hush/loginutils/sulogin.c
Denis Vlasenko e5387a0574 bb_askpass: handle Ctrl-C, restore termoios on Ctrl-C.
sulogin: remove alarm handling, as it is redundant there.
code shrink. After all differences cancel out:

   text    data     bss     dec     hex filename
 777543    1000    9532  788075   c066b busybox_old
 777543    1000    9532  788075   c066b busybox_unstripped
2007-10-20 19:20:22 +00:00

129 lines
2.6 KiB
C

/* 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 "libbb.h"
static const char forbid[] ALIGN1 =
"ENV" "\0"
"BASH_ENV" "\0"
"HOME" "\0"
"IFS" "\0"
"PATH" "\0"
"SHELL" "\0"
"LD_LIBRARY_PATH" "\0"
"LD_PRELOAD" "\0"
"LD_TRACE_LOADED_OBJECTS" "\0"
"LD_BIND_NOW" "\0"
"LD_AOUT_LIBRARY_PATH" "\0"
"LD_AOUT_PRELOAD" "\0"
"LD_NOWARN" "\0"
"LD_KEEPDIR" "\0";
//static void catchalarm(int ATTRIBUTE_UNUSED junk)
//{
// exit(EXIT_FAILURE);
//}
int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int sulogin_main(int argc, char **argv)
{
char *cp;
int timeout = 0;
char *timeout_arg;
const char *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(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 */
p = forbid;
do {
unsetenv(p);
p += strlen(p) + 1;
} while (*p);
// bb_askpass() already handles this
// 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;
}
/* 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");
}