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

   1 /* Copyright (C) 1997,1998,2000,2002,2004,2006 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 <grp.h>
  21 #include <unistd.h>
  22 #include <sys/types.h>
  23
  24 #include <sysdep.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.h>
  27
  28 #include <linux/posix_types.h>
  29 #include <kernel-features.h>
  30
  31
  32 #ifdef __NR_setgroups32
  33 # if __ASSUME_32BITUIDS == 0
  34 /* This variable is shared with all files that need to check for 32bit
  35    uids.  */
  36 extern int __libc_missing_32bit_uids;
  37 # endif
  38 #endif /* __NR_setgroups32 */
  39
  40 /* Set the group set for the current user to GROUPS (N of them).  For
  41    Linux we must convert the array of groups into the format that the
  42    kernel expects.  */
  43 int
  44 setgroups (size_t n, const gid_t *groups)
  45 {
  46 #if __ASSUME_32BITUIDS > 0
  47   return INLINE_SYSCALL (setgroups32, 2, n, CHECK_N (groups, n));
  48 #else
  49   if (n > (size_t) __sysconf (_SC_NGROUPS_MAX))
  50     {
  51       __set_errno (EINVAL);
  52       return -1;
  53     }
  54   else
  55     {
  56       size_t i;
  57       __kernel_gid_t kernel_groups[n];
  58
  59 # ifdef __NR_setgroups32
  60       if (__libc_missing_32bit_uids <= 0)
  61         {
  62           int result;
  63           int saved_errno = errno;
  64
  65           result = INLINE_SYSCALL (setgroups32, 2, n, CHECK_N (groups, n));
  66           if (result == 0 || errno != ENOSYS)
  67             return result;
  68
  69           __set_errno (saved_errno);
  70           __libc_missing_32bit_uids = 1;
  71         }
  72 # endif /* __NR_setgroups32 */
  73       for (i = 0; i < n; i++)
  74         {
  75           kernel_groups[i] = (__ptrvalue (groups))[i];
  76           if (groups[i] != (gid_t) ((__kernel_gid_t) groups[i]))
  77             {
  78               __set_errno (EINVAL);
  79               return -1;
  80             }
  81         }
  82
  83       return INLINE_SYSCALL (setgroups, 2, n, CHECK_N (kernel_groups, n));
  84     }
  85 #endif
  86 }
  87 libc_hidden_def (setgroups)