xref: /freebsd/sbin/init/init.c (revision a1a4f1a0d87b594d3f17a97dc0127eec1417e6f6)
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  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1991, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)init.c	8.1 (Berkeley) 7/15/93";
46 #endif
47 static const char rcsid[] =
48   "$FreeBSD$";
49 #endif /* not lint */
50 
51 #include <sys/param.h>
52 #include <sys/ioctl.h>
53 #include <sys/mount.h>
54 #include <sys/sysctl.h>
55 #include <sys/wait.h>
56 #include <sys/types.h>
57 #include <sys/stat.h>
58 
59 #include <db.h>
60 #include <errno.h>
61 #include <fcntl.h>
62 #include <libutil.h>
63 #include <signal.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #include <syslog.h>
68 #include <time.h>
69 #include <ttyent.h>
70 #include <unistd.h>
71 #include <sys/reboot.h>
72 #include <err.h>
73 
74 #ifdef __STDC__
75 #include <stdarg.h>
76 #else
77 #include <varargs.h>
78 #endif
79 
80 #ifdef SECURE
81 #include <pwd.h>
82 #endif
83 
84 #ifdef LOGIN_CAP
85 #include <login_cap.h>
86 #endif
87 
88 #include "pathnames.h"
89 
90 /*
91  * Sleep times; used to prevent thrashing.
92  */
93 #define	GETTY_SPACING		 5	/* N secs minimum getty spacing */
94 #define	GETTY_SLEEP		30	/* sleep N secs after spacing problem */
95 #define GETTY_NSPACE             3      /* max. spacing count to bring reaction */
96 #define	WINDOW_WAIT		 3	/* wait N secs after starting window */
97 #define	STALL_TIMEOUT		30	/* wait N secs after warning */
98 #define	DEATH_WATCH		10	/* wait N secs for procs to die */
99 #define DEATH_SCRIPT		120	/* wait for 2min for /etc/rc.shutdown */
100 #define RESOURCE_RC		"daemon"
101 #define RESOURCE_WINDOW 	"default"
102 #define RESOURCE_GETTY		"default"
103 
104 void handle __P((sig_t, ...));
105 void delset __P((sigset_t *, ...));
106 
107 void stall __P((char *, ...));
108 void warning __P((char *, ...));
109 void emergency __P((char *, ...));
110 void disaster __P((int));
111 void badsys __P((int));
112 int  runshutdown __P((void));
113 
114 /*
115  * We really need a recursive typedef...
116  * The following at least guarantees that the return type of (*state_t)()
117  * is sufficiently wide to hold a function pointer.
118  */
119 typedef long (*state_func_t) __P((void));
120 typedef state_func_t (*state_t) __P((void));
121 
122 state_func_t single_user __P((void));
123 state_func_t runcom __P((void));
124 state_func_t read_ttys __P((void));
125 state_func_t multi_user __P((void));
126 state_func_t clean_ttys __P((void));
127 state_func_t catatonia __P((void));
128 state_func_t death __P((void));
129 
130 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
131 #define FALSE	0
132 #define TRUE	1
133 
134 int Reboot = FALSE;
135 int howto = RB_AUTOBOOT;
136 
137 int devfs;
138 
139 void transition __P((state_t));
140 state_t requested_transition = runcom;
141 
142 void setctty __P((char *));
143 
144 typedef struct init_session {
145 	int	se_index;		/* index of entry in ttys file */
146 	pid_t	se_process;		/* controlling process */
147 	time_t	se_started;		/* used to avoid thrashing */
148 	int	se_flags;		/* status of session */
149 #define	SE_SHUTDOWN	0x1		/* session won't be restarted */
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 __P((session_t *));
164 session_t *new_session __P((session_t *, int, struct ttyent *));
165 session_t *sessions;
166 
167 char **construct_argv __P((char *));
168 void start_window_system __P((session_t *));
169 void collect_child __P((pid_t));
170 pid_t start_getty __P((session_t *));
171 void transition_handler __P((int));
172 void alrm_handler __P((int));
173 void setsecuritylevel __P((int));
174 int getsecuritylevel __P((void));
175 int setupargv __P((session_t *, struct ttyent *));
176 #ifdef LOGIN_CAP
177 void setprocresources __P((const char *));
178 #endif
179 int clang;
180 
181 void clear_session_logs __P((session_t *));
182 
183 int start_session_db __P((void));
184 void add_session __P((session_t *));
185 void del_session __P((session_t *));
186 session_t *find_session __P((pid_t));
187 DB *session_db;
188 
189 /*
190  * The mother of all processes.
191  */
192 int
193 main(argc, argv)
194 	int argc;
195 	char **argv;
196 {
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 				register char runlevel = *argv[1];
213 				register 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 			requested_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 	if (devfs) {
286 		mount("devfs", "/dev", MNT_NOEXEC|MNT_RDONLY, 0);
287 	}
288 
289 	/*
290 	 * We catch or block signals rather than ignore them,
291 	 * so that they get reset on exec.
292 	 */
293 	handle(badsys, SIGSYS, 0);
294 	handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
295 	       SIGBUS, SIGXCPU, SIGXFSZ, 0);
296 	handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP,
297 		SIGUSR1, SIGUSR2, 0);
298 	handle(alrm_handler, SIGALRM, 0);
299 	sigfillset(&mask);
300 	delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
301 		SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
302 		SIGUSR1, SIGUSR2, 0);
303 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
304 	sigemptyset(&sa.sa_mask);
305 	sa.sa_flags = 0;
306 	sa.sa_handler = SIG_IGN;
307 	(void) sigaction(SIGTTIN, &sa, (struct sigaction *)0);
308 	(void) sigaction(SIGTTOU, &sa, (struct sigaction *)0);
309 
310 	/*
311 	 * Paranoia.
