1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Donn Seeley at Berkeley Software Design, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/param.h>
36 #include <sys/boottrace.h>
37 #include <sys/ioctl.h>
38 #include <sys/mman.h>
39 #include <sys/mount.h>
40 #include <sys/reboot.h>
41 #include <sys/stat.h>
42 #include <sys/sysctl.h>
43 #include <sys/uio.h>
44 #include <sys/wait.h>
45
46 #include <db.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <kenv.h>
51 #include <libutil.h>
52 #include <mntopts.h>
53 #include <paths.h>
54 #include <signal.h>
55 #include <stdarg.h>
56 #include <stdbool.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <syslog.h>
61 #include <time.h>
62 #include <ttyent.h>
63 #include <unistd.h>
64
65 #ifdef SECURE
66 #include <pwd.h>
67 #endif
68
69 #ifdef LOGIN_CAP
70 #include <login_cap.h>
71 #endif
72
73 #include "pathnames.h"
74
75 /*
76 * Sleep times; used to prevent thrashing.
77 */
78 #define GETTY_SPACING 5 /* N secs minimum getty spacing */
79 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */
80 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */
81 #define WINDOW_WAIT 3 /* wait N secs after starting window */
82 #define STALL_TIMEOUT 30 /* wait N secs after warning */
83 #define DEATH_WATCH 10 /* wait N secs for procs to die */
84 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */
85 #define RESOURCE_RC "daemon"
86 #define RESOURCE_WINDOW "default"
87 #define RESOURCE_GETTY "default"
88 #define SCRIPT_ARGV_SIZE 3 /* size of argv passed to execute_script, can be increased if needed */
89
90 static void handle(sig_t, ...);
91 static void delset(sigset_t *, ...);
92
93 static void stall(const char *, ...) __printflike(1, 2);
94 static void warning(const char *, ...) __printflike(1, 2);
95 static void emergency(const char *, ...) __printflike(1, 2);
96 static void disaster(int);
97 static void revoke_ttys(void);
98 static int runshutdown(void);
99 static char *strk(char *);
100 static void runfinal(void);
101
102 /*
103 * We really need a recursive typedef...
104 * The following at least guarantees that the return type of (*state_t)()
105 * is sufficiently wide to hold a function pointer.
106 */
107 typedef long (*state_func_t)(void);
108 typedef state_func_t (*state_t)(void);
109
110 static state_func_t single_user(void);
111 static state_func_t runcom(void);
112 static state_func_t read_ttys(void);
113 static state_func_t multi_user(void);
114 static state_func_t clean_ttys(void);
115 static state_func_t catatonia(void);
116 static state_func_t death(void);
117 static state_func_t death_single(void);
118 static state_func_t reroot(void);
119 static state_func_t reroot_phase_two(void);
120
121 static state_func_t run_script(const char *);
122
123 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
124
125 static bool Reboot = false;
126 static int howto = RB_AUTOBOOT;
127
128 static bool devfs = false;
129 static char *init_path_argv0;
130
131 static void transition(state_t);
132 static state_t requested_transition;
133 static state_t current_state = death_single;
134
135 static void execute_script(char *argv[]);
136 static void open_console(void);
137 static const char *get_shell(void);
138 static void replace_init(char *path);
139 static void write_stderr(const char *message);
140
141 typedef struct init_session {
142 pid_t se_process; /* controlling process */
143 time_t se_started; /* used to avoid thrashing */
144 int se_flags; /* status of session */
145 #define SE_SHUTDOWN 0x1 /* session won't be restarted */
146 #define SE_PRESENT 0x2 /* session is in /etc/ttys */
147 #define SE_IFEXISTS 0x4 /* session defined as "onifexists" */
148 #define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */
149 int se_nspace; /* spacing count */
150 char *se_device; /* filename of port */
151 char *se_getty; /* what to run on that port */
152 char *se_getty_argv_space; /* pre-parsed argument array space */
153 char **se_getty_argv; /* pre-parsed argument array */
154 char *se_window; /* window system (started only once) */
155 char *se_window_argv_space; /* pre-parsed argument array space */
156 char **se_window_argv; /* pre-parsed argument array */
157 char *se_type; /* default terminal type */
158 struct init_session *se_prev;
159 struct init_session *se_next;
160 } session_t;
161
162 static void free_session(session_t *);
163 static session_t *new_session(session_t *, struct ttyent *);
164 static session_t *sessions;
165
166 static char **construct_argv(char *);
167 static void start_window_system(session_t *);
168 static void collect_child(pid_t);
169 static pid_t start_getty(session_t *);
170 static void transition_handler(int);
171 static void alrm_handler(int);
172 static void setsecuritylevel(int);
173 static int getsecuritylevel(void);
174 static int setupargv(session_t *, struct ttyent *);
175 #ifdef LOGIN_CAP
176 static void setprocresources(const char *);
177 #endif
178 static bool clang;
179
180 static int start_session_db(void);
181 static void add_session(session_t *);
182 static void del_session(session_t *);
183 static session_t *find_session(pid_t);
184 static DB *session_db;
185
186 /*
187 * The mother of all processes.
