sysdeps/unix/sysv/linux/i386/fchown.c

   1 /* Copyright (C) 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21
  22 #include <sysdep.h>
  23 #include <sys/syscall.h>
  24
  25 #include <linux/posix_types.h>
  26 #include "kernel-features.h"
  27
  28 extern int __syscall_fchown (int __fd,
  29                              __kernel_uid_t __owner, __kernel_gid_t __group);
  30
  31 #ifdef __NR_fchown32
  32 extern int __syscall_fchown32 (int __fd,
  33                                __kernel_uid32_t __owner, __kernel_gid32_t __group);
  34 # if __ASSUME_32BITUIDS == 0
  35 /* This variable is shared with all files that need to check for 32bit
  36    uids.  */
  37 extern int __libc_missing_32bit_uids;
  38 # endif
  39 #endif /* __NR_fchown32 */
  40
  41 int
  42 __fchown (int fd, uid_t owner, gid_t group)
  43 {
  44 #if  __ASSUME_32BITUIDS > 0
  45   return INLINE_SYSCALL (fchown32, 3, fd, owner, group);
  46 #else
  47 # ifdef __NR_fchown32
  48   if (__libc_missing_32bit_uids <= 0)
  49     {
  50       int result;
  51       int saved_errno = errno;
  52
  53       result = INLINE_SYSCALL (fchown32, 3, fd, owner, group);
  54       if (result == 0 || errno != ENOSYS)
  55         return result;
  56
  57       __set_errno (saved_errno);
  58       __libc_missing_32bit_uids = 1;
  59     }
  60 # endif /* __NR_fchown32 */
  61
  62   if (((owner + 1) > (uid_t) ((__kernel_uid_t) -1U))
  63       || ((group + 1) > (gid_t) ((__kernel_gid_t) -1U)))
  64     {
  65       __set_errno (EINVAL);
  66       return -1;
  67     }
  68
  69   return INLINE_SYSCALL (fchown, 3, fd, owner, group);
  70 #endif
  71 }
  72
  73 weak_alias (__fchown, fchown)