1 /*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Donn Seeley at Berkeley Software Design, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1991, 1993\n\
36 The Regents of the University of California. All rights reserved.\n";
37 #endif /* not lint */
38
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93";
42 #endif
43 static const char rcsid[] =
44 "$FreeBSD$";
45 #endif /* not lint */
46
47 #include <sys/param.h>
48 #include <sys/ioctl.h>
49 #include <sys/mount.h>
50 #include <sys/sysctl.h>
51 #include <sys/wait.h>
52 #include <sys/stat.h>
53 #include <sys/uio.h>
54
55 #include <db.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <kenv.h>
59 #include <libutil.h>
60 #include <paths.h>
61 #include <signal.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include <syslog.h>
66 #include <time.h>
67 #include <ttyent.h>
68 #include <unistd.h>
69 #include <sys/reboot.h>
70 #include <err.h>
71
72 #include <stdarg.h>
73
74 #ifdef SECURE
75 #include <pwd.h>
76 #endif
77
78 #ifdef LOGIN_CAP
79 #include <login_cap.h>
80 #endif
81
82 #include "pathnames.h"
83
84 /*
85 * Sleep times; used to prevent thrashing.
86 */
87 #define GETTY_SPACING 5 /* N secs minimum getty spacing */
88 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */
89 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */
90 #define WINDOW_WAIT 3 /* wait N secs after starting window */
91 #define STALL_TIMEOUT 30 /* wait N secs after warning */
92 #define DEATH_WATCH 10 /* wait N secs for procs to die */
93 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */
94 #define RESOURCE_RC "daemon"
95 #define RESOURCE_WINDOW "default"
96 #define RESOURCE_GETTY "default"
97
98 static void handle(sig_t, ...);
99 static void delset(sigset_t *, ...);
100
101 static void stall(const char *, ...) __printflike(1, 2);
102 static void warning(const char *, ...) __printflike(1, 2);
103 static void emergency(const char *, ...) __printflike(1, 2);
104 static void disaster(int);
105 static void badsys(int);
106 static int runshutdown(void);
107 static char *strk(char *);
108
109 /*
110 * We really need a recursive typedef...
111 * The following at least guarantees that the return type of (*state_t)()
112 * is sufficiently wide to hold a function pointer.
113 */
114 typedef long (*state_func_t)(void);
115 typedef state_func_t (*state_t)(void);
116
117 static state_func_t single_user(void);
118 static state_func_t runcom(void);
119 static state_func_t read_ttys(void);
120 static state_func_t multi_user(void);
121 static state_func_t clean_ttys(void);
122 static state_func_t catatonia(void);
123 static state_func_t death(void);
124 static state_func_t death_single(void);
125
126 static state_func_t run_script(const char *);
127
128 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
129 #define FALSE 0
130 #define TRUE 1
131
132 static int Reboot = FALSE;
133 static int howto = RB_AUTOBOOT;
134
135 static int devfs;
136
137 static void transition(state_t);
138 static state_t requested_transition;
139 static state_t current_state = death_single;
140
141 static void open_console(void);
142 static const char *get_shell(void);
143 static void write_stderr(const char *message);
144
145 typedef struct init_session {
146 int se_index; /* index of entry in ttys file */
147 pid_t se_process; /* controlling process */
148 time_t se_started; /* used to avoid thrashing */
149 int se_flags; /* status of session */
150 #define SE_SHUTDOWN 0x1 /* session won't be restarted */
151 #define SE_PRESENT 0x2 /* session is in /etc/ttys */
152 int se_nspace; /* spacing count */
153 char *se_device; /* filename of port */
154 char *se_getty; /* what to run on that port */
155 char *se_getty_argv_space; /* pre-parsed argument array space */
156 char **se_getty_argv; /* pre-parsed argument array */
157 char *se_window; /* window system (started only once) */
158 char *se_window_argv_space; /* pre-parsed argument array space */
159 char **se_window_argv; /* pre-parsed argument array */
160 char *se_type; /* default terminal type */
161 struct init_session *se_prev;
162 struct init_session *se_next;
163 } session_t;
164
165 static void free_session(session_t *);
166 static session_t *new_session(session_t *, int, struct ttyent *);
167 static session_t *sessions;
168
169 static char **construct_argv(char *);
170 static void start_window_system(session_t *);
171 static void collect_child(pid_t);
172 static pid_t start_getty(session_t *);
173 static void transition_handler(int);
174 static void alrm_handler(int);
175 static void setsecuritylevel(int);
176 static int getsecuritylevel(void);
177 static int setupargv(session_t *, struct ttyent *);
178 #ifdef LOGIN_CAP
179 static void setprocresources(const char *);
180 #endif
181 static int clang;
182
183 static int start_session_db(void);
184 static void add_session(session_t *);
185 static void del_session(session_t *);
186 static session_t *find_session(pid_t);
187 static DB *session_db;
188
189 /*
190 * The mother of all processes.
191 */
192 int
main(int argc,char * argv[])193 main(int argc, char *argv[])
194 {
195 state_t initial_transition = runcom;
196 char kenv_value[PATH_MAX];
197 int c;
198 struct sigaction sa;
199 sigset_t mask;
200
201 /* Dispose of random users. */
202 if (getuid() != 0)
203 errx(1, "%s", strerror(EPERM));
204
205 /* System V users like to reexec init. */
206 if (getpid() != 1) {
207 #ifdef COMPAT_SYSV_INIT
208 /* So give them what they want */
209 if (argc > 1) {
210 if (strlen(argv[1]) == 1) {
211 char runlevel = *argv[1];
212 int sig;
213
214 switch (runlevel) {
215 case '0': /* halt + poweroff */
216 sig = SIGUSR2;
217 break;
218 case '1': /* single-user */
219 sig = SIGTERM;
220 break;
221 case '6': /* reboot */
222 sig = SIGINT;
223 break;
224 case 'c': /* block further logins */
225 sig = SIGTSTP;
226 break;
227 case 'q': /* rescan /etc/ttys */
228 sig = SIGHUP;
229 break;
230 default:
231 goto invalid;
232 }
233 kill(1, sig);
234 _exit(0);
235 } else
236 invalid:
237 errx(1, "invalid run-level ``%s''", argv[1]);
238 } else
239 #endif
240 errx(1, "already running");
241 }
242 /*
243 * Note that this does NOT open a file...
