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/*
* SPDX-FileCopyrightText: 2011 , Julian Pidancet
* SPDX-FileCopyrightText: 2011 , Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <stdio.h>
#include <assert.h>
#include "defines.h"
#include "prototypes.h"
/*@-exitarg@*/
#include "exitcodes.h"
#include "shadowlog.h"
static void change_root (const char* newroot);
/*
* process_root_flag - chroot if given the --root option
*
* This shall be called before accessing the passwd, group, shadow,
* gshadow, useradd's default, login.defs files (non exhaustive list)
* or authenticating the caller.
*
* The audit, syslog, or locale files shall be open before
*/
extern void process_root_flag (const char* short_opt, int argc, char **argv)
{
/*
* Parse the command line options.
*/
int i;
const char *newroot = NULL, *val;
for (i = 0; i < argc; i++) {
val = NULL;
if ( (strcmp (argv[i], "--root") == 0)
|| ((strncmp (argv[i], "--root=", 7) == 0)
&& (val = argv[i] + 7))
|| (strcmp (argv[i], short_opt) == 0)) {
if (NULL != newroot) {
fprintf (log_get_logfd(),
_("%s: multiple --root options\n"),
log_get_progname());
exit (E_BAD_ARG);
}
if (val) {
newroot = val;
} else if (i + 1 == argc) {
fprintf (log_get_logfd(),
_("%s: option '%s' requires an argument\n"),
log_get_progname(), argv[i]);
exit (E_BAD_ARG);
} else {
newroot = argv[++ i];
}
}
}
if (NULL != newroot) {
change_root (newroot);
}
}
static void change_root (const char* newroot)
{
/* Drop privileges */
if ( (setregid (getgid (), getgid ()) != 0)
|| (setreuid (getuid (), getuid ()) != 0)) {
fprintf (log_get_logfd(), _("%s: failed to drop privileges (%s)\n"),
log_get_progname(), strerror (errno));
exit (EXIT_FAILURE);
}
if ('/' != newroot[0]) {
fprintf (log_get_logfd(),
_("%s: invalid chroot path '%s', only absolute paths are supported.\n"),
log_get_progname(), newroot);
exit (E_BAD_ARG);
}
if (access (newroot, F_OK) != 0) {
fprintf(log_get_logfd(),
_("%s: cannot access chroot directory %s: %s\n"),
log_get_progname(), newroot, strerror (errno));
exit (E_BAD_ARG);
}
if (chroot (newroot) != 0) {
fprintf(log_get_logfd(),
_("%s: unable to chroot to directory %s: %s\n"),
log_get_progname(), newroot, strerror (errno));
exit (E_BAD_ARG);
}
if (chdir ("/") != 0) {
fprintf(log_get_logfd(),
_("%s: cannot chdir in chroot directory %s: %s\n"),
log_get_progname(), newroot, strerror (errno));
exit (E_BAD_ARG);
}
}
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