xref: /freebsd/sbin/init/init.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Donn Seeley at Berkeley Software Design, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1991, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)init.c	8.1 (Berkeley) 7/15/93";
42 #endif
43 static const char rcsid[] =
44   "$FreeBSD$";
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/ioctl.h>
49 #include <sys/mount.h>
50 #include <sys/sysctl.h>
51 #include <sys/wait.h>
52 #include <sys/stat.h>
53 #include <sys/uio.h>
54 
55 #include <db.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <libutil.h>
59 #include <paths.h>
60 #include <signal.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <syslog.h>
65 #include <time.h>
66 #include <ttyent.h>
67 #include <unistd.h>
68 #include <sys/reboot.h>
69 #include <err.h>
70 
71 #include <stdarg.h>
72 
73 #ifdef SECURE
74 #include <pwd.h>
75 #endif
76 
77 #ifdef LOGIN_CAP
78 #include <login_cap.h>
79 #endif
80 
81 #include "pathnames.h"
82 
83 /*
84  * Sleep times; used to prevent thrashing.
85  */
86 #define	GETTY_SPACING		 5	/* N secs minimum getty spacing */
87 #define	GETTY_SLEEP		30	/* sleep N secs after spacing problem */
88 #define GETTY_NSPACE             3      /* max. spacing count to bring reaction */
89 #define	WINDOW_WAIT		 3	/* wait N secs after starting window */
90 #define	STALL_TIMEOUT		30	/* wait N secs after warning */
91 #define	DEATH_WATCH		10	/* wait N secs for procs to die */
92 #define DEATH_SCRIPT		120	/* wait for 2min for /etc/rc.shutdown */
93 #define RESOURCE_RC		"daemon"
94 #define RESOURCE_WINDOW 	"default"
95 #define RESOURCE_GETTY		"default"
96 
97 void handle(sig_t, ...);
98 void delset(sigset_t *, ...);
99 
100 void stall(const char *, ...) __printflike(1, 2);
101 void warning(const char *, ...) __printflike(1, 2);
102 void emergency(const char *, ...) __printflike(1, 2);
103 void disaster(int);
104 void badsys(int);
105 int  runshutdown(void);
106 
107 /*
108  * We really need a recursive typedef...
109  * The following at least guarantees that the return type of (*state_t)()
110  * is sufficiently wide to hold a function pointer.
111  */
112 typedef long (*state_func_t)(void);
113 typedef state_func_t (*state_t)(void);
114 
115 state_func_t single_user(void);
116 state_func_t runcom(void);
117 state_func_t read_ttys(void);
118 state_func_t multi_user(void);
119 state_func_t clean_ttys(void);
120 state_func_t catatonia(void);
121 state_func_t death(void);
122 
123 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
124 #define FALSE	0
125 #define TRUE	1
126 
127 int Reboot = FALSE;
128 int howto = RB_AUTOBOOT;
129 
130 int devfs;
131 
132 void transition(state_t);
133 state_t requested_transition = runcom;
134 
135 void setctty(char *);
136 
137 typedef struct init_session {
138 	int	se_index;		/* index of entry in ttys file */
139 	pid_t	se_process;		/* controlling process */
140 	time_t	se_started;		/* used to avoid thrashing */
141 	int	se_flags;		/* status of session */
142 #define	SE_SHUTDOWN	0x1		/* session won't be restarted */
143 #define	SE_PRESENT	0x2		/* session is in /etc/ttys */
144 	int     se_nspace;              /* spacing count */
145 	char	*se_device;		/* filename of port */
146 	char	*se_getty;		/* what to run on that port */
147 	char    *se_getty_argv_space;   /* pre-parsed argument array space */
148 	char	**se_getty_argv;	/* pre-parsed argument array */
149 	char	*se_window;		/* window system (started only once) */
150 	char    *se_window_argv_space;  /* pre-parsed argument array space */
151 	char	**se_window_argv;	/* pre-parsed argument array */
152 	char    *se_type;               /* default terminal type */
153 	struct	init_session *se_prev;
154 	struct	init_session *se_next;
155 } session_t;
156 
157 void free_session(session_t *);
158 session_t *new_session(session_t *, int, struct ttyent *);
159 session_t *sessions;
160 
161 char **construct_argv(char *);
162 void start_window_system(session_t *);
163 void collect_child(pid_t);
164 pid_t start_getty(session_t *);
165 void transition_handler(int);
166 void alrm_handler(int);
167 void setsecuritylevel(int);
168 int getsecuritylevel(void);
169 int setupargv(session_t *, struct ttyent *);
170 #ifdef LOGIN_CAP
171 void setprocresources(const char *);
172 #endif
173 int clang;
174 
175 void clear_session_logs(session_t *);
176 
177 int start_session_db(void);
178 void add_session(session_t *);
179 void del_session(session_t *);
180 session_t *find_session(pid_t);
181 DB *session_db;
182 
183 /*
184  * The mother of all processes.
185  */
186 int
187 main(int argc, char *argv[])
188 {
189 	int c;
190 	struct sigaction sa;
191 	sigset_t mask;
192 
193 
194 	/* Dispose of random users. */
195 	if (getuid() != 0)
196 		errx(1, "%s", strerror(EPERM));
197 
198 	/* System V users like to reexec init. */
199 	if (getpid() != 1) {
200 #ifdef COMPAT_SYSV_INIT
201 		/* So give them what they want */
202 		if (argc > 1) {
203 			if (strlen(argv[1]) == 1) {
204 				char runlevel = *argv[1];
205 				int sig;
206 
207 				switch (runlevel) {
208 					case '0': /* halt + poweroff */
209 						sig = SIGUSR2;
210 						break;
211 					case '1': /* single-user */
212 						sig = SIGTERM;
213 						break;
214 					case '6': /* reboot */
215 						sig = SIGINT;
216 						break;
217 					case 'c': /* block further logins */
218 						sig = SIGTSTP;
219 						break;
220 					case 'q': /* rescan /etc/ttys */
221 						sig = SIGHUP;
222 						break;
223 					default:
224 						goto invalid;
225 				}
226 				kill(1, sig);
227 				_exit(0);
228 			} else
229 invalid:
230 				errx(1, "invalid run-level ``%s''", argv[1]);
231 		} else
232 #endif
233 			errx(1, "already running");
234 	}
235 	/*
236 	 * Note that this does NOT open a file...
