glibc/sysdeps/unix/sysv/linux/i386/getgroups.c
2012-02-09 23:18:22 +00:00

82 lines
2.2 KiB
C

/* Copyright (C) 1997, 1998, 2000, 2001, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include <bp-checks.h>
#include <linux/posix_types.h>
#include <kernel-features.h>
#ifdef __NR_getgroups32
# if __ASSUME_32BITUIDS == 0
/* This variable is shared with all files that need to check for 32bit
uids. */
extern int __libc_missing_32bit_uids attribute_hidden;
# endif
#endif /* __NR_getgroups32 */
/* For Linux we must convert the array of groups from the format that the
kernel returns. */
int
__getgroups (int n, gid_t *groups)
{
#if __ASSUME_32BITUIDS > 0
return INLINE_SYSCALL (getgroups32, 2, n, CHECK_N (groups, n));
#else
if (__builtin_expect (n, 1) < 0)
{
__set_errno (EINVAL);
return -1;
}
else
{
# ifdef __NR_getgroups32
if (__libc_missing_32bit_uids <= 0)
{
int result;
int saved_errno = errno;
result = INLINE_SYSCALL (getgroups32, 2, n, CHECK_N (groups, n));
if (result != -1 || errno != ENOSYS)
return result;
__set_errno (saved_errno);
__libc_missing_32bit_uids = 1;
}
# endif /* __NR_getgroups32 */
int i, ngids;
__kernel_gid_t kernel_groups[n = MIN (n, __sysconf (_SC_NGROUPS_MAX))];
ngids = INLINE_SYSCALL (getgroups, 2, n, CHECK_N (kernel_groups, n));
if (n != 0 && ngids > 0)
for (i = 0; i < ngids; i++)
(__ptrvalue (groups))[i] = kernel_groups[i];
return ngids;
}
#endif
}
weak_alias (__getgroups, getgroups)