xref: /freebsd/sbin/init/init.c (revision 5129159789cc9d7bc514e4546b88e3427695002d)
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 	if (Reboot) {
627 		/* Instead of going single user, let's reboot the machine */
628 		sync();
629 		alarm(2);
630 		pause();
631 		reboot(howto);
632 		_exit(0);
633 	}
634 
635 	if ((pid = fork()) == 0) {
636 		/*
637 		 * Start the single user session.
638 		 */
639 		setctty(_PATH_CONSOLE);
640 
641 #ifdef SECURE
642 		/*
643 		 * Check the root password.
644 		 * We don't care if the console is 'on' by default;
645 		 * it's the only tty that can be 'off' and 'secure'.
646 		 */
647 		typ = getttynam("console");
648 		pp = getpwnam("root");
649 		if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
650 		    pp && *pp->pw_passwd) {
651 			write(2, banner, sizeof banner - 1);
652 			for (;;) {
653 				clear = getpass("Password:");
654 				if (clear == 0 || *clear == '\0')
655 					_exit(0);
656 				password = crypt(clear, pp->pw_passwd);
657 				bzero(clear, _PASSWORD_LEN);
658 				if (strcmp(password, pp->pw_passwd) == 0)
659 					break;
660 				warning("single-user login failed\n");
661 			}
662 		}
663 		endttyent();
664 		endpwent();
665 #endif /* SECURE */
666 
667 #ifdef DEBUGSHELL
668 		{
669 			char *cp = altshell;
670 			int num;
671 
672 #define	SHREQUEST \
673 	"Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
674 			(void)write(STDERR_FILENO,
675 			    SHREQUEST, sizeof(SHREQUEST) - 1);
676 			while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
677 			    num != 0 && *cp != '\n' && cp < &altshell[127])
678 					cp++;
679 			*cp = '\0';
680 			if (altshell[0] != '\0')
681 				shell = altshell;
682 		}
683 #endif /* DEBUGSHELL */
684 
685 		/*
686 		 * Unblock signals.
687 		 * We catch all the interesting ones,
688 		 * and those are reset to SIG_DFL on exec.
689 		 */
690 		sigemptyset(&mask);
691 		sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
692 
693 		/*
694 		 * Fire off a shell.
695 		 * If the default one doesn't work, try the Bourne shell.
696 		 */
697 		argv[0] = "-sh";
698 		argv[1] = 0;
699 		execv(shell, argv);
700 		emergency("can't exec %s for single user: %m", shell);
701 		execv(_PATH_BSHELL, argv);
702 		emergency("can't exec %s for single user: %m", _PATH_BSHELL);
703 		sleep(STALL_TIMEOUT);
704 		_exit(1);
705 	}
706 
707 	if (pid == -1) {
708 		/*
709 		 * We are seriously hosed.  Do our best.
710 		 */
711 		emergency("can't fork single-user shell, trying again");
712 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
713 			continue;
714 		return (state_func_t) single_user;
715 	}
716 
717 	requested_transition = 0;
718 	do {
719 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
720 			collect_child(wpid);
721 		if (wpid == -1) {
722 			if (errno == EINTR)
723 				continue;
724 			warning("wait for single-user shell failed: %m; restarting");
725 			return (state_func_t) single_user;
726 		}
727 		if (wpid == pid && WIFSTOPPED(status)) {
728 			warning("init: shell stopped, restarting\n");
729 			kill(pid, SIGCONT);
730 			wpid = -1;
731 		}
732 	} while (wpid != pid && !requested_transition);
733 
734 	if (requested_transition)
735 		return (state_func_t) requested_transition;
736 
737 	if (!WIFEXITED(status)) {
738 		if (WTERMSIG(status) == SIGKILL) {
739 			/*
740 			 *  reboot(8) killed shell?
741 			 */
742 			warning("single user shell terminated.");
743 			sleep(STALL_TIMEOUT);
744 			_exit(0);
745 		} else {
746 			warning("single user shell terminated, restarting");
747 			return (state_func_t) single_user;
748 		}
749 	}
750 
751 	runcom_mode = FASTBOOT;
752 	return (state_func_t) runcom;
753 }
754 
755 /*
756  * Run the system startup script.
