xref: /netbsd-src/sbin/init/init.c (revision 1ca06f9c9235889e2ff6dc77279d01d151d70a9a)
1 /*	$NetBSD: init.c,v 1.99 2009/11/22 18:40:26 mbalmer Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Donn Seeley at Berkeley Software Design, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\
38  The Regents of the University of California.  All rights reserved.");
39 #endif /* not lint */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)init.c	8.2 (Berkeley) 4/28/95";
44 #else
45 __RCSID("$NetBSD: init.c,v 1.99 2009/11/22 18:40:26 mbalmer Exp $");
46 #endif
47 #endif /* not lint */
48 
49 #include <sys/param.h>
50 #include <sys/sysctl.h>
51 #include <sys/wait.h>
52 #include <sys/mman.h>
53 #include <sys/stat.h>
54 #include <sys/mount.h>
55 #include <machine/cpu.h>
56 
57 #include <db.h>
58 #include <errno.h>
59 #include <fcntl.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 <util.h>
69 #include <paths.h>
70 #include <err.h>
71 
72 #include <stdarg.h>
73 
74 #ifdef SECURE
75 #include <pwd.h>
76 #endif
77 
78 #include "pathnames.h"
79 
80 #define XSTR(x) #x
81 #define STR(x) XSTR(x)
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	WINDOW_WAIT		 3	/* wait N secs after starting window */
89 #define	STALL_TIMEOUT		30	/* wait N secs after warning */
90 #define	DEATH_WATCH		10	/* wait N secs for procs to die */
91 
92 const struct timespec dtrtime = {.tv_sec = 0, .tv_nsec = 250000};
93 
94 #if defined(RESCUEDIR)
95 #define	INIT_BSHELL	RESCUEDIR "/sh"
96 #define	INIT_MOUNT_MFS	RESCUEDIR "/mount_mfs"
97 #define	INIT_PATH	RESCUEDIR ":" _PATH_STDPATH
98 #else
99 #define	INIT_BSHELL	_PATH_BSHELL
100 #define	INIT_MOUNT_MFS	"/sbin/mount_mfs"
101 #define	INIT_PATH	_PATH_STDPATH
102 #endif
103 
104 int main(int, char *[]);
105 
106 void handle(sig_t, ...);
107 void delset(sigset_t *, ...);
108 
109 void stall(const char *, ...)
110     __attribute__((__format__(__printf__,1,2)));
111 void warning(const char *, ...)
112     __attribute__((__format__(__printf__,1,2)));
113 void emergency(const char *, ...)
114     __attribute__((__format__(__printf__,1,2)));
115 void disaster(int);
116 void badsys(int);
117 
118 /*
119  * We really need a recursive typedef...
120  * The following at least guarantees that the return type of (*state_t)()
121  * is sufficiently wide to hold a function pointer.
122  */
123 typedef long (*state_func_t)(void);
124 typedef state_func_t (*state_t)(void);
125 
126 #define	DEATH		'd'
127 #define	SINGLE_USER	's'
128 #define	RUNCOM		'r'
129 #define	READ_TTYS	't'
130 #define	MULTI_USER	'm'
131 #define	CLEAN_TTYS	'T'
132 #define	CATATONIA	'c'
133 
134 state_func_t single_user(void);
135 state_func_t runcom(void);
136 state_func_t read_ttys(void);
137 state_func_t multi_user(void);
138 state_func_t clean_ttys(void);
139 state_func_t catatonia(void);
140 state_func_t death(void);
141 
142 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
143 
144 void transition(state_t);
145 void setctty(const char *);
146 
147 typedef struct init_session {
148 	int	se_index;		/* index of entry in ttys file */
149 	pid_t	se_process;		/* controlling process */
150 	struct timeval	se_started;	/* used to avoid thrashing */
151 	int	se_flags;		/* status of session */
152 #define	SE_SHUTDOWN	0x1		/* session won't be restarted */
153 #define	SE_PRESENT	0x2		/* session is in /etc/ttys */
154 	char	*se_device;		/* filename of port */
155 	char	*se_getty;		/* what to run on that port */
156 	char	**se_getty_argv;	/* pre-parsed argument array */
157 	char	*se_window;		/* window system (started only once) */
158 	char	**se_window_argv;	/* pre-parsed argument array */
159 	struct	init_session *se_prev;
160 	struct	init_session *se_next;
161 } session_t;
162 
163 void free_session(session_t *);
164 session_t *new_session(session_t *, int, struct ttyent *);
165 session_t *sessions;
166 
167 char **construct_argv(char *);
168 void start_window_system(session_t *);
169 void collect_child(pid_t, int);
170 pid_t start_getty(session_t *);
171 void transition_handler(int);
172 void alrm_handler(int);
173 void setsecuritylevel(int);
174 int getsecuritylevel(void);
175 int setupargv(session_t *, struct ttyent *);
176 int clang;
177 
178 int start_session_db(void);
179 void add_session(session_t *);
180 void del_session(session_t *);
181 session_t *find_session(pid_t);
182 DB *session_db;
183 
184 int do_setttyent(void);
185 
186 #ifndef LETS_GET_SMALL
187 state_t requested_transition = runcom;
188 
189 void clear_session_logs(session_t *, int);
190 state_func_t runetcrc(int);
191 #ifdef SUPPORT_UTMPX
192 static struct timeval boot_time;
193 state_t current_state = death;
194 static void session_utmpx(const session_t *, int);
195 static void make_utmpx(const char *, const char *, int, pid_t,
196     const struct timeval *, int);
197 static char get_runlevel(const state_t);
198 static void utmpx_set_runlevel(char, char);
199 #endif
200 
201 #ifdef CHROOT
202 int did_multiuser_chroot = 0;
203 char rootdir[PATH_MAX];
204 int shouldchroot(void);
205 int createsysctlnode(void);
206 #endif /* CHROOT */
207 
208 #else /* LETS_GET_SMALL */
209 state_t requested_transition = single_user;
210 #endif /* !LETS_GET_SMALL */
211 
212 #ifdef MFS_DEV_IF_NO_CONSOLE
213 
214 static int mfs_dev(void);
215 
216 #endif
217 
218 /*
219  * The mother of all processes.
220  */
221 int
222 main(int argc, char **argv)
223 {
224 	struct sigaction sa;
225 	sigset_t mask;
226 #ifndef LETS_GET_SMALL
227 	int c;
228 
229 #ifdef SUPPORT_UTMPX
230 	(void)gettimeofday(&boot_time, NULL);
231 #endif /* SUPPORT_UTMPX */
232 
233 	/* Dispose of random users. */
234 	if (getuid() != 0) {
235 		errno = EPERM;
236 		err(1, NULL);
237 	}
238 
239 	/* System V users like to reexec init. */
240 	if (getpid() != 1)
241 		errx(1, "already running");
242 #endif
243 
244 	/*
245 	 * Create an initial session.
246 	 */
247 	if (setsid() < 0)
248 		warn("initial setsid() failed");
249 
250 	/*
251 	 * Establish an initial user so that programs running
252 	 * single user do not freak out and die (like passwd).
253 	 */
254 	if (setlogin("root") < 0)
255 		warn("setlogin() failed");
256 
257 
258 #ifdef MFS_DEV_IF_NO_CONSOLE
259 	if (mfs_dev() == -1)
260 		requested_transition = single_user;
261 #endif
262 
263 #ifndef LETS_GET_SMALL
264 	/*
265 	 * Note that this does NOT open a file...
