| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini sulogin implementation for busybox |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
| */ |
| |
| #include <syslog.h> |
| |
| #include "busybox.h" |
| |
| static const char * const forbid[] = { |
| "ENV", |
| "BASH_ENV", |
| "HOME", |
| "IFS", |
| "PATH", |
| "SHELL", |
| "LD_LIBRARY_PATH", |
| "LD_PRELOAD", |
| "LD_TRACE_LOADED_OBJECTS", |
| "LD_BIND_NOW", |
| "LD_AOUT_LIBRARY_PATH", |
| "LD_AOUT_PRELOAD", |
| "LD_NOWARN", |
| "LD_KEEPDIR", |
| (char *) 0 |
| }; |
| |
| |
| static void catchalarm(int ATTRIBUTE_UNUSED junk) |
| { |
| exit(EXIT_FAILURE); |
| } |
| |
| |
| int sulogin_main(int argc, char **argv); |
| int sulogin_main(int argc, char **argv) |
| { |
| char *cp; |
| int timeout = 0; |
| char *timeout_arg; |
| const char * const *p; |
| struct passwd *pwd; |
| const char *shell; |
| #if ENABLE_FEATURE_SHADOWPASSWDS |
| /* Using _r function to avoid pulling in static buffers */ |
| char buffer[256]; |
| struct spwd spw; |
| struct spwd *result; |
| #endif |
| |
| logmode = LOGMODE_BOTH; |
| openlog(applet_name, 0, LOG_AUTH); |
| |
| if (getopt32(argc, argv, "t:", &timeout_arg)) { |
| timeout = xatoi_u(timeout_arg); |
| } |
| |
| if (argv[optind]) { |
| close(0); |
| close(1); |
| dup(xopen(argv[optind], O_RDWR)); |
| close(2); |
| dup(0); |
| } |
| |
| if (!isatty(0) || !isatty(1) || !isatty(2)) { |
| logmode = LOGMODE_SYSLOG; |
| bb_error_msg_and_die("not a tty"); |
| } |
| |
| /* Clear out anything dangerous from the environment */ |
| for (p = forbid; *p; p++) |
| unsetenv(*p); |
| |
| signal(SIGALRM, catchalarm); |
| |
| pwd = getpwuid(0); |
| if (!pwd) { |
| goto auth_error; |
| } |
| |
| #if ENABLE_FEATURE_SHADOWPASSWDS |
| if (getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result)) { |
| goto auth_error; |
| } |
| pwd->pw_passwd = spw.sp_pwdp; |
| #endif |
| |
| while (1) { |
| /* cp points to a static buffer that is zeroed every time */ |
| cp = bb_askpass(timeout, |
| "Give root password for system maintenance\n" |
| "(or type Control-D for normal startup):"); |
| |
| if (!cp || !*cp) { |
| bb_info_msg("Normal startup"); |
| return 0; |
| } |
| if (strcmp(pw_encrypt(cp, pwd->pw_passwd), pwd->pw_passwd) == 0) { |
| break; |
| } |
| bb_do_delay(FAIL_DELAY); |
| bb_error_msg("login incorrect"); |
| } |
| memset(cp, 0, strlen(cp)); |
| signal(SIGALRM, SIG_DFL); |
| |
| bb_info_msg("System Maintenance Mode"); |
| |
| USE_SELINUX(renew_current_security_context()); |
| |
| shell = getenv("SUSHELL"); |
| if (!shell) shell = getenv("sushell"); |
| if (!shell) { |
| shell = "/bin/sh"; |
| if (pwd->pw_shell[0]) |
| shell = pwd->pw_shell; |
| } |
| run_shell(shell, 1, 0, 0); |
| /* never returns */ |
| |
| auth_error: |
| bb_error_msg_and_die("no password entry for 'root'"); |
| } |