244 * Does 'init' deserve its own facility number?
245 */
246 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
247
248 /*
249 * Create an initial session.
250 */
251 if (setsid() < 0)
252 warning("initial setsid() failed: %m");
253
254 /*
255 * Establish an initial user so that programs running
256 * single user do not freak out and die (like passwd).
257 */
258 if (setlogin("root") < 0)
259 warning("setlogin() failed: %m");
260
261 /*
262 * This code assumes that we always get arguments through flags,
263 * never through bits set in some random machine register.
264 */
265 while ((c = getopt(argc, argv, "dsf")) != -1)
266 switch (c) {
267 case 'd':
268 devfs = 1;
269 break;
270 case 's':
271 initial_transition = single_user;
272 break;
273 case 'f':
274 runcom_mode = FASTBOOT;
275 break;
276 default:
277 warning("unrecognized flag '-%c'", c);
278 break;
279 }
280
281 if (optind != argc)
282 warning("ignoring excess arguments");
283
284 /*
285 * We catch or block signals rather than ignore them,
286 * so that they get reset on exec.
287 */
288 handle(badsys, SIGSYS, 0);
289 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU,
290 SIGXFSZ, 0);
291 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGUSR1,
292 SIGUSR2, 0);
293 handle(alrm_handler, SIGALRM, 0);
294 sigfillset(&mask);
295 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
296 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
297 SIGUSR1, SIGUSR2, 0);
298 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
299 sigemptyset(&sa.sa_mask);
300 sa.sa_flags = 0;
301 sa.sa_handler = SIG_IGN;
302 sigaction(SIGTTIN, &sa, (struct sigaction *)0);
303 sigaction(SIGTTOU, &sa, (struct sigaction *)0);
304
305 /*
306 * Paranoia.
307 */
308 close(0);
309 close(1);
310 close(2);
311
312 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
313 state_func_t next_transition;
314
315 if ((next_transition = run_script(kenv_value)) != 0)
316 initial_transition = (state_t) next_transition;
317 }
318
319 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
320 if (chdir(kenv_value) != 0 || chroot(".") != 0)
321 warning("Can't chroot to %s: %m", kenv_value);
322 }
323
324 /*
325 * Additional check if devfs needs to be mounted:
326 * If "/" and "/dev" have the same device number,
327 * then it hasn't been mounted yet.
328 */
329 if (!devfs) {
330 struct stat stst;
331 dev_t root_devno;
332
333 stat("/", &stst);
334 root_devno = stst.st_dev;
335 if (stat("/dev", &stst) != 0)
336 warning("Can't stat /dev: %m");
337 else if (stst.st_dev == root_devno)
338 devfs++;
339 }
340
341 if (devfs) {
342 struct iovec iov[4];
343 char *s;
344 int i;
345
346 char _fstype[] = "fstype";
347 char _devfs[] = "devfs";
348 char _fspath[] = "fspath";
349 char _path_dev[]= _PATH_DEV;
350
351 iov[0].iov_base = _fstype;
352 iov[0].iov_len = sizeof(_fstype);
353 iov[1].iov_base = _devfs;
354 iov[1].iov_len = sizeof(_devfs);
355 iov[2].iov_base = _fspath;
356 iov[2].iov_len = sizeof(_fspath);
357 /*
358 * Try to avoid the trailing slash in _PATH_DEV.
359 * Be *very* defensive.
360 */
361 s = strdup(_PATH_DEV);
362 if (s != NULL) {
363 i = strlen(s);
364 if (i > 0 && s[i - 1] == '/')
365 s[i - 1] = '\0';
366 iov[3].iov_base = s;
367 iov[3].iov_len = strlen(s) + 1;
368 } else {
369 iov[3].iov_base = _path_dev;
370 iov[3].iov_len = sizeof(_path_dev);
371 }
372 nmount(iov, 4, 0);
373 if (s != NULL)
374 free(s);
375 }
376
377 /*
378 * Start the state machine.
379 */
380 transition(initial_transition);
381
382 /*
383 * Should never reach here.
384 */
385 return 1;
386 }
387
388 /*
389 * Associate a function with a signal handler.
390 */
391 static void
handle(sig_t handler,...)392 handle(sig_t handler, ...)
393 {
394 int sig;
395 struct sigaction sa;
396 sigset_t mask_everything;
397 va_list ap;
398 va_start(ap, handler);
399
400 sa.sa_handler = handler;
401 sigfillset(&mask_everything);
402
403 while ((sig = va_arg(ap, int)) != 0) {
404 sa.sa_mask = mask_everything;
405 /* XXX SA_RESTART? */
406 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
407 sigaction(sig, &sa, (struct sigaction *) 0);
408 }
409 va_end(ap);
410 }
411
412 /*
413 * Delete a set of signals from a mask.
414 */
415 static void
delset(sigset_t * maskp,...)416 delset(sigset_t *maskp, ...)
417 {
418 int sig;
419 va_list ap;
420 va_start(ap, maskp);
421
422 while ((sig = va_arg(ap, int)) != 0)
423 sigdelset(maskp, sig);
424 va_end(ap);
425 }
426
427 /*
428 * Log a message and sleep for a while (to give someone an opportunity
429 * to read it and to save log or hardcopy output if the problem is chronic).
430 * NB: should send a message to the session logger to avoid blocking.
431 */
432 static void
stall(const char * message,...)433 stall(const char *message, ...)
434 {
435 va_list ap;
436 va_start(ap, message);
437
438 vsyslog(LOG_ALERT, message, ap);
439 va_end(ap);
440 sleep(STALL_TIMEOUT);
441 }
442
443 /*
444 * Like stall(), but doesn't sleep.
445 * If cpp had variadic macros, the two functions could be #defines for another.
446 * NB: should send a message to the session logger to avoid blocking.
