Let fcntl do the work, instead of copying code into other modules.
* modules/cloexec (Depends-on): Add fcntl.
* modules/fchdir (Depends-on): Likewise.
* modules/fd-safer-flag (Depends-on): Likewise.
* modules/unistd-safer (Depends-on): Likewise.
* modules/dup3 (configure.ac): Set module indicator.
* m4/fchdir.m4 (gl_FUNC_FCHDIR): Replace fcntl if fchdir is
missing.
* lib/fchdir.c (_gl_register_dup): Fix comment.
* lib/cloexec.c (dup_cloexec): Simplify, by relying on fcntl.
* lib/dup-safer.c (dup_safer): Likewise.
* lib/dup-safer-flag.c (dup_safer_flag): Likewise.
* lib/dup3.c (dup3): Likewise.
* tests/test-fchdir.c (main): Enhance test.
Fixes a dup_cloexec bug reported by Ondřej Vašík.
Signed-off-by: Eric Blake <ebb9@byu.net>
2009-12-16 Eric Blake <ebb9@byu.net>
+ fcntl: use to simplify other modules
+ * modules/cloexec (Depends-on): Add fcntl.
+ * modules/fchdir (Depends-on): Likewise.
+ * modules/fd-safer-flag (Depends-on): Likewise.
+ * modules/unistd-safer (Depends-on): Likewise.
+ * modules/dup3 (configure.ac): Set module indicator.
+ * m4/fchdir.m4 (gl_FUNC_FCHDIR): Replace fcntl if fchdir is
+ missing.
+ * lib/fchdir.c (_gl_register_dup): Fix comment.
+ * lib/cloexec.c (dup_cloexec): Simplify, by relying on fcntl.
+ * lib/dup-safer.c (dup_safer): Likewise.
+ * lib/dup-safer-flag.c (dup_safer_flag): Likewise.
+ * lib/dup3.c (dup3): Likewise.
+ * tests/test-fchdir.c (main): Enhance test.
+ Fixes a dup_cloexec bug reported by Ondřej Vašík.
+
fcntl: port portions of fcntl to mingw
* m4/fcntl.m4 (gl_FUNC_FCNTL): Also build fcntl.c on mingw.
* lib/fcntl.c (fcntl) <F_DUPFD, F_DUPFD_CLOEXEC, F_GETFD>: Provide
#include <fcntl.h>
#include <unistd.h>
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-/* Native Woe32 API. */
-# define WIN32_LEAN_AND_MEAN
-# include <windows.h>
-# include <io.h>
-#endif
-
-
/* Set the `FD_CLOEXEC' flag of DESC if VALUE is true,
or clear the flag if VALUE is false.
Return 0 on success, or -1 on error with `errno' set.
int
set_cloexec_flag (int desc, bool value)
{
-#if defined F_GETFD && defined F_SETFD
+#ifdef F_SETFD
int flags = fcntl (desc, F_GETFD, 0);
return -1;
-#else
+#else /* !F_SETFD */
/* Use dup2 to reject invalid file descriptors; the cloexec flag
will be unaffected. */
/* There is nothing we can do on this kind of platform. Punt. */
return 0;
-#endif
+#endif /* !F_SETFD */
}
int
dup_cloexec (int fd)
{
- int nfd;
-
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-
- /* Native Woe32 API. */
- HANDLE curr_process = GetCurrentProcess ();
- HANDLE old_handle = (HANDLE) _get_osfhandle (fd);
- HANDLE new_handle;
- int mode;
-
- if (old_handle == INVALID_HANDLE_VALUE
- || (mode = setmode (fd, O_BINARY)) == -1)
- {
- /* fd is closed, or is open to no handle at all.