312 	 */
313 	close(0);
314 	close(1);
315 	close(2);
316 
317 	/*
318 	 * Start the state machine.
319 	 */
320 	transition(requested_transition);
321 
322 	/*
323 	 * Should never reach here.
324 	 */
325 	return 1;
326 }
327 
328 /*
329  * Associate a function with a signal handler.
330  */
331 void
332 #ifdef __STDC__
333 handle(sig_t handler, ...)
334 #else
335 handle(va_alist)
336 	va_dcl
337 #endif
338 {
339 	int sig;
340 	struct sigaction sa;
341 	sigset_t mask_everything;
342 	va_list ap;
343 #ifndef __STDC__
344 	sig_t handler;
345 
346 	va_start(ap);
347 	handler = va_arg(ap, sig_t);
348 #else
349 	va_start(ap, handler);
350 #endif
351 
352 	sa.sa_handler = handler;
353 	sigfillset(&mask_everything);
354 
355 	while ((sig = va_arg(ap, int)) != NULL) {
356 		sa.sa_mask = mask_everything;
357 		/* XXX SA_RESTART? */
358 		sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
359 		sigaction(sig, &sa, (struct sigaction *) 0);
360 	}
361 	va_end(ap);
362 }
363 
364 /*
365  * Delete a set of signals from a mask.
366  */
367 void
368 #ifdef __STDC__
369 delset(sigset_t *maskp, ...)
370 #else
371 delset(va_alist)
372 	va_dcl
373 #endif
374 {
375 	int sig;
376 	va_list ap;
377 #ifndef __STDC__
378 	sigset_t *maskp;
379 
380 	va_start(ap);
381 	maskp = va_arg(ap, sigset_t *);
382 #else
383 	va_start(ap, maskp);
384 #endif
385 
386 	while ((sig = va_arg(ap, int)) != NULL)
387 		sigdelset(maskp, sig);
388 	va_end(ap);
389 }
390 
391 /*
392  * Log a message and sleep for a while (to give someone an opportunity
393  * to read it and to save log or hardcopy output if the problem is chronic).
394  * NB: should send a message to the session logger to avoid blocking.
395  */
396 void
397 #ifdef __STDC__
398 stall(char *message, ...)
399 #else
400 stall(va_alist)
401 	va_dcl
402 #endif
403 {
404 	va_list ap;
405 #ifndef __STDC__
406 	char *message;
407 
408 	va_start(ap);
409 	message = va_arg(ap, char *);
410 #else
411 	va_start(ap, message);
412 #endif
413 
414 	vsyslog(LOG_ALERT, message, ap);
415 	va_end(ap);
416 	sleep(STALL_TIMEOUT);
417 }
418 
419 /*
420  * Like stall(), but doesn't sleep.
421  * If cpp had variadic macros, the two functions could be #defines for another.
422  * NB: should send a message to the session logger to avoid blocking.
423  */
424 void
425 #ifdef __STDC__
426 warning(char *message, ...)
427 #else
428 warning(va_alist)
429 	va_dcl
430 #endif
431 {
432 	va_list ap;
433 #ifndef __STDC__
434 	char *message;
435 
436 	va_start(ap);
437 	message = va_arg(ap, char *);
438 #else
439 	va_start(ap, message);
440 #endif
441 
442 	vsyslog(LOG_ALERT, message, ap);
443 	va_end(ap);
444 }
445 
446 /*
447  * Log an emergency message.
448  * NB: should send a message to the session logger to avoid blocking.
449  */
450 void
451 #ifdef __STDC__
452 emergency(char *message, ...)
453 #else
454 emergency(va_alist)
455 	va_dcl
456 #endif
457 {
458 	va_list ap;
459 #ifndef __STDC__
460 	char *message;
461 
462 	va_start(ap);
463 	message = va_arg(ap, char *);
464 #else
465 	va_start(ap, message);
466 #endif
467 
468 	vsyslog(LOG_EMERG, message, ap);
469 	va_end(ap);
470 }
471 
472 /*
473  * Catch a SIGSYS signal.
474  *
475  * These may arise if a system does not support sysctl.
476  * We tolerate up to 25 of these, then throw in the towel.
477  */
478 void
479 badsys(sig)
480 	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(sig)
494 	int sig;
495 {
496 	emergency("fatal signal: %s",
497 		(unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
498 
499 	sleep(STALL_TIMEOUT);
500 	_exit(sig);		/* reboot */
501 }
502 
503 /*
504  * Get the security level of the kernel.
505  */
506 int
507 getsecuritylevel()
508 {
509 #ifdef KERN_SECURELVL
510 	int name[2], curlevel;
511 	size_t len;
512 	extern int errno;
513 
514 	name[0] = CTL_KERN;
515 	name[1] = KERN_SECURELVL;
516 	len = sizeof curlevel;
517 	if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
518 		emergency("cannot get kernel security level: %s",
519 		    strerror(errno));
520 		return (-1);
521 	}
522 	return (curlevel);
523 #else
524 	return (-1);
525 #endif
526 }
527 
528 /*
529  * Set the security level of the kernel.
530  */
531 void
532 setsecuritylevel(newlevel)
533 	int newlevel;
534 {
535 #ifdef KERN_SECURELVL
536 	int name[2], curlevel;
537 	extern int errno;
538 
539 	curlevel = getsecuritylevel();
540 	if (newlevel == curlevel)
541 		return;
542 	name[0] = CTL_KERN;
543 	name[1] = KERN_SECURELVL;
544 	if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
545 		emergency(
546 		    "cannot change kernel security level from %d to %d: %s",
547 		    curlevel, newlevel, strerror(errno));
548 		return;
549 	}
550 #ifdef SECURE
551 	warning("kernel security level changed from %d to %d",
552 	    curlevel, newlevel);
553 #endif
554 #endif
555 }
556 
557 /*
558  * Change states in the finite state machine.
