LXR busybox/coreutils/chroot.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Mini chroot implementation for busybox
   4 *
   5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8 */
   9//config:config CHROOT
  10//config:       bool "chroot (3.7 kb)"
  11//config:       default y
  12//config:       help
  13//config:       chroot is used to change the root directory and run a command.
  14//config:       The default command is '/bin/sh'.
  15
  16//applet:IF_CHROOT(APPLET_NOEXEC(chroot, chroot, BB_DIR_USR_SBIN, BB_SUID_DROP, chroot))
  17
  18//kbuild:lib-$(CONFIG_CHROOT) += chroot.o
  19
  20/* BB_AUDIT SUSv3 N/A -- Matches GNU behavior. */
  21
  22//usage:#define chroot_trivial_usage
  23//usage:       "NEWROOT [PROG ARGS]"
  24//usage:#define chroot_full_usage "\n\n"
  25//usage:       "Run PROG with root directory set to NEWROOT"
  26//usage:
  27//usage:#define chroot_example_usage
  28//usage:       "$ ls -l /bin/ls\n"
  29//usage:       "lrwxrwxrwx    1 root     root          12 Apr 13 00:46 /bin/ls -> /BusyBox\n"
  30//usage:       "# mount /dev/hdc1 /mnt -t minix\n"
  31//usage:       "# chroot /mnt\n"
  32//usage:       "# ls -l /bin/ls\n"
  33//usage:       "-rwxr-xr-x    1 root     root        40816 Feb  5 07:45 /bin/ls*\n"
  34
  35#include "libbb.h"
  36
  37int chroot_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  38int chroot_main(int argc UNUSED_PARAM, char **argv)
  39{
  40        ++argv;
  41        if (!*argv)
  42                bb_show_usage();
  43
  44        xchroot(*argv);
  45
  46        ++argv;
  47        if (!*argv) { /* no 2nd param (PROG), use shell */
  48                argv -= 2;
  49                argv[0] = (char *) get_shell_name();
  50                argv[1] = (char *) "-i"; /* GNU coreutils 8.4 compat */
  51                /*argv[2] = NULL; - already is */
  52        }
  53
  54        BB_EXECVP_or_die(argv);
  55}
  56