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/mman.h>
50 #include <sys/mount.h>
51 #include <sys/sysctl.h>
52 #include <sys/wait.h>
53 #include <sys/stat.h>
54 #include <sys/uio.h>
55
56 #include <db.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <kenv.h>
60 #include <libutil.h>
61 #include <paths.h>
62 #include <signal.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <syslog.h>
67 #include <time.h>
68 #include <ttyent.h>
69 #include <unistd.h>
70 #include <sys/reboot.h>
71 #include <err.h>
72
73 #include <stdarg.h>
74
75 #ifdef SECURE
76 #include <pwd.h>
77 #endif
78
79 #ifdef LOGIN_CAP
80 #include <login_cap.h>
81 #endif
82
83 #include "mntopts.h"
84 #include "pathnames.h"
85
86 /*
87 * Sleep times; used to prevent thrashing.
88 */
89 #define GETTY_SPACING 5 /* N secs minimum getty spacing */
90 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */
91 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */
92 #define WINDOW_WAIT 3 /* wait N secs after starting window */
93 #define STALL_TIMEOUT 30 /* wait N secs after warning */
94 #define DEATH_WATCH 10 /* wait N secs for procs to die */
95 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */
96 #define RESOURCE_RC "daemon"
97 #define RESOURCE_WINDOW "default"
98 #define RESOURCE_GETTY "default"
99
100 static void handle(sig_t, ...);
101 static void delset(sigset_t *, ...);
102
103 static void stall(const char *, ...) __printflike(1, 2);
104 static void warning(const char *, ...) __printflike(1, 2);
105 static void emergency(const char *, ...) __printflike(1, 2);
106 static void disaster(int);
107 static void badsys(int);
108 static void revoke_ttys(void);
109 static int runshutdown(void);
110 static char *strk(char *);
111
112 /*
113 * We really need a recursive typedef...
114 * The following at least guarantees that the return type of (*state_t)()
115 * is sufficiently wide to hold a function pointer.
116 */
117 typedef long (*state_func_t)(void);
118 typedef state_func_t (*state_t)(void);
119
120 static state_func_t single_user(void);
121 static state_func_t runcom(void);
122 static state_func_t read_ttys(void);
123 static state_func_t multi_user(void);
124 static state_func_t clean_ttys(void);
125 static state_func_t catatonia(void);
126 static state_func_t death(void);
127 static state_func_t death_single(void);
128 static state_func_t reroot(void);
129 static state_func_t reroot_phase_two(void);
130
131 static state_func_t run_script(const char *);
132
133 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
134 #define FALSE 0
135 #define TRUE 1
136
137 static int Reboot = FALSE;
138 static int howto = RB_AUTOBOOT;
139
140 static int devfs;
141
142 static void transition(state_t);
143 static state_t requested_transition;
144 static state_t current_state = death_single;
145
146 static void open_console(void);
147 static const char *get_shell(void);
148 static void write_stderr(const char *message);
149
150 typedef struct init_session {
151 pid_t se_process; /* controlling process */
152 time_t se_started; /* used to avoid thrashing */
153 int se_flags; /* status of session */
154 #define SE_SHUTDOWN 0x1 /* session won't be restarted */
155 #define SE_PRESENT 0x2 /* session is in /etc/ttys */
156 int se_nspace; /* spacing count */
157 char *se_device; /* filename of port */
158 char *se_getty; /* what to run on that port */
159 char *se_getty_argv_space; /* pre-parsed argument array space */
160 char **se_getty_argv; /* pre-parsed argument array */
161 char *se_window; /* window system (started only once) */
162 char *se_window_argv_space; /* pre-parsed argument array space */
163 char **se_window_argv; /* pre-parsed argument array */
164 char *se_type; /* default terminal type */
165 struct init_session *se_prev;
166 struct init_session *se_next;
167 } session_t;
168
169 static void free_session(session_t *);
170 static session_t *new_session(session_t *, struct ttyent *);
171 static session_t *sessions;
172
173 static char **construct_argv(char *);
174 static void start_window_system(session_t *);
175 static void collect_child(pid_t);
176 static pid_t start_getty(session_t *);
177 static void transition_handler(int);
178 static void alrm_handler(int);
179 static void setsecuritylevel(int);
180 static int getsecuritylevel(void);
181 static int setupargv(session_t *, struct ttyent *);
182 #ifdef LOGIN_CAP
183 static void setprocresources(const char *);
184 #endif
185 static int clang;
186
187 static int start_session_db(void);
188 static void add_session(session_t *);
189 static void del_session(session_t *);
190 static session_t *find_session(pid_t);
191 static DB *session_db;
192
193 /*
194 * The mother of all processes.
195 */
196 int
main(int argc,char * argv[])197 main(int argc, char *argv[])
198 {
199 state_t initial_transition = runcom;
200 char kenv_value[PATH_MAX];
201 int c, error;
202 struct sigaction sa;
203 sigset_t mask;
204
205 /* Dispose of random users. */
206 if (getuid() != 0)
207 errx(1, "%s", strerror(EPERM));
208
209 /* System V users like to reexec init. */
210 if (getpid() != 1) {
211 #ifdef COMPAT_SYSV_INIT
212 /* So give them what they want */
213 if (argc > 1) {
214 if (strlen(argv[1]) == 1) {
215 char runlevel = *argv[1];
216 int sig;
217
218 switch (runlevel) {
219 case '0': /* halt + poweroff */
220 sig = SIGUSR2;
221 break;
222 case '1': /* single-user */
223 sig = SIGTERM;
224 break;
225 case '6': /* reboot */
226 sig = SIGINT;
227 break;
228 case 'c': /* block further logins */
229 sig = SIGTSTP;
230 break;
231 case 'q': /* rescan /etc/ttys */
232 sig = SIGHUP;
233 break;
234 case 'r': /* remount root */
235 sig = SIGEMT;
236 break;
237 default:
238 goto invalid;
239 }
240 kill(1, sig);
241 _exit(0);
242 } else
243 invalid:
244 errx(1, "invalid run-level ``%s''", argv[1]);
245 } else
246 #endif
247 errx(1, "already running");
248 }
249 /*
250 * Note that this does NOT open a file...
251 * Does 'init' deserve its own facility number?
252 */
253 openlog("init", LOG_CONS, LOG_AUTH);
254
255 /*
256 * Create an initial session.
257 */
258 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1))
259 warning("initial setsid() failed: %m");
260
261 /*
262 * Establish an initial user so that programs running
263 * single user do not freak out and die (like passwd).
264 */
265 if (setlogin("root") < 0)
266 warning("setlogin() failed: %m");
267
268 /*
269 * This code assumes that we always get arguments through flags,
270 * never through bits set in some random machine register.