266 	 * Does 'init' deserve its own facility number?
267 	 */
268 	openlog("init", LOG_CONS, LOG_AUTH);
269 #endif /* LETS_GET_SMALL */
270 
271 
272 #ifndef LETS_GET_SMALL
273 	/*
274 	 * This code assumes that we always get arguments through flags,
275 	 * never through bits set in some random machine register.
276 	 */
277 	while ((c = getopt(argc, argv, "sf")) != -1)
278 		switch (c) {
279 		case 's':
280 			requested_transition = single_user;
281 			break;
282 		case 'f':
283 			runcom_mode = FASTBOOT;
284 			break;
285 		default:
286 			warning("unrecognized flag `%c'", c);
287 			break;
288 		}
289 
290 	if (optind != argc)
291 		warning("ignoring excess arguments");
292 #else /* LETS_GET_SMALL */
293 	requested_transition = single_user;
294 #endif /* LETS_GET_SMALL */
295 
296 	/*
297 	 * We catch or block signals rather than ignore them,
298 	 * so that they get reset on exec.
299 	 */
300 	handle(badsys, SIGSYS, 0);
301 	handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
302 	       SIGBUS, SIGXCPU, SIGXFSZ, 0);
303 	handle(transition_handler, SIGHUP, SIGTERM, SIGTSTP, 0);
304 	handle(alrm_handler, SIGALRM, 0);
305 	(void)sigfillset(&mask);
306 	delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
307 	    SIGXCPU, SIGXFSZ, SIGHUP, SIGTERM, SIGTSTP, SIGALRM, 0);
308 	(void)sigprocmask(SIG_SETMASK, &mask, NULL);
309 	(void)sigemptyset(&sa.sa_mask);
310 	sa.sa_flags = 0;
311 	sa.sa_handler = SIG_IGN;
312 	(void)sigaction(SIGTTIN, &sa, NULL);
313 	(void)sigaction(SIGTTOU, &sa, NULL);
314 
315 	/*
316 	 * Paranoia.
317 	 */
318 	(void)close(0);
319 	(void)close(1);
320 	(void)close(2);
321 
322 #if !defined(LETS_GET_SMALL) && defined(CHROOT)
323 	/* Create "init.root" sysctl node. */
324 	(void)createsysctlnode();
325 #endif /* !LETS_GET_SMALL && CHROOT*/
326 
327 	/*
328 	 * Start the state machine.
329 	 */
330 	transition(requested_transition);
331 
332 	/*
333 	 * Should never reach here.
334 	 */
335 	return 1;
336 }
337 
338 /*
339  * Associate a function with a signal handler.
340  */
341 void
342 handle(sig_t handler, ...)
343 {
344 	int sig;
345 	struct sigaction sa;
346 	sigset_t mask_everything;
347 	va_list ap;
348 
349 	va_start(ap, handler);
350 
351 	sa.sa_handler = handler;
352 	(void)sigfillset(&mask_everything);
353 
354 	while ((sig = va_arg(ap, int)) != 0) {
355 		sa.sa_mask = mask_everything;
356 		/* XXX SA_RESTART? */
357 		sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
358 		(void)sigaction(sig, &sa, NULL);
359 	}
360 	va_end(ap);
361 }
362 
363 /*
364  * Delete a set of signals from a mask.
365  */
366 void
367 delset(sigset_t *maskp, ...)
368 {
369 	int sig;
370 	va_list ap;
371 
372 	va_start(ap, maskp);
373 
374 	while ((sig = va_arg(ap, int)) != 0)
375 		(void)sigdelset(maskp, sig);
376 	va_end(ap);
377 }
378 
379 #if 0	/* Enable to get error messages from init ! */
380 #define vsyslog(level, fmt, ap) print_console(level, fmt, ap)
381 #define closelog()
382 
383 static void
384 print_console(int level, const char *message, va_list ap)
385 {
386 	/*
387 	 * XXX: syslog seems to just plain not work in console-only
388 	 * XXX: situation... that should be fixed.  Let's leave this
389 	 * XXX: note + code here in case someone gets in trouble and
390 	 * XXX: wants to debug. -- Jachym Holecek <freza@liberouter.org>
391 	 */
392 	char errbuf[1024];
393 	int fd, len;
394 
395 	/* We can't do anything on errors, anyway... */
396 	fd = open(_PATH_CONSOLE, O_WRONLY);
397 	if (fd == -1)
398 		return ;
399 
400 	/* %m will get lost... */
401 	len = vsnprintf(errbuf, sizeof(errbuf), message, ap);
402 	(void)write(fd, (void *)errbuf, len);
403 	(void)close(fd);
404 }
405 #endif
406 
407 /*
408  * Log a message and sleep for a while (to give someone an opportunity
409  * to read it and to save log or hardcopy output if the problem is chronic).
410  * NB: should send a message to the session logger to avoid blocking.
411  */
412 void
413 stall(const char *message, ...)
414 {
415 	va_list ap;
416 
417 	va_start(ap, message);
418 	vsyslog(LOG_ALERT, message, ap);
419 	va_end(ap);
420 	closelog();
421 	(void)sleep(STALL_TIMEOUT);
422 }
423 
424 /*
425  * Like stall(), but doesn't sleep.
426  * If cpp had variadic macros, the two functions could be #defines for another.
427  * NB: should send a message to the session logger to avoid blocking.
428  */
429 void
430 warning(const char *message, ...)
431 {
432 	va_list ap;
433 
434 	va_start(ap, message);
435 	vsyslog(LOG_ALERT, message, ap);
436 	va_end(ap);
437 	closelog();
438 }
439 
440 /*
441  * Log an emergency message.
442  * NB: should send a message to the session logger to avoid blocking.
443  */
444 void
445 emergency(const char *message, ...)
446 {
447 	va_list ap;
448 
449 	va_start(ap, message);
450 	vsyslog(LOG_EMERG, message, ap);
451 	va_end(ap);
452 	closelog();
453 }
454 
455 /*
456  * Catch a SIGSYS signal.
457  *
458  * These may arise if a system does not support sysctl.
459  * We tolerate up to 25 of these, then throw in the towel.
460  */
461 void
462 badsys(int sig)
463 {
464 	static int badcount = 0;
465 
466 	if (badcount++ < 25)
467 		return;
468 	disaster(sig);
469 }
470 
471 /*
472  * Catch an unexpected signal.
473  */
474 void
475 disaster(int sig)
476 {
477 
478 	emergency("fatal signal: %s", strsignal(sig));
479 	(void)sleep(STALL_TIMEOUT);
480 	_exit(sig);		/* reboot */
481 }
482 
483 /*
484  * Get the security level of the kernel.
485  */
486 int
487 getsecuritylevel(void)
488 {
489 #ifdef KERN_SECURELVL
490 	int name[2], curlevel;
491 	size_t len;
492 
493 	name[0] = CTL_KERN;
494 	name[1] = KERN_SECURELVL;
495 	len = sizeof curlevel;
496 	if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
497 		emergency("cannot get kernel security level: %m");
498 		return -1;
499 	}
500 	return curlevel;
501 #else
502 	return -1;
503 #endif
504 }
505 
506 /*
507  * Set the security level of the kernel.
