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 
10 USE_CHROOT(NEWTOY(chroot, "^<1", TOYFLAG_USR|TOYFLAG_SBIN|TOYFLAG_ARGFAIL(125)))
11 
12 config 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 
23 void 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