757  */
758 state_func_t
759 runcom()
760 {
761 	pid_t pid, wpid;
762 	int status;
763 	char *argv[4];
764 	struct sigaction sa;
765 
766 	if ((pid = fork()) == 0) {
767 		sigemptyset(&sa.sa_mask);
768 		sa.sa_flags = 0;
769 		sa.sa_handler = SIG_IGN;
770 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
771 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
772 
773 		setctty(_PATH_CONSOLE);
774 
775 		argv[0] = "sh";
776 		argv[1] = _PATH_RUNCOM;
777 		argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
778 		argv[3] = 0;
779 
780 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
781 
782 #ifdef LOGIN_CAP
783 		setprocresources(RESOURCE_RC);
784 #endif
785 		execv(_PATH_BSHELL, argv);
786 		stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
787 		_exit(1);	/* force single user mode */
788 	}
789 
790 	if (pid == -1) {
791 		emergency("can't fork for %s on %s: %m",
792 			_PATH_BSHELL, _PATH_RUNCOM);
793 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
794 			continue;
795 		sleep(STALL_TIMEOUT);
796 		return (state_func_t) single_user;
797 	}
798 
799 	/*
800 	 * Copied from single_user().  This is a bit paranoid.
801 	 */
802 	do {
803 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
804 			collect_child(wpid);
805 		if (wpid == -1) {
806 			if (errno == EINTR)
807 				continue;
808 			warning("wait for %s on %s failed: %m; going to single user mode",
809 				_PATH_BSHELL, _PATH_RUNCOM);
810 			return (state_func_t) single_user;
811 		}
812 		if (wpid == pid && WIFSTOPPED(status)) {
813 			warning("init: %s on %s stopped, restarting\n",
814 				_PATH_BSHELL, _PATH_RUNCOM);
815 			kill(pid, SIGCONT);
816 			wpid = -1;
817 		}
818 	} while (wpid != pid);
819 
820 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
821 	    requested_transition == catatonia) {
822 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
823 		sigset_t s;
824 
825 		sigfillset(&s);
826 		for (;;)
827 			sigsuspend(&s);
828 	}
829 
830 	if (!WIFEXITED(status)) {
831 		warning("%s on %s terminated abnormally, going to single user mode",
832 			_PATH_BSHELL, _PATH_RUNCOM);
833 		return (state_func_t) single_user;
834 	}
835 
836 	if (WEXITSTATUS(status))
837 		return (state_func_t) single_user;
838 
839 	runcom_mode = AUTOBOOT;		/* the default */
840 	/* NB: should send a message to the session logger to avoid blocking. */
841 	logwtmp("~", "reboot", "");
842 	return (state_func_t) read_ttys;
843 }
844 
845 /*
846  * Open the session database.
847  *
848  * NB: We could pass in the size here; is it necessary?
849  */
850 int
851 start_session_db()
852 {
853 	if (session_db && (*session_db->close)(session_db))
854 		emergency("session database close: %s", strerror(errno));
855 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
856 		emergency("session database open: %s", strerror(errno));
857 		return (1);
858 	}
859 	return (0);
860 
861 }
862 
863 /*
864  * Add a new login session.
865  */
866 void
867 add_session(sp)
868 	session_t *sp;
869 {
870 	DBT key;
871 	DBT data;
872 
873 	key.data = &sp->se_process;
874 	key.size = sizeof sp->se_process;
875 	data.data = &sp;
876 	data.size = sizeof sp;
877 
878 	if ((*session_db->put)(session_db, &key, &data, 0))
879 		emergency("insert %d: %s", sp->se_process, strerror(errno));
880 }
881 
882 /*
883  * Delete an old login session.