559  * The initial state is passed as an argument.
560  */
561 void
562 transition(s)
563 	state_t s;
564 {
565 	for (;;)
566 		s = (state_t) (*s)();
567 }
568 
569 /*
570  * Close out the accounting files for a login session.
571  * NB: should send a message to the session logger to avoid blocking.
572  */
573 void
574 clear_session_logs(sp)
575 	session_t *sp;
576 {
577 	char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
578 
579 	if (logout(line))
580 		logwtmp(line, "", "");
581 }
582 
583 /*
584  * Start a session and allocate a controlling terminal.
585  * Only called by children of init after forking.
586  */
587 void
588 setctty(name)
589 	char *name;
590 {
591 	int fd;
592 
593 	(void) revoke(name);
594 	if ((fd = open(name, O_RDWR)) == -1) {
595 		stall("can't open %s: %m", name);
596 		_exit(1);
597 	}
598 	if (login_tty(fd) == -1) {
599 		stall("can't get %s for controlling terminal: %m", name);
600 		_exit(1);
601 	}
602 }
603 
604 /*
605  * Bring the system up single user.
606  */
607 state_func_t
608 single_user()
609 {
610 	pid_t pid, wpid;
611 	int status;
612 	sigset_t mask;
613 	char *shell = _PATH_BSHELL;
614 	char *argv[2];
615 #ifdef SECURE
616 	struct ttyent *typ;
617 	struct passwd *pp;
618 	static const char banner[] =
619 		"Enter root password, or ^D to go multi-user\n";
620 	char *clear, *password;
621 #endif
622 #ifdef DEBUGSHELL
623 	char altshell[128];
624 #endif
625 
626 	/*
627 	 * If the kernel is in secure mode, downgrade it to insecure mode.
628 	 */
629 	if (getsecuritylevel() > 0)
630 		setsecuritylevel(0);
631 
632 	if (Reboot) {
633 		/* Instead of going single user, let's reboot the machine */
634 		sync();
635 		alarm(2);
636 		pause();
637 		reboot(howto);
638 		_exit(0);
639 	}
640 
641 	if ((pid = fork()) == 0) {
642 		/*
643 		 * Start the single user session.
644 		 */
645 		setctty(_PATH_CONSOLE);
646 
647 #ifdef SECURE
648 		/*
649 		 * Check the root password.
650 		 * We don't care if the console is 'on' by default;
651 		 * it's the only tty that can be 'off' and 'secure'.
652 		 */
653 		typ = getttynam("console");
654 		pp = getpwnam("root");
655 		if (typ && (typ->ty_status & TTY_SECURE) == 0 && pp && *pp->pw_passwd) {
656 			write(2, banner, sizeof banner - 1);
657 			for (;;) {
658 				clear = getpass("Password:");
659 				if (clear == 0 || *clear == '\0')
660 					_exit(0);
661 				password = crypt(clear, pp->pw_passwd);
662 				bzero(clear, _PASSWORD_LEN);
663 				if (strcmp(password, pp->pw_passwd) == 0)
664 					break;
665 				warning("single-user login failed\n");
666 			}
667 		}
668 		endttyent();
669 		endpwent();
670 #endif /* SECURE */
671 
672 #ifdef DEBUGSHELL
673 		{
674 			char *cp = altshell;
675 			int num;
676 
677 #define	SHREQUEST \
678 	"Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
679 			(void)write(STDERR_FILENO,
680 			    SHREQUEST, sizeof(SHREQUEST) - 1);
681 			while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
682 			    num != 0 && *cp != '\n' && cp < &altshell[127])
683 					cp++;
684 			*cp = '\0';
685 			if (altshell[0] != '\0')
686 				shell = altshell;
687 		}
688 #endif /* DEBUGSHELL */
689 
690 		/*
691 		 * Unblock signals.
692 		 * We catch all the interesting ones,
693 		 * and those are reset to SIG_DFL on exec.
694 		 */
695 		sigemptyset(&mask);
696 		sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
697 
698 		/*
699 		 * Fire off a shell.
700 		 * If the default one doesn't work, try the Bourne shell.
701 		 */
702 		argv[0] = "-sh";
703 		argv[1] = 0;
704 		execv(shell, argv);
705 		emergency("can't exec %s for single user: %m", shell);
706 		execv(_PATH_BSHELL, argv);
707 		emergency("can't exec %s for single user: %m", _PATH_BSHELL);
708 		sleep(STALL_TIMEOUT);
709 		_exit(1);
710 	}
711 
712 	if (pid == -1) {
713 		/*
714 		 * We are seriously hosed.  Do our best.
715 		 */
716 		emergency("can't fork single-user shell, trying again");
717 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
718 			continue;
719 		return (state_func_t) single_user;
720 	}
721 
722 	requested_transition = 0;
723 	do {
724 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
725 			collect_child(wpid);
726 		if (wpid == -1) {
727 			if (errno == EINTR)
728 				continue;
729 			warning("wait for single-user shell failed: %m; restarting");
730 			return (state_func_t) single_user;
731 		}
732 		if (wpid == pid && WIFSTOPPED(status)) {
733 			warning("init: shell stopped, restarting\n");
734 			kill(pid, SIGCONT);
735 			wpid = -1;
736 		}
737 	} while (wpid != pid && !requested_transition);
738 
739 	if (requested_transition)
740 		return (state_func_t) requested_transition;
741 
742 	if (!WIFEXITED(status)) {
743 		if (WTERMSIG(status) == SIGKILL) {
744 			/*
745 			 *  reboot(8) killed shell?