237 	 * Does 'init' deserve its own facility number?
238 	 */
239 	openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
240 
241 	/*
242 	 * Create an initial session.
243 	 */
244 	if (setsid() < 0)
245 		warning("initial setsid() failed: %m");
246 
247 	/*
248 	 * Establish an initial user so that programs running
249 	 * single user do not freak out and die (like passwd).
250 	 */
251 	if (setlogin("root") < 0)
252 		warning("setlogin() failed: %m");
253 
254 	/*
255 	 * This code assumes that we always get arguments through flags,
256 	 * never through bits set in some random machine register.
257 	 */
258 	while ((c = getopt(argc, argv, "dsf")) != -1)
259 		switch (c) {
260 		case 'd':
261 			devfs = 1;
262 			break;
263 		case 's':
264 			requested_transition = single_user;
265 			break;
266 		case 'f':
267 			runcom_mode = FASTBOOT;
268 			break;
269 		default:
270 			warning("unrecognized flag '-%c'", c);
271 			break;
272 		}
273 
274 	if (optind != argc)
275 		warning("ignoring excess arguments");
276 
277 	if (devfs) {
278 		struct iovec iov[4];
279 		char *s;
280 		int i;
281 
282 		iov[0].iov_base = "fstype";
283 		iov[0].iov_len = sizeof("fstype");
284 		iov[1].iov_base = "devfs";
285 		iov[1].iov_len = sizeof("devfs");
286 		iov[2].iov_base = "fspath";
287 		iov[2].iov_len = sizeof("fspath");
288 		/*
289 		 * Try to avoid the trailing slash in _PATH_DEV.
290 		 * Be *very* defensive.
291 		 */
292 		s = strdup(_PATH_DEV);
293 		if (s != NULL) {
294 			i = strlen(s);
295 			if (i > 0 && s[i - 1] == '/')
296 				s[i - 1] = '\0';
297 			iov[3].iov_base = s;
298 			iov[3].iov_len = strlen(s) + 1;
299 		} else {
300 			iov[3].iov_base = _PATH_DEV;
301 			iov[3].iov_len = sizeof(_PATH_DEV);
302 		}
303 		nmount(iov, 4, 0);
304 		if (s != NULL)
305 			free(s);
306 	}
307 
308 	/*
309 	 * We catch or block signals rather than ignore them,
310 	 * so that they get reset on exec.
311 	 */
312 	handle(badsys, SIGSYS, 0);
313 	handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
314 	       SIGBUS, SIGXCPU, SIGXFSZ, 0);
315 	handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP,
316 		SIGUSR1, SIGUSR2, 0);
317 	handle(alrm_handler, SIGALRM, 0);
318 	sigfillset(&mask);
319 	delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
320 		SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
321 		SIGUSR1, SIGUSR2, 0);
322 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
323 	sigemptyset(&sa.sa_mask);
324 	sa.sa_flags = 0;
325 	sa.sa_handler = SIG_IGN;
326 	(void) sigaction(SIGTTIN, &sa, (struct sigaction *)0);
327 	(void) sigaction(SIGTTOU, &sa, (struct sigaction *)0);
328 
329 	/*
330 	 * Paranoia.
331 	 */
332 	close(0);
333 	close(1);
334 	close(2);
335 
336 	/*
337 	 * Start the state machine.
338 	 */
339 	transition(requested_transition);
340 
341 	/*
342 	 * Should never reach here.
343 	 */
344 	return 1;
345 }
346 
347 /*
348  * Associate a function with a signal handler.
349  */
350 void
351 handle(sig_t handler, ...)
352 {
353 	int sig;
354 	struct sigaction sa;
355 	sigset_t mask_everything;
356 	va_list ap;
357 	va_start(ap, handler);
358 
359 	sa.sa_handler = handler;
360 	sigfillset(&mask_everything);
361 
362 	while ((sig = va_arg(ap, int)) != 0) {
363 		sa.sa_mask = mask_everything;
364 		/* XXX SA_RESTART? */
365 		sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
366 		sigaction(sig, &sa, (struct sigaction *) 0);
367 	}
368 	va_end(ap);
369 }
370 
371 /*
372  * Delete a set of signals from a mask.
373  */
374 void
375 delset(sigset_t *maskp, ...)
376 {
377 	int sig;
378 	va_list ap;
379 	va_start(ap, maskp);
380 
381 	while ((sig = va_arg(ap, int)) != 0)
382 		sigdelset(maskp, sig);
383 	va_end(ap);
384 }
385 
386 /*
387  * Log a message and sleep for a while (to give someone an opportunity
388  * to read it and to save log or hardcopy output if the problem is chronic).
389  * NB: should send a message to the session logger to avoid blocking.
390  */
391 void
392 stall(const char *message, ...)
393 {
394 	va_list ap;
395 	va_start(ap, message);
396 
397 	vsyslog(LOG_ALERT, message, ap);
398 	va_end(ap);
399 	sleep(STALL_TIMEOUT);
400 }
401 
402 /*
403  * Like stall(), but doesn't sleep.
404  * If cpp had variadic macros, the two functions could be #defines for another.
405  * NB: should send a message to the session logger to avoid blocking.
406  */
407 void
408 warning(const char *message, ...)
409 {
410 	va_list ap;
411 	va_start(ap, message);
412 
413 	vsyslog(LOG_ALERT, message, ap);
414 	va_end(ap);
415 }
416 
417 /*
418  * Log an emergency message.
419  * NB: should send a message to the session logger to avoid blocking.
420  */
421 void
422 emergency(const char *message, ...)