884  */
885 void
886 del_session(sp)
887 	session_t *sp;
888 {
889 	DBT key;
890 
891 	key.data = &sp->se_process;
892 	key.size = sizeof sp->se_process;
893 
894 	if ((*session_db->del)(session_db, &key, 0))
895 		emergency("delete %d: %s", sp->se_process, strerror(errno));
896 }
897 
898 /*
899  * Look up a login session by pid.
900  */
901 session_t *
902 #ifdef __STDC__
903 find_session(pid_t pid)
904 #else
905 find_session(pid)
906 	pid_t pid;
907 #endif
908 {
909 	DBT key;
910 	DBT data;
911 	session_t *ret;
912 
913 	key.data = &pid;
914 	key.size = sizeof pid;
915 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
916 		return 0;
917 	bcopy(data.data, (char *)&ret, sizeof(ret));
918 	return ret;
919 }
920 
921 /*
922  * Construct an argument vector from a command line.
923  */
924 char **
925 construct_argv(command)
926 	char *command;
927 {
928 	char *strk (char *);
929 	register int argc = 0;
930 	register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
931 						* sizeof (char *));
932 
933 	if ((argv[argc++] = strk(command)) == 0) {
934 		free(argv);
935 		return (NULL);
936 	}
937 	while ((argv[argc++] = strk((char *) 0)) != NULL)
938 		continue;
939 	return argv;
940 }
941 
942 /*
943  * Deallocate a session descriptor.
944  */
945 void
946 free_session(sp)
947 	register session_t *sp;
948 {
949 	free(sp->se_device);
950 	if (sp->se_getty) {
951 		free(sp->se_getty);
952 		free(sp->se_getty_argv_space);
953 		free(sp->se_getty_argv);
954 	}
955 	if (sp->se_window) {
956 		free(sp->se_window);
957 		free(sp->se_window_argv_space);
958 		free(sp->se_window_argv);
959 	}
960 	if (sp->se_type)
961 		free(sp->se_type);
962 	free(sp);
963 }
964 
965 /*
966  * Allocate a new session descriptor.
967  */
968 session_t *
969 new_session(sprev, session_index, typ)
970 	session_t *sprev;
971 	int session_index;
972 	register struct ttyent *typ;
973 {
974 	register session_t *sp;
975 	int fd;
976 
977 	if ((typ->ty_status & TTY_ON) == 0 ||
978 	    typ->ty_name == 0 ||
979 	    typ->ty_getty == 0)
980 		return 0;
981 
982 	sp = (session_t *) calloc(1, sizeof (session_t));
983 
984 	sp->se_index = session_index;
985 
986 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
987 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
988 
989 	/*
990 	 * Attempt to open the device, if we get "device not configured"
991 	 * then don't add the device to the session list.
992 	 */
993 	if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
994 		if (errno == ENXIO) {
995 			free_session(sp);
996 			return (0);
997 		}
998 	} else
999 		close(fd);
1000 
1001 	if (setupargv(sp, typ) == 0) {
1002 		free_session(sp);
1003 		return (0);
1004 	}
1005 
1006 	sp->se_next = 0;
1007 	if (sprev == 0) {
1008 		sessions = sp;
1009 		sp->se_prev = 0;
1010 	} else {
1011 		sprev->se_next = sp;
1012 		sp->se_prev = sprev;
1013 	}
1014 
1015 	return sp;
1016 }
1017 
1018 /*
1019  * Calculate getty and if useful window argv vectors.
