aboutsummaryrefslogblamecommitdiffstats
path: root/lib/diameter/include/diameter_gen.hrl
blob: 4c91954a21f7e554f220a87f55afbce2dfd2b482 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431














































































































































































































































































































































































































































                                                                               
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2010-2011. 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/.
%%
%% 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.
%%
%% %CopyrightEnd%
%%

%%
%% This file contains code that's included by encode/decode modules
%% generated by diameter_codegen.erl. This code does most of the work, the
%% generated code being kept simple.
%%

-define(THROW(T), throw({?MODULE, T})).

%%% ---------------------------------------------------------------------------
%%% # encode_avps/3
%%%
%%% Returns: binary()
%%% ---------------------------------------------------------------------------

encode_avps(Name, Vals)
  when is_list(Vals) ->
    encode_avps(Name, '#set-'(Vals, newrec(Name)));

encode_avps(Name, Rec) ->
    try
        list_to_binary(encode(Name, Rec))
    catch
        throw: {?MODULE, Reason} ->
            diameter_dbg:log({encode, error},
                             ?MODULE,
                             ?LINE,
                             {Reason, Name, Rec}),
            erlang:error(list_to_tuple(Reason ++ [Name, Rec, ?MODULE]));
        error: Reason ->
            Stack = erlang:get_stacktrace(),
            diameter_dbg:log({encode, failure},
                             ?MODULE,
                             ?LINE,
                             {Reason, Name, Rec, Stack}),
            erlang:error({encode_failure, Reason, Name, Rec, ?MODULE, Stack})
    end.

%% encode/2

encode(Name, Rec) ->
    lists:flatmap(fun(A) -> encode(Name, A, '#get-'(A, Rec)) end,
                  '#info-'(element(1, Rec), fields)).

%% encode/3

encode(Name, AvpName, Values) ->
    e(Name, AvpName, avp_arity(Name, AvpName), Values).

%% e/4

e(_, AvpName, 1, undefined) ->
    ?THROW([mandatory_avp_missing, AvpName]);

e(Name, AvpName, 1, Value) ->
    e(Name, AvpName, [Value]);

e(_, _, {0,_}, []) ->
    [];

e(_, AvpName, _, T)
  when not is_list(T) ->
    ?THROW([repeated_avp_as_non_list, AvpName, T]);

e(_, AvpName, {Min, _}, L)
  when length(L) < Min ->
    ?THROW([repeated_avp_insufficient_arity, AvpName, Min, L]);

e(_, AvpName, {_, Max}, L)
  when Max < length(L) ->
    ?THROW([repeated_avp_excessive_arity, AvpName, Max, L]);

e(Name, AvpName, _, Values) ->
    e(Name, AvpName, Values).

%% e/3

e(Name, 'AVP', Values) ->
    [pack_AVP(Name, A) || A <- Values];

e(_, AvpName, Values) ->
    e(AvpName, Values).

%% e/2

e(AvpName, Values) ->
    H = avp_header(AvpName),
    [diameter_codec:pack_avp(H, avp(encode, V, AvpName)) || V <- Values].

%% pack_AVP/2

%% No value: assume AVP data is already encoded. The normal case will
%% be when this is passed back from #diameter_packet.errors as a
%% consequence of a failed decode. Any AVP can be encoded this way
%% however, which side-steps any arity checks for known AVP's and
%% could potentially encode something unfortunate.
pack_AVP(_, #diameter_avp{value = undefined} = A) ->
    diameter_codec:pack_avp(A);

%% Missing name for value encode.
pack_AVP(_, #diameter_avp{name = N, value = V})
  when N == undefined;
       N == 'AVP' ->
    ?THROW([value_with_nameless_avp, N, V]);

%% Or not. Ensure that 'AVP' is the appropriate field. Note that if we
%% don't know this AVP at all then the encode will fail.
pack_AVP(Name, #diameter_avp{name = AvpName,
                             value = Data}) ->
    0 == avp_arity(Name, AvpName)
        orelse ?THROW([known_avp_as_AVP, Name, AvpName, Data]),
    e(AvpName, [Data]).

%%% ---------------------------------------------------------------------------
%%% # decode_avps/2
%%%
%%% Returns: {Rec, Avps, Failed}
%%%
%%%          Rec  = decoded message record
%%%          Avps = list of Avp
%%%          Failed = list of {ResultCode, #diameter_avp{}}
%%%
%%%          Avp = #diameter_avp{}    if type is not Grouped
%%%              | list of Avp        where first element has type Grouped
%%%                                   and following elements are its component
%%%                                   AVP's.
%%% ---------------------------------------------------------------------------

decode_avps(Name, Recs) ->
    d_rc(Name, lists:foldl(fun(T,A) -> decode(Name, T, A) end,
                           {[], {newrec(Name), []}},
                           Recs)).

newrec(Name) ->
    '#new-'(name2rec(Name)).

