2 Copyright (C) 2009-2021 Free Software Foundation, Inc.
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.
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.
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/>. */
17 /* Written by Eric Blake <ebb9@byu.net>, 2009. */
24 #include "signature.h"
25 SIGNATURE_CHECK (fcntl, int, (int, int, ...));
33 #if defined _WIN32 && ! defined __CYGWIN__
34 /* Get declarations of the native Windows API functions. */
35 # define WIN32_LEAN_AND_MEAN
37 /* Get _get_osfhandle. */
38 # if GNULIB_MSVC_NOTHROW
39 # include "msvc-nothrow.h"
45 #include "binary-io.h"
49 # define set_binary_mode(f,m) zero ()
50 static int zero (void) { return 0; }
53 /* Return true if FD is open. */
57 #if defined _WIN32 && ! defined __CYGWIN__
58 /* On native Windows, the initial state of unassigned standard file
59 descriptors is that they are open but point to an
60 INVALID_HANDLE_VALUE, and there is no fcntl. */
61 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
64 # error Please port fcntl to your platform
66 return 0 <= fcntl (fd, F_GETFL);
70 /* Return true if FD is open and inheritable across exec/spawn. */
72 is_inheritable (int fd)
74 #if defined _WIN32 && ! defined __CYGWIN__
75 /* On native Windows, the initial state of unassigned standard file
76 descriptors is that they are open but point to an
77 INVALID_HANDLE_VALUE, and there is no fcntl. */
78 HANDLE h = (HANDLE) _get_osfhandle (fd);
80 if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
82 return (flags & HANDLE_FLAG_INHERIT) != 0;
85 # error Please port fcntl to your platform
87 int i = fcntl (fd, F_GETFD);
88 return 0 <= i && (i & FD_CLOEXEC) == 0;
92 /* Return non-zero if FD is open in the given MODE, which is either
93 O_TEXT or O_BINARY. */
95 is_mode (int fd, int mode)
97 int value = set_binary_mode (fd, O_BINARY);
98 set_binary_mode (fd, value);
102 /* Since native fcntl can have more supported operations than our
103 replacement is aware of, and since various operations assign
104 different types to the vararg argument, a wrapper around fcntl must
105 be able to pass a vararg of unknown type on through to the original
106 fcntl. Make sure that this works properly: func1 behaves like the
107 original fcntl interpreting the vararg as an int or a pointer to a
108 struct, and func2 behaves like rpl_fcntl that doesn't know what
122 i = va_arg (arg, int);
125 struct dummy_struct *s = va_arg (arg, struct dummy_struct *);
137 p = va_arg (arg, void *);
142 /* Ensure that all supported fcntl actions are distinct, and
143 usable in preprocessor expressions. */
153 case F_DUPFD_CLOEXEC:
215 main (int argc, char *argv[])
219 return (is_open (10) ? 42 : 0);
221 const char *file = "test-fcntl.tmp";
223 int bad_fd = getdtablesize ();
225 /* Sanity check that rpl_fcntl is likely to work. */
226 ASSERT (func2 (1, 2) == 2);
227 ASSERT (func2 (2, -2) == -2);
228 ASSERT (func2 (3, 0x80000000) == 0x80000000);
230 struct dummy_struct s = { 0L, 4 };
231 ASSERT (func2 (4, &s) == 4);
235 /* Assume std descriptors were provided by invoker, and ignore fds
236 that might have been inherited. */
237 fd = creat (file, 0600);
238 ASSERT (STDERR_FILENO < fd);
242 /* For F_DUPFD*, the source must be valid. */
244 ASSERT (fcntl (-1, F_DUPFD, 0) == -1);
245 ASSERT (errno == EBADF);
247 ASSERT (fcntl (fd + 1, F_DUPFD, 0) == -1);
248 ASSERT (errno == EBADF);
250 ASSERT (fcntl (bad_fd, F_DUPFD, 0) == -1);
251 ASSERT (errno == EBADF);
253 ASSERT (fcntl (-1, F_DUPFD_CLOEXEC, 0) == -1);
254 ASSERT (errno == EBADF);
256 ASSERT (fcntl (fd + 1, F_DUPFD_CLOEXEC, 0) == -1);
257 ASSERT (errno == EBADF);
259 ASSERT (fcntl (bad_fd, F_DUPFD_CLOEXEC, 0) == -1);
260 ASSERT (errno == EBADF);
262 /* For F_DUPFD*, the destination must be valid. */
264 ASSERT (fcntl (fd, F_DUPFD, -1) == -1);
265 ASSERT (errno == EINVAL);
267 ASSERT (fcntl (fd, F_DUPFD, bad_fd) == -1);
268 ASSERT (errno == EINVAL);
270 ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, -1) == -1);
271 ASSERT (errno == EINVAL);
273 ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, bad_fd) == -1);
274 ASSERT (errno == EINVAL
275 || errno == EMFILE /* WSL */);
277 /* For F_DUPFD*, check for correct inheritance, as well as