508  */
509 void
510 setsecuritylevel(int newlevel)
511 {
512 #ifdef KERN_SECURELVL
513 	int name[2], curlevel;
514 
515 	curlevel = getsecuritylevel();
516 	if (newlevel == curlevel)
517 		return;
518 	name[0] = CTL_KERN;
519 	name[1] = KERN_SECURELVL;
520 	if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
521 		emergency("cannot change kernel security level from"
522 		    " %d to %d: %m", curlevel, newlevel);
523 		return;
524 	}
525 #ifdef SECURE
526 	warning("kernel security level changed from %d to %d",
527 	    curlevel, newlevel);
528 #endif
529 #endif
530 }
531 
532 /*
533  * Change states in the finite state machine.
534  * The initial state is passed as an argument.
535  */
536 void
537 transition(state_t s)
538 {
539 
540 	if (s == NULL)
541 		return;
542 	for (;;) {
543 #ifdef SUPPORT_UTMPX
544 #ifndef LETS_GET_SMALL
545 		utmpx_set_runlevel(get_runlevel(current_state),
546 		    get_runlevel(s));
547 		current_state = s;
548 #endif
549 #endif
550 		s = (state_t)(*s)();
551 	}
552 }
553 
554 #ifndef LETS_GET_SMALL
555 /*
556  * Close out the accounting files for a login session.
557  * NB: should send a message to the session logger to avoid blocking.
558  */
559 void
560 clear_session_logs(session_t *sp, int status)
561 {
562 #if defined(SUPPORT_UTMP) || defined(SUPPORT_UTMPX)
563 	char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
564 #endif
565 
566 #ifdef SUPPORT_UTMPX
567 	if (logoutx(line, status, DEAD_PROCESS))
568 		logwtmpx(line, "", "", status, DEAD_PROCESS);
569 #endif
570 #ifdef SUPPORT_UTMP
571 	if (logout(line))
572 		logwtmp(line, "", "");
573 #endif
574 }
575 #endif
576 
577 /*
578  * Start a session and allocate a controlling terminal.
579  * Only called by children of init after forking.
580  */
581 void
582 setctty(const char *name)
583 {
584 	int fd;
585 
586 	(void)revoke(name);
587 	(void)nanosleep(&dtrtime, NULL);	/* leave DTR low for a bit */
588 	if ((fd = open(name, O_RDWR)) == -1) {
589 		stall("can't open %s: %m", name);
590 		_exit(1);
591 	}
592 	if (login_tty(fd) == -1) {
593 		stall("can't get %s for controlling terminal: %m", name);
594 		_exit(2);
595 	}
596 }
597 
598 /*
599  * Bring the system up single user.
600  */
601 state_func_t
602 single_user(void)
603 {
604 	pid_t pid, wpid;
605 	int status;
606 	int from_securitylevel;
607 	sigset_t mask;
608 	struct sigaction sa, satstp, sahup;
609 #ifdef ALTSHELL
610 	const char *shell = INIT_BSHELL;
611 #endif
612 	const char *argv[2];
613 #ifdef SECURE
614 	struct ttyent *typ;
615 	struct passwd *pp;
616 	char *clear, *password;
617 #endif
618 #ifdef ALTSHELL
619 	char altshell[128];
620 #endif /* ALTSHELL */
621 
622 #if !defined(LETS_GET_SMALL) && defined(CHROOT)
623 	/* Clear previous idea, just in case. */
624 	did_multiuser_chroot = 0;
625 #endif /* !LETS_GET_SMALL && CHROOT */
626 
627 	/*
628 	 * If the kernel is in secure mode, downgrade it to insecure mode.
629 	 */
630 	from_securitylevel = getsecuritylevel();
631 	if (from_securitylevel > 0)
632 		setsecuritylevel(0);
633 
634 	(void)sigemptyset(&sa.sa_mask);
635 	sa.sa_flags = 0;
636 	sa.sa_handler = SIG_IGN;
637 	(void)sigaction(SIGTSTP, &sa, &satstp);
638 	(void)sigaction(SIGHUP, &sa, &sahup);
639 	if ((pid = fork()) == 0) {
640 		/*
641 		 * Start the single user session.
642 		 */
643 		if (access(_PATH_CONSTTY, F_OK) == 0)
644 			setctty(_PATH_CONSTTY);
645 		else
646 			setctty(_PATH_CONSOLE);
647 
648 #ifdef SECURE
649 		/*
650 		 * Check the root password.
651 		 * We don't care if the console is 'on' by default;
652 		 * it's the only tty that can be 'off' and 'secure'.
653 		 */
654 		typ = getttynam("console");
655 		pp = getpwnam("root");
656 		if (typ && (from_securitylevel >=2 || (typ->ty_status
657 		    & TTY_SECURE) == 0) && pp && *pp->pw_passwd != '\0') {
658 			(void)fprintf(stderr,
659 			    "Enter root password, or ^D to go multi-user\n");
660 			for (;;) {
661 				clear = getpass("Password:");
662 				if (clear == 0 || *clear == '\0')
663 					_exit(0);
664 				password = crypt(clear, pp->pw_passwd);
665 				(void)memset(clear, 0, _PASSWORD_LEN);
666 				if (strcmp(password, pp->pw_passwd) == 0)
667 					break;
668 				warning("single-user login failed");
669 			}
670 		}
671 		(void)endttyent();
672 		endpwent();
673 #endif /* SECURE */
674 
675 #ifdef ALTSHELL
676 		(void)fprintf(stderr,
677 		    "Enter pathname of shell or RETURN for %s: ", shell);
678 		if (fgets(altshell, sizeof(altshell), stdin) == NULL) {
679 			altshell[0] = '\0';
680 		} else {
681 			/* nuke \n */
682 			char *p;
683 
684 			if ((p = strchr(altshell, '\n')) != NULL)
685 				*p = '\0';
686 		}
687 
688 		if (altshell[0])
689 			shell = altshell;
690 #endif /* ALTSHELL */
691 
692 		/*
693 		 * Unblock signals.
694 		 * We catch all the interesting ones,
695 		 * and those are reset to SIG_DFL on exec.
696 		 */
697 		(void)sigemptyset(&mask);
698 		(void)sigprocmask(SIG_SETMASK, &mask, NULL);
699 
700 		/*
701 		 * Fire off a shell.
702 		 * If the default one doesn't work, try the Bourne shell.
703 		 */
704 		argv[0] = "-sh";
705 		argv[1] = 0;
706 		(void)setenv("PATH", INIT_PATH, 1);
707 #ifdef ALTSHELL
708 		if (altshell[0])
709 			argv[0] = altshell;
710 		(void)execv(shell, __UNCONST(argv));
711 		emergency("can't exec `%s' for single user: %m", shell);
712 		argv[0] = "-sh";
713 #endif /* ALTSHELL */
714 		(void)execv(INIT_BSHELL, __UNCONST(argv));
715 		emergency("can't exec `%s' for single user: %m", INIT_BSHELL);
716 		(void)sleep(STALL_TIMEOUT);
717 		_exit(3);
718 	}
719 
720 	if (pid == -1) {
721 		/*
722 		 * We are seriously hosed.  Do our best.
