xref: /freebsd/sbin/init/init.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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 && pp && *pp->pw_passwd) {
650 			write(2, banner, sizeof banner - 1);
651 			for (;;) {
652 				clear = getpass("Password:");
653 				if (clear == 0 || *clear == '\0')
654 					_exit(0);
655 				password = crypt(clear, pp->pw_passwd);
656 				bzero(clear, _PASSWORD_LEN);
657 				if (strcmp(password, pp->pw_passwd) == 0)
658 					break;
659 				warning("single-user login failed\n");
660 			}
661 		}
662 		endttyent();
663 		endpwent();
664 #endif /* SECURE */
665 
666 #ifdef DEBUGSHELL
667 		{
668 			char *cp = altshell;
669 			int num;
670 
671 #define	SHREQUEST \
672 	"Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
673 			(void)write(STDERR_FILENO,
674 			    SHREQUEST, sizeof(SHREQUEST) - 1);
675 			while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
676 			    num != 0 && *cp != '\n' && cp < &altshell[127])
677 					cp++;
678 			*cp = '\0';
679 			if (altshell[0] != '\0')
680 				shell = altshell;
681 		}
682 #endif /* DEBUGSHELL */
683 
684 		/*
685 		 * Unblock signals.
686 		 * We catch all the interesting ones,
687 		 * and those are reset to SIG_DFL on exec.
688 		 */
689 		sigemptyset(&mask);
690 		sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
691 
692 		/*
693 		 * Fire off a shell.
694 		 * If the default one doesn't work, try the Bourne shell.
695 		 */
696 		argv[0] = "-sh";
697 		argv[1] = 0;
698 		execv(shell, argv);
699 		emergency("can't exec %s for single user: %m", shell);
700 		execv(_PATH_BSHELL, argv);
701 		emergency("can't exec %s for single user: %m", _PATH_BSHELL);
702 		sleep(STALL_TIMEOUT);
703 		_exit(1);
704 	}
705 
706 	if (pid == -1) {
707 		/*
708 		 * We are seriously hosed.  Do our best.
709 		 */
710 		emergency("can't fork single-user shell, trying again");
711 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
712 			continue;
713 		return (state_func_t) single_user;
714 	}
715 
716 	requested_transition = 0;
717 	do {
718 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
719 			collect_child(wpid);
720 		if (wpid == -1) {
721 			if (errno == EINTR)
722 				continue;
723 			warning("wait for single-user shell failed: %m; restarting");
724 			return (state_func_t) single_user;
725 		}
726 		if (wpid == pid && WIFSTOPPED(status)) {
727 			warning("init: shell stopped, restarting\n");
728 			kill(pid, SIGCONT);
729 			wpid = -1;
730 		}
731 	} while (wpid != pid && !requested_transition);
732 
733 	if (requested_transition)
734 		return (state_func_t) requested_transition;
735 
736 	if (!WIFEXITED(status)) {
737 		if (WTERMSIG(status) == SIGKILL) {
738 			/*
739 			 *  reboot(8) killed shell?
740 			 */
741 			warning("single user shell terminated.");
742 			sleep(STALL_TIMEOUT);
743 			_exit(0);
744 		} else {
745 			warning("single user shell terminated, restarting");
746 			return (state_func_t) single_user;
747 		}
748 	}
749 
750 	runcom_mode = FASTBOOT;
751 	return (state_func_t) runcom;
752 }
753 
754 /*
755  * Run the system startup script.
756  */
757 state_func_t
758 runcom()
759 {
760 	pid_t pid, wpid;
761 	int status;
762 	char *argv[4];
763 	struct sigaction sa;
764 
765 	if ((pid = fork()) == 0) {
766 		sigemptyset(&sa.sa_mask);
767 		sa.sa_flags = 0;
768 		sa.sa_handler = SIG_IGN;
769 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
770 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
771 
772 		setctty(_PATH_CONSOLE);
773 
774 		argv[0] = "sh";
775 		argv[1] = _PATH_RUNCOM;
776 		argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
777 		argv[3] = 0;
778 
779 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
780 
781 #ifdef LOGIN_CAP
782 		setprocresources(RESOURCE_RC);
783 #endif
784 		execv(_PATH_BSHELL, argv);
785 		stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
786 		_exit(1);	/* force single user mode */
787 	}
788 
789 	if (pid == -1) {
790 		emergency("can't fork for %s on %s: %m",
791 			_PATH_BSHELL, _PATH_RUNCOM);
792 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
793 			continue;
794 		sleep(STALL_TIMEOUT);
795 		return (state_func_t) single_user;
796 	}
797 
798 	/*
799 	 * Copied from single_user().  This is a bit paranoid.
