sunrpc/tst-udp-timeout.c

   1 /* Test timeout handling in the UDP client.
   2    Copyright (C) 2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <netinet/in.h>
  20 #include <rpc/clnt.h>
  21 #include <rpc/svc.h>
  22 #include <stdbool.h>
  23 #include <string.h>
  24 #include <support/check.h>
  25 #include <support/namespace.h>
  26 #include <support/test-driver.h>
  27 #include <support/xsocket.h>
  28 #include <support/xunistd.h>
  29 #include <sys/socket.h>
  30 #include <time.h>
  31 #include <unistd.h>
  32
  33 /* Test data serialization and deserialization.   */
  34
  35 struct test_query
  36 {
  37   uint32_t a;
  38   uint32_t b;
  39   uint32_t timeout_ms;
  40   uint32_t wait_for_seq;
  41   uint32_t garbage_packets;
  42 };
  43
  44 static bool_t
  45 xdr_test_query (XDR *xdrs, void *data, ...)
  46 {
  47   struct test_query *p = data;
  48   return xdr_uint32_t (xdrs, &p->a)
  49     && xdr_uint32_t (xdrs, &p->b)
  50     && xdr_uint32_t (xdrs, &p->timeout_ms)
  51     && xdr_uint32_t (xdrs, &p->wait_for_seq)
  52     && xdr_uint32_t (xdrs, &p->garbage_packets);
  53 }
  54
  55 struct test_response
  56 {
  57   uint32_t seq;
  58   uint32_t sum;
  59 };
  60
  61 static bool_t
  62 xdr_test_response (XDR *xdrs, void *data, ...)
  63 {
  64   struct test_response *p = data;
  65   return xdr_uint32_t (xdrs, &p->seq)
  66     && xdr_uint32_t (xdrs, &p->sum);
  67 }
  68
  69 /* Implementation of the test server.  */
  70
  71 enum
  72   {
  73     /* RPC parameters, chosen at random.  */
  74     PROGNUM = 15717,
  75     VERSNUM = 13689,
  76
  77     /* Main RPC operation.  */
  78     PROC_ADD = 1,
  79
  80     /* Reset the sequence number.  */
  81     PROC_RESET_SEQ,
  82
  83     /* Request process termination.  */
  84     PROC_EXIT,
  85
  86     /* Special exit status to mark successful processing.  */
  87     EXIT_MARKER = 55,
  88   };
  89
  90 static void
  91 server_dispatch (struct svc_req *request, SVCXPRT *transport)
  92 {
  93   /* Query sequence number.  */
  94   static uint32_t seq = 0;
  95   ++seq;
  96
  97   if (test_verbose)
  98     printf ("info: server_dispatch seq=%u rq_proc=%lu\n",
  99             seq, request->rq_proc);
 100
 101   switch (request->rq_proc)
 102     {
 103     case PROC_ADD:
 104       {
 105         struct test_query query;
 106         memset (&query, 0xc0, sizeof (query));
 107         TEST_VERIFY_EXIT
 108           (svc_getargs (transport, xdr_test_query,
 109                         (void *) &query));
 110
 111         if (test_verbose)
 112           printf ("  a=%u b=%u timeout_ms=%u wait_for_seq=%u"
 113                   " garbage_packets=%u\n",
 114                   query.a, query.b, query.timeout_ms, query.wait_for_seq,
 115                   query.garbage_packets);
 116
 117         if (seq < query.wait_for_seq)
 118           {
 119             /* No response at this point.  */
 120             if (test_verbose)
 121               printf ("  skipped response\n");
 122             break;
 123           }
 124
 125         if (query.garbage_packets > 0)
 126           {
 127             int per_packet_timeout;
 128             if (query.timeout_ms > 0)
 129               per_packet_timeout
 130                 = query.timeout_ms * 1000 / query.garbage_packets;
 131             else
 132               per_packet_timeout = 0;
 133
 134             char buf[20];
 135             memset (&buf, 0xc0, sizeof (buf));
 136             for (int i = 0; i < query.garbage_packets; ++i)
 137               {
 138                 /* 13 is relatively prime to 20 = sizeof (buf) + 1, so
 139                    the len variable will cover the entire interval
 140                    [0, 20] if query.garbage_packets is sufficiently
 141                    large.  */
 142                 size_t len = (i * 13 + 1) % (sizeof (buf) + 1);
 143                 TEST_VERIFY (sendto (transport->xp_sock,
 144                                      buf, len, MSG_NOSIGNAL,
 145                                      (struct sockaddr *) &transport->xp_raddr,
 146                                      transport->xp_addrlen) == len);
 147                 if (per_packet_timeout > 0)
 148                   usleep (per_packet_timeout);
 149               }
 150           }
 151         else if (query.timeout_ms > 0)
 152           usleep (query.timeout_ms * 1000);
 153
 154         struct test_response response =
 155           {
 156             .seq = seq,
 157             .sum = query.a + query.b,
