diff options
Diffstat (limited to 'lib/diameter/src/base/diameter_codec.erl')
| -rw-r--r-- | lib/diameter/src/base/diameter_codec.erl | 358 |
1 files changed, 242 insertions, 116 deletions
diff --git a/lib/diameter/src/base/diameter_codec.erl b/lib/diameter/src/base/diameter_codec.erl index 1d647b8c87..1ea5357924 100644 --- a/lib/diameter/src/base/diameter_codec.erl +++ b/lib/diameter/src/base/diameter_codec.erl @@ -1,18 +1,19 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2010-2013. 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 -%% 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/. +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at %% -%% 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. +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. %% %% %CopyrightEnd% %% @@ -22,6 +23,8 @@ -export([encode/2, decode/2, decode/3, + setopts/1, + getopt/1, collect_avps/1, decode_header/1, sequence_numbers/1, @@ -59,6 +62,52 @@ %% +-+-+-+-+-+-+-+-+-+-+-+-+- %%% --------------------------------------------------------------------------- +%%% # setopts/1 +%%% # getopt/1 +%%% --------------------------------------------------------------------------- + +%% These functions are a compromise in the same vein as the use of the +%% process dictionary in diameter_gen.hrl in generated codec modules. +%% Instead of rewriting the entire dictionary generation to pass +%% encode/decode options around, the calling process sets them by +%% calling setopts/1. At current, the only option is whether or not to +%% decode binaries as strings, which is used by diameter_types. + +setopts(Opts) + when is_list(Opts) -> + lists:foreach(fun setopt/1, Opts). + +%% The default string_decode true is for backwards compatibility. +setopt({K, false = B}) + when K == string_decode; + K == strict_mbit -> + setopt(K, B); + +%% Regard anything but the generated RFC 3588 dictionary as modern. +%% This affects the interpretation of defaults during the decode +%% of values of type DiameterURI, this having changed from RFC 3588. +%% (So much for backwards compatibility.) +setopt({common_dictionary, diameter_gen_base_rfc3588}) -> + setopt(rfc, 3588); + +setopt(_) -> + ok. + +setopt(Key, Value) -> + put({diameter, Key}, Value). + +getopt(Key) -> + case get({diameter, Key}) of + undefined when Key == string_decode; + Key == strict_mbit -> + true; + undefined when Key == rfc -> + 6733; + V -> + V + end. + +%%% --------------------------------------------------------------------------- %%% # encode/2 %%% --------------------------------------------------------------------------- @@ -70,12 +119,15 @@ encode(Mod, #diameter_packet{} = Pkt) -> try e(Mod, Pkt) catch + exit: {Reason, Stack, #diameter_header{} = H} = T -> + %% Exit with a header in the reason to let the caller + %% count encode errors. + ?LOG(encode_error, {Reason, Stack, H}), + exit({?MODULE, encode, T}); error: Reason -> - %% Be verbose since a crash report may be truncated and - %% encode errors are self-inflicted. - X = {?MODULE, encode, {Reason, ?STACK}}, - diameter_lib:error_report(X, {?MODULE, encode, [Mod, Pkt]}), - exit(X) + T = {Reason, diameter_lib:get_stacktrace()}, + ?LOG(encode_error, T), + exit({?MODULE, encode, T}) end; encode(Mod, Msg) -> @@ -87,53 +139,62 @@ encode(Mod, Msg) -> msg = Msg}). e(_, #diameter_packet{msg = [#diameter_header{} = Hdr | As]} = Pkt) -> - Avps = encode_avps(As), - Length = size(Avps) + 20, - - #diameter_header{version = Vsn, - cmd_code = Code, - application_id = Aid, - hop_by_hop_id = Hid, - end_to_end_id = Eid} - = Hdr, - - Flags = make_flags(0, Hdr), - - Pkt#diameter_packet{header = Hdr, - bin = <<Vsn:8, Length:24, - Flags:8, Code:24, - Aid:32, - Hid:32, - Eid:32, - Avps/binary>>}; + try encode_avps(reorder(As)) of + Avps -> + Length = size(Avps) + 20, + + #diameter_header{version = Vsn, + cmd_code = Code, + application_id = Aid, + hop_by_hop_id = Hid, + end_to_end_id = Eid} + = Hdr, + + Flags = make_flags(0, Hdr), + + Pkt#diameter_packet{header = Hdr, + bin = <<Vsn:8, Length:24, + Flags:8, Code:24, + Aid:32, + Hid:32, + Eid:32, + Avps/binary>>} + catch + error: Reason -> + exit({Reason, diameter_lib:get_stacktrace(), Hdr}) + end; -e(Mod, #diameter_packet{header = Hdr, msg = Msg} = Pkt) -> +e(Mod, #diameter_packet{header = Hdr0, msg = Msg} = Pkt) -> #diameter_header{version = Vsn, hop_by_hop_id = Hid, end_to_end_id = Eid} - = Hdr, + = Hdr0, MsgName = rec2msg(Mod, Msg), - {Code, Flags0, Aid} = msg_header(Mod, MsgName, Hdr), - Flags = make_flags(Flags0, Hdr), - - Avps = encode_avps(Mod, MsgName, values(Msg)), - Length = size(Avps) + 20, - - Pkt#diameter_packet{header = Hdr#diameter_header - {length = Length, - cmd_code = Code, - application_id = Aid, - is_request = 0 /= ?MASK(7, Flags), - is_proxiable = 0 /= ?MASK(6, Flags), - is_error = 0 /= ?MASK(5, Flags), - is_retransmitted = 0 /= ?MASK(4, Flags)}, - bin = <<Vsn:8, Length:24, - Flags:8, Code:24, - Aid:32, - Hid:32, - Eid:32, - Avps/binary>>}. + {Code, Flags0, Aid} = msg_header(Mod, MsgName, Hdr0), + Flags = make_flags(Flags0, Hdr0), + Hdr = Hdr0#diameter_header{cmd_code = Code, + application_id = Aid, + is_request = 0 /= ?MASK(7, Flags), + is_proxiable = 0 /= ?MASK(6, Flags), + is_error = 0 /= ?MASK(5, Flags), + is_retransmitted = 0 /= ?MASK(4, Flags)}, + Values = values(Msg), + + try encode_avps(Mod, MsgName, Values) of + Avps -> + Length = size(Avps) + 20, + Pkt#diameter_packet{header = Hdr#diameter_header{length = Length}, + bin = <<Vsn:8, Length:24, + Flags:8, Code:24, + Aid:32, + Hid:32, + Eid:32, + Avps/binary>>} + catch + error: Reason -> + exit({Reason, diameter_lib:get_stacktrace(), Hdr}) + end. %% make_flags/2 @@ -171,26 +232,50 @@ values(Avps) -> %% Message as a list of #diameter_avp{} ... encode_avps(_, _, [#diameter_avp{} | _] = Avps) -> - encode_avps(reorder(Avps, [], Avps)); + encode_avps(reorder(Avps)); %% ... or as a tuple list or record. encode_avps(Mod, MsgName, Values) -> Mod:encode_avps(MsgName, Values). %% reorder/1 +%% +%% Reorder AVPs for the relay case using the index field of +%% diameter_avp records. Decode populates this field in collect_avps +%% and presents AVPs in reverse order. A relay then sends the reversed +%% list with a Route-Record AVP prepended. The goal here is just to do +%% lists:reverse/1 in Grouped AVPs and the outer list, but only in the +%% case there are indexed AVPs at all, so as not to reverse lists that +%% have been explicilty sent (unindexed, in the desired order) as a +%% diameter_avp list. The effect is the same as lists:keysort/2, but +%% only on the cases we expect, not a general sort. + +reorder(Avps) -> + case reorder(Avps, []) of + false -> + Avps; + Sorted -> + Sorted + end. -reorder([#diameter_avp{index = 0} | _] = Avps, Acc, _) -> +%% reorder/3 + +%% In case someone has reversed the list already. (Not likely.) +reorder([#diameter_avp{index = 0} | _] = Avps, Acc) -> Avps ++ Acc; -reorder([#diameter_avp{index = N} = A | Avps], Acc, _) +%% Assume indexed AVPs are in reverse