xref: /freebsd/sbin/init/init.c (revision bfe691b2f75de2224c7ceb304ebcdef2b42d4179)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Donn Seeley at Berkeley Software Design, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1991, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)init.c	8.1 (Berkeley) 7/15/93";
42 #endif
43 static const char rcsid[] =
44   "$FreeBSD$";
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/ioctl.h>
49 #include <sys/mount.h>
50 #include <sys/sysctl.h>
51 #include <sys/wait.h>
52 #include <sys/stat.h>
53 #include <sys/uio.h>
54 
55 #include <db.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <kenv.h>
59 #include <libutil.h>
60 #include <paths.h>
61 #include <signal.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include <syslog.h>
66 #include <time.h>
67 #include <ttyent.h>
68 #include <unistd.h>
69 #include <sys/reboot.h>
70 #include <err.h>
71 
72 #include <stdarg.h>
73 
74 #ifdef SECURE
75 #include <pwd.h>
76 #endif
77 
78 #ifdef LOGIN_CAP
79 #include <login_cap.h>
80 #endif
81 
82 #include "pathnames.h"
83 
84 /*
85  * Sleep times; used to prevent thrashing.
86  */
87 #define	GETTY_SPACING		 5	/* N secs minimum getty spacing */
88 #define	GETTY_SLEEP		30	/* sleep N secs after spacing problem */
89 #define GETTY_NSPACE             3      /* max. spacing count to bring reaction */
90 #define	WINDOW_WAIT		 3	/* wait N secs after starting window */
91 #define	STALL_TIMEOUT		30	/* wait N secs after warning */
92 #define	DEATH_WATCH		10	/* wait N secs for procs to die */
93 #define DEATH_SCRIPT		120	/* wait for 2min for /etc/rc.shutdown */
94 #define RESOURCE_RC		"daemon"
95 #define RESOURCE_WINDOW 	"default"
96 #define RESOURCE_GETTY		"default"
97 
98 void handle(sig_t, ...);
99 void delset(sigset_t *, ...);
100 
101 void stall(const char *, ...) __printflike(1, 2);
102 void warning(const char *, ...) __printflike(1, 2);
103 void emergency(const char *, ...) __printflike(1, 2);
104 void disaster(int);
105 void badsys(int);
106 int  runshutdown(void);
107 static char *strk(char *);
108 
109 /*
110  * We really need a recursive typedef...
111  * The following at least guarantees that the return type of (*state_t)()
112  * is sufficiently wide to hold a function pointer.
113  */
114 typedef long (*state_func_t)(void);
115 typedef state_func_t (*state_t)(void);
116 
117 state_func_t single_user(void);
118 state_func_t runcom(void);
119 state_func_t read_ttys(void);
120 state_func_t multi_user(void);
121 state_func_t clean_ttys(void);
122 state_func_t catatonia(void);
123 state_func_t death(void);
124 
125 state_func_t run_script(const char *);
126 
127 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
128 #define FALSE	0
129 #define TRUE	1
130 
131 int Reboot = FALSE;
132 int howto = RB_AUTOBOOT;
133 
134 int devfs;
135 
136 void transition(state_t);
137 state_t requested_transition;
138 
139 void setctty(const char *);
140 const char *get_shell(void);
141 void write_stderr(const char *message);
142 
143 typedef struct init_session {
144 	int	se_index;		/* index of entry in ttys file */
145 	pid_t	se_process;		/* controlling process */
146 	time_t	se_started;		/* used to avoid thrashing */
147 	int	se_flags;		/* status of session */
148 #define	SE_SHUTDOWN	0x1		/* session won't be restarted */
149 #define	SE_PRESENT	0x2		/* session is in /etc/ttys */
150 	int     se_nspace;              /* spacing count */
151 	char	*se_device;		/* filename of port */
152 	char	*se_getty;		/* what to run on that port */
153 	char    *se_getty_argv_space;   /* pre-parsed argument array space */
154 	char	**se_getty_argv;	/* pre-parsed argument array */
155 	char	*se_window;		/* window system (started only once) */
156 	char    *se_window_argv_space;  /* pre-parsed argument array space */
157 	char	**se_window_argv;	/* pre-parsed argument array */
158 	char    *se_type;               /* default terminal type */
159 	struct	init_session *se_prev;
160 	struct	init_session *se_next;
161 } session_t;
162 
163 void free_session(session_t *);
164 session_t *new_session(session_t *, int, struct ttyent *);
165 session_t *sessions;
166 
167 char **construct_argv(char *);
168 void start_window_system(session_t *);
169 void collect_child(pid_t);
170 pid_t start_getty(session_t *);
171 void transition_handler(int);
172 void alrm_handler(int);
173 void setsecuritylevel(int);
174 int getsecuritylevel(void);
175 int setupargv(session_t *, struct ttyent *);
176 #ifdef LOGIN_CAP
177 void setprocresources(const char *);
178 #endif
179 int clang;
180 
181 void clear_session_logs(session_t *);
182 
183 int start_session_db(void);
184 void add_session(session_t *);
185 void del_session(session_t *);
186 session_t *find_session(pid_t);
187 DB *session_db;
188 
189 /*
190  * The mother of all processes.
191  */
192 int
193 main(int argc, char *argv[])
194 {
195 	state_t initial_transition = runcom;
196 	char kenv_value[PATH_MAX];
197 	int c;
198 	struct sigaction sa;
199 	sigset_t mask;
200 
201 
202 	/* Dispose of random users. */
203 	if (getuid() != 0)
204 		errx(1, "%s", strerror(EPERM));
205 
206 	/* System V users like to reexec init. */
207 	if (getpid() != 1) {
208 #ifdef COMPAT_SYSV_INIT
209 		/* So give them what they want */
210 		if (argc > 1) {
211 			if (strlen(argv[1]) == 1) {
212 				char runlevel = *argv[1];
213 				int sig;
214 
215 				switch (runlevel) {
216 					case '0': /* halt + poweroff */
217 						sig = SIGUSR2;
218 						break;
219 					case '1': /* single-user */
220 						sig = SIGTERM;
221 						break;
222 					case '6': /* reboot */
223 						sig = SIGINT;
224 						break;
225 					case 'c': /* block further logins */
226 						sig = SIGTSTP;
227 						break;
228 					case 'q': /* rescan /etc/ttys */
229 						sig = SIGHUP;
230 						break;
231 					default:
232 						goto invalid;
233 				}
234 				kill(1, sig);
235 				_exit(0);
236 			} else
237 invalid:
238 				errx(1, "invalid run-level ``%s''", argv[1]);
239 		} else
240 #endif
241 			errx(1, "already running");
242 	}
243 	/*
244 	 * Note that this does NOT open a file...