423 {
424 	va_list ap;
425 	va_start(ap, message);
426 
427 	vsyslog(LOG_EMERG, message, ap);
428 	va_end(ap);
429 }
430 
431 /*
432  * Catch a SIGSYS signal.
433  *
434  * These may arise if a system does not support sysctl.
435  * We tolerate up to 25 of these, then throw in the towel.
436  */
437 void
438 badsys(int sig)
439 {
440 	static int badcount = 0;
441 
442 	if (badcount++ < 25)
443 		return;
444 	disaster(sig);
445 }
446 
447 /*
448  * Catch an unexpected signal.
449  */
450 void
451 disaster(int sig)
452 {
453 	emergency("fatal signal: %s",
454 		(unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
455 
456 	sleep(STALL_TIMEOUT);
457 	_exit(sig);		/* reboot */
458 }
459 
460 /*
461  * Get the security level of the kernel.
462  */
463 int
464 getsecuritylevel(void)
465 {
466 #ifdef KERN_SECURELVL
467 	int name[2], curlevel;
468 	size_t len;
469 
470 	name[0] = CTL_KERN;
471 	name[1] = KERN_SECURELVL;
472 	len = sizeof curlevel;
473 	if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
474 		emergency("cannot get kernel security level: %s",
475 		    strerror(errno));
476 		return (-1);
477 	}
478 	return (curlevel);
479 #else
480 	return (-1);
481 #endif
482 }
483 
484 /*
485  * Set the security level of the kernel.
486  */
487 void
488 setsecuritylevel(int newlevel)
489 {
490 #ifdef KERN_SECURELVL
491 	int name[2], curlevel;
492 
493 	curlevel = getsecuritylevel();
494 	if (newlevel == curlevel)
495 		return;
496 	name[0] = CTL_KERN;
497 	name[1] = KERN_SECURELVL;
498 	if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
499 		emergency(
500 		    "cannot change kernel security level from %d to %d: %s",
501 		    curlevel, newlevel, strerror(errno));
502 		return;
503 	}
504 #ifdef SECURE
505 	warning("kernel security level changed from %d to %d",
506 	    curlevel, newlevel);
507 #endif
508 #endif
509 }
510 
511 /*
512  * Change states in the finite state machine.
513  * The initial state is passed as an argument.
514  */
515 void
516 transition(state_t s)
517 {
518 	for (;;)
519 		s = (state_t) (*s)();
520 }
521 
522 /*
523  * Close out the accounting files for a login session.
524  * NB: should send a message to the session logger to avoid blocking.
525  */
526 void
527 clear_session_logs(session_t *sp)
528 {
529 	char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
530 
531 	if (logout(line))
532 		logwtmp(line, "", "");
533 }
534 
535 /*
536  * Start a session and allocate a controlling terminal.
537  * Only called by children of init after forking.
538  */
539 void
540 setctty(char *name)
541 {
542 	int fd;
543 
544 	(void) revoke(name);
545 	if ((fd = open(name, O_RDWR)) == -1) {
546 		stall("can't open %s: %m", name);
547 		_exit(1);
548 	}
549 	if (login_tty(fd) == -1) {
550 		stall("can't get %s for controlling terminal: %m", name);
551 		_exit(1);
552 	}
553 }
554 
555 /*
556  * Bring the system up single user.
557  */
558 state_func_t
559 single_user(void)
560 {
561 	pid_t pid, wpid;
562 	int status;
563 	sigset_t mask;
564 	char *shell = _PATH_BSHELL;
565 	char *argv[2];
566 #ifdef SECURE
567 	struct ttyent *typ;
568 	struct passwd *pp;
569 	static const char banner[] =
570 		"Enter root password, or ^D to go multi-user\n";
571 	char *clear, *password;
572 #endif
573 #ifdef DEBUGSHELL
574 	char altshell[128];
575 #endif
576 
577 	if (Reboot) {
578 		/* Instead of going single user, let's reboot the machine */
579 		sync();
580 		alarm(2);
581 		pause();
582 		reboot(howto);
583 		_exit(0);
584 	}
585 
586 	if ((pid = fork()) == 0) {
587 		/*
588 		 * Start the single user session.
589 		 */
590 		setctty(_PATH_CONSOLE);
591 
592 #ifdef SECURE
593 		/*
594 		 * Check the root password.
595 		 * We don't care if the console is 'on' by default;
596 		 * it's the only tty that can be 'off' and 'secure'.
597 		 */
598 		typ = getttynam("console");
599 		pp = getpwnam("root");
600 		if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
601 		    pp && *pp->pw_passwd) {
602 			write(STDERR_FILENO, banner, sizeof banner - 1);
603 			for (;;) {
604 				clear = getpass("Password:");
605 				if (clear == 0 || *clear == '\0')
606 					_exit(0);
607 				password = crypt(clear, pp->pw_passwd);
608 				bzero(clear, _PASSWORD_LEN);
609 				if (strcmp(password, pp->pw_passwd) == 0)
610 					break;
611 				warning("single-user login failed\n");
612 			}
613 		}
614 		endttyent();
615 		endpwent();
616 #endif /* SECURE */
617 
618 #ifdef DEBUGSHELL
619 		{
620 			char *cp = altshell;
621 			int num;
622 
623 #define	SHREQUEST \
624 	"Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
625 			(void)write(STDERR_FILENO,
626 			    SHREQUEST, sizeof(SHREQUEST) - 1);
627 			while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
628 			    num != 0 && *cp != '\n' && cp < &altshell[127])
629 					cp++;
630 			*cp = '\0';
631 			if (altshell[0] != '\0')
632 				shell = altshell;
633 		}
634 #endif /* DEBUGSHELL */
635 
636 		/*
637 		 * Unblock signals.
638 		 * We catch all the interesting ones,
639 		 * and those are reset to SIG_DFL on exec.
640 		 */
641 		sigemptyset(&mask);
642 		sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
643 
644 		/*
645 		 * Fire off a shell.
646 		 * If the default one doesn't work, try the Bourne shell.
