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-rw-r--r--lib/diameter/src/base/diameter_codec.erl175
1 files changed, 139 insertions, 36 deletions
diff --git a/lib/diameter/src/base/diameter_codec.erl b/lib/diameter/src/base/diameter_codec.erl
index e446a0209c..6c0e73de36 100644
--- a/lib/diameter/src/base/diameter_codec.erl
+++ b/lib/diameter/src/base/diameter_codec.erl
@@ -38,6 +38,10 @@
-define(MASK(N,I), ((I) band (1 bsl (N)))).
+-type u32() :: 0..16#FFFFFFFF.
+-type u24() :: 0..16#FFFFFF.
+-type u1() :: 0..1.
+
%% 0 1 2 3
%% 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
%% +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@@ -55,9 +59,13 @@
%% +-+-+-+-+-+-+-+-+-+-+-+-+-
%%% ---------------------------------------------------------------------------
-%%% # encode/[2-4]
+%%% # encode/2
%%% ---------------------------------------------------------------------------
+-spec encode(module(), Msg :: term())
+ -> #diameter_packet{}
+ | no_return().
+
encode(Mod, #diameter_packet{} = Pkt) ->
try
e(Mod, Pkt)
@@ -217,6 +225,9 @@ rec2msg(Mod, Rec) ->
%% Unsuccessfully decoded AVPs will be placed in #diameter_packet.errors.
+-spec decode(module(), #diameter_packet{} | bitstring())
+ -> #diameter_packet{}.
+
decode(Mod, Pkt) ->
decode(Mod:id(), Mod, Pkt).
@@ -225,9 +236,9 @@ decode(Mod, Pkt) ->
%% question.
decode(?APP_ID_RELAY, _, #diameter_packet{} = Pkt) ->
case collect_avps(Pkt) of
- {Bs, As} ->
+ {E, As} ->
Pkt#diameter_packet{avps = As,
- errors = [Bs]};
+ errors = [E]};
As ->
Pkt#diameter_packet{avps = As}
end;
@@ -251,12 +262,12 @@ decode(Id, Mod, Bin)
when is_bitstring(Bin) ->
decode(Id, Mod, #diameter_packet{header = decode_header(Bin), bin = Bin}).
-decode_avps(MsgName, Mod, Pkt, {Bs, Avps}) -> %% invalid avp bits ...
+decode_avps(MsgName, Mod, Pkt, {E, Avps}) ->
?LOG(invalid, Pkt#diameter_packet.bin),
#diameter_packet{errors = Failed}
= P
= decode_avps(MsgName, Mod, Pkt, Avps),
- P#diameter_packet{errors = [Bs | Failed]};
+ P#diameter_packet{errors = [E | Failed]};
decode_avps('', Mod, Pkt, Avps) -> %% unknown message ...
?LOG(unknown, {Mod, Pkt#diameter_packet.header}),
@@ -275,6 +286,10 @@ decode_avps(MsgName, Mod, Pkt, Avps) -> %% ... or not
%%% # decode_header/1
%%% ---------------------------------------------------------------------------
+-spec decode_header(bitstring())
+ -> #diameter_header{}
+ | false.
+
decode_header(<<Version:8,
MsgLength:24,
CmdFlags:1/binary,
@@ -324,6 +339,13 @@ decode_header(_) ->
%% wraparound counter. The 8-bit counter is incremented each time the
%% system is restarted.
+-spec sequence_numbers(#diameter_packet{}
+ | #diameter_header{}
+ | binary()
+ | Seq)
+ -> Seq
+ when Seq :: {HopByHopId :: u32(), EndToEndId :: u32()}.
+
sequence_numbers({_,_} = T) ->
T;
@@ -345,6 +367,9 @@ sequence_numbers(<<_:12/binary, H:32, E:32, _/binary>>) ->
%%% # hop_by_hop_id/2
%%% ---------------------------------------------------------------------------
+-spec hop_by_hop_id(u32(), binary())
+ -> binary().
+
hop_by_hop_id(Id, <<H:12/binary, _:32, T/binary>>) ->
<<H/binary, Id:32, T/binary>>.
@@ -352,6 +377,10 @@ hop_by_hop_id(Id, <<H:12/binary, _:32, T/binary>>) ->
%%% # msg_name/2
%%% ---------------------------------------------------------------------------
+-spec msg_name(module(), #diameter_header{})
+ -> atom()
+ | {ApplicationId :: u32(), CommandCode :: u24(), Rbit :: u1()}.
+
msg_name(Dict0, #diameter_header{application_id = ?APP_ID_COMMON,
cmd_code = C,
is_request = R}) ->
@@ -367,6 +396,9 @@ msg_name(_, Hdr) ->
%%% # msg_id/1
%%% ---------------------------------------------------------------------------
+-spec msg_id(#diameter_packet{} | #diameter_header{})
+ -> {ApplicationId :: u32(), CommandCode :: u24(), Rbit :: u1()}.
+
msg_id(#diameter_packet{msg = [#diameter_header{} = Hdr | _]}) ->
msg_id(Hdr);
@@ -389,6 +421,12 @@ 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())
+ -> [Avp]
+ | {Error, [Avp]}
+ when Avp :: #diameter_avp{},
+ Error :: {5014, #diameter_avp{}}.
+
collect_avps(#diameter_packet{bin = Bin}) ->
<<_:20/binary, Avps/bitstring>> = Bin,
collect_avps(Avps);
@@ -403,8 +441,8 @@ collect_avps(Bin, N, Acc) ->
{Rest, AVP} ->
collect_avps(Rest, N+1, [AVP#diameter_avp{index = N} | Acc])
catch
- ?FAILURE(_) ->
- {Bin, Acc}
+ ?FAILURE(Error) ->
+ {Error, Acc}
end.
