xref: /dragonfly/sbin/init/init.c (revision 6e285212)
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  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
37  * @(#)init.c	8.1 (Berkeley) 7/15/93
38  * $FreeBSD: src/sbin/init/init.c,v 1.38.2.8 2001/10/22 11:27:32 des Exp $
39  * $DragonFly: src/sbin/init/init.c,v 1.2 2003/06/17 04:27:33 dillon Exp $
40  */
41 
42 #include <sys/param.h>
43 #include <sys/ioctl.h>
44 #include <sys/mount.h>
45 #include <sys/sysctl.h>
46 #include <sys/wait.h>
47 #include <sys/stat.h>
48 
49 #include <db.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <libutil.h>
53 #include <paths.h>
54 #include <signal.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <syslog.h>
59 #include <time.h>
60 #include <ttyent.h>
61 #include <unistd.h>
62 #include <sys/reboot.h>
63 #include <err.h>
64 
65 #ifdef __STDC__
66 #include <stdarg.h>
67 #else
68 #include <varargs.h>
69 #endif
70 
71 #ifdef SECURE
72 #include <pwd.h>
73 #endif
74 
75 #ifdef LOGIN_CAP
76 #include <login_cap.h>
77 #endif
78 
79 #include "pathnames.h"
80 
81 /*
82  * Sleep times; used to prevent thrashing.
83  */
84 #define	GETTY_SPACING		 5	/* N secs minimum getty spacing */
85 #define	GETTY_SLEEP		30	/* sleep N secs after spacing problem */
86 #define GETTY_NSPACE             3      /* max. spacing count to bring reaction */
87 #define	WINDOW_WAIT		 3	/* wait N secs after starting window */
88 #define	STALL_TIMEOUT		30	/* wait N secs after warning */
89 #define	DEATH_WATCH		10	/* wait N secs for procs to die */
90 #define DEATH_SCRIPT		120	/* wait for 2min for /etc/rc.shutdown */
91 #define RESOURCE_RC		"daemon"
92 #define RESOURCE_WINDOW 	"default"
93 #define RESOURCE_GETTY		"default"
94 
95 void handle __P((sig_t, ...));
96 void delset __P((sigset_t *, ...));
97 
98 void stall __P((char *, ...));
99 void warning __P((char *, ...));
100 void emergency __P((char *, ...));
101 void disaster __P((int));
102 void badsys __P((int));
103 int  runshutdown __P((void));
104 
105 /*
106  * We really need a recursive typedef...
107  * The following at least guarantees that the return type of (*state_t)()
108  * is sufficiently wide to hold a function pointer.
109  */
110 typedef long (*state_func_t) __P((void));
111 typedef state_func_t (*state_t) __P((void));
112 
113 state_func_t single_user __P((void));
114 state_func_t runcom __P((void));
115 state_func_t read_ttys __P((void));
116 state_func_t multi_user __P((void));
117 state_func_t clean_ttys __P((void));
118 state_func_t catatonia __P((void));
119 state_func_t death __P((void));
120 
121 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
122 #define FALSE	0
123 #define TRUE	1
124 
125 int Reboot = FALSE;
126 int howto = RB_AUTOBOOT;
127 
128 void transition __P((state_t));
129 state_t requested_transition = runcom;
130 
131 void setctty __P((char *));
132 
133 typedef struct init_session {
134 	int	se_index;		/* index of entry in ttys file */
135 	pid_t	se_process;		/* controlling process */
136 	time_t	se_started;		/* used to avoid thrashing */
137 	int	se_flags;		/* status of session */
138 #define	SE_SHUTDOWN	0x1		/* session won't be restarted */
139 #define	SE_PRESENT	0x2		/* session is in /etc/ttys */
140 	int     se_nspace;              /* spacing count */
141 	char	*se_device;		/* filename of port */
142 	char	*se_getty;		/* what to run on that port */
143 	char    *se_getty_argv_space;   /* pre-parsed argument array space */
144 	char	**se_getty_argv;	/* pre-parsed argument array */
145 	char	*se_window;		/* window system (started only once) */
146 	char    *se_window_argv_space;  /* pre-parsed argument array space */
147 	char	**se_window_argv;	/* pre-parsed argument array */
148 	char    *se_type;               /* default terminal type */
149 	struct	init_session *se_prev;
150 	struct	init_session *se_next;
151 } session_t;
152 
153 void free_session __P((session_t *));
154 session_t *new_session __P((session_t *, int, struct ttyent *));
155 session_t *sessions;
156 
157 char **construct_argv __P((char *));
158 void start_window_system __P((session_t *));
159 void collect_child __P((pid_t));
160 pid_t start_getty __P((session_t *));
161 void transition_handler __P((int));
162 void alrm_handler __P((int));
163 void setsecuritylevel __P((int));
164 int getsecuritylevel __P((void));
165 int setupargv __P((session_t *, struct ttyent *));
166 #ifdef LOGIN_CAP
167 void setprocresources __P((const char *));
168 #endif
169 int clang;
170 
171 void clear_session_logs __P((session_t *));
172 
173 int start_session_db __P((void));
174 void add_session __P((session_t *));
175 void del_session __P((session_t *));
176 session_t *find_session __P((pid_t));
177 DB *session_db;
178 
179 /*
180  * The mother of all processes.
181  */
182 int
183 main(argc, argv)
184 	int argc;
185 	char **argv;
186 {
187 	int c;
188 	struct sigaction sa;
189 	sigset_t mask;
190 
191 
192 	/* Dispose of random users. */
193 	if (getuid() != 0)
194 		errx(1, "%s", strerror(EPERM));
195 
196 	/* System V users like to reexec init. */
197 	if (getpid() != 1) {
198 #ifdef COMPAT_SYSV_INIT
199 		/* So give them what they want */
200 		if (argc > 1) {
201 			if (strlen(argv[1]) == 1) {
202 				register char runlevel = *argv[1];
203 				register int sig;
204 
205 				switch (runlevel) {
206 					case '0': /* halt + poweroff */
207 						sig = SIGUSR2;
208 						break;
209 					case '1': /* single-user */
210 						sig = SIGTERM;
211 						break;
212 					case '6': /* reboot */
213 						sig = SIGINT;
214 						break;
215 					case 'c': /* block further logins */
216 						sig = SIGTSTP;
217 						break;
218 					case 'q': /* rescan /etc/ttys */
219 						sig = SIGHUP;
220 						break;
221 					default:
222 						goto invalid;
223 				}
224 				kill(1, sig);
225 				_exit(0);
226 			} else
227 invalid:
228 				errx(1, "invalid run-level ``%s''", argv[1]);
229 		} else
230 #endif
231 			errx(1, "already running");
232 	}
233 	/*
234 	 * Note that this does NOT open a file...