271 */
272 while ((c = getopt(argc, argv, "dsfr")) != -1)
273 switch (c) {
274 case 'd':
275 devfs = 1;
276 break;
277 case 's':
278 initial_transition = single_user;
279 break;
280 case 'f':
281 runcom_mode = FASTBOOT;
282 break;
283 case 'r':
284 initial_transition = reroot_phase_two;
285 break;
286 default:
287 warning("unrecognized flag '-%c'", c);
288 break;
289 }
290
291 if (optind != argc)
292 warning("ignoring excess arguments");
293
294 /*
295 * We catch or block signals rather than ignore them,
296 * so that they get reset on exec.
297 */
298 handle(badsys, SIGSYS, 0);
299 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU,
300 SIGXFSZ, 0);
301 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
302 SIGUSR1, SIGUSR2, 0);
303 handle(alrm_handler, SIGALRM, 0);
304 sigfillset(&mask);
305 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
306 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
307 SIGALRM, SIGUSR1, SIGUSR2, 0);
308 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
309 sigemptyset(&sa.sa_mask);
310 sa.sa_flags = 0;
311 sa.sa_handler = SIG_IGN;
312 sigaction(SIGTTIN, &sa, (struct sigaction *)0);
313 sigaction(SIGTTOU, &sa, (struct sigaction *)0);
314
315 /*
316 * Paranoia.
317 */
318 close(0);
319 close(1);
320 close(2);
321
322 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
323 state_func_t next_transition;
324
325 if ((next_transition = run_script(kenv_value)) != 0)
326 initial_transition = (state_t) next_transition;
327 }
328
329 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
330 if (chdir(kenv_value) != 0 || chroot(".") != 0)
331 warning("Can't chroot to %s: %m", kenv_value);
332 }
333
334 /*
335 * Additional check if devfs needs to be mounted:
336 * If "/" and "/dev" have the same device number,
337 * then it hasn't been mounted yet.
338 */
339 if (!devfs) {
340 struct stat stst;
341 dev_t root_devno;
342
343 stat("/", &stst);
344 root_devno = stst.st_dev;
345 if (stat("/dev", &stst) != 0)
346 warning("Can't stat /dev: %m");
347 else if (stst.st_dev == root_devno)
348 devfs++;
349 }
350
351 if (devfs) {
352 struct iovec iov[4];
353 char *s;
354 int i;
355
356 char _fstype[] = "fstype";
357 char _devfs[] = "devfs";
358 char _fspath[] = "fspath";
359 char _path_dev[]= _PATH_DEV;
360
361 iov[0].iov_base = _fstype;
362 iov[0].iov_len = sizeof(_fstype);
363 iov[1].iov_base = _devfs;
364 iov[1].iov_len = sizeof(_devfs);
365 iov[2].iov_base = _fspath;
366 iov[2].iov_len = sizeof(_fspath);
367 /*
368 * Try to avoid the trailing slash in _PATH_DEV.
369 * Be *very* defensive.
370 */
371 s = strdup(_PATH_DEV);
372 if (s != NULL) {
373 i = strlen(s);
374 if (i > 0 && s[i - 1] == '/')
375 s[i - 1] = '\0';
376 iov[3].iov_base = s;
377 iov[3].iov_len = strlen(s) + 1;
378 } else {
379 iov[3].iov_base = _path_dev;
380 iov[3].iov_len = sizeof(_path_dev);
381 }
382 nmount(iov, 4, 0);
383 if (s != NULL)
384 free(s);
385 }
386
387 if (initial_transition != reroot_phase_two) {
388 /*
389 * Unmount reroot leftovers. This runs after init(8)
390 * gets reexecuted after reroot_phase_two() is done.
391 */
392 error = unmount(_PATH_REROOT, MNT_FORCE);
393 if (error != 0 && errno != EINVAL)
394 warning("Cannot unmount %s: %m", _PATH_REROOT);
395 }
396
397 /*
398 * Start the state machine.
399 */
400 transition(initial_transition);
401
402 /*
403 * Should never reach here.
404 */
405 return 1;
406 }
407
408 /*
409 * Associate a function with a signal handler.
410 */
411 static void
handle(sig_t handler,...)412 handle(sig_t handler, ...)
413 {
414 int sig;
415 struct sigaction sa;
416 sigset_t mask_everything;
417 va_list ap;
418 va_start(ap, handler);
419
420 sa.sa_handler = handler;
421 sigfillset(&mask_everything);
422
423 while ((sig = va_arg(ap, int)) != 0) {
424 sa.sa_mask = mask_everything;
425 /* XXX SA_RESTART? */
426 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
427 sigaction(sig, &sa, (struct sigaction *) 0);
428 }
429 va_end(ap);
430 }
431
432 /*
433 * Delete a set of signals from a mask.
434 */
435 static void
delset(sigset_t * maskp,...)436 delset(sigset_t *maskp, ...)
437 {
438 int sig;
439 va_list ap;
440 va_start(ap, maskp);
441
442 while ((sig = va_arg(ap, int)) != 0)
443 sigdelset(maskp, sig);
444 va_end(ap);
445 }
446
447 /*
448 * Log a message and sleep for a while (to give someone an opportunity
449 * to read it and to save log or hardcopy output if the problem is chronic).
450 * NB: should send a message to the session logger to avoid blocking.
451 */
452 static void
stall(const char * message,...)453 stall(const char *message, ...)
454 {
455 va_list ap;
456 va_start(ap, message);
457
458 vsyslog(LOG_ALERT, message, ap);
459 va_end(ap);
460 sleep(STALL_TIMEOUT);
461 }
462
463 /*
464 * Like stall(), but doesn't sleep.
465 * If cpp had variadic macros, the two functions could be #defines for another.
466 * NB: should send a message to the session logger to avoid blocking.
467 */
468 static void
warning(const char * message,...)469 warning(const char *message, ...)
470 {
471 va_list ap;
472 va_start(ap, message);
473
474 vsyslog(LOG_ALERT, message, ap);
475 va_end(ap);
476 }
477
478 /*
479 * Log an emergency message.
480 * NB: should send a message to the session logger to avoid blocking.
481 */
482 static void
emergency(const char * message,...)483 emergency(const char *message, ...)
484 {
485 va_list ap;
486 va_start(ap, message);
487
488 vsyslog(LOG_EMERG, message, ap);
489 va_end(ap);
490 }
491
492 /*
493 * Catch a SIGSYS signal.
494 *
495 * These may arise if a system does not support sysctl.
496 * We tolerate up to 25 of these, then throw in the towel.
497 */
498 static void
badsys(int sig)499 badsys(int sig)
500 {
501 static int badcount = 0;
502
503 if (badcount++ < 25)
504 return;
505 disaster(sig);
506 }
507
508 /*
509 * Catch an unexpected signal.
510 */
511 static void
disaster(int sig)512 disaster(int sig)
513 {
514
515 emergency("fatal signal: %s",
516 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
517
518 sleep(STALL_TIMEOUT);
519 _exit(sig); /* reboot */
520 }
521
522 /*
523 * Get the security level of the kernel.