746 			 */
747 			warning("single user shell terminated.");
748 			sleep(STALL_TIMEOUT);
749 			_exit(0);
750 		} else {
751 			warning("single user shell terminated, restarting");
752 			return (state_func_t) single_user;
753 		}
754 	}
755 
756 	runcom_mode = FASTBOOT;
757 	return (state_func_t) runcom;
758 }
759 
760 /*
761  * Run the system startup script.
762  */
763 state_func_t
764 runcom()
765 {
766 	pid_t pid, wpid;
767 	int status;
768 	char *argv[4];
769 	struct sigaction sa;
770 
771 	if ((pid = fork()) == 0) {
772 		sigemptyset(&sa.sa_mask);
773 		sa.sa_flags = 0;
774 		sa.sa_handler = SIG_IGN;
775 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
776 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
777 
778 		setctty(_PATH_CONSOLE);
779 
780 		argv[0] = "sh";
781 		argv[1] = _PATH_RUNCOM;
782 		argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
783 		argv[3] = 0;
784 
785 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
786 
787 #ifdef LOGIN_CAP
788 		setprocresources(RESOURCE_RC);
789 #endif
790 		execv(_PATH_BSHELL, argv);
791 		stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
792 		_exit(1);	/* force single user mode */
793 	}
794 
795 	if (pid == -1) {
796 		emergency("can't fork for %s on %s: %m",
797 			_PATH_BSHELL, _PATH_RUNCOM);
798 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
799 			continue;
800 		sleep(STALL_TIMEOUT);
801 		return (state_func_t) single_user;
802 	}
803 
804 	/*
805 	 * Copied from single_user().  This is a bit paranoid.
806 	 */
807 	do {
808 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
809 			collect_child(wpid);
810 		if (wpid == -1) {
811 			if (errno == EINTR)
812 				continue;
813 			warning("wait for %s on %s failed: %m; going to single user mode",
814 				_PATH_BSHELL, _PATH_RUNCOM);
815 			return (state_func_t) single_user;
816 		}
817 		if (wpid == pid && WIFSTOPPED(status)) {
818 			warning("init: %s on %s stopped, restarting\n",
819 				_PATH_BSHELL, _PATH_RUNCOM);
820 			kill(pid, SIGCONT);
821 			wpid = -1;
822 		}
823 	} while (wpid != pid);
824 
825 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
826 	    requested_transition == catatonia) {
827 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
828 		sigset_t s;
829 
830 		sigfillset(&s);
831 		for (;;)
832 			sigsuspend(&s);
833 	}
834 
835 	if (!WIFEXITED(status)) {
836 		warning("%s on %s terminated abnormally, going to single user mode",
837 			_PATH_BSHELL, _PATH_RUNCOM);
838 		return (state_func_t) single_user;
839 	}
840 
841 	if (WEXITSTATUS(status))
842 		return (state_func_t) single_user;
843 
844 	runcom_mode = AUTOBOOT;		/* the default */
845 	/* NB: should send a message to the session logger to avoid blocking. */
846 	logwtmp("~", "reboot", "");
847 	return (state_func_t) read_ttys;
848 }
849 
850 /*
851  * Open the session database.
852  *
853  * NB: We could pass in the size here; is it necessary?
854  */
855 int
856 start_session_db()
857 {
858 	if (session_db && (*session_db->close)(session_db))
859 		emergency("session database close: %s", strerror(errno));
860 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
861 		emergency("session database open: %s", strerror(errno));
862 		return (1);
863 	}
864 	return (0);
865 
866 }
867 
868 /*
869  * Add a new login session.
870  */
871 void
872 add_session(sp)
873 	session_t *sp;
874 {
875 	DBT key;
876 	DBT data;
877 
878 	key.data = &sp->se_process;
879 	key.size = sizeof sp->se_process;
880 	data.data = &sp;
881 	data.size = sizeof sp;
882 
883 	if ((*session_db->put)(session_db, &key, &data, 0))
884 		emergency("insert %d: %s", sp->se_process, strerror(errno));
885 }
886 
887 /*
888  * Delete an old login session.
889  */
890 void
891 del_session(sp)
892 	session_t *sp;
893 {
894 	DBT key;
895 
896 	key.data = &sp->se_process;
897 	key.size = sizeof sp->se_process;
898 
899 	if ((*session_db->del)(session_db, &key, 0))
900 		emergency("delete %d: %s", sp->se_process, strerror(errno));
901 }
902 
903 /*
904  * Look up a login session by pid.
905  */
906 session_t *
907 #ifdef __STDC__
908 find_session(pid_t pid)
909 #else
910 find_session(pid)
911 	pid_t pid;
912 #endif
913 {
914 	DBT key;
915 	DBT data;
916 	session_t *ret;
917 
918 	key.data = &pid;
919 	key.size = sizeof pid;
920 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
921 		return 0;
922 	bcopy(data.data, (char *)&ret, sizeof(ret));
923 	return ret;
924 }
925 
926 /*
927  * Construct an argument vector from a command line.
928  */
929 char **
930 construct_argv(command)
931 	char *command;
932 {
933 	char *strk (char *);
934 	register int argc = 0;
935 	register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
936 						* sizeof (char *));
937 
938 	if ((argv[argc++] = strk(command)) == 0) {
939 		free(argv);
940 		return (NULL);
941 	}
942 	while ((argv[argc++] = strk((char *) 0)) != NULL)
943 		continue;
944 	return argv;
945 }
946 
947 /*
948  * Deallocate a session descriptor.