188 */
189 int
main(int argc,char * argv[])190 main(int argc, char *argv[])
191 {
192 state_t initial_transition = runcom;
193 char kenv_value[PATH_MAX];
194 int c, error;
195 struct sigaction sa;
196 sigset_t mask;
197
198 /* Dispose of random users. */
199 if (getuid() != 0)
200 errx(1, "%s", strerror(EPERM));
201
202 BOOTTRACE("init(8) starting...");
203
204 /* System V users like to reexec init. */
205 if (getpid() != 1) {
206 #ifdef COMPAT_SYSV_INIT
207 /* So give them what they want */
208 if (argc > 1) {
209 if (strlen(argv[1]) == 1) {
210 char runlevel = *argv[1];
211 int sig;
212
213 switch (runlevel) {
214 case '0': /* halt + poweroff */
215 sig = SIGUSR2;
216 break;
217 case '1': /* single-user */
218 sig = SIGTERM;
219 break;
220 case '6': /* reboot */
221 sig = SIGINT;
222 break;
223 case 'c': /* block further logins */
224 sig = SIGTSTP;
225 break;
226 case 'q': /* rescan /etc/ttys */
227 sig = SIGHUP;
228 break;
229 case 'r': /* remount root */
230 sig = SIGEMT;
231 break;
232 default:
233 goto invalid;
234 }
235 kill(1, sig);
236 _exit(0);
237 } else
238 invalid:
239 errx(1, "invalid run-level ``%s''", argv[1]);
240 } else
241 #endif
242 errx(1, "already running");
243 }
244
245 init_path_argv0 = strdup(argv[0]);
246 if (init_path_argv0 == NULL)
247 err(1, "strdup");
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 = true;
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(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
299 SIGXCPU, SIGXFSZ, 0);
300 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
301 SIGUSR1, SIGUSR2, SIGWINCH, 0);
302 handle(alrm_handler, SIGALRM, 0);
303 sigfillset(&mask);
304 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
305 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
306 SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0);
307 sigprocmask(SIG_SETMASK, &mask, NULL);
308 sigemptyset(&sa.sa_mask);
309 sa.sa_flags = 0;
310 sa.sa_handler = SIG_IGN;
311 sigaction(SIGTTIN, &sa, NULL);
312 sigaction(SIGTTOU, &sa, NULL);
313
314 /*
315 * Paranoia.
316 */
317 close(0);
318 close(1);
319 close(2);
320
321 if (kenv(KENV_GET, "init_exec", kenv_value, sizeof(kenv_value)) > 0) {
322 replace_init(kenv_value);
323 _exit(0); /* reboot */
324 }
325
326 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
327 state_func_t next_transition;
328
329 if ((next_transition = run_script(kenv_value)) != NULL)
330 initial_transition = (state_t) next_transition;
331 }
332
333 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
334 if (chdir(kenv_value) != 0 || chroot(".") != 0)
335 warning("Can't chroot to %s: %m", kenv_value);
336 }
337
338 /*
339 * Additional check if devfs needs to be mounted:
340 * If "/" and "/dev" have the same device number,
341 * then it hasn't been mounted yet.
