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

56 lines
1.7 KiB
C

/* Copyright (C) 1998, 1999 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include "kernel-features.h"
#if defined __NR_setresuid || __ASSUME_SETRESUID_SYSCALL > 0
extern int __setresuid (uid_t ruid, uid_t euid, uid_t suid);
int
seteuid (uid_t uid)
{
int result;
if (uid == (uid_t) ~0)
{
__set_errno (EINVAL);
return -1;
}
/* First try the syscall. */
result = __setresuid (-1, uid, -1);
# if __ASSUME_SETRESUID_SYSCALL == 0
if (result == -1 && errno == ENOSYS)
/* 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. */
result = __setreuid (-1, uid);
# endif
return result;
}
#else
# include <sysdeps/unix/bsd/seteuid.c>
#endif