| /* 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"); |
| } |