342 */
343 if (!devfs) {
344 struct stat stst;
345 dev_t root_devno;
346
347 stat("/", &stst);
348 root_devno = stst.st_dev;
349 if (stat("/dev", &stst) != 0)
350 warning("Can't stat /dev: %m");
351 else if (stst.st_dev == root_devno)
352 devfs = true;
353 }
354
355 if (devfs) {
356 struct iovec iov[4];
357 char *s;
358 int i;
359
360 char _fstype[] = "fstype";
361 char _devfs[] = "devfs";
362 char _fspath[] = "fspath";
363 char _path_dev[]= _PATH_DEV;
364
365 iov[0].iov_base = _fstype;
366 iov[0].iov_len = sizeof(_fstype);
367 iov[1].iov_base = _devfs;
368 iov[1].iov_len = sizeof(_devfs);
369 iov[2].iov_base = _fspath;
370 iov[2].iov_len = sizeof(_fspath);
371 /*
372 * Try to avoid the trailing slash in _PATH_DEV.
373 * Be *very* defensive.
374 */
375 s = strdup(_PATH_DEV);
376 if (s != NULL) {
377 i = strlen(s);
378 if (i > 0 && s[i - 1] == '/')
379 s[i - 1] = '\0';
380 iov[3].iov_base = s;
381 iov[3].iov_len = strlen(s) + 1;
382 } else {
383 iov[3].iov_base = _path_dev;
384 iov[3].iov_len = sizeof(_path_dev);
385 }
386 nmount(iov, 4, 0);
387 if (s != NULL)
388 free(s);
389 }
390
391 if (initial_transition != reroot_phase_two) {
392 /*
393 * Unmount reroot leftovers. This runs after init(8)
394 * gets reexecuted after reroot_phase_two() is done.
395 */
396 error = unmount(_PATH_REROOT, MNT_FORCE);
397 if (error != 0 && errno != EINVAL)
398 warning("Cannot unmount %s: %m", _PATH_REROOT);
399 }
400
401 /*
402 * Start the state machine.
403 */
404 transition(initial_transition);
405
406 /*
407 * Should never reach here.
408 */
409 return 1;
410 }
411
412 /*
413 * Associate a function with a signal handler.
414 */
415 static void
handle(sig_t handler,...)416 handle(sig_t handler, ...)
417 {
418 int sig;
419 struct sigaction sa;
420 sigset_t mask_everything;
421 va_list ap;
422 va_start(ap, handler);
423
424 sa.sa_handler = handler;
425 sigfillset(&mask_everything);
426
427 while ((sig = va_arg(ap, int)) != 0) {
428 sa.sa_mask = mask_everything;
429 /* XXX SA_RESTART? */
430 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
431 sigaction(sig, &sa, NULL);
432 }
433 va_end(ap);
434 }
435
436 /*
437 * Delete a set of signals from a mask.
438 */
439 static void
delset(sigset_t * maskp,...)440 delset(sigset_t *maskp, ...)
441 {
442 int sig;
443 va_list ap;
444 va_start(ap, maskp);
445
446 while ((sig = va_arg(ap, int)) != 0)
447 sigdelset(maskp, sig);
448 va_end(ap);
449 }
450
451 /*
452 * Log a message and sleep for a while (to give someone an opportunity
453 * to read it and to save log or hardcopy output if the problem is chronic).
454 * NB: should send a message to the session logger to avoid blocking.
455 */
456 static void
stall(const char * message,...)457 stall(const char *message, ...)
458 {
459 va_list ap;
460 va_start(ap, message);
461
462 vsyslog(LOG_ALERT, message, ap);
463 va_end(ap);
464 sleep(STALL_TIMEOUT);
465 }
466
467 /*
468 * Like stall(), but doesn't sleep.
469 * If cpp had variadic macros, the two functions could be #defines for another.
470 * NB: should send a message to the session logger to avoid blocking.
471 */
472 static void
warning(const char * message,...)473 warning(const char *message, ...)
474 {
475 va_list ap;
476 va_start(ap, message);
477
478 vsyslog(LOG_ALERT, message, ap);
479 va_end(ap);
480 }
481
482 /*
483 * Log an emergency message.
484 * NB: should send a message to the session logger to avoid blocking.