245 	 * Does 'init' deserve its own facility number?
246 	 */
247 	openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
248 
249 	/*
250 	 * Create an initial session.
251 	 */
252 	if (setsid() < 0)
253 		warning("initial setsid() failed: %m");
254 
255 	/*
256 	 * Establish an initial user so that programs running
257 	 * single user do not freak out and die (like passwd).
258 	 */
259 	if (setlogin("root") < 0)
260 		warning("setlogin() failed: %m");
261 
262 	/*
263 	 * This code assumes that we always get arguments through flags,
264 	 * never through bits set in some random machine register.
265 	 */
266 	while ((c = getopt(argc, argv, "dsf")) != -1)
267 		switch (c) {
268 		case 'd':
269 			devfs = 1;
270 			break;
271 		case 's':
272 			initial_transition = single_user;
273 			break;
274 		case 'f':
275 			runcom_mode = FASTBOOT;
276 			break;
277 		default:
278 			warning("unrecognized flag '-%c'", c);
279 			break;
280 		}
281 
282 	if (optind != argc)
283 		warning("ignoring excess arguments");
284 
285 	/*
286 	 * We catch or block signals rather than ignore them,
287 	 * so that they get reset on exec.
288 	 */
289 	handle(badsys, SIGSYS, 0);
290 	handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
291 	       SIGBUS, SIGXCPU, SIGXFSZ, 0);
292 	handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP,
293 		SIGUSR1, SIGUSR2, 0);
294 	handle(alrm_handler, SIGALRM, 0);
295 	sigfillset(&mask);
296 	delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
297 		SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
298 		SIGUSR1, SIGUSR2, 0);
299 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
300 	sigemptyset(&sa.sa_mask);
301 	sa.sa_flags = 0;
302 	sa.sa_handler = SIG_IGN;
303 	(void) sigaction(SIGTTIN, &sa, (struct sigaction *)0);
304 	(void) sigaction(SIGTTOU, &sa, (struct sigaction *)0);
305 
306 	/*
307 	 * Paranoia.
308 	 */
309 	close(0);
310 	close(1);
311 	close(2);
312 
313 	if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
314 		state_func_t next_transition;
315 
316 		if ((next_transition = run_script(kenv_value)) != 0)
317 			initial_transition = (state_t) next_transition;
318 	}
319 
320 	if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
321 		if (chdir(kenv_value) != 0 || chroot(".") != 0)
322 			warning("Can't chroot to %s: %m", kenv_value);
323 	}
324 
325 	/*
326 	 * Additional check if devfs needs to be mounted:
327 	 * If "/" and "/dev" have the same device number,
328 	 * then it hasn't been mounted yet.
329 	 */
330 	if (!devfs) {
331 		struct stat stst;
332 		dev_t root_devno;
333 
334 		stat("/", &stst);
335 		root_devno = stst.st_dev;
336 		if (stat("/dev", &stst) != 0)
337 			warning("Can't stat /dev: %m");
338 		else if (stst.st_dev == root_devno)
339 			devfs++;
340 	}
341 
342 	if (devfs) {
343 		struct iovec iov[4];
344 		char *s;
345 		int i;
346 
347 		char _fstype[]	= "fstype";
348 		char _devfs[]	= "devfs";
349 		char _fspath[]	= "fspath";
350 		char _path_dev[]= _PATH_DEV;
351 
352 		iov[0].iov_base = _fstype;
353 		iov[0].iov_len = sizeof(_fstype);
354 		iov[1].iov_base = _devfs;
355 		iov[1].iov_len = sizeof(_devfs);
356 		iov[2].iov_base = _fspath;
357 		iov[2].iov_len = sizeof(_fspath);
358 		/*
359 		 * Try to avoid the trailing slash in _PATH_DEV.
360 		 * Be *very* defensive.
361 		 */
362 		s = strdup(_PATH_DEV);
363 		if (s != NULL) {
364 			i = strlen(s);
365 			if (i > 0 && s[i - 1] == '/')
366 				s[i - 1] = '\0';
367 			iov[3].iov_base = s;
368 			iov[3].iov_len = strlen(s) + 1;
369 		} else {
370 			iov[3].iov_base = _path_dev;
371 			iov[3].iov_len = sizeof(_path_dev);
372 		}
373 		nmount(iov, 4, 0);
374 		if (s != NULL)
375 			free(s);
376 	}
377 
378 	/*
379 	 * Start the state machine.
380 	 */
381 	transition(initial_transition);
382 
383 	/*
384 	 * Should never reach here.
385 	 */
386 	return 1;
387 }
388 
389 /*
390  * Associate a function with a signal handler.
391  */
392 void
393 handle(sig_t handler, ...)
394 {
395 	int sig;
396 	struct sigaction sa;
397 	sigset_t mask_everything;
398 	va_list ap;
399 	va_start(ap, handler);
400 
401 	sa.sa_handler = handler;
402 	sigfillset(&mask_everything);
403 
404 	while ((sig = va_arg(ap, int)) != 0) {
405 		sa.sa_mask = mask_everything;
406 		/* XXX SA_RESTART? */
407 		sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
408 		sigaction(sig, &sa, (struct sigaction *) 0);
409 	}
410 	va_end(ap);
411 }
412 
413 /*
414  * Delete a set of signals from a mask.
415  */
416 void
417 delset(sigset_t *maskp, ...)
418 {
419 	int sig;
420 	va_list ap;
421 	va_start(ap, maskp);
422 
423 	while ((sig = va_arg(ap, int)) != 0)
424 		sigdelset(maskp, sig);
425 	va_end(ap);
426 }
427 
428 /*
429  * Log a message and sleep for a while (to give someone an opportunity
430  * to read it and to save log or hardcopy output if the problem is chronic).
431  * NB: should send a message to the session logger to avoid blocking.
432  */
433 void
434 stall(const char *message, ...)