278 preservation of text vs. binary. */
279 set_binary_mode (fd, O_BINARY);
280 ASSERT (is_open (fd));
281 ASSERT (!is_open (fd + 1));
282 ASSERT (!is_open (fd + 2));
283 ASSERT (is_inheritable (fd));
284 ASSERT (is_mode (fd, O_BINARY));
286 ASSERT (fcntl (fd, F_DUPFD, fd) == fd + 1);
287 ASSERT (is_open (fd));
288 ASSERT (is_open (fd + 1));
289 ASSERT (!is_open (fd + 2));
290 ASSERT (is_inheritable (fd + 1));
291 ASSERT (is_mode (fd, O_BINARY));
292 ASSERT (is_mode (fd + 1, O_BINARY));
293 ASSERT (close (fd + 1) == 0);
295 ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, fd + 2) == fd + 2);
296 ASSERT (is_open (fd));
297 ASSERT (!is_open (fd + 1));
298 ASSERT (is_open (fd + 2));
299 ASSERT (is_inheritable (fd));
300 ASSERT (!is_inheritable (fd + 2));
301 ASSERT (is_mode (fd, O_BINARY));
302 ASSERT (is_mode (fd + 2, O_BINARY));
303 ASSERT (close (fd) == 0);
305 set_binary_mode (fd + 2, O_TEXT);
306 ASSERT (fcntl (fd + 2, F_DUPFD, fd + 1) == fd + 1);
307 ASSERT (!is_open (fd));
308 ASSERT (is_open (fd + 1));
309 ASSERT (is_open (fd + 2));
310 ASSERT (is_inheritable (fd + 1));
311 ASSERT (!is_inheritable (fd + 2));
312 ASSERT (is_mode (fd + 1, O_TEXT));
313 ASSERT (is_mode (fd + 2, O_TEXT));
314 ASSERT (close (fd + 1) == 0);
316 ASSERT (fcntl (fd + 2, F_DUPFD_CLOEXEC, 0) == fd);
317 ASSERT (is_open (fd));
318 ASSERT (!is_open (fd + 1));
319 ASSERT (is_open (fd + 2));
320 ASSERT (!is_inheritable (fd));
321 ASSERT (!is_inheritable (fd + 2));
322 ASSERT (is_mode (fd, O_TEXT));
323 ASSERT (is_mode (fd + 2, O_TEXT));
324 ASSERT (close (fd + 2) == 0);
326 /* Test F_GETFD on invalid file descriptors. */
328 ASSERT (fcntl (-1, F_GETFD) == -1);
329 ASSERT (errno == EBADF);
331 ASSERT (fcntl (fd + 1, F_GETFD) == -1);
332 ASSERT (errno == EBADF);
334 ASSERT (fcntl (bad_fd, F_GETFD) == -1);
335 ASSERT (errno == EBADF);
337 /* Test F_GETFD, the FD_CLOEXEC bit. */
339 int result = fcntl (fd, F_GETFD);
340 ASSERT (0 <= result);
341 ASSERT ((result & FD_CLOEXEC) == FD_CLOEXEC);
342 ASSERT (dup (fd) == fd + 1);
343 result = fcntl (fd + 1, F_GETFD);
344 ASSERT (0 <= result);
345 ASSERT ((result & FD_CLOEXEC) == 0);
346 ASSERT (close (fd + 1) == 0);
350 /* Test F_SETFD on invalid file descriptors. */
352 ASSERT (fcntl (-1, F_SETFD, 0) == -1);
353 ASSERT (errno == EBADF);
355 ASSERT (fcntl (fd + 1, F_SETFD, 0) == -1);
356 ASSERT (errno == EBADF);
358 ASSERT (fcntl (bad_fd, F_SETFD, 0) == -1);
359 ASSERT (errno == EBADF);
363 /* Test F_GETFL on invalid file descriptors. */
365 ASSERT (fcntl (-1, F_GETFL) == -1);
366 ASSERT (errno == EBADF);
368 ASSERT (fcntl (fd + 1, F_GETFL) == -1);
369 ASSERT (errno == EBADF);
371 ASSERT (fcntl (bad_fd, F_GETFL) == -1);
372 ASSERT (errno == EBADF);
376 /* Test F_SETFL on invalid file descriptors. */
378 ASSERT (fcntl (-1, F_SETFL, 0) == -1);
379 ASSERT (errno == EBADF);
381 ASSERT (fcntl (fd + 1, F_SETFL, 0) == -1);
382 ASSERT (errno == EBADF);
384 ASSERT (fcntl (bad_fd, F_SETFL, 0) == -1);
385 ASSERT (errno == EBADF);
389 /* Test F_GETOWN on invalid file descriptors. */
391 ASSERT (fcntl (-1, F_GETOWN) == -1);
392 ASSERT (errno == EBADF);
394 ASSERT (fcntl (fd + 1, F_GETOWN) == -1);
395 ASSERT (errno == EBADF);
397 ASSERT (fcntl (bad_fd, F_GETOWN) == -1);
398 ASSERT (errno == EBADF);
402 /* Test F_SETFL on invalid file descriptors. */
404 ASSERT (fcntl (-1, F_SETOWN, 0) == -1);
405 ASSERT (errno == EBADF);
407 ASSERT (fcntl (fd + 1, F_SETOWN, 0) == -1);
408 ASSERT (errno == EBADF);
410 ASSERT (fcntl (bad_fd, F_SETOWN, 0) == -1);
411 ASSERT (errno == EBADF);
415 ASSERT (close (fd) == 0);
416 ASSERT (unlink (file) == 0);
418 /* Close file descriptors that may have been inherited from the parent
419 process and that would cause failures below.
420 Such file descriptors have been seen:
421 - with GNU make, when invoked as 'make -j N' with j > 1,
422 - in some versions of the KDE desktop environment,
424 - in MacPorts with the "trace mode" enabled.
428 /* Test whether F_DUPFD_CLOEXEC is effective. */
429 ASSERT (fcntl (1, F_DUPFD_CLOEXEC, 10) >= 0);
430 #if defined _WIN32 && !defined __CYGWIN__
431 return _execl ("./test-fcntl", "./test-fcntl", "child", NULL);
433 return execl ("./test-fcntl", "./test-fcntl", "child", NULL);