diff options
Diffstat (limited to 'lib/diameter')
| -rw-r--r-- | lib/diameter/doc/src/diameter_app.xml | 40 | ||||
| -rw-r--r-- | lib/diameter/src/app/diameter_service.erl | 83 |
2 files changed, 55 insertions, 68 deletions
diff --git a/lib/diameter/doc/src/diameter_app.xml b/lib/diameter/doc/src/diameter_app.xml index f2bada84ae..a9ae0ebbec 100644 --- a/lib/diameter/doc/src/diameter_app.xml +++ b/lib/diameter/doc/src/diameter_app.xml @@ -472,11 +472,11 @@ callback returned false.</p> <v>Packet = packet()</v> <v>SvcName = term()</v> <v>Peer = peer()</v> -<v>Action = Reply | {relay, Opts} | discard | {eval, Action, ContF}</v> +<v>Action = Reply | {relay, Opts} | discard | {eval, Action, PostF}</v> <v>Reply = {reply, message()} | {protocol_error, 3000..3999}</v> <v>Opts = diameter:call_opts()</v> -<v>ContF = diameter:evaluable()</v> +<v>PostF = diameter:evaluable()</v> </type> <desc> <p> @@ -564,26 +564,28 @@ will cause the request process in question to fail.</p> <tag><c>{relay, Opts}</c></tag> <item> <p> -Relay a request to another peer. -The appropriate Route-Record AVP will be added to the relayed request -by diameter and <seealso marker="#pick_peer">pick_peer/4</seealso> -and <seealso marker="#prepare_request">prepare_request/3</seealso> -callback will take place just as if <seealso +Relay a request to another peer in the role of a Diameter relay agent. +If a routing loop is detected then the request is answered with +3005 (DIAMETER_LOOP_DETECTED). +Otherwise a Route-Record AVP (containing the sending peer's Origin-Host) is +added to the request and <seealso marker="#pick_peer">pick_peer/4</seealso> +and subsequent callbacks take place just as if <seealso marker="diameter#call">diameter:call/4</seealso> had been called explicitly. -However, returning a <c>relay</c> tuple also causes the End-to-End -Identifier to be preserved in the header of the relayed request as -required by RFC 3588.</p> +The End-to-End Identifier of the incoming request is preserved in the +header of the relayed request.</p> <p> -The returned <c>Opts</c> should not specify <c>detach</c> and -the <seealso marker="#handle_answer">handle_answer/4</seealso> -callback following from a relayed request must return its first +The returned <c>Opts</c> should not specify <c>detach</c>. +A subsequent <seealso marker="#handle_answer">handle_answer/4</seealso> +callback for the relayed request must return its first argument, the <c>diameter_packet</c> record containing the answer message. Note that the <c>extra</c> option can be specified to supply arguments -that can distinguish the relay case from others if so desired, -although the form of the request message may be sufficient.</p> +that can distinguish the relay case from others if so desired. +Any other return value (for example, from a +<seealso marker="#handle_error">handle_error/4</seealso> callback) +causes the request to be answered with 3002 (DIAMETER_UNABLE_TO_DELIVER).</p> </item> <tag><c>discard</c></tag> @@ -592,18 +594,18 @@ although the form of the request message may be sufficient.</p> Discard the request.</p> </item> -<tag><c>{eval, Action, ContF}</c></tag> +<tag><c>{eval, Action, PostF}</c></tag> <item> <p> Handle the request as if <c>Action</c> has been returned and then -evaluate <c>ContF</c> in the request process.</p> +evaluate <c>PostF</c> in the request process.</p> </item> </taglist> <p> -Note that diameter will respond to protocol errors in an incoming -request without invoking <c>handle_request/3</c>.</p> +Note that protocol errors detected by diameter will result in an +answer message without <c>handle_request/3</c> being invoked.