1020  */
1021 int
1022 setupargv(sp, typ)
1023 	session_t *sp;
1024 	struct ttyent *typ;
1025 {
1026 
1027 	if (sp->se_getty) {
1028 		free(sp->se_getty);
1029 		free(sp->se_getty_argv_space);
1030 		free(sp->se_getty_argv);
1031 	}
1032 	sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1033 	(void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1034 	sp->se_getty_argv_space = strdup(sp->se_getty);
1035 	sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1036 	if (sp->se_getty_argv == 0) {
1037 		warning("can't parse getty for port %s", sp->se_device);
1038 		free(sp->se_getty);
1039 		free(sp->se_getty_argv_space);
1040 		sp->se_getty = sp->se_getty_argv_space = 0;
1041 		return (0);
1042 	}
1043 	if (sp->se_window) {
1044 		free(sp->se_window);
1045 		free(sp->se_window_argv_space);
1046 		free(sp->se_window_argv);
1047 	}
1048 	sp->se_window = sp->se_window_argv_space = 0;
1049 	sp->se_window_argv = 0;
1050 	if (typ->ty_window) {
1051 		sp->se_window = strdup(typ->ty_window);
1052 		sp->se_window_argv_space = strdup(sp->se_window);
1053 		sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1054 		if (sp->se_window_argv == 0) {
1055 			warning("can't parse window for port %s",
1056 				sp->se_device);
1057 			free(sp->se_window_argv_space);
1058 			free(sp->se_window);
1059 			sp->se_window = sp->se_window_argv_space = 0;
1060 			return (0);
1061 		}
1062 	}
1063 	if (sp->se_type)
1064 		free(sp->se_type);
1065 	sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1066 	return (1);
1067 }
1068 
1069 /*
1070  * Walk the list of ttys and create sessions for each active line.
1071  */
1072 state_func_t
1073 read_ttys()
1074 {
1075 	int session_index = 0;
1076 	register session_t *sp, *snext;
1077 	register struct ttyent *typ;
1078 
1079 	/*
1080 	 * Destroy any previous session state.
1081 	 * There shouldn't be any, but just in case...
1082 	 */
1083 	for (sp = sessions; sp; sp = snext) {
1084 		if (sp->se_process)
1085 			clear_session_logs(sp);
1086 		snext = sp->se_next;
1087 		free_session(sp);
1088 	}
1089 	sessions = 0;
1090 	if (start_session_db())
1091 		return (state_func_t) single_user;
1092 
1093 	/*
1094 	 * Allocate a session entry for each active port.
1095 	 * Note that sp starts at 0.
1096 	 */
1097 	while ((typ = getttyent()) != NULL)
1098 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1099 			sp = snext;
1100 
1101 	endttyent();
1102 
1103 	return (state_func_t) multi_user;
1104 }
1105 
1106 /*
1107  * Start a window system running.
1108  */
1109 void
1110 start_window_system(sp)
1111 	session_t *sp;
1112 {
1113 	pid_t pid;
1114 	sigset_t mask;
1115 	char term[64], *env[2];
1116 
1117 	if ((pid = fork()) == -1) {
1118 		emergency("can't fork for window system on port %s: %m",
1119 			sp->se_device);
1120 		/* hope that getty fails and we can try again */
1121 		return;
1122 	}
1123 
1124 	if (pid)
1125 		return;
1126 
1127 	sigemptyset(&mask);
1128 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1129 
1130 	if (setsid() < 0)
1131 		emergency("setsid failed (window) %m");
1132 
1133 #ifdef LOGIN_CAP
1134 	setprocresources(RESOURCE_WINDOW);
1135 #endif
1136 	if (sp->se_type) {
1137 		/* Don't use malloc after fork */
1138 		strcpy(term, "TERM=");
1139 		strncat(term, sp->se_type, sizeof(term) - 6);
1140 		env[0] = term;
1141 		env[1] = 0;
1142 	}
1143 	else
1144 		env[0] = 0;
1145 	execve(sp->se_window_argv[0], sp->se_window_argv, env);
1146 	stall("can't exec window system '%s' for port %s: %m",
1147 		sp->se_window_argv[0], sp->se_device);
1148 	_exit(1);
1149 }
1150 
1151 /*
1152  * Start a login session running.
1153  */
1154 pid_t
1155 start_getty(sp)
1156 	session_t *sp;
1157 {
1158 	pid_t pid;
1159 	sigset_t mask;
1160 	time_t current_time = time((time_t *) 0);
1161 	int too_quick = 0;
1162 	char term[64], *env[2];
1163 
1164 	if (current_time >= sp->se_started &&
1165 	    current_time - sp->se_started < GETTY_SPACING) {
1166 		if (++sp->se_nspace > GETTY_NSPACE) {
1167 			sp->se_nspace = 0;
1168 			too_quick = 1;
1169 		}
1170 	} else
1171 		sp->se_nspace = 0;
1172 
1173 	/*
1174 	 * fork(), not vfork() -- we can't afford to block.