647 		 */
648 		argv[0] = "-sh";
649 		argv[1] = 0;
650 		execv(shell, argv);
651 		emergency("can't exec %s for single user: %m", shell);
652 		execv(_PATH_BSHELL, argv);
653 		emergency("can't exec %s for single user: %m", _PATH_BSHELL);
654 		sleep(STALL_TIMEOUT);
655 		_exit(1);
656 	}
657 
658 	if (pid == -1) {
659 		/*
660 		 * We are seriously hosed.  Do our best.
661 		 */
662 		emergency("can't fork single-user shell, trying again");
663 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
664 			continue;
665 		return (state_func_t) single_user;
666 	}
667 
668 	requested_transition = 0;
669 	do {
670 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
671 			collect_child(wpid);
672 		if (wpid == -1) {
673 			if (errno == EINTR)
674 				continue;
675 			warning("wait for single-user shell failed: %m; restarting");
676 			return (state_func_t) single_user;
677 		}
678 		if (wpid == pid && WIFSTOPPED(status)) {
679 			warning("init: shell stopped, restarting\n");
680 			kill(pid, SIGCONT);
681 			wpid = -1;
682 		}
683 	} while (wpid != pid && !requested_transition);
684 
685 	if (requested_transition)
686 		return (state_func_t) requested_transition;
687 
688 	if (!WIFEXITED(status)) {
689 		if (WTERMSIG(status) == SIGKILL) {
690 			/*
691 			 *  reboot(8) killed shell?
692 			 */
693 			warning("single user shell terminated.");
694 			sleep(STALL_TIMEOUT);
695 			_exit(0);
696 		} else {
697 			warning("single user shell terminated, restarting");
698 			return (state_func_t) single_user;
699 		}
700 	}
701 
702 	runcom_mode = FASTBOOT;
703 	return (state_func_t) runcom;
704 }
705 
706 /*
707  * Run the system startup script.
708  */
709 state_func_t
710 runcom(void)
711 {
712 	pid_t pid, wpid;
713 	int status;
714 	char *argv[4];
715 	struct sigaction sa;
716 
717 	if ((pid = fork()) == 0) {
718 		sigemptyset(&sa.sa_mask);
719 		sa.sa_flags = 0;
720 		sa.sa_handler = SIG_IGN;
721 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
722 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
723 
724 		setctty(_PATH_CONSOLE);
725 
726 		argv[0] = "sh";
727 		argv[1] = _PATH_RUNCOM;
728 		argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
729 		argv[3] = 0;
730 
731 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
732 
733 #ifdef LOGIN_CAP
734 		setprocresources(RESOURCE_RC);
735 #endif
736 		execv(_PATH_BSHELL, argv);
737 		stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
738 		_exit(1);	/* force single user mode */
739 	}
740 
741 	if (pid == -1) {
742 		emergency("can't fork for %s on %s: %m",
743 			_PATH_BSHELL, _PATH_RUNCOM);
744 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
745 			continue;
746 		sleep(STALL_TIMEOUT);
747 		return (state_func_t) single_user;
748 	}
749 
750 	/*
751 	 * Copied from single_user().  This is a bit paranoid.
752 	 */
753 	requested_transition = 0;
754 	do {
755 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
756 			collect_child(wpid);
757 		if (wpid == -1) {
758 			if (requested_transition == death)
759 				return (state_func_t) death;
760 			if (errno == EINTR)
761 				continue;
762 			warning("wait for %s on %s failed: %m; going to single user mode",
763 				_PATH_BSHELL, _PATH_RUNCOM);
764 			return (state_func_t) single_user;
765 		}
766 		if (wpid == pid && WIFSTOPPED(status)) {
767 			warning("init: %s on %s stopped, restarting\n",
768 				_PATH_BSHELL, _PATH_RUNCOM);
769 			kill(pid, SIGCONT);
770 			wpid = -1;
771 		}
772 	} while (wpid != pid);
773 
774 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
775 	    requested_transition == catatonia) {
776 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
777 		sigset_t s;
778 
779 		sigfillset(&s);
780 		for (;;)
781 			sigsuspend(&s);
782 	}
783 
784 	if (!WIFEXITED(status)) {
785 		warning("%s on %s terminated abnormally, going to single user mode",
786 			_PATH_BSHELL, _PATH_RUNCOM);
787 		return (state_func_t) single_user;
788 	}
789 
790 	if (WEXITSTATUS(status))
791 		return (state_func_t) single_user;
792 
793 	runcom_mode = AUTOBOOT;		/* the default */
794 	/* NB: should send a message to the session logger to avoid blocking. */
795 	logwtmp("~", "reboot", "");
796 	return (state_func_t) read_ttys;
797 }
798 
799 /*
800  * Open the session database.
801  *
802  * NB: We could pass in the size here; is it necessary?
803  */
804 int
805 start_session_db(void)
806 {
807 	if (session_db && (*session_db->close)(session_db))
808 		emergency("session database close: %s", strerror(errno));
809 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
810 		emergency("session database open: %s", strerror(errno));
811 		return (1);
812 	}
813 	return (0);
814 
815 }
816 
817 /*
818  * Add a new login session.
819  */
820 void
821 add_session(session_t *sp)
822 {
823 	DBT key;
824 	DBT data;
825 
826 	key.data = &sp->se_process;
827 	key.size = sizeof sp->se_process;
828 	data.data = &sp;
829 	data.size = sizeof sp;
830 
831 	if ((*session_db->put)(session_db, &key, &data, 0))
832 		emergency("insert %d: %s", sp->se_process, strerror(errno));
833 }
834 
835 /*
836  * Delete an old login session.
837  */
838 void
839 del_session(session_t *sp)
840 {
841 	DBT key;
842 
843 	key.data = &sp->se_process;
844 	key.size = sizeof sp->se_process;
845 
846 	if ((*session_db->del)(session_db, &key, 0))
847 		emergency("delete %d: %s", sp->se_process, strerror(errno));
848 }
849 
850 /*
851  * Look up a login session by pid.