447 */
448 static void
warning(const char * message,...)449 warning(const char *message, ...)
450 {
451 va_list ap;
452 va_start(ap, message);
453
454 vsyslog(LOG_ALERT, message, ap);
455 va_end(ap);
456 }
457
458 /*
459 * Log an emergency message.
460 * NB: should send a message to the session logger to avoid blocking.
461 */
462 static void
emergency(const char * message,...)463 emergency(const char *message, ...)
464 {
465 va_list ap;
466 va_start(ap, message);
467
468 vsyslog(LOG_EMERG, message, ap);
469 va_end(ap);
470 }
471
472 /*
473 * Catch a SIGSYS signal.
474 *
475 * These may arise if a system does not support sysctl.
476 * We tolerate up to 25 of these, then throw in the towel.
477 */
478 static void
badsys(int sig)479 badsys(int sig)
480 {
481 static int badcount = 0;
482
483 if (badcount++ < 25)
484 return;
485 disaster(sig);
486 }
487
488 /*
489 * Catch an unexpected signal.
490 */
491 static void
disaster(int sig)492 disaster(int sig)
493 {
494
495 emergency("fatal signal: %s",
496 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
497
498 sleep(STALL_TIMEOUT);
499 _exit(sig); /* reboot */
500 }
501
502 /*
503 * Get the security level of the kernel.
504 */
505 static int
getsecuritylevel(void)506 getsecuritylevel(void)
507 {
508 #ifdef KERN_SECURELVL
509 int name[2], curlevel;
510 size_t len;
511
512 name[0] = CTL_KERN;
513 name[1] = KERN_SECURELVL;
514 len = sizeof curlevel;
515 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
516 emergency("cannot get kernel security level: %s",
517 strerror(errno));
518 return (-1);
519 }
520 return (curlevel);
521 #else
522 return (-1);
523 #endif
524 }
525
526 /*
527 * Set the security level of the kernel.
528 */
529 static void
setsecuritylevel(int newlevel)530 setsecuritylevel(int newlevel)
531 {
532 #ifdef KERN_SECURELVL
533 int name[2], curlevel;
534
535 curlevel = getsecuritylevel();
536 if (newlevel == curlevel)
537 return;
538 name[0] = CTL_KERN;
539 name[1] = KERN_SECURELVL;
540 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
541 emergency(
542 "cannot change kernel security level from %d to %d: %s",
543 curlevel, newlevel, strerror(errno));
544 return;
545 }
546 #ifdef SECURE
547 warning("kernel security level changed from %d to %d",
548 curlevel, newlevel);
549 #endif
550 #endif
551 }
552
553 /*
554 * Change states in the finite state machine.
555 * The initial state is passed as an argument.
556 */
557 static void
transition(state_t s)558 transition(state_t s)
559 {
560
561 current_state = s;
562 for (;;)
563 current_state = (state_t) (*current_state)();
564 }
565
566 /*
567 * Start a session and allocate a controlling terminal.
568 * Only called by children of init after forking.
569 */
570 static void
open_console(void)571 open_console(void)
572 {
573 int fd;
574
575 /*
576 * Try to open /dev/console. Open the device with O_NONBLOCK to
577 * prevent potential blocking on a carrier.
578 */
579 revoke(_PATH_CONSOLE);
580 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) {
581 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
582 if (login_tty(fd) == 0)
583 return;
584 close(fd);
585 }
586
587 /* No luck. Log output to file if possible. */
588 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
589 stall("cannot open null device.");
590 _exit(1);
591 }
592 if (fd != STDIN_FILENO) {
593 dup2(fd, STDIN_FILENO);
594 close(fd);
595 }
596 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644);
597 if (fd == -1)
598 dup2(STDIN_FILENO, STDOUT_FILENO);
599 else if (fd != STDOUT_FILENO) {
600 dup2(fd, STDOUT_FILENO);
601 close(fd);
602 }
603 dup2(STDOUT_FILENO, STDERR_FILENO);
604 }
605
606 static const char *
get_shell(void)607 get_shell(void)
608 {
609 static char kenv_value[PATH_MAX];
610
611 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
612 return kenv_value;
613 else
614 return _PATH_BSHELL;
615 }
616
617 static void
write_stderr(const char * message)618 write_stderr(const char *message)
619 {
620
621 write(STDERR_FILENO, message, strlen(message));
622 }
623
624 /*
625 * Bring the system up single user.
626 */
627 static state_func_t
single_user(void)628 single_user(void)
629 {
630 pid_t pid, wpid;
631 int status;
632 sigset_t mask;
633 const char *shell;
634 char *argv[2];
635 #ifdef SECURE
636 struct ttyent *typ;
637 struct passwd *pp;
638 static const char banner[] =
639 "Enter root password, or ^D to go multi-user\n";
640 char *clear, *password;
641 #endif
642 #ifdef DEBUGSHELL
643 char altshell[128];
644 #endif
645
646 if (Reboot) {
647 /* Instead of going single user, let's reboot the machine */
648 sync();
649 reboot(howto);
650 _exit(0);
651 }
652
653 shell = get_shell();
654
655 if ((pid = fork()) == 0) {
656 /*
657 * Start the single user session.
658 */
659 open_console();
660
661 #ifdef SECURE
662 /*
663 * Check the root password.
664 * We don't care if the console is 'on' by default;
665 * it's the only tty that can be 'off' and 'secure'.
666 */
667 typ = getttynam("console");
668 pp = getpwnam("root");
669 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
670 pp && *pp->pw_passwd) {
671 write_stderr(banner);
672 for (;;) {
673 clear = getpass("Password:");
674 if (clear == 0 || *clear == '\0')
675 _exit(0);
676 password = crypt(clear, pp->pw_passwd);
677 bzero(clear, _PASSWORD_LEN);
678 if (password == NULL ||
679 strcmp(password, pp->pw_passwd) == 0)
680 break;
681 warning("single-user login failed\n");
682 }
683 }
684 endttyent();
685 endpwent();
686 #endif /* SECURE */
687
688 #ifdef DEBUGSHELL
689 {
690 char *cp = altshell;
691 int num;
692
693 #define SHREQUEST "Enter full pathname of shell or RETURN for "
694 write_stderr(SHREQUEST);
695 write_stderr(shell);
696 write_stderr(": ");
697 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
698 num != 0 && *cp != '\n' && cp < &altshell[127])
699 cp++;
700 *cp = '\0';
701 if (altshell[0] != '\0')
702 shell = altshell;
703 }
704 #endif /* DEBUGSHELL */
705
706 /*
707 * Unblock signals.