723 		 */
724 		emergency("can't fork single-user shell: %m, trying again");
725 		while (waitpid(-1, NULL, WNOHANG) > 0)
726 			continue;
727 		(void)sigaction(SIGTSTP, &satstp, NULL);
728 		(void)sigaction(SIGHUP, &sahup, NULL);
729 		return (state_func_t)single_user;
730 	}
731 
732 	requested_transition = 0;
733 	do {
734 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
735 			collect_child(wpid, status);
736 		if (wpid == -1) {
737 			if (errno == EINTR)
738 				continue;
739 			warning("wait for single-user shell failed: %m; "
740 			    "restarting");
741 			return (state_func_t)single_user;
742 		}
743 		if (wpid == pid && WIFSTOPPED(status)) {
744 			warning("shell stopped, restarting");
745 			(void)kill(pid, SIGCONT);
746 			wpid = -1;
747 		}
748 	} while (wpid != pid && !requested_transition);
749 
750 	if (requested_transition) {
751 		(void)sigaction(SIGTSTP, &satstp, NULL);
752 		(void)sigaction(SIGHUP, &sahup, NULL);
753 		return (state_func_t)requested_transition;
754 	}
755 
756 	if (WIFSIGNALED(status)) {
757 		if (WTERMSIG(status) == SIGKILL) {
758 			/* executed /sbin/reboot; wait for the end quietly */
759 			sigset_t s;
760 
761 			(void)sigfillset(&s);
762 			for (;;)
763 				(void)sigsuspend(&s);
764 		} else {
765 			warning("single user shell terminated (%x), restarting",
766 				status);
767 			(void)sigaction(SIGTSTP, &satstp, NULL);
768 			(void)sigaction(SIGHUP, &sahup, NULL);
769 			return (state_func_t)single_user;
770 		}
771 	}
772 
773 	runcom_mode = FASTBOOT;
774 	(void)sigaction(SIGTSTP, &satstp, NULL);
775 	(void)sigaction(SIGHUP, &sahup, NULL);
776 #ifndef LETS_GET_SMALL
777 	return (state_func_t)runcom;
778 #else /* LETS_GET_SMALL */
779 	return (state_func_t)single_user;
780 #endif /* LETS_GET_SMALL */
781 }
782 
783 #ifndef LETS_GET_SMALL
784 
785 /* ARGSUSED */
786 state_func_t
787 runetcrc(int trychroot)
788 {
789 	pid_t pid, wpid;
790 	int status;
791 	const char *argv[4];
792 	struct sigaction sa;
793 
794 	switch ((pid = fork())) {
795 	case 0:
796 		(void)sigemptyset(&sa.sa_mask);
797 		sa.sa_flags = 0;
798 		sa.sa_handler = SIG_IGN;
799 		(void)sigaction(SIGTSTP, &sa, NULL);
800 		(void)sigaction(SIGHUP, &sa, NULL);
801 
802 		setctty(_PATH_CONSOLE);
803 
804 		argv[0] = "sh";
805 		argv[1] = _PATH_RUNCOM;
806 		argv[2] = (runcom_mode == AUTOBOOT ? "autoboot" : 0);
807 		argv[3] = 0;
808 
809 		(void)sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
810 
811 #ifdef CHROOT
812 		if (trychroot)
813 			if (chroot(rootdir) != 0) {
814 				warning("failed to chroot to `%s': %m",
815 				    rootdir);
816 				_exit(4); 	/* force single user mode */
817 			}
818 #endif /* CHROOT */
819 
820 		(void)execv(INIT_BSHELL, __UNCONST(argv));
821 		stall("can't exec `%s' for `%s': %m", INIT_BSHELL, _PATH_RUNCOM);
822 		_exit(5);	/* force single user mode */
823 		/*NOTREACHED*/
824 	case -1:
825 		emergency("can't fork for `%s' on `%s': %m", INIT_BSHELL,
826 		    _PATH_RUNCOM);
827 		while (waitpid(-1, NULL, WNOHANG) > 0)
828 			continue;
829 		(void)sleep(STALL_TIMEOUT);
830 		return (state_func_t)single_user;
831 	default:
832 		break;
833 	}
834 
835 	/*
836 	 * Copied from single_user().  This is a bit paranoid.
837 	 */
838 	do {
839 		if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
840 			collect_child(wpid, status);
841 		if (wpid == -1) {
842 			if (errno == EINTR)
843 				continue;
844 			warning("wait for `%s' on `%s' failed: %m; going to "
845 			    "single user mode", INIT_BSHELL, _PATH_RUNCOM);
846 			return (state_func_t)single_user;
847 		}
848 		if (wpid == pid && WIFSTOPPED(status)) {
849 			warning("`%s' on `%s' stopped, restarting",
850 			    INIT_BSHELL, _PATH_RUNCOM);
851 			(void)kill(pid, SIGCONT);
852 			wpid = -1;
853 		}
854 	} while (wpid != pid);
855 
856 	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
857 	    requested_transition == catatonia) {
858 		/* /etc/rc executed /sbin/reboot; wait for the end quietly */
859 		sigset_t s;
860 
861 		(void)sigfillset(&s);
862 		for (;;)
863 			(void)sigsuspend(&s);
864 	}
865 
866 	if (!WIFEXITED(status)) {
867 		warning("`%s' on `%s' terminated abnormally, going to "
868 		    "single user mode", INIT_BSHELL, _PATH_RUNCOM);
869 		return (state_func_t)single_user;
870 	}
871 
872 	if (WEXITSTATUS(status))
873 		return (state_func_t)single_user;
874 
875 	return (state_func_t)read_ttys;
876 }
877 
878 /*
879  * Run the system startup script.
880  */
881 state_func_t
882 runcom(void)
883 {
884 	state_func_t next_step;
885 
886 	/* Run /etc/rc and choose next state depending on the result. */
887 	next_step = runetcrc(0);
888 	if (next_step != (state_func_t)read_ttys)
889 		return (state_func_t)next_step;
890 
891 #ifdef CHROOT
892 	/*
893 	 * If init.root sysctl does not point to "/", we'll chroot and run
894 	 * The Real(tm) /etc/rc now.  Global variable rootdir will tell us
895 	 * where to go.
896 	 */
897 	if (shouldchroot()) {
898 		next_step = runetcrc(1);
899 		if (next_step != (state_func_t)read_ttys)
900 			return (state_func_t)next_step;
901 
902 		did_multiuser_chroot = 1;
903 	} else {
904 		did_multiuser_chroot = 0;
905 	}
906 #endif /* CHROOT */
907 
908 	/*
909 	 * Regardless of whether in chroot or not, we booted successfuly.
910 	 * It's time to spawn gettys (ie. next_step's value at this point).
911 	 */
912 	runcom_mode = AUTOBOOT;		/* the default */
913 	/* NB: should send a message to the session logger to avoid blocking. */
914 #ifdef SUPPORT_UTMPX
915 	logwtmpx("~", "reboot", "", 0, INIT_PROCESS);
916 #endif
917 #ifdef SUPPORT_UTMP
918 	logwtmp("~", "reboot", "");
919 #endif
920 	return (state_func_t)read_ttys;
921 }
922 
923 /*
924  * Open the session database.
925  *
926  * NB: We could pass in the size here; is it necessary?
927  */
928 int
929 start_session_db(void)
930 {
931 
932 	if (session_db && (*session_db->close)(session_db))
933 		emergency("session database close: %m");
934 	if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
935 		emergency("session database open: %m");
936 		return 1;
937 	}
938 	return 0;
939 
940 }
941 
942 /*
943  * Add a new login session.
