sunrpc/tst-udp-timeout.c

   1 /* Test timeout handling in the UDP client.
   2    Copyright (C) 2017-2023 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    <https://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 #include <stdlib.h>
  33
  34 static pid_t server_pid;
  35
  36 /* Test data serialization and deserialization.   */
  37
  38 struct test_query
  39 {
  40   uint32_t a;
  41   uint32_t b;
  42   uint32_t timeout_ms;
  43   uint32_t wait_for_seq;
  44   uint32_t garbage_packets;
  45 };
  46
  47 static bool_t
  48 xdr_test_query (XDR *xdrs, void *data, ...)
  49 {
  50   struct test_query *p = data;
  51   return xdr_uint32_t (xdrs, &p->a)
  52     && xdr_uint32_t (xdrs, &p->b)
  53     && xdr_uint32_t (xdrs, &p->timeout_ms)
  54     && xdr_uint32_t (xdrs, &p->wait_for_seq)
  55     && xdr_uint32_t (xdrs, &p->garbage_packets);
  56 }
  57
  58 struct test_response
  59 {
  60   uint32_t seq;
  61   uint32_t sum;
  62 };
  63
  64 static bool_t
  65 xdr_test_response (XDR *xdrs, void *data, ...)
  66 {
  67   struct test_response *p = data;
  68   return xdr_uint32_t (xdrs, &p->seq)
  69     && xdr_uint32_t (xdrs, &p->sum);
  70 }
  71
  72 /* Implementation of the test server.  */
  73
  74 enum
  75   {
  76     /* RPC parameters, chosen at random.  */
  77     PROGNUM = 15717,
  78     VERSNUM = 13689,
  79
  80     /* Main RPC operation.  */
  81     PROC_ADD = 1,
  82
  83     /* Reset the sequence number.  */
  84     PROC_RESET_SEQ,
  85
  86     /* Request process termination.  */
  87     PROC_EXIT,
  88
  89     /* Special exit status to mark successful processing.  */
  90     EXIT_MARKER = 55,
  91   };
  92
  93 static void
  94 server_dispatch (struct svc_req *request, SVCXPRT *transport)
  95 {
  96   /* Query sequence number.  */
  97   static uint32_t seq = 0;
  98   ++seq;
  99
 100   if (test_verbose)
 101     printf ("info: server_dispatch seq=%u rq_proc=%lu\n",
 102             seq, request->rq_proc);
 103
 104   switch (request->rq_proc)
 105     {
 106     case PROC_ADD:
 107       {
 108         struct test_query query;
 109         memset (&query, 0xc0, sizeof (query));
 110         TEST_VERIFY_EXIT
 111           (svc_getargs (transport, xdr_test_query,
 112                         (void *) &query));
 113
 114         if (test_verbose)
 115           printf ("  a=%u b=%u timeout_ms=%u wait_for_seq=%u"
 116                   " garbage_packets=%u\n",
 117                   query.a, query.b, query.timeout_ms, query.wait_for_seq,
 118                   query.garbage_packets);
 119
 120         if (seq < query.wait_for_seq)
 121           {
 122             /* No response at this point.  */
 123             if (test_verbose)
 124               printf ("  skipped response\n");
 125             break;
 126           }
 127
 128         if (query.garbage_packets > 0)
 129           {
 130             int per_packet_timeout;
 131             if (query.timeout_ms > 0)
 132               per_packet_timeout
 133                 = query.timeout_ms * 1000 / query.garbage_packets;
 134             else
 135               per_packet_timeout = 0;
 136
 137             char buf[20];
 138             memset (&buf, 0xc0, sizeof (buf));
 139             for (int i = 0; i < query.garbage_packets; ++i)
 140               {
 141                 /* 13 is relatively prime to 20 = sizeof (buf) + 1, so
 142                    the len variable will cover the entire interval
 143                    [0, 20] if query.garbage_packets is sufficiently
 144                    large.  */
 145                 size_t len = (i * 13 + 1) % (sizeof (buf) + 1);
 146                 TEST_VERIFY (sendto (transport->xp_sock,
 147                                      buf, len, MSG_NOSIGNAL,
 148                                      (struct sockaddr *) &transport->xp_raddr,
 149                                      transport->xp_addrlen) == len);
 150                 if (per_packet_timeout > 0)
 151                   usleep (per_packet_timeout);
 152               }
 153           }
 154         else if (query.timeout_ms > 0)
 155           usleep (query.timeout_ms * 1000);
 156
 157         struct test_response response =
 158           {
 159             .seq = seq,
 160             .sum = query.a + query.b,
 161           };
 162         TEST_VERIFY (svc_sendreply (transport, xdr_test_response,
 163                                     (void *) &response));
 164       }
 165       break;
 166
 167     case PROC_RESET_SEQ:
 168       seq = 0;