708 * We catch all the interesting ones,
709 * and those are reset to SIG_DFL on exec.
710 */
711 sigemptyset(&mask);
712 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
713
714 /*
715 * Fire off a shell.
716 * If the default one doesn't work, try the Bourne shell.
717 */
718
719 char name[] = "-sh";
720
721 argv[0] = name;
722 argv[1] = 0;
723 execv(shell, argv);
724 emergency("can't exec %s for single user: %m", shell);
725 execv(_PATH_BSHELL, argv);
726 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
727 sleep(STALL_TIMEOUT);
728 _exit(1);
729 }
730
731 if (pid == -1) {
732 /*
733 * We are seriously hosed. Do our best.
734 */
735 emergency("can't fork single-user shell, trying again");
736 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
737 continue;
738 return (state_func_t) single_user;
739 }
740
741 requested_transition = 0;
742 do {
743 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
744 collect_child(wpid);
745 if (wpid == -1) {
746 if (errno == EINTR)
747 continue;
748 warning("wait for single-user shell failed: %m; restarting");
749 return (state_func_t) single_user;
750 }
751 if (wpid == pid && WIFSTOPPED(status)) {
752 warning("init: shell stopped, restarting\n");
753 kill(pid, SIGCONT);
754 wpid = -1;
755 }
756 } while (wpid != pid && !requested_transition);
757
758 if (requested_transition)
759 return (state_func_t) requested_transition;
760
761 if (!WIFEXITED(status)) {
762 if (WTERMSIG(status) == SIGKILL) {
763 /*
764 * reboot(8) killed shell?
765 */
766 warning("single user shell terminated.");
767 sleep(STALL_TIMEOUT);
768 _exit(0);
769 } else {
770 warning("single user shell terminated, restarting");
771 return (state_func_t) single_user;
772 }
773 }
774
775 runcom_mode = FASTBOOT;
776 return (state_func_t) runcom;
777 }
778
779 /*
780 * Run the system startup script.
781 */
782 static state_func_t
runcom(void)783 runcom(void)
784 {
785 state_func_t next_transition;
786
787 if ((next_transition = run_script(_PATH_RUNCOM)) != 0)
788 return next_transition;
789
790 runcom_mode = AUTOBOOT; /* the default */
791 return (state_func_t) read_ttys;
792 }
793
794 /*
795 * Run a shell script.
796 * Returns 0 on success, otherwise the next transition to enter:
797 * - single_user if fork/execv/waitpid failed, or if the script
798 * terminated with a signal or exit code != 0.
799 * - death_single if a SIGTERM was delivered to init(8).
800 */
801 static state_func_t
run_script(const char * script)802 run_script(const char *script)
803 {
804 pid_t pid, wpid;
805 int status;
806 char *argv[4];
807 const char *shell;
808 struct sigaction sa;
809
810 shell = get_shell();
811
812 if ((pid = fork()) == 0) {
813 sigemptyset(&sa.sa_mask);
814 sa.sa_flags = 0;
815 sa.sa_handler = SIG_IGN;
816 sigaction(SIGTSTP, &sa, (struct sigaction *)0);
817 sigaction(SIGHUP, &sa, (struct sigaction *)0);
818
819 open_console();
820
821 char _sh[] = "sh";
822 char _autoboot[] = "autoboot";
823
824 argv[0] = _sh;
825 argv[1] = __DECONST(char *, script);
826 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0;
827 argv[3] = 0;
828
829 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
830
831 #ifdef LOGIN_CAP
832 setprocresources(RESOURCE_RC);
833 #endif
834 execv(shell, argv);
835 stall("can't exec %s for %s: %m", shell, script);
836 _exit(1); /* force single user mode */
837 }
838
839 if (pid == -1) {
840 emergency("can't fork for %s on %s: %m", shell, script);
841 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
842 continue;
843 sleep(STALL_TIMEOUT);
844 return (state_func_t) single_user;
845 }
846
847 /*
848 * Copied from single_user(). This is a bit paranoid.
849 */
850 requested_transition = 0;
851 do {
852 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
853 collect_child(wpid);
854 if (wpid == -1) {
855 if (requested_transition == death_single)
856 return (state_func_t) death_single;
857 if (errno == EINTR)
858 continue;
859 warning("wait for %s on %s failed: %m; going to "
860 "single user mode", shell, script);
861 return (state_func_t) single_user;
862 }
863 if (wpid == pid && WIFSTOPPED(status)) {
864 warning("init: %s on %s stopped, restarting\n",
865 shell, script);
866 kill(pid, SIGCONT);
867 wpid = -1;
868 }
869 } while (wpid != pid);
870
871 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
872 requested_transition == catatonia) {
873 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
874 sigset_t s;
875
876 sigfillset(&s);
877 for (;;)
878 sigsuspend(&s);
879 }
880
881 if (!WIFEXITED(status)) {
882 warning("%s on %s terminated abnormally, going to single "
883 "user mode", shell, script);
884 return (state_func_t) single_user;
885 }
886
887 if (WEXITSTATUS(status))
888 return (state_func_t) single_user;
889
890 return (state_func_t) 0;
891 }
892
893 /*
894 * Open the session database.
895 *
896 * NB: We could pass in the size here; is it necessary?
897 */
898 static int
start_session_db(void)899 start_session_db(void)
900 {
901 if (session_db && (*session_db->close)(session_db))
902 emergency("session database close: %s", strerror(errno));
903 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
904 emergency("session database open: %s", strerror(errno));
905 return (1);
906 }
907 return (0);
908
909 }
910
911 /*
912 * Add a new login session.