235 	 * Does 'init' deserve its own facility number?
236 	 */
237 	openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
238 
239 	/*
240 	 * Create an initial session.
241 	 */
242 	if (setsid() < 0)
243 		warning("initial setsid() failed: %m");
244 
245 	/*
246 	 * Establish an initial user so that programs running
247 	 * single user do not freak out and die (like passwd).
248 	 */
249 	if (setlogin("root") < 0)
250 		warning("setlogin() failed: %m");
251 
252 	/*
253 	 * This code assumes that we always get arguments through flags,
254 	 * never through bits set in some random machine register.
255 	 */
256 	while ((c = getopt(argc, argv, "dsf")) != -1)
257 		switch (c) {
258 		case 'd':
259 			/* We don't support DEVFS. */
260 			break;
261 		case 's':
262 			requested_transition = single_user;
263 			break;
264 		case 'f':
265 			runcom_mode = FASTBOOT;
266 			break;
267 		default:
268 			warning("unrecognized flag '-%c'", c);
269 			break;
270 		}
271 
272 	if (optind != argc)
273 		warning("ignoring excess arguments");
274 
275 	/*
276 	 * We catch or block signals rather than ignore them,
277 	 * so that they get reset on exec.
278 	 */
279 	handle(badsys, SIGSYS, 0);
280 	handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
281 	       SIGBUS, SIGXCPU, SIGXFSZ, 0);
282 	handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP,
283 		SIGUSR1, SIGUSR2, 0);
284 	handle(alrm_handler, SIGALRM, 0);
285 	sigfillset(&mask);
286 	delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
287 		SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
288 		SIGUSR1, SIGUSR2, 0);
289 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
290 	sigemptyset(&sa.sa_mask);
291 	sa.sa_flags = 0;
292 	sa.sa_handler = SIG_IGN;
293 	(void) sigaction(SIGTTIN, &sa, (struct sigaction *)0);
294 	(void) sigaction(SIGTTOU, &sa, (struct sigaction *)0);
295 
296 	/*
297 	 * Paranoia.
298 	 */
299 	close(0);
300 	close(1);
301 	close(2);
302 
303 	/*
304 	 * Start the state machine.
305 	 */
306 	transition(requested_transition);
307 
308 	/*
309 	 * Should never reach here.
310 	 */
311 	return 1;
312 }
313 
314 /*
315  * Associate a function with a signal handler.
316  */
317 void
318 #ifdef __STDC__
319 handle(sig_t handler, ...)
320 #else
321 handle(va_alist)
322 	va_dcl
323 #endif
324 {
325 	int sig;
326 	struct sigaction sa;
327 	sigset_t mask_everything;
328 	va_list ap;
329 #ifndef __STDC__
330 	sig_t handler;
331 
332 	va_start(ap);
333 	handler = va_arg(ap, sig_t);
334 #else
335 	va_start(ap, handler);
336 #endif
337 
338 	sa.sa_handler = handler;
339 	sigfillset(&mask_everything);
340 
341 	while ((sig = va_arg(ap, int)) != NULL) {
342 		sa.sa_mask = mask_everything;
343 		/* XXX SA_RESTART? */
344 		sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
345 		sigaction(sig, &sa, (struct sigaction *) 0);
346 	}
347 	va_end(ap);
348 }
349 
350 /*
351  * Delete a set of signals from a mask.
352  */
353 void
354 #ifdef __STDC__
355 delset(sigset_t *maskp, ...)
356 #else
357 delset(va_alist)
358 	va_dcl
359 #endif
360 {
361 	int sig;
362 	va_list ap;
363 #ifndef __STDC__
364 	sigset_t *maskp;
365 
366 	va_start(ap);
367 	maskp = va_arg(ap, sigset_t *);
368 #else
369 	va_start(ap, maskp);
370 #endif
371 
372 	while ((sig = va_arg(ap, int)) != NULL)
373 		sigdelset(maskp, sig);
374 	va_end(ap);
375 }
376 
377 /*
378  * Log a message and sleep for a while (to give someone an opportunity
379  * to read it and to save log or hardcopy output if the problem is chronic).
380  * NB: should send a message to the session logger to avoid blocking.
381  */
382 void
383 #ifdef __STDC__
384 stall(char *message, ...)
385 #else
386 stall(va_alist)
387 	va_dcl
388 #endif
389 {
390 	va_list ap;
391 #ifndef __STDC__
392 	char *message;
393 
394 	va_start(ap);
395 	message = va_arg(ap, char *);
396 #else
397 	va_start(ap, message);
398 #endif
399 
400 	vsyslog(LOG_ALERT, message, ap);
401 	va_end(ap);
402 	sleep(STALL_TIMEOUT);
403 }
404 
405 /*
406  * Like stall(), but doesn't sleep.
407  * If cpp had variadic macros, the two functions could be #defines for another.
408  * NB: should send a message to the session logger to avoid blocking.
409  */
410 void
411 #ifdef __STDC__
412 warning(char *message, ...)
413 #else
414 warning(va_alist)
415 	va_dcl
416 #endif
417 {
418 	va_list ap;
419 #ifndef __STDC__
420 	char *message;
421 
422 	va_start(ap);
423 	message = va_arg(ap, char *);
424 #else
425 	va_start(ap, message);
426 #endif
427 
428 	vsyslog(LOG_ALERT, message, ap);
429 	va_end(ap);
430 }
431 
432 /*
433  * Log an emergency message.
434  * NB: should send a message to the session logger to avoid blocking.
435  */
436 void
437 #ifdef __STDC__
438 emergency(char *message, ...)