524 */
525 static int
getsecuritylevel(void)526 getsecuritylevel(void)
527 {
528 #ifdef KERN_SECURELVL
529 int name[2], curlevel;
530 size_t len;
531
532 name[0] = CTL_KERN;
533 name[1] = KERN_SECURELVL;
534 len = sizeof curlevel;
535 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
536 emergency("cannot get kernel security level: %s",
537 strerror(errno));
538 return (-1);
539 }
540 return (curlevel);
541 #else
542 return (-1);
543 #endif
544 }
545
546 /*
547 * Set the security level of the kernel.
548 */
549 static void
setsecuritylevel(int newlevel)550 setsecuritylevel(int newlevel)
551 {
552 #ifdef KERN_SECURELVL
553 int name[2], curlevel;
554
555 curlevel = getsecuritylevel();
556 if (newlevel == curlevel)
557 return;
558 name[0] = CTL_KERN;
559 name[1] = KERN_SECURELVL;
560 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
561 emergency(
562 "cannot change kernel security level from %d to %d: %s",
563 curlevel, newlevel, strerror(errno));
564 return;
565 }
566 #ifdef SECURE
567 warning("kernel security level changed from %d to %d",
568 curlevel, newlevel);
569 #endif
570 #endif
571 }
572
573 /*
574 * Change states in the finite state machine.
575 * The initial state is passed as an argument.
576 */
577 static void
transition(state_t s)578 transition(state_t s)
579 {
580
581 current_state = s;
582 for (;;)
583 current_state = (state_t) (*current_state)();
584 }
585
586 /*
587 * Start a session and allocate a controlling terminal.
588 * Only called by children of init after forking.
589 */
590 static void
open_console(void)591 open_console(void)
592 {
593 int fd;
594
595 /*
596 * Try to open /dev/console. Open the device with O_NONBLOCK to
597 * prevent potential blocking on a carrier.
598 */
599 revoke(_PATH_CONSOLE);
600 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) {
601 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
602 if (login_tty(fd) == 0)
603 return;
604 close(fd);
605 }
606
607 /* No luck. Log output to file if possible. */
608 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
609 stall("cannot open null device.");
610 _exit(1);
611 }
612 if (fd != STDIN_FILENO) {
613 dup2(fd, STDIN_FILENO);
614 close(fd);
615 }
616 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644);
617 if (fd == -1)
618 dup2(STDIN_FILENO, STDOUT_FILENO);
619 else if (fd != STDOUT_FILENO) {
620 dup2(fd, STDOUT_FILENO);
621 close(fd);
622 }
623 dup2(STDOUT_FILENO, STDERR_FILENO);
624 }
625
626 static const char *
get_shell(void)627 get_shell(void)
628 {
629 static char kenv_value[PATH_MAX];
630
631 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
632 return kenv_value;
633 else
634 return _PATH_BSHELL;
635 }
636
637 static void
write_stderr(const char * message)638 write_stderr(const char *message)
639 {
640
641 write(STDERR_FILENO, message, strlen(message));
642 }
643
644 static int
read_file(const char * path,void ** bufp,size_t * bufsizep)645 read_file(const char *path, void **bufp, size_t *bufsizep)
646 {
647 struct stat sb;
648 size_t bufsize;
649 void *buf;
650 ssize_t nbytes;
651 int error, fd;
652
653 fd = open(path, O_RDONLY);
654 if (fd < 0) {
655 emergency("%s: %s", path, strerror(errno));
656 return (-1);
657 }
658
659 error = fstat(fd, &sb);
660 if (error != 0) {
661 emergency("fstat: %s", strerror(errno));
662 close(fd);
663 return (error);
664 }
665
666 bufsize = sb.st_size;
667 buf = malloc(bufsize);
668 if (buf == NULL) {
669 emergency("malloc: %s", strerror(errno));
670 close(fd);
671 return (error);
672 }
673
674 nbytes = read(fd, buf, bufsize);
675 if (nbytes != (ssize_t)bufsize) {
676 emergency("read: %s", strerror(errno));
677 close(fd);
678 free(buf);
679 return (error);
680 }
681
682 error = close(fd);
683 if (error != 0) {
684 emergency("close: %s", strerror(errno));
685 free(buf);
686 return (error);
687 }
688
689 *bufp = buf;
690 *bufsizep = bufsize;
691
692 return (0);
693 }
694
695 static int
create_file(const char * path,const void * buf,size_t bufsize)696 create_file(const char *path, const void *buf, size_t bufsize)
697 {
698 ssize_t nbytes;
699 int error, fd;
700
701 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700);
702 if (fd < 0) {
703 emergency("%s: %s", path, strerror(errno));
704 return (-1);
705 }
706
707 nbytes = write(fd, buf, bufsize);
708 if (nbytes != (ssize_t)bufsize) {
709 emergency("write: %s", strerror(errno));
710 close(fd);
711 return (-1);
712 }
713
714 error = close(fd);
715 if (error != 0) {
716 emergency("close: %s", strerror(errno));
717 return (-1);
718 }
719
720 return (0);
721 }
722
723 static int
mount_tmpfs(const char * fspath)724 mount_tmpfs(const char *fspath)
725 {
726 struct iovec *iov;
727 char errmsg[255];
728 int error, iovlen;
729
730 iov = NULL;
731 iovlen = 0;
732 memset(errmsg, 0, sizeof(errmsg));
733 build_iovec(&iov, &iovlen, "fstype",
734 __DECONST(void *, "tmpfs"), (size_t)-1);
735 build_iovec(&iov, &iovlen, "fspath",
736 __DECONST(void *, fspath), (size_t)-1);
737 build_iovec(&iov, &iovlen, "errmsg",
738 errmsg, sizeof(errmsg));
739
740 error = nmount(iov, iovlen, 0);
741 if (error != 0) {
742 if (*errmsg != '\0') {
743 emergency("cannot mount tmpfs on %s: %s: %s",
744 fspath, errmsg, strerror(errno));
745 } else {
746 emergency("cannot mount tmpfs on %s: %s",
747 fspath, strerror(errno));
748 }
749 return (error);
750 }
751 return (0);
752 }
753
754 static state_func_t
reroot(void)755 reroot(void)
756 {
757 void *buf;
758 char init_path[PATH_MAX];
759 size_t bufsize, init_path_len;
760 int error, name[4];
761
762 buf = NULL;
763 bufsize = 0;
764
765 name[0] = CTL_KERN;
766 name[1] = KERN_PROC;
767 name[2] = KERN_PROC_PATHNAME;
768 name[3] = -1;
769 init_path_len = sizeof(init_path);
770 error = sysctl(name, 4, init_path, &init_path_len, NULL, 0);
771 if (error != 0) {
772 emergency("failed to get kern.proc.pathname: %s",
773 strerror(errno));
774 goto out;
775 }
776
777 revoke_ttys();
778 runshutdown();
779
780 /*
781 * Make sure nobody can interfere with our scheme.
782 */
783 error = kill(-1, SIGKILL);
784 if (error != 0) {
785 emergency("kill(2) failed: %s", strerror(errno));
786 goto out;
787 }
788
789 /*
790 * Copy the init binary into tmpfs, so that we can unmount
791 * the old rootfs without committing suicide.