1175 	 */
1176 	if ((pid = fork()) == -1) {
1177 		emergency("can't fork for getty on port %s: %m", sp->se_device);
1178 		return -1;
1179 	}
1180 
1181 	if (pid)
1182 		return pid;
1183 
1184 	if (too_quick) {
1185 		warning("getty repeating too quickly on port %s, sleeping %d secs",
1186 			sp->se_device, GETTY_SLEEP);
1187 		sleep((unsigned) GETTY_SLEEP);
1188 	}
1189 
1190 	if (sp->se_window) {
1191 		start_window_system(sp);
1192 		sleep(WINDOW_WAIT);
1193 	}
1194 
1195 	sigemptyset(&mask);
1196 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1197 
1198 #ifdef LOGIN_CAP
1199 	setprocresources(RESOURCE_GETTY);
1200 #endif
1201 	if (sp->se_type) {
1202 		/* Don't use malloc after fork */
1203 		strcpy(term, "TERM=");
1204 		strncat(term, sp->se_type, sizeof(term) - 6);
1205 		env[0] = term;
1206 		env[1] = 0;
1207 	}
1208 	else
1209 		env[0] = 0;
1210 	execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1211 	stall("can't exec getty '%s' for port %s: %m",
1212 		sp->se_getty_argv[0], sp->se_device);
1213 	_exit(1);
1214 }
1215 
1216 /*
1217  * Collect exit status for a child.
1218  * If an exiting login, start a new login running.
1219  */
1220 void
1221 #ifdef __STDC__
1222 collect_child(pid_t pid)
1223 #else
1224 collect_child(pid)
1225 	pid_t pid;
1226 #endif
1227 {
1228 	register session_t *sp, *sprev, *snext;
1229 
1230 	if (! sessions)
1231 		return;
1232 
1233 	if (! (sp = find_session(pid)))
1234 		return;
1235 
1236 	clear_session_logs(sp);
1237 	del_session(sp);
1238 	sp->se_process = 0;
1239 
1240 	if (sp->se_flags & SE_SHUTDOWN) {
1241 		if ((sprev = sp->se_prev) != NULL)
1242 			sprev->se_next = sp->se_next;
1243 		else
1244 			sessions = sp->se_next;
1245 		if ((snext = sp->se_next) != NULL)
1246 			snext->se_prev = sp->se_prev;
1247 		free_session(sp);
1248 		return;
1249 	}
1250 
1251 	if ((pid = start_getty(sp)) == -1) {
1252 		/* serious trouble */
1253 		requested_transition = clean_ttys;
1254 		return;
1255 	}
1256 
1257 	sp->se_process = pid;
1258 	sp->se_started = time((time_t *) 0);
1259 	add_session(sp);
1260 }
1261 
1262 /*
1263  * Catch a signal and request a state transition.
1264  */
1265 void
1266 transition_handler(sig)
1267 	int sig;
1268 {
1269 
1270 	switch (sig) {
1271 	case SIGHUP:
1272 		requested_transition = clean_ttys;
1273 		break;
1274 	case SIGUSR2:
1275 		howto = RB_POWEROFF;
1276 	case SIGUSR1:
1277 		howto |= RB_HALT;
1278 	case SIGINT:
1279 		Reboot = TRUE;
1280 	case SIGTERM:
1281 		requested_transition = death;
1282 		break;
1283 	case SIGTSTP:
1284 		requested_transition = catatonia;
1285 		break;
1286 	default:
1287 		requested_transition = 0;
1288 		break;
1289 	}
1290 }
1291 
1292 /*
1293  * Take the system multiuser.