439 #else
440 emergency(va_alist)
441 	va_dcl
442 #endif
443 {
444 	va_list ap;
445 #ifndef __STDC__
446 	char *message;
447 
448 	va_start(ap);
449 	message = va_arg(ap, char *);
450 #else
451 	va_start(ap, message);
452 #endif
453 
454 	vsyslog(LOG_EMERG, message, ap);
455 	va_end(ap);
456 }
457 
458 /*
459  * Catch a SIGSYS signal.
460  *
461  * These may arise if a system does not support sysctl.
462  * We tolerate up to 25 of these, then throw in the towel.
463  */
464 void
465 badsys(sig)
466 	int sig;
467 {
468 	static int badcount = 0;
469 
470 	if (badcount++ < 25)
471 		return;
472 	disaster(sig);
473 }
474 
475 /*
476  * Catch an unexpected signal.
477  */
478 void
479 disaster(sig)
480 	int sig;
481 {
482 	emergency("fatal signal: %s",
483 		(unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
484 
485 	sleep(STALL_TIMEOUT);
486 	_exit(sig);		/* reboot */
487 }
488 
489 /*
490  * Get the security level of the kernel.
491  */
492 int
493 getsecuritylevel()
494 {
495 #ifdef KERN_SECURELVL
496 	int name[2], curlevel;
497 	size_t len;
498 
499 	name[0] = CTL_KERN;
500 	name[1] = KERN_SECURELVL;
501 	len = sizeof curlevel;
502 	if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
503 		emergency("cannot get kernel security level: %s",
504 		    strerror(errno));
505 		return (-1);
506 	}
507 	return (curlevel);
508 #else
509 	return (-1);
510 #endif
511 }
512 
513 /*
514  * Set the security level of the kernel.
515  */
516 void
517 setsecuritylevel(newlevel)
518 	int newlevel;
519 {
520 #ifdef KERN_SECURELVL
521 	int name[2], curlevel;
522 
523 	curlevel = getsecuritylevel();
524 	if (newlevel == curlevel)
525 		return;
526 	name[0] = CTL_KERN;
527 	name[1] = KERN_SECURELVL;
528 	if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
529 		emergency(
530 		    "cannot change kernel security level from %d to %d: %s",
531 		    curlevel, newlevel, strerror(errno));
532 		return;
533 	}
534 #ifdef SECURE
535 	warning("kernel security level changed from %d to %d",
536 	    curlevel, newlevel);
537 #endif
538 #endif
539 }
540 
541 /*
542  * Change states in the finite state machine.
543  * The initial state is passed as an argument.
544  */
545 void
546 transition(s)
547 	state_t s;
548 {
549 	for (;;)
550 		s = (state_t) (*s)();
551 }
552 
553 /*
554  * Close out the accounting files for a login session.
555  * NB: should send a message to the session logger to avoid blocking.
556  */
557 void
558 clear_session_logs(sp)
559 	session_t *sp;
560 {
561 	char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
562 
563 	if (logout(line))
564 		logwtmp(line, "", "");
565 }
566 
567 /*
568  * Start a session and allocate a controlling terminal.
569  * Only called by children of init after forking.
570  */
571 void
572 setctty(name)
573 	char *name;
574 {
575 	int fd;
576 
577 	(void) revoke(name);
578 	if ((fd = open(name, O_RDWR)) == -1) {
579 		stall("can't open %s: %m", name);
580 		_exit(1);
581 	}
582 	if (login_tty(fd) == -1) {
583 		stall("can't get %s for controlling terminal: %m", name);
584 		_exit(1);
585 	}
586 }
587 
588 /*
589  * Bring the system up single user.
590  */
591 state_func_t
592 single_user()
593 {
594 	pid_t pid, wpid;
595 	int status;
596 	sigset_t mask;
597 	char *shell = _PATH_BSHELL;
598 	char *argv[2];
599 #ifdef SECURE
600 	struct ttyent *typ;
601 	struct passwd *pp;
602 	static const char banner[] =
603 		"Enter root password, or ^D to go multi-user\n";
604 	char *clear, *password;
605 #endif
606 #ifdef DEBUGSHELL
607 	char altshell[128];
608 #endif
609 
610 	if (Reboot) {
611 		/* Instead of going single user, let's reboot the machine */
612 		sync();
613 		alarm(2);
614 		pause();
615 		reboot(howto);
616 		_exit(0);
617 	}
618 
619 	if ((pid = fork()) == 0) {
620 		/*
621 		 * Start the single user session.
622 		 */
623 		setctty(_PATH_CONSOLE);
624 
625 #ifdef SECURE
626 		/*
627 		 * Check the root password.
628 		 * We don't care if the console is 'on' by default;
629 		 * it's the only tty that can be 'off' and 'secure'.
630 		 */
631 		typ = getttynam("console");
632 		pp = getpwnam("root");
633 		if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
634 		    pp && *pp->pw_passwd) {
635 			write(2, banner, sizeof banner - 1);
636 			for (;;) {
637 				clear = getpass("Password:");
638 				if (clear == 0 || *clear == '\0')
639 					_exit(0);
640 				password = crypt(clear, pp->pw_passwd);
641 				bzero(clear, _PASSWORD_LEN);
642 				if (strcmp(password, pp->pw_passwd) == 0)
643 					break;
644 				warning("single-user login failed\n");
645 			}
646 		}
647 		endttyent();
648 		endpwent();
649 #endif /* SECURE */
650 
651 #ifdef DEBUGSHELL
652 		{
653 			char *cp = altshell;
654 			int num;
655 
656 #define	SHREQUEST \
657 	"Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
658 			(void)write(STDERR_FILENO,
659 			    SHREQUEST, sizeof(SHREQUEST) - 1);
660 			while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
661 			    num != 0 && *cp != '\n' && cp < &altshell[127])
662 					cp++;
663 			*cp = '\0';
664 			if (altshell[0] != '\0')
665 				shell = altshell;
666 		}
667 #endif /* DEBUGSHELL */
668 
669 		/*
670 		 * Unblock signals.
671 		 * We catch all the interesting ones,
672 		 * and those are reset to SIG_DFL on exec.