792 */
793 error = read_file(init_path, &buf, &bufsize);
794 if (error != 0)
795 goto out;
796 error = mount_tmpfs(_PATH_REROOT);
797 if (error != 0)
798 goto out;
799 error = create_file(_PATH_REROOT_INIT, buf, bufsize);
800 if (error != 0)
801 goto out;
802
803 /*
804 * Execute the temporary init.
805 */
806 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL);
807 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno));
808
809 out:
810 emergency("reroot failed; going to single user mode");
811 free(buf);
812 return (state_func_t) single_user;
813 }
814
815 static state_func_t
reroot_phase_two(void)816 reroot_phase_two(void)
817 {
818 char init_path[PATH_MAX], *path, *path_component;
819 size_t init_path_len;
820 int nbytes, error;
821
822 /*
823 * Ask the kernel to mount the new rootfs.
824 */
825 error = reboot(RB_REROOT);
826 if (error != 0) {
827 emergency("RB_REBOOT failed: %s", strerror(errno));
828 goto out;
829 }
830
831 /*
832 * Figure out where the destination init(8) binary is. Note that
833 * the path could be different than what we've started with. Use
834 * the value from kenv, if set, or the one from sysctl otherwise.
835 * The latter defaults to a hardcoded value, but can be overridden
836 * by a build time option.
837 */
838 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path));
839 if (nbytes <= 0) {
840 init_path_len = sizeof(init_path);
841 error = sysctlbyname("kern.init_path",
842 init_path, &init_path_len, NULL, 0);
843 if (error != 0) {
844 emergency("failed to retrieve kern.init_path: %s",
845 strerror(errno));
846 goto out;
847 }
848 }
849
850 /*
851 * Repeat the init search logic from sys/kern/init_path.c
852 */
853 path_component = init_path;
854 while ((path = strsep(&path_component, ":")) != NULL) {
855 /*
856 * Execute init(8) from the new rootfs.
857 */
858 execl(path, path, NULL);
859 }
860 emergency("cannot exec init from %s: %s", init_path, strerror(errno));
861
862 out:
863 emergency("reroot failed; going to single user mode");
864 return (state_func_t) single_user;
865 }
866
867 /*
868 * Bring the system up single user.
869 */
870 static state_func_t
single_user(void)871 single_user(void)
872 {
873 pid_t pid, wpid;
874 int status;
875 sigset_t mask;
876 const char *shell;
877 char *argv[2];
878 #ifdef SECURE
879 struct ttyent *typ;
880 struct passwd *pp;
881 static const char banner[] =
882 "Enter root password, or ^D to go multi-user\n";
883 char *clear, *password;
884 #endif
885 #ifdef DEBUGSHELL
886 char altshell[128];
887 #endif
888
889 if (Reboot) {
890 /* Instead of going single user, let's reboot the machine */
891 sync();
892 reboot(howto);
893 _exit(0);
894 }
895
896 shell = get_shell();
897
898 if ((pid = fork()) == 0) {
899 /*
900 * Start the single user session.
901 */
902 open_console();
903
904 #ifdef SECURE
905 /*
906 * Check the root password.
907 * We don't care if the console is 'on' by default;
908 * it's the only tty that can be 'off' and 'secure'.
909 */
910 typ = getttynam("console");
911 pp = getpwnam("root");
912 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
913 pp && *pp->pw_passwd) {
914 write_stderr(banner);
915 for (;;) {
916 clear = getpass("Password:");
917 if (clear == 0 || *clear == '\0')
918 _exit(0);
919 password = crypt(clear, pp->pw_passwd);
920 bzero(clear, _PASSWORD_LEN);
921 if (password == NULL ||
922 strcmp(password, pp->pw_passwd) == 0)
923 break;
924 warning("single-user login failed\n");
925 }
926 }
927 endttyent();
928 endpwent();
929 #endif /* SECURE */
930
931 #ifdef DEBUGSHELL
932 {
933 char *cp = altshell;
934 int num;
935
936 #define SHREQUEST "Enter full pathname of shell or RETURN for "
937 write_stderr(SHREQUEST);
938 write_stderr(shell);
939 write_stderr(": ");
940 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
941 num != 0 && *cp != '\n' && cp < &altshell[127])
942 cp++;
943 *cp = '\0';
944 if (altshell[0] != '\0')
945 shell = altshell;
946 }
947 #endif /* DEBUGSHELL */
948
949 /*
950 * Unblock signals.
951 * We catch all the interesting ones,
952 * and those are reset to SIG_DFL on exec.
953 */
954 sigemptyset(&mask);
955 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
956
957 /*
958 * Fire off a shell.
959 * If the default one doesn't work, try the Bourne shell.
960 */
961
962 char name[] = "-sh";
963
964 argv[0] = name;
965 argv[1] = 0;
966 execv(shell, argv);
967 emergency("can't exec %s for single user: %m", shell);
968 execv(_PATH_BSHELL, argv);
969 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
970 sleep(STALL_TIMEOUT);
971 _exit(1);
972 }
973
974 if (pid == -1) {
975 /*
976 * We are seriously hosed. Do our best.
977 */
978 emergency("can't fork single-user shell, trying again");
979 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
980 continue;
981 return (state_func_t) single_user;
982 }
983
984 requested_transition = 0;
985 do {
986 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
987 collect_child(wpid);
988 if (wpid == -1) {
989 if (errno == EINTR)
990 continue;
991 warning("wait for single-user shell failed: %m; restarting");
992 return (state_func_t) single_user;
993 }
994 if (wpid == pid && WIFSTOPPED(status)) {
995 warning("init: shell stopped, restarting\n");
996 kill(pid, SIGCONT);
997 wpid = -1;
998 }
999 } while (wpid != pid && !requested_transition);
1000
1001 if (requested_transition)
1002 return (state_func_t) requested_transition;
1003
1004 if (!WIFEXITED(status)) {
1005 if (WTERMSIG(status) == SIGKILL) {
1006 /*
1007 * reboot(8) killed shell?
1008 */
1009 warning("single user shell terminated.");
1010 sleep(STALL_TIMEOUT);
1011 _exit(0);
1012 } else {
1013 warning("single user shell terminated, restarting");
1014 return (state_func_t) single_user;
1015 }
1016 }
1017
1018 runcom_mode = FASTBOOT;
1019 return (state_func_t) runcom;
1020 }
1021
1022 /*
1023 * Run the system startup script.
1024 */
1025 static state_func_t
runcom(void)1026 runcom(void)
1027 {
1028 state_func_t next_transition;
1029
1030 if ((next_transition = run_script(_PATH_RUNCOM)) != 0)
1031 return next_transition;
1032
1033 runcom_mode = AUTOBOOT; /* the default */
1034 return (state_func_t) read_ttys;
1035 }
1036
1037 /*
1038 * Run a shell script.
1039 * Returns 0 on success, otherwise the next transition to enter:
1040 * - single_user if fork/execv/waitpid failed, or if the script
1041 * terminated with a signal or exit code != 0.