944  */
945 void
946 add_session(session_t *sp)
947 {
948 	DBT key;
949 	DBT data;
950 
951 	if (session_db == NULL)
952 		return;
953 
954 	key.data = &sp->se_process;
955 	key.size = sizeof sp->se_process;
956 	data.data = &sp;
957 	data.size = sizeof sp;
958 
959 	if ((*session_db->put)(session_db, &key, &data, 0))
960 		emergency("insert %d: %m", sp->se_process);
961 #ifdef SUPPORT_UTMPX
962 	session_utmpx(sp, 1);
963 #endif
964 }
965 
966 /*
967  * Delete an old login session.
968  */
969 void
970 del_session(session_t *sp)
971 {
972 	DBT key;
973 
974 	key.data = &sp->se_process;
975 	key.size = sizeof sp->se_process;
976 
977 	if ((*session_db->del)(session_db, &key, 0))
978 		emergency("delete %d: %m", sp->se_process);
979 #ifdef SUPPORT_UTMPX
980 	session_utmpx(sp, 0);
981 #endif
982 }
983 
984 /*
985  * Look up a login session by pid.
986  */
987 session_t *
988 find_session(pid_t pid)
989 {
990 	DBT key;
991 	DBT data;
992 	session_t *ret;
993 
994 	if (session_db == NULL)
995 		return NULL;
996 
997 	key.data = &pid;
998 	key.size = sizeof pid;
999 	if ((*session_db->get)(session_db, &key, &data, 0) != 0)
1000 		return 0;
1001 	(void)memmove(&ret, data.data, sizeof(ret));
1002 	return ret;
1003 }
1004 
1005 /*
1006  * Construct an argument vector from a command line.
1007  */
1008 char **
1009 construct_argv(char *command)
1010 {
1011 	int argc = 0;
1012 	char **argv = malloc(((strlen(command) + 1) / 2 + 1) * sizeof (char *));
1013 	static const char separators[] = " \t";
1014 
1015 	if (argv == NULL)
1016 		return NULL;
1017 
1018 	if ((argv[argc++] = strtok(command, separators)) == 0) {
1019 		free(argv);
1020 		return NULL;
1021 	}
1022 	while ((argv[argc++] = strtok(NULL, separators)) != NULL)
1023 		continue;
1024 	return argv;
1025 }
1026 
1027 /*
1028  * Deallocate a session descriptor.
1029  */
1030 void
1031 free_session(session_t *sp)
1032 {
1033 
1034 	free(sp->se_device);
1035 	if (sp->se_getty) {
1036 		free(sp->se_getty);
1037 		free(sp->se_getty_argv);
1038 	}
1039 	if (sp->se_window) {
1040 		free(sp->se_window);
1041 		free(sp->se_window_argv);
1042 	}
1043 	free(sp);
1044 }
1045 
1046 /*
1047  * Allocate a new session descriptor.
1048  */
1049 session_t *
1050 new_session(session_t *sprev, int session_index, struct ttyent *typ)
1051 {
1052 	session_t *sp;
1053 
1054 	if ((typ->ty_status & TTY_ON) == 0 || typ->ty_name == NULL ||
1055 	    typ->ty_getty == NULL)
1056 		return NULL;
1057 
1058 	sp = malloc(sizeof (session_t));
1059 	if (sp == NULL)
1060 		return NULL;
1061 	(void)memset(sp, 0, sizeof *sp);
1062 
1063 	sp->se_flags = SE_PRESENT;
1064 	sp->se_index = session_index;
1065 
1066 	(void)asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
1067 	if (!sp->se_device)
1068 		return NULL;
1069 
1070 	if (setupargv(sp, typ) == 0) {
1071 		free_session(sp);
1072 		return NULL;
1073 	}
1074 
1075 	sp->se_next = NULL;
1076 	if (sprev == NULL) {
1077 		sessions = sp;
1078 		sp->se_prev = NULL;
1079 	} else {
1080 		sprev->se_next = sp;
1081 		sp->se_prev = sprev;
1082 	}
1083 
1084 	return sp;
1085 }
1086 
1087 /*
1088  * Calculate getty and if useful window argv vectors.
1089  */
1090 int
1091 setupargv(session_t *sp, struct ttyent *typ)
1092 {
1093 
1094 	if (sp->se_getty) {
1095 		free(sp->se_getty);
1096 		free(sp->se_getty_argv);
1097 	}
1098 	(void)asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1099 	if (!sp->se_getty)
1100 		return 0;
1101 	sp->se_getty_argv = construct_argv(sp->se_getty);
1102 	if (sp->se_getty_argv == NULL) {
1103 		warning("can't parse getty for port `%s'", sp->se_device);
1104 		free(sp->se_getty);
1105 		sp->se_getty = NULL;
1106 		return 0;
1107 	}
1108 	if (typ->ty_window) {
1109 		if (sp->se_window)
1110 			free(sp->se_window);
1111 		sp->se_window = strdup(typ->ty_window);
1112 		sp->se_window_argv = construct_argv(sp->se_window);
1113 		if (sp->se_window_argv == NULL) {
1114 			warning("can't parse window for port `%s'",
1115 			    sp->se_device);
1116 			free(sp->se_window);
1117 			sp->se_window = NULL;
1118 			return 0;
1119 		}
1120 	}
1121 	return 1;
1122 }
1123 
1124 /*
1125  * Walk the list of ttys and create sessions for each active line.
1126  */
1127 state_func_t
1128 read_ttys(void)
1129 {
1130 	int session_index = 0;
1131 	session_t *sp, *snext;
1132 	struct ttyent *typ;
1133 
1134 #ifdef SUPPORT_UTMPX
1135 	if (sessions == NULL) {
1136 		struct stat st;
1137 
1138 		make_utmpx("", BOOT_MSG, BOOT_TIME, 0, &boot_time, 0);
1139 
1140 		/*
1141 		 * If wtmpx is not empty, pick the down time from there
1142 		 */
1143 		if (stat(_PATH_WTMPX, &st) != -1 && st.st_size != 0) {
1144 			struct timeval down_time;
1145 
1146 			TIMESPEC_TO_TIMEVAL(&down_time,
1147 			    st.st_atime > st.st_mtime ?
1148 			    &st.st_atimespec : &st.st_mtimespec);
1149 			make_utmpx("", DOWN_MSG, DOWN_TIME, 0, &down_time, 0);
1150 		}
1151 	}
1152 #endif
1153 	/*
1154 	 * Destroy any previous session state.
1155 	 * There shouldn't be any, but just in case...
1156 	 */
1157 	for (sp = sessions; sp; sp = snext) {
1158 #ifndef LETS_GET_SMALL
1159 		if (sp->se_process)
1160 			clear_session_logs(sp, 0);
1161 #endif
1162 		snext = sp->se_next;
1163 		free_session(sp);
1164 	}
1165 	sessions = NULL;
1166 
1167 	if (start_session_db()) {
1168 		warning("start_session_db failed, death");
1169 #ifdef CHROOT
1170 		/* If /etc/rc ran in chroot, we want to kill any survivors. */
1171 		if (did_multiuser_chroot)
1172 			return (state_func_t)death;
1173 		else
1174 #endif /* CHROOT */
1175 			return (state_func_t)single_user;
1176 	}
1177 
1178 	(void)do_setttyent();
1179 
1180 	/*
1181 	 * Allocate a session entry for each active port.