673 		 */
674 		sigemptyset(&mask);
675 		sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
676 
677 		/*
678 		 * Fire off a shell.
679 		 * If the default one doesn't work, try the Bourne shell.
680 		 */
681 		argv[0] = "-sh";
682 		argv[1] = 0;
683 		execv(shell, argv);
684 		emergency("can't exec %s for single user: %m", shell);
685 		execv(_PATH_BSHELL, argv);
686 		emergency("can't exec %s for single user: %m", _PATH_BSHELL);
687 		sleep(STALL_TIMEOUT);
688 		_exit(1);
689 	}
690 
691 	if (pid == -1) {
692 		/*
693 		 * We are seriously hosed.  Do our best.
694 		 */
695 		emergency("can't fork single-user shell, trying again");
696 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
697 			continue;
698 		return (state_func_t) single_user;
699 	}
700 
701 	requested_transition = 0;
702 	do {
703 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
704 			collect_child(wpid);
705 		if (wpid == -1) {
706 			if (errno == EINTR)
707 				continue;
708 			warning("wait for single-user shell failed: %m; restarting");
709 			return (state_func_t) single_user;
710 		}
711 		if (wpid == pid && WIFSTOPPED(status)) {
712 			warning("init: shell stopped, restarting\n");
713 			kill(pid, SIGCONT);
714 			wpid = -1;
715 		}
716 	} while (wpid != pid && !requested_transition);
717 
718 	if (requested_transition)
719 		return (state_func_t) requested_transition;
720 
721 	if (!WIFEXITED(status)) {
722 		if (WTERMSIG(status) == SIGKILL) {
723 			/*
724 			 *  reboot(8) killed shell?
725 			 */
726 			warning("single user shell terminated.");
727 			sleep(STALL_TIMEOUT);
728 			_exit(0);
729 		} else {
730 			warning("single user shell terminated, restarting");
731 			return (state_func_t) single_user;
732 		}
733 	}
734 
735 	runcom_mode = FASTBOOT;
736 	return (state_func_t) runcom;
737 }
738 
739 /*
740  * Run the system startup script.
741  */
742 state_func_t
743 runcom()
744 {
745 	pid_t pid, wpid;
746 	int status;
747 	char *argv[4];
748 	struct sigaction sa;
749 
750 	if ((pid = fork()) == 0) {
751 		sigemptyset(&sa.sa_mask);
752 		sa.sa_flags = 0;
753 		sa.sa_handler = SIG_IGN;
754 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
755 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
756 
757 		setctty(_PATH_CONSOLE);
758 
759 		argv[0] = "sh";
760 		argv[1] = _PATH_RUNCOM;
761 		argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
762 		argv[3] = 0;
763 
764 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
765 
766 #ifdef LOGIN_CAP
767 		setprocresources(RESOURCE_RC);
768 #endif
769 		execv(_PATH_BSHELL, argv);
770 		stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
771 		_exit(1);	/* force single user mode */
772 	}
773 
774 	if (pid == -1) {
775 		emergency("can't fork for %s on %s: %m",
776 			_PATH_BSHELL, _PATH_RUNCOM);
777 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
778 			continue;
779 		sleep(STALL_TIMEOUT);
780 		return (state_func_t) single_user;
781 	}
782 
783 	/*
784 	 * Copied from single_user().  This is a bit paranoid.
785 	 */
786 	requested_transition = 0;
787 	do {
788 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
789 			collect_child(wpid);
790 		if (wpid == -1) {
791 			if (requested_transition == death)
792 				return (state_func_t) death;
793 			if (errno == EINTR)
794 				continue;
795 			warning("wait for %s on %s failed: %m; going to single user mode",
796 				_PATH_BSHELL, _PATH_RUNCOM);
797 			return (state_func_t) single_user;
798 		}
799 		if (wpid == pid && WIFSTOPPED(status)) {
800 			warning("init: %s on %s stopped, restarting\n",
801 				_PATH_BSHELL, _PATH_RUNCOM);
802 			kill(pid, SIGCONT);
803 			wpid = -1;
804 		}
805 	} while (wpid != pid);
806 
807 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
808 	    requested_transition == catatonia) {
809 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
810 		sigset_t s;
811 
812 		sigfillset(&s);
813 		for (;;)
814 			sigsuspend(&s);
815 	}
816 
817 	if (!WIFEXITED(status)) {
818 		warning("%s on %s terminated abnormally, going to single user mode",
819 			_PATH_BSHELL, _PATH_RUNCOM);
820 		return (state_func_t) single_user;
821 	}
822 
823 	if (WEXITSTATUS(status))
824 		return (state_func_t) single_user;
825 
826 	runcom_mode = AUTOBOOT;		/* the default */
827 	/* NB: should send a message to the session logger to avoid blocking. */
828 	logwtmp("~", "reboot", "");
829 	return (state_func_t) read_ttys;
830 }
831 
832 /*
833  * Open the session database.
834  *
835  * NB: We could pass in the size here; is it necessary?
836  */
837 int
838 start_session_db()
839 {
840 	if (session_db && (*session_db->close)(session_db))
841 		emergency("session database close: %s", strerror(errno));
842 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
843 		emergency("session database open: %s", strerror(errno));
844 		return (1);
845 	}
846 	return (0);
847 
848 }
849 
850 /*
851  * Add a new login session.
852  */
853 void
854 add_session(sp)
855 	session_t *sp;
856 {
857 	DBT key;
858 	DBT data;
859 
860 	key.data = &sp->se_process;
861 	key.size = sizeof sp->se_process;
862 	data.data = &sp;
863 	data.size = sizeof sp;
864 
865 	if ((*session_db->put)(session_db, &key, &data, 0))
866 		emergency("insert %d: %s", sp->se_process, strerror(errno));
867 }
868 
869 /*
870  * Delete an old login session.
871  */
872 void
873 del_session(sp)
874 	session_t *sp;
875 {
876 	DBT key;
877 
878 	key.data = &sp->se_process;
879 	key.size = sizeof sp->se_process;
880 
881 	if ((*session_db->del)(session_db, &key, 0))
882 		emergency("delete %d: %s", sp->se_process, strerror(errno));
883 }
884 
885 /*
886  * Look up a login session by pid.