1042 * - death_single if a SIGTERM was delivered to init(8).
1043 */
1044 static state_func_t
run_script(const char * script)1045 run_script(const char *script)
1046 {
1047 pid_t pid, wpid;
1048 int status;
1049 char *argv[4];
1050 const char *shell;
1051 struct sigaction sa;
1052
1053 shell = get_shell();
1054
1055 if ((pid = fork()) == 0) {
1056 sigemptyset(&sa.sa_mask);
1057 sa.sa_flags = 0;
1058 sa.sa_handler = SIG_IGN;
1059 sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1060 sigaction(SIGHUP, &sa, (struct sigaction *)0);
1061
1062 open_console();
1063
1064 char _sh[] = "sh";
1065 char _autoboot[] = "autoboot";
1066
1067 argv[0] = _sh;
1068 argv[1] = __DECONST(char *, script);
1069 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0;
1070 argv[3] = 0;
1071
1072 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1073
1074 #ifdef LOGIN_CAP
1075 setprocresources(RESOURCE_RC);
1076 #endif
1077 execv(shell, argv);
1078 stall("can't exec %s for %s: %m", shell, script);
1079 _exit(1); /* force single user mode */
1080 }
1081
1082 if (pid == -1) {
1083 emergency("can't fork for %s on %s: %m", shell, script);
1084 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1085 continue;
1086 sleep(STALL_TIMEOUT);
1087 return (state_func_t) single_user;
1088 }
1089
1090 /*
1091 * Copied from single_user(). This is a bit paranoid.
1092 */
1093 requested_transition = 0;
1094 do {
1095 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1096 collect_child(wpid);
1097 if (wpid == -1) {
1098 if (requested_transition == death_single ||
1099 requested_transition == reroot)
1100 return (state_func_t) requested_transition;
1101 if (errno == EINTR)
1102 continue;
1103 warning("wait for %s on %s failed: %m; going to "
1104 "single user mode", shell, script);
1105 return (state_func_t) single_user;
1106 }
1107 if (wpid == pid && WIFSTOPPED(status)) {
1108 warning("init: %s on %s stopped, restarting\n",
1109 shell, script);
1110 kill(pid, SIGCONT);
1111 wpid = -1;
1112 }
1113 } while (wpid != pid);
1114
1115 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1116 requested_transition == catatonia) {
1117 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
1118 sigset_t s;
1119
1120 sigfillset(&s);
1121 for (;;)
1122 sigsuspend(&s);
1123 }
1124
1125 if (!WIFEXITED(status)) {
1126 warning("%s on %s terminated abnormally, going to single "
1127 "user mode", shell, script);
1128 return (state_func_t) single_user;
1129 }
1130
1131 if (WEXITSTATUS(status))
1132 return (state_func_t) single_user;
1133
1134 return (state_func_t) 0;
1135 }
1136
1137 /*
1138 * Open the session database.
1139 *
1140 * NB: We could pass in the size here; is it necessary?
1141 */
1142 static int
start_session_db(void)1143 start_session_db(void)
1144 {
1145 if (session_db && (*session_db->close)(session_db))
1146 emergency("session database close: %s", strerror(errno));
1147 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
1148 emergency("session database open: %s", strerror(errno));
1149 return (1);
1150 }
1151 return (0);
1152
1153 }
1154
1155 /*
1156 * Add a new login session.
1157 */
1158 static void
add_session(session_t * sp)1159 add_session(session_t *sp)
1160 {
1161 DBT key;
1162 DBT data;
1163
1164 key.data = &sp->se_process;
1165 key.size = sizeof sp->se_process;
1166 data.data = &sp;
1167 data.size = sizeof sp;
1168
1169 if ((*session_db->put)(session_db, &key, &data, 0))
1170 emergency("insert %d: %s", sp->se_process, strerror(errno));
1171 }
1172
1173 /*
1174 * Delete an old login session.
1175 */
1176 static void
del_session(session_t * sp)1177 del_session(session_t *sp)
1178 {
1179 DBT key;
1180
1181 key.data = &sp->se_process;
1182 key.size = sizeof sp->se_process;
1183
1184 if ((*session_db->del)(session_db, &key, 0))
1185 emergency("delete %d: %s", sp->se_process, strerror(errno));
1186 }
1187
1188 /*
1189 * Look up a login session by pid.
1190 */
1191 static session_t *
find_session(pid_t pid)1192 find_session(pid_t pid)
1193 {
1194 DBT key;
1195 DBT data;
1196 session_t *ret;
1197
1198 key.data = &pid;
1199 key.size = sizeof pid;
1200 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
1201 return 0;
1202 bcopy(data.data, (char *)&ret, sizeof(ret));
1203 return ret;
1204 }
1205
1206 /*
1207 * Construct an argument vector from a command line.
1208 */
1209 static char **
construct_argv(char * command)1210 construct_argv(char *command)
1211 {
1212 int argc = 0;
1213 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
1214 * sizeof (char *));
1215
1216 if ((argv[argc++] = strk(command)) == 0) {
1217 free(argv);
1218 return (NULL);
1219 }
1220 while ((argv[argc++] = strk((char *) 0)) != NULL)
1221 continue;
1222 return argv;
1223 }
1224
1225 /*
1226 * Deallocate a session descriptor.
1227 */
1228 static void
free_session(session_t * sp)1229 free_session(session_t *sp)
1230 {
1231 free(sp->se_device);
1232 if (sp->se_getty) {
1233 free(sp->se_getty);
1234 free(sp->se_getty_argv_space);
1235 free(sp->se_getty_argv);
1236 }
1237 if (sp->se_window) {
1238 free(sp->se_window);
1239 free(sp->se_window_argv_space);
1240 free(sp->se_window_argv);
1241 }
1242 if (sp->se_type)
1243 free(sp->se_type);
1244 free(sp);
1245 }
1246
1247 /*
1248 * Allocate a new session descriptor.
1249 * Mark it SE_PRESENT.
1250 */
1251 static session_t *
new_session(session_t * sprev,struct ttyent * typ)1252 new_session(session_t *sprev, struct ttyent *typ)
1253 {
1254 session_t *sp;
1255 int fd;
1256
1257 if ((typ->ty_status & TTY_ON) == 0 ||
1258 typ->ty_name == 0 ||
1259 typ->ty_getty == 0)
1260 return 0;
1261
1262 sp = (session_t *) calloc(1, sizeof (session_t));
1263
1264 sp->se_flags |= SE_PRESENT;
1265
1266 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
1267 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
1268
1269 /*
1270 * Attempt to open the device, if we get "device not configured"
1271 * then don't add the device to the session list.
1272 */
1273 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
1274 if (errno == ENXIO) {
1275 free_session(sp);
1276 return (0);
1277 }
1278 } else
1279 close(fd);
1280
1281 if (setupargv(sp, typ) == 0) {
1282 free_session(sp);
1283 return (0);
1284 }
1285
1286 sp->se_next = 0;
1287 if (sprev == 0) {
1288 sessions = sp;
1289 sp->se_prev = 0;
1290 } else {
1291 sprev->se_next = sp;
1292 sp->se_prev = sprev;
1293 }
1294
1295 return sp;
1296 }
1297
1298 /*
1299 * Calculate getty and if useful window argv vectors.