800 	 */
801 	do {
802 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
803 			collect_child(wpid);
804 		if (wpid == -1) {
805 			if (errno == EINTR)
806 				continue;
807 			warning("wait for %s on %s failed: %m; going to single user mode",
808 				_PATH_BSHELL, _PATH_RUNCOM);
809 			return (state_func_t) single_user;
810 		}
811 		if (wpid == pid && WIFSTOPPED(status)) {
812 			warning("init: %s on %s stopped, restarting\n",
813 				_PATH_BSHELL, _PATH_RUNCOM);
814 			kill(pid, SIGCONT);
815 			wpid = -1;
816 		}
817 	} while (wpid != pid);
818 
819 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
820 	    requested_transition == catatonia) {
821 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
822 		sigset_t s;
823 
824 		sigfillset(&s);
825 		for (;;)
826 			sigsuspend(&s);
827 	}
828 
829 	if (!WIFEXITED(status)) {
830 		warning("%s on %s terminated abnormally, going to single user mode",
831 			_PATH_BSHELL, _PATH_RUNCOM);
832 		return (state_func_t) single_user;
833 	}
834 
835 	if (WEXITSTATUS(status))
836 		return (state_func_t) single_user;
837 
838 	runcom_mode = AUTOBOOT;		/* the default */
839 	/* NB: should send a message to the session logger to avoid blocking. */
840 	logwtmp("~", "reboot", "");
841 	return (state_func_t) read_ttys;
842 }
843 
844 /*
845  * Open the session database.
846  *
847  * NB: We could pass in the size here; is it necessary?
848  */
849 int
850 start_session_db()
851 {
852 	if (session_db && (*session_db->close)(session_db))
853 		emergency("session database close: %s", strerror(errno));
854 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
855 		emergency("session database open: %s", strerror(errno));
856 		return (1);
857 	}
858 	return (0);
859 
860 }
861 
862 /*
863  * Add a new login session.
864  */
865 void
866 add_session(sp)
867 	session_t *sp;
868 {
869 	DBT key;
870 	DBT data;
871 
872 	key.data = &sp->se_process;
873 	key.size = sizeof sp->se_process;
874 	data.data = &sp;
875 	data.size = sizeof sp;
876 
877 	if ((*session_db->put)(session_db, &key, &data, 0))
878 		emergency("insert %d: %s", sp->se_process, strerror(errno));
879 }
880 
881 /*
882  * Delete an old login session.
883  */
884 void
885 del_session(sp)
886 	session_t *sp;
887 {
888 	DBT key;
889 
890 	key.data = &sp->se_process;
891 	key.size = sizeof sp->se_process;
892 
893 	if ((*session_db->del)(session_db, &key, 0))
894 		emergency("delete %d: %s", sp->se_process, strerror(errno));
895 }
896 
897 /*
898  * Look up a login session by pid.
899  */
900 session_t *
901 #ifdef __STDC__
902 find_session(pid_t pid)
903 #else
904 find_session(pid)
905 	pid_t pid;
906 #endif
907 {
908 	DBT key;
909 	DBT data;
910 	session_t *ret;
911 
912 	key.data = &pid;
913 	key.size = sizeof pid;
914 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
915 		return 0;
916 	bcopy(data.data, (char *)&ret, sizeof(ret));
917 	return ret;
918 }
919 
920 /*
921  * Construct an argument vector from a command line.
