diff options
Diffstat (limited to 'lib/diameter/include/diameter_gen.hrl')
| -rw-r--r-- | lib/diameter/include/diameter_gen.hrl | 358 |
1 files changed, 281 insertions, 77 deletions
diff --git a/lib/diameter/include/diameter_gen.hrl b/lib/diameter/include/diameter_gen.hrl index c8f706dc3e..39ccdc9873 100644 --- a/lib/diameter/include/diameter_gen.hrl +++ b/lib/diameter/include/diameter_gen.hrl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2010-2014. All Rights Reserved. +%% Copyright Ericsson AB 2010-2015. 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 @@ -25,11 +25,21 @@ -define(THROW(T), throw({?MODULE, T})). +%% Tag common to generated dictionaries. +-define(TAG, diameter_gen). + %% Key to a value in the process dictionary that determines whether or %% not an unrecognized AVP setting the M-bit should be regarded as an -%% error or not. See is_strict/0. +%% error or not. See is_strict/0. This is only used to relax M-bit +%% interpretation inside Grouped AVPs not setting the M-bit. The +%% service_opt() strict_mbit can be used to disable the check +%% globally. -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(). @@ -44,13 +54,20 @@ %% dictionary. putr(K,V) -> - put({?MODULE, K}, V). + put({?TAG, K}, V). getr(K) -> - get({?MODULE, K}). + case get({?TAG, K}) of + undefined -> + V = erase({?MODULE, K}), %% written in old code + V == undefined orelse putr(K,V), + V; + V -> + V + end. eraser(K) -> - erase({?MODULE, K}). + erase({?TAG, K}). %% --------------------------------------------------------------------------- %% # encode_avps/2 @@ -171,9 +188,10 @@ decode_avps(Name, Recs) -> = lists:foldl(fun(T,A) -> decode(Name, T, A) end, {[], {newrec(Name), []}}, Recs), - {Rec, Avps, Failed ++ missing(Rec, Name)}. -%% Append 5005 errors so that a 5014 for the same AVP will take -%% precedence in a Result-Code/Failed-AVP setting. + {Rec, Avps, Failed ++ missing(Rec, Name, Failed)}. +%% Append 5005 errors so that errors are reported in the order +%% encountered. Failed-AVP should typically contain the first +%% encountered error accordg to the RFC. newrec(Name) -> '#new-'(name2rec(Name)). @@ -186,20 +204,36 @@ newrec(Name) -> %% Failed-AVP AVP SHOULD be included in the message. The Failed-AVP %% AVP MUST contain an example of the missing AVP complete with the %% Vendor-Id if applicable. The value field of the missing AVP -%% should be of correct minimum length and contain zeroes. - -missing(Rec, Name) -> - [{5005, empty_avp(F)} || F <- '#info-'(element(1, Rec), fields), - A <- [avp_arity(Name, F)], - false <- [have_arity(A, '#get-'(F, Rec))]]. +%% should be of correct minimum length and contain zeros. + +missing(Rec, Name, Failed) -> + Avps = lists:foldl(fun({_, #diameter_avp{code = C, vendor_id = V}}, A) -> + sets:add_element({C,V}, A) + end, + sets:new(), + Failed), + [{5005, A} || F <- '#info-'(element(1, Rec), fields), + not has_arity(avp_arity(Name, F), '#get-'(F, Rec)), + #diameter_avp{code = C, vendor_id = V} + = A <- [empty_avp(F)], + not sets:is_element({C,V}, Avps)]. %% Maximum arities have already been checked in building the record. -have_arity({Min, _}, L) -> - Min =< length(L); -have_arity(N, V) -> +has_arity({Min, _}, L) -> + has_prefix(Min, L); +has_arity(N, V) -> N /= 1 orelse V /= undefined. +%% Compare a non-negative integer and the length of a list without +%% computing the length. +has_prefix(0, _) -> + true; +has_prefix(_, []) -> + false; +has_prefix(N, L) -> + has_prefix(N-1, tl(L)). + %% empty_avp/1 empty_avp(Name) -> @@ -286,15 +320,7 @@ 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, @@ -307,50 +333,159 @@ 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. - try avp(decode, Data, AvpName) of + Failed = relax(Name), %% Not AvpName or else a failed Failed-AVP + %% decode is packed into 'AVP'. + Mod = dict(Failed), %% Dictionary to decode in. + + %% On decode, a Grouped AVP is represented as a #diameter_avp{} + %% list with AVP as head and component AVPs as tail. On encode, + %% data can be a list of component AVPs. + + try Mod: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 + throw: {?TAG, {grouped, Error, ComponentAvps}} -> + g(is_failed(), Error, Name, trim(Avp), Acc, ComponentAvps); 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(is_failed(), Reason, Name, trim(Avp), Acc) after - relax(Reset) + reset(?STRICT_KEY, Strict), + reset(?FAILED_KEY, Failed) end. +%% trim/1 +%% +%% Remove any extra bit that was added in diameter_codec to induce a +%% 5014 error. + +trim(#diameter_avp{data = <<0:1, Bin/binary>>} = Avp) -> + Avp#diameter_avp{data = Bin}; + +trim(Avps) + when is_list(Avps) -> + lists:map(fun trim/1, Avps); + +trim(Avp) -> + Avp. + +%% dict/1 +%% +%% Retrieve the dictionary for the best-effort decode of Failed-AVP, +%% as put by diameter_codec:decode/2. See that function for the +%% explanation. + +dict(true) -> + case get({diameter_codec, dictionary}) of + undefined -> + ?MODULE; + Mod -> + Mod + end; + +dict(_) -> + ?MODULE. + +%% g/5 + +%% Ignore decode errors within Failed-AVP (best-effort) ... +g(true, [_Error | Rec], Name, Avp, Acc, _ComponentAvps) -> + decode_AVP(Name, Avp#diameter_avp{value = Rec}, Acc); +g(true, _Error, Name, Avp, Acc, _ComponentAvps) -> + decode_AVP(Name, Avp, Acc); + +%% ... or not. +g(false, [Error | _Rec], _Name, Avp, Acc, ComponentAvps) -> + g(Error, Avp, Acc, ComponentAvps); +g(false, Error, _Name, Avp, Acc, ComponentAvps) -> + g(Error, Avp, Acc, ComponentAvps). + +%% g/4 + +g({RC, ErrorData}, Avp, Acc, ComponentAvps) -> + {Avps, {Rec, Errors}} = Acc, + E = Avp#diameter_avp{data = [ErrorData]}, + {[[Avp | trim(ComponentAvps)] | Avps], {Rec, [{RC, E} | Errors]}}. + +%% d/5 + +%% 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, + {Name, Avp#diameter_avp.name, Stack}), + {Rec, Failed} = Acc, + {[Avp|Avps], {Rec, [rc(Reason, Avp) | Failed]}}. + +%% relax/2 + %% 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). + diameter_codec:getopt(strict_mbit) + andalso false /= getr(?STRICT_KEY). + +%% relax/1 +%% +%% 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') -> + putr(?FAILED_KEY, true); + +relax(_) -> + is_failed(). + +%% is_failed/0 +%% +%% Is the AVP currently being decoded nested within Failed-AVP? Note +%% that this is only true when Failed-AVP is the parent. In +%% particular, it's not true when Failed-AVP itself is being decoded +%% (unless nested). + +is_failed() -> + true == getr(?FAILED_KEY). + +%% is_failed/1 + +is_failed(Name) -> + 'Failed-AVP' == Name orelse is_failed(). + +%% reset/2 + +reset(Key, undefined) -> + eraser(Key); +reset(_, _) -> + ok. %% decode_AVP/3 %% @@ -358,14 +493,14 @@ is_strict() -> %% undecoded. Note that the type field is 'undefined' in this case. decode_AVP(Name, Avp, {Avps, Acc}) -> - {[Avp | Avps], pack_AVP(Name, Avp, Acc)}. + {[trim(Avp) | Avps], pack_AVP(Name, Avp, Acc)}. %% rc/1 %% diameter_types will raise an error of this form to communicate %% DIAMETER_INVALID_AVP_LENGTH (5014). A module specified to a -%% @custom_types tag in a spec file can also raise an error of this -%% form. +%% @custom_types tag in a dictionary file can also raise an error of +%% this form. rc({'DIAMETER', 5014 = RC, _}, #diameter_avp{name = AvpName} = Avp) -> {RC, Avp#diameter_avp{data = empty_value(AvpName)}}; @@ -410,8 +545,25 @@ pack_avp(_, Arity, Avp, Acc) -> %% pack_AVP/3 -pack_AVP(Name, #diameter_avp{is_mandatory = M} = Avp, Acc) -> - case pack_arity(Name, M) of +%% 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, name = AvpName} = Avp, Acc) -> + case pack_arity(Name, AvpName, M) of 0 -> {Rec, Failed} = Acc, {Rec, [{if M -> 5001; true -> 5008 end, Avp} | Failed]}; @@ -419,15 +571,31 @@ pack_AVP(Name, #diameter_avp{is_mandatory = M} = Avp, Acc) -> pack(Arity, 'AVP', Avp, Acc) end. -%% 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 - true -> - 0; - false -> - avp_arity(Name, 'AVP') - end. +%% Give Failed-AVP special treatment since (1) it'll contain any +%% unrecognized mandatory AVP's and (2) the RFC 3588 grammar failed to +%% allow for Failed-AVP in an answer-message. + +pack_arity(Name, AvpName, M) -> + + %% 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 + %% is_failed/1 since is_failed/0 will return false when packing + %% 'AVP' within Failed-AVP. + + pack_arity(is_failed(Name) + orelse {Name, AvpName} == {'answer-message', 'Failed-AVP'} + orelse not M + orelse not is_strict(), + Name). + +pack_arity(true, Name) -> + avp_arity(Name, 'AVP'); + +pack_arity(false, _) -> + 0. %% 3588: %% @@ -460,14 +628,17 @@ pack(undefined, 1, FieldName, Avp, Acc) -> %% AVP MUST be included and contain a copy of the first instance of %% the offending AVP that exceeded the maximum number of occurrences %% + pack(_, 1, _, Avp, {Rec, Failed}) -> {Rec, [{5009, Avp} | Failed]}; -pack(L, {_, Max}, _, Avp, {Rec, Failed}) - when length(L) == Max -> - {Rec, [{5009, Avp} | Failed]}; - -pack(L, _, FieldName, Avp, Acc) -> - p(FieldName, fun(V) -> [V|L] end, Avp, Acc). +pack(L, {_, Max}, FieldName, Avp, Acc) -> + case '*' /= Max andalso has_prefix(Max, L) of + true -> + {Rec, Failed} = Acc, + {Rec, [{5009, Avp} | Failed]}; + false -> + p(FieldName, fun(V) -> [V|L] end, Avp, Acc) + end. %% p/4 @@ -483,22 +654,55 @@ value(_, Avp) -> %% # grouped_avp/3 %% --------------------------------------------------------------------------- --spec grouped_avp(decode, avp_name(), binary()) +-spec grouped_avp(decode, avp_name(), bitstring()) -> {avp_record(), [avp()]}; (encode, avp_name(), avp_record() | avp_values()) -> binary() | no_return(). +%% Length error induced by diameter_codec:collect_avps/1: the AVP +%% length in the header was too short (insufficient for the extracted +%% header) or too long (past the end of the message). An empty payload +%% is sufficient according to the RFC text for 5014. +grouped_avp(decode, _Name, <<0:1, _/binary>>) -> + throw({?TAG, {grouped, {5014, []}, []}}); + grouped_avp(decode, Name, Data) -> - {Rec, Avps, []} = decode_avps(Name, diameter_codec:collect_avps(Data)), - {Rec, Avps}; -%% A failed match here will result in 5004. Note that this is the only -%% AVP type that doesn't just return the decoded record, also -%% returning the list of component AVP's. + grouped_decode(Name, diameter_codec:collect_avps(Data)); grouped_avp(encode, Name, Data) -> encode_avps(Name, Data). +%% grouped_decode/2 +%% +%% Note that Grouped is the only AVP type that doesn't just return a +%% decoded value, also returning the list of component diameter_avp +%% records. + +%% Length error in trailing component AVP. +grouped_decode(_Name, {Error, Acc}) -> + {5014, Avp} = Error, + throw({?TAG, {grouped, Error, [Avp | Acc]}}); + +%% 7.5. Failed-AVP AVP + +%% In the case where the offending AVP is embedded within a Grouped AVP, +%% the Failed-AVP MAY contain the grouped AVP, which in turn contains +%% the single offending AVP. The same method MAY be employed if the +%% grouped AVP itself is embedded in yet another grouped AVP and so on. +%% In this case, the Failed-AVP MAY contain the grouped AVP hierarchy up +%% to the single offending AVP. This enables the recipient to detect +%% the location of the offending AVP when embedded in a group. + +%% An error in decoding a component AVP throws the first fauly +%% component, which the catch in d/3 wraps in the Grouped AVP in +%% question. A partially decoded record is only used when ignoring +%% errors in Failed-AVP. +grouped_decode(Name, ComponentAvps) -> + {Rec, Avps, Es} = decode_avps(Name, ComponentAvps), + [] == Es orelse throw({?TAG, {grouped, [{_,_} = hd(Es) | Rec], Avps}}), + {Rec, Avps}. + %% --------------------------------------------------------------------------- %% # empty_group/1 %% --------------------------------------------------------------------------- |