 158           };
 159         TEST_VERIFY (svc_sendreply (transport, xdr_test_response,
 160                                     (void *) &response));
 161       }
 162       break;
 163
 164     case PROC_RESET_SEQ:
 165       seq = 0;
 166       TEST_VERIFY (svc_sendreply (transport, (xdrproc_t) xdr_void, NULL));
 167       break;
 168
 169     case PROC_EXIT:
 170       TEST_VERIFY (svc_sendreply (transport, (xdrproc_t) xdr_void, NULL));
 171       _exit (EXIT_MARKER);
 172       break;
 173
 174     default:
 175       FAIL_EXIT1 ("invalid rq_proc value: %lu", request->rq_proc);
 176       break;
 177     }
 178 }
 179
 180 /* Implementation of the test client.  */
 181
 182 static struct test_response
 183 test_call (CLIENT *clnt, int proc, struct test_query query,
 184            struct timeval timeout)
 185 {
 186   if (test_verbose)
 187     printf ("info: test_call proc=%d timeout=%lu.%06lu\n",
 188             proc, (unsigned long) timeout.tv_sec,
 189             (unsigned long) timeout.tv_usec);
 190   struct test_response response;
 191   TEST_VERIFY_EXIT (clnt_call (clnt, proc,
 192                                xdr_test_query, (void *) &query,
 193                                xdr_test_response, (void *) &response,
 194                                timeout)
 195                     == RPC_SUCCESS);
 196   return response;
 197 }
 198
 199 static void
 200 test_call_timeout (CLIENT *clnt, int proc, struct test_query query,
 201                    struct timeval timeout)
 202 {
 203   struct test_response response;
 204   TEST_VERIFY (clnt_call (clnt, proc,
 205                           xdr_test_query, (void *) &query,
 206                           xdr_test_response, (void *) &response,
 207                           timeout)
 208                == RPC_TIMEDOUT);
 209 }
 210
 211 /* Complete one regular RPC call to drain the server socket
 212    buffer.  Resets the sequence number.  */
 213 static void
 214 test_call_flush (CLIENT *clnt)
 215 {
 216   /* This needs a longer timeout to flush out all pending requests.
 217      The choice of 5 seconds is larger than the per-response timeouts
 218      requested via the timeout_ms field.  */
 219   if (test_verbose)
 220     printf ("info: flushing pending queries\n");
 221   TEST_VERIFY_EXIT (clnt_call (clnt, PROC_RESET_SEQ,
 222                                (xdrproc_t) xdr_void, NULL,
 223                                (xdrproc_t) xdr_void, NULL,
 224                                ((struct timeval) { 5, 0 }))
 225                     == RPC_SUCCESS);
 226 }
 227
 228 /* Return the number seconds since an arbitrary point in time.  */
 229 static double
 230 get_ticks (void)
 231 {
 232   {
 233     struct timespec ts;
 234     if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
 235       return ts.tv_sec + ts.tv_nsec * 1e-9;
 236   }
 237   {
 238     struct timeval tv;
 239     TEST_VERIFY_EXIT (gettimeofday (&tv, NULL) == 0);
 240     return tv.tv_sec + tv.tv_usec * 1e-6;
 241   }
 242 }
 243
 244 static void
 245 test_udp_server (int port)
 246 {
 247   struct sockaddr_in sin =
 248     {
 249       .sin_family = AF_INET,
 250       .sin_addr.s_addr = htonl (INADDR_LOOPBACK),
 251       .sin_port = htons (port)
 252     };
 253   int sock = RPC_ANYSOCK;
 254
 255   /* The client uses a 1.5 second timeout for retries.  The timeouts
 256      are arbitrary, but chosen so that there is a substantial gap
 257      between them, but the total time spent waiting is not too
 258      large.  */
 259   CLIENT *clnt = clntudp_create (&sin, PROGNUM, VERSNUM,
 260                                  (struct timeval) { 1, 500 * 1000 },
 261                                  &sock);
 262   TEST_VERIFY_EXIT (clnt != NULL);
 263
 264   /* Basic call/response test.  */
 265   struct test_response response = test_call
 266     (clnt, PROC_ADD,
 267      (struct test_query) { .a = 17, .b = 4 },
 268      (struct timeval) { 3, 0 });
 269   TEST_VERIFY (response.sum == 21);
 270   TEST_VERIFY (response.seq == 1);
 271
 272   /* Check that garbage packets do not interfere with timeout
 273      processing.  */
 274   double before = get_ticks ();
 275   response = test_call
 276     (clnt, PROC_ADD,
 277      (struct test_query) {
 278        .a = 19, .b = 4, .timeout_ms = 500, .garbage_packets = 21,
 279      },
 280      (struct timeval) { 3, 0 });
 281   TEST_VERIFY (response.sum == 23);
 282   TEST_VERIFY (response.seq == 2);
 283   double after = get_ticks ();
 284   if (test_verbose)