435 {
436 	va_list ap;
437 	va_start(ap, message);
438 
439 	vsyslog(LOG_ALERT, message, ap);
440 	va_end(ap);
441 	sleep(STALL_TIMEOUT);
442 }
443 
444 /*
445  * Like stall(), but doesn't sleep.
446  * If cpp had variadic macros, the two functions could be #defines for another.
447  * NB: should send a message to the session logger to avoid blocking.
448  */
449 void
450 warning(const char *message, ...)
451 {
452 	va_list ap;
453 	va_start(ap, message);
454 
455 	vsyslog(LOG_ALERT, message, ap);
456 	va_end(ap);
457 }
458 
459 /*
460  * Log an emergency message.
461  * NB: should send a message to the session logger to avoid blocking.
462  */
463 void
464 emergency(const char *message, ...)
465 {
466 	va_list ap;
467 	va_start(ap, message);
468 
469 	vsyslog(LOG_EMERG, message, ap);
470 	va_end(ap);
471 }
472 
473 /*
474  * Catch a SIGSYS signal.
475  *
476  * These may arise if a system does not support sysctl.
477  * We tolerate up to 25 of these, then throw in the towel.
478  */
479 void
480 badsys(int sig)
481 {
482 	static int badcount = 0;
483 
484 	if (badcount++ < 25)
485 		return;
486 	disaster(sig);
487 }
488 
489 /*
490  * Catch an unexpected signal.
491  */
492 void
493 disaster(int sig)
494 {
495 	emergency("fatal signal: %s",
496 		(unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
497 
498 	sleep(STALL_TIMEOUT);
499 	_exit(sig);		/* reboot */
500 }
501 
502 /*
503  * Get the security level of the kernel.
504  */
505 int
506 getsecuritylevel(void)
507 {
508 #ifdef KERN_SECURELVL
509 	int name[2], curlevel;
510 	size_t len;
511 
512 	name[0] = CTL_KERN;
513 	name[1] = KERN_SECURELVL;
514 	len = sizeof curlevel;
515 	if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
516 		emergency("cannot get kernel security level: %s",
517 		    strerror(errno));
518 		return (-1);
519 	}
520 	return (curlevel);
521 #else
522 	return (-1);
523 #endif
524 }
525 
526 /*
527  * Set the security level of the kernel.
528  */
529 void
530 setsecuritylevel(int newlevel)
531 {
532 #ifdef KERN_SECURELVL
533 	int name[2], curlevel;
534 
535 	curlevel = getsecuritylevel();
536 	if (newlevel == curlevel)
537 		return;
538 	name[0] = CTL_KERN;
539 	name[1] = KERN_SECURELVL;
540 	if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
541 		emergency(
542 		    "cannot change kernel security level from %d to %d: %s",
543 		    curlevel, newlevel, strerror(errno));
544 		return;
545 	}
546 #ifdef SECURE
547 	warning("kernel security level changed from %d to %d",
548 	    curlevel, newlevel);
549 #endif
550 #endif
551 }
552 
553 /*
554  * Change states in the finite state machine.
555  * The initial state is passed as an argument.
556  */
557 void
558 transition(state_t s)
559 {
560 	for (;;)
561 		s = (state_t) (*s)();
562 }
563 
564 /*
565  * Close out the accounting files for a login session.
566  * NB: should send a message to the session logger to avoid blocking.
567  */
568 void
569 clear_session_logs(session_t *sp)
570 {
571 	char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
572 
573 	if (logout(line))
574 		logwtmp(line, "", "");
575 }
576 
577 /*
578  * Start a session and allocate a controlling terminal.
579  * Only called by children of init after forking.
580  */
581 void
582 setctty(const char *name)
583 {
584 	int fd;
585 
586 	(void) revoke(name);
587 	if ((fd = open(name, O_RDWR)) == -1) {
588 		stall("can't open %s: %m", name);
589 		_exit(1);
590 	}
591 	if (login_tty(fd) == -1) {
592 		stall("can't get %s for controlling terminal: %m", name);
593 		_exit(1);
594 	}
595 }
596 
597 const char *
598 get_shell(void)
599 {
600 	static char kenv_value[PATH_MAX];
601 
602 	if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
603 		return kenv_value;
604 	else
605 		return _PATH_BSHELL;
606 }
607 
608 void
609 write_stderr(const char *message)
610 {
611 	write(STDERR_FILENO, message, strlen(message));
612 }
613 
614 /*
615  * Bring the system up single user.
616  */
617 state_func_t
618 single_user(void)
619 {
620 	pid_t pid, wpid;
621 	int status;
622 	sigset_t mask;
623 	const char *shell;
624 	char *argv[2];
625 #ifdef SECURE
626 	struct ttyent *typ;
627 	struct passwd *pp;
628 	static const char banner[] =
629 		"Enter root password, or ^D to go multi-user\n";
630 	char *clear, *password;
631 #endif
632 #ifdef DEBUGSHELL
633 	char altshell[128];
634 #endif
635 
636 	if (Reboot) {
637 		/* Instead of going single user, let's reboot the machine */
638 		sync();
639 		alarm(2);
640 		pause();
641 		reboot(howto);
642 		_exit(0);
643 	}
644 
645 	shell = get_shell();
646 
647 	if ((pid = fork()) == 0) {
648 		/*
649 		 * Start the single user session.
650 		 */
651 		setctty(_PATH_CONSOLE);
652 
653 #ifdef SECURE
654 		/*
655 		 * Check the root password.
656 		 * We don't care if the console is 'on' by default;
657 		 * it's the only tty that can be 'off' and 'secure'.
658 		 */
659 		typ = getttynam("console");
660 		pp = getpwnam("root");
661 		if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
662 		    pp && *pp->pw_passwd) {
663 			write_stderr(banner);
664 			for (;;) {
665 				clear = getpass("Password:");
666 				if (clear == 0 || *clear == '\0')
667 					_exit(0);
668 				password = crypt(clear, pp->pw_passwd);
669 				bzero(clear, _PASSWORD_LEN);
670 				if (strcmp(password, pp->pw_passwd) == 0)
671 					break;
672 				warning("single-user login failed\n");
673 			}
674 		}
675 		endttyent();
676 		endpwent();
677 #endif /* SECURE */
678 
679 #ifdef DEBUGSHELL
680 		{
681 			char *cp = altshell;
682 			int num;
683 
684 #define	SHREQUEST "Enter full pathname of shell or RETURN for "
685 			write_stderr(SHREQUEST);
686 			write_stderr(shell);
687 			write_stderr(": ");
688 			while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
689 			    num != 0 && *cp != '\n' && cp < &altshell[127])
690 					cp++;
691 			*cp = '\0';
692 			if (altshell[0] != '\0')
693 				shell = altshell;
694 		}
695 #endif /* DEBUGSHELL */
696 
697 		/*
698 		 * Unblock signals.