</p> </desc> </func> diff --git a/lib/diameter/src/app/diameter_service.erl b/lib/diameter/src/app/diameter_service.erl index 0569d595b9..6498143e2e 100644 --- a/lib/diameter/src/app/diameter_service.erl +++ b/lib/diameter/src/app/diameter_service.erl @@ -1688,9 +1688,9 @@ recv_request({Id, Alias}, T, TPid, Apps, Caps, Pkt) -> %% DIAMETER_APPLICATION_UNSUPPORTED 3007 %% A request was sent for an application that is not supported. -recv_request(false, {_, OH, OR}, TPid, _, _, Pkt) -> - ?LOG({error, application}, Pkt), - reply(answer_message({OH, OR, 3007}, collect_avps(Pkt)), ?BASE, TPid, Pkt). +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 @@ -1709,13 +1709,9 @@ collect_avps(Pkt) -> %% set to an unrecognized value, or that is inconsistent with the %% AVP's definition. %% -recv_request({_, OH, OR}, {TPid, _}, _, #diameter_packet{errors = [Bs | _], - bin = Bin, - avps = Avps} - = Pkt) +recv_request(T, {TPid, _}, _, #diameter_packet{errors = [Bs | _]} = Pkt) when is_bitstring(Bs) -> - ?LOG({error, invalid_avp_bits}, Bin), - reply(answer_message({OH, OR, 3009}, Avps), ?BASE, TPid, Pkt); + 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. @@ -1725,18 +1721,15 @@ recv_request({_, OH, OR}, {TPid, _}, _, #diameter_packet{errors = [Bs | _], %% recognize or support. This MUST be used when a Diameter node %% receives an experimental command that it does not understand. %% -recv_request({_, OH, OR}, +recv_request(T, {TPid, _}, #diameter_app{id = Id}, #diameter_packet{header = #diameter_header{is_proxiable = P}, - msg = M, - avps = Avps, - bin = Bin} + msg = M} = Pkt) when ?APP_ID_RELAY /= Id, undefined == M; ?APP_ID_RELAY == Id, not P -> - ?LOG({error, command_unsupported}, Bin), - reply(answer_message({OH, OR, 3001}, Avps), ?BASE, TPid, Pkt); + protocol_error(3001, T, TPid, Pkt); %% Error bit was set on a request. %% @@ -1745,15 +1738,12 @@ recv_request({_, OH, OR}, %% either set to an invalid combination, or to a value that is %% inconsistent with the command code's definition. %% -recv_request({_, OH, OR}, +recv_request(T, {TPid, _}, _, - #diameter_packet{header = #diameter_header{is_error = true}, - avps = Avps, - bin = Bin} + #diameter_packet{header = #diameter_header{is_error = true}} = Pkt) -> - ?LOG({error, error_bit}, Bin), - reply(answer_message({OH, OR, 3008}, Avps), ?BASE, TPid, 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 @@ -1881,7 +1871,7 @@ resend(true, _, _, T, {TPid, _}, Pkt) -> %% Route-Record loop resend(false, Opts, App, - {SvcName, _, _}, + {SvcName, _, _} = T, {TPid, #diameter_caps{origin_host = {_, OH}}}, #diameter_packet{header = Hdr0, avps = Avps} @@ -1890,46 +1880,41 @@ resend(false, Seq = diameter_session:sequence(), Hdr = Hdr0#diameter_header{hop_by_hop_id = Seq}, Msg = [Hdr, Route | Avps], - %% Filter sender as ineligible receiver. - reply(call(SvcName, App, Msg, [{filter, {neg, {host, OH}}} | Opts]), - TPid, - Pkt). + resend(call(SvcName, App, Msg, Opts), T, TPid, Pkt). %% The incoming request is relayed with the addition of a -%% Route-Record. Note the requirement on the return from call/4. -%% This places a requirement on the values returned by the -%% handle_answer and handle_error callbacks of the application module -%% in question. +%% 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. -%% reply/3 +%% resend/4 %% %% Relay a reply to a relayed request. %% Answer from the peer: reset the hop by hop identifier and send. -reply(#diameter_packet{bin = B} - = Pkt, - TPid, - #diameter_packet{header = #diameter_header{hop_by_hop_id = Id}, - transport_data = TD}) -> +resend(#diameter_packet{bin = B} + = Pkt, + _, + TPid, + #diameter_packet{header = #diameter_header{hop_by_hop_id = Id}, + transport_data = TD}) -> send(TPid, Pkt#diameter_packet{bin = diameter_codec:hop_by_hop_id(Id, B), transport_data = TD}); %% TODO: counters -%% Not. Ignoring the error feels harsh but there is no appropriate -%% Result-Code for a protocol error (which this isn't really anyway) -%% and the RFC doesn't provide any guidance how to act. A weakness -%% here is that we don't deal well with a decode error: the request -%% will simply timeout on the peer's end. Better would be to just send -%% the answer (with modified hop by hop identifier) on regardless, at -%% least in the relay case in which there's no examination of the -%% answer. In the proxy case it's not clear that the callback won't -%% examine the answer. Just be quiet here since a decode error causes -%% the request process to crash (or not depending on the error and -%% config and/or handle_answer callback). -reply(_, _, _) -> - ok. +%% Or not: DIAMETER_UNABLE_TO_DELIVER. +resend(_, T, TPid, Pkt) -> + protocol_error(3002, T, TPid, Pkt). %% is_loop/4 %% |