922  */
923 char **
924 construct_argv(command)
925 	char *command;
926 {
927 	char *strk (char *);
928 	register int argc = 0;
929 	register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
930 						* sizeof (char *));
931 
932 	if ((argv[argc++] = strk(command)) == 0) {
933 		free(argv);
934 		return (NULL);
935 	}
936 	while ((argv[argc++] = strk((char *) 0)) != NULL)
937 		continue;
938 	return argv;
939 }
940 
941 /*
942  * Deallocate a session descriptor.
943  */
944 void
945 free_session(sp)
946 	register session_t *sp;
947 {
948 	free(sp->se_device);
949 	if (sp->se_getty) {
950 		free(sp->se_getty);
951 		free(sp->se_getty_argv_space);
952 		free(sp->se_getty_argv);
953 	}
954 	if (sp->se_window) {
955 		free(sp->se_window);
956 		free(sp->se_window_argv_space);
957 		free(sp->se_window_argv);
958 	}
959 	if (sp->se_type)
960 		free(sp->se_type);
961 	free(sp);
962 }
963 
964 /*
965  * Allocate a new session descriptor.
966  */
967 session_t *
968 new_session(sprev, session_index, typ)
969 	session_t *sprev;
970 	int session_index;
971 	register struct ttyent *typ;
972 {
973 	register session_t *sp;
974 	int fd;
975 
976 	if ((typ->ty_status & TTY_ON) == 0 ||
977 	    typ->ty_name == 0 ||
978 	    typ->ty_getty == 0)
979 		return 0;
980 
981 	sp = (session_t *) calloc(1, sizeof (session_t));
982 
983 	sp->se_index = session_index;
984 
985 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
986 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
987 
988 	/*
989 	 * Attempt to open the device, if we get "device not configured"
990 	 * then don't add the device to the session list.
991 	 */
992 	if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
993 		if (errno == ENXIO) {
994 			free_session(sp);
995 			return (0);
996 		}
997 	} else
998 		close(fd);
999 
1000 	if (setupargv(sp, typ) == 0) {
1001 		free_session(sp);
1002 		return (0);
1003 	}
1004 
1005 	sp->se_next = 0;
1006 	if (sprev == 0) {
1007 		sessions = sp;
1008 		sp->se_prev = 0;
1009 	} else {
1010 		sprev->se_next = sp;
1011 		sp->se_prev = sprev;
1012 	}
1013 
1014 	return sp;
1015 }
1016 
1017 /*
1018  * Calculate getty and if useful window argv vectors.
1019  */
1020 int
1021 setupargv(sp, typ)
1022 	session_t *sp;
1023 	struct ttyent *typ;
1024 {
1025 
1026 	if (sp->se_getty) {
1027 		free(sp->se_getty);
1028 		free(sp->se_getty_argv_space);
1029 		free(sp->se_getty_argv);
1030 	}
1031 	sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1032 	(void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1033 	sp->se_getty_argv_space = strdup(sp->se_getty);
1034 	sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1035 	if (sp->se_getty_argv == 0) {
1036 		warning("can't parse getty for port %s", sp->se_device);
1037 		free(sp->se_getty);
1038 		free(sp->se_getty_argv_space);
1039 		sp->se_getty = sp->se_getty_argv_space = 0;
1040 		return (0);
1041 	}
1042 	if (sp->se_window) {
1043 		free(sp->se_window);
1044 		free(sp->se_window_argv_space);
1045 		free(sp->se_window_argv);
1046 	}
1047 	sp->se_window = sp->se_window_argv_space = 0;
1048 	sp->se_window_argv = 0;
1049 	if (typ->ty_window) {
1050 		sp->se_window = strdup(typ->ty_window);
1051 		sp->se_window_argv_space = strdup(sp->se_window);
1052 		sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1053 		if (sp->se_window_argv == 0) {
1054 			warning("can't parse window for port %s",
1055 				sp->se_device);
1056 			free(sp->se_window_argv_space);
1057 			free(sp->se_window);
1058 			sp->se_window = sp->se_window_argv_space = 0;
1059 			return (0);
1060 		}
1061 	}
1062 	if (sp->se_type)
1063 		free(sp->se_type);
1064 	sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1065 	return (1);
1066 }
1067 
1068 /*
1069  * Walk the list of ttys and create sessions for each active line.