485 */
486 static void
emergency(const char * message,...)487 emergency(const char *message, ...)
488 {
489 va_list ap;
490 va_start(ap, message);
491
492 vsyslog(LOG_EMERG, message, ap);
493 va_end(ap);
494 }
495
496 /*
497 * Catch an unexpected signal.
498 */
499 static void
disaster(int sig)500 disaster(int sig)
501 {
502
503 emergency("fatal signal: %s",
504 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
505
506 sleep(STALL_TIMEOUT);
507 _exit(sig); /* reboot */
508 }
509
510 /*
511 * Get the security level of the kernel.
512 */
513 static int
getsecuritylevel(void)514 getsecuritylevel(void)
515 {
516 #ifdef KERN_SECURELVL
517 int name[2], curlevel;
518 size_t len;
519
520 name[0] = CTL_KERN;
521 name[1] = KERN_SECURELVL;
522 len = sizeof curlevel;
523 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
524 emergency("cannot get kernel security level: %m");
525 return (-1);
526 }
527 return (curlevel);
528 #else
529 return (-1);
530 #endif
531 }
532
533 /*
534 * Set the security level of the kernel.
535 */
536 static void
setsecuritylevel(int newlevel)537 setsecuritylevel(int newlevel)
538 {
539 #ifdef KERN_SECURELVL
540 int name[2], curlevel;
541
542 curlevel = getsecuritylevel();
543 if (newlevel == curlevel)
544 return;
545 name[0] = CTL_KERN;
546 name[1] = KERN_SECURELVL;
547 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
548 emergency(
549 "cannot change kernel security level from %d to %d: %m",
550 curlevel, newlevel);
551 return;
552 }
553 #ifdef SECURE
554 warning("kernel security level changed from %d to %d",
555 curlevel, newlevel);
556 #endif
557 #endif
558 }
559
560 /*
561 * Change states in the finite state machine.
562 * The initial state is passed as an argument.
563 */
564 static void
transition(state_t s)565 transition(state_t s)
566 {
567
568 current_state = s;
569 for (;;)
570 current_state = (state_t) (*current_state)();
571 }
572
573 /*
574 * Start a session and allocate a controlling terminal.
575 * Only called by children of init after forking.
576 */
577 static void
open_console(void)578 open_console(void)
579 {
580 int fd;
581
582 /*
583 * Try to open /dev/console. Open the device with O_NONBLOCK to
584 * prevent potential blocking on a carrier.
585 */
586 revoke(_PATH_CONSOLE);
587 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) {
588 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
589 if (login_tty(fd) == 0)
590 return;
591 close(fd);
592 }
593
594 /* No luck. Log output to file if possible. */
595 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
596 stall("cannot open null device.");
597 _exit(1);
598 }
599 if (fd != STDIN_FILENO) {
600 dup2(fd, STDIN_FILENO);
601 close(fd);
602 }
603 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644);
604 if (fd == -1)
605 dup2(STDIN_FILENO, STDOUT_FILENO);
606 else if (fd != STDOUT_FILENO) {
607 dup2(fd, STDOUT_FILENO);
608 close(fd);
609 }
610 dup2(STDOUT_FILENO, STDERR_FILENO);
611 }
612
613 static const char *
get_shell(void)614 get_shell(void)
615 {
616 static char kenv_value[PATH_MAX];
617
618 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
619 return kenv_value;
620 else
621 return _PATH_BSHELL;
622 }
623
624 static void
write_stderr(const char * message)625 write_stderr(const char *message)
626 {
627
628 write(STDERR_FILENO, message, strlen(message));
629 }
630
631 static int
read_file(const char * path,void ** bufp,size_t * bufsizep)632 read_file(const char *path, void **bufp, size_t *bufsizep)
633 {
634 struct stat sb;
635 size_t bufsize;
636 void *buf;