699 		 * We catch all the interesting ones,
700 		 * and those are reset to SIG_DFL on exec.
701 		 */
702 		sigemptyset(&mask);
703 		sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
704 
705 		/*
706 		 * Fire off a shell.
707 		 * If the default one doesn't work, try the Bourne shell.
708 		 */
709 
710 		char name[] = "-sh";
711 
712 		argv[0] = name;
713 		argv[1] = 0;
714 		execv(shell, argv);
715 		emergency("can't exec %s for single user: %m", shell);
716 		execv(_PATH_BSHELL, argv);
717 		emergency("can't exec %s for single user: %m", _PATH_BSHELL);
718 		sleep(STALL_TIMEOUT);
719 		_exit(1);
720 	}
721 
722 	if (pid == -1) {
723 		/*
724 		 * We are seriously hosed.  Do our best.
725 		 */
726 		emergency("can't fork single-user shell, trying again");
727 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
728 			continue;
729 		return (state_func_t) single_user;
730 	}
731 
732 	requested_transition = 0;
733 	do {
734 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
735 			collect_child(wpid);
736 		if (wpid == -1) {
737 			if (errno == EINTR)
738 				continue;
739 			warning("wait for single-user shell failed: %m; restarting");
740 			return (state_func_t) single_user;
741 		}
742 		if (wpid == pid && WIFSTOPPED(status)) {
743 			warning("init: shell stopped, restarting\n");
744 			kill(pid, SIGCONT);
745 			wpid = -1;
746 		}
747 	} while (wpid != pid && !requested_transition);
748 
749 	if (requested_transition)
750 		return (state_func_t) requested_transition;
751 
752 	if (!WIFEXITED(status)) {
753 		if (WTERMSIG(status) == SIGKILL) {
754 			/*
755 			 *  reboot(8) killed shell?
756 			 */
757 			warning("single user shell terminated.");
758 			sleep(STALL_TIMEOUT);
759 			_exit(0);
760 		} else {
761 			warning("single user shell terminated, restarting");
762 			return (state_func_t) single_user;
763 		}
764 	}
765 
766 	runcom_mode = FASTBOOT;
767 	return (state_func_t) runcom;
768 }
769 
770 /*
771  * Run the system startup script.
772  */
773 state_func_t
774 runcom(void)
775 {
776 	state_func_t next_transition;
777 
778 	if ((next_transition = run_script(_PATH_RUNCOM)) != 0)
779 		return next_transition;
780 
781 	runcom_mode = AUTOBOOT;		/* the default */
782 	/* NB: should send a message to the session logger to avoid blocking. */
783 	logwtmp("~", "reboot", "");
784 	return (state_func_t) read_ttys;
785 }
786 
787 /*
788  * Run a shell script.
789  * Returns 0 on success, otherwise the next transition to enter:
790  *  - single_user if fork/execv/waitpid failed, or if the script
791  *    terminated with a signal or exit code != 0.
792  *  - death if a SIGTERM was delivered to init(8).
793  */
794 state_func_t
795 run_script(const char *script)
796 {
797 	pid_t pid, wpid;
798 	int status;
799 	char *argv[4];
800 	const char *shell;
801 	struct sigaction sa;
802 
803 	shell = get_shell();
804 
805 	if ((pid = fork()) == 0) {
806 		sigemptyset(&sa.sa_mask);
807 		sa.sa_flags = 0;
808 		sa.sa_handler = SIG_IGN;
809 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
810 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
811 
812 		setctty(_PATH_CONSOLE);
813 
814 		char _sh[]	 	= "sh";
815 		char _autoboot[]	= "autoboot";
816 
817 		argv[0] = _sh;
818 		argv[1] = __DECONST(char *, script);
819 		argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0;
820 		argv[3] = 0;
821 
822 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
823 
824 #ifdef LOGIN_CAP
825 		setprocresources(RESOURCE_RC);
826 #endif
827 		execv(shell, argv);
828 		stall("can't exec %s for %s: %m", shell, script);
829 		_exit(1);	/* force single user mode */
830 	}
831 
832 	if (pid == -1) {
833 		emergency("can't fork for %s on %s: %m", shell, script);
834 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
835 			continue;
836 		sleep(STALL_TIMEOUT);
837 		return (state_func_t) single_user;
838 	}
839 
840 	/*
841 	 * Copied from single_user().  This is a bit paranoid.
842 	 */
843 	requested_transition = 0;
844 	do {
845 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
846 			collect_child(wpid);
847 		if (wpid == -1) {
848 			if (requested_transition == death)
849 				return (state_func_t) death;
850 			if (errno == EINTR)
851 				continue;
852 			warning("wait for %s on %s failed: %m; going to "
853 			    "single user mode", shell, script);
854 			return (state_func_t) single_user;
855 		}
856 		if (wpid == pid && WIFSTOPPED(status)) {
857 			warning("init: %s on %s stopped, restarting\n",
858 				shell, script);
859 			kill(pid, SIGCONT);
860 			wpid = -1;
861 		}
862 	} while (wpid != pid);
863 
864 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
865 	    requested_transition == catatonia) {
866 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
867 		sigset_t s;
868 
869 		sigfillset(&s);
870 		for (;;)
871 			sigsuspend(&s);
872 	}
873 
874 	if (!WIFEXITED(status)) {
875 		warning("%s on %s terminated abnormally, going to single "
876 		    "user mode", shell, script);
877 		return (state_func_t) single_user;
878 	}
879 
880 	if (WEXITSTATUS(status))
881 		return (state_func_t) single_user;
882 
883 	return (state_func_t) 0;
884 }
885 
886 /*
887  * Open the session database.
888  *
889  * NB: We could pass in the size here; is it necessary?
890  */
891 int
892 start_session_db(void)
893 {
894 	if (session_db && (*session_db->close)(session_db))
895 		emergency("session database close: %s", strerror(errno));
896 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
897 		emergency("session database open: %s", strerror(errno));
898 		return (1);
899 	}
900 	return (0);
901 
902 }
903 
904 /*
905  * Add a new login session.
