - -%% recv_CER/2 - -recv_CER(CER, #state{service = Svc}) -> - {ok, T} = diameter_capx:recv_CER(CER, Svc), - T. - -%% handle_CEA/1 - -handle_CEA(#diameter_packet{header = #diameter_header{version = V}, - bin = Bin} - = Pkt, - #state{service = Svc} - = S) - when is_binary(Bin) -> - ?LOG(recv, 'CEA'), - - ?DIAMETER_VERSION == V orelse close({version, V}, S), - - #diameter_packet{msg = CEA, errors = Errors} - = DPkt - = diameter_codec:decode(?BASE, Pkt), - - [] == Errors orelse close({errors, Errors}, S), - - {SApps, #diameter_caps{origin_host = DH} = RCaps} = recv_CEA(CEA, S), - - %% Ensure that we don't already have a connection to the peer in - %% question. This isn't the peer election of 3588 except in the - %% sense that, since we don't know who we're talking to until we - %% receive a CER/CEA, the first that arrives wins the right to a - %% connection with the peer. - - #diameter_service{capabilities = #diameter_caps{origin_host = OH}} - = Svc, - - register_everywhere({?MODULE, connection, OH, DH}) - orelse - close({'CEA', DH}, S), - - open(DPkt, SApps, RCaps, S). - -%% recv_CEA/2 - -recv_CEA(CEA, #state{service = Svc} = S) -> - case diameter_capx:recv_CEA(CEA, Svc) of - {ok, {[], _}} -> - close({'CEA', no_common_application}, S); - {ok, T} -> - T; - {error, Reason} -> - close({'CEA', Reason}, S) - end. - -%% open/4 - -open(Pkt, SupportedApps, RCaps, #state{parent = Pid, - service = Svc} - = S) -> - #diameter_service{capabilities = #diameter_caps{origin_host = OH} - = LCaps} - = Svc, - #diameter_caps{origin_host = DH} - = RCaps, - Pid ! {open, self(), {OH,DH}, {capz(LCaps, RCaps), SupportedApps, Pkt}}, - S#state{state = 'Open'}. - -capz(#diameter_caps{} = L, #diameter_caps{} = R) -> - #diameter_caps{} - = list_to_tuple([diameter_caps | lists:zip(tl(tuple_to_list(L)), - tl(tuple_to_list(R)))]). - -%% close/2 - -%% Tell the watchdog that our death isn't due to transport failure. -close(Reason, #state{parent = Pid}) -> - close_wd(Reason, Pid), - throw({?MODULE, close, Reason}). - -%% close_wd/2 - -%% Ensure the watchdog dies if DPR has been sent ... -close_wd(_, #state{dpr = false}) -> - ok; -close_wd(Reason, #state{parent = Pid}) -> - close_wd(Reason, Pid); - -%% ... or otherwise -close_wd(Reason, Pid) -> - Pid ! {close, self(), Reason}. - -%% dwa/1 - -dwa(#diameter_caps{origin_host = OH, - origin_realm = OR, - origin_state_id = OSI}) -> - ['DWA', {'Origin-Host', OH}, - {'Origin-Realm', OR}, - {'Origin-State-Id', OSI}]. - -%% dpr/2 - -dpr(Cause, #state{transport = TPid, - service = #diameter_service{capabilities = Caps}} - = S) -> - #diameter_caps{origin_host = OH, - origin_realm = OR} - = Caps, - - Bin = encode(['DPR', {'Origin-Host', OH}, - {'Origin-Realm', OR}, - {'Disconnect-Cause', Cause}]), - send(TPid, Bin), - dpa_timer(), - ?LOG(send, 'DPR'), - S#state{dpr = diameter_codec:sequence_numbers(Bin)}. - -dpa_timer() -> - erlang:send_after(?DPA_TIMEOUT, self(), dpa_timeout). - -%% register_everywhere/1 -%% -%% Register a term and ensure it's not registered elsewhere. Note that -%% two process that simultaneously register the same term may well -%% both fail to do so this isn't foolproof. - -register_everywhere(T) -> - diameter_reg:add_new(T) - andalso unregistered(T). - -unregistered(T) -> - {ResL, _} = rpc:multicall(?MODULE, match, [{node(), T}]), - lists:all(fun(L) -> [] == L end, ResL). - -match({Node, _}) - when Node == node() -> - []; -match({_, T}) -> - try - diameter_reg:match(T) - catch - _:_ -> [] - end. |