1182 	 * Note that sp starts at 0.
1183 	 */
1184 	while ((typ = getttyent()) != NULL)
1185 		if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1186 			sp = snext;
1187 	(void)endttyent();
1188 
1189 	return (state_func_t)multi_user;
1190 }
1191 
1192 /*
1193  * Start a window system running.
1194  */
1195 void
1196 start_window_system(session_t *sp)
1197 {
1198 	pid_t pid;
1199 	sigset_t mask;
1200 
1201 	if ((pid = fork()) == -1) {
1202 		emergency("can't fork for window system on port `%s': %m",
1203 		    sp->se_device);
1204 		/* hope that getty fails and we can try again */
1205 		return;
1206 	}
1207 
1208 	if (pid)
1209 		return;
1210 
1211 	(void)sigemptyset(&mask);
1212 	(void)sigprocmask(SIG_SETMASK, &mask, NULL);
1213 
1214 	if (setsid() < 0)
1215 		emergency("setsid failed (window): %m");
1216 
1217 	(void)execv(sp->se_window_argv[0], sp->se_window_argv);
1218 	stall("can't exec window system `%s' for port `%s': %m",
1219 	    sp->se_window_argv[0], sp->se_device);
1220 	_exit(6);
1221 }
1222 
1223 /*
1224  * Start a login session running.
1225  */
1226 pid_t
1227 start_getty(session_t *sp)
1228 {
1229 	pid_t pid;
1230 	sigset_t mask;
1231 	time_t current_time = time(NULL);
1232 
1233 	/*
1234 	 * fork(), not vfork() -- we can't afford to block.
1235 	 */
1236 	if ((pid = fork()) == -1) {
1237 		emergency("can't fork for getty on port `%s': %m",
1238 		    sp->se_device);
1239 		return -1;
1240 	}
1241 
1242 	if (pid)
1243 		return pid;
1244 
1245 #ifdef CHROOT
1246 	/* If /etc/rc did proceed inside chroot, we have to try as well. */
1247 	if (did_multiuser_chroot)
1248 		if (chroot(rootdir) != 0) {
1249 			stall("can't chroot getty `%s' inside `%s': %m",
1250 			    sp->se_getty_argv[0], rootdir);
1251 			_exit(7);
1252 		}
1253 #endif /* CHROOT */
1254 
1255 	if (current_time > sp->se_started.tv_sec &&
1256 	    current_time - sp->se_started.tv_sec < GETTY_SPACING) {
1257 		warning("getty repeating too quickly on port `%s', sleeping",
1258 		    sp->se_device);
1259 		(void)sleep(GETTY_SLEEP);
1260 	}
1261 
1262 	if (sp->se_window) {
1263 		start_window_system(sp);
1264 		(void)sleep(WINDOW_WAIT);
1265 	}
1266 
1267 	(void)sigemptyset(&mask);
1268 	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1269 
1270 	(void)execv(sp->se_getty_argv[0], sp->se_getty_argv);
1271 	stall("can't exec getty `%s' for port `%s': %m",
1272 	    sp->se_getty_argv[0], sp->se_device);
1273 	_exit(8);
1274 	/*NOTREACHED*/
1275 }
1276 #ifdef SUPPORT_UTMPX
1277 static void
1278 session_utmpx(const session_t *sp, int add)
1279 {
1280 	const char *name = sp->se_getty ? sp->se_getty :
1281 	    (sp->se_window ? sp->se_window : "");
1282 	const char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
1283 
1284 	make_utmpx(name, line, add ? LOGIN_PROCESS : DEAD_PROCESS,
1285 	    sp->se_process, &sp->se_started, sp->se_index);
1286 }
1287 
1288 static void
1289 make_utmpx(const char *name, const char *line, int type, pid_t pid,
1290     const struct timeval *tv, int session)
1291 {
1292 	struct utmpx ut;
1293 	const char *eline;
1294 
1295 	(void)memset(&ut, 0, sizeof(ut));
1296 	(void)strlcpy(ut.ut_name, name, sizeof(ut.ut_name));
1297 	ut.ut_type = type;
1298 	(void)strlcpy(ut.ut_line, line, sizeof(ut.ut_line));
1299 	ut.ut_pid = pid;
1300 	if (tv)
1301 		ut.ut_tv = *tv;
1302 	else
1303 		(void)gettimeofday(&ut.ut_tv, NULL);
1304 	ut.ut_session = session;
1305 
1306 	eline = line + strlen(line);
1307 	if ((size_t)(eline - line) >= sizeof(ut.ut_id))
1308 		line = eline - sizeof(ut.ut_id);
1309 	(void)strncpy(ut.ut_id, line, sizeof(ut.ut_id));
1310 
1311 	if (pututxline(&ut) == NULL)
1312 		warning("can't add utmpx record for `%s': %m", ut.ut_line);
1313 	endutxent();
1314 }
1315 
1316 static char
1317 get_runlevel(const state_t s)
1318 {
1319 	if (s == (state_t)single_user)
1320 		return SINGLE_USER;
1321 	if (s == (state_t)runcom)
1322 		return RUNCOM;
1323 	if (s == (state_t)read_ttys)
1324 		return READ_TTYS;
1325 	if (s == (state_t)multi_user)
1326 		return MULTI_USER;
1327 	if (s == (state_t)clean_ttys)
1328 		return CLEAN_TTYS;
1329 	if (s == (state_t)catatonia)
1330 		return CATATONIA;
1331 	return DEATH;
1332 }
1333 
1334 static void
1335 utmpx_set_runlevel(char old, char new)
1336 {
1337 	struct utmpx ut;
1338 
1339 	/*
1340 	 * Don't record any transitions until we did the first transition
1341 	 * to read ttys, which is when we are guaranteed to have a read-write
1342 	 * /var. Perhaps use a different variable for this?
1343 	 */
1344 	if (sessions == NULL)
1345 		return;
1346 
1347 	(void)memset(&ut, 0, sizeof(ut));
1348 	(void)snprintf(ut.ut_line, sizeof(ut.ut_line), RUNLVL_MSG, new);
1349 	ut.ut_type = RUN_LVL;
1350 	(void)gettimeofday(&ut.ut_tv, NULL);
1351 	ut.ut_exit.e_exit = old;
1352 	ut.ut_exit.e_termination = new;
1353 	if (pututxline(&ut) == NULL)
1354 		warning("can't add utmpx record for `runlevel': %m");
1355 	endutxent();
1356 }
1357 #endif /* SUPPORT_UTMPX */
1358 
1359 #endif /* LETS_GET_SMALL */
1360 
1361 /*
1362  * Collect exit status for a child.
1363  * If an exiting login, start a new login running.