949  */
950 void
951 free_session(sp)
952 	register session_t *sp;
953 {
954 	free(sp->se_device);
955 	if (sp->se_getty) {
956 		free(sp->se_getty);
957 		free(sp->se_getty_argv_space);
958 		free(sp->se_getty_argv);
959 	}
960 	if (sp->se_window) {
961 		free(sp->se_window);
962 		free(sp->se_window_argv_space);
963 		free(sp->se_window_argv);
964 	}
965 	if (sp->se_type)
966 		free(sp->se_type);
967 	free(sp);
968 }
969 
970 /*
971  * Allocate a new session descriptor.
972  */
973 session_t *
974 new_session(sprev, session_index, typ)
975 	session_t *sprev;
976 	int session_index;
977 	register struct ttyent *typ;
978 {
979 	register session_t *sp;
980 	int fd;
981 
982 	if ((typ->ty_status & TTY_ON) == 0 ||
983 	    typ->ty_name == 0 ||
984 	    typ->ty_getty == 0)
985 		return 0;
986 
987 	sp = (session_t *) calloc(1, sizeof (session_t));
988 
989 	sp->se_index = session_index;
990 
991 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
992 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
993 
994 	/*
995 	 * Attempt to open the device, if we get "device not configured"
996 	 * then don't add the device to the session list.
997 	 */
998 	if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
999 		if (errno == ENXIO) {
1000 			free_session(sp);
1001 			return (0);
1002 		}
1003 	} else
1004 		close(fd);
1005 
1006 	if (setupargv(sp, typ) == 0) {
1007 		free_session(sp);
1008 		return (0);
1009 	}
1010 
1011 	sp->se_next = 0;
1012 	if (sprev == 0) {
1013 		sessions = sp;
1014 		sp->se_prev = 0;
1015 	} else {
1016 		sprev->se_next = sp;
1017 		sp->se_prev = sprev;
1018 	}
1019 
1020 	return sp;
1021 }
1022 
1023 /*
1024  * Calculate getty and if useful window argv vectors.
1025  */
1026 int
1027 setupargv(sp, typ)
1028 	session_t *sp;
1029 	struct ttyent *typ;
1030 {
1031 
1032 	if (sp->se_getty) {
1033 		free(sp->se_getty);
1034 		free(sp->se_getty_argv_space);
1035 		free(sp->se_getty_argv);
1036 	}
1037 	sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1038 	(void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1039 	sp->se_getty_argv_space = strdup(sp->se_getty);
1040 	sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1041 	if (sp->se_getty_argv == 0) {
1042 		warning("can't parse getty for port %s", sp->se_device);
1043 		free(sp->se_getty);
1044 		free(sp->se_getty_argv_space);
1045 		sp->se_getty = sp->se_getty_argv_space = 0;
1046 		return (0);
1047 	}
1048 	if (sp->se_window) {
1049 		free(sp->se_window);
1050 		free(sp->se_window_argv_space);
1051 		free(sp->se_window_argv);
1052 	}
1053 	sp->se_window = sp->se_window_argv_space = 0;
1054 	sp->se_window_argv = 0;
1055 	if (typ->ty_window) {
1056 		sp->se_window = strdup(typ->ty_window);
1057 		sp->se_window_argv_space = strdup(sp->se_window);
1058 		sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1059 		if (sp->se_window_argv == 0) {
1060 			warning("can't parse window for port %s",
1061 				sp->se_device);
1062 			free(sp->se_window_argv_space);
1063 			free(sp->se_window);
1064 			sp->se_window = sp->se_window_argv_space = 0;
1065 			return (0);
1066 		}
1067 	}
1068 	if (sp->se_type)
1069 		free(sp->se_type);
1070 	sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1071 	return (1);
1072 }
1073 
1074 /*
1075  * Walk the list of ttys and create sessions for each active line.
1076  */
1077 state_func_t
1078 read_ttys()
1079 {
1080 	int session_index = 0;
1081 	register session_t *sp, *snext;
1082 	register struct ttyent *typ;
1083 
1084 	/*
1085 	 * Destroy any previous session state.
1086 	 * There shouldn't be any, but just in case...
1087 	 */
1088 	for (sp = sessions; sp; sp = snext) {
1089 		if (sp->se_process)
1090 			clear_session_logs(sp);
1091 		snext = sp->se_next;
1092 		free_session(sp);
1093 	}
1094 	sessions = 0;
1095 	if (start_session_db())
1096 		return (state_func_t) single_user;
1097 
1098 	/*
1099 	 * Allocate a session entry for each active port.
1100 	 * Note that sp starts at 0.
1101 	 */
1102 	while ((typ = getttyent()) != NULL)
1103 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1104 			sp = snext;
1105 
1106 	endttyent();
1107 
1108 	return (state_func_t) multi_user;
1109 }
1110 
1111 /*
1112  * Start a window system running.
