glibc/sysdeps/unix/sysv/linux/i386/seteuid.c

61 lines
1.7 KiB
C

/* Copyright (C) 1998, 2000, 2002, 2003, 2004 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <unistd.h>
#include <setxid.h>
#include "kernel-features.h"
#ifdef __NR_setresuid
extern int __setresuid (uid_t ruid, uid_t euid, uid_t suid);
#endif
int
seteuid (uid_t uid)
{
int result;
if (uid == (uid_t) ~0)
{
__set_errno (EINVAL);
return -1;
}
#if __ASSUME_32BITUIDS > 0
result = INLINE_SETXID_SYSCALL (setresuid32, 3, -1, uid, -1);
#else
/* First try the syscall. */
# ifdef __NR_setresuid
result = __setresuid (-1, uid, -1);
# if __ASSUME_SETRESUID_SYSCALL > 0
if (0)
# else
if (result == -1 && errno == ENOSYS)
# endif
/* No system call available. Use emulation. This may not work
since `setreuid' also sets the saved user ID when UID is not
equal to the real user ID, making it impossible to switch back. */
# endif
result = __setreuid (-1, uid);
#endif
return result;
}
libc_hidden_def (seteuid)