tests/test-fcntl.c

   1 /* Test of fcntl(2).
   2    Copyright (C) 2009-2017 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 <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include <fcntl.h>
  23
  24 #include "signature.h"
  25 SIGNATURE_CHECK (fcntl, int, (int, int, ...));
  26
  27 /* Helpers.  */
  28 #include <errno.h>
  29 #include <stdarg.h>
  30 #include <stdbool.h>
  31 #include <unistd.h>
  32
  33 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  34 /* Get declarations of the native Windows API functions.  */
  35 # define WIN32_LEAN_AND_MEAN
  36 # include <windows.h>
  37 /* Get _get_osfhandle.  */
  38 # include "msvc-nothrow.h"
  39 #endif
  40
  41 #include "binary-io.h"
  42 #include "macros.h"
  43
  44 #if !O_BINARY
  45 # define setmode(f,m) zero ()
  46 static int zero (void) { return 0; }
  47 #endif
  48
  49 /* Return true if FD is open.  */
  50 static bool
  51 is_open (int fd)
  52 {
  53 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  54   /* On native Windows, the initial state of unassigned standard file
  55      descriptors is that they are open but point to an
  56      INVALID_HANDLE_VALUE, and there is no fcntl.  */
  57   return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
  58 #else
  59 # ifndef F_GETFL
  60 #  error Please port fcntl to your platform
  61 # endif
  62   return 0 <= fcntl (fd, F_GETFL);
  63 #endif
  64 }
  65
  66 /* Return true if FD is open and inheritable across exec/spawn.  */
  67 static bool
  68 is_inheritable (int fd)
  69 {
  70 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  71   /* On native Windows, the initial state of unassigned standard file
  72      descriptors is that they are open but point to an
  73      INVALID_HANDLE_VALUE, and there is no fcntl.  */
  74   HANDLE h = (HANDLE) _get_osfhandle (fd);
  75   DWORD flags;
  76   if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
  77     return false;
  78   return (flags & HANDLE_FLAG_INHERIT) != 0;
  79 #else
  80 # ifndef F_GETFD
  81 #  error Please port fcntl to your platform
  82 # endif
  83   int i = fcntl (fd, F_GETFD);
  84   return 0 <= i && (i & FD_CLOEXEC) == 0;
  85 #endif
  86 }
  87
  88 /* Return non-zero if FD is open in the given MODE, which is either
  89    O_TEXT or O_BINARY.  */
  90 static bool
  91 is_mode (int fd, int mode)
  92 {
  93   int value = setmode (fd, O_BINARY);
  94   setmode (fd, value);
  95   return mode == value;
  96 }
  97
  98 /* Since native fcntl can have more supported operations than our
  99    replacement is aware of, and since various operations assign
 100    different types to the vararg argument, a wrapper around fcntl must
 101    be able to pass a vararg of unknown type on through to the original
 102    fcntl.  Make sure that this works properly: func1 behaves like the
 103    original fcntl interpreting the vararg as an int or a pointer to a
 104    struct, and func2 behaves like rpl_fcntl that doesn't know what
 105    type to forward.  */
 106 struct dummy_struct
 107 {
 108   long filler;
 109   int value;
 110 };
 111 static int
 112 func1 (int a, ...)
 113 {
 114   va_list arg;
 115   int i;
 116   va_start (arg, a);
 117   if (a < 4)
 118     i = va_arg (arg, int);
 119   else
 120     {
 121       struct dummy_struct *s = va_arg (arg, struct dummy_struct *);
 122       i = s->value;
 123     }
 124   va_end (arg);
 125   return i;
 126 }
 127 static int
 128 func2 (int a, ...)
