tests/test-select.h

   1 /* Test of select() substitute.
   2    Copyright (C) 2008-2018 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Paolo Bonzini, 2008.  */
  18
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <sys/socket.h>
  22 #include <netinet/in.h>
  23 #include <arpa/inet.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <stdlib.h>
  27 #include <stdbool.h>
  28 #include <sys/ioctl.h>
  29 #include <errno.h>
  30
  31 #include "macros.h"
  32
  33 #if defined _WIN32 && ! defined __CYGWIN__
  34 # define WINDOWS_NATIVE
  35 #endif
  36
  37 #ifdef HAVE_SYS_WAIT_H
  38 # include <sys/wait.h>
  39 #endif
  40
  41 #define TEST_PORT       12345
  42
  43
  44 typedef int (*select_fn) (int, fd_set *, fd_set *, fd_set *, struct timeval *);
  45
  46
  47 /* Minimal testing infrastructure.  */
  48
  49 static int failures;
  50
  51 static void
  52 failed (const char *reason)
  53 {
  54   if (++failures > 1)
  55     printf ("  ");
  56   printf ("failed (%s)\n", reason);
  57 }
  58
  59 static int
  60 test (void (*fn) (select_fn), select_fn my_select, const char *msg)
  61 {
  62   failures = 0;
  63   printf ("%s... ", msg);
  64   fflush (stdout);
  65   fn (my_select);
  66
  67   if (!failures)
  68     printf ("passed\n");
  69
  70   return failures;
  71 }
  72
  73
  74 /* Funny socket code.  */
  75
  76 static int
  77 open_server_socket (void)
  78 {
  79   int s, x;
  80   struct sockaddr_in ia;
  81
  82   s = socket (AF_INET, SOCK_STREAM, 0);
  83
  84   x = 1;
  85   setsockopt (s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof (x));
  86
  87   memset (&ia, 0, sizeof (ia));
  88   ia.sin_family = AF_INET;
  89   inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr);
  90   ia.sin_port = htons (TEST_PORT);
  91   if (bind (s, (struct sockaddr *) &ia, sizeof (ia)) < 0)
  92     {
  93       perror ("bind");
  94       exit (77);
  95     }
  96
  97   if (listen (s, 1) < 0)
  98     {
  99       perror ("listen");
 100       exit (77);
 101     }
 102
 103   return s;
 104 }
 105
 106 static int
 107 connect_to_socket (bool blocking)
 108 {
 109   int s;
 110   struct sockaddr_in ia;
 111
 112   s = socket (AF_INET, SOCK_STREAM, 0);
 113
 114   memset (&ia, 0, sizeof (ia));
 115   ia.sin_family = AF_INET;
 116   inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr);
 117   ia.sin_port = htons (TEST_PORT);
 118
 119   if (!blocking)
 120     {
 121 #ifdef WINDOWS_NATIVE
 122       unsigned long iMode = 1;
 123       ioctl (s, FIONBIO, (char *) &iMode);
 124
 125 #elif defined F_GETFL
 126       int oldflags = fcntl (s, F_GETFL, NULL);
 127
 128       if (!(oldflags & O_NONBLOCK))
 129         fcntl (s, F_SETFL, oldflags | O_NONBLOCK);
 130 #endif
 131     }
 132
 133   if (connect (s, (struct sockaddr *) &ia, sizeof (ia)) < 0
 134       && (blocking || errno != EINPROGRESS))
 135     {
 136       perror ("connect");
 137       exit (77);
 138     }
 139
 140   return s;
 141 }
 142
 143
 144 /* A slightly more convenient interface to select(2).