887  */
888 session_t *
889 #ifdef __STDC__
890 find_session(pid_t pid)
891 #else
892 find_session(pid)
893 	pid_t pid;
894 #endif
895 {
896 	DBT key;
897 	DBT data;
898 	session_t *ret;
899 
900 	key.data = &pid;
901 	key.size = sizeof pid;
902 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
903 		return 0;
904 	bcopy(data.data, (char *)&ret, sizeof(ret));
905 	return ret;
906 }
907 
908 /*
909  * Construct an argument vector from a command line.
910  */
911 char **
912 construct_argv(command)
913 	char *command;
914 {
915 	char *strk (char *);
916 	register int argc = 0;
917 	register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
918 						* sizeof (char *));
919 
920 	if ((argv[argc++] = strk(command)) == 0) {
921 		free(argv);
922 		return (NULL);
923 	}
924 	while ((argv[argc++] = strk((char *) 0)) != NULL)
925 		continue;
926 	return argv;
927 }
928 
929 /*
930  * Deallocate a session descriptor.
931  */
932 void
933 free_session(sp)
934 	register session_t *sp;
935 {
936 	free(sp->se_device);
937 	if (sp->se_getty) {
938 		free(sp->se_getty);
939 		free(sp->se_getty_argv_space);
940 		free(sp->se_getty_argv);
941 	}
942 	if (sp->se_window) {
943 		free(sp->se_window);
944 		free(sp->se_window_argv_space);
945 		free(sp->se_window_argv);
946 	}
947 	if (sp->se_type)
948 		free(sp->se_type);
949 	free(sp);
950 }
951 
952 /*
953  * Allocate a new session descriptor.
954  * Mark it SE_PRESENT.
955  */
956 session_t *
957 new_session(sprev, session_index, typ)
958 	session_t *sprev;
959 	int session_index;
960 	register struct ttyent *typ;
961 {
962 	register session_t *sp;
963 	int fd;
964 
965 	if ((typ->ty_status & TTY_ON) == 0 ||
966 	    typ->ty_name == 0 ||
967 	    typ->ty_getty == 0)
968 		return 0;
969 
970 	sp = (session_t *) calloc(1, sizeof (session_t));
971 
972 	sp->se_index = session_index;
973 	sp->se_flags |= SE_PRESENT;
974 
975 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
976 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
977 
978 	/*
979 	 * Attempt to open the device, if we get "device not configured"
980 	 * then don't add the device to the session list.
981 	 */
982 	if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
983 		if (errno == ENXIO) {
984 			free_session(sp);
985 			return (0);
986 		}
987 	} else
988 		close(fd);
989 
990 	if (setupargv(sp, typ) == 0) {
991 		free_session(sp);
992 		return (0);
993 	}
994 
995 	sp->se_next = 0;
996 	if (sprev == 0) {
997 		sessions = sp;
998 		sp->se_prev = 0;
999 	} else {
1000 		sprev->se_next = sp;
1001 		sp->se_prev = sprev;
1002 	}
1003 
1004 	return sp;
1005 }
1006 
1007 /*
1008  * Calculate getty and if useful window argv vectors.
1009  */
1010 int
1011 setupargv(sp, typ)
1012 	session_t *sp;
1013 	struct ttyent *typ;
1014 {
1015 
1016 	if (sp->se_getty) {
1017 		free(sp->se_getty);
1018 		free(sp->se_getty_argv_space);
1019 		free(sp->se_getty_argv);
1020 	}
1021 	sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1022 	(void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1023 	sp->se_getty_argv_space = strdup(sp->se_getty);
1024 	sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1025 	if (sp->se_getty_argv == 0) {
1026 		warning("can't parse getty for port %s", sp->se_device);
1027 		free(sp->se_getty);
1028 		free(sp->se_getty_argv_space);
1029 		sp->se_getty = sp->se_getty_argv_space = 0;
1030 		return (0);
1031 	}
1032 	if (sp->se_window) {
1033 		free(sp->se_window);
1034 		free(sp->se_window_argv_space);
1035 		free(sp->se_window_argv);
1036 	}
1037 	sp->se_window = sp->se_window_argv_space = 0;
1038 	sp->se_window_argv = 0;
1039 	if (typ->ty_window) {
1040 		sp->se_window = strdup(typ->ty_window);
1041 		sp->se_window_argv_space = strdup(sp->se_window);
1042 		sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1043 		if (sp->se_window_argv == 0) {
1044 			warning("can't parse window for port %s",
1045 				sp->se_device);
1046 			free(sp->se_window_argv_space);
1047 			free(sp->se_window);
1048 			sp->se_window = sp->se_window_argv_space = 0;
1049 			return (0);
1050 		}
1051 	}
1052 	if (sp->se_type)
1053 		free(sp->se_type);
1054 	sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1055 	return (1);
1056 }
1057 
1058 /*
1059  * Walk the list of ttys and create sessions for each active line.
1060  */
1061 state_func_t
1062 read_ttys()
1063 {
1064 	int session_index = 0;
1065 	register session_t *sp, *snext;
1066 	register struct ttyent *typ;
1067 
1068 	/*
1069 	 * Destroy any previous session state.
1070 	 * There shouldn't be any, but just in case...
1071 	 */
1072 	for (sp = sessions; sp; sp = snext) {
1073 		if (sp->se_process)
1074 			clear_session_logs(sp);
1075 		snext = sp->se_next;
1076 		free_session(sp);
1077 	}
1078 	sessions = 0;
1079 	if (start_session_db())
1080 		return (state_func_t) single_user;
1081 
1082 	/*
1083 	 * Allocate a session entry for each active port.
1084 	 * Note that sp starts at 0.
1085 	 */
1086 	while ((typ = getttyent()) != NULL)
1087 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1088 			sp = snext;
1089 
1090 	endttyent();
1091 
1092 	return (state_func_t) multi_user;
1093 }
1094 
1095 /*
1096  * Start a window system running.