 285     printf ("info: 21 garbage packets took %f seconds\n", after - before);
 286   /* Expected timeout is 0.5 seconds.  Add some slack in case process
 287      scheduling delays processing the query or response, but do not
 288      accept a retry (which would happen at 1.5 seconds).  */
 289   TEST_VERIFY (0.5 <= after - before);
 290   TEST_VERIFY (after - before < 1.2);
 291   test_call_flush (clnt);
 292
 293   /* Check that missing a response introduces a 1.5 second timeout, as
 294      requested when calling clntudp_create.  */
 295   before = get_ticks ();
 296   response = test_call
 297     (clnt, PROC_ADD,
 298      (struct test_query) { .a = 170, .b = 40, .wait_for_seq = 2 },
 299      (struct timeval) { 3, 0 });
 300   TEST_VERIFY (response.sum == 210);
 301   TEST_VERIFY (response.seq == 2);
 302   after = get_ticks ();
 303   if (test_verbose)
 304     printf ("info: skipping one response took %f seconds\n",
 305             after - before);
 306   /* Expected timeout is 1.5 seconds.  Do not accept a second retry
 307      (which would happen at 3 seconds).  */
 308   TEST_VERIFY (1.5 <= after - before);
 309   TEST_VERIFY (after - before < 2.9);
 310   test_call_flush (clnt);
 311
 312   /* Check that the overall timeout wins against the per-query
 313      timeout.  */
 314   before = get_ticks ();
 315   test_call_timeout
 316     (clnt, PROC_ADD,
 317      (struct test_query) { .a = 170, .b = 41, .wait_for_seq = 2 },
 318      (struct timeval) { 0, 750 * 1000 });
 319   after = get_ticks ();
 320   if (test_verbose)
 321     printf ("info: 0.75 second timeout took %f seconds\n",
 322             after - before);
 323   TEST_VERIFY (0.75 <= after - before);
 324   TEST_VERIFY (after - before < 1.4);
 325   test_call_flush (clnt);
 326
 327   for (int with_garbage = 0; with_garbage < 2; ++with_garbage)
 328     {
 329       /* Check that no response at all causes the client to bail out.  */
 330       before = get_ticks ();
 331       test_call_timeout
 332         (clnt, PROC_ADD,
 333          (struct test_query) {
 334            .a = 170, .b = 40, .timeout_ms = 1200,
 335            .garbage_packets = with_garbage * 21
 336          },
 337          (struct timeval) { 0, 750 * 1000 });
 338       after = get_ticks ();
 339       if (test_verbose)
 340         printf ("info: test_udp_server: 0.75 second timeout took %f seconds"
 341                 " (garbage %d)\n",
 342                 after - before, with_garbage);
 343       TEST_VERIFY (0.75 <= after - before);
 344       TEST_VERIFY (after - before < 1.4);
 345       test_call_flush (clnt);
 346
 347       /* As above, but check the total timeout.  */
 348       before = get_ticks ();
 349       test_call_timeout
 350         (clnt, PROC_ADD,
 351          (struct test_query) {
 352            .a = 170, .b = 40, .timeout_ms = 3000,
 353            .garbage_packets = with_garbage * 30
 354          },
 355          (struct timeval) { 2, 500 * 1000 });
 356       after = get_ticks ();
 357       if (test_verbose)
 358         printf ("info: test_udp_server: 2.5 second timeout took %f seconds"
 359                 " (garbage %d)\n",
 360                 after - before, with_garbage);
 361       TEST_VERIFY (2.5 <= after - before);
 362       TEST_VERIFY (after - before < 3.0);
 363       test_call_flush (clnt);
 364     }
 365
 366   TEST_VERIFY_EXIT (clnt_call (clnt, PROC_EXIT,
 367                                (xdrproc_t) xdr_void, NULL,
 368                                (xdrproc_t) xdr_void, NULL,
 369                                ((struct timeval) { 5, 0 }))
 370                     == RPC_SUCCESS);
 371   clnt_destroy (clnt);
 372 }
 373
 374 static int
 375 do_test (void)
 376 {
 377   support_become_root ();
 378   support_enter_network_namespace ();
 379
 380   SVCXPRT *transport = svcudp_create (RPC_ANYSOCK);
 381   TEST_VERIFY_EXIT (transport != NULL);
 382   TEST_VERIFY (svc_register (transport, PROGNUM, VERSNUM, server_dispatch, 0));
 383
 384   pid_t pid = xfork ();
 385   if (pid == 0)
 386     {
 387       svc_run ();
 388       FAIL_EXIT1 ("supposed to be unreachable");
 389     }
 390   test_udp_server (transport->xp_port);
 391
 392   int status;
 393   xwaitpid (pid, &status, 0);
 394   TEST_VERIFY (WIFEXITED (status) && WEXITSTATUS (status) == EXIT_MARKER);
 395
 396   SVC_DESTROY (transport);
 397   return 0;
 398 }
 399
 400 /* The minimum run time is around 17 seconds.  */
 401 #define TIMEOUT 25
 402 #include <support/test-driver.c>