906  */
907 void
908 add_session(session_t *sp)
909 {
910 	DBT key;
911 	DBT data;
912 
913 	key.data = &sp->se_process;
914 	key.size = sizeof sp->se_process;
915 	data.data = &sp;
916 	data.size = sizeof sp;
917 
918 	if ((*session_db->put)(session_db, &key, &data, 0))
919 		emergency("insert %d: %s", sp->se_process, strerror(errno));
920 }
921 
922 /*
923  * Delete an old login session.
924  */
925 void
926 del_session(session_t *sp)
927 {
928 	DBT key;
929 
930 	key.data = &sp->se_process;
931 	key.size = sizeof sp->se_process;
932 
933 	if ((*session_db->del)(session_db, &key, 0))
934 		emergency("delete %d: %s", sp->se_process, strerror(errno));
935 }
936 
937 /*
938  * Look up a login session by pid.
939  */
940 session_t *
941 find_session(pid_t pid)
942 {
943 	DBT key;
944 	DBT data;
945 	session_t *ret;
946 
947 	key.data = &pid;
948 	key.size = sizeof pid;
949 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
950 		return 0;
951 	bcopy(data.data, (char *)&ret, sizeof(ret));
952 	return ret;
953 }
954 
955 /*
956  * Construct an argument vector from a command line.
957  */
958 char **
959 construct_argv(char *command)
960 {
961 	int argc = 0;
962 	char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
963 						* sizeof (char *));
964 
965 	if ((argv[argc++] = strk(command)) == 0) {
966 		free(argv);
967 		return (NULL);
968 	}
969 	while ((argv[argc++] = strk((char *) 0)) != NULL)
970 		continue;
971 	return argv;
972 }
973 
974 /*
975  * Deallocate a session descriptor.
976  */
977 void
978 free_session(session_t *sp)
979 {
980 	free(sp->se_device);
981 	if (sp->se_getty) {
982 		free(sp->se_getty);
983 		free(sp->se_getty_argv_space);
984 		free(sp->se_getty_argv);
985 	}
986 	if (sp->se_window) {
987 		free(sp->se_window);
988 		free(sp->se_window_argv_space);
989 		free(sp->se_window_argv);
990 	}
991 	if (sp->se_type)
992 		free(sp->se_type);
993 	free(sp);
994 }
995 
996 /*
997  * Allocate a new session descriptor.
998  * Mark it SE_PRESENT.
999  */
1000 session_t *
1001 new_session(session_t *sprev, int session_index, struct ttyent *typ)
1002 {
1003 	session_t *sp;
1004 	int fd;
1005 
1006 	if ((typ->ty_status & TTY_ON) == 0 ||
1007 	    typ->ty_name == 0 ||
1008 	    typ->ty_getty == 0)
1009 		return 0;
1010 
1011 	sp = (session_t *) calloc(1, sizeof (session_t));
1012 
1013 	sp->se_index = session_index;
1014 	sp->se_flags |= SE_PRESENT;
1015 
1016 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
1017 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
1018 
1019 	/*
1020 	 * Attempt to open the device, if we get "device not configured"
1021 	 * then don't add the device to the session list.
1022 	 */
1023 	if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
1024 		if (errno == ENXIO) {
1025 			free_session(sp);
1026 			return (0);
1027 		}
1028 	} else
1029 		close(fd);
1030 
1031 	if (setupargv(sp, typ) == 0) {
1032 		free_session(sp);
1033 		return (0);
1034 	}
1035 
1036 	sp->se_next = 0;
1037 	if (sprev == 0) {
1038 		sessions = sp;
1039 		sp->se_prev = 0;
1040 	} else {
1041 		sprev->se_next = sp;
1042 		sp->se_prev = sprev;
1043 	}
1044 
1045 	return sp;
1046 }
1047 
1048 /*
1049  * Calculate getty and if useful window argv vectors.
1050  */
1051 int
1052 setupargv(session_t *sp, struct ttyent *typ)
1053 {
1054 
1055 	if (sp->se_getty) {
1056 		free(sp->se_getty);
1057 		free(sp->se_getty_argv_space);
1058 		free(sp->se_getty_argv);
1059 	}
1060 	sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1061 	(void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1062 	sp->se_getty_argv_space = strdup(sp->se_getty);
1063 	sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1064 	if (sp->se_getty_argv == 0) {
1065 		warning("can't parse getty for port %s", sp->se_device);
1066 		free(sp->se_getty);
1067 		free(sp->se_getty_argv_space);
1068 		sp->se_getty = sp->se_getty_argv_space = 0;
1069 		return (0);
1070 	}
1071 	if (sp->se_window) {
1072 		free(sp->se_window);
1073 		free(sp->se_window_argv_space);
1074 		free(sp->se_window_argv);
1075 	}
1076 	sp->se_window = sp->se_window_argv_space = 0;
1077 	sp->se_window_argv = 0;
1078 	if (typ->ty_window) {
1079 		sp->se_window = strdup(typ->ty_window);
1080 		sp->se_window_argv_space = strdup(sp->se_window);
1081 		sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1082 		if (sp->se_window_argv == 0) {
1083 			warning("can't parse window for port %s",
1084 				sp->se_device);
1085 			free(sp->se_window_argv_space);
1086 			free(sp->se_window);
1087 			sp->se_window = sp->se_window_argv_space = 0;
1088 			return (0);
1089 		}
1090 	}
1091 	if (sp->se_type)
1092 		free(sp->se_type);
1093 	sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1094 	return (1);
1095 }
1096 
1097 /*
1098  * Walk the list of ttys and create sessions for each active line.
1099  */
1100 state_func_t
1101 read_ttys(void)
1102 {
1103 	int session_index = 0;
1104 	session_t *sp, *snext;
1105 	struct ttyent *typ;
1106 
1107 	/*
1108 	 * Destroy any previous session state.
1109 	 * There shouldn't be any, but just in case...
1110 	 */
1111 	for (sp = sessions; sp; sp = snext) {
1112 		if (sp->se_process)
1113 			clear_session_logs(sp);
1114 		snext = sp->se_next;
1115 		free_session(sp);
1116 	}
1117 	sessions = 0;
1118 	if (start_session_db())
1119 		return (state_func_t) single_user;
1120 
1121 	/*
1122 	 * Allocate a session entry for each active port.