1070  */
1071 state_func_t
1072 read_ttys()
1073 {
1074 	int session_index = 0;
1075 	register session_t *sp, *snext;
1076 	register struct ttyent *typ;
1077 
1078 	/*
1079 	 * Destroy any previous session state.
1080 	 * There shouldn't be any, but just in case...
1081 	 */
1082 	for (sp = sessions; sp; sp = snext) {
1083 		if (sp->se_process)
1084 			clear_session_logs(sp);
1085 		snext = sp->se_next;
1086 		free_session(sp);
1087 	}
1088 	sessions = 0;
1089 	if (start_session_db())
1090 		return (state_func_t) single_user;
1091 
1092 	/*
1093 	 * Allocate a session entry for each active port.
1094 	 * Note that sp starts at 0.
1095 	 */
1096 	while ((typ = getttyent()) != NULL)
1097 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1098 			sp = snext;
1099 
1100 	endttyent();
1101 
1102 	return (state_func_t) multi_user;
1103 }
1104 
1105 /*
1106  * Start a window system running.
1107  */
1108 void
1109 start_window_system(sp)
1110 	session_t *sp;
1111 {
1112 	pid_t pid;
1113 	sigset_t mask;
1114 	char term[64], *env[2];
1115 
1116 	if ((pid = fork()) == -1) {
1117 		emergency("can't fork for window system on port %s: %m",
1118 			sp->se_device);
1119 		/* hope that getty fails and we can try again */
1120 		return;
1121 	}
1122 
1123 	if (pid)
1124 		return;
1125 
1126 	sigemptyset(&mask);
1127 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1128 
1129 	if (setsid() < 0)
1130 		emergency("setsid failed (window) %m");
1131 
1132 #ifdef LOGIN_CAP
1133 	setprocresources(RESOURCE_WINDOW);
1134 #endif
1135 	if (sp->se_type) {
1136 		/* Don't use malloc after fork */
1137 		strcpy(term, "TERM=");
1138 		strncat(term, sp->se_type, sizeof(term) - 6);
1139 		env[0] = term;
1140 		env[1] = 0;
1141 	}
1142 	else
1143 		env[0] = 0;
1144 	execve(sp->se_window_argv[0], sp->se_window_argv, env);
1145 	stall("can't exec window system '%s' for port %s: %m",
1146 		sp->se_window_argv[0], sp->se_device);
1147 	_exit(1);
1148 }
1149 
1150 /*
1151  * Start a login session running.
1152  */
1153 pid_t
1154 start_getty(sp)
1155 	session_t *sp;
1156 {
1157 	pid_t pid;
1158 	sigset_t mask;
1159 	time_t current_time = time((time_t *) 0);
1160 	int too_quick = 0;
1161 	char term[64], *env[2];
1162 
1163 	if (current_time >= sp->se_started &&
1164 	    current_time - sp->se_started < GETTY_SPACING) {
1165 		if (++sp->se_nspace > GETTY_NSPACE) {
1166 			sp->se_nspace = 0;
1167 			too_quick = 1;
1168 		}
1169 	} else
1170 		sp->se_nspace = 0;
1171 
1172 	/*
1173 	 * fork(), not vfork() -- we can't afford to block.
1174 	 */
1175 	if ((pid = fork()) == -1) {
1176 		emergency("can't fork for getty on port %s: %m", sp->se_device);
1177 		return -1;
1178 	}
1179 
1180 	if (pid)
1181 		return pid;
1182 
1183 	if (too_quick) {
1184 		warning("getty repeating too quickly on port %s, sleeping %d secs",
1185 			sp->se_device, GETTY_SLEEP);
1186 		sleep((unsigned) GETTY_SLEEP);
1187 	}
1188 
1189 	if (sp->se_window) {
1190 		start_window_system(sp);
1191 		sleep(WINDOW_WAIT);
1192 	}
1193 
1194 	sigemptyset(&mask);
1195 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1196 
1197 #ifdef LOGIN_CAP
1198 	setprocresources(RESOURCE_GETTY);
1199 #endif
1200 	if (sp->se_type) {
1201 		/* Don't use malloc after fork */
1202 		strcpy(term, "TERM=");
1203 		strncat(term, sp->se_type, sizeof(term) - 6);
1204 		env[0] = term;
1205 		env[1] = 0;
1206 	}
1207 	else
1208 		env[0] = 0;
1209 	execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1210 	stall("can't exec getty '%s' for port %s: %m",
1211 		sp->se_getty_argv[0], sp->se_device);
1212 	_exit(1);
1213 }
1214 
1215 /*
1216  * Collect exit status for a child.