913 */
914 static void
add_session(session_t * sp)915 add_session(session_t *sp)
916 {
917 DBT key;
918 DBT data;
919
920 key.data = &sp->se_process;
921 key.size = sizeof sp->se_process;
922 data.data = &sp;
923 data.size = sizeof sp;
924
925 if ((*session_db->put)(session_db, &key, &data, 0))
926 emergency("insert %d: %s", sp->se_process, strerror(errno));
927 }
928
929 /*
930 * Delete an old login session.
931 */
932 static void
del_session(session_t * sp)933 del_session(session_t *sp)
934 {
935 DBT key;
936
937 key.data = &sp->se_process;
938 key.size = sizeof sp->se_process;
939
940 if ((*session_db->del)(session_db, &key, 0))
941 emergency("delete %d: %s", sp->se_process, strerror(errno));
942 }
943
944 /*
945 * Look up a login session by pid.
946 */
947 static session_t *
find_session(pid_t pid)948 find_session(pid_t pid)
949 {
950 DBT key;
951 DBT data;
952 session_t *ret;
953
954 key.data = &pid;
955 key.size = sizeof pid;
956 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
957 return 0;
958 bcopy(data.data, (char *)&ret, sizeof(ret));
959 return ret;
960 }
961
962 /*
963 * Construct an argument vector from a command line.
964 */
965 static char **
construct_argv(char * command)966 construct_argv(char *command)
967 {
968 int argc = 0;
969 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
970 * sizeof (char *));
971
972 if ((argv[argc++] = strk(command)) == 0) {
973 free(argv);
974 return (NULL);
975 }
976 while ((argv[argc++] = strk((char *) 0)) != NULL)
977 continue;
978 return argv;
979 }
980
981 /*
982 * Deallocate a session descriptor.
983 */
984 static void
free_session(session_t * sp)985 free_session(session_t *sp)
986 {
987 free(sp->se_device);
988 if (sp->se_getty) {
989 free(sp->se_getty);
990 free(sp->se_getty_argv_space);
991 free(sp->se_getty_argv);
992 }
993 if (sp->se_window) {
994 free(sp->se_window);
995 free(sp->se_window_argv_space);
996 free(sp->se_window_argv);
997 }
998 if (sp->se_type)
999 free(sp->se_type);
1000 free(sp);
1001 }
1002
1003 /*
1004 * Allocate a new session descriptor.
1005 * Mark it SE_PRESENT.
1006 */
1007 static session_t *
new_session(session_t * sprev,int session_index,struct ttyent * typ)1008 new_session(session_t *sprev, int session_index, struct ttyent *typ)
1009 {
1010 session_t *sp;
1011 int fd;
1012
1013 if ((typ->ty_status & TTY_ON) == 0 ||
1014 typ->ty_name == 0 ||
1015 typ->ty_getty == 0)
1016 return 0;
1017
1018 sp = (session_t *) calloc(1, sizeof (session_t));
1019
1020 sp->se_index = session_index;
1021 sp->se_flags |= SE_PRESENT;
1022
1023 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
1024 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
1025
1026 /*
1027 * Attempt to open the device, if we get "device not configured"
1028 * then don't add the device to the session list.
1029 */
1030 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
1031 if (errno == ENXIO) {
1032 free_session(sp);
1033 return (0);
1034 }
1035 } else
1036 close(fd);
1037
1038 if (setupargv(sp, typ) == 0) {
1039 free_session(sp);
1040 return (0);
1041 }
1042
1043 sp->se_next = 0;
1044 if (sprev == 0) {
1045 sessions = sp;
1046 sp->se_prev = 0;
1047 } else {
1048 sprev->se_next = sp;
1049 sp->se_prev = sprev;
1050 }
1051
1052 return sp;
1053 }
1054
1055 /*
1056 * Calculate getty and if useful window argv vectors.
1057 */
1058 static int
setupargv(session_t * sp,struct ttyent * typ)1059 setupargv(session_t *sp, struct ttyent *typ)
1060 {
1061
1062 if (sp->se_getty) {
1063 free(sp->se_getty);
1064 free(sp->se_getty_argv_space);
1065 free(sp->se_getty_argv);
1066 }
1067 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1068 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1069 sp->se_getty_argv_space = strdup(sp->se_getty);
1070 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1071 if (sp->se_getty_argv == 0) {
1072 warning("can't parse getty for port %s", sp->se_device);
1073 free(sp->se_getty);
1074 free(sp->se_getty_argv_space);
1075 sp->se_getty = sp->se_getty_argv_space = 0;
1076 return (0);
1077 }
1078 if (sp->se_window) {
1079 free(sp->se_window);
1080 free(sp->se_window_argv_space);
1081 free(sp->se_window_argv);
1082 }
1083 sp->se_window = sp->se_window_argv_space = 0;
1084 sp->se_window_argv = 0;
1085 if (typ->ty_window) {
1086 sp->se_window = strdup(typ->ty_window);
1087 sp->se_window_argv_space = strdup(sp->se_window);
1088 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1089 if (sp->se_window_argv == 0) {
1090 warning("can't parse window for port %s",
1091 sp->se_device);
1092 free(sp->se_window_argv_space);
1093 free(sp->se_window);
1094 sp->se_window = sp->se_window_argv_space = 0;
1095 return (0);
1096 }
1097 }
1098 if (sp->se_type)
1099 free(sp->se_type);
1100 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1101 return (1);
1102 }
1103
1104 /*
1105 * Walk the list of ttys and create sessions for each active line.
1106 */
1107 static state_func_t
read_ttys(void)1108 read_ttys(void)
1109 {
1110 int session_index = 0;
1111 session_t *sp, *snext;
1112 struct ttyent *typ;
1113
1114 /*
1115 * Destroy any previous session state.
1116 * There shouldn't be any, but just in case...
1117 */
1118 for (sp = sessions; sp; sp = snext) {
1119 snext = sp->se_next;
1120 free_session(sp);
1121 }
1122 sessions = 0;
1123 if (start_session_db())
1124 return (state_func_t) single_user;
1125
1126 /*
1127 * Allocate a session entry for each active port.
