aboutsummaryrefslogtreecommitdiffstats
path: root/lib/diameter/test/diameter_gen_sctp_SUITE.erl
blob: 2a2f75589219fdf1a5134e44004453b6ef8e0df6 (plain) (blame)
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
%%
%% %CopyrightBegin%
%%
%% 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/.
%%
%% 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%
%%

%%
%% Some gen_sctp-specific tests demonstrating problems that were
%% encountered during diameter development but have nothing
%% specifically to do with diameter. At least one of them can cause
%% diameter_transport_SUITE testcases to fail.
%%

-module(diameter_gen_sctp_SUITE).

-export([suite/0,
         all/0,
         init_per_suite/1,
         end_per_suite/1]).

%% testcases
-export([send_not_from_controlling_process/1,
         send_from_multiple_clients/1, send_from_multiple_clients/0,
         receive_what_was_sent/1]).

-include_lib("kernel/include/inet_sctp.hrl").

%% Message from gen_sctp are of this form.
-define(SCTP(Sock, Data), {sctp, Sock, _, _, Data}).

%% Open sockets on the loopback address.
-define(ADDR, {127,0,0,1}).

%% Snooze, nap, siesta.
-define(SLEEP(T), receive after T -> ok end).

%% An indescribably long number of milliseconds after which everthing
%% that should have happened has.
-define(FOREVER, 2000).

%% The first byte in each message we send as a simple guard against
%% not receiving what was sent.
-define(MAGIC, 42).

%% ===========================================================================

suite() ->
    [{timetrap, {seconds, 10}}].

all() ->
    [send_not_from_controlling_process,
     send_from_multiple_clients,
     receive_what_was_sent].

init_per_suite(Config) ->
    case gen_sctp:open() of
        {ok, Sock} ->
            gen_sctp:close(Sock),
            Config;
        {error, E} when E == eprotonosupport;
                        E == esocktnosupport ->
            {skip, no_sctp}
    end.

end_per_suite(_Config) ->
    ok.

%% ===========================================================================

%% send_not_from_controlling_process/1
%%
%% This testcase failing shows gen_sctp:send/4 hanging when called
%% outside the controlling process of the socket in question.

send_not_from_controlling_process(_) ->
    Pids = send_not_from_controlling_process(),
    ?SLEEP(?FOREVER),
    try
        [] = [{P,I} || P <- Pids, I <- [process_info(P)], I /= undefined]
    after
        lists:foreach(fun(P) -> exit(P, kill) end, Pids)
    end.

%% send_not_from_controlling_process/0
%%
%% Returns the pids of three spawned processes: a listening process, a
%% connecting process and a sending process.
%%
%% The expected behaviour is that all three processes exit:
%%
%% - The listening process exits upon receiving an SCTP message
%%   sent by the sending process.
%% - The connecting process exits upon listening process exit.
%% - The sending process exits upon gen_sctp:send/4 return.
%%
%% The observed behaviour is that all three processes remain alive
%% indefinitely:
%%
%% - The listening process never receives the SCTP message sent
%%   by the sending process.
%% - The connecting process has an inet_reply message in its mailbox
%%   as a consequence of the call to gen_sctp:send/4 call from the
%%   sending process.
%% - The call to gen_sctp:send/4 in the sending process doesn't return,
%%   hanging in prim_inet:getopts/2.

send_not_from_controlling_process() ->
    FPid = self(),
    {L, MRef} = spawn_monitor(fun() -> listen(FPid) end),
    receive
        {?MODULE, C, S} ->
            demonitor(MRef, [flush]),
            [L,C,S];
        {'DOWN', MRef, process, _, _} = T ->
            error(T)
    end.

%% listen/1

listen(FPid) ->
    {ok, Sock} = open(),
    ok = gen_sctp:listen(Sock, true),
    {ok, PortNr} = inet:port(Sock),
    LPid = self(),
    spawn(fun() -> connect1(PortNr, FPid, LPid) end), %% connecting process
    Id = assoc(Sock),
    recv(Sock, Id).

%% connect1/3

connect1(PortNr, FPid, LPid) ->
    {ok, Sock} = open(),
    ok = gen_sctp:connect_init(Sock, ?ADDR, PortNr, []),
    Id = assoc(Sock),
    FPid ! {?MODULE,
            self(),
            spawn(fun() -> send(Sock, Id) end)}, %% sending process
    MRef = monitor(process, LPid),
    down(MRef).  %% Waits with this as current_function.

%% down/1

down(MRef) ->
    receive {'DOWN', MRef, process, _, Reason} -> Reason end.

%% send/2

send(Sock, Id) ->
    ok = gen_sctp:send(Sock, Id, 0, <<0:32>>).

%% ===========================================================================

%% send_from_multiple_clients/0
%%
%% Demonstrates sluggish delivery of messages.

send_from_multiple_clients() ->
    [{timetrap, {seconds, 60}}].

send_from_multiple_clients(_) ->
    {S, Rs} = T = send_from_multiple_clients(8, 1024),
    Max = ?FOREVER*1000,
    {false, [], _} = {Max < S,
                      Rs -- [OI || {O,_} = OI <- Rs, is_integer(O)],
                      T}.