1364  */
1365 void
1366 collect_child(pid_t pid, int status)
1367 {
1368 #ifndef LETS_GET_SMALL
1369 	session_t *sp, *sprev, *snext;
1370 
1371 	if (! sessions)
1372 		return;
1373 
1374 	if ((sp = find_session(pid)) == NULL)
1375 		return;
1376 
1377 	clear_session_logs(sp, status);
1378 	del_session(sp);
1379 	sp->se_process = 0;
1380 
1381 	if (sp->se_flags & SE_SHUTDOWN) {
1382 		if ((sprev = sp->se_prev) != NULL)
1383 			sprev->se_next = sp->se_next;
1384 		else
1385 			sessions = sp->se_next;
1386 		if ((snext = sp->se_next) != NULL)
1387 			snext->se_prev = sp->se_prev;
1388 		free_session(sp);
1389 		return;
1390 	}
1391 
1392 	if ((pid = start_getty(sp)) == -1) {
1393 		/* serious trouble */
1394 		requested_transition = clean_ttys;
1395 		return;
1396 	}
1397 
1398 	sp->se_process = pid;
1399 	(void)gettimeofday(&sp->se_started, NULL);
1400 	add_session(sp);
1401 #endif /* LETS_GET_SMALL */
1402 }
1403 
1404 /*
1405  * Catch a signal and request a state transition.
1406  */
1407 void
1408 transition_handler(int sig)
1409 {
1410 
1411 	switch (sig) {
1412 #ifndef LETS_GET_SMALL
1413 	case SIGHUP:
1414 		requested_transition = clean_ttys;
1415 		break;
1416 	case SIGTERM:
1417 		requested_transition = death;
1418 		break;
1419 	case SIGTSTP:
1420 		requested_transition = catatonia;
1421 		break;
1422 #endif /* LETS_GET_SMALL */
1423 	default:
1424 		requested_transition = 0;
1425 		break;
1426 	}
1427 }
1428 
1429 #ifndef LETS_GET_SMALL
1430 /*
1431  * Take the system multiuser.
1432  */
1433 state_func_t
1434 multi_user(void)
1435 {
1436 	pid_t pid;
1437 	int status;
1438 	session_t *sp;
1439 
1440 	requested_transition = 0;
1441 
1442 	/*
1443 	 * If the administrator has not set the security level to -1
1444 	 * to indicate that the kernel should not run multiuser in secure
1445 	 * mode, and the run script has not set a higher level of security
1446 	 * than level 1, then put the kernel into secure mode.
1447 	 */
1448 	if (getsecuritylevel() == 0)
1449 		setsecuritylevel(1);
1450 
1451 	for (sp = sessions; sp; sp = sp->se_next) {
1452 		if (sp->se_process)
1453 			continue;
1454 		if ((pid = start_getty(sp)) == -1) {
1455 			/* serious trouble */
1456 			requested_transition = clean_ttys;
1457 			break;
1458 		}
1459 		sp->se_process = pid;
1460 		(void)gettimeofday(&sp->se_started, NULL);
1461 		add_session(sp);
1462 	}
1463 
1464 	while (!requested_transition)
1465 		if ((pid = waitpid(-1, &status, 0)) != -1)
1466 			collect_child(pid, status);
1467 
1468 	return (state_func_t)requested_transition;
1469 }
1470 
1471 /*
1472  * This is an n-squared algorithm.  We hope it isn't run often...
1473  */
1474 state_func_t
1475 clean_ttys(void)
1476 {
1477 	session_t *sp, *sprev;
1478 	struct ttyent *typ;
1479 	int session_index = 0;
1480 	int devlen;
1481 
1482 	for (sp = sessions; sp; sp = sp->se_next)
1483 		sp->se_flags &= ~SE_PRESENT;
1484 
1485 	(void)do_setttyent();
1486 
1487 	devlen = sizeof(_PATH_DEV) - 1;
1488 	while ((typ = getttyent()) != NULL) {
1489 		++session_index;
1490 
1491 		for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1492 			if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1493 				break;
1494 
1495 		if (sp) {
1496 			sp->se_flags |= SE_PRESENT;
1497 			if (sp->se_index != session_index) {
1498 				warning("port `%s' changed utmp index from "
1499 				    "%d to %d", sp->se_device, sp->se_index,
1500 				    session_index);
1501 				sp->se_index = session_index;
1502 			}
1503 			if ((typ->ty_status & TTY_ON) == 0 ||
1504 			    typ->ty_getty == 0) {
1505 				sp->se_flags |= SE_SHUTDOWN;
1506 				if (sp->se_process != 0)
1507 					(void)kill(sp->se_process, SIGHUP);
1508 				continue;
1509 			}
1510 			sp->se_flags &= ~SE_SHUTDOWN;
1511 			if (setupargv(sp, typ) == 0) {
1512 				warning("can't parse getty for port `%s'",
1513 				    sp->se_device);
1514 				sp->se_flags |= SE_SHUTDOWN;
1515 				if (sp->se_process != 0)
1516 					(void)kill(sp->se_process, SIGHUP);
1517 			}
1518 			continue;
1519 		}
1520 
1521 		(void)new_session(sprev, session_index, typ);
1522 	}
1523 
1524 	(void)endttyent();
1525 
1526 	for (sp = sessions; sp; sp = sp->se_next)
1527 		if ((sp->se_flags & SE_PRESENT) == 0) {
1528 			sp->se_flags |= SE_SHUTDOWN;
1529 			if (sp->se_process != 0)
1530 				(void)kill(sp->se_process, SIGHUP);
1531 		}
1532 
1533 	return (state_func_t)multi_user;
1534 }
1535 
1536 /*
1537  * Block further logins.
1538  */
1539 state_func_t
1540 catatonia(void)
1541 {
1542 	session_t *sp;
1543 
1544 	for (sp = sessions; sp; sp = sp->se_next)
1545 		sp->se_flags |= SE_SHUTDOWN;
1546 
1547 	return (state_func_t)multi_user;
1548 }
1549 #endif /* LETS_GET_SMALL */
1550 
1551 /*
1552  * Note SIGALRM.
1553  */
1554 void
1555 /*ARGSUSED*/
1556 alrm_handler(int sig)
1557 {
1558 
1559 	clang = 1;
1560 }
1561 
1562 #ifndef LETS_GET_SMALL
1563 /*
1564  * Bring the system down to single user.
1565  */
1566 state_func_t
1567 death(void)
1568 {
1569 	session_t *sp;
1570 	int i, status;
1571 	pid_t pid;
1572 	static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL };
1573 
1574 	for (sp = sessions; sp; sp = sp->se_next)
1575 		sp->se_flags |= SE_SHUTDOWN;
1576 
1577 	/* NB: should send a message to the session logger to avoid blocking. */
1578 #ifdef SUPPORT_UTMPX
1579 	logwtmpx("~", "shutdown", "", 0, INIT_PROCESS);
1580 #endif
1581 #ifdef SUPPORT_UTMP
1582 	logwtmp("~", "shutdown", "");
1583 #endif
1584 
1585 	for (i = 0; i < 3; ++i) {
1586 		if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1587 			return (state_func_t)single_user;
1588 
1589 		clang = 0;
1590 		(void)alarm(DEATH_WATCH);
1591 		do
1592 			if ((pid = waitpid(-1, &status, 0)) != -1)
1593 				collect_child(pid, status);
1594 		while (clang == 0 && errno != ECHILD);
1595 
1596 		if (errno == ECHILD)
1597 			return (state_func_t)single_user;
1598 	}
1599 
1600 	warning("some processes would not die; ps axl advised");
1601 
1602 	return (state_func_t)single_user;
1603 }
1604 #endif /* LETS_GET_SMALL */
1605 
1606 #ifdef MFS_DEV_IF_NO_CONSOLE
1607 
1608 static int
1609 mfs_dev(void)
1610 {
1611 	/*
1612 	 * We cannot print errors so we bail out silently...