1128 * Note that sp starts at 0.
1129 */
1130 while ((typ = getttyent()) != NULL)
1131 if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1132 sp = snext;
1133
1134 endttyent();
1135
1136 return (state_func_t) multi_user;
1137 }
1138
1139 /*
1140 * Start a window system running.
1141 */
1142 static void
start_window_system(session_t * sp)1143 start_window_system(session_t *sp)
1144 {
1145 pid_t pid;
1146 sigset_t mask;
1147 char term[64], *env[2];
1148 int status;
1149
1150 if ((pid = fork()) == -1) {
1151 emergency("can't fork for window system on port %s: %m",
1152 sp->se_device);
1153 /* hope that getty fails and we can try again */
1154 return;
1155 }
1156 if (pid) {
1157 waitpid(-1, &status, 0);
1158 return;
1159 }
1160
1161 /* reparent window process to the init to not make a zombie on exit */
1162 if ((pid = fork()) == -1) {
1163 emergency("can't fork for window system on port %s: %m",
1164 sp->se_device);
1165 _exit(1);
1166 }
1167 if (pid)
1168 _exit(0);
1169
1170 sigemptyset(&mask);
1171 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1172
1173 if (setsid() < 0)
1174 emergency("setsid failed (window) %m");
1175
1176 #ifdef LOGIN_CAP
1177 setprocresources(RESOURCE_WINDOW);
1178 #endif
1179 if (sp->se_type) {
1180 /* Don't use malloc after fork */
1181 strcpy(term, "TERM=");
1182 strncat(term, sp->se_type, sizeof(term) - 6);
1183 env[0] = term;
1184 env[1] = 0;
1185 }
1186 else
1187 env[0] = 0;
1188 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1189 stall("can't exec window system '%s' for port %s: %m",
1190 sp->se_window_argv[0], sp->se_device);
1191 _exit(1);
1192 }
1193
1194 /*
1195 * Start a login session running.
1196 */
1197 static pid_t
start_getty(session_t * sp)1198 start_getty(session_t *sp)
1199 {
1200 pid_t pid;
1201 sigset_t mask;
1202 time_t current_time = time((time_t *) 0);
1203 int too_quick = 0;
1204 char term[64], *env[2];
1205
1206 if (current_time >= sp->se_started &&
1207 current_time - sp->se_started < GETTY_SPACING) {
1208 if (++sp->se_nspace > GETTY_NSPACE) {
1209 sp->se_nspace = 0;
1210 too_quick = 1;
1211 }
1212 } else
1213 sp->se_nspace = 0;
1214
1215 /*
1216 * fork(), not vfork() -- we can't afford to block.
1217 */
1218 if ((pid = fork()) == -1) {
1219 emergency("can't fork for getty on port %s: %m", sp->se_device);
1220 return -1;
1221 }
1222
1223 if (pid)
1224 return pid;
1225
1226 if (too_quick) {
1227 warning("getty repeating too quickly on port %s, sleeping %d secs",
1228 sp->se_device, GETTY_SLEEP);
1229 sleep((unsigned) GETTY_SLEEP);
1230 }
1231
1232 if (sp->se_window) {
1233 start_window_system(sp);
1234 sleep(WINDOW_WAIT);
1235 }
1236
1237 sigemptyset(&mask);
1238 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1239
1240 #ifdef LOGIN_CAP
1241 setprocresources(RESOURCE_GETTY);
1242 #endif
1243 if (sp->se_type) {
1244 /* Don't use malloc after fork */
1245 strcpy(term, "TERM=");
1246 strncat(term, sp->se_type, sizeof(term) - 6);
1247 env[0] = term;
1248 env[1] = 0;
1249 } else
1250 env[0] = 0;
1251 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1252 stall("can't exec getty '%s' for port %s: %m",
1253 sp->se_getty_argv[0], sp->se_device);
1254 _exit(1);
1255 }
1256
1257 /*
1258 * Collect exit status for a child.
1259 * If an exiting login, start a new login running.
1260 */
1261 static void
collect_child(pid_t pid)1262 collect_child(pid_t pid)
1263 {
1264 session_t *sp, *sprev, *snext;
1265
1266 if (! sessions)
1267 return;
1268
1269 if (! (sp = find_session(pid)))
1270 return;
1271
1272 del_session(sp);
1273 sp->se_process = 0;
1274
1275 if (sp->se_flags & SE_SHUTDOWN) {
1276 if ((sprev = sp->se_prev) != NULL)
1277 sprev->se_next = sp->se_next;
1278 else
1279 sessions = sp->se_next;
1280 if ((snext = sp->se_next) != NULL)
1281 snext->se_prev = sp->se_prev;
1282 free_session(sp);
1283 return;
1284 }
1285
1286 if ((pid = start_getty(sp)) == -1) {
1287 /* serious trouble */
1288 requested_transition = clean_ttys;
1289 return;
1290 }
1291
1292 sp->se_process = pid;
1293 sp->se_started = time((time_t *) 0);
1294 add_session(sp);
1295 }
1296
1297 /*
1298 * Catch a signal and request a state transition.
1299 */
1300 static void
transition_handler(int sig)1301 transition_handler(int sig)
1302 {
1303
1304 switch (sig) {
1305 case SIGHUP:
1306 if (current_state == read_ttys || current_state == multi_user ||
1307 current_state == clean_ttys || current_state == catatonia)
1308 requested_transition = clean_ttys;
1309 break;
1310 case SIGUSR2:
1311 howto = RB_POWEROFF;
1312 case SIGUSR1:
1313 howto |= RB_HALT;
1314 case SIGINT:
1315 Reboot = TRUE;
1316 case SIGTERM:
1317 if (current_state == read_ttys || current_state == multi_user ||
1318 current_state == clean_ttys || current_state == catatonia)
1319 requested_transition = death;
1320 else
1321 requested_transition = death_single;
1322 break;
1323 case SIGTSTP:
1324 if (current_state == runcom || current_state == read_ttys ||
1325 current_state == clean_ttys ||
1326 current_state == multi_user || current_state == catatonia)
1327 requested_transition = catatonia;
1328 break;
1329 default:
1330 requested_transition = 0;
1331 break;
1332 }
1333 }
1334
1335 /*
1336 * Take the system multiuser.