637 ssize_t nbytes;
638 int error, fd;
639
640 fd = open(path, O_RDONLY);
641 if (fd < 0) {
642 emergency("%s: %m", path);
643 return (-1);
644 }
645
646 error = fstat(fd, &sb);
647 if (error != 0) {
648 emergency("fstat: %m");
649 close(fd);
650 return (error);
651 }
652
653 bufsize = sb.st_size;
654 buf = malloc(bufsize);
655 if (buf == NULL) {
656 emergency("malloc: %m");
657 close(fd);
658 return (error);
659 }
660
661 nbytes = read(fd, buf, bufsize);
662 if (nbytes != (ssize_t)bufsize) {
663 emergency("read: %m");
664 close(fd);
665 free(buf);
666 return (error);
667 }
668
669 error = close(fd);
670 if (error != 0) {
671 emergency("close: %m");
672 free(buf);
673 return (error);
674 }
675
676 *bufp = buf;
677 *bufsizep = bufsize;
678
679 return (0);
680 }
681
682 static int
create_file(const char * path,const void * buf,size_t bufsize)683 create_file(const char *path, const void *buf, size_t bufsize)
684 {
685 ssize_t nbytes;
686 int error, fd;
687
688 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700);
689 if (fd < 0) {
690 emergency("%s: %m", path);
691 return (-1);
692 }
693
694 nbytes = write(fd, buf, bufsize);
695 if (nbytes != (ssize_t)bufsize) {
696 emergency("write: %m");
697 close(fd);
698 return (-1);
699 }
700
701 error = close(fd);
702 if (error != 0) {
703 emergency("close: %m");
704 return (-1);
705 }
706
707 return (0);
708 }
709
710 static int
mount_tmpfs(const char * fspath)711 mount_tmpfs(const char *fspath)
712 {
713 struct iovec *iov;
714 char errmsg[255];
715 int error, iovlen;
716
717 iov = NULL;
718 iovlen = 0;
719 memset(errmsg, 0, sizeof(errmsg));
720 build_iovec(&iov, &iovlen, "fstype",
721 __DECONST(void *, "tmpfs"), (size_t)-1);
722 build_iovec(&iov, &iovlen, "fspath",
723 __DECONST(void *, fspath), (size_t)-1);
724 build_iovec(&iov, &iovlen, "errmsg",
725 errmsg, sizeof(errmsg));
726
727 error = nmount(iov, iovlen, 0);
728 if (error != 0) {
729 if (*errmsg != '\0') {
730 emergency("cannot mount tmpfs on %s: %s: %m",
731 fspath, errmsg);
732 } else {
733 emergency("cannot mount tmpfs on %s: %m",
734 fspath);
735 }
736 return (error);
737 }
738 return (0);
739 }
740
741 static state_func_t
reroot(void)742 reroot(void)
743 {
744 void *buf;
745 size_t bufsize;
746 int error;
747
748 buf = NULL;
749 bufsize = 0;
750
751 revoke_ttys();
752 runshutdown();
753
754 /*
755 * Make sure nobody can interfere with our scheme.
756 * Ignore ESRCH, which can apparently happen when
757 * there are no processes to kill.
758 */
759 error = kill(-1, SIGKILL);
760 if (error != 0 && errno != ESRCH) {
761 emergency("kill(2) failed: %m");
762 goto out;
763 }
764
765 /*
766 * Copy the init binary into tmpfs, so that we can unmount
767 * the old rootfs without committing suicide.
768 */
769 error = read_file(init_path_argv0, &buf, &bufsize);
770 if (error != 0)
771 goto out;
772 error = mount_tmpfs(_PATH_REROOT);
773 if (error != 0)
774 goto out;
775 error = create_file(_PATH_REROOT_INIT, buf, bufsize);
776 if (error != 0)
777 goto out;
778
779 /*
780 * Execute the temporary init.
781 */
782 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL);
783 emergency("cannot exec %s: %m", _PATH_REROOT_INIT);
784
785 out:
786 emergency("reroot failed; going to single user mode");
787 free(buf);
788 return (state_func_t) single_user;
789 }
790
791 static state_func_t
reroot_phase_two(void)792 reroot_phase_two(void)
793 {
794 char init_path[PATH_MAX], *path, *path_component;
795 size_t init_path_len;
796 int nbytes, error;
797
798 /*
799 * Ask the kernel to mount the new rootfs.