1294  */
1295 state_func_t
1296 multi_user()
1297 {
1298 	pid_t pid;
1299 	register session_t *sp;
1300 
1301 	requested_transition = 0;
1302 
1303 	/*
1304 	 * If the administrator has not set the security level to -1
1305 	 * to indicate that the kernel should not run multiuser in secure
1306 	 * mode, and the run script has not set a higher level of security
1307 	 * than level 1, then put the kernel into secure mode.
1308 	 */
1309 	if (getsecuritylevel() == 0)
1310 		setsecuritylevel(1);
1311 
1312 	for (sp = sessions; sp; sp = sp->se_next) {
1313 		if (sp->se_process)
1314 			continue;
1315 		if ((pid = start_getty(sp)) == -1) {
1316 			/* serious trouble */
1317 			requested_transition = clean_ttys;
1318 			break;
1319 		}
1320 		sp->se_process = pid;
1321 		sp->se_started = time((time_t *) 0);
1322 		add_session(sp);
1323 	}
1324 
1325 	while (!requested_transition)
1326 		if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1327 			collect_child(pid);
1328 
1329 	return (state_func_t) requested_transition;
1330 }
1331 
1332 /*
1333  * This is an n-squared algorithm.  We hope it isn't run often...
1334  */
1335 state_func_t
1336 clean_ttys()
1337 {
1338 	register session_t *sp, *sprev;
1339 	register struct ttyent *typ;
1340 	register int session_index = 0;
1341 	register int devlen;
1342 	char *old_getty, *old_window, *old_type;
1343 
1344 	if (! sessions)
1345 		return (state_func_t) multi_user;
1346 
1347 	devlen = sizeof(_PATH_DEV) - 1;
1348 	while ((typ = getttyent()) != NULL) {
1349 		++session_index;
1350 
1351 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1352 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1353 				break;
1354 
1355 		if (sp) {
1356 			if (sp->se_index != session_index) {
1357 				warning("port %s changed utmp index from %d to %d",
1358 				       sp->se_device, sp->se_index,
1359 				       session_index);
1360 				sp->se_index = session_index;
1361 			}
1362 			if ((typ->ty_status & TTY_ON) == 0 ||
1363 			    typ->ty_getty == 0) {
1364 				sp->se_flags |= SE_SHUTDOWN;
1365 				kill(sp->se_process, SIGHUP);
1366 				continue;
1367 			}
1368 			sp->se_flags &= ~SE_SHUTDOWN;
1369 			old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1370 			old_window = sp->se_window ? strdup(sp->se_window) : 0;
1371 			old_type = sp->se_type ? strdup(sp->se_type) : 0;
1372 			if (setupargv(sp, typ) == 0) {
1373 				warning("can't parse getty for port %s",
1374 					sp->se_device);
1375 				sp->se_flags |= SE_SHUTDOWN;
1376 				kill(sp->se_process, SIGHUP);
1377 			}
1378 			else if (   !old_getty
1379 				 || (!old_type && sp->se_type)
1380 				 || (old_type && !sp->se_type)
1381 				 || (!old_window && sp->se_window)
1382 				 || (old_window && !sp->se_window)
1383 				 || (strcmp(old_getty, sp->se_getty) != 0)
1384 				 || (old_window && strcmp(old_window, sp->se_window) != 0)
1385 				 || (old_type && strcmp(old_type, sp->se_type) != 0)
1386 				) {
1387 				/* Don't set SE_SHUTDOWN here */
1388 				sp->se_nspace = 0;
1389 				sp->se_started = 0;
1390 				kill(sp->se_process, SIGHUP);
1391 			}
1392 			if (old_getty)
1393 				free(old_getty);
1394 			if (old_getty)
1395 				free(old_window);
1396 			if (old_type)
1397 				free(old_type);
1398 			continue;
1399 		}
1400 
1401 		new_session(sprev, session_index, typ);
1402 	}
1403 
1404 	endttyent();
1405 
1406 	return (state_func_t) multi_user;
1407 }
1408 
1409 /*
1410  * Block further logins.