 169       TEST_VERIFY (svc_sendreply (transport, (xdrproc_t) xdr_void, NULL));
 170       break;
 171
 172     case PROC_EXIT:
 173       TEST_VERIFY (svc_sendreply (transport, (xdrproc_t) xdr_void, NULL));
 174       _exit (EXIT_MARKER);
 175       break;
 176
 177     default:
 178       FAIL_EXIT1 ("invalid rq_proc value: %lu", request->rq_proc);
 179       break;
 180     }
 181 }
 182
 183 /* Function to be called before exit to make sure the
 184    server process is properly killed.  */
 185 static void
 186 kill_server (void)
 187 {
 188   kill (server_pid, SIGTERM);
 189 }
 190
 191 /* Implementation of the test client.  */
 192
 193 static struct test_response
 194 test_call (CLIENT *clnt, int proc, struct test_query query,
 195            struct timeval timeout)
 196 {
 197   if (test_verbose)
 198     printf ("info: test_call proc=%d timeout=%lu.%06lu\n",
 199             proc, (unsigned long) timeout.tv_sec,
 200             (unsigned long) timeout.tv_usec);
 201   struct test_response response;
 202   TEST_VERIFY_EXIT (clnt_call (clnt, proc,
 203                                xdr_test_query, (void *) &query,
 204                                xdr_test_response, (void *) &response,
 205                                timeout)
 206                     == RPC_SUCCESS);
 207   return response;
 208 }
 209
 210 static void
 211 test_call_timeout (CLIENT *clnt, int proc, struct test_query query,
 212                    struct timeval timeout)
 213 {
 214   struct test_response response;
 215   TEST_VERIFY (clnt_call (clnt, proc,
 216                           xdr_test_query, (void *) &query,
 217                           xdr_test_response, (void *) &response,
 218                           timeout)
 219                == RPC_TIMEDOUT);
 220 }
 221
 222 /* Complete one regular RPC call to drain the server socket
 223    buffer.  Resets the sequence number.  */
 224 static void
 225 test_call_flush (CLIENT *clnt)
 226 {
 227   /* This needs a longer timeout to flush out all pending requests.
 228      The choice of 5 seconds is larger than the per-response timeouts
 229      requested via the timeout_ms field.  */
 230   if (test_verbose)
 231     printf ("info: flushing pending queries\n");
 232   TEST_VERIFY_EXIT (clnt_call (clnt, PROC_RESET_SEQ,
 233                                (xdrproc_t) xdr_void, NULL,
 234                                (xdrproc_t) xdr_void, NULL,
 235                                ((struct timeval) { 5, 0 }))
 236                     == RPC_SUCCESS);
 237 }
 238
 239 /* Return the number seconds since an arbitrary point in time.  */
 240 static double
 241 get_ticks (void)
 242 {
 243   {
 244     struct timespec ts;
 245     if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
 246       return ts.tv_sec + ts.tv_nsec * 1e-9;
 247   }
 248   {
 249     struct timeval tv;
 250     TEST_VERIFY_EXIT (gettimeofday (&tv, NULL) == 0);
 251     return tv.tv_sec + tv.tv_usec * 1e-6;
 252   }
 253 }
 254
 255 static void
 256 test_udp_server (int port)
 257 {
 258   struct sockaddr_in sin =
 259     {
 260       .sin_family = AF_INET,
 261       .sin_addr.s_addr = htonl (INADDR_LOOPBACK),
 262       .sin_port = htons (port)
 263     };
 264   int sock = RPC_ANYSOCK;
 265
 266   /* The client uses a 1.5 second timeout for retries.  The timeouts
 267      are arbitrary, but chosen so that there is a substantial gap
 268      between them, but the total time spent waiting is not too
 269      large.  */
 270   CLIENT *clnt = clntudp_create (&sin, PROGNUM, VERSNUM,
 271                                  (struct timeval) { 1, 500 * 1000 },
 272                                  &sock);
 273   TEST_VERIFY_EXIT (clnt != NULL);
 274
 275   /* Basic call/response test.  */
 276   struct test_response response = test_call
 277     (clnt, PROC_ADD,
 278      (struct test_query) { .a = 17, .b = 4 },
 279      (struct timeval) { 3, 0 });
 280   TEST_VERIFY (response.sum == 21);
 281   TEST_VERIFY (response.seq == 1);
 282
 283   /* Check that garbage packets do not interfere with timeout
 284      processing.  */
 285   double before = get_ticks ();
 286   response = test_call
 287     (clnt, PROC_ADD,
 288      (struct test_query) {
 289        .a = 19, .b = 4, .timeout_ms = 500, .garbage_packets = 21,
 290      },
 291      (struct timeval) { 3, 0 });
 292   TEST_VERIFY (response.sum == 23);
 293   TEST_VERIFY (response.seq == 2);
 294   double after = get_ticks ();
 295   if (test_verbose)
 296     printf ("info: 21 garbage packets took %f seconds\n", after - before);