1113  */
1114 void
1115 start_window_system(sp)
1116 	session_t *sp;
1117 {
1118 	pid_t pid;
1119 	sigset_t mask;
1120 	char term[64], *env[2];
1121 
1122 	if ((pid = fork()) == -1) {
1123 		emergency("can't fork for window system on port %s: %m",
1124 			sp->se_device);
1125 		/* hope that getty fails and we can try again */
1126 		return;
1127 	}
1128 
1129 	if (pid)
1130 		return;
1131 
1132 	sigemptyset(&mask);
1133 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1134 
1135 	if (setsid() < 0)
1136 		emergency("setsid failed (window) %m");
1137 
1138 #ifdef LOGIN_CAP
1139 	setprocresources(RESOURCE_WINDOW);
1140 #endif
1141 	if (sp->se_type) {
1142 		/* Don't use malloc after fork */
1143 		strcpy(term, "TERM=");
1144 		strncat(term, sp->se_type, sizeof(term) - 6);
1145 		env[0] = term;
1146 		env[1] = 0;
1147 	}
1148 	else
1149 		env[0] = 0;
1150 	execve(sp->se_window_argv[0], sp->se_window_argv, env);
1151 	stall("can't exec window system '%s' for port %s: %m",
1152 		sp->se_window_argv[0], sp->se_device);
1153 	_exit(1);
1154 }
1155 
1156 /*
1157  * Start a login session running.
1158  */
1159 pid_t
1160 start_getty(sp)
1161 	session_t *sp;
1162 {
1163 	pid_t pid;
1164 	sigset_t mask;
1165 	time_t current_time = time((time_t *) 0);
1166 	int too_quick = 0;
1167 	char term[64], *env[2];
1168 
1169 	if (current_time >= sp->se_started &&
1170 	    current_time - sp->se_started < GETTY_SPACING) {
1171 		if (++sp->se_nspace > GETTY_NSPACE) {
1172 			sp->se_nspace = 0;
1173 			too_quick = 1;
1174 		}
1175 	} else
1176 		sp->se_nspace = 0;
1177 
1178 	/*
1179 	 * fork(), not vfork() -- we can't afford to block.
1180 	 */
1181 	if ((pid = fork()) == -1) {
1182 		emergency("can't fork for getty on port %s: %m", sp->se_device);
1183 		return -1;
1184 	}
1185 
1186 	if (pid)
1187 		return pid;
1188 
1189 	if (too_quick) {
1190 		warning("getty repeating too quickly on port %s, sleeping %d secs",
1191 			sp->se_device, GETTY_SLEEP);
1192 		sleep((unsigned) GETTY_SLEEP);
1193 	}
1194 
1195 	if (sp->se_window) {
1196 		start_window_system(sp);
1197 		sleep(WINDOW_WAIT);
1198 	}
1199 
1200 	sigemptyset(&mask);
1201 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1202 
1203 #ifdef LOGIN_CAP
1204 	setprocresources(RESOURCE_GETTY);
1205 #endif
1206 	if (sp->se_type) {
1207 		/* Don't use malloc after fork */
1208 		strcpy(term, "TERM=");
1209 		strncat(term, sp->se_type, sizeof(term) - 6);
1210 		env[0] = term;
1211 		env[1] = 0;
1212 	}
1213 	else
1214 		env[0] = 0;
1215 	execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1216 	stall("can't exec getty '%s' for port %s: %m",
1217 		sp->se_getty_argv[0], sp->se_device);
1218 	_exit(1);
1219 }
1220 
1221 /*
1222  * Collect exit status for a child.
1223  * If an exiting login, start a new login running.
1224  */
1225 void
1226 #ifdef __STDC__
1227 collect_child(pid_t pid)
1228 #else
1229 collect_child(pid)
1230 	pid_t pid;
1231 #endif
1232 {
1233 	register session_t *sp, *sprev, *snext;
1234 
1235 	if (! sessions)
1236 		return;
1237 
1238 	if (! (sp = find_session(pid)))
1239 		return;
1240 
1241 	clear_session_logs(sp);
1242 	del_session(sp);
1243 	sp->se_process = 0;
1244 
1245 	if (sp->se_flags & SE_SHUTDOWN) {
1246 		if ((sprev = sp->se_prev) != NULL)
1247 			sprev->se_next = sp->se_next;
1248 		else
1249 			sessions = sp->se_next;
1250 		if ((snext = sp->se_next) != NULL)
1251 			snext->se_prev = sp->se_prev;
1252 		free_session(sp);
1253 		return;
1254 	}
1255 
1256 	if ((pid = start_getty(sp)) == -1) {
1257 		/* serious trouble */
1258 		requested_transition = clean_ttys;
1259 		return;
1260 	}
1261 
1262 	sp->se_process = pid;
1263 	sp->se_started = time((time_t *) 0);
1264 	add_session(sp);
1265 }
1266 
1267 /*
1268  * Catch a signal and request a state transition.
1269  */
1270 void
1271 transition_handler(sig)
1272 	int sig;
1273 {
1274 
1275 	switch (sig) {
1276 	case SIGHUP:
1277 		requested_transition = clean_ttys;
1278 		break;
1279 	case SIGUSR2:
1280 		howto = RB_POWEROFF;
1281 	case SIGUSR1:
1282 		howto |= RB_HALT;
1283 	case SIGINT:
1284 		Reboot = TRUE;
1285 	case SIGTERM:
1286 		requested_transition = death;
1287 		break;
1288 	case SIGTSTP:
1289 		requested_transition = catatonia;
1290 		break;
1291 	default:
1292 		requested_transition = 0;
1293 		break;
1294 	}
1295 }
1296 
1297 /*
1298  * Take the system multiuser.
1299  */
1300 state_func_t
1301 multi_user()
1302 {
1303 	pid_t pid;
1304 	register session_t *sp;
1305 
1306 	requested_transition = 0;
1307 
1308 	/*
1309 	 * If the administrator has not set the security level to -1
1310 	 * to indicate that the kernel should not run multiuser in secure
1311 	 * mode, and the run script has not set a higher level of security
1312 	 * than level 1, then put the kernel into secure mode.