 129 {
 130   va_list arg;
 131   void *p;
 132   va_start (arg, a);
 133   p = va_arg (arg, void *);
 134   va_end (arg);
 135   return func1 (a, p);
 136 }
 137
 138 /* Ensure that all supported fcntl actions are distinct, and
 139    usable in preprocessor expressions.  */
 140 static void
 141 check_flags (void)
 142 {
 143   switch (0)
 144     {
 145     case F_DUPFD:
 146 #if F_DUPFD
 147 #endif
 148
 149     case F_DUPFD_CLOEXEC:
 150 #if F_DUPFD_CLOEXEC
 151 #endif
 152
 153     case F_GETFD:
 154 #if F_GETFD
 155 #endif
 156
 157 #ifdef F_SETFD
 158     case F_SETFD:
 159 # if F_SETFD
 160 # endif
 161 #endif
 162
 163 #ifdef F_GETFL
 164     case F_GETFL:
 165 # if F_GETFL
 166 # endif
 167 #endif
 168
 169 #ifdef F_SETFL
 170     case F_SETFL:
 171 # if F_SETFL
 172 # endif
 173 #endif
 174
 175 #ifdef F_GETOWN
 176     case F_GETOWN:
 177 # if F_GETOWN
 178 # endif
 179 #endif
 180
 181 #ifdef F_SETOWN
 182     case F_SETOWN:
 183 # if F_SETOWN
 184 # endif
 185 #endif
 186
 187 #ifdef F_GETLK
 188     case F_GETLK:
 189 # if F_GETLK
 190 # endif
 191 #endif
 192
 193 #ifdef F_SETLK
 194     case F_SETLK:
 195 # if F_SETLK
 196 # endif
 197 #endif
 198
 199 #ifdef F_SETLKW
 200     case F_SETLKW:
 201 # if F_SETLKW
 202 # endif
 203 #endif
 204
 205       ;
 206     }
 207 }
 208
 209 int
 210 main (void)
 211 {
 212   const char *file = "test-fcntl.tmp";
 213   int fd;
 214   int bad_fd = getdtablesize ();
 215
 216   /* Sanity check that rpl_fcntl is likely to work.  */
 217   ASSERT (func2 (1, 2) == 2);
 218   ASSERT (func2 (2, -2) == -2);
 219   ASSERT (func2 (3, 0x80000000) == 0x80000000);
 220   {
 221     struct dummy_struct s = { 0L, 4 };
 222     ASSERT (func2 (4, &s) == 4);
 223   }
 224   check_flags ();
 225
 226   /* Assume std descriptors were provided by invoker, and ignore fds
 227      that might have been inherited.  */
 228   fd = creat (file, 0600);
 229   ASSERT (STDERR_FILENO < fd);
 230   close (fd + 1);
 231   close (fd + 2);
 232
 233   /* For F_DUPFD*, the source must be valid.  */
 234   errno = 0;
 235   ASSERT (fcntl (-1, F_DUPFD, 0) == -1);
 236   ASSERT (errno == EBADF);
 237   errno = 0;
 238   ASSERT (fcntl (fd + 1, F_DUPFD, 0) == -1);
 239   ASSERT (errno == EBADF);
 240   errno = 0;
 241   ASSERT (fcntl (bad_fd, F_DUPFD, 0) == -1);
 242   ASSERT (errno == EBADF);
 243   errno = 0;
 244   ASSERT (fcntl (-1, F_DUPFD_CLOEXEC, 0) == -1);
 245   ASSERT (errno == EBADF);
 246   errno = 0;
 247   ASSERT (fcntl (fd + 1, F_DUPFD_CLOEXEC, 0) == -1);
 248   ASSERT (errno == EBADF);
 249   errno = 0;
 250   ASSERT (fcntl (bad_fd, F_DUPFD_CLOEXEC, 0) == -1);
 251   ASSERT (errno == EBADF);
 252
 253   /* For F_DUPFD*, the destination must be valid.  */
 254   errno = 0;
 255   ASSERT (fcntl (fd, F_DUPFD, -1) == -1);
 256   ASSERT (errno == EINVAL);
 257   errno = 0;
 258   ASSERT (fcntl (fd, F_DUPFD, bad_fd) == -1);
 259   ASSERT (errno == EINVAL);
 260   errno = 0;
 261   ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, -1) == -1);
 262   ASSERT (errno == EINVAL);
 263   errno = 0;
 264   ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, bad_fd) == -1);
 265   ASSERT (errno == EINVAL);
 266
 267   /* For F_DUPFD*, check for correct inheritance, as well as
 268      preservation of text vs. binary.  */
 269   setmode (fd, O_BINARY);
 270   ASSERT (is_open (fd));
 271   ASSERT (!is_open (fd + 1));
 272   ASSERT (!is_open (fd + 2));
 273   ASSERT (is_inheritable (fd));
 274   ASSERT (is_mode (fd, O_BINARY));
 275
 276   ASSERT (fcntl (fd, F_DUPFD, fd) == fd + 1);
 277   ASSERT (is_open (fd));
 278   ASSERT (is_open (fd + 1));
 279   ASSERT (!is_open (fd + 2));
 280   ASSERT (is_inheritable (fd + 1));
 281   ASSERT (is_mode (fd, O_BINARY));
 282   ASSERT (is_mode (fd + 1, O_BINARY));
 283   ASSERT (close (fd + 1) == 0);
 284
 285   ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, fd + 2) == fd + 2);