1411  */
1412 state_func_t
1413 catatonia()
1414 {
1415 	register session_t *sp;
1416 
1417 	for (sp = sessions; sp; sp = sp->se_next)
1418 		sp->se_flags |= SE_SHUTDOWN;
1419 
1420 	return (state_func_t) multi_user;
1421 }
1422 
1423 /*
1424  * Note SIGALRM.
1425  */
1426 void
1427 alrm_handler(sig)
1428 	int sig;
1429 {
1430 	(void)sig;
1431 	clang = 1;
1432 }
1433 
1434 /*
1435  * Bring the system down to single user.
1436  */
1437 state_func_t
1438 death()
1439 {
1440 	register session_t *sp;
1441 	register int i;
1442 	pid_t pid;
1443 	static const int death_sigs[2] = { SIGTERM, SIGKILL };
1444 
1445 	/* NB: should send a message to the session logger to avoid blocking. */
1446 	logwtmp("~", "shutdown", "");
1447 
1448 	for (sp = sessions; sp; sp = sp->se_next) {
1449 		sp->se_flags |= SE_SHUTDOWN;
1450 		kill(sp->se_process, SIGHUP);
1451 	}
1452 
1453 	/* Try to run the rc.shutdown script within a period of time */
1454 	(void) runshutdown();
1455 
1456 	for (i = 0; i < 2; ++i) {
1457 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1458 			return (state_func_t) single_user;
1459 
1460 		clang = 0;
1461 		alarm(DEATH_WATCH);
1462 		do
1463 			if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1464 				collect_child(pid);
1465 		while (clang == 0 && errno != ECHILD);
1466 
1467 		if (errno == ECHILD)
1468 			return (state_func_t) single_user;
1469 	}
1470 
1471 	warning("some processes would not die; ps axl advised");
1472 
1473 	return (state_func_t) single_user;
1474 }
1475 
1476 /*
1477  * Run the system shutdown script.
1478  *
1479  * Exit codes:      XXX I should document more
1480  * -2       shutdown script terminated abnormally
1481  * -1       fatal error - can't run script
1482  * 0        good.
1483  * >0       some error (exit code)
1484  */
1485 int
1486 runshutdown()
1487 {
1488 	pid_t pid, wpid;
1489 	int status;
1490 	int shutdowntimeout;
1491 	size_t len;
1492 	char *argv[4];
1493 	struct sigaction sa;
1494 	struct stat sb;
1495 
1496 	/*
1497 	 * rc.shutdown is optional, so to prevent any unnecessary
1498 	 * complaints from the shell we simply don't run it if the
1499 	 * file does not exist. If the stat() here fails for other
1500 	 * reasons, we'll let the shell complain.
1501 	 */
1502 	if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1503 		return 0;
1504 
1505 	if ((pid = fork()) == 0) {
1506 		int	fd;
1507 
1508 		/* Assume that init already grab console as ctty before */
1509 
1510 		sigemptyset(&sa.sa_mask);
1511 		sa.sa_flags = 0;
1512 		sa.sa_handler = SIG_IGN;
1513 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1514 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
1515 
1516 		if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1517 		    warning("can't open %s: %m", _PATH_CONSOLE);
1518 		else {
1519 		    (void) dup2(fd, 0);
1520 		    (void) dup2(fd, 1);
1521 		    (void) dup2(fd, 2);
1522 		    if (fd > 2)
1523 			close(fd);
1524 		}
1525 
1526 		/*
1527 		 * Run the shutdown script.