852  */
853 session_t *
854 find_session(pid_t pid)
855 {
856 	DBT key;
857 	DBT data;
858 	session_t *ret;
859 
860 	key.data = &pid;
861 	key.size = sizeof pid;
862 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
863 		return 0;
864 	bcopy(data.data, (char *)&ret, sizeof(ret));
865 	return ret;
866 }
867 
868 /*
869  * Construct an argument vector from a command line.
870  */
871 char **
872 construct_argv(char *command)
873 {
874 	char *strk (char *);
875 	int argc = 0;
876 	char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
877 						* sizeof (char *));
878 
879 	if ((argv[argc++] = strk(command)) == 0) {
880 		free(argv);
881 		return (NULL);
882 	}
883 	while ((argv[argc++] = strk((char *) 0)) != NULL)
884 		continue;
885 	return argv;
886 }
887 
888 /*
889  * Deallocate a session descriptor.
890  */
891 void
892 free_session(session_t *sp)
893 {
894 	free(sp->se_device);
895 	if (sp->se_getty) {
896 		free(sp->se_getty);
897 		free(sp->se_getty_argv_space);
898 		free(sp->se_getty_argv);
899 	}
900 	if (sp->se_window) {
901 		free(sp->se_window);
902 		free(sp->se_window_argv_space);
903 		free(sp->se_window_argv);
904 	}
905 	if (sp->se_type)
906 		free(sp->se_type);
907 	free(sp);
908 }
909 
910 /*
911  * Allocate a new session descriptor.
912  * Mark it SE_PRESENT.
913  */
914 session_t *
915 new_session(session_t *sprev, int session_index, struct ttyent *typ)
916 {
917 	session_t *sp;
918 	int fd;
919 
920 	if ((typ->ty_status & TTY_ON) == 0 ||
921 	    typ->ty_name == 0 ||
922 	    typ->ty_getty == 0)
923 		return 0;
924 
925 	sp = (session_t *) calloc(1, sizeof (session_t));
926 
927 	sp->se_index = session_index;
928 	sp->se_flags |= SE_PRESENT;
929 
930 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
931 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
932 
933 	/*
934 	 * Attempt to open the device, if we get "device not configured"
935 	 * then don't add the device to the session list.
936 	 */
937 	if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
938 		if (errno == ENXIO || errno == ENOENT) {
939 			free_session(sp);
940 			return (0);
941 		}
942 	} else
943 		close(fd);
944 
945 	if (setupargv(sp, typ) == 0) {
946 		free_session(sp);
947 		return (0);
948 	}
949 
950 	sp->se_next = 0;
951 	if (sprev == 0) {
952 		sessions = sp;
953 		sp->se_prev = 0;
954 	} else {
955 		sprev->se_next = sp;
956 		sp->se_prev = sprev;
957 	}
958 
959 	return sp;
960 }
961 
962 /*
963  * Calculate getty and if useful window argv vectors.
964  */
965 int
966 setupargv(session_t *sp, struct ttyent *typ)
967 {
968 
969 	if (sp->se_getty) {
970 		free(sp->se_getty);
971 		free(sp->se_getty_argv_space);
972 		free(sp->se_getty_argv);
973 	}
974 	sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
975 	(void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
976 	sp->se_getty_argv_space = strdup(sp->se_getty);
977 	sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
978 	if (sp->se_getty_argv == 0) {
979 		warning("can't parse getty for port %s", sp->se_device);
980 		free(sp->se_getty);
981 		free(sp->se_getty_argv_space);
982 		sp->se_getty = sp->se_getty_argv_space = 0;
983 		return (0);
984 	}
985 	if (sp->se_window) {
986 		free(sp->se_window);
987 		free(sp->se_window_argv_space);
988 		free(sp->se_window_argv);
989 	}
990 	sp->se_window = sp->se_window_argv_space = 0;
991 	sp->se_window_argv = 0;
992 	if (typ->ty_window) {
993 		sp->se_window = strdup(typ->ty_window);
994 		sp->se_window_argv_space = strdup(sp->se_window);
995 		sp->se_window_argv = construct_argv(sp->se_window_argv_space);
996 		if (sp->se_window_argv == 0) {
997 			warning("can't parse window for port %s",
998 				sp->se_device);
999 			free(sp->se_window_argv_space);
1000 			free(sp->se_window);
1001 			sp->se_window = sp->se_window_argv_space = 0;
1002 			return (0);
1003 		}
1004 	}
1005 	if (sp->se_type)
1006 		free(sp->se_type);
1007 	sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1008 	return (1);
1009 }
1010 
1011 /*
1012  * Walk the list of ttys and create sessions for each active line.
1013  */
1014 state_func_t
1015 read_ttys(void)
1016 {
1017 	int session_index = 0;
1018 	session_t *sp, *snext;
1019 	struct ttyent *typ;
1020 
1021 	/*
1022 	 * Destroy any previous session state.
1023 	 * There shouldn't be any, but just in case...
1024 	 */
1025 	for (sp = sessions; sp; sp = snext) {
1026 		if (sp->se_process)
1027 			clear_session_logs(sp);
1028 		snext = sp->se_next;
1029 		free_session(sp);
1030 	}
1031 	sessions = 0;
1032 	if (start_session_db())
1033 		return (state_func_t) single_user;
1034 
1035 	/*
1036 	 * Allocate a session entry for each active port.
1037 	 * Note that sp starts at 0.
1038 	 */
1039 	while ((typ = getttyent()) != NULL)
1040 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1041 			sp = snext;
1042 
1043 	endttyent();
1044 
1045 	return (state_func_t) multi_user;
1046 }
1047 
1048 /*
1049  * Start a window system running.