order. +reorder([#diameter_avp{index = N} = A | Avps], Acc) when is_integer(N) -> lists:reverse(Avps, [A | Acc]); -reorder([H | T], Acc, Avps) -> - reorder(T, [H | Acc], Avps); +%% An unindexed AVP. +reorder([H | T], Acc) -> + reorder(T, [H | Acc]); -reorder([], Acc, _) -> - Acc. +%% No indexed members. +reorder([], _) -> + false. %% encode_avps/1 @@ -225,15 +310,35 @@ rec2msg(Mod, Rec) -> %% Unsuccessfully decoded AVPs will be placed in #diameter_packet.errors. --spec decode(module(), #diameter_packet{} | bitstring()) +-spec decode(module() | {module(), module()}, #diameter_packet{} | binary()) -> #diameter_packet{}. +%% An Answer setting the E-bit. The application dictionary is needed +%% for the best-effort decode of Failed-AVP, and the best way to make +%% this available to the AVP decode in diameter_gen.hrl, without +%% having to rewrite the entire codec generation, is to place it in +%% the process dictionary. It's the code in diameter_gen.hrl (that's +%% included by every generated codec module) that looks for the entry. +%% Not ideal, but it solves the problem relatively simply. +decode({Mod, Mod}, Pkt) -> + decode(Mod, Pkt); +decode({Mod, AppMod}, Pkt) -> + Key = {?MODULE, dictionary}, + put(Key, AppMod), + try + decode(Mod, Pkt) + after + erase(Key) + end; + +%% Or not: a request, or an answer not setting the E-bit. decode(Mod, Pkt) -> decode(Mod:id(), Mod, Pkt). -%% If we're a relay application then just extract the avp's without -%% any decoding of their data since we don't know the application in -%% question. +%% decode/3 + +%% Relay application: just extract the avp's without any decoding of +%% their data since we don't know the application in question. decode(?APP_ID_RELAY, _, #diameter_packet{} = Pkt) -> case collect_avps(Pkt) of {E, As} -> @@ -259,34 +364,36 @@ decode(_, Mod, #diameter_packet{header = Hdr} = Pkt) -> decode_avps(MsgName, Mod, Pkt, collect_avps(Pkt)); decode(Id, Mod, Bin) - when is_bitstring(Bin) -> + when is_binary(Bin) -> decode(Id, Mod, #diameter_packet{header = decode_header(Bin), bin = Bin}). +%% decode_avps/4 + decode_avps(MsgName, Mod, Pkt, {E, Avps}) -> - ?LOG(invalid, Pkt#diameter_packet.bin), + ?LOG(invalid_avp_length, Pkt#diameter_packet.header), #diameter_packet{errors = Failed} = P = decode_avps(MsgName, Mod, Pkt, Avps), P#diameter_packet{errors = [E | Failed]}; -decode_avps('', Mod, Pkt, Avps) -> %% unknown message ... - ?LOG(unknown, {Mod, Pkt#diameter_packet.header}), +decode_avps('', _, Pkt, Avps) -> %% unknown message ... + ?LOG(unknown_message, Pkt#diameter_packet.header), Pkt#diameter_packet{avps = lists:reverse(Avps), errors = [3001]}; %% DIAMETER_COMMAND_UNSUPPORTED %% msg = undefined identifies this case. decode_avps(MsgName, Mod, Pkt, Avps) -> %% ... or not - {Rec, As, Failed} = Mod:decode_avps(MsgName, Avps), - ?LOGC([] /= Failed, failed, {Mod, Failed}), + {Rec, As, Errors} = Mod:decode_avps(MsgName, Avps), + ?LOGC([] /= Errors, decode_errors, Pkt#diameter_packet.header), Pkt#diameter_packet{msg = Rec, - errors = Failed, + errors = Errors, avps = As}. %%% --------------------------------------------------------------------------- %%% # decode_header/1 %%% --------------------------------------------------------------------------- --spec decode_header(bitstring()) +-spec decode_header(binary()) -> #diameter_header{} | false. @@ -297,7 +404,7 @@ decode_header(<<Version:8, ApplicationId:32, HopByHopId:32, EndToEndId:32, - _/bitstring>>) -> + _/binary>>) -> <<R:1, P:1, E:1, T:1, _:4>> = CmdFlags, %% 