 286   ASSERT (is_open (fd));
 287   ASSERT (!is_open (fd + 1));
 288   ASSERT (is_open (fd + 2));
 289   ASSERT (is_inheritable (fd));
 290   ASSERT (!is_inheritable (fd + 2));
 291   ASSERT (is_mode (fd, O_BINARY));
 292   ASSERT (is_mode (fd + 2, O_BINARY));
 293   ASSERT (close (fd) == 0);
 294
 295   setmode (fd + 2, O_TEXT);
 296   ASSERT (fcntl (fd + 2, F_DUPFD, fd + 1) == fd + 1);
 297   ASSERT (!is_open (fd));
 298   ASSERT (is_open (fd + 1));
 299   ASSERT (is_open (fd + 2));
 300   ASSERT (is_inheritable (fd + 1));
 301   ASSERT (!is_inheritable (fd + 2));
 302   ASSERT (is_mode (fd + 1, O_TEXT));
 303   ASSERT (is_mode (fd + 2, O_TEXT));
 304   ASSERT (close (fd + 1) == 0);
 305
 306   ASSERT (fcntl (fd + 2, F_DUPFD_CLOEXEC, 0) == fd);
 307   ASSERT (is_open (fd));
 308   ASSERT (!is_open (fd + 1));
 309   ASSERT (is_open (fd + 2));
 310   ASSERT (!is_inheritable (fd));
 311   ASSERT (!is_inheritable (fd + 2));
 312   ASSERT (is_mode (fd, O_TEXT));
 313   ASSERT (is_mode (fd + 2, O_TEXT));
 314   ASSERT (close (fd + 2) == 0);
 315
 316   /* Test F_GETFD on invalid file descriptors.  */
 317   errno = 0;
 318   ASSERT (fcntl (-1, F_GETFD) == -1);
 319   ASSERT (errno == EBADF);
 320   errno = 0;
 321   ASSERT (fcntl (fd + 1, F_GETFD) == -1);
 322   ASSERT (errno == EBADF);
 323   errno = 0;
 324   ASSERT (fcntl (bad_fd, F_GETFD) == -1);
 325   ASSERT (errno == EBADF);
 326
 327   /* Test F_GETFD, the FD_CLOEXEC bit.  */
 328   {
 329     int result = fcntl (fd, F_GETFD);
 330     ASSERT (0 <= result);
 331     ASSERT ((result & FD_CLOEXEC) == FD_CLOEXEC);
 332     ASSERT (dup (fd) == fd + 1);
 333     result = fcntl (fd + 1, F_GETFD);
 334     ASSERT (0 <= result);
 335     ASSERT ((result & FD_CLOEXEC) == 0);
 336     ASSERT (close (fd + 1) == 0);
 337   }
 338
 339 #ifdef F_SETFD
 340   /* Test F_SETFD on invalid file descriptors.  */
 341   errno = 0;
 342   ASSERT (fcntl (-1, F_SETFD, 0) == -1);
 343   ASSERT (errno == EBADF);
 344   errno = 0;
 345   ASSERT (fcntl (fd + 1, F_SETFD, 0) == -1);
 346   ASSERT (errno == EBADF);
 347   errno = 0;
 348   ASSERT (fcntl (bad_fd, F_SETFD, 0) == -1);
 349   ASSERT (errno == EBADF);
 350 #endif
 351
 352 #ifdef F_GETFL
 353   /* Test F_GETFL on invalid file descriptors.  */
 354   errno = 0;
 355   ASSERT (fcntl (-1, F_GETFL) == -1);
 356   ASSERT (errno == EBADF);
 357   errno = 0;
 358   ASSERT (fcntl (fd + 1, F_GETFL) == -1);
 359   ASSERT (errno == EBADF);
 360   errno = 0;
 361   ASSERT (fcntl (bad_fd, F_GETFL) == -1);
 362   ASSERT (errno == EBADF);
 363 #endif
 364
 365 #ifdef F_SETFL
 366   /* Test F_SETFL on invalid file descriptors.  */
 367   errno = 0;
 368   ASSERT (fcntl (-1, F_SETFL, 0) == -1);
 369   ASSERT (errno == EBADF);
 370   errno = 0;
 371   ASSERT (fcntl (fd + 1, F_SETFL, 0) == -1);
 372   ASSERT (errno == EBADF);
 373   errno = 0;
 374   ASSERT (fcntl (bad_fd, F_SETFL, 0) == -1);
 375   ASSERT (errno == EBADF);
 376 #endif
 377
 378 #ifdef F_GETOWN
 379   /* Test F_GETOWN on invalid file descriptors.  */
 380   errno = 0;
 381   ASSERT (fcntl (-1, F_GETOWN) == -1);
 382   ASSERT (errno == EBADF);
 383   errno = 0;
 384   ASSERT (fcntl (fd + 1, F_GETOWN) == -1);
 385   ASSERT (errno == EBADF);
 386   errno = 0;
 387   ASSERT (fcntl (bad_fd, F_GETOWN) == -1);
 388   ASSERT (errno == EBADF);
 389 #endif
 390
 391 #ifdef F_SETOWN
 392   /* Test F_SETFL on invalid file descriptors.  */
 393   errno = 0;
 394   ASSERT (fcntl (-1, F_SETOWN, 0) == -1);
 395   ASSERT (errno == EBADF);
 396   errno = 0;
 397   ASSERT (fcntl (fd + 1, F_SETOWN, 0) == -1);
 398   ASSERT (errno == EBADF);
 399   errno = 0;
 400   ASSERT (fcntl (bad_fd, F_SETOWN, 0) == -1);
 401   ASSERT (errno == EBADF);
 402 #endif
 403
 404   /* Cleanup.  */
 405   ASSERT (close (fd) == 0);
 406   ASSERT (unlink (file) == 0);
 407
 408   return 0;
 409 }