1613 	 */
1614 	pid_t pid;
1615 	int status;
1616 
1617 	/* If we have /dev/console, assume all is OK  */
1618 	if (access(_PATH_CONSOLE, F_OK) == 0)
1619 		return 0;
1620 
1621 #if 0	/* Useful for testing MAKEDEV */
1622 	/* Mount an mfs over /mnt so we can create a console entry */
1623 	switch ((pid = fork())) {
1624 	case 0:
1625 		(void)execl(INIT_MOUNT_MFS, "mount_mfs",
1626 		    "-b", "4096", "-f", "512",
1627 		    "-s", 64, "-n", 10,
1628 		    "-p", "0755",
1629 		    "swap", "/mnt", NULL);
1630 		_exit(9);
1631 		/*NOTREACHED*/
1632 
1633 	case -1:
1634 		return(-1);
1635 
1636 	default:
1637 		if (waitpid(pid, &status, 0) == -1)
1638 			return(-1);
1639 		if (status != 0)
1640 			return(-1);
1641 		break;
1642 	}
1643 
1644 	{
1645 		dev_t dev;
1646 #ifdef CPU_CONSDEV
1647 		static int name[2] = { CTL_MACHDEP, CPU_CONSDEV };
1648 		size_t olen;
1649 		olen = sizeof(dev);
1650 		if (sysctl(name, sizeof(name) / sizeof(name[0]), &dev, &olen,
1651 		    NULL, 0) == -1)
1652 #endif
1653 			dev = makedev(0, 0);
1654 
1655 		/* Make a console for us, so we can see things happening */
1656 		if (mknod("/mnt/console", 0666 | S_IFCHR, dev) == -1)
1657 			return(-1);
1658 		(void)freopen("/mnt/console", "a", stderr);
1659 	}
1660 
1661 #endif
1662 
1663 	/* Run the makedev script to create devices */
1664 	switch ((pid = fork())) {
1665 	case 0:
1666 		(void)dup2(2, 1);	/* Give the script stdout */
1667 		if (chdir("/dev") == 0)
1668 			(void)execl(INIT_BSHELL, "sh",
1669 			    access("./MAKEDEV", X_OK) == 0
1670 				? "./MAKEDEV" : "/etc/MAKEDEV",
1671 			    "-MM", "init", NULL);
1672 		_exit(10);
1673 		/* NOTREACHED */
1674 
1675 	case -1:
1676 		break;
1677 
1678 	default:
1679 		if (waitpid(pid, &status, 0) == -1)
1680 			break;
1681 		if (status != 0)
1682 			warn("MAKEDEV exit status %d\n", status);
1683 		/*
1684 		 * If /dev/console got created, then return 0
1685 		 * regardless of MAKEDEV exit status.
1686 		 */
1687 		if (access(_PATH_CONSOLE, F_OK) == 0)
1688 			return 0;
1689 		_exit(11);
1690 	}
1691 	warn("Unable to run MAKEDEV");
1692 	_exit(12);
1693 }
1694 #endif
1695 
1696 int
1697 do_setttyent(void)
1698 {
1699 	(void)endttyent();
1700 #ifdef CHROOT
1701 	if (did_multiuser_chroot) {
1702 		char path[PATH_MAX];
1703 
1704 		(void)snprintf(path, sizeof(path), "%s/%s", rootdir, _PATH_TTYS);
1705 
1706 		return setttyentpath(path);
1707 	} else
1708 #endif /* CHROOT */
1709 		return setttyent();
1710 }
1711 
1712 #if !defined(LETS_GET_SMALL) && defined(CHROOT)
1713 
1714 int
1715 createsysctlnode()
1716 {
1717 	struct sysctlnode node;
1718 	int mib[2];
1719 	size_t len;
1720 
1721 	/*
1722 	 * Create top-level dynamic sysctl node.  Its child nodes will only
1723 	 * be readable by the superuser, since regular mortals should not
1724 	 * care ("Sssh, it's a secret!").
1725 	 */
1726 	len = sizeof(struct sysctlnode);
1727 	mib[0] = CTL_CREATE;
1728 
1729 	(void)memset(&node, 0, len);
1730 	node.sysctl_flags = SYSCTL_VERSION | CTLFLAG_READWRITE |
1731 	    CTLFLAG_PRIVATE | CTLTYPE_NODE;
1732 	node.sysctl_num = CTL_CREATE;
1733 	(void)snprintf(node.sysctl_name, SYSCTL_NAMELEN, "init");
1734 	if (sysctl(&mib[0], 1, &node, &len, &node, len) == -1) {
1735 		warning("could not create init node: %m");
1736 		return -1;
1737 	}
1738 
1739 	/*
1740 	 * Create second level dynamic node capable of holding pathname.
1741 	 * Provide "/" as the default value.
1742 	 */
1743 	len = sizeof(struct sysctlnode);
1744 	mib[0] = node.sysctl_num;
1745 	mib[1] = CTL_CREATE;
1746 
1747 	(void)memset(&node, 0, len);
1748 	node.sysctl_flags = SYSCTL_VERSION | CTLFLAG_READWRITE |
1749 	    CTLTYPE_STRING | CTLFLAG_OWNDATA;
1750 	node.sysctl_size = _POSIX_PATH_MAX;
1751 	node.sysctl_data = __UNCONST("/");
1752 	node.sysctl_num = CTL_CREATE;
1753 	(void)snprintf(node.sysctl_name, SYSCTL_NAMELEN, "root");
1754 	if (sysctl(&mib[0], 2, NULL, NULL, &node, len) == -1) {
1755 		warning("could not create init.root node: %m");
1756 		return -1;
1757 	}
1758 
1759 	return 0;
1760 }
1761 
1762 int
1763 shouldchroot()
1764 {
1765 	struct sysctlnode node;
1766 	size_t len, cnt;
1767 	int mib;
1768 
1769 	len = sizeof(struct sysctlnode);
1770 
1771 	if (sysctlbyname("init.root", rootdir, &len, NULL, 0) == -1) {
1772 		warning("could not read init.root: %m");
1773 
1774 		/* Child killed our node. Recreate it. */
1775 		if (errno == ENOENT) {
1776 			/* Destroy whatever is left, recreate from scratch. */
1777 			if (sysctlnametomib("init", &mib, &cnt) != -1) {
1778 				(void)memset(&node, 0, sizeof(node));
1779 				node.sysctl_flags = SYSCTL_VERSION;
1780 				node.sysctl_num = mib;
1781 				mib = CTL_DESTROY;
1782 
1783 				(void)sysctl(&mib, 1, NULL, NULL, &node,
1784 				    sizeof(node));
1785 			}
1786 
1787 			(void)createsysctlnode();
1788 		}
1789 
1790 		/* We certainly won't chroot. */
1791 		return 0;
1792 	}
1793 
1794 	if (rootdir[len] != '\0' || strlen(rootdir) != len - 1) {
1795 		warning("init.root is not a string");
1796 		return 0;
1797 	}
1798 
1799 	if (strcmp(rootdir, "/") == 0)
1800 		return 0;
1801 
1802 	return 1;
1803 }
1804 
1805 #endif /* !LETS_GET_SMALL && CHROOT */
1806