1217  * If an exiting login, start a new login running.
1218  */
1219 void
1220 #ifdef __STDC__
1221 collect_child(pid_t pid)
1222 #else
1223 collect_child(pid)
1224 	pid_t pid;
1225 #endif
1226 {
1227 	register session_t *sp, *sprev, *snext;
1228 
1229 	if (! sessions)
1230 		return;
1231 
1232 	if (! (sp = find_session(pid)))
1233 		return;
1234 
1235 	clear_session_logs(sp);
1236 	del_session(sp);
1237 	sp->se_process = 0;
1238 
1239 	if (sp->se_flags & SE_SHUTDOWN) {
1240 		if ((sprev = sp->se_prev) != NULL)
1241 			sprev->se_next = sp->se_next;
1242 		else
1243 			sessions = sp->se_next;
1244 		if ((snext = sp->se_next) != NULL)
1245 			snext->se_prev = sp->se_prev;
1246 		free_session(sp);
1247 		return;
1248 	}
1249 
1250 	if ((pid = start_getty(sp)) == -1) {
1251 		/* serious trouble */
1252 		requested_transition = clean_ttys;
1253 		return;
1254 	}
1255 
1256 	sp->se_process = pid;
1257 	sp->se_started = time((time_t *) 0);
1258 	add_session(sp);
1259 }
1260 
1261 /*
1262  * Catch a signal and request a state transition.
1263  */
1264 void
1265 transition_handler(sig)
1266 	int sig;
1267 {
1268 
1269 	switch (sig) {
1270 	case SIGHUP:
1271 		requested_transition = clean_ttys;
1272 		break;
1273 	case SIGUSR2:
1274 		howto = RB_POWEROFF;
1275 	case SIGUSR1:
1276 		howto |= RB_HALT;
1277 	case SIGINT:
1278 		Reboot = TRUE;
1279 	case SIGTERM:
1280 		requested_transition = death;
1281 		break;
1282 	case SIGTSTP:
1283 		requested_transition = catatonia;
1284 		break;
1285 	default:
1286 		requested_transition = 0;
1287 		break;
1288 	}
1289 }
1290 
1291 /*
1292  * Take the system multiuser.
1293  */
1294 state_func_t
1295 multi_user()
1296 {
1297 	pid_t pid;
1298 	register session_t *sp;
1299 
1300 	requested_transition = 0;
1301 
1302 	/*
1303 	 * If the administrator has not set the security level to -1
1304 	 * to indicate that the kernel should not run multiuser in secure
1305 	 * mode, and the run script has not set a higher level of security
1306 	 * than level 1, then put the kernel into secure mode.
1307 	 */
1308 	if (getsecuritylevel() == 0)
1309 		setsecuritylevel(1);
1310 
1311 	for (sp = sessions; sp; sp = sp->se_next) {
1312 		if (sp->se_process)
1313 			continue;
1314 		if ((pid = start_getty(sp)) == -1) {
1315 			/* serious trouble */
1316 			requested_transition = clean_ttys;
1317 			break;
1318 		}
1319 		sp->se_process = pid;
1320 		sp->se_started = time((time_t *) 0);
1321 		add_session(sp);
1322 	}
1323 
1324 	while (!requested_transition)
1325 		if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1326 			collect_child(pid);
1327 
1328 	return (state_func_t) requested_transition;
1329 }
1330 
1331 /*
1332  * This is an n-squared algorithm.  We hope it isn't run often...