1300 */
1301 static int
setupargv(session_t * sp,struct ttyent * typ)1302 setupargv(session_t *sp, struct ttyent *typ)
1303 {
1304
1305 if (sp->se_getty) {
1306 free(sp->se_getty);
1307 free(sp->se_getty_argv_space);
1308 free(sp->se_getty_argv);
1309 }
1310 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1311 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1312 sp->se_getty_argv_space = strdup(sp->se_getty);
1313 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1314 if (sp->se_getty_argv == 0) {
1315 warning("can't parse getty for port %s", sp->se_device);
1316 free(sp->se_getty);
1317 free(sp->se_getty_argv_space);
1318 sp->se_getty = sp->se_getty_argv_space = 0;
1319 return (0);
1320 }
1321 if (sp->se_window) {
1322 free(sp->se_window);
1323 free(sp->se_window_argv_space);
1324 free(sp->se_window_argv);
1325 }
1326 sp->se_window = sp->se_window_argv_space = 0;
1327 sp->se_window_argv = 0;
1328 if (typ->ty_window) {
1329 sp->se_window = strdup(typ->ty_window);
1330 sp->se_window_argv_space = strdup(sp->se_window);
1331 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1332 if (sp->se_window_argv == 0) {
1333 warning("can't parse window for port %s",
1334 sp->se_device);
1335 free(sp->se_window_argv_space);
1336 free(sp->se_window);
1337 sp->se_window = sp->se_window_argv_space = 0;
1338 return (0);
1339 }
1340 }
1341 if (sp->se_type)
1342 free(sp->se_type);
1343 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1344 return (1);
1345 }
1346
1347 /*
1348 * Walk the list of ttys and create sessions for each active line.
1349 */
1350 static state_func_t
read_ttys(void)1351 read_ttys(void)
1352 {
1353 session_t *sp, *snext;
1354 struct ttyent *typ;
1355
1356 /*
1357 * Destroy any previous session state.
1358 * There shouldn't be any, but just in case...
1359 */
1360 for (sp = sessions; sp; sp = snext) {
1361 snext = sp->se_next;
1362 free_session(sp);
1363 }
1364 sessions = 0;
1365 if (start_session_db())
1366 return (state_func_t) single_user;
1367
1368 /*
1369 * Allocate a session entry for each active port.
1370 * Note that sp starts at 0.
1371 */
1372 while ((typ = getttyent()) != NULL)
1373 if ((snext = new_session(sp, typ)) != NULL)
1374 sp = snext;
1375
1376 endttyent();
1377
1378 return (state_func_t) multi_user;
1379 }
1380
1381 /*
1382 * Start a window system running.
1383 */
1384 static void
start_window_system(session_t * sp)1385 start_window_system(session_t *sp)
1386 {
1387 pid_t pid;
1388 sigset_t mask;
1389 char term[64], *env[2];
1390 int status;
1391
1392 if ((pid = fork()) == -1) {
1393 emergency("can't fork for window system on port %s: %m",
1394 sp->se_device);
1395 /* hope that getty fails and we can try again */
1396 return;
1397 }
1398 if (pid) {
1399 waitpid(-1, &status, 0);
1400 return;
1401 }
1402
1403 /* reparent window process to the init to not make a zombie on exit */
1404 if ((pid = fork()) == -1) {
1405 emergency("can't fork for window system on port %s: %m",
1406 sp->se_device);
1407 _exit(1);
1408 }
1409 if (pid)
1410 _exit(0);
1411
1412 sigemptyset(&mask);
1413 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1414
1415 if (setsid() < 0)
1416 emergency("setsid failed (window) %m");
1417
1418 #ifdef LOGIN_CAP
1419 setprocresources(RESOURCE_WINDOW);
1420 #endif
1421 if (sp->se_type) {
1422 /* Don't use malloc after fork */
1423 strcpy(term, "TERM=");
1424 strncat(term, sp->se_type, sizeof(term) - 6);
1425 env[0] = term;
1426 env[1] = 0;
1427 }
1428 else
1429 env[0] = 0;
1430 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1431 stall("can't exec window system '%s' for port %s: %m",
1432 sp->se_window_argv[0], sp->se_device);
1433 _exit(1);
1434 }
1435
1436 /*
1437 * Start a login session running.
1438 */
1439 static pid_t
start_getty(session_t * sp)1440 start_getty(session_t *sp)
1441 {
1442 pid_t pid;
1443 sigset_t mask;
1444 time_t current_time = time((time_t *) 0);
1445 int too_quick = 0;
1446 char term[64], *env[2];
1447
1448 if (current_time >= sp->se_started &&
1449 current_time - sp->se_started < GETTY_SPACING) {
1450 if (++sp->se_nspace > GETTY_NSPACE) {
1451 sp->se_nspace = 0;
1452 too_quick = 1;
1453 }
1454 } else
1455 sp->se_nspace = 0;
1456
1457 /*
1458 * fork(), not vfork() -- we can't afford to block.
1459 */
1460 if ((pid = fork()) == -1) {
1461 emergency("can't fork for getty on port %s: %m", sp->se_device);
1462 return -1;
1463 }
1464
1465 if (pid)
1466 return pid;
1467
1468 if (too_quick) {
1469 warning("getty repeating too quickly on port %s, sleeping %d secs",
1470 sp->se_device, GETTY_SLEEP);
1471 sleep((unsigned) GETTY_SLEEP);
1472 }
1473
1474 if (sp->se_window) {
1475 start_window_system(sp);
1476 sleep(WINDOW_WAIT);
1477 }
1478
1479 sigemptyset(&mask);
1480 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1481
1482 #ifdef LOGIN_CAP
1483 setprocresources(RESOURCE_GETTY);
1484 #endif
1485 if (sp->se_type) {
1486 /* Don't use malloc after fork */
1487 strcpy(term, "TERM=");
1488 strncat(term, sp->se_type, sizeof(term) - 6);
1489 env[0] = term;
1490 env[1] = 0;
1491 } else
1492 env[0] = 0;
1493 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1494 stall("can't exec getty '%s' for port %s: %m",
1495 sp->se_getty_argv[0], sp->se_device);
1496 _exit(1);
1497 }
1498
1499 /*
1500 * Collect exit status for a child.
1501 * If an exiting login, start a new login running.