 145    Waits until a specific event occurs on a file descriptor FD.
 146    EV is a bit mask of events to look for:
 147      SEL_IN - input can be polled without blocking,
 148      SEL_OUT - output can be provided without blocking,
 149      SEL_EXC - an exception occurred,
 150    A maximum wait time is specified by TIMEOUT.
 151    *TIMEOUT = { 0, 0 } means to return immediately,
 152    TIMEOUT = NULL means to wait indefinitely.  */
 153
 154 enum { SEL_IN = 1, SEL_OUT = 2, SEL_EXC = 4 };
 155
 156 static int
 157 do_select (int fd, int ev, struct timeval *timeout, select_fn my_select)
 158 {
 159   fd_set rfds, wfds, xfds;
 160   int r, rev;
 161
 162   FD_ZERO (&rfds);
 163   FD_ZERO (&wfds);
 164   FD_ZERO (&xfds);
 165   if (ev & SEL_IN)
 166     FD_SET (fd, &rfds);
 167   if (ev & SEL_OUT)
 168     FD_SET (fd, &wfds);
 169   if (ev & SEL_EXC)
 170     FD_SET (fd, &xfds);
 171   r = my_select (fd + 1, &rfds, &wfds, &xfds, timeout);
 172   if (r < 0)
 173     return r;
 174
 175   rev = 0;
 176   if (FD_ISSET (fd, &rfds))
 177     rev |= SEL_IN;
 178   if (FD_ISSET (fd, &wfds))
 179     rev |= SEL_OUT;
 180   if (FD_ISSET (fd, &xfds))
 181     rev |= SEL_EXC;
 182   if (rev && r == 0)
 183     failed ("select returned 0");
 184   if (rev & ~ev)
 185     failed ("select returned unrequested events");
 186
 187   return rev;
 188 }
 189
 190 static int
 191 do_select_nowait (int fd, int ev, select_fn my_select)
 192 {
 193   struct timeval tv0;
 194   tv0.tv_sec = 0;
 195   tv0.tv_usec = 0;
 196   return do_select (fd, ev, &tv0, my_select);
 197 }
 198
 199 static int
 200 do_select_wait (int fd, int ev, select_fn my_select)
 201 {
 202   return do_select (fd, ev, NULL, my_select);
 203 }
 204
 205
 206 /* Test select(2) for TTYs.  */
 207
 208 #ifdef INTERACTIVE
 209 static void
 210 test_tty (select_fn my_select)
 211 {
 212   if (do_select_nowait (0, SEL_IN, my_select) != 0)
 213     failed ("can read");
 214   if (do_select_nowait (0, SEL_OUT, my_select) == 0)
 215     failed ("cannot write");
 216
 217   if (do_select_wait (0, SEL_IN, my_select) == 0)
 218     failed ("return with infinite timeout");
 219
 220   getchar ();
 221   if (do_select_nowait (0, SEL_IN, my_select) != 0)
 222     failed ("can read after getc");
 223 }
 224 #endif
 225
 226
 227 static int
 228 do_select_bad_nfd_nowait (int nfd, select_fn my_select)
 229 {
 230   struct timeval tv0;
 231   tv0.tv_sec = 0;
 232   tv0.tv_usec = 0;
 233   errno = 0;
 234   return my_select (nfd, NULL, NULL, NULL, &tv0);
 235 }
 236
 237 static void
 238 test_bad_nfd (select_fn my_select)
 239 {
 240   if (do_select_bad_nfd_nowait (-1, my_select) != -1 || errno != EINVAL)
 241     failed ("invalid errno after negative nfds");
 242   /* Can't test FD_SETSIZE + 1 for EINVAL, since some systems allow
 243      dynamically larger set size by redefining FD_SETSIZE anywhere up
 244      to the actual maximum fd.  */
 245   /* if (do_select_bad_nfd_nowait (FD_SETSIZE + 1, my_select) != -1 */
 246   /*     || errno != EINVAL) */
 247   /*   failed ("invalid errno after bogus nfds"); */
 248 }
 249
 250 /* Test select(2) on invalid file descriptors.  */
 251
 252 static int
 253 do_select_bad_fd (int fd, int ev, struct timeval *timeout, select_fn my_select)
 254 {
 255   fd_set rfds, wfds, xfds;
 256
 257   FD_ZERO (&rfds);
 258   FD_ZERO (&wfds);
 259   FD_ZERO (&xfds);
 260   if (ev & SEL_IN)
 261     FD_SET (fd, &rfds);
 262   if (ev & SEL_OUT)
 263     FD_SET (fd, &wfds);
 264   if (ev & SEL_EXC)
 265     FD_SET (fd, &xfds);
 266   errno = 0;
 267   return my_select (fd + 1, &rfds, &wfds, &xfds, timeout);
 268   /* In this case, when fd is invalid, on some platforms, the bit for fd
 269      is left alone in the fd_set, whereas on other platforms it is cleared.