1050  */
1051 void
1052 start_window_system(session_t *sp)
1053 {
1054 	pid_t pid;
1055 	sigset_t mask;
1056 	char term[64], *env[2];
1057 
1058 	if ((pid = fork()) == -1) {
1059 		emergency("can't fork for window system on port %s: %m",
1060 			sp->se_device);
1061 		/* hope that getty fails and we can try again */
1062 		return;
1063 	}
1064 
1065 	if (pid)
1066 		return;
1067 
1068 	sigemptyset(&mask);
1069 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1070 
1071 	if (setsid() < 0)
1072 		emergency("setsid failed (window) %m");
1073 
1074 #ifdef LOGIN_CAP
1075 	setprocresources(RESOURCE_WINDOW);
1076 #endif
1077 	if (sp->se_type) {
1078 		/* Don't use malloc after fork */
1079 		strcpy(term, "TERM=");
1080 		strncat(term, sp->se_type, sizeof(term) - 6);
1081 		env[0] = term;
1082 		env[1] = 0;
1083 	}
1084 	else
1085 		env[0] = 0;
1086 	execve(sp->se_window_argv[0], sp->se_window_argv, env);
1087 	stall("can't exec window system '%s' for port %s: %m",
1088 		sp->se_window_argv[0], sp->se_device);
1089 	_exit(1);
1090 }
1091 
1092 /*
1093  * Start a login session running.
1094  */
1095 pid_t
1096 start_getty(session_t *sp)
1097 {
1098 	pid_t pid;
1099 	sigset_t mask;
1100 	time_t current_time = time((time_t *) 0);
1101 	int too_quick = 0;
1102 	char term[64], *env[2];
1103 
1104 	if (current_time >= sp->se_started &&
1105 	    current_time - sp->se_started < GETTY_SPACING) {
1106 		if (++sp->se_nspace > GETTY_NSPACE) {
1107 			sp->se_nspace = 0;
1108 			too_quick = 1;
1109 		}
1110 	} else
1111 		sp->se_nspace = 0;
1112 
1113 	/*
1114 	 * fork(), not vfork() -- we can't afford to block.
1115 	 */
1116 	if ((pid = fork()) == -1) {
1117 		emergency("can't fork for getty on port %s: %m", sp->se_device);
1118 		return -1;
1119 	}
1120 
1121 	if (pid)
1122 		return pid;
1123 
1124 	if (too_quick) {
1125 		warning("getty repeating too quickly on port %s, sleeping %d secs",
1126 			sp->se_device, GETTY_SLEEP);
1127 		sleep((unsigned) GETTY_SLEEP);
1128 	}
1129 
1130 	if (sp->se_window) {
1131 		start_window_system(sp);
1132 		sleep(WINDOW_WAIT);
1133 	}
1134 
1135 	sigemptyset(&mask);
1136 	sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1137 
1138 #ifdef LOGIN_CAP
1139 	setprocresources(RESOURCE_GETTY);
1140 #endif
1141 	if (sp->se_type) {
1142 		/* Don't use malloc after fork */
1143 		strcpy(term, "TERM=");
1144 		strncat(term, sp->se_type, sizeof(term) - 6);
1145 		env[0] = term;
1146 		env[1] = 0;
1147 	}
1148 	else
1149 		env[0] = 0;
1150 	execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1151 	stall("can't exec getty '%s' for port %s: %m",
1152 		sp->se_getty_argv[0], sp->se_device);
1153 	_exit(1);
1154 }
1155 
1156 /*
1157  * Collect exit status for a child.
1158  * If an exiting login, start a new login running.
1159  */
1160 void
1161 collect_child(pid_t pid)
1162 {
1163 	session_t *sp, *sprev, *snext;
1164 
1165 	if (! sessions)
1166 		return;
1167 
1168 	if (! (sp = find_session(pid)))
1169 		return;
1170 
1171 	clear_session_logs(sp);
1172 	del_session(sp);
1173 	sp->se_process = 0;
1174 
1175 	if (sp->se_flags & SE_SHUTDOWN) {
1176 		if ((sprev = sp->se_prev) != NULL)
1177 			sprev->se_next = sp->se_next;
1178 		else
1179 			sessions = sp->se_next;
1180 		if ((snext = sp->se_next) != NULL)
1181 			snext->se_prev = sp->se_prev;
1182 		free_session(sp);
1183 		return;
1184 	}
1185 
1186 	if ((pid = start_getty(sp)) == -1) {
1187 		/* serious trouble */
1188 		requested_transition = clean_ttys;
1189 		return;
1190 	}
1191 
1192 	sp->se_process = pid;
1193 	sp->se_started = time((time_t *) 0);
1194 	add_session(sp);
1195 }
1196 
1197 /*
1198  * Catch a signal and request a state transition.
1199  */
1200 void
1201 transition_handler(int sig)
1202 {
1203 
1204 	switch (sig) {
1205 	case SIGHUP:
1206 		requested_transition = clean_ttys;
1207 		break;
1208 	case SIGUSR2:
1209 		howto = RB_POWEROFF;
1210 	case SIGUSR1:
1211 		howto |= RB_HALT;
1212 	case SIGINT:
1213 		Reboot = TRUE;
1214 	case SIGTERM:
1215 		requested_transition = death;
1216 		break;
1217 	case SIGTSTP:
1218 		requested_transition = catatonia;
1219 		break;
1220 	default:
1221 		requested_transition = 0;
1222 		break;
1223 	}
1224 }
1225 
1226 /*
1227  * Take the system multiuser.
1228  */
1229 state_func_t
1230 multi_user(void)
1231 {
1232 	pid_t pid;
1233 	session_t *sp;
1234 
1235 	requested_transition = 0;
1236 
1237 	/*
1238 	 * If the administrator has not set the security level to -1
1239 	 * to indicate that the kernel should not run multiuser in secure
1240 	 * mode, and the run script has not set a higher level of security
1241 	 * than level 1, then put the kernel into secure mode.