1097  */
1098 void
1099 start_window_system(sp)
1100 	session_t *sp;
1101 {
1102 	pid_t pid;
1103 	sigset_t mask;
1104 	char term[64], *env[2];
1105 
1106 	if ((pid = fork()) == -1) {
1107 		emergency("can't fork for window system on port %s: %m",
1108 			sp->se_device);
1109 		/* hope that getty fails and we can try again */
1110 		return;
1111 	}
1112 
1113 	if (pid)
1114 		return;
1115 
1116 	sigemptyset(&mask);
1117 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1118 
1119 	if (setsid() < 0)
1120 		emergency("setsid failed (window) %m");
1121 
1122 #ifdef LOGIN_CAP
1123 	setprocresources(RESOURCE_WINDOW);
1124 #endif
1125 	if (sp->se_type) {
1126 		/* Don't use malloc after fork */
1127 		strcpy(term, "TERM=");
1128 		strncat(term, sp->se_type, sizeof(term) - 6);
1129 		env[0] = term;
1130 		env[1] = 0;
1131 	}
1132 	else
1133 		env[0] = 0;
1134 	execve(sp->se_window_argv[0], sp->se_window_argv, env);
1135 	stall("can't exec window system '%s' for port %s: %m",
1136 		sp->se_window_argv[0], sp->se_device);
1137 	_exit(1);
1138 }
1139 
1140 /*
1141  * Start a login session running.
1142  */
1143 pid_t
1144 start_getty(sp)
1145 	session_t *sp;
1146 {
1147 	pid_t pid;
1148 	sigset_t mask;
1149 	time_t current_time = time((time_t *) 0);
1150 	int too_quick = 0;
1151 	char term[64], *env[2];
1152 
1153 	if (current_time >= sp->se_started &&
1154 	    current_time - sp->se_started < GETTY_SPACING) {
1155 		if (++sp->se_nspace > GETTY_NSPACE) {
1156 			sp->se_nspace = 0;
1157 			too_quick = 1;
1158 		}
1159 	} else
1160 		sp->se_nspace = 0;
1161 
1162 	/*
1163 	 * fork(), not vfork() -- we can't afford to block.
1164 	 */
1165 	if ((pid = fork()) == -1) {
1166 		emergency("can't fork for getty on port %s: %m", sp->se_device);
1167 		return -1;
1168 	}
1169 
1170 	if (pid)
1171 		return pid;
1172 
1173 	if (too_quick) {
1174 		warning("getty repeating too quickly on port %s, sleeping %d secs",
1175 			sp->se_device, GETTY_SLEEP);
1176 		sleep((unsigned) GETTY_SLEEP);
1177 	}
1178 
1179 	if (sp->se_window) {
1180 		start_window_system(sp);
1181 		sleep(WINDOW_WAIT);
1182 	}
1183 
1184 	sigemptyset(&mask);
1185 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1186 
1187 #ifdef LOGIN_CAP
1188 	setprocresources(RESOURCE_GETTY);
1189 #endif
1190 	if (sp->se_type) {
1191 		/* Don't use malloc after fork */
1192 		strcpy(term, "TERM=");
1193 		strncat(term, sp->se_type, sizeof(term) - 6);
1194 		env[0] = term;
1195 		env[1] = 0;
1196 	}
1197 	else
1198 		env[0] = 0;
1199 	execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1200 	stall("can't exec getty '%s' for port %s: %m",
1201 		sp->se_getty_argv[0], sp->se_device);
1202 	_exit(1);
1203 }
1204 
1205 /*
1206  * Collect exit status for a child.
1207  * If an exiting login, start a new login running.
1208  */
1209 void
1210 #ifdef __STDC__
1211 collect_child(pid_t pid)
1212 #else
1213 collect_child(pid)
1214 	pid_t pid;
1215 #endif
1216 {
1217 	register session_t *sp, *sprev, *snext;
1218 
1219 	if (! sessions)
1220 		return;
1221 
1222 	if (! (sp = find_session(pid)))
1223 		return;
1224 
1225 	clear_session_logs(sp);
1226 	del_session(sp);
1227 	sp->se_process = 0;
1228 
1229 	if (sp->se_flags & SE_SHUTDOWN) {
1230 		if ((sprev = sp->se_prev) != NULL)
1231 			sprev->se_next = sp->se_next;
1232 		else
1233 			sessions = sp->se_next;
1234 		if ((snext = sp->se_next) != NULL)
1235 			snext->se_prev = sp->se_prev;
1236 		free_session(sp);
1237 		return;
1238 	}
1239 
1240 	if ((pid = start_getty(sp)) == -1) {
1241 		/* serious trouble */
1242 		requested_transition = clean_ttys;
1243 		return;
1244 	}
1245 
1246 	sp->se_process = pid;
1247 	sp->se_started = time((time_t *) 0);
1248 	add_session(sp);
1249 }
1250 
1251 /*
1252  * Catch a signal and request a state transition.
1253  */
1254 void
1255 transition_handler(sig)
1256 	int sig;
1257 {
1258 
1259 	switch (sig) {
1260 	case SIGHUP:
1261 		requested_transition = clean_ttys;
1262 		break;
1263 	case SIGUSR2:
1264 		howto = RB_POWEROFF;
1265 	case SIGUSR1:
1266 		howto |= RB_HALT;
1267 	case SIGINT:
1268 		Reboot = TRUE;
1269 	case SIGTERM:
1270 		requested_transition = death;
1271 		break;
1272 	case SIGTSTP:
1273 		requested_transition = catatonia;
1274 		break;
1275 	default:
1276 		requested_transition = 0;
1277 		break;
1278 	}
1279 }
1280 
1281 /*
1282  * Take the system multiuser.
1283  */
1284 state_func_t
1285 multi_user()
1286 {
1287 	pid_t pid;
1288 	register session_t *sp;
1289 
1290 	requested_transition = 0;
1291 
1292 	/*
1293 	 * If the administrator has not set the security level to -1
1294 	 * to indicate that the kernel should not run multiuser in secure
1295 	 * mode, and the run script has not set a higher level of security
1296 	 * than level 1, then put the kernel into secure mode.