3588 (ch 3) says that reserved bits MUST be set to 0 and ignored @@ -356,6 +463,9 @@ sequence_numbers(#diameter_packet{bin = Bin}) sequence_numbers(#diameter_packet{header = #diameter_header{} = H}) -> sequence_numbers(H); +sequence_numbers(#diameter_packet{msg = [#diameter_header{} = H | _]}) -> + sequence_numbers(H); + sequence_numbers(#diameter_header{hop_by_hop_id = H, end_to_end_id = E}) -> {H,E}; @@ -410,7 +520,7 @@ msg_id(#diameter_header{application_id = A, is_request = R}) -> {A, C, if R -> 1; true -> 0 end}; -msg_id(<<_:32, Rbit:1, _:7, CmdCode:24, ApplId:32, _/bitstring>>) -> +msg_id(<<_:32, Rbit:1, _:7, CmdCode:24, ApplId:32, _/binary>>) -> {ApplId, CmdCode, Rbit}. %%% --------------------------------------------------------------------------- @@ -421,17 +531,18 @@ msg_id(<<_:32, Rbit:1, _:7, CmdCode:24, ApplId:32, _/bitstring>>) -> %% order in the binary. Note also that grouped avp's aren't unraveled, %% only those at the top level. --spec collect_avps(#diameter_packet{} | bitstring()) +-spec collect_avps(#diameter_packet{} | binary()) -> [Avp] | {Error, [Avp]} when Avp :: #diameter_avp{}, Error :: {5014, #diameter_avp{}}. collect_avps(#diameter_packet{bin = Bin}) -> - <<_:20/binary, Avps/bitstring>> = Bin, + <<_:20/binary, Avps/binary>> = Bin, collect_avps(Avps); -collect_avps(Bin) -> +collect_avps(Bin) + when is_binary(Bin) -> collect_avps(Bin, 0, []). collect_avps(<<>>, _, Acc) -> @@ -461,7 +572,9 @@ collect_avps(Bin, N, Acc) -> split_avp(Bin) -> {Code, V, M, P, Len, HdrLen} = split_head(Bin), - {Data, B} = split_data(Bin, HdrLen, Len - HdrLen), + + <<_:HdrLen/binary, Rest/binary>> = Bin, + {Data, B} = split_data(Rest, Len - HdrLen), {B, #diameter_avp{code = Code, vendor_id = V, @@ -471,14 +584,16 @@ split_avp(Bin) -> %% split_head/1 -split_head(<<Code:32, 1:1, M:1, P:1, _:5, Len:24, V:32, _/bitstring>>) -> +split_head(<<Code:32, 1:1, M:1, P:1, _:5, Len:24, V:32, _/binary>>) -> {Code, V, M, P, Len, 12}; -split_head(<<Code:32, 0:1, M:1, P:1, _:5, Len:24, _/bitstring>>) -> +split_head(<<Code:32, 0:1, M:1, P:1, _:5, Len:24, _/binary>>) -> {Code, undefined, M, P, Len, 8}; +%% Header is truncated. split_head(Bin) -> ?THROW({5014, #diameter_avp{data = Bin}}). +%% Note that pack_avp/1 will pad this at encode if sent in a Failed-AVP. %% 3588: %% @@ -508,54 +623,59 @@ split_head(Bin) -> %% AVP header with zero up to the minimum AVP header length. %% %% The underlined clause must be in error since (1) a header less than -%% the minimum value mean we don't know the identity of the AVP and +%% the minimum value mean we might not know the identity of the AVP and %% (2) the last sentence covers this case. %% split_data/3 -split_data(Bin, HdrLen, Len) - when 0 =< Len -> - split_data(Bin, HdrLen, Len, (4 - (Len rem 4)) rem 4); - -split_data(_, _, _) -> - invalid_avp_length(). +split_data(Bin, Len) -> + Pad = (4 - (Len rem 4)) rem 4, -%% split_data/4 + %% Len might be negative here, but that ensures the failure of the + %% binary match. -split_data(Bin, HdrLen, Len, Pad) -> - <<_:HdrLen/binary, T/bitstring>> = Bin, - case T of - <<Data:Len/binary, _:Pad/binary, Rest/bitstring>> -> + case Bin of + <<Data:Len/binary, _:Pad/binary, Rest/binary>> -> {Data, Rest}; _ -> - invalid_avp_length() + %% Header length points past the end of the message, or + %% doesn't span the header. As stated in the 6733 text + %% above, it's sufficient to return a zero-filled minimal + %% payload if this is a request. Do this (in cases that we + %% know the type) by inducing a decode failure and letting + %% the dictionary's decode (in diameter_gen) deal with it. + %% + %% Note that the extra bit can only occur in the trailing + %% AVP of a message or Grouped AVP, since a faulty AVP + %% Length is otherwise indistinguishable from a correct + %% one here, since we don't know the types of the AVPs + %% being extracted. + {<<0:1, Bin/binary>>, <<>>} end. -%% invalid_avp_length/0 -%% -%% AVP Length doesn't mesh with payload. Induce a decode error by -%% returning a payload that no valid Diameter type can have. This is -%% so that a known AVP will result in 5014 error with a zero'd -%% payload. Here we simply don't know how to construct this payload. -%% (Yes, this solution is an afterthought.) - -invalid_avp_length() -> - {<<0:1>>, <<>>}. - %%% --------------------------------------------------------------------------- %%% # pack_avp/1 %%% --------------------------------------------------------------------------- %% The normal case here is data as an #diameter_avp{} list or an %% iolist, which are the cases that generated codec modules use. The -%% other case is as a convenience in the relay case in which the +%% other cases are a convenience in the relay case in which the %% dictionary doesn't know about specific AVP's. -%% Grouped AVP whose components need packing ... -pack_avp(#diameter_avp{data = [#diameter_avp{} | _] = Avps} = A) -> - pack_avp(A#diameter_avp{data = encode_avps(Avps)}); +%% Decoded Grouped AVP with decoded components: ignore components +%% since they're already encoded in the Grouped AVP. +pack_avp([#diameter_avp{} = Grouped | _Components]) -> + pack_avp(Grouped); + +%% Grouped AVP whose components need packing. It's intentional that +%% this isn't equivalent to [Grouped | Components]: here the +%% components need to be encoded before wrapping with the Grouped AVP, +%% and the list is flat, nesting being accomplished in the data +%% fields. +pack_avp(#diameter_avp{data = [#diameter_avp{} | _] = Components} = Grouped) -> + pack_avp(Grouped#diameter_avp{data = encode_avps(Components)}); -%% ... data as a type/value tuple ... +%% Data as a type/value tuple ... pack_avp(#diameter_avp{data = {Type, Value}} = A) when is_atom(Type) -> pack_avp(A#diameter_avp{data = diameter_types:Type(encode, Value)}); @@ -573,17 +693,23 @@ pack_avp(#diameter_avp{data = {Dict, Name, Value}} = A) -> {Name, Type} = Dict:avp_name(Code, Vid), pack_avp(A#diameter_avp{data = {Hdr, {Type, Value}}}); -pack_avp(#diameter_avp{code = undefined, data = Bin}) - when is_binary(Bin) -> +%% ... with a truncated header ... +pack_avp(#diameter_avp{code = undefined, data = B}) + when is_binary(B) -> %% Reset the AVP Length of an AVP Header resulting from a 5014 %% error. The RFC doesn't explicitly say to do this but the %% receiver can't correctly extract this and following AVP's %% without a correct length. On the downside, the header doesn't %% reveal if the received header has been padded. - Pad = 8*header_length(Bin) - bit_size(Bin), - Len = size(<<H:5/binary, _:24, T/binary>> = <<Bin/bitstring, 0:Pad>>), + Pad = 8*header_length(B) - bit_size(B), + Len = size(<<H:5/binary, _:24, T/binary>> = <<B/binary, 0:Pad>>), <<H/binary, Len:24, T/binary>>; +%% ... when ignoring errors in Failed-AVP ... +%% ... during a relay encode ... +pack_avp(#diameter_avp{data = <<0:1, B/binary>>} = A) -> + pack_avp(A#diameter_avp{data = B}); + %% ... or as an iolist. pack_avp(#diameter_avp{code = Code, vendor_id = V, |