1502 */
1503 static void
collect_child(pid_t pid)1504 collect_child(pid_t pid)
1505 {
1506 session_t *sp, *sprev, *snext;
1507
1508 if (! sessions)
1509 return;
1510
1511 if (! (sp = find_session(pid)))
1512 return;
1513
1514 del_session(sp);
1515 sp->se_process = 0;
1516
1517 if (sp->se_flags & SE_SHUTDOWN) {
1518 if ((sprev = sp->se_prev) != NULL)
1519 sprev->se_next = sp->se_next;
1520 else
1521 sessions = sp->se_next;
1522 if ((snext = sp->se_next) != NULL)
1523 snext->se_prev = sp->se_prev;
1524 free_session(sp);
1525 return;
1526 }
1527
1528 if ((pid = start_getty(sp)) == -1) {
1529 /* serious trouble */
1530 requested_transition = clean_ttys;
1531 return;
1532 }
1533
1534 sp->se_process = pid;
1535 sp->se_started = time((time_t *) 0);
1536 add_session(sp);
1537 }
1538
1539 /*
1540 * Catch a signal and request a state transition.
1541 */
1542 static void
transition_handler(int sig)1543 transition_handler(int sig)
1544 {
1545
1546 switch (sig) {
1547 case SIGHUP:
1548 if (current_state == read_ttys || current_state == multi_user ||
1549 current_state == clean_ttys || current_state == catatonia)
1550 requested_transition = clean_ttys;
1551 break;
1552 case SIGUSR2:
1553 howto = RB_POWEROFF;
1554 case SIGUSR1:
1555 howto |= RB_HALT;
1556 case SIGINT:
1557 Reboot = TRUE;
1558 case SIGTERM:
1559 if (current_state == read_ttys || current_state == multi_user ||
1560 current_state == clean_ttys || current_state == catatonia)
1561 requested_transition = death;
1562 else
1563 requested_transition = death_single;
1564 break;
1565 case SIGTSTP:
1566 if (current_state == runcom || current_state == read_ttys ||
1567 current_state == clean_ttys ||
1568 current_state == multi_user || current_state == catatonia)
1569 requested_transition = catatonia;
1570 break;
1571 case SIGEMT:
1572 requested_transition = reroot;
1573 break;
1574 default:
1575 requested_transition = 0;
1576 break;
1577 }
1578 }
1579
1580 /*
1581 * Take the system multiuser.
1582 */
1583 static state_func_t
multi_user(void)1584 multi_user(void)
1585 {
1586 pid_t pid;
1587 session_t *sp;
1588
1589 requested_transition = 0;
1590
1591 /*
1592 * If the administrator has not set the security level to -1
1593 * to indicate that the kernel should not run multiuser in secure
1594 * mode, and the run script has not set a higher level of security
1595 * than level 1, then put the kernel into secure mode.
1596 */
1597 if (getsecuritylevel() == 0)
1598 setsecuritylevel(1);
1599
1600 for (sp = sessions; sp; sp = sp->se_next) {
1601 if (sp->se_process)
1602 continue;
1603 if ((pid = start_getty(sp)) == -1) {
1604 /* serious trouble */
1605 requested_transition = clean_ttys;
1606 break;
1607 }
1608 sp->se_process = pid;
1609 sp->se_started = time((time_t *) 0);
1610 add_session(sp);
1611 }
1612
1613 while (!requested_transition)
1614 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1615 collect_child(pid);
1616
1617 return (state_func_t) requested_transition;
1618 }
1619
1620 /*
1621 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1622 */
1623 static state_func_t
clean_ttys(void)1624 clean_ttys(void)
1625 {
1626 session_t *sp, *sprev;
1627 struct ttyent *typ;
1628 int devlen;
1629 char *old_getty, *old_window, *old_type;
1630
1631 /*
1632 * mark all sessions for death, (!SE_PRESENT)
1633 * as we find or create new ones they'll be marked as keepers,
1634 * we'll later nuke all the ones not found in /etc/ttys
1635 */
1636 for (sp = sessions; sp != NULL; sp = sp->se_next)
1637 sp->se_flags &= ~SE_PRESENT;
1638
1639 devlen = sizeof(_PATH_DEV) - 1;
1640 while ((typ = getttyent()) != NULL) {
1641 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1642 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1643 break;
1644
1645 if (sp) {
1646 /* we want this one to live */
1647 sp->se_flags |= SE_PRESENT;
1648 if ((typ->ty_status & TTY_ON) == 0 ||
1649 typ->ty_getty == 0) {
1650 sp->se_flags |= SE_SHUTDOWN;
1651 kill(sp->se_process, SIGHUP);
1652 continue;
1653 }
1654 sp->se_flags &= ~SE_SHUTDOWN;
1655 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1656 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1657 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1658 if (setupargv(sp, typ) == 0) {
1659 warning("can't parse getty for port %s",
1660 sp->se_device);
1661 sp->se_flags |= SE_SHUTDOWN;
1662 kill(sp->se_process, SIGHUP);
1663 }
1664 else if ( !old_getty
1665 || (!old_type && sp->se_type)
1666 || (old_type && !sp->se_type)
1667 || (!old_window && sp->se_window)
1668 || (old_window && !sp->se_window)
1669 || (strcmp(old_getty, sp->se_getty) != 0)
1670 || (old_window && strcmp(old_window, sp->se_window) != 0)
1671 || (old_type && strcmp(old_type, sp->se_type) != 0)
1672 ) {
1673 /* Don't set SE_SHUTDOWN here */
1674 sp->se_nspace = 0;
1675 sp->se_started = 0;
1676 kill(sp->se_process, SIGHUP);
1677 }
1678 if (old_getty)
1679 free(old_getty);
1680 if (old_window)
1681 free(old_window);
1682 if (old_type)
1683 free(old_type);
1684 continue;
1685 }
1686
1687 new_session(sprev, typ);
1688 }
1689
1690 endttyent();
1691
1692 /*
1693 * sweep through and kill all deleted sessions
1694 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1695 */
1696 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1697 if ((sp->se_flags & SE_PRESENT) == 0) {
1698 sp->se_flags |= SE_SHUTDOWN;
1699 kill(sp->se_process, SIGHUP);
1700 }
1701 }
1702
1703 return (state_func_t) multi_user;
1704 }
1705
1706 /*
1707 * Block further logins.
1708 */
1709 static state_func_t
catatonia(void)1710 catatonia(void)
1711 {
1712 session_t *sp;
1713
1714 for (sp = sessions; sp; sp = sp->se_next)
1715 sp->se_flags |= SE_SHUTDOWN;
1716
1717 return (state_func_t) multi_user;
1718 }
1719
1720 /*
1721 * Note SIGALRM.
1722 */
1723 static void
alrm_handler(int sig)1724 alrm_handler(int sig)
1725 {
1726
1727 (void)sig;
1728 clang = 1;
1729 }
1730
1731 /*
1732 * Bring the system down to single user.
1733 */
1734 static state_func_t
death(void)1735 death(void)
1736 {
1737 int block, blocked;
1738 size_t len;
1739
1740 /* Temporarily block suspend. */
1741 len = sizeof(blocked);
1742 block = 1;
1743 if (sysctlbyname("kern.suspend_blocked", &blocked, &len,
1744 &block, sizeof(block)) == -1)
1745 blocked = 0;
1746
1747 /*
1748 * Also revoke the TTY here. Because runshutdown() may reopen
1749 * the TTY whose getty we're killing here, there is no guarantee
1750 * runshutdown() will perform the initial open() call, causing
1751 * the terminal attributes to be misconfigured.
