kc3-lang/gnulib/lib/chdir-safer.c

• Show log

  Commit

• Hash : 0632e115
  Author :
  Date : 2006-09-13T22:38:14
  

  * _fpending.c: Include <config.h> unconditionally, since we no
  longer worry about uses that don't define HAVE_CONFIG_H.
  * acl.c, alloca.c, argmatch.c, atexit.c, backupfile.c:
  * basename.c, c-stack.c, c-strtod.c, calloc.c, canon-host.c:
  * canonicalize.c, chdir-long.c, chdir-safer.c, chown.c:
  * cloexec.c, close-stream.c, closeout.c, creat-safer.c:
  * cycle-check.c, diacrit.c, dirchownmod.c, dirfd.c, dirname.c:
  * dup-safer.c, dup2.c, error.c, euidaccess.c, exclude.c:
  * exitfail.c, fchmodat.c, fchown-stub.c, fd-safer.c:
  * file-type.c, fileblocks.c, filemode.c, filenamecat.c:
  * fnmatch.c, fopen-safer.c, fprintftime.c, free.c, fsusage.c:
  * ftruncate.c, fts-cycle.c, fts.c, full-write.c, gai_strerror.c:
  * getcwd.c, getdate.y, getdomainname.c, getgroups.c:
  * gethostname.c, gethrxtime.c, getloadavg.c, getlogin_r.c:
  * getndelim2.c, getnline.c, getopt.c, getopt1.c, getpass.c:
  * gettime.c, gettimeofday.c, getugroups.c, getusershell.c:
  * glob.c, group-member.c, hard-locale.c, hash-pjw.c, hash.c:
  * human.c, idcache.c, inet_ntop.c, inet_pton.c, inttostr.c:
  * isdir.c, lchown.c, linebuffer.c, long-options.c, lstat.c:
  * malloc.c, md5.c, memcasecmp.c, memchr.c, memcmp.c, memcoll.c:
  * memcpy.c, memmove.c, memrchr.c, mkancesdirs.c, mkdir-p.c:
  * mkdir.c, mkdirat.c, mkstemp-safer.c, mkstemp.c, modechange.c:
  * mountlist.c, nanosleep.c, obstack.c, open-safer.c:
  * openat-die.c, openat.c, pagealign_alloc.c, physmem.c:
  * pipe-safer.c, posixtm.c, posixver.c, putenv.c, quote.c:
  * quotearg.c, raise.c, readtokens.c, readtokens0.c, readutmp.c:
  * realloc.c, regex.c, rename.c, rmdir.c, rpmatch.c, safe-read.c:
  * same.c, save-cwd.c, savedir.c, setenv.c, settime.c, sha1.c:
  * sig2str.c, snprintf.c, strdup.c, strerror.c, strftime.c:
  * stripslash.c, strndup.c, strnlen.c, strpbrk.c, strtod.c:
  * strtoimax.c, strtol.c, strverscmp.c, tempname.c, time_r.c:
  * timegm.c, tmpfile-safer.c, unlinkdir.c, userspec.c, utime.c:
  * utimecmp.c, utimens.c, version-etc-fsf.c, version-etc.c:
  * xalloc-die.c, xgetcwd.c, xgethostname.c, xmalloc.c:
  * xmemcoll.c, xnanosleep.c, xreadlink.c, xstrtod.c:
  * xstrtoimax.c, xstrtol.c, xstrtoumax.c, yesno.c:
  Likewise.
  

Download

• lib/chdir-safer.c

• /* much like chdir(2), but safer
  
     Copyright (C) 2005, 2006 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 2, 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, write to the Free Software Foundation,
     Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  
  /* 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"
  
  /* Like chdir, but fail if DIR is a symbolic link to a directory (or
     similar funny business), or if DIR is not readable.  This avoids a
     minor race condition between when a directory is created or statted
     and when the process chdirs into it.  */
  int
  chdir_no_follow (char const *dir)
  {
    int result = 0;
    int saved_errno;
    int fd = open (dir,
  		 O_RDONLY | 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.  */
    if (! 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;
  }
  

Download