Mercurial > gnulib
view lib/chdir-safer.c @ 17363:5a51fb7777a9
sys_select, sys_time: port 2013-01-30 Solaris 2.6 fix to Cygwin
Problem reported by Marco Atzeri in
<http://lists.gnu.org/archive/html/bug-gnulib/2013-03/msg00000.html>.
* lib/sys_select.in.h [HAVE_SYS_SELECT_H && _CYGWIN_SYS_TIME_H]:
Simply delegate to the system <sys/select.h> in this case too.
Also, pay attention to _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H only
if OSF/1, since otherwise Cygwin breaks, and it doesn't seem to
be needed on Solaris either.
* lib/sys_time.in.h [_CYGWIN_SYS_TIME_H]:
Simply delgate to the system <sys/time.h> in this case.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Tue, 19 Mar 2013 09:08:47 -0700 |
parents | e542fd46ad6f |
children | 344018b6e5d7 |
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/* much like chdir(2), but safer Copyright (C) 2005-2006, 2008-2013 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* written by Jim Meyering */ #include <config.h> #include "chdir-safer.h" #include <stdbool.h> #include <fcntl.h> #include <errno.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include "same-inode.h" #ifndef HAVE_READLINK # define HAVE_READLINK 0 #endif /* Like chdir, but fail if DIR is a symbolic link to a directory (or similar funny business). This avoids a minor race condition between when a directory is created or statted and when the process chdirs into it. On older systems lacking full support for O_SEARCH, this function can also fail if DIR is not readable. */ int chdir_no_follow (char const *dir) { int result = 0; int saved_errno; int fd = open (dir, O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK); if (fd < 0) return -1; /* If open follows symlinks, lstat DIR and fstat FD to ensure that they are the same file; if they are different files, set errno to ELOOP (the same value that open uses for symlinks with O_NOFOLLOW) so the caller can report a failure. Skip this check if HAVE_READLINK == 0, which should be the case on any system that lacks symlink support. */ if (HAVE_READLINK && ! HAVE_WORKING_O_NOFOLLOW) { struct stat sb1; result = lstat (dir, &sb1); if (result == 0) { struct stat sb2; result = fstat (fd, &sb2); if (result == 0 && ! SAME_INODE (sb1, sb2)) { errno = ELOOP; result = -1; } } } if (result == 0) result = fchdir (fd); saved_errno = errno; close (fd); errno = saved_errno; return result; }