1123 	 * Note that sp starts at 0.
1124 	 */
1125 	while ((typ = getttyent()) != NULL)
1126 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1127 			sp = snext;
1128 
1129 	endttyent();
1130 
1131 	return (state_func_t) multi_user;
1132 }
1133 
1134 /*
1135  * Start a window system running.
1136  */
1137 void
1138 start_window_system(session_t *sp)
1139 {
1140 	pid_t pid;
1141 	sigset_t mask;
1142 	char term[64], *env[2];
1143 	int status;
1144 
1145 	if ((pid = fork()) == -1) {
1146 		emergency("can't fork for window system on port %s: %m",
1147 			sp->se_device);
1148 		/* hope that getty fails and we can try again */
1149 		return;
1150 	}
1151 	if (pid)
1152 	{
1153 		waitpid(-1, &status, 0);
1154 		return;
1155 	}
1156 
1157 	/* reparent window process to the init to not make a zombie on exit */
1158 	if ((pid = fork()) == -1) {
1159 		emergency("can't fork for window system on port %s: %m",
1160 			sp->se_device);
1161 		_exit(1);
1162 	}
1163 	if (pid)
1164 		_exit(0);
1165 
1166 	sigemptyset(&mask);
1167 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1168 
1169 	if (setsid() < 0)
1170 		emergency("setsid failed (window) %m");
1171 
1172 #ifdef LOGIN_CAP
1173 	setprocresources(RESOURCE_WINDOW);
1174 #endif
1175 	if (sp->se_type) {
1176 		/* Don't use malloc after fork */
1177 		strcpy(term, "TERM=");
1178 		strncat(term, sp->se_type, sizeof(term) - 6);
1179 		env[0] = term;
1180 		env[1] = 0;
1181 	}
1182 	else
1183 		env[0] = 0;
1184 	execve(sp->se_window_argv[0], sp->se_window_argv, env);
1185 	stall("can't exec window system '%s' for port %s: %m",
1186 		sp->se_window_argv[0], sp->se_device);
1187 	_exit(1);
1188 }
1189 
1190 /*
1191  * Start a login session running.
1192  */
1193 pid_t
1194 start_getty(session_t *sp)
1195 {
1196 	pid_t pid;
1197 	sigset_t mask;
1198 	time_t current_time = time((time_t *) 0);
1199 	int too_quick = 0;
1200 	char term[64], *env[2];
1201 
1202 	if (current_time >= sp->se_started &&
1203 	    current_time - sp->se_started < GETTY_SPACING) {
1204 		if (++sp->se_nspace > GETTY_NSPACE) {
1205 			sp->se_nspace = 0;
1206 			too_quick = 1;
1207 		}
1208 	} else
1209 		sp->se_nspace = 0;
1210 
1211 	/*
1212 	 * fork(), not vfork() -- we can't afford to block.
1213 	 */
1214 	if ((pid = fork()) == -1) {
1215 		emergency("can't fork for getty on port %s: %m", sp->se_device);
1216 		return -1;
1217 	}
1218 
1219 	if (pid)
1220 		return pid;
1221 
1222 	if (too_quick) {
1223 		warning("getty repeating too quickly on port %s, sleeping %d secs",
1224 			sp->se_device, GETTY_SLEEP);
1225 		sleep((unsigned) GETTY_SLEEP);
1226 	}
1227 
1228 	if (sp->se_window) {
1229 		start_window_system(sp);
1230 		sleep(WINDOW_WAIT);
1231 	}
1232 
1233 	sigemptyset(&mask);
1234 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1235 
1236 #ifdef LOGIN_CAP
1237 	setprocresources(RESOURCE_GETTY);
1238 #endif
1239 	if (sp->se_type) {
1240 		/* Don't use malloc after fork */
1241 		strcpy(term, "TERM=");
1242 		strncat(term, sp->se_type, sizeof(term) - 6);
1243 		env[0] = term;
1244 		env[1] = 0;
1245 	}
1246 	else
1247 		env[0] = 0;
1248 	execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1249 	stall("can't exec getty '%s' for port %s: %m",
1250 		sp->se_getty_argv[0], sp->se_device);
1251 	_exit(1);
1252 }
1253 
1254 /*
1255  * Collect exit status for a child.
1256  * If an exiting login, start a new login running.
1257  */
1258 void
1259 collect_child(pid_t pid)
1260 {
1261 	session_t *sp, *sprev, *snext;
1262 
1263 	if (! sessions)
1264 		return;
1265 
1266 	if (! (sp = find_session(pid)))
1267 		return;
1268 
1269 	clear_session_logs(sp);
1270 	del_session(sp);
1271 	sp->se_process = 0;
1272 
1273 	if (sp->se_flags & SE_SHUTDOWN) {
1274 		if ((sprev = sp->se_prev) != NULL)
1275 			sprev->se_next = sp->se_next;
1276 		else
1277 			sessions = sp->se_next;
1278 		if ((snext = sp->se_next) != NULL)
1279 			snext->se_prev = sp->se_prev;
1280 		free_session(sp);
1281 		return;
1282 	}
1283 
1284 	if ((pid = start_getty(sp)) == -1) {
1285 		/* serious trouble */
1286 		requested_transition = clean_ttys;
1287 		return;
1288 	}
1289 
1290 	sp->se_process = pid;
1291 	sp->se_started = time((time_t *) 0);
1292 	add_session(sp);
1293 }
1294 
1295 /*
1296  * Catch a signal and request a state transition.
1297  */
1298 void
1299 transition_handler(int sig)
1300 {
1301 
1302 	switch (sig) {
1303 	case SIGHUP:
1304 		requested_transition = clean_ttys;
1305 		break;
1306 	case SIGUSR2:
1307 		howto = RB_POWEROFF;
1308 	case SIGUSR1:
1309 		howto |= RB_HALT;
1310 	case SIGINT:
1311 		Reboot = TRUE;
1312 	case SIGTERM:
1313 		requested_transition = death;
1314 		break;
1315 	case SIGTSTP:
1316 		requested_transition = catatonia;
1317 		break;
1318 	default:
1319 		requested_transition = 0;
1320 		break;
1321 	}
1322 }
1323 
1324 /*
1325  * Take the system multiuser.