1752 */
1753 revoke_ttys();
1754
1755 /* Try to run the rc.shutdown script within a period of time */
1756 runshutdown();
1757
1758 /* Unblock suspend if we blocked it. */
1759 if (!blocked)
1760 sysctlbyname("kern.suspend_blocked", NULL, NULL,
1761 &blocked, sizeof(blocked));
1762
1763 return (state_func_t) death_single;
1764 }
1765
1766 /*
1767 * Do what is necessary to reinitialize single user mode or reboot
1768 * from an incomplete state.
1769 */
1770 static state_func_t
death_single(void)1771 death_single(void)
1772 {
1773 int i;
1774 pid_t pid;
1775 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1776
1777 revoke(_PATH_CONSOLE);
1778
1779 for (i = 0; i < 2; ++i) {
1780 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1781 return (state_func_t) single_user;
1782
1783 clang = 0;
1784 alarm(DEATH_WATCH);
1785 do
1786 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1787 collect_child(pid);
1788 while (clang == 0 && errno != ECHILD);
1789
1790 if (errno == ECHILD)
1791 return (state_func_t) single_user;
1792 }
1793
1794 warning("some processes would not die; ps axl advised");
1795
1796 return (state_func_t) single_user;
1797 }
1798
1799 static void
revoke_ttys(void)1800 revoke_ttys(void)
1801 {
1802 session_t *sp;
1803
1804 for (sp = sessions; sp; sp = sp->se_next) {
1805 sp->se_flags |= SE_SHUTDOWN;
1806 kill(sp->se_process, SIGHUP);
1807 revoke(sp->se_device);
1808 }
1809 }
1810
1811 /*
1812 * Run the system shutdown script.
1813 *
1814 * Exit codes: XXX I should document more
1815 * -2 shutdown script terminated abnormally
1816 * -1 fatal error - can't run script
1817 * 0 good.
1818 * >0 some error (exit code)
1819 */
1820 static int
runshutdown(void)1821 runshutdown(void)
1822 {
1823 pid_t pid, wpid;
1824 int status;
1825 int shutdowntimeout;
1826 size_t len;
1827 char *argv[4];
1828 const char *shell;
1829 struct sigaction sa;
1830 struct stat sb;
1831
1832 /*
1833 * rc.shutdown is optional, so to prevent any unnecessary
1834 * complaints from the shell we simply don't run it if the
1835 * file does not exist. If the stat() here fails for other
1836 * reasons, we'll let the shell complain.
1837 */
1838 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1839 return 0;
1840
1841 shell = get_shell();
1842
1843 if ((pid = fork()) == 0) {
1844 sigemptyset(&sa.sa_mask);
1845 sa.sa_flags = 0;
1846 sa.sa_handler = SIG_IGN;
1847 sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1848 sigaction(SIGHUP, &sa, (struct sigaction *)0);
1849
1850 open_console();
1851
1852 char _sh[] = "sh";
1853 char _reboot[] = "reboot";
1854 char _single[] = "single";
1855 char _path_rundown[] = _PATH_RUNDOWN;
1856
1857 argv[0] = _sh;
1858 argv[1] = _path_rundown;
1859 argv[2] = Reboot ? _reboot : _single;
1860 argv[3] = 0;
1861
1862 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1863
1864 #ifdef LOGIN_CAP
1865 setprocresources(RESOURCE_RC);
1866 #endif
1867 execv(shell, argv);
1868 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN);
1869 _exit(1); /* force single user mode */
1870 }
1871
1872 if (pid == -1) {
1873 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN);
1874 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1875 continue;
1876 sleep(STALL_TIMEOUT);
1877 return -1;
1878 }
1879
1880 len = sizeof(shutdowntimeout);
1881 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
1882 NULL, 0) == -1 || shutdowntimeout < 2)
1883 shutdowntimeout = DEATH_SCRIPT;
1884 alarm(shutdowntimeout);
1885 clang = 0;
1886 /*
1887 * Copied from single_user(). This is a bit paranoid.
1888 * Use the same ALRM handler.
1889 */
1890 do {
1891 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1892 collect_child(wpid);
1893 if (clang == 1) {
1894 /* we were waiting for the sub-shell */
1895 kill(wpid, SIGTERM);
1896 warning("timeout expired for %s on %s: %m; going to "
1897 "single user mode", shell, _PATH_RUNDOWN);
1898 return -1;
1899 }
1900 if (wpid == -1) {
1901 if (errno == EINTR)
1902 continue;
1903 warning("wait for %s on %s failed: %m; going to "
1904 "single user mode", shell, _PATH_RUNDOWN);
1905 return -1;
1906 }
1907 if (wpid == pid && WIFSTOPPED(status)) {
1908 warning("init: %s on %s stopped, restarting\n",
1909 shell, _PATH_RUNDOWN);
1910 kill(pid, SIGCONT);
1911 wpid = -1;
1912 }
1913 } while (wpid != pid && !clang);
1914
1915 /* Turn off the alarm */
1916 alarm(0);
1917
1918 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1919 requested_transition == catatonia) {
1920 /*
1921 * /etc/rc.shutdown executed /sbin/reboot;
1922 * wait for the end quietly
1923 */
1924 sigset_t s;
1925
1926 sigfillset(&s);
1927 for (;;)
1928 sigsuspend(&s);
1929 }
1930
1931 if (!WIFEXITED(status)) {
1932 warning("%s on %s terminated abnormally, going to "
1933 "single user mode", shell, _PATH_RUNDOWN);
1934 return -2;
1935 }
1936
1937 if ((status = WEXITSTATUS(status)) != 0)
1938 warning("%s returned status %d", _PATH_RUNDOWN, status);
1939
1940 return status;
1941 }
1942
1943 static char *
strk(char * p)1944 strk(char *p)
1945 {
1946 static char *t;
1947 char *q;
1948 int c;
1949
1950 if (p)
1951 t = p;
1952 if (!t)
1953 return 0;
1954
1955 c = *t;
1956 while (c == ' ' || c == '\t' )
1957 c = *++t;
1958 if (!c) {
1959 t = 0;
1960 return 0;
1961 }
1962 q = t;
1963 if (c == '\'') {
1964 c = *++t;
1965 q = t;
1966 while (c && c != '\'')
1967 c = *++t;
1968 if (!c) /* unterminated string */
1969 q = t = 0;
1970 else
1971 *t++ = 0;
1972 } else {
1973 while (c && c != ' ' && c != '\t' )
1974 c = *++t;
1975 *t++ = 0;
1976 if (!c)
1977 t = 0;
1978 }
1979 return q;
1980 }
1981
1982 #ifdef LOGIN_CAP
1983 static void
setprocresources(const char * cname)1984 setprocresources(const char *cname)
1985 {
1986 login_cap_t *lc;
1987 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1988 setusercontext(lc, (struct passwd*)NULL, 0,
1989 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
1990 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
1991 login_close(lc);
1992 }
1993 }
1994 #endif
1995