diff options
Diffstat (limited to 'lib/diameter/include/diameter_gen.hrl')
| -rw-r--r-- | lib/diameter/include/diameter_gen.hrl | 117 |
1 files changed, 84 insertions, 33 deletions
diff --git a/lib/diameter/include/diameter_gen.hrl b/lib/diameter/include/diameter_gen.hrl index c8f706dc3e..7e91ce375f 100644 --- a/lib/diameter/include/diameter_gen.hrl +++ b/lib/diameter/include/diameter_gen.hrl @@ -30,6 +30,10 @@ %% error or not. See is_strict/0. -define(STRICT_KEY, strict). +%% Key that says whether or not we should do a best-effort decode +%% within Failed-AVP. +-define(FAILED_KEY, failed). + -type parent_name() :: atom(). %% parent = Message or AVP -type parent_record() :: tuple(). %% -type avp_name() :: atom(). @@ -286,15 +290,7 @@ decode(Name, 'AVP', Avp, Acc) -> %% d/3 -%% Don't try to decode the value of a Failed-AVP component since it -%% probably won't. Note that matching on 'Failed-AVP' assumes that -%% this is the RFC AVP, with code 279. Strictly, this doesn't need to -%% be the case, so we're assuming no one defines another Failed-AVP. -d('Failed-AVP' = Name, Avp, Acc) -> - decode_AVP(Name, Avp, Acc); - -%% Or try to decode. -d(Name, Avp, {Avps, Acc}) -> +d(Name, Avp, Acc) -> #diameter_avp{name = AvpName, data = Data, type = Type, @@ -307,51 +303,81 @@ d(Name, Avp, {Avps, Acc}) -> %% value around through the entire decode. The solution here is %% simple in comparison, both to implement and to understand. - Reset = relax(Type, M), + Strict = relax(Type, M), + %% Use the process dictionary again to keep track of whether we're + %% decoding within Failed-AVP and should ignore decode errors + %% altogether. + + Failed = relax(Name), %% Not AvpName or else a failed Failed-AVP + %% decode is packed into 'AVP'. try avp(decode, Data, AvpName) of V -> + {Avps, T} = Acc, {H, A} = ungroup(V, Avp), - {[H | Avps], pack_avp(Name, A, Acc)} + {[H | Avps], pack_avp(Name, A, T)} catch error: Reason -> - %% Failures here won't be visible since they're a "normal" - %% occurrence if the peer sends a faulty AVP that we need to - %% respond sensibly to. Log the occurence for traceability, - %% but the peer will also receive info in the resulting - %% answer-message. - diameter_lib:log({decode, failure}, - ?MODULE, - ?LINE, - {Reason, Avp, erlang:get_stacktrace()}), - {Rec, Failed} = Acc, - {[Avp|Avps], {Rec, [rc(Reason, Avp) | Failed]}} + d(undefined == Failed orelse is_failed(), Reason, Name, Avp, Acc) after - relax(Reset) + reset(?STRICT_KEY, Strict), + reset(?FAILED_KEY, Failed) end. +%% Ignore a decode error within Failed-AVP ... +d(true, _, Name, Avp, Acc) -> + decode_AVP(Name, Avp, Acc); + +%% ... or not. Failures here won't be visible since they're a "normal" +%% occurrence if the peer sends a faulty AVP that we need to respond +%% sensibly to. Log the occurence for traceability, but the peer will +%% also receive info in the resulting answer message. +d(false, Reason, Name, Avp, {Avps, Acc}) -> + Stack = diameter_lib:get_stacktrace(), + diameter_lib:log(decode_error, + ?MODULE, + ?LINE, + {Reason, Name, Avp#diameter_avp.name, Stack}), + {Rec, Failed} = Acc, + {[Avp|Avps], {Rec, [rc(Reason, Avp) | Failed]}}. + %% Set false in the process dictionary as soon as we see a Grouped AVP %% that doesn't set the M-bit, so that is_strict() can say whether or %% not to ignore the M-bit on an encapsulated AVP. relax('Grouped', M) -> - V = getr(?STRICT_KEY), - if V == undefined andalso not M -> + case getr(?STRICT_KEY) of + undefined when not M -> putr(?STRICT_KEY, M); - true -> + _ -> false end; relax(_, _) -> false. -%% Reset strictness. -relax(undefined) -> - eraser(?STRICT_KEY); -relax(false) -> - ok. - is_strict() -> false /= getr(?STRICT_KEY). +%% Set true in the process dictionary as soon as we see Failed-AVP. +%% Matching on 'Failed-AVP' assumes that this is the RFC AVP. +%% Strictly, this doesn't need to be the case. +relax('Failed-AVP') -> + case getr(?FAILED_KEY) of + undefined -> + putr(?FAILED_KEY, true); + true = Yes -> + Yes + end; +relax(_) -> + is_failed(). + +is_failed() -> + true == getr(?FAILED_KEY). + +reset(Key, undefined) -> + eraser(Key); +reset(_, _) -> + ok. + %% decode_AVP/3 %% %% Don't know this AVP: see if it can be packed in an 'AVP' field @@ -410,6 +436,23 @@ pack_avp(_, Arity, Avp, Acc) -> %% pack_AVP/3 +%% Length failure was induced because of a header/payload length +%% mismatch. The AVP Length is reset to match the received data if +%% this AVP is encoded in an answer message, since the length is +%% computed. +%% +%% Data is a truncated header if command_code = undefined, otherwise +%% payload bytes. The former is padded to the length of a header if +%% the AVP reaches an outgoing encode in diameter_codec. +%% +%% RFC 6733 says that an AVP returned with 5014 can contain a minimal +%% payload for the AVP's type, but in this case we don't know the +%% type. + +pack_AVP(_, #diameter_avp{data = <<0:1, Data/binary>>} = Avp, Acc) -> + {Rec, Failed} = Acc, + {Rec, [{5014, Avp#diameter_avp{data = Data}} | Failed]}; + pack_AVP(Name, #diameter_avp{is_mandatory = M} = Avp, Acc) -> case pack_arity(Name, M) of 0 -> @@ -422,7 +465,15 @@ pack_AVP(Name, #diameter_avp{is_mandatory = M} = Avp, Acc) -> %% Give Failed-AVP special treatment since it'll contain any %% unrecognized mandatory AVP's. pack_arity(Name, M) -> - case Name /= 'Failed-AVP' andalso M andalso is_strict() of + NF = Name /= 'Failed-AVP' andalso not is_failed(), + %% Not testing just Name /= 'Failed-AVP' means we're changing the + %% packing of AVPs nested within Failed-AVP, but the point of + %% ignoring errors within Failed-AVP is to decode as much as + %% possible, and failing because a mandatory AVP couldn't be + %% packed into a dedicated field defeats that point. Note that we + %% can't just test not is_failed() since this will be 'true' when + %% packing an unknown AVP directly within Failed-AVP. + case NF andalso M andalso is_strict() of true -> 0; false -> |