1326  */
1327 state_func_t
1328 multi_user(void)
1329 {
1330 	pid_t pid;
1331 	session_t *sp;
1332 
1333 	requested_transition = 0;
1334 
1335 	/*
1336 	 * If the administrator has not set the security level to -1
1337 	 * to indicate that the kernel should not run multiuser in secure
1338 	 * mode, and the run script has not set a higher level of security
1339 	 * than level 1, then put the kernel into secure mode.
1340 	 */
1341 	if (getsecuritylevel() == 0)
1342 		setsecuritylevel(1);
1343 
1344 	for (sp = sessions; sp; sp = sp->se_next) {
1345 		if (sp->se_process)
1346 			continue;
1347 		if ((pid = start_getty(sp)) == -1) {
1348 			/* serious trouble */
1349 			requested_transition = clean_ttys;
1350 			break;
1351 		}
1352 		sp->se_process = pid;
1353 		sp->se_started = time((time_t *) 0);
1354 		add_session(sp);
1355 	}
1356 
1357 	while (!requested_transition)
1358 		if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1359 			collect_child(pid);
1360 
1361 	return (state_func_t) requested_transition;
1362 }
1363 
1364 /*
1365  * This is an (n*2)+(n^2) algorithm.  We hope it isn't run often...
1366  */
1367 state_func_t
1368 clean_ttys(void)
1369 {
1370 	session_t *sp, *sprev;
1371 	struct ttyent *typ;
1372 	int session_index = 0;
1373 	int devlen;
1374 	char *old_getty, *old_window, *old_type;
1375 
1376 	/*
1377 	 * mark all sessions for death, (!SE_PRESENT)
1378 	 * as we find or create new ones they'll be marked as keepers,
1379 	 * we'll later nuke all the ones not found in /etc/ttys
1380 	 */
1381 	for (sp = sessions; sp != NULL; sp = sp->se_next)
1382 		sp->se_flags &= ~SE_PRESENT;
1383 
1384 	devlen = sizeof(_PATH_DEV) - 1;
1385 	while ((typ = getttyent()) != NULL) {
1386 		++session_index;
1387 
1388 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1389 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1390 				break;
1391 
1392 		if (sp) {
1393 			/* we want this one to live */
1394 			sp->se_flags |= SE_PRESENT;
1395 			if (sp->se_index != session_index) {
1396 				warning("port %s changed utmp index from %d to %d",
1397 				       sp->se_device, sp->se_index,
1398 				       session_index);
1399 				sp->se_index = session_index;
1400 			}
1401 			if ((typ->ty_status & TTY_ON) == 0 ||
1402 			    typ->ty_getty == 0) {
1403 				sp->se_flags |= SE_SHUTDOWN;
1404 				kill(sp->se_process, SIGHUP);
1405 				continue;
1406 			}
1407 			sp->se_flags &= ~SE_SHUTDOWN;
1408 			old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1409 			old_window = sp->se_window ? strdup(sp->se_window) : 0;
1410 			old_type = sp->se_type ? strdup(sp->se_type) : 0;
1411 			if (setupargv(sp, typ) == 0) {
1412 				warning("can't parse getty for port %s",
1413 					sp->se_device);
1414 				sp->se_flags |= SE_SHUTDOWN;
1415 				kill(sp->se_process, SIGHUP);
1416 			}
1417 			else if (   !old_getty
1418 				 || (!old_type && sp->se_type)
1419 				 || (old_type && !sp->se_type)
1420 				 || (!old_window && sp->se_window)
1421 				 || (old_window && !sp->se_window)
1422 				 || (strcmp(old_getty, sp->se_getty) != 0)
1423 				 || (old_window && strcmp(old_window, sp->se_window) != 0)
1424 				 || (old_type && strcmp(old_type, sp->se_type) != 0)
1425 				) {
1426 				/* Don't set SE_SHUTDOWN here */
1427 				sp->se_nspace = 0;
1428 				sp->se_started = 0;
1429 				kill(sp->se_process, SIGHUP);
1430 			}
1431 			if (old_getty)
1432 				free(old_getty);
1433 			if (old_window)
1434 				free(old_window);
1435 			if (old_type)
1436 				free(old_type);
1437 			continue;
1438 		}
1439 
1440 		new_session(sprev, session_index, typ);
1441 	}
1442 
1443 	endttyent();
1444 
1445 	/*
1446 	 * sweep through and kill all deleted sessions
1447 	 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1448 	 */
1449 	for (sp = sessions; sp != NULL; sp = sp->se_next) {
1450 		if ((sp->se_flags & SE_PRESENT) == 0) {
1451 			sp->se_flags |= SE_SHUTDOWN;
1452 			kill(sp->se_process, SIGHUP);
1453 		}
1454 	}
1455 
1456 	return (state_func_t) multi_user;
1457 }
1458 
1459 /*
1460  * Block further logins.
1461  */
1462 state_func_t
1463 catatonia(void)
1464 {
1465 	session_t *sp;
1466 
1467 	for (sp = sessions; sp; sp = sp->se_next)
1468 		sp->se_flags |= SE_SHUTDOWN;
1469 
1470 	return (state_func_t) multi_user;
1471 }
1472 
1473 /*
1474  * Note SIGALRM.
1475  */
1476 void
1477 alrm_handler(int sig)
1478 {
1479 	(void)sig;
1480 	clang = 1;
1481 }
1482 
1483 /*
1484  * Bring the system down to single user.
1485  */
1486 state_func_t
1487 death(void)
1488 {
1489 	session_t *sp;
1490 	int i;
1491 	pid_t pid;
1492 	static const int death_sigs[2] = { SIGTERM, SIGKILL };
1493 
1494 	/* NB: should send a message to the session logger to avoid blocking. */
1495 	logwtmp("~", "shutdown", "");
1496 
1497 	for (sp = sessions; sp; sp = sp->se_next) {
1498 		sp->se_flags |= SE_SHUTDOWN;
1499 		kill(sp->se_process, SIGHUP);
1500 	}
1501 
1502 	/* Try to run the rc.shutdown script within a period of time */
1503 	(void) runshutdown();
1504 
1505 	for (i = 0; i < 2; ++i) {
1506 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1507 			return (state_func_t) single_user;
1508 
1509 		clang = 0;
1510 		alarm(DEATH_WATCH);
1511 		do
1512 			if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1513 				collect_child(pid);
1514 		while (clang == 0 && errno != ECHILD);
1515 
1516 		if (errno == ECHILD)
1517 			return (state_func_t) single_user;
1518 	}
1519 
1520 	warning("some processes would not die; ps axl advised");
1521 
1522 	return (state_func_t) single_user;
1523 }
1524 
1525 /*
1526  * Run the system shutdown script.