1337 */
1338 static state_func_t
multi_user(void)1339 multi_user(void)
1340 {
1341 pid_t pid;
1342 session_t *sp;
1343
1344 requested_transition = 0;
1345
1346 /*
1347 * If the administrator has not set the security level to -1
1348 * to indicate that the kernel should not run multiuser in secure
1349 * mode, and the run script has not set a higher level of security
1350 * than level 1, then put the kernel into secure mode.
1351 */
1352 if (getsecuritylevel() == 0)
1353 setsecuritylevel(1);
1354
1355 for (sp = sessions; sp; sp = sp->se_next) {
1356 if (sp->se_process)
1357 continue;
1358 if ((pid = start_getty(sp)) == -1) {
1359 /* serious trouble */
1360 requested_transition = clean_ttys;
1361 break;
1362 }
1363 sp->se_process = pid;
1364 sp->se_started = time((time_t *) 0);
1365 add_session(sp);
1366 }
1367
1368 while (!requested_transition)
1369 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1370 collect_child(pid);
1371
1372 return (state_func_t) requested_transition;
1373 }
1374
1375 /*
1376 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1377 */
1378 static state_func_t
clean_ttys(void)1379 clean_ttys(void)
1380 {
1381 session_t *sp, *sprev;
1382 struct ttyent *typ;
1383 int session_index = 0;
1384 int devlen;
1385 char *old_getty, *old_window, *old_type;
1386
1387 /*
1388 * mark all sessions for death, (!SE_PRESENT)
1389 * as we find or create new ones they'll be marked as keepers,
1390 * we'll later nuke all the ones not found in /etc/ttys
1391 */
1392 for (sp = sessions; sp != NULL; sp = sp->se_next)
1393 sp->se_flags &= ~SE_PRESENT;
1394
1395 devlen = sizeof(_PATH_DEV) - 1;
1396 while ((typ = getttyent()) != NULL) {
1397 ++session_index;
1398
1399 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1400 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1401 break;
1402
1403 if (sp) {
1404 /* we want this one to live */
1405 sp->se_flags |= SE_PRESENT;
1406 if (sp->se_index != session_index) {
1407 warning("port %s changed utmp index from %d to %d",
1408 sp->se_device, sp->se_index,
1409 session_index);
1410 sp->se_index = session_index;
1411 }
1412 if ((typ->ty_status & TTY_ON) == 0 ||
1413 typ->ty_getty == 0) {
1414 sp->se_flags |= SE_SHUTDOWN;
1415 kill(sp->se_process, SIGHUP);
1416 continue;
1417 }
1418 sp->se_flags &= ~SE_SHUTDOWN;
1419 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1420 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1421 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1422 if (setupargv(sp, typ) == 0) {
1423 warning("can't parse getty for port %s",
1424 sp->se_device);
1425 sp->se_flags |= SE_SHUTDOWN;
1426 kill(sp->se_process, SIGHUP);
1427 }
1428 else if ( !old_getty
1429 || (!old_type && sp->se_type)
1430 || (old_type && !sp->se_type)
1431 || (!old_window && sp->se_window)
1432 || (old_window && !sp->se_window)
1433 || (strcmp(old_getty, sp->se_getty) != 0)
1434 || (old_window && strcmp(old_window, sp->se_window) != 0)
1435 || (old_type && strcmp(old_type, sp->se_type) != 0)
1436 ) {
1437 /* Don't set SE_SHUTDOWN here */
1438 sp->se_nspace = 0;
1439 sp->se_started = 0;
1440 kill(sp->se_process, SIGHUP);
1441 }
1442 if (old_getty)
1443 free(old_getty);
1444 if (old_window)
1445 free(old_window);
1446 if (old_type)
1447 free(old_type);
1448 continue;
1449 }
1450
1451 new_session(sprev, session_index, typ);
1452 }
1453
1454 endttyent();
1455
1456 /*
1457 * sweep through and kill all deleted sessions
1458 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1459 */
1460 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1461 if ((sp->se_flags & SE_PRESENT) == 0) {
1462 sp->se_flags |= SE_SHUTDOWN;
1463 kill(sp->se_process, SIGHUP);
1464 }
1465 }
1466
1467 return (state_func_t) multi_user;
1468 }
1469
1470 /*
1471 * Block further logins.
1472 */
1473 static state_func_t
catatonia(void)1474 catatonia(void)
1475 {
1476 session_t *sp;
1477
1478 for (sp = sessions; sp; sp = sp->se_next)
1479 sp->se_flags |= SE_SHUTDOWN;
1480
1481 return (state_func_t) multi_user;
1482 }
1483
1484 /*
1485 * Note SIGALRM.
1486 */
1487 static void
alrm_handler(int sig)1488 alrm_handler(int sig)
1489 {
1490
1491 (void)sig;
1492 clang = 1;
1493 }
1494
1495 /*
1496 * Bring the system down to single user.
1497 */
1498 static state_func_t
death(void)1499 death(void)
1500 {
1501 session_t *sp;
1502
1503 /*
1504 * Also revoke the TTY here. Because runshutdown() may reopen
1505 * the TTY whose getty we're killing here, there is no guarantee
1506 * runshutdown() will perform the initial open() call, causing
1507 * the terminal attributes to be misconfigured.
1508 */
1509 for (sp = sessions; sp; sp = sp->se_next) {
1510 sp->se_flags |= SE_SHUTDOWN;
1511 kill(sp->se_process, SIGHUP);
1512 revoke(sp->se_device);
1513 }
1514
1515 /* Try to run the rc.shutdown script within a period of time */
1516 runshutdown();
1517
1518 return (state_func_t) death_single;
1519 }
1520
1521 /*
1522 * Do what is necessary to reinitialize single user mode or reboot
1523 * from an incomplete state.