1313 	 */
1314 	if (getsecuritylevel() == 0)
1315 		setsecuritylevel(1);
1316 
1317 	for (sp = sessions; sp; sp = sp->se_next) {
1318 		if (sp->se_process)
1319 			continue;
1320 		if ((pid = start_getty(sp)) == -1) {
1321 			/* serious trouble */
1322 			requested_transition = clean_ttys;
1323 			break;
1324 		}
1325 		sp->se_process = pid;
1326 		sp->se_started = time((time_t *) 0);
1327 		add_session(sp);
1328 	}
1329 
1330 	while (!requested_transition)
1331 		if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1332 			collect_child(pid);
1333 
1334 	return (state_func_t) requested_transition;
1335 }
1336 
1337 /*
1338  * This is an n-squared algorithm.  We hope it isn't run often...
1339  */
1340 state_func_t
1341 clean_ttys()
1342 {
1343 	register session_t *sp, *sprev;
1344 	register struct ttyent *typ;
1345 	register int session_index = 0;
1346 	register int devlen;
1347 	char *old_getty, *old_window, *old_type;
1348 
1349 	if (! sessions)
1350 		return (state_func_t) multi_user;
1351 
1352 	devlen = sizeof(_PATH_DEV) - 1;
1353 	while ((typ = getttyent()) != NULL) {
1354 		++session_index;
1355 
1356 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1357 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1358 				break;
1359 
1360 		if (sp) {
1361 			if (sp->se_index != session_index) {
1362 				warning("port %s changed utmp index from %d to %d",
1363 				       sp->se_device, sp->se_index,
1364 				       session_index);
1365 				sp->se_index = session_index;
1366 			}
1367 			if ((typ->ty_status & TTY_ON) == 0 ||
1368 			    typ->ty_getty == 0) {
1369 				sp->se_flags |= SE_SHUTDOWN;
1370 				kill(sp->se_process, SIGHUP);
1371 				continue;
1372 			}
1373 			sp->se_flags &= ~SE_SHUTDOWN;
1374 			old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1375 			old_window = sp->se_window ? strdup(sp->se_window) : 0;
1376 			old_type = sp->se_type ? strdup(sp->se_type) : 0;
1377 			if (setupargv(sp, typ) == 0) {
1378 				warning("can't parse getty for port %s",
1379 					sp->se_device);
1380 				sp->se_flags |= SE_SHUTDOWN;
1381 				kill(sp->se_process, SIGHUP);
1382 			}
1383 			else if (   !old_getty
1384 				 || (!old_type && sp->se_type)
1385 				 || (old_type && !sp->se_type)
1386 				 || (!old_window && sp->se_window)
1387 				 || (old_window && !sp->se_window)
1388 				 || (strcmp(old_getty, sp->se_getty) != 0)
1389 				 || (old_window && strcmp(old_window, sp->se_window) != 0)
1390 				 || (old_type && strcmp(old_type, sp->se_type) != 0)
1391 				) {
1392 				/* Don't set SE_SHUTDOWN here */
1393 				sp->se_nspace = 0;
1394 				sp->se_started = 0;
1395 				kill(sp->se_process, SIGHUP);
1396 			}
1397 			if (old_getty)
1398 				free(old_getty);
1399 			if (old_getty)
1400 				free(old_window);
1401 			if (old_type)
1402 				free(old_type);
1403 			continue;
1404 		}
1405 
1406 		new_session(sprev, session_index, typ);
1407 	}
1408 
1409 	endttyent();
1410 
1411 	return (state_func_t) multi_user;
1412 }
1413 
1414 /*
1415  * Block further logins.
1416  */
1417 state_func_t
1418 catatonia()
1419 {
1420 	register session_t *sp;
1421 
1422 	for (sp = sessions; sp; sp = sp->se_next)
1423 		sp->se_flags |= SE_SHUTDOWN;
1424 
1425 	return (state_func_t) multi_user;
1426 }
1427 
1428 /*
1429  * Note SIGALRM.
1430  */
1431 void
1432 alrm_handler(sig)
1433 	int sig;
1434 {
1435 	(void)sig;
1436 	clang = 1;
1437 }
1438 
1439 /*
1440  * Bring the system down to single user.
1441  */
1442 state_func_t
1443 death()
1444 {
1445 	register session_t *sp;
1446 	register int i;
1447 	pid_t pid;
1448 	static const int death_sigs[2] = { SIGTERM, SIGKILL };
1449 
1450 	/* NB: should send a message to the session logger to avoid blocking. */
1451 	logwtmp("~", "shutdown", "");
1452 
1453 	for (sp = sessions; sp; sp = sp->se_next) {
1454 		sp->se_flags |= SE_SHUTDOWN;
1455 		kill(sp->se_process, SIGHUP);
1456 	}
1457 
1458 	/* Try to run the rc.shutdown script within a period of time */
1459 	(void) runshutdown();
1460 
1461 	for (i = 0; i < 2; ++i) {
1462 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1463 			return (state_func_t) single_user;
1464 
1465 		clang = 0;
1466 		alarm(DEATH_WATCH);
1467 		do
1468 			if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1469 				collect_child(pid);
1470 		while (clang == 0 && errno != ECHILD);
1471 
1472 		if (errno == ECHILD)
1473 			return (state_func_t) single_user;
1474 	}
1475 
1476 	warning("some processes would not die; ps axl advised");
1477 
1478 	return (state_func_t) single_user;
1479 }
1480 
1481 /*
1482  * Run the system shutdown script.
1483  *
1484  * Exit codes:      XXX I should document more
1485  * -2       shutdown script terminated abnormally
1486  * -1       fatal error - can't run script
1487  * 0        good.