1527  *
1528  * Exit codes:      XXX I should document more
1529  * -2       shutdown script terminated abnormally
1530  * -1       fatal error - can't run script
1531  * 0        good.
1532  * >0       some error (exit code)
1533  */
1534 int
1535 runshutdown(void)
1536 {
1537 	pid_t pid, wpid;
1538 	int status;
1539 	int shutdowntimeout;
1540 	size_t len;
1541 	char *argv[4];
1542 	const char *shell;
1543 	struct sigaction sa;
1544 	struct stat sb;
1545 
1546 	/*
1547 	 * rc.shutdown is optional, so to prevent any unnecessary
1548 	 * complaints from the shell we simply don't run it if the
1549 	 * file does not exist. If the stat() here fails for other
1550 	 * reasons, we'll let the shell complain.
1551 	 */
1552 	if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1553 		return 0;
1554 
1555 	shell = get_shell();
1556 
1557 	if ((pid = fork()) == 0) {
1558 		int	fd;
1559 
1560 		/* Assume that init already grab console as ctty before */
1561 
1562 		sigemptyset(&sa.sa_mask);
1563 		sa.sa_flags = 0;
1564 		sa.sa_handler = SIG_IGN;
1565 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1566 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
1567 
1568 		if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1569 		    warning("can't open %s: %m", _PATH_CONSOLE);
1570 		else {
1571 		    (void) dup2(fd, 0);
1572 		    (void) dup2(fd, 1);
1573 		    (void) dup2(fd, 2);
1574 		    if (fd > 2)
1575 			close(fd);
1576 		}
1577 
1578 		/*
1579 		 * Run the shutdown script.
1580 		 */
1581 
1582 		char _sh[]	= "sh";
1583 		char _reboot[]	= "reboot";
1584 		char _single[]	= "single";
1585 		char _path_rundown[] = _PATH_RUNDOWN;
1586 
1587 		argv[0] = _sh;
1588 		argv[1] = _path_rundown;
1589 		argv[2] = Reboot ? _reboot : _single;
1590 		argv[3] = 0;
1591 
1592 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1593 
1594 #ifdef LOGIN_CAP
1595 		setprocresources(RESOURCE_RC);
1596 #endif
1597 		execv(shell, argv);
1598 		warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN);
1599 		_exit(1);	/* force single user mode */
1600 	}
1601 
1602 	if (pid == -1) {
1603 		emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN);
1604 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1605 			continue;
1606 		sleep(STALL_TIMEOUT);
1607 		return -1;
1608 	}
1609 
1610 	len = sizeof(shutdowntimeout);
1611 	if (sysctlbyname("kern.init_shutdown_timeout",
1612 			 &shutdowntimeout,
1613 			 &len, NULL, 0) == -1 || shutdowntimeout < 2)
1614 	    shutdowntimeout = DEATH_SCRIPT;
1615 	alarm(shutdowntimeout);
1616 	clang = 0;
1617 	/*
1618 	 * Copied from single_user().  This is a bit paranoid.
1619 	 * Use the same ALRM handler.
1620 	 */
1621 	do {
1622 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1623 			collect_child(wpid);
1624 		if (clang == 1) {
1625 			/* we were waiting for the sub-shell */
1626 			kill(wpid, SIGTERM);
1627 			warning("timeout expired for %s on %s: %m; going to "
1628 			    "single user mode", shell, _PATH_RUNDOWN);
1629 			return -1;
1630 		}
1631 		if (wpid == -1) {
1632 			if (errno == EINTR)
1633 				continue;
1634 			warning("wait for %s on %s failed: %m; going to "
1635 			    "single user mode", shell, _PATH_RUNDOWN);
1636 			return -1;
1637 		}
1638 		if (wpid == pid && WIFSTOPPED(status)) {
1639 			warning("init: %s on %s stopped, restarting\n",
1640 				shell, _PATH_RUNDOWN);
1641 			kill(pid, SIGCONT);
1642 			wpid = -1;
1643 		}
1644 	} while (wpid != pid && !clang);
1645 
1646 	/* Turn off the alarm */
1647 	alarm(0);
1648 
1649 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1650 	    requested_transition == catatonia) {
1651 		/*
1652 		 * /etc/rc.shutdown executed /sbin/reboot;
1653 		 * wait for the end quietly
1654 		 */
1655 		sigset_t s;
1656 
1657 		sigfillset(&s);
1658 		for (;;)
1659 			sigsuspend(&s);
1660 	}
1661 
1662 	if (!WIFEXITED(status)) {
1663 		warning("%s on %s terminated abnormally, going to "
1664 		    "single user mode", shell, _PATH_RUNDOWN);
1665 		return -2;
1666 	}
1667 
1668 	if ((status = WEXITSTATUS(status)) != 0)
1669 		warning("%s returned status %d", _PATH_RUNDOWN, status);
1670 
1671 	return status;
1672 }
1673 
1674 static char *
1675 strk(char *p)
1676 {
1677     static char *t;
1678     char *q;
1679     int c;
1680 
1681     if (p)
1682 	t = p;
1683     if (!t)
1684 	return 0;
1685 
1686     c = *t;
1687     while (c == ' ' || c == '\t' )
1688 	c = *++t;
1689     if (!c) {
1690 	t = 0;
1691 	return 0;
1692     }
1693     q = t;
1694     if (c == '\'') {
1695 	c = *++t;
1696 	q = t;
1697 	while (c && c != '\'')
1698 	    c = *++t;
1699 	if (!c)  /* unterminated string */
1700 	    q = t = 0;
1701 	else
1702 	    *t++ = 0;
1703     } else {
1704 	while (c && c != ' ' && c != '\t' )
1705 	    c = *++t;
1706 	*t++ = 0;
1707 	if (!c)
1708 	    t = 0;
1709     }
1710     return q;
1711 }
1712 
1713 #ifdef LOGIN_CAP
1714 void
1715 setprocresources(const char *cname)
1716 {
1717 	login_cap_t *lc;
1718 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1719 		setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1720 		login_close(lc);
1721 	}
1722 }
1723 #endif
1724