1242 	 */
1243 	if (getsecuritylevel() == 0)
1244 		setsecuritylevel(1);
1245 
1246 	for (sp = sessions; sp; sp = sp->se_next) {
1247 		if (sp->se_process)
1248 			continue;
1249 		if ((pid = start_getty(sp)) == -1) {
1250 			/* serious trouble */
1251 			requested_transition = clean_ttys;
1252 			break;
1253 		}
1254 		sp->se_process = pid;
1255 		sp->se_started = time((time_t *) 0);
1256 		add_session(sp);
1257 	}
1258 
1259 	while (!requested_transition)
1260 		if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1261 			collect_child(pid);
1262 
1263 	return (state_func_t) requested_transition;
1264 }
1265 
1266 /*
1267  * This is an (n*2)+(n^2) algorithm.  We hope it isn't run often...
1268  */
1269 state_func_t
1270 clean_ttys(void)
1271 {
1272 	session_t *sp, *sprev;
1273 	struct ttyent *typ;
1274 	int session_index = 0;
1275 	int devlen;
1276 	char *old_getty, *old_window, *old_type;
1277 
1278 	/*
1279 	 * mark all sessions for death, (!SE_PRESENT)
1280 	 * as we find or create new ones they'll be marked as keepers,
1281 	 * we'll later nuke all the ones not found in /etc/ttys
1282 	 */
1283 	for (sp = sessions; sp != NULL; sp = sp->se_next)
1284 		sp->se_flags &= ~SE_PRESENT;
1285 
1286 	devlen = sizeof(_PATH_DEV) - 1;
1287 	while ((typ = getttyent()) != NULL) {
1288 		++session_index;
1289 
1290 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1291 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1292 				break;
1293 
1294 		if (sp) {
1295 			/* we want this one to live */
1296 			sp->se_flags |= SE_PRESENT;
1297 			if (sp->se_index != session_index) {
1298 				warning("port %s changed utmp index from %d to %d",
1299 				       sp->se_device, sp->se_index,
1300 				       session_index);
1301 				sp->se_index = session_index;
1302 			}
1303 			if ((typ->ty_status & TTY_ON) == 0 ||
1304 			    typ->ty_getty == 0) {
1305 				sp->se_flags |= SE_SHUTDOWN;
1306 				kill(sp->se_process, SIGHUP);
1307 				continue;
1308 			}
1309 			sp->se_flags &= ~SE_SHUTDOWN;
1310 			old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1311 			old_window = sp->se_window ? strdup(sp->se_window) : 0;
1312 			old_type = sp->se_type ? strdup(sp->se_type) : 0;
1313 			if (setupargv(sp, typ) == 0) {
1314 				warning("can't parse getty for port %s",
1315 					sp->se_device);
1316 				sp->se_flags |= SE_SHUTDOWN;
1317 				kill(sp->se_process, SIGHUP);
1318 			}
1319 			else if (   !old_getty
1320 				 || (!old_type && sp->se_type)
1321 				 || (old_type && !sp->se_type)
1322 				 || (!old_window && sp->se_window)
1323 				 || (old_window && !sp->se_window)
1324 				 || (strcmp(old_getty, sp->se_getty) != 0)
1325 				 || (old_window && strcmp(old_window, sp->se_window) != 0)
1326 				 || (old_type && strcmp(old_type, sp->se_type) != 0)
1327 				) {
1328 				/* Don't set SE_SHUTDOWN here */
1329 				sp->se_nspace = 0;
1330 				sp->se_started = 0;
1331 				kill(sp->se_process, SIGHUP);
1332 			}
1333 			if (old_getty)
1334 				free(old_getty);
1335 			if (old_window)
1336 				free(old_window);
1337 			if (old_type)
1338 				free(old_type);
1339 			continue;
1340 		}
1341 
1342 		new_session(sprev, session_index, typ);
1343 	}
1344 
1345 	endttyent();
1346 
1347 	/*
1348 	 * sweep through and kill all deleted sessions
1349 	 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1350 	 */
1351 	for (sp = sessions; sp != NULL; sp = sp->se_next) {
1352 		if ((sp->se_flags & SE_PRESENT) == 0) {
1353 			sp->se_flags |= SE_SHUTDOWN;
1354 			kill(sp->se_process, SIGHUP);
1355 		}
1356 	}
1357 
1358 	return (state_func_t) multi_user;
1359 }
1360 
1361 /*
1362  * Block further logins.
1363  */
1364 state_func_t
1365 catatonia(void)
1366 {
1367 	session_t *sp;
1368 
1369 	for (sp = sessions; sp; sp = sp->se_next)
1370 		sp->se_flags |= SE_SHUTDOWN;
1371 
1372 	return (state_func_t) multi_user;
1373 }
1374 
1375 /*
1376  * Note SIGALRM.
1377  */
1378 void
1379 alrm_handler(int sig)
1380 {
1381 	(void)sig;
1382 	clang = 1;
1383 }
1384 
1385 /*
1386  * Bring the system down to single user.
1387  */
1388 state_func_t
1389 death(void)
1390 {
1391 	session_t *sp;
1392 	int i;
1393 	pid_t pid;
1394 	static const int death_sigs[2] = { SIGTERM, SIGKILL };
1395 
1396 	/* NB: should send a message to the session logger to avoid blocking. */
1397 	logwtmp("~", "shutdown", "");
1398 
1399 	for (sp = sessions; sp; sp = sp->se_next) {
1400 		sp->se_flags |= SE_SHUTDOWN;
1401 		kill(sp->se_process, SIGHUP);
1402 	}
1403 
1404 	/* Try to run the rc.shutdown script within a period of time */
1405 	(void) runshutdown();
1406 
1407 	for (i = 0; i < 2; ++i) {
1408 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1409 			return (state_func_t) single_user;
1410 
1411 		clang = 0;
1412 		alarm(DEATH_WATCH);
1413 		do
1414 			if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1415 				collect_child(pid);
1416 		while (clang == 0 && errno != ECHILD);
1417 
1418 		if (errno == ECHILD)
1419 			return (state_func_t) single_user;
1420 	}
1421 
1422 	warning("some processes would not die; ps axl advised");
1423 
1424 	return (state_func_t) single_user;
1425 }
1426 
1427 /*
1428  * Run the system shutdown script.