1333  */
1334 state_func_t
1335 clean_ttys()
1336 {
1337 	register session_t *sp, *sprev;
1338 	register struct ttyent *typ;
1339 	register int session_index = 0;
1340 	register int devlen;
1341 	char *old_getty, *old_window, *old_type;
1342 
1343 	if (! sessions)
1344 		return (state_func_t) multi_user;
1345 
1346 	devlen = sizeof(_PATH_DEV) - 1;
1347 	while ((typ = getttyent()) != NULL) {
1348 		++session_index;
1349 
1350 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1351 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1352 				break;
1353 
1354 		if (sp) {
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_getty)
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 	return (state_func_t) multi_user;
1406 }
1407 
1408 /*
1409  * Block further logins.
1410  */
1411 state_func_t
1412 catatonia()
1413 {
1414 	register session_t *sp;
1415 
1416 	for (sp = sessions; sp; sp = sp->se_next)
1417 		sp->se_flags |= SE_SHUTDOWN;
1418 
1419 	return (state_func_t) multi_user;
1420 }
1421 
1422 /*
1423  * Note SIGALRM.
1424  */
1425 void
1426 alrm_handler(sig)
1427 	int sig;
1428 {
1429 	(void)sig;
1430 	clang = 1;
1431 }
1432 
1433 /*
1434  * Bring the system down to single user.
1435  */
1436 state_func_t
1437 death()
1438 {
1439 	register session_t *sp;
1440 	register int i;
1441 	pid_t pid;
1442 	static const int death_sigs[2] = { SIGTERM, SIGKILL };
1443 
1444 	/* NB: should send a message to the session logger to avoid blocking. */
1445 	logwtmp("~", "shutdown", "");
1446 
1447 	for (sp = sessions; sp; sp = sp->se_next) {
1448 		sp->se_flags |= SE_SHUTDOWN;
1449 		kill(sp->se_process, SIGHUP);
1450 	}
1451 
1452 	/* Try to run the rc.shutdown script within a period of time */
1453 	(void) runshutdown();
1454 
1455 	for (i = 0; i < 2; ++i) {
1456 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1457 			return (state_func_t) single_user;
1458 
1459 		clang = 0;
1460 		alarm(DEATH_WATCH);
1461 		do
1462 			if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1463 				collect_child(pid);
1464 		while (clang == 0 && errno != ECHILD);
1465 
1466 		if (errno == ECHILD)
1467 			return (state_func_t) single_user;
1468 	}
1469 
1470 	warning("some processes would not die; ps axl advised");
1471 
1472 	return (state_func_t) single_user;
1473 }
1474 
1475 /*
1476  * Run the system shutdown script.
1477  *
1478  * Exit codes:      XXX I should document more
1479  * -2       shutdown script terminated abnormally
1480  * -1       fatal error - can't run script
1481  * 0        good.
1482  * >0       some error (exit code)
1483  */
1484 int
1485 runshutdown()
1486 {
1487 	pid_t pid, wpid;
1488 	int status;
1489 	int shutdowntimeout;
1490 	size_t len;
1491 	char *argv[3];
1492 	struct sigaction sa;
1493 	struct stat sb;
1494 
1495 	/*
1496 	 * rc.shutdown is optional, so to prevent any unnecessary
1497 	 * complaints from the shell we simply don't run it if the
1498 	 * file does not exist. If the stat() here fails for other
1499 	 * reasons, we'll let the shell complain.
1500 	 */
1501 	if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1502 		return 0;
1503 
1504 	if ((pid = fork()) == 0) {
1505 		int	fd;
1506 
1507 		/* Assume that init already grab console as ctty before */
1508 
1509 		sigemptyset(&sa.sa_mask);
1510 		sa.sa_flags = 0;
1511 		sa.sa_handler = SIG_IGN;
1512 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1513 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
1514 
1515 		if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1516 		    warning("can't open %s: %m", _PATH_CONSOLE);
1517 		else {
1518 		    (void) dup2(fd, 0);
1519 		    (void) dup2(fd, 1);
1520 		    (void) dup2(fd, 2);
1521 		    if (fd > 2)
1522 			close(fd);
1523 		}
1524 
1525 		/*
1526 		 * Run the shutdown script.