%% send_from_multiple_clients/2
%%
%% Opens a listening socket and then spawns a specified number of
%% processes, each of which connects to the listening socket. Each
%% connecting process then sends a message, whose size in bytes is
%% passed as an argument, the listening process sends a reply
%% containing the time at which the message was received, and the
%% connecting process then exits upon reception of this reply.
%%
%% Returns the elapsed time for all connecting process to exit
%% together with a list of exit reasons for the connecting processes.
%% In the successful case a connecting process exits with the
%% outbound/inbound transit times for the sent/received message as
%% reason.
%%
%% The observed behaviour is that some outbound messages (that is,
%% from a connecting process to the listening process) can take an
%% unexpectedly long time to complete their journey. The more
%% connecting processes, the longer the possible delay it seems.
%%
%% eg. (With F = fun send_from_multiple_clients/2.)
%%
%%     5> F(2, 1024).
%%     {875,[{128,116},{113,139}]}
%%     6> F(4, 1024).
%%     {2995290,[{2994022,250},{2994071,80},{200,130},{211,113}]}
%%     7> F(8, 1024).
%%     {8997461,[{8996161,116},
%%               {2996471,86},
%%               {2996278,116},
%%               {2996360,95},
%%               {246,112},
%%               {213,159},
%%               {373,173},
%%               {376,118}]}
%%     8> F(8, 1024).
%%     {21001891,[{20999968,128},
%%                {8997891,172},
%%                {8997927,91},
%%                {2995716,164},
%%                {2995860,87},
%%                {134,100},
%%                {117,98},
%%                {149,125}]}
%%
%% This turns out to have been due to SCTP resends as a consequence of
%% the listener having an insufficient recbuf. Increasing the size
%% solves the problem.
%%

send_from_multiple_clients(N, Sz)
  when is_integer(N), 0 < N, is_integer(Sz), 0 < Sz ->
    timer:tc(fun listen/2, [N, <<?MAGIC, 0:Sz/unit:8>>]).

%% listen/2

listen(N, Bin) ->
    {ok, Sock} = open(),
    ok = gen_sctp:listen(Sock, true),
    {ok, PortNr} = inet:port(Sock),

    %% Spawn a middleman that in turn spawns N connecting processes,
    %% collects a list of exit reasons and then exits with the list as
    %% reason. loop/3 returns when we receive this list from the
    %% middleman's 'DOWN'.

    Self = self(),
    Fun = fun() -> exit(connect2(Self, PortNr, Bin)) end,
    {_, MRef} = spawn_monitor(fun() -> exit(fold(N, Fun)) end),
    loop(Sock, MRef, Bin).

%% fold/2
%%
%% Spawn N processes and collect their exit reasons in a list.

fold(N, Fun) ->
    start(N, Fun),
    acc(N, []).

start(0, _) ->
    ok;
start(N, Fun) ->
    spawn_monitor(Fun),
    start(N-1, Fun).

acc(0, Acc) ->
    Acc;
acc(N, Acc) ->
    receive
        {'DOWN', _MRef, process, _, RC} ->
            acc(N-1, [RC | Acc])
    end.

%% loop/3

loop(Sock, MRef, Bin) ->
    receive
        ?SCTP(Sock, {[#sctp_sndrcvinfo{assoc_id = Id}], B})
          when is_binary(B) ->
            Sz = size(Bin),
            {Sz, Bin} = {size(B), B},  %% assert
            ok = send(Sock, Id, mark(Bin)),
            loop(Sock, MRef, Bin);
        ?SCTP(Sock, _) ->
            loop(Sock, MRef, Bin);
        {'DOWN', MRef, process, _, Reason} ->
            Reason
    end.

%% connect2/3

connect2(Pid, PortNr, Bin) ->
    monitor(process, Pid),

    {ok, Sock} = open(),
    ok = gen_sctp:connect_init(Sock, ?ADDR, PortNr, []),
    Id = assoc(Sock),

    %% T1 = time before send
    %% T2 = time after listening process received our message
    %% T3 = time after reply is received

    T1 = diameter_util:timestamp(),
    ok = send(Sock, Id, Bin),
    T2 = unmark(recv(Sock, Id)),
    T3 = diameter_util:timestamp(),
    {diameter_lib:micro_diff(T2, T1),  %% Outbound
     diameter_lib:micro_diff(T3, T2)}. %% Inbound

%% recv/2

recv(Sock, Id) ->
    receive
        ?SCTP(Sock, {[#sctp_sndrcvinfo{assoc_id = I}], Bin})
          when is_binary(Bin) ->
            Id = I,   %% assert
            Bin;
        ?SCTP(S, _) ->
            Sock = S, %% assert
            recv(Sock, Id);
        T ->
            exit(T)
    end.

%% send/3

send(Sock, Id, Bin) ->
    gen_sctp:send(Sock, Id, 0, Bin).

%% mark/1

mark(Bin) ->
    Info = term_to_binary(diameter_util:timestamp()),
    <<Info/binary, Bin/binary>>.

%% unmark/1

unmark(Bin) ->
    {_,_,_} = binary_to_term(Bin).

%% ===========================================================================

%% receive_what_was_sent/1
%%
%% Demonstrates reception of a message that differs from that sent.

receive_what_was_sent(_Config) ->
    send_from_multiple_clients(1, 1024*32).  %% fails

%% ===========================================================================

%% open/0

open() ->
    open([]).

%% open/1

open(Opts) ->
    gen_sctp:open([{ip, ?ADDR}, {port, 0}, {active, true}, binary,
                   {recbuf, 1 bsl 16}, {sndbuf, 1 bsl 16}
                   | Opts]).

%% assoc/1

assoc(Sock) ->
    receive
        ?SCTP(Sock, {[], #sctp_assoc_change{state = S,
                                            assoc_id = Id}}) ->
            comm_up = S,  %% assert
            Id
    end.