1297 	 */
1298 	if (getsecuritylevel() == 0)
1299 		setsecuritylevel(1);
1300 
1301 	for (sp = sessions; sp; sp = sp->se_next) {
1302 		if (sp->se_process)
1303 			continue;
1304 		if ((pid = start_getty(sp)) == -1) {
1305 			/* serious trouble */
1306 			requested_transition = clean_ttys;
1307 			break;
1308 		}
1309 		sp->se_process = pid;
1310 		sp->se_started = time((time_t *) 0);
1311 		add_session(sp);
1312 	}
1313 
1314 	while (!requested_transition)
1315 		if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1316 			collect_child(pid);
1317 
1318 	return (state_func_t) requested_transition;
1319 }
1320 
1321 /*
1322  * This is an (n*2)+(n^2) algorithm.  We hope it isn't run often...
1323  */
1324 state_func_t
1325 clean_ttys()
1326 {
1327 	register session_t *sp, *sprev;
1328 	register struct ttyent *typ;
1329 	register int session_index = 0;
1330 	register int devlen;
1331 	char *old_getty, *old_window, *old_type;
1332 
1333 	if (! sessions)
1334 		return (state_func_t) multi_user;
1335 
1336 	/*
1337 	 * mark all sessions for death, (!SE_PRESENT)
1338 	 * as we find or create new ones they'll be marked as keepers,
1339 	 * we'll later nuke all the ones not found in /etc/ttys
1340 	 */
1341 	for (sp = sessions; sp != NULL; sp = sp->se_next)
1342 		sp->se_flags &= ~SE_PRESENT;
1343 
1344 	devlen = sizeof(_PATH_DEV) - 1;
1345 	while ((typ = getttyent()) != NULL) {
1346 		++session_index;
1347 
1348 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1349 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1350 				break;
1351 
1352 		if (sp) {
1353 			/* we want this one to live */
1354 			sp->se_flags |= SE_PRESENT;
1355 			if (sp->se_index != session_index) {
1356 				warning("port %s changed utmp index from %d to %d",
1357 				       sp->se_device, sp->se_index,
1358 				       session_index);
1359 				sp->se_index = session_index;
1360 			}
1361 			if ((typ->ty_status & TTY_ON) == 0 ||
1362 			    typ->ty_getty == 0) {
1363 				sp->se_flags |= SE_SHUTDOWN;
1364 				kill(sp->se_process, SIGHUP);
1365 				continue;
1366 			}
1367 			sp->se_flags &= ~SE_SHUTDOWN;
1368 			old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1369 			old_window = sp->se_window ? strdup(sp->se_window) : 0;
1370 			old_type = sp->se_type ? strdup(sp->se_type) : 0;
1371 			if (setupargv(sp, typ) == 0) {
1372 				warning("can't parse getty for port %s",
1373 					sp->se_device);
1374 				sp->se_flags |= SE_SHUTDOWN;
1375 				kill(sp->se_process, SIGHUP);
1376 			}
1377 			else if (   !old_getty
1378 				 || (!old_type && sp->se_type)
1379 				 || (old_type && !sp->se_type)
1380 				 || (!old_window && sp->se_window)
1381 				 || (old_window && !sp->se_window)
1382 				 || (strcmp(old_getty, sp->se_getty) != 0)
1383 				 || (old_window && strcmp(old_window, sp->se_window) != 0)
1384 				 || (old_type && strcmp(old_type, sp->se_type) != 0)
1385 				) {
1386 				/* Don't set SE_SHUTDOWN here */
1387 				sp->se_nspace = 0;
1388 				sp->se_started = 0;
1389 				kill(sp->se_process, SIGHUP);
1390 			}
1391 			if (old_getty)
1392 				free(old_getty);
1393 			if (old_window)
1394 				free(old_window);
1395 			if (old_type)
1396 				free(old_type);
1397 			continue;
1398 		}
1399 
1400 		new_session(sprev, session_index, typ);
1401 	}
1402 
1403 	endttyent();
1404 
1405 	/*
1406 	 * sweep through and kill all deleted sessions
1407 	 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1408 	 */
1409 	for (sp = sessions; sp != NULL; sp = sp->se_next) {
1410 		if ((sp->se_flags & SE_PRESENT) == 0) {
1411 			sp->se_flags |= SE_SHUTDOWN;
1412 			kill(sp->se_process, SIGHUP);
1413 		}
1414 	}
1415 
1416 	return (state_func_t) multi_user;
1417 }
1418 
1419 /*
1420  * Block further logins.
1421  */
1422 state_func_t
1423 catatonia()
1424 {
1425 	register session_t *sp;
1426 
1427 	for (sp = sessions; sp; sp = sp->se_next)
1428 		sp->se_flags |= SE_SHUTDOWN;
1429 
1430 	return (state_func_t) multi_user;
1431 }
1432 
1433 /*
1434  * Note SIGALRM.
1435  */
1436 void
1437 alrm_handler(sig)
1438 	int sig;
1439 {
1440 	(void)sig;
1441 	clang = 1;
1442 }
1443 
1444 /*
1445  * Bring the system down to single user.
1446  */
1447 state_func_t
1448 death()
1449 {
1450 	register session_t *sp;
1451 	register int i;
1452 	pid_t pid;
1453 	static const int death_sigs[2] = { SIGTERM, SIGKILL };
1454 
1455 	/* NB: should send a message to the session logger to avoid blocking. */
1456 	logwtmp("~", "shutdown", "");
1457 
1458 	for (sp = sessions; sp; sp = sp->se_next) {
1459 		sp->se_flags |= SE_SHUTDOWN;
1460 		kill(sp->se_process, SIGHUP);
1461 	}
1462 
1463 	/* Try to run the rc.shutdown script within a period of time */
1464 	(void) runshutdown();
1465 
1466 	for (i = 0; i < 2; ++i) {
1467 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1468 			return (state_func_t) single_user;
1469 
1470 		clang = 0;
1471 		alarm(DEATH_WATCH);
1472 		do
1473 			if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1474 				collect_child(pid);
1475 		while (clang == 0 && errno != ECHILD);
1476 
1477 		if (errno == ECHILD)
1478 			return (state_func_t) single_user;
1479 	}
1480 
1481 	warning("some processes would not die; ps axl advised");
1482 
1483 	return (state_func_t) single_user;
1484 }
1485 
1486 /*
1487  * Run the system shutdown script.