 297   /* Expected timeout is 0.5 seconds.  Add some slack for rounding errors and
 298      in case process scheduling delays processing the query or response, but
 299      do not accept a retry (which would happen at 1.5 seconds).  */
 300   TEST_VERIFY (0.45 <= after - before);
 301   TEST_VERIFY (after - before < 1.2);
 302   test_call_flush (clnt);
 303
 304   /* Check that missing a response introduces a 1.5 second timeout, as
 305      requested when calling clntudp_create.  */
 306   before = get_ticks ();
 307   response = test_call
 308     (clnt, PROC_ADD,
 309      (struct test_query) { .a = 170, .b = 40, .wait_for_seq = 2 },
 310      (struct timeval) { 3, 0 });
 311   TEST_VERIFY (response.sum == 210);
 312   TEST_VERIFY (response.seq == 2);
 313   after = get_ticks ();
 314   if (test_verbose)
 315     printf ("info: skipping one response took %f seconds\n",
 316             after - before);
 317   /* Expected timeout is 1.5 seconds.  Do not accept a second retry
 318      (which would happen at 3 seconds).  */
 319   TEST_VERIFY (1.45 <= after - before);
 320   TEST_VERIFY (after - before < 2.9);
 321   test_call_flush (clnt);
 322
 323   /* Check that the overall timeout wins against the per-query
 324      timeout.  */
 325   before = get_ticks ();
 326   test_call_timeout
 327     (clnt, PROC_ADD,
 328      (struct test_query) { .a = 170, .b = 41, .wait_for_seq = 2 },
 329      (struct timeval) { 0, 750 * 1000 });
 330   after = get_ticks ();
 331   if (test_verbose)
 332     printf ("info: 0.75 second timeout took %f seconds\n",
 333             after - before);
 334   TEST_VERIFY (0.70 <= after - before);
 335   TEST_VERIFY (after - before < 1.4);
 336   test_call_flush (clnt);
 337
 338   for (int with_garbage = 0; with_garbage < 2; ++with_garbage)
 339     {
 340       /* Check that no response at all causes the client to bail out.  */
 341       before = get_ticks ();
 342       test_call_timeout
 343         (clnt, PROC_ADD,
 344          (struct test_query) {
 345            .a = 170, .b = 40, .timeout_ms = 1200,
 346            .garbage_packets = with_garbage * 21
 347          },
 348          (struct timeval) { 0, 750 * 1000 });
 349       after = get_ticks ();
 350       if (test_verbose)
 351         printf ("info: test_udp_server: 0.75 second timeout took %f seconds"
 352                 " (garbage %d)\n",
 353                 after - before, with_garbage);
 354       TEST_VERIFY (0.70 <= after - before);
 355       TEST_VERIFY (after - before < 1.4);
 356       test_call_flush (clnt);
 357
 358       /* As above, but check the total timeout.  */
 359       before = get_ticks ();
 360       test_call_timeout
 361         (clnt, PROC_ADD,
 362          (struct test_query) {
 363            .a = 170, .b = 40, .timeout_ms = 3000,
 364            .garbage_packets = with_garbage * 30
 365          },
 366          (struct timeval) { 2, 500 * 1000 });
 367       after = get_ticks ();
 368       if (test_verbose)
 369         printf ("info: test_udp_server: 2.5 second timeout took %f seconds"
 370                 " (garbage %d)\n",
 371                 after - before, with_garbage);
 372       TEST_VERIFY (2.45 <= after - before);
 373       TEST_VERIFY (after - before < 3.0);
 374       test_call_flush (clnt);
 375     }
 376
 377   TEST_VERIFY_EXIT (clnt_call (clnt, PROC_EXIT,
 378                                (xdrproc_t) xdr_void, NULL,
 379                                (xdrproc_t) xdr_void, NULL,
 380                                ((struct timeval) { 5, 0 }))
 381                     == RPC_SUCCESS);
 382   clnt_destroy (clnt);
 383 }
 384
 385 static int
 386 do_test (void)
 387 {
 388   support_become_root ();
 389   support_enter_network_namespace ();
 390
 391   SVCXPRT *transport = svcudp_create (RPC_ANYSOCK);
 392   TEST_VERIFY_EXIT (transport != NULL);
 393   TEST_VERIFY (svc_register (transport, PROGNUM, VERSNUM, server_dispatch, 0));
 394
 395   server_pid = xfork ();
 396   if (server_pid == 0)
 397     {
 398       svc_run ();
 399       FAIL_EXIT1 ("supposed to be unreachable");
 400     }
 401   atexit (kill_server);
 402   test_udp_server (transport->xp_port);
 403
 404   int status;
 405   xwaitpid (server_pid, &status, 0);
 406   TEST_VERIFY (WIFEXITED (status) && WEXITSTATUS (status) == EXIT_MARKER);
 407
 408   SVC_DESTROY (transport);
 409   return 0;
 410 }
 411
 412 /* The minimum run time is around 17 seconds.  */
 413 #define TIMEOUT 25
 414 #include <support/test-driver.c>