LXR toybox/toys/other/chroot.c

   1/* chroot.c - Run command in new root directory.
   2 *
   3 * Copyright 2007 Rob Landley <rob@landley.net>
   4 *
   5 * TODO: The test for root is "==" so root can trivially escape a chroot by
   6 * moving it below cwd, ala mkdir("sub"); chroot("sub"); chdir("../../../..")
   7 * The container guys use pivot_root() to deal with this, which does actually
   8 * edit mount tree. (New option? Kernel patch?)
   9
  10USE_CHROOT(NEWTOY(chroot, "^<1", TOYFLAG_USR|TOYFLAG_SBIN|TOYFLAG_ARGFAIL(125)))
  11
  12config CHROOT
  13  bool "chroot"
  14  default y
  15  help
  16    usage: chroot NEWROOT [COMMAND [ARG...]]
  17
  18    Run command within a new root directory. If no command, run /bin/sh.
  19*/
  20
  21#include "toys.h"
  22
  23void chroot_main(void)
  24{
  25  char *binsh[] = {"/bin/sh", "-i", 0};
  26
  27  if (chdir(*toys.optargs) || chroot(".")) {
  28    toys.exitval = 125;
  29    perror_exit_raw(*toys.optargs);
  30  }
  31  if (toys.optargs[1]) xexec(toys.optargs+1);
  32  else xexec(binsh);
  33}
  34