%% 0 1 2 3
@@ -422,42 +460,87 @@ collect_avps(Bin, N, Acc) ->
%% split_avp/1
split_avp(Bin) ->
- 8 =< size(Bin) orelse ?THROW(truncated_header),
+ {Code, V, M, P, Len, HdrLen} = split_head(Bin),
+ {Data, B} = split_data(Bin, HdrLen, Len - HdrLen),
- <<Code:32, Flags:1/binary, Length:24, Rest/bitstring>>
- = Bin,
+ {B, #diameter_avp{code = Code,
+ vendor_id = V,
+ is_mandatory = 1 == M,
+ need_encryption = 1 == P,
+ data = Data}}.
- DataSize = Length - 8, % size(Code+Flags+Length) = 8 octets
- PadSize = (4 - (DataSize rem 4)) rem 4,
+%% split_head/1
- DataSize + PadSize =< size(Rest)
- orelse ?THROW(truncated_data),
+split_head(<<Code:32, 1:1, M:1, P:1, _:5, Len:24, V:32, _/bitstring>>) ->
+ {Code, V, M, P, Len, 12};
- <<Data:DataSize/binary, _:PadSize/binary, R/bitstring>>
- = Rest,
- <<Vbit:1, Mbit:1, Pbit:1, _Reserved:5>>
- = Flags,
+split_head(<<Code:32, 0:1, M:1, P:1, _:5, Len:24, _/bitstring>>) ->
+ {Code, undefined, M, P, Len, 8};
- 0 == Vbit orelse 4 =< size(Data)
- orelse ?THROW(truncated_vendor_id),
+split_head(Bin) ->
+ ?THROW({5014, #diameter_avp{data = Bin}}).
+
+%% 3588:
+%%
+%% DIAMETER_INVALID_AVP_LENGTH 5014
+%% The request contained an AVP with an invalid length. A Diameter
+%% message indicating this error MUST include the offending AVPs
+%% within a Failed-AVP AVP.
- {Vid, D} = vid(Vbit, Data),
- {R, #diameter_avp{code = Code,
- vendor_id = Vid,
- is_mandatory = 1 == Mbit,
- need_encryption = 1 == Pbit,
- data = D}}.
+%% 6733:
+%%
+%% DIAMETER_INVALID_AVP_LENGTH 5014
+%%
+%% The request contained an AVP with an invalid length. A Diameter
+%% message indicating this error MUST include the offending AVPs
+%% within a Failed-AVP AVP. In cases where the erroneous AVP length
+%% value exceeds the message length or is less than the minimum AVP
+%% ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+%% header length, it is sufficient to include the offending AVP
+%% ^^^^^^^^^^^^^
+%% header and a zero filled payload of the minimum required length
+%% for the payloads data type. If the AVP is a Grouped AVP, the
+%% Grouped AVP header with an empty payload would be sufficient to
+%% indicate the offending AVP. In the case where the offending AVP
+%% header cannot be fully decoded when the AVP length is less than
+%% the minimum AVP header length, it is sufficient to include an
+%% offending AVP header that is formulated by padding the incomplete
+%% 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
+%% (2) the last sentence covers this case.
-%% The RFC is a little misleading when stating that OctetString is
-%% padded to a 32-bit boundary while other types align naturally. All
-%% other types are already multiples of 32 bits so there's no need to
-%% distinguish between types here. Any invalid lengths will result in
-%% decode error in diameter_types.
+%% split_data/3
-vid(1, <<Vid:32, Data/bitstring>>) ->
- {Vid, Data};
-vid(0, Data) ->
- {undefined, Data}.
+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/4
+
+split_data(Bin, HdrLen, Len, Pad) ->
+ <<_:HdrLen/binary, T/bitstring>> = Bin,
+ case T of
+ <<Data:Len/binary, _:Pad/binary, Rest/bitstring>> ->
+ {Data, Rest};
+ _ ->
+ invalid_avp_length()
+ 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
@@ -472,20 +555,35 @@ vid(0, Data) ->
pack_avp(#diameter_avp{data = [#diameter_avp{} | _] = Avps} = A) ->
pack_avp(A#diameter_avp{data = encode_avps(Avps)});
-%% ... data as a type/value tuple, possibly with header data, ...
+%% ... 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)});
+
+%% ... with a header in various forms ...
pack_avp(#diameter_avp{data = {{_,_,_} = T, {Type, Value}}}) ->
pack_avp(T, iolist_to_binary(diameter_types:Type(encode, Value)));
+
pack_avp(#diameter_avp{data = {{_,_,_} = T, Bin}})
when is_binary(Bin) ->
pack_avp(T, Bin);
+
pack_avp(#diameter_avp{data = {Dict, Name, Value}} = A) ->
{Code, _Flags, Vid} = Hdr = Dict:avp_header(Name),
{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) ->
+ %% 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>>),
+ <<H/binary, Len:24, T/binary>>;
+
%% ... or as an iolist.
pack_avp(#diameter_avp{code = Code,
vendor_id = V,
@@ -497,6 +595,11 @@ pack_avp(#diameter_avp{code = Code,
{P, 2#00100000}]),
pack_avp({Code, Flags, V}, iolist_to_binary(Data)).
+header_length(<<_:32, 1:1, _/bitstring>>) ->
+ 12;
+header_length(_) ->
+ 8.
+
flag_avp({true, B}, F) ->
F bor B;
flag_avp({false, _}, F) ->