1488  *
1489  * Exit codes:      XXX I should document more
1490  * -2       shutdown script terminated abnormally
1491  * -1       fatal error - can't run script
1492  * 0        good.
1493  * >0       some error (exit code)
1494  */
1495 int
1496 runshutdown()
1497 {
1498 	pid_t pid, wpid;
1499 	int status;
1500 	int shutdowntimeout;
1501 	size_t len;
1502 	char *argv[4];
1503 	struct sigaction sa;
1504 	struct stat sb;
1505 
1506 	/*
1507 	 * rc.shutdown is optional, so to prevent any unnecessary
1508 	 * complaints from the shell we simply don't run it if the
1509 	 * file does not exist. If the stat() here fails for other
1510 	 * reasons, we'll let the shell complain.
1511 	 */
1512 	if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1513 		return 0;
1514 
1515 	if ((pid = fork()) == 0) {
1516 		int	fd;
1517 
1518 		/* Assume that init already grab console as ctty before */
1519 
1520 		sigemptyset(&sa.sa_mask);
1521 		sa.sa_flags = 0;
1522 		sa.sa_handler = SIG_IGN;
1523 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1524 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
1525 
1526 		if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1527 		    warning("can't open %s: %m", _PATH_CONSOLE);
1528 		else {
1529 		    (void) dup2(fd, 0);
1530 		    (void) dup2(fd, 1);
1531 		    (void) dup2(fd, 2);
1532 		    if (fd > 2)
1533 			close(fd);
1534 		}
1535 
1536 		/*
1537 		 * Run the shutdown script.
1538 		 */
1539 		argv[0] = "sh";
1540 		argv[1] = _PATH_RUNDOWN;
1541 		if (Reboot)
1542 			argv[2] = "reboot";
1543 		else
1544 			argv[2] = "single";
1545 		argv[3] = 0;
1546 
1547 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1548 
1549 #ifdef LOGIN_CAP
1550 		setprocresources(RESOURCE_RC);
1551 #endif
1552 		execv(_PATH_BSHELL, argv);
1553 		warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1554 		_exit(1);	/* force single user mode */
1555 	}
1556 
1557 	if (pid == -1) {
1558 		emergency("can't fork for %s on %s: %m",
1559 			_PATH_BSHELL, _PATH_RUNDOWN);
1560 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1561 			continue;
1562 		sleep(STALL_TIMEOUT);
1563 		return -1;
1564 	}
1565 
1566 	len = sizeof(shutdowntimeout);
1567 	if (sysctlbyname("kern.shutdown_timeout",
1568 			 &shutdowntimeout,
1569 			 &len, NULL, 0) == -1 || shutdowntimeout < 2)
1570 	    shutdowntimeout = DEATH_SCRIPT;
1571 	alarm(shutdowntimeout);
1572 	clang = 0;
1573 	/*
1574 	 * Copied from single_user().  This is a bit paranoid.
1575 	 * Use the same ALRM handler.
1576 	 */
1577 	do {
1578 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1579 			collect_child(wpid);
1580 		if (clang == 1) {
1581 			/* we were waiting for the sub-shell */
1582 			kill(wpid, SIGTERM);
1583 			warning("timeout expired for %s on %s: %m; going to single user mode",
1584 				_PATH_BSHELL, _PATH_RUNDOWN);
1585 			return -1;
1586 		}
1587 		if (wpid == -1) {
1588 			if (errno == EINTR)
1589 				continue;
1590 			warning("wait for %s on %s failed: %m; going to single user mode",
1591 				_PATH_BSHELL, _PATH_RUNDOWN);
1592 			return -1;
1593 		}
1594 		if (wpid == pid && WIFSTOPPED(status)) {
1595 			warning("init: %s on %s stopped, restarting\n",
1596 				_PATH_BSHELL, _PATH_RUNDOWN);
1597 			kill(pid, SIGCONT);
1598 			wpid = -1;
1599 		}
1600 	} while (wpid != pid && !clang);
1601 
1602 	/* Turn off the alarm */
1603 	alarm(0);
1604 
1605 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1606 	    requested_transition == catatonia) {
1607 		/*
1608 		 * /etc/rc.shutdown executed /sbin/reboot;
1609 		 * wait for the end quietly
1610 		 */
1611 		sigset_t s;
1612 
1613 		sigfillset(&s);
1614 		for (;;)
1615 			sigsuspend(&s);
1616 	}
1617 
1618 	if (!WIFEXITED(status)) {
1619 		warning("%s on %s terminated abnormally, going to single user mode",
1620 			_PATH_BSHELL, _PATH_RUNDOWN);
1621 		return -2;
1622 	}
1623 
1624 	if ((status = WEXITSTATUS(status)) != 0)
1625 		warning("%s returned status %d", _PATH_RUNDOWN, status);
1626 
1627 	return status;
1628 }
1629 
1630 char *
1631 strk (char *p)
1632 {
1633     static char *t;
1634     char *q;
1635     int c;
1636 
1637     if (p)
1638 	t = p;
1639     if (!t)
1640 	return 0;
1641 
1642     c = *t;
1643     while (c == ' ' || c == '\t' )
1644 	c = *++t;
1645     if (!c) {
1646 	t = 0;
1647 	return 0;
1648     }
1649     q = t;
1650     if (c == '\'') {
1651 	c = *++t;
1652 	q = t;
1653 	while (c && c != '\'')
1654 	    c = *++t;
1655 	if (!c)  /* unterminated string */
1656 	    q = t = 0;
1657 	else
1658 	    *t++ = 0;
1659     } else {
1660 	while (c && c != ' ' && c != '\t' )
1661 	    c = *++t;
1662 	*t++ = 0;
1663 	if (!c)
1664 	    t = 0;
1665     }
1666     return q;
1667 }
1668 
1669 #ifdef LOGIN_CAP
1670 void
1671 setprocresources(cname)
1672 	const char *cname;
1673 {
1674 	login_cap_t *lc;
1675 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1676 		setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1677 		login_close(lc);
1678 	}
1679 }
1680 #endif
1681