- We cannot duplicate fd in this case, because _open_osfhandle
- fails for an INVALID_HANDLE_VALUE argument. */
- errno = EBADF;
- return -1;
- }
- setmode (fd, mode);
-
- if (!DuplicateHandle (curr_process, /* SourceProcessHandle */
- old_handle, /* SourceHandle */
- curr_process, /* TargetProcessHandle */
- (PHANDLE) &new_handle, /* TargetHandle */
- (DWORD) 0, /* DesiredAccess */
- FALSE, /* InheritHandle */
- DUPLICATE_SAME_ACCESS)) /* Options */
- {
- /* TODO: Translate GetLastError () into errno. */
- errno = EMFILE;
- return -1;
- }
-
- nfd = _open_osfhandle ((long) new_handle, mode | O_NOINHERIT);
- if (nfd < 0)
- {
- CloseHandle (new_handle);
- errno = EMFILE;
- return -1;
- }
-
-# if REPLACE_FCHDIR
- if (0 <= nfd)
- nfd = _gl_register_dup (fd, nfd);
-# endif
- return nfd;
-
-#else /* !_WIN32 */
-
- /* Unix API. */
-
-# ifdef F_DUPFD_CLOEXEC
- nfd = fcntl (fd, F_DUPFD_CLOEXEC, 0);
-# if REPLACE_FCHDIR
- if (0 <= nfd)
- nfd = _gl_register_dup (fd, nfd);
-# endif
-
-# else /* !F_DUPFD_CLOEXEC */
- nfd = dup (fd);
- if (0 <= nfd && set_cloexec_flag (nfd, true) < 0)
- {
- int saved_errno = errno;
- close (nfd);
- nfd = -1;
- errno = saved_errno;
- }
-# endif /* !F_DUPFD_CLOEXEC */
-
- return nfd;
-
-#endif /* !_WIN32 */
+ return fcntl (fd, F_DUPFD_CLOEXEC, 0);
}
int
dup_safer_flag (int fd, int flag)
{
- if (flag & O_CLOEXEC)
- {
-#if defined F_DUPFD_CLOEXEC && !REPLACE_FCHDIR
- return fcntl (fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
-#else
- /* fd_safer_flag calls us back, but eventually the recursion
- unwinds and does the right thing. */
- fd = dup_cloexec (fd);
- return fd_safer_flag (fd, flag);
-#endif
- }
- return dup_safer (fd);
+ return fcntl (fd, (flag & O_CLOEXEC) ? F_DUPFD_CLOEXEC : F_DUPFD,
+ STDERR_FILENO + 1);
}
int
dup_safer (int fd)
{
-#if defined F_DUPFD && !REPLACE_FCHDIR
return fcntl (fd, F_DUPFD, STDERR_FILENO + 1);
-#else
- /* fd_safer calls us back, but eventually the recursion unwinds and
- does the right thing. */
- return fd_safer (dup (fd));
-#endif
}
}
#endif
- if (oldfd < 0 || newfd < 0 || newfd >= getdtablesize ())
+ if (newfd < 0 || newfd >= getdtablesize () || fcntl (oldfd, F_GETFD) == -1)
{
errno = EBADF;
return -1;
return -1;
}
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-/* Native Woe32 API. */
-
if (flags & O_CLOEXEC)
{
- /* Neither dup() nor dup2() can create a file descriptor with
- O_CLOEXEC = O_NOINHERIT set. We need to use the low-level function
- _open_osfhandle for this. Iterate until all file descriptors less
- than newfd are filled up. */
- HANDLE curr_process = GetCurrentProcess ();
- HANDLE old_handle = (HANDLE) _get_osfhandle (oldfd);
- unsigned char fds_to_close[OPEN_MAX_MAX / CHAR_BIT];
- unsigned int fds_to_close_bound = 0;
int result;
-
- if (old_handle == INVALID_HANDLE_VALUE)
- {
- /* oldfd is not open, or is an unassigned standard file
- descriptor. */
- errno = EBADF;
- return -1;
- }
-
close (newfd);
-
- for (;;)
+ result = fcntl (oldfd, F_DUPFD_CLOEXEC, newfd);
+ if (newfd < result)
{
- HANDLE new_handle;
- int duplicated_fd;
- unsigned int index;
-
- if (!DuplicateHandle (curr_process, /* SourceProcessHandle */
- old_handle, /* SourceHandle */
- curr_process, /* TargetProcessHandle */
- (PHANDLE) &new_handle, /* TargetHandle */
- (DWORD) 0, /* DesiredAccess */
- FALSE, /* InheritHandle */
- DUPLICATE_SAME_ACCESS)) /* Options */
- {
- errno = EBADF; /* arbitrary */
- result = -1;
- break;
- }
- duplicated_fd = _open_osfhandle ((long) new_handle, flags);
- if (duplicated_fd < 0)
- {