%% No errors so far: keep looking.
d_rc(Name, {Avps, {Rec, [] = Failed}}) ->
    try
        true = have_required_avps(Rec, Name),
        {Rec, Avps, Failed}
    catch
        throw: {?MODULE, {AvpName, Reason}} ->
            diameter_dbg:log({decode, error},
                             ?MODULE,
                             ?LINE,
                             {AvpName, Reason, Rec}),
            {Rec, Avps, [{5005, empty_avp(AvpName)}]}
    end;
%% 3588:
%%
%%   DIAMETER_MISSING_AVP               5005
%%      The request did not contain an AVP that is required by the Command
%%      Code definition.  If this value is sent in the Result-Code AVP, a
%%      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.

%% Or not. Only need to report the first error so look no further.
d_rc(_, {Avps, {Rec, Failed}}) ->
    {Rec, Avps, lists:reverse(Failed)}.

%% empty_avp/1

empty_avp(Name) ->
    {Code, Flags, VId} = avp_header(Name),
    {Name, Type} = avp_name(Code, VId),
    #diameter_avp{name = Name,
                  code = Code,
                  vendor_id = VId,
                  is_mandatory = 0 /= (Flags band 2#01000000),
                  need_encryption = 0 /= (Flags band 2#00100000),
                  data = empty_value(Name),
                  type = Type}.

%% have_required_avps/2

have_required_avps(Rec, Name) ->
    lists:foreach(fun(F) -> hra(Name, F, Rec) end,
                  '#info-'(element(1, Rec), fields)),
    true.

hra(Name, AvpName, Rec) ->
    Arity = avp_arity(Name, AvpName),
    hra(Arity, '#get-'(AvpName, Rec))
        orelse ?THROW({AvpName, {insufficient_arity, Arity}}).

%% Maximum arities have already been checked in building the record.

hra({Min, _}, L) ->
    Min =< length(L);
hra(N, V) ->
    N /= 1 orelse V /= undefined.

%% 3588, ch 7:
%%
%%   The Result-Code AVP describes the error that the Diameter node
%%   encountered in its processing.  In case there are multiple errors,
%%   the Diameter node MUST report only the first error it encountered
%%   (detected possibly in some implementation dependent order).  The
%%   specific errors that can be described by this AVP are described in
%%   the following section.

%% decode/3

decode(Name, #diameter_avp{code = Code, vendor_id = Vid} = Avp, Acc) ->
    decode(Name, avp_name(Code, Vid), Avp, Acc).

%% decode/4

%% Don't know this AVP: see if it can be packed in an 'AVP' field
%% undecoded, unless it's mandatory. Need to give Failed-AVP special
%% treatment since it'll contain any unrecognized mandatory AVP's.
decode(Name, 'AVP', #diameter_avp{is_mandatory = M} = Avp, {Avps, Acc}) ->
    {[Avp | Avps], if M, Name /= 'Failed-AVP' ->
                           unknown(Avp, Acc);
                      true ->
                           pack_AVP(Name, Avp, Acc)
                   end};
%% Note that the type field is 'undefined' in this case.

%% Or try to decode.
decode(Name, {AvpName, Type}, Avp, Acc) ->
    d(Name, Avp#diameter_avp{name = AvpName, type = Type}, Acc).

%% d/3

d(Name, Avp, {Avps, Acc}) ->
    #diameter_avp{name = AvpName,
                  data = Data}
        = Avp,

    try avp(decode, Data, AvpName) of
        V ->
            {H, A} = ungroup(V, Avp),
            {[H | Avps], pack_avp(Name, A, Acc)}
    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_dbg:log({decode, failure},
                             ?MODULE,
                             ?LINE,
                             {Reason, Avp, erlang:get_stacktrace()}),
            {Rec, Failed} = Acc,
            {[Avp|Avps], {Rec, [{rc(Reason), Avp} | Failed]}}
    end.

%% 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.
rc({'DIAMETER', RC, _}) ->
    RC;

%% 3588:
%%
%%   DIAMETER_INVALID_AVP_VALUE         5004
%%      The request contained an AVP with an invalid value in its data
%%      portion.  A Diameter message indicating this error MUST include
%%      the offending AVPs within a Failed-AVP AVP.
rc(_) ->
    5004.