1488  * >0       some error (exit code)
1489  */
1490 int
1491 runshutdown()
1492 {
1493 	pid_t pid, wpid;
1494 	int status;
1495 	int shutdowntimeout;
1496 	size_t len;
1497 	char *argv[3];
1498 	struct sigaction sa;
1499 	struct stat sb;
1500 
1501 	/*
1502 	 * rc.shutdown is optional, so to prevent any unnecessary
1503 	 * complaints from the shell we simply don't run it if the
1504 	 * file does not exist. If the stat() here fails for other
1505 	 * reasons, we'll let the shell complain.
1506 	 */
1507 	if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1508 		return 0;
1509 
1510 	if ((pid = fork()) == 0) {
1511 		int	fd;
1512 
1513 		/* Assume that init already grab console as ctty before */
1514 
1515 		sigemptyset(&sa.sa_mask);
1516 		sa.sa_flags = 0;
1517 		sa.sa_handler = SIG_IGN;
1518 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1519 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
1520 
1521 		if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1522 		    warning("can't open %s: %m", _PATH_CONSOLE);
1523 		else {
1524 		    (void) dup2(fd, 0);
1525 		    (void) dup2(fd, 1);
1526 		    (void) dup2(fd, 2);
1527 		    if (fd > 2)
1528 			close(fd);
1529 		}
1530 
1531 		/*
1532 		 * Run the shutdown script.
1533 		 */
1534 		argv[0] = "sh";
1535 		argv[1] = _PATH_RUNDOWN;
1536 		argv[2] = 0;
1537 
1538 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1539 
1540 #ifdef LOGIN_CAP
1541 		setprocresources(RESOURCE_RC);
1542 #endif
1543 		execv(_PATH_BSHELL, argv);
1544 		warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1545 		_exit(1);	/* force single user mode */
1546 	}
1547 
1548 	if (pid == -1) {
1549 		emergency("can't fork for %s on %s: %m",
1550 			_PATH_BSHELL, _PATH_RUNDOWN);
1551 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1552 			continue;
1553 		sleep(STALL_TIMEOUT);
1554 		return -1;
1555 	}
1556 
1557 	len = sizeof(shutdowntimeout);
1558 	if (sysctlbyname("kern.shutdown_timeout",
1559 			 &shutdowntimeout,
1560 			 &len, NULL, 0) == -1 || shutdowntimeout < 2)
1561 	    shutdowntimeout = DEATH_SCRIPT;
1562 	alarm(shutdowntimeout);
1563 	clang = 0;
1564 	/*
1565 	 * Copied from single_user().  This is a bit paranoid.
1566 	 * Use the same ALRM handler.
1567 	 */
1568 	do {
1569 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1570 			collect_child(wpid);
1571 		if (clang == 1) {
1572 			/* we were waiting for the sub-shell */
1573 			kill(wpid, SIGTERM);
1574 			warning("timeout expired for %s on %s: %m; going to single used mode",
1575 				_PATH_BSHELL, _PATH_RUNDOWN);
1576 			return -1;
1577 		}
1578 		if (wpid == -1) {
1579 			if (errno == EINTR)
1580 				continue;
1581 			warning("wait for %s on %s failed: %m; going to single user mode",
1582 				_PATH_BSHELL, _PATH_RUNDOWN);
1583 			return -1;
1584 		}
1585 		if (wpid == pid && WIFSTOPPED(status)) {
1586 			warning("init: %s on %s stopped, restarting\n",
1587 				_PATH_BSHELL, _PATH_RUNDOWN);
1588 			kill(pid, SIGCONT);
1589 			wpid = -1;
1590 		}
1591 	} while (wpid != pid && !clang);
1592 
1593 	/* Turn off the alarm */
1594 	alarm(0);
1595 
1596 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1597 	    requested_transition == catatonia) {
1598 		/*
1599 		 * /etc/rc.shutdown executed /sbin/reboot;
1600 		 * wait for the end quietly
1601 		 */
1602 		sigset_t s;
1603 
1604 		sigfillset(&s);
1605 		for (;;)
1606 			sigsuspend(&s);
1607 	}
1608 
1609 	if (!WIFEXITED(status)) {
1610 		warning("%s on %s terminated abnormally, going to single user mode",
1611 			_PATH_BSHELL, _PATH_RUNDOWN);
1612 		return -2;
1613 	}
1614 
1615 	if ((status = WEXITSTATUS(status)) != 0)
1616 		warning("%s returned status %d", _PATH_RUNDOWN, status);
1617 
1618 	return status;
1619 }
1620 
1621 char *
1622 strk (char *p)
1623 {
1624     static char *t;
1625     char *q;
1626     int c;
1627 
1628     if (p)
1629 	t = p;
1630     if (!t)
1631 	return 0;
1632 
1633     c = *t;
1634     while (c == ' ' || c == '\t' )
1635 	c = *++t;
1636     if (!c) {
1637 	t = 0;
1638 	return 0;
1639     }
1640     q = t;
1641     if (c == '\'') {
1642 	c = *++t;
1643 	q = t;
1644 	while (c && c != '\'')
1645 	    c = *++t;
1646 	if (!c)  /* unterminated string */
1647 	    q = t = 0;
1648 	else
1649 	    *t++ = 0;
1650     } else {
1651 	while (c && c != ' ' && c != '\t' )
1652 	    c = *++t;
1653 	*t++ = 0;
1654 	if (!c)
1655 	    t = 0;
1656     }
1657     return q;
1658 }
1659 
1660 #ifdef LOGIN_CAP
1661 void
1662 setprocresources(cname)
1663 	const char *cname;
1664 {
1665 	login_cap_t *lc;
1666 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1667 		setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1668 		login_close(lc);
1669 	}
1670 }
1671 #endif
1672