glibc/sysdeps/mach/hurd/chroot.c

66 lines
2.0 KiB
C

/* Copyright (C) 1991-2017 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 <string.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/port.h>
/* Make PATH be the root directory (the starting point for absolute
paths). Note that while on traditional UNIX systems this call is
restricted to the super-user, it isn't on the Hurd. */
int
chroot (const char *path)
{
const char *lookup;
size_t len;
file_t dir, root;
error_t err;
/* Append trailing "/." to directory name to force ENOTDIR if it's not a
directory and EACCES if we don't have search permission. */
len = strlen (path);
if (len >= 2 && path[len - 2] == '/' && path[len - 1] == '.')
lookup = path;
else if (len == 0)
/* Special-case empty file name according to POSIX. */
return __hurd_fail (ENOENT);
else
{
char *n = alloca (len + 3);
memcpy (n, path, len);
n[len] = '/';
n[len + 1] = '.';
n[len + 2] = '\0';
lookup = n;
}
dir = __file_name_lookup (lookup, 0, 0);
if (dir == MACH_PORT_NULL)
return -1;
/* Prevent going through DIR's .. */
err = __file_reparent (dir, MACH_PORT_NULL, &root);
__mach_port_deallocate (__mach_task_self (), dir);
if (err)
return __hurd_fail (err);
_hurd_port_set (&_hurd_ports[INIT_PORT_CRDIR], root);
return 0;
}