1528 		 */
1529 		argv[0] = "sh";
1530 		argv[1] = _PATH_RUNDOWN;
1531 		if (Reboot)
1532 			argv[2] = "reboot";
1533 		else
1534 			argv[2] = "single";
1535 		argv[3] = 0;
1536 
1537 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1538 
1539 #ifdef LOGIN_CAP
1540 		setprocresources(RESOURCE_RC);
1541 #endif
1542 		execv(_PATH_BSHELL, argv);
1543 		warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1544 		_exit(1);	/* force single user mode */
1545 	}
1546 
1547 	if (pid == -1) {
1548 		emergency("can't fork for %s on %s: %m",
1549 			_PATH_BSHELL, _PATH_RUNDOWN);
1550 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1551 			continue;
1552 		sleep(STALL_TIMEOUT);
1553 		return -1;
1554 	}
1555 
1556 	len = sizeof(shutdowntimeout);
1557 	if (sysctlbyname("kern.shutdown_timeout",
1558 			 &shutdowntimeout,
1559 			 &len, NULL, 0) == -1 || shutdowntimeout < 2)
1560 	    shutdowntimeout = DEATH_SCRIPT;
1561 	alarm(shutdowntimeout);
1562 	clang = 0;
1563 	/*
1564 	 * Copied from single_user().  This is a bit paranoid.
1565 	 * Use the same ALRM handler.
1566 	 */
1567 	do {
1568 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1569 			collect_child(wpid);
1570 		if (clang == 1) {
1571 			/* we were waiting for the sub-shell */
1572 			kill(wpid, SIGTERM);
1573 			warning("timeout expired for %s on %s: %m; going to single used mode",
1574 				_PATH_BSHELL, _PATH_RUNDOWN);
1575 			return -1;
1576 		}
1577 		if (wpid == -1) {
1578 			if (errno == EINTR)
1579 				continue;
1580 			warning("wait for %s on %s failed: %m; going to single user mode",
1581 				_PATH_BSHELL, _PATH_RUNDOWN);
1582 			return -1;
1583 		}
1584 		if (wpid == pid && WIFSTOPPED(status)) {
1585 			warning("init: %s on %s stopped, restarting\n",
1586 				_PATH_BSHELL, _PATH_RUNDOWN);
1587 			kill(pid, SIGCONT);
1588 			wpid = -1;
1589 		}
1590 	} while (wpid != pid && !clang);
1591 
1592 	/* Turn off the alarm */
1593 	alarm(0);
1594 
1595 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1596 	    requested_transition == catatonia) {
1597 		/*
1598 		 * /etc/rc.shutdown executed /sbin/reboot;
1599 		 * wait for the end quietly
1600 		 */
1601 		sigset_t s;
1602 
1603 		sigfillset(&s);
1604 		for (;;)
1605 			sigsuspend(&s);
1606 	}
1607 
1608 	if (!WIFEXITED(status)) {
1609 		warning("%s on %s terminated abnormally, going to single user mode",
1610 			_PATH_BSHELL, _PATH_RUNDOWN);
1611 		return -2;
1612 	}
1613 
1614 	if ((status = WEXITSTATUS(status)) != 0)
1615 		warning("%s returned status %d", _PATH_RUNDOWN, status);
1616 
1617 	return status;
1618 }
1619 
1620 char *
1621 strk (char *p)
1622 {
1623     static char *t;
1624     char *q;
1625     int c;
1626 
1627     if (p)
1628 	t = p;
1629     if (!t)
1630 	return 0;
1631 
1632     c = *t;
1633     while (c == ' ' || c == '\t' )
1634 	c = *++t;
1635     if (!c) {
1636 	t = 0;
1637 	return 0;
1638     }
1639     q = t;
1640     if (c == '\'') {
1641 	c = *++t;
1642 	q = t;
1643 	while (c && c != '\'')
1644 	    c = *++t;
1645 	if (!c)  /* unterminated string */
1646 	    q = t = 0;
1647 	else
1648 	    *t++ = 0;
1649     } else {
1650 	while (c && c != ' ' && c != '\t' )
1651 	    c = *++t;
1652 	*t++ = 0;
1653 	if (!c)
1654 	    t = 0;
1655     }
1656     return q;
1657 }
1658 
1659 #ifdef LOGIN_CAP
1660 void
1661 setprocresources(cname)
1662 	const char *cname;
1663 {
1664 	login_cap_t *lc;
1665 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1666 		setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1667 		login_close(lc);
1668 	}
1669 }
1670 #endif
1671