Example #1
0
#if ENABLE_PAM
	int pamret;
	pam_handle_t *pamh;
	const char *pamuser;
	const char *failed_msg;
	struct passwd pwdstruct;
	char pwdbuf[256];
#endif

	username[0] = '\0';
	signal(SIGALRM, alarm_handler);
	alarm(TIMEOUT);

	/* More of suid paranoia if called by non-root: */
	/* Clear dangerous stuff, set PATH */
	run_by_root = !sanitize_env_if_suid();

	/* Mandatory paranoia for suid applet:
	 * ensure that fd# 0,1,2 are opened (at least to /dev/null)
	 * and any extra open fd's are closed.
	 * (The name of the function is misleading. Not daemonizing here.) */
	bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE | DAEMON_CLOSE_EXTRA_FDS, NULL);

	opt = getopt32(argv, "f:h:p", &opt_user, &opt_host);
	if (opt & LOGIN_OPT_f) {
		if (!run_by_root)
			bb_error_msg_and_die("-f is for root only");
		safe_strncpy(username, opt_user, sizeof(username));
	}
	argv += optind;
	if (argv[0]) /* user from command line (getty) */
Example #2
0
int crontab_main(int argc UNUSED_PARAM, char **argv)
{
	const struct passwd *pas;
	const char *crontab_dir = CRONTABS;
	char *tmp_fname;
	char *new_fname;
	char *user_name;  /* -u USER */
	int fd;
	int src_fd;
	int opt_ler;

	/* file [opts]     Replace crontab from file
	 * - [opts]        Replace crontab from stdin
	 * -u user         User
	 * -c dir          Crontab directory
	 * -l              List crontab for user
	 * -e              Edit crontab for user
	 * -r              Delete crontab for user
	 * bbox also supports -d == -r, but most other crontab
	 * implementations do not. Deprecated.
	 */
	enum {
		OPT_u = (1 << 0),
		OPT_c = (1 << 1),
		OPT_l = (1 << 2),
		OPT_e = (1 << 3),
		OPT_r = (1 << 4),
		OPT_ler = OPT_l + OPT_e + OPT_r,
	};

	opt_complementary = "?1:dr"; /* max one argument; -d implies -r */
	opt_ler = getopt32(argv, "u:c:lerd", &user_name, &crontab_dir);
	argv += optind;

	if (sanitize_env_if_suid()) { /* Clears dangerous stuff, sets PATH */
		/* run by non-root? */
		if (opt_ler & (OPT_u|OPT_c))
			bb_error_msg_and_die("only root can use -c or -u");
	}

	if (opt_ler & OPT_u) {
		pas = getpwnam(user_name);
		if (!pas)
			bb_error_msg_and_die("user %s is not known", user_name);
	} else {
/* XXX: xgetpwuid */
		uid_t my_uid = getuid();
		pas = getpwuid(my_uid);
		if (!pas)
			bb_perror_msg_and_die("unknown uid %d", (int)my_uid);
	}

#define user_name DONT_USE_ME_BEYOND_THIS_POINT

	/* From now on, keep only -l, -e, -r bits */
	opt_ler &= OPT_ler;
	if ((opt_ler - 1) & opt_ler) /* more than one bit set? */
		bb_show_usage();

	/* Read replacement file under user's UID/GID/group vector */
	src_fd = STDIN_FILENO;
	if (!opt_ler) { /* Replace? */
		if (!argv[0])
			bb_show_usage();
		if (NOT_LONE_DASH(argv[0])) {
			src_fd = open_as_user(pas, argv[0]);
			if (src_fd < 0)
				bb_error_msg_and_die("user %s cannot read %s",
						pas->pw_name, argv[0]);
		}
	}

	/* cd to our crontab directory */
	xchdir(crontab_dir);

	tmp_fname = NULL;

	/* Handle requested operation */
	switch (opt_ler) {

	default: /* case OPT_r: Delete */
		unlink(pas->pw_name);
		break;

	case OPT_l: /* List */
		{
			char *args[2] = { pas->pw_name, NULL };
			return bb_cat(args);
			/* list exits,
			 * the rest go play with cron update file */
		}

	case OPT_e: /* Edit */
		tmp_fname = xasprintf("%s.%u", crontab_dir, (unsigned)getpid());
		/* No O_EXCL: we don't want to be stuck if earlier crontabs
		 * were killed, leaving stale temp file behind */
		src_fd = xopen3(tmp_fname, O_RDWR|O_CREAT|O_TRUNC, 0600);
		fchown(src_fd, pas->pw_uid, pas->pw_gid);
		fd = open(pas->pw_name, O_RDONLY);
		if (fd >= 0) {
			bb_copyfd_eof(fd, src_fd);
			close(fd);
			xlseek(src_fd, 0, SEEK_SET);
		}
		close_on_exec_on(src_fd); /* don't want editor to see this fd */
		edit_file(pas, tmp_fname);
		/* fall through */

	case 0: /* Replace (no -l, -e, or -r were given) */
		new_fname = xasprintf("%s.new", pas->pw_name);
		fd = open(new_fname, O_WRONLY|O_CREAT|O_TRUNC|O_APPEND, 0600);
		if (fd >= 0) {
			bb_copyfd_eof(src_fd, fd);
			close(fd);
			xrename(new_fname, pas->pw_name);
		} else {
			bb_error_msg("cannot create %s/%s",
					crontab_dir, new_fname);
		}
		if (tmp_fname)
			unlink(tmp_fname);
		/*free(tmp_fname);*/
		/*free(new_fname);*/

	} /* switch */

	/* Bump notification file.  Handle window where crond picks file up
	 * before we can write our entry out.
	 */
	while ((fd = open(CRONUPDATE, O_WRONLY|O_CREAT|O_APPEND, 0600)) >= 0) {
		struct stat st;

		fdprintf(fd, "%s\n", pas->pw_name);
		if (fstat(fd, &st) != 0 || st.st_nlink != 0) {
			/*close(fd);*/
			break;
		}
		/* st.st_nlink == 0:
		 * file was deleted, maybe crond missed our notification */
		close(fd);
		/* loop */
	}
	if (fd < 0) {
		bb_error_msg("cannot append to %s/%s",
				crontab_dir, CRONUPDATE);
	}
	return 0;
}
Example #3
0
int sulogin_main(int argc UNUSED_PARAM, char **argv)
{
	char *cp;
	int timeout = 0;
	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;
#endif

	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;
	}

#if ENABLE_FEATURE_SHADOWPASSWDS
	{
		/* getspnam_r may return 0 yet set result to NULL.
		 * At least glibc 2.4 does this. Be extra paranoid here. */
		struct spwd *result = NULL;
		int r = getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result);
		if (r || !result) {
			goto auth_error;
		}
		pwd->pw_passwd = result->sp_pwdp;
	}
#endif

	while (1) {
		char *encrypted;
		int r;

		/* cp points to a static buffer */
		cp = bb_ask(STDIN_FILENO, timeout,
				"Give root password for system maintenance\n"
				"(or type Control-D for normal startup):");
		if (!cp) {
			/* ^D, ^C, timeout, or read error */
			bb_info_msg("Normal startup");
			return 0;
		}
		encrypted = pw_encrypt(cp, pwd->pw_passwd, 1);
		r = strcmp(encrypted, pwd->pw_passwd);
		free(encrypted);
		if (r == 0) {
			break;
		}
		bb_do_delay(LOGIN_FAIL_DELAY);
		bb_info_msg("Login incorrect");
	}
	memset(cp, 0, strlen(cp));
//	signal(SIGALRM, SIG_DFL);

	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");
}