1524 */
1525 static state_func_t
death_single(void)1526 death_single(void)
1527 {
1528 int i;
1529 pid_t pid;
1530 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1531
1532 revoke(_PATH_CONSOLE);
1533
1534 for (i = 0; i < 2; ++i) {
1535 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1536 return (state_func_t) single_user;
1537
1538 clang = 0;
1539 alarm(DEATH_WATCH);
1540 do
1541 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1542 collect_child(pid);
1543 while (clang == 0 && errno != ECHILD);
1544
1545 if (errno == ECHILD)
1546 return (state_func_t) single_user;
1547 }
1548
1549 warning("some processes would not die; ps axl advised");
1550
1551 return (state_func_t) single_user;
1552 }
1553
1554 /*
1555 * Run the system shutdown script.
1556 *
1557 * Exit codes: XXX I should document more
1558 * -2 shutdown script terminated abnormally
1559 * -1 fatal error - can't run script
1560 * 0 good.
1561 * >0 some error (exit code)
1562 */
1563 static int
runshutdown(void)1564 runshutdown(void)
1565 {
1566 pid_t pid, wpid;
1567 int status;
1568 int shutdowntimeout;
1569 size_t len;
1570 char *argv[4];
1571 const char *shell;
1572 struct sigaction sa;
1573 struct stat sb;
1574
1575 /*
1576 * rc.shutdown is optional, so to prevent any unnecessary
1577 * complaints from the shell we simply don't run it if the
1578 * file does not exist. If the stat() here fails for other
1579 * reasons, we'll let the shell complain.
1580 */
1581 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1582 return 0;
1583
1584 shell = get_shell();
1585
1586 if ((pid = fork()) == 0) {
1587 sigemptyset(&sa.sa_mask);
1588 sa.sa_flags = 0;
1589 sa.sa_handler = SIG_IGN;
1590 sigaction(SIGTSTP, &sa, (struct sigaction *)0);
1591 sigaction(SIGHUP, &sa, (struct sigaction *)0);
1592
1593 open_console();
1594
1595 char _sh[] = "sh";
1596 char _reboot[] = "reboot";
1597 char _single[] = "single";
1598 char _path_rundown[] = _PATH_RUNDOWN;
1599
1600 argv[0] = _sh;
1601 argv[1] = _path_rundown;
1602 argv[2] = Reboot ? _reboot : _single;
1603 argv[3] = 0;
1604
1605 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
1606
1607 #ifdef LOGIN_CAP
1608 setprocresources(RESOURCE_RC);
1609 #endif
1610 execv(shell, argv);
1611 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN);
1612 _exit(1); /* force single user mode */
1613 }
1614
1615 if (pid == -1) {
1616 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN);
1617 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1618 continue;
1619 sleep(STALL_TIMEOUT);
1620 return -1;
1621 }
1622
1623 len = sizeof(shutdowntimeout);
1624 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
1625 NULL, 0) == -1 || shutdowntimeout < 2)
1626 shutdowntimeout = DEATH_SCRIPT;
1627 alarm(shutdowntimeout);
1628 clang = 0;
1629 /*
1630 * Copied from single_user(). This is a bit paranoid.
1631 * Use the same ALRM handler.
1632 */
1633 do {
1634 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1635 collect_child(wpid);
1636 if (clang == 1) {
1637 /* we were waiting for the sub-shell */
1638 kill(wpid, SIGTERM);
1639 warning("timeout expired for %s on %s: %m; going to "
1640 "single user mode", shell, _PATH_RUNDOWN);
1641 return -1;
1642 }
1643 if (wpid == -1) {
1644 if (errno == EINTR)
1645 continue;
1646 warning("wait for %s on %s failed: %m; going to "
1647 "single user mode", shell, _PATH_RUNDOWN);
1648 return -1;
1649 }
1650 if (wpid == pid && WIFSTOPPED(status)) {
1651 warning("init: %s on %s stopped, restarting\n",
1652 shell, _PATH_RUNDOWN);
1653 kill(pid, SIGCONT);
1654 wpid = -1;
1655 }
1656 } while (wpid != pid && !clang);
1657
1658 /* Turn off the alarm */
1659 alarm(0);
1660
1661 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1662 requested_transition == catatonia) {
1663 /*
1664 * /etc/rc.shutdown executed /sbin/reboot;
1665 * wait for the end quietly
1666 */
1667 sigset_t s;
1668
1669 sigfillset(&s);
1670 for (;;)
1671 sigsuspend(&s);
1672 }
1673
1674 if (!WIFEXITED(status)) {
1675 warning("%s on %s terminated abnormally, going to "
1676 "single user mode", shell, _PATH_RUNDOWN);
1677 return -2;
1678 }
1679
1680 if ((status = WEXITSTATUS(status)) != 0)
1681 warning("%s returned status %d", _PATH_RUNDOWN, status);
1682
1683 return status;
1684 }
1685
1686 static char *
strk(char * p)1687 strk(char *p)
1688 {
1689 static char *t;
1690 char *q;
1691 int c;
1692
1693 if (p)
1694 t = p;
1695 if (!t)
1696 return 0;
1697
1698 c = *t;
1699 while (c == ' ' || c == '\t' )
1700 c = *++t;
1701 if (!c) {
1702 t = 0;
1703 return 0;
1704 }
1705 q = t;
1706 if (c == '\'') {
1707 c = *++t;
1708 q = t;
1709 while (c && c != '\'')
1710 c = *++t;
1711 if (!c) /* unterminated string */
1712 q = t = 0;
1713 else
1714 *t++ = 0;
1715 } else {
1716 while (c && c != ' ' && c != '\t' )
1717 c = *++t;
1718 *t++ = 0;
1719 if (!c)
1720 t = 0;
1721 }
1722 return q;
1723 }
1724
1725 #ifdef LOGIN_CAP
1726 static void
setprocresources(const char * cname)1727 setprocresources(const char *cname)
1728 {
1729 login_cap_t *lc;
1730 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1731 setusercontext(lc, (struct passwd*)NULL, 0,
1732 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
1733 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
1734 login_close(lc);
1735 }
1736 }
1737 #endif
1738