%% ungroup/2
%%
%% Returns: {Avp, Dec}
%%
%%          Avp = #diameter_avp{}    if type is not Grouped
%%              | list of Avp        where first element has type Grouped
%%                                   and following elements are its component
%%                                   AVP's.
%%              = as for decode_avps/2
%%
%%          Dec = #diameter_avp{}, either Avp or its head in the list case.

%% The decoded value in the Grouped case is as returned by grouped_avp/3:
%% a record and a list of component AVP's.
ungroup(V, #diameter_avp{type = 'Grouped'} = Avp) ->
    {Rec, As} = V,
    A = Avp#diameter_avp{value = Rec},
    {[A|As], A};

%% Otherwise it's just a plain value.
ungroup(V, #diameter_avp{} = Avp) ->
    A = Avp#diameter_avp{value = V},
    {A, A}.

%% pack_avp/3

pack_avp(Name, #diameter_avp{name = AvpName} = Avp, Acc) ->
    pack_avp(Name, avp_arity(Name, AvpName), Avp, Acc).

%% pack_avp/4

pack_avp(Name, 0, Avp, Acc) ->
    pack_AVP(Name, Avp, Acc);

pack_avp(_, Arity, Avp, Acc) ->    
    pack(Arity, Avp#diameter_avp.name, Avp, Acc).

%% pack_AVP/3

pack_AVP(Name, Avp, Acc) ->
    case avp_arity(Name, 'AVP') of
        0 ->
            unknown(Avp, Acc);
        Arity ->
            pack(Arity, 'AVP', Avp, Acc)
    end.
    
%% 3588:
%%
%%   DIAMETER_AVP_UNSUPPORTED           5001
%%      The peer received a message that contained an AVP that is not
%%      recognized or supported and was marked with the Mandatory bit.  A
%%      Diameter message with this error MUST contain one or more Failed-
%%      AVP AVP containing the AVPs that caused the failure.
%%
%%   DIAMETER_AVP_NOT_ALLOWED           5008
%%      A message was received with an AVP that MUST NOT be present.  The
%%      Failed-AVP AVP MUST be included and contain a copy of the
%%      offending AVP.
%%
unknown(#diameter_avp{is_mandatory = B} = Avp, {Rec, Failed}) ->
    {Rec, [{if B -> 5001; true -> 5008 end, Avp} | Failed]}.

%% pack/4

pack(Arity, FieldName, Avp, {Rec, _} = Acc) ->
    pack('#get-'(FieldName, Rec), Arity, FieldName, Avp, Acc).

%% pack/5

pack(undefined, 1, FieldName, Avp, Acc) ->
    p(FieldName, fun(V) -> V end, Avp, Acc);

%% 3588:
%%
%%   DIAMETER_AVP_OCCURS_TOO_MANY_TIMES 5009
%%      A message was received that included an AVP that appeared more
%%      often than permitted in the message definition.  The Failed-AVP
%%      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).

%% p/4

p(F, Fun, Avp, {Rec, Failed}) ->
    {'#set-'({F, Fun(value(F, Avp))}, Rec), Failed}.

value('AVP', Avp) ->
    Avp;
value(_, Avp) ->
    Avp#diameter_avp.value.

%%% ---------------------------------------------------------------------------
%%% # grouped_avp/3
%%% ---------------------------------------------------------------------------

grouped_avp(decode, Name, Data) ->
    {Rec, Avps, []} = decode_avps(Name, diameter_codec:collect_avps(Data)),
    {Rec, Avps};
%% Note that a failed match here will result in 5004. Note that this is
%% the only AVP type that doesn't just return the decoded value, also
%% returning the list of component #diameter_avp{}'s.

grouped_avp(encode, Name, Data) ->
    encode_avps(Name, Data).

%%% ---------------------------------------------------------------------------
%%% # empty_group/1
%%% ---------------------------------------------------------------------------

empty_group(Name) ->
    list_to_binary(empty_body(Name)).

empty_body(Name) ->
    [z(F, avp_arity(Name, F)) || F <- '#info-'(name2rec(Name), fields)].

z(Name, 1) ->
    z(Name);
z(_, {0,_}) ->
    [];
z(Name, {Min, _}) ->
    lists:duplicate(Min, z(Name)).

z('AVP') ->
    <<0:64/integer>>;  %% minimal header
z(Name) ->
    Bin = diameter_codec:pack_avp(avp_header(Name), empty_value(Name)),
    << <<0>> || <<_>> <= Bin >>.

%%% ---------------------------------------------------------------------------
%%% # empty/1
%%% ---------------------------------------------------------------------------

empty(AvpName) ->
    avp(encode, zero, AvpName).