 270      So, don't check the bit for fd here.  */
 271 }
 272
 273 static int
 274 do_select_bad_fd_nowait (int fd, int ev, select_fn my_select)
 275 {
 276   struct timeval tv0;
 277   tv0.tv_sec = 0;
 278   tv0.tv_usec = 0;
 279   return do_select_bad_fd (fd, ev, &tv0, my_select);
 280 }
 281
 282 static void
 283 test_bad_fd (select_fn my_select)
 284 {
 285   /* This tests fails on OSF/1 and native Windows, even with fd = 16.  */
 286 #if !(defined __osf__ || defined WINDOWS_NATIVE)
 287   int fd;
 288
 289   /* On Linux, Mac OS X, *BSD, values of fd like 99 or 399 are discarded
 290      by the kernel early and therefore do *not* lead to EBADF, as required
 291      by POSIX.  */
 292 # if defined __linux__ || (defined __APPLE__ && defined __MACH__) || (defined __FreeBSD__ || defined __DragonFly__) || defined __OpenBSD__ || defined __NetBSD__
 293   fd = 14;
 294 # else
 295   fd = 99;
 296 # endif
 297   close (fd);
 298
 299   if (do_select_bad_fd_nowait (fd, SEL_IN, my_select) == 0 || errno != EBADF)
 300     failed ("invalid fd among rfds");
 301   if (do_select_bad_fd_nowait (fd, SEL_OUT, my_select) == 0 || errno != EBADF)
 302     failed ("invalid fd among wfds");
 303   if (do_select_bad_fd_nowait (fd, SEL_EXC, my_select) == 0 || errno != EBADF)
 304     failed ("invalid fd among xfds");
 305 #endif
 306 }
 307
 308
 309 /* Test select(2) for unconnected nonblocking sockets.  */
 310
 311 static void
 312 test_connect_first (select_fn my_select)
 313 {
 314   int s = open_server_socket ();
 315   struct sockaddr_in ia;
 316   socklen_t addrlen;
 317
 318   int c1, c2;
 319
 320   if (do_select_nowait (s, SEL_IN | SEL_EXC, my_select) != 0)
 321     failed ("can read, socket not connected");
 322
 323   c1 = connect_to_socket (false);
 324
 325   if (do_select_wait (s, SEL_IN | SEL_EXC, my_select) != SEL_IN)
 326     failed ("expecting readability on passive socket");
 327   if (do_select_nowait (s, SEL_IN | SEL_EXC, my_select) != SEL_IN)
 328     failed ("expecting readability on passive socket");
 329
 330   addrlen = sizeof (ia);
 331   c2 = accept (s, (struct sockaddr *) &ia, &addrlen);
 332   ASSERT (close (s) == 0);
 333   ASSERT (close (c1) == 0);
 334   ASSERT (close (c2) == 0);
 335 }
 336
 337
 338 /* Test select(2) for unconnected blocking sockets.  */
 339
 340 static void
 341 test_accept_first (select_fn my_select)
 342 {
 343 #ifndef WINDOWS_NATIVE
 344   int s = open_server_socket ();
 345   struct sockaddr_in ia;
 346   socklen_t addrlen;
 347   char buf[3];
 348   int c, pid;
 349
 350   pid = fork ();
 351   if (pid < 0)
 352     return;
 353
 354   if (pid == 0)
 355     {
 356       addrlen = sizeof (ia);
 357       c = accept (s, (struct sockaddr *) &ia, &addrlen);
 358       ASSERT (close (s) == 0);
 359       ASSERT (write (c, "foo", 3) == 3);
 360       ASSERT (read (c, buf, 3) == 3);
 361       shutdown (c, SHUT_RD);
 362       ASSERT (close (c) == 0);
 363       exit (0);
 364     }
 365   else
 366     {