- CloseHandle (new_handle);
- result = -1;
- break;
- }
- if (duplicated_fd > newfd)
- /* Shouldn't happen, since newfd is still closed. */
- abort ();
- if (duplicated_fd == newfd)
- {
- result = newfd;
- break;
- }
-
- /* Set the bit duplicated_fd in fds_to_close[]. */
- index = (unsigned int) duplicated_fd / CHAR_BIT;
- if (index >= fds_to_close_bound)
- {
- if (index >= sizeof (fds_to_close))
- /* Need to increase OPEN_MAX_MAX. */
- abort ();
- memset (fds_to_close + fds_to_close_bound, '\0',
- index + 1 - fds_to_close_bound);
- fds_to_close_bound = index + 1;
- }
- fds_to_close[index] |= 1 << ((unsigned int) duplicated_fd % CHAR_BIT);
+ close (result);
+ errno = EIO;
+ result = -1;
}
-
- /* Close the previous fds that turned out to be too small. */
- {
- int saved_errno = errno;
- unsigned int duplicated_fd;
-
- for (duplicated_fd = 0;
- duplicated_fd < fds_to_close_bound * CHAR_BIT;
- duplicated_fd++)
- if ((fds_to_close[duplicated_fd / CHAR_BIT]
- >> (duplicated_fd % CHAR_BIT))
- & 1)
- close (duplicated_fd);
-
- errno = saved_errno;
- }
-
-#if REPLACE_FCHDIR
- if (result == newfd)
- result = _gl_register_dup (oldfd, newfd);
-#endif
- return result;
+ if (result < 0)
+ return -1;
}
-
- if (dup2 (oldfd, newfd) < 0)
- return -1;
-
-#else
-/* Unix API. */
-
- if (dup2 (oldfd, newfd) < 0)
+ else if (dup2 (oldfd, newfd) < 0)
return -1;
- /* POSIX <http://www.opengroup.org/onlinepubs/9699919799/functions/dup.html>
- says that initially, the FD_CLOEXEC flag is cleared on newfd. */
-
- if (flags & O_CLOEXEC)
- {
- int fcntl_flags;
-
- if ((fcntl_flags = fcntl (newfd, F_GETFD, 0)) < 0
- || fcntl (newfd, F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
- {
- int saved_errno = errno;
- close (newfd);
- errno = saved_errno;
- return -1;
- }
- }
-
-#endif
-
#if O_BINARY
if (flags & O_BINARY)
setmode (newfd, O_BINARY);
setmode (newfd, O_TEXT);
#endif
-#if REPLACE_FCHDIR
- newfd = _gl_register_dup (oldfd, newfd);
-#endif
return newfd;
}
and fcntl. Both arguments must be valid and distinct file
descriptors. Close NEWFD and return -1 if OLDFD is tracking a
directory, but there is insufficient memory to track the same
- directory in NEWFD; otherwise return NEWFD.
-
- FIXME: Need to implement rpl_fcntl in gnulib, and have it call
- this. */
+ directory in NEWFD; otherwise return NEWFD. */
int
_gl_register_dup (int oldfd, int newfd)
{
-# fchdir.m4 serial 12
+# fchdir.m4 serial 13
dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
gl_REPLACE_CLOSE
gl_REPLACE_DUP2
dnl dup3 is already unconditionally replaced
+ gl_REPLACE_FCNTL
gl_REPLACE_DIRENT_H
AC_CACHE_CHECK([whether open can visit directories],
[gl_cv_func_open_directory_works],
Depends-on:
dup2
+fcntl
stdbool
configure.ac:
configure.ac:
gl_FUNC_DUP3
+gl_MODULE_INDICATOR([dup3])
gl_UNISTD_MODULE_INDICATOR([dup3])
Makefile.am:
dirent
dirfd
dup2
+fcntl
fcntl-h
include_next
malloc-posix
lib/dup-safer-flag.c
Depends-on:
-unistd-safer
cloexec
+fcntl
+unistd-safer
configure.ac:
gl_MODULE_INDICATOR([fd-safer-flag])
m4/unistd-safer.m4
Depends-on:
+fcntl
unistd
configure.ac:
ASSERT (dup_cloexec (fd) == new_fd);
ASSERT (dup2 (new_fd, fd) == fd);
ASSERT (close (new_fd) == 0);
+ ASSERT (fcntl (fd, F_DUPFD_CLOEXEC, new_fd) == new_fd);
+ ASSERT (close (fd) == 0);
+ ASSERT (fcntl (new_fd, F_DUPFD, fd) == fd);
+ ASSERT (close (new_fd) == 0);
+#if GNULIB_DUP3
+ ASSERT (dup3 (fd, new_fd, 0) == new_fd);
+ ASSERT (dup3 (new_fd, fd, 0) == fd);
+ ASSERT (close (new_fd) == 0);
+#endif
}
}
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