1429  *
1430  * Exit codes:      XXX I should document more
1431  * -2       shutdown script terminated abnormally
1432  * -1       fatal error - can't run script
1433  * 0        good.
1434  * >0       some error (exit code)
1435  */
1436 int
1437 runshutdown(void)
1438 {
1439 	pid_t pid, wpid;
1440 	int status;
1441 	int shutdowntimeout;
1442 	size_t len;
1443 	char *argv[4];
1444 	struct sigaction sa;
1445 	struct stat sb;
1446 
1447 	/*
1448 	 * rc.shutdown is optional, so to prevent any unnecessary
1449 	 * complaints from the shell we simply don't run it if the
1450 	 * file does not exist. If the stat() here fails for other
1451 	 * reasons, we'll let the shell complain.
1452 	 */
1453 	if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1454 		return 0;
1455 
1456 	if ((pid = fork()) == 0) {
1457 		int	fd;
1458 
1459 		/* Assume that init already grab console as ctty before */
1460 
1461 		sigemptyset(&sa.sa_mask);
1462 		sa.sa_flags = 0;
1463 		sa.sa_handler = SIG_IGN;
1464 		(void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1465 		(void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
1466 
1467 		if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1468 		    warning("can't open %s: %m", _PATH_CONSOLE);
1469 		else {
1470 		    (void) dup2(fd, 0);
1471 		    (void) dup2(fd, 1);
1472 		    (void) dup2(fd, 2);
1473 		    if (fd > 2)
1474 			close(fd);
1475 		}
1476 
1477 		/*
1478 		 * Run the shutdown script.
1479 		 */
1480 		argv[0] = "sh";
1481 		argv[1] = _PATH_RUNDOWN;
1482 		if (Reboot)
1483 			argv[2] = "reboot";
1484 		else
1485 			argv[2] = "single";
1486 		argv[3] = 0;
1487 
1488 		sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1489 
1490 #ifdef LOGIN_CAP
1491 		setprocresources(RESOURCE_RC);
1492 #endif
1493 		execv(_PATH_BSHELL, argv);
1494 		warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1495 		_exit(1);	/* force single user mode */
1496 	}
1497 
1498 	if (pid == -1) {
1499 		emergency("can't fork for %s on %s: %m",
1500 			_PATH_BSHELL, _PATH_RUNDOWN);
1501 		while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1502 			continue;
1503 		sleep(STALL_TIMEOUT);
1504 		return -1;
1505 	}
1506 
1507 	len = sizeof(shutdowntimeout);
1508 	if (sysctlbyname("kern.shutdown_timeout",
1509 			 &shutdowntimeout,
1510 			 &len, NULL, 0) == -1 || shutdowntimeout < 2)
1511 	    shutdowntimeout = DEATH_SCRIPT;
1512 	alarm(shutdowntimeout);
1513 	clang = 0;
1514 	/*
1515 	 * Copied from single_user().  This is a bit paranoid.
1516 	 * Use the same ALRM handler.
1517 	 */
1518 	do {
1519 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1520 			collect_child(wpid);
1521 		if (clang == 1) {
1522 			/* we were waiting for the sub-shell */
1523 			kill(wpid, SIGTERM);
1524 			warning("timeout expired for %s on %s: %m; going to single user mode",
1525 				_PATH_BSHELL, _PATH_RUNDOWN);
1526 			return -1;
1527 		}
1528 		if (wpid == -1) {
1529 			if (errno == EINTR)
1530 				continue;
1531 			warning("wait for %s on %s failed: %m; going to single user mode",
1532 				_PATH_BSHELL, _PATH_RUNDOWN);
1533 			return -1;
1534 		}
1535 		if (wpid == pid && WIFSTOPPED(status)) {
1536 			warning("init: %s on %s stopped, restarting\n",
1537 				_PATH_BSHELL, _PATH_RUNDOWN);
1538 			kill(pid, SIGCONT);
1539 			wpid = -1;
1540 		}
1541 	} while (wpid != pid && !clang);
1542 
1543 	/* Turn off the alarm */
1544 	alarm(0);
1545 
1546 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1547 	    requested_transition == catatonia) {
1548 		/*
1549 		 * /etc/rc.shutdown executed /sbin/reboot;
1550 		 * wait for the end quietly
1551 		 */
1552 		sigset_t s;
1553 
1554 		sigfillset(&s);
1555 		for (;;)
1556 			sigsuspend(&s);
1557 	}
1558 
1559 	if (!WIFEXITED(status)) {
1560 		warning("%s on %s terminated abnormally, going to single user mode",
1561 			_PATH_BSHELL, _PATH_RUNDOWN);
1562 		return -2;
1563 	}
1564 
1565 	if ((status = WEXITSTATUS(status)) != 0)
1566 		warning("%s returned status %d", _PATH_RUNDOWN, status);
1567 
1568 	return status;
1569 }
1570 
1571 char *
1572 strk (char *p)
1573 {
1574     static char *t;
1575     char *q;
1576     int c;
1577 
1578     if (p)
1579 	t = p;
1580     if (!t)
1581 	return 0;
1582 
1583     c = *t;
1584     while (c == ' ' || c == '\t' )
1585 	c = *++t;
1586     if (!c) {
1587 	t = 0;
1588 	return 0;
1589     }
1590     q = t;
1591     if (c == '\'') {
1592 	c = *++t;
1593 	q = t;
1594 	while (c && c != '\'')
1595 	    c = *++t;
1596 	if (!c)  /* unterminated string */
1597 	    q = t = 0;
1598 	else
1599 	    *t++ = 0;
1600     } else {
1601 	while (c && c != ' ' && c != '\t' )
1602 	    c = *++t;
1603 	*t++ = 0;
1604 	if (!c)
1605 	    t = 0;
1606     }
1607     return q;
1608 }
1609 
1610 #ifdef LOGIN_CAP
1611 void
1612 setprocresources(const char *cname)
1613 {
1614 	login_cap_t *lc;
1615 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1616 		setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1617 		login_close(lc);
1618 	}
1619 }
1620 #endif
1621