 367       ASSERT (close (s) == 0);
 368       c = connect_to_socket (true);
 369       if (do_select_nowait (c, SEL_OUT, my_select) != SEL_OUT)
 370         failed ("cannot write after blocking connect");
 371       ASSERT (write (c, "foo", 3) == 3);
 372       wait (&pid);
 373       if (do_select_wait (c, SEL_IN, my_select) != SEL_IN)
 374         failed ("cannot read data left in the socket by closed process");
 375       ASSERT (read (c, buf, 3) == 3);
 376       ASSERT (write (c, "foo", 3) == 3);
 377       (void) close (c); /* may fail with errno = ECONNRESET */
 378     }
 379 #endif
 380 }
 381
 382
 383 /* Common code for pipes and connected sockets.  */
 384
 385 static void
 386 test_pair (int rd, int wd, select_fn my_select)
 387 {
 388   char buf[3];
 389   if (do_select_wait (wd, SEL_IN | SEL_OUT | SEL_EXC, my_select) != SEL_OUT)
 390     failed ("expecting writability before writing");
 391   if (do_select_nowait (wd, SEL_IN | SEL_OUT | SEL_EXC, my_select) != SEL_OUT)
 392     failed ("expecting writability before writing");
 393
 394   ASSERT (write (wd, "foo", 3) == 3);
 395   if (do_select_wait (rd, SEL_IN, my_select) != SEL_IN)
 396     failed ("expecting readability after writing");
 397   if (do_select_nowait (rd, SEL_IN, my_select) != SEL_IN)
 398     failed ("expecting readability after writing");
 399
 400   ASSERT (read (rd, buf, 3) == 3);
 401 }
 402
 403
 404 /* Test select(2) on connected sockets.  */
 405
 406 static void
 407 test_socket_pair (select_fn my_select)
 408 {
 409   struct sockaddr_in ia;
 410
 411   socklen_t addrlen = sizeof (ia);
 412   int s = open_server_socket ();
 413   int c1 = connect_to_socket (false);
 414   int c2 = accept (s, (struct sockaddr *) &ia, &addrlen);
 415
 416   ASSERT (close (s) == 0);
 417
 418   test_pair (c1, c2, my_select);
 419   ASSERT (close (c1) == 0);
 420   ASSERT (write (c2, "foo", 3) == 3);
 421   (void) close (c2); /* may fail with errno = ECONNRESET */
 422 }
 423
 424
 425 /* Test select(2) on pipes.  */
 426
 427 static void
 428 test_pipe (select_fn my_select)
 429 {
 430   int fd[2];
 431
 432   ASSERT (pipe (fd) == 0);
 433   test_pair (fd[0], fd[1], my_select);
 434   ASSERT (close (fd[0]) == 0);
 435   ASSERT (close (fd[1]) == 0);
 436 }
 437
 438
 439 /* Do them all.  */
 440
 441 static int
 442 test_function (select_fn my_select)
 443 {
 444   int result = 0;
 445
 446 #ifdef INTERACTIVE
 447   printf ("Please press Enter\n");
 448   test (test_tty, "TTY", my_select);
 449 #endif
 450
 451   result += test (test_bad_nfd, my_select, "Invalid nfd test");
 452   result += test (test_bad_fd, my_select, "Invalid fd test");
 453   result += test (test_connect_first, my_select, "Unconnected socket test");
 454   result += test (test_socket_pair, my_select, "Connected sockets test");
 455   result += test (test_accept_first, my_select, "General socket test with fork");
 456   result += test (test_pipe, my_select, "Pipe test");
 457
 458   return result;
 459 }