1527 		 */
1528 		argv[0] = "sh";
1529 		argv[1] = _PATH_RUNDOWN;
1530 		argv[2] = 0;
1531 
1532 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1533 
1534 #ifdef LOGIN_CAP
1535 		setprocresources(RESOURCE_RC);
1536 #endif
1537 		execv(_PATH_BSHELL, argv);
1538 		warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1539 		_exit(1);	/* force single user mode */
1540 	}
1541 
1542 	if (pid == -1) {
1543 		emergency("can't fork for %s on %s: %m",
1544 			_PATH_BSHELL, _PATH_RUNDOWN);
1545 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1546 			continue;
1547 		sleep(STALL_TIMEOUT);
1548 		return -1;
1549 	}
1550 
1551 	len = sizeof(shutdowntimeout);
1552 	if (sysctlbyname("kern.shutdown_timeout",
1553 			 &shutdowntimeout,
1554 			 &len, NULL, 0) == -1 || shutdowntimeout < 2)
1555 	    shutdowntimeout = DEATH_SCRIPT;
1556 	alarm(shutdowntimeout);
1557 	clang = 0;
1558 	/*
1559 	 * Copied from single_user().  This is a bit paranoid.
1560 	 * Use the same ALRM handler.
1561 	 */
1562 	do {
1563 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1564 			collect_child(wpid);
1565 		if (clang == 1) {
1566 			/* we were waiting for the sub-shell */
1567 			kill(wpid, SIGTERM);
1568 			warning("timeout expired for %s on %s: %m; going to single used mode",
1569 				_PATH_BSHELL, _PATH_RUNDOWN);
1570 			return -1;
1571 		}
1572 		if (wpid == -1) {
1573 			if (errno == EINTR)
1574 				continue;
1575 			warning("wait for %s on %s failed: %m; going to single user mode",
1576 				_PATH_BSHELL, _PATH_RUNDOWN);
1577 			return -1;
1578 		}
1579 		if (wpid == pid && WIFSTOPPED(status)) {
1580 			warning("init: %s on %s stopped, restarting\n",
1581 				_PATH_BSHELL, _PATH_RUNDOWN);
1582 			kill(pid, SIGCONT);
1583 			wpid = -1;
1584 		}
1585 	} while (wpid != pid && !clang);
1586 
1587 	/* Turn off the alarm */
1588 	alarm(0);
1589 
1590 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1591 	    requested_transition == catatonia) {
1592 		/*
1593 		 * /etc/rc.shutdown executed /sbin/reboot;
1594 		 * wait for the end quietly
1595 		 */
1596 		sigset_t s;
1597 
1598 		sigfillset(&s);
1599 		for (;;)
1600 			sigsuspend(&s);
1601 	}
1602 
1603 	if (!WIFEXITED(status)) {
1604 		warning("%s on %s terminated abnormally, going to single user mode",
1605 			_PATH_BSHELL, _PATH_RUNDOWN);
1606 		return -2;
1607 	}
1608 
1609 	if ((status = WEXITSTATUS(status)) != 0)
1610 		warning("%s returned status %d", _PATH_RUNDOWN, status);
1611 
1612 	return status;
1613 }
1614 
1615 char *
1616 strk (char *p)
1617 {
1618     static char *t;
1619     char *q;
1620     int c;
1621 
1622     if (p)
1623 	t = p;
1624     if (!t)
1625 	return 0;
1626 
1627     c = *t;
1628     while (c == ' ' || c == '\t' )
1629 	c = *++t;
1630     if (!c) {
1631 	t = 0;
1632 	return 0;
1633     }
1634     q = t;
1635     if (c == '\'') {
1636 	c = *++t;
1637 	q = t;
1638 	while (c && c != '\'')
1639 	    c = *++t;
1640 	if (!c)  /* unterminated string */
1641 	    q = t = 0;
1642 	else
1643 	    *t++ = 0;
1644     } else {
1645 	while (c && c != ' ' && c != '\t' )
1646 	    c = *++t;
1647 	*t++ = 0;
1648 	if (!c)
1649 	    t = 0;
1650     }
1651     return q;
1652 }
1653 
1654 #ifdef LOGIN_CAP
1655 void
1656 setprocresources(cname)
1657 	const char *cname;
1658 {
1659 	login_cap_t *lc;
1660 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1661 		setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1662 		login_close(lc);
1663 	}
1664 }
1665 #endif
1666