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/* vi: set sw=4 ts=4: */
/*
* Mini sulogin implementation for busybox
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//usage:#define sulogin_trivial_usage
//usage: "[-t N] [TTY]"
//usage:#define sulogin_full_usage "\n\n"
//usage: "Single user login\n"
//usage: "\n -t N Timeout"
#include "libbb.h"
#include <syslog.h>
int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int sulogin_main(int argc UNUSED_PARAM, char **argv)
{
int timeout = 0;
struct passwd *pwd;
const char *shell;
logmode = LOGMODE_BOTH;
openlog(applet_name, 0, LOG_AUTH);
opt_complementary = "t+"; /* -t N */
getopt32(argv, "t:", &timeout);
argv += optind;
if (argv[0]) {
close(0);
close(1);
dup(xopen(argv[0], O_RDWR));
close(2);
dup(0);
}
/* Malicious use like "sulogin /dev/sda"? */
if (!isatty(0) || !isatty(1) || !isatty(2)) {
logmode = LOGMODE_SYSLOG;
bb_error_msg_and_die("not a tty");
}
/* Clear dangerous stuff, set PATH */
sanitize_env_if_suid();
pwd = getpwuid(0);
if (!pwd) {
goto auth_error;
}
while (1) {
int r;
r = ask_and_check_password_extended(pwd, timeout,
"Give root password for system maintenance\n"
"(or type Control-D for normal startup):"
);
if (r < 0) {
/* ^D, ^C, timeout, or read error */
bb_info_msg("Normal startup");
return 0;
}
if (r > 0) {
break;
}
bb_do_delay(LOGIN_FAIL_DELAY);
bb_info_msg("Login incorrect");
}
bb_info_msg("System Maintenance Mode");
IF_SELINUX(renew_current_security_context());
shell = getenv("SUSHELL");
if (!shell)
shell = getenv("sushell");
if (!shell)
shell = pwd->pw_shell;
/* Exec login shell with no additional parameters. Never returns. */
run_shell(shell, 1, NULL, NULL);
auth_error:
bb_error_msg_and_die("no password entry for root");
}
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