800 */
801 error = reboot(RB_REROOT);
802 if (error != 0) {
803 emergency("RB_REBOOT failed: %m");
804 goto out;
805 }
806
807 /*
808 * Figure out where the destination init(8) binary is. Note that
809 * the path could be different than what we've started with. Use
810 * the value from kenv, if set, or the one from sysctl otherwise.
811 * The latter defaults to a hardcoded value, but can be overridden
812 * by a build time option.
813 */
814 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path));
815 if (nbytes <= 0) {
816 init_path_len = sizeof(init_path);
817 error = sysctlbyname("kern.init_path",
818 init_path, &init_path_len, NULL, 0);
819 if (error != 0) {
820 emergency("failed to retrieve kern.init_path: %m");
821 goto out;
822 }
823 }
824
825 /*
826 * Repeat the init search logic from sys/kern/init_path.c
827 */
828 path_component = init_path;
829 while ((path = strsep(&path_component, ":")) != NULL) {
830 /*
831 * Execute init(8) from the new rootfs.
832 */
833 execl(path, path, NULL);
834 }
835 emergency("cannot exec init from %s: %m", init_path);
836
837 out:
838 emergency("reroot failed; going to single user mode");
839 return (state_func_t) single_user;
840 }
841
842 /*
843 * Bring the system up single user.
844 */
845 static state_func_t
single_user(void)846 single_user(void)
847 {
848 pid_t pid, wpid;
849 int status;
850 sigset_t mask;
851 const char *shell;
852 char *argv[2];
853 struct timeval tv, tn;
854 struct passwd *pp;
855 #ifdef SECURE
856 struct ttyent *typ;
857 static const char banner[] =
858 "Enter root password, or ^D to go multi-user\n";
859 char *clear, *password;
860 #endif
861 #ifdef DEBUGSHELL
862 char altshell[128];
863 #endif
864
865 if (Reboot) {
866 /* Instead of going single user, let's reboot the machine */
867 BOOTTRACE("shutting down the system");
868 sync();
869 /* Run scripts after all processes have been terminated. */
870 runfinal();
871 if (reboot(howto) == -1) {
872 emergency("reboot(%#x) failed, %m", howto);
873 _exit(1); /* panic and reboot */
874 }
875 warning("reboot(%#x) returned", howto);
876 _exit(0); /* panic as well */
877 }
878
879 BOOTTRACE("going to single user mode");
880 shell = get_shell();
881
882 if ((pid = fork()) == 0) {
883 /*
884 * Start the single user session.
885 */
886 open_console();
887
888 pp = getpwnam("root");
889 #ifdef SECURE
890 /*
891 * Check the root password.
892 * We don't care if the console is 'on' by default;
893 * it's the only tty that can be 'off' and 'secure'.
894 */
895 typ = getttynam("console");
896 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
897 pp && *pp->pw_passwd) {
898 write_stderr(banner);
899 for (;;) {
900 clear = getpass("Password:");
901 if (clear == NULL || *clear == '\0')
902 _exit(0);
903 password = crypt(clear, pp->pw_passwd);
904 explicit_bzero(clear, _PASSWORD_LEN);
905 if (password != NULL &&
906 strcmp(password, pp->pw_passwd) == 0)
907 break;
908 warning("single-user login failed\n");
909 }
910 }
911 endttyent();
912 #endif /* SECURE */
913
914 #ifdef DEBUGSHELL
915 {
916 char *cp = altshell;
917 int num;
918
919 #define SHREQUEST "Enter full pathname of shell or RETURN for "
920 write_stderr(SHREQUEST);
921 write_stderr(shell);
922 write_stderr(": ");
923 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
924 num != 0 && *cp != '\n' && cp < &altshell[127])
925 cp++;
926 *cp = '\0';
927 if (altshell[0] != '\0')
928 shell = altshell;
929 }
930 #endif /* DEBUGSHELL */
931
932 if (pp != NULL && pp->pw_dir != NULL && *pp->pw_dir != '\0' &&
933 chdir(pp->pw_dir) == 0) {
934 setenv("HOME", pp->pw_dir, 1);
935 } else {
936 chdir("/");
937 setenv("HOME", "/", 1);
938 }
939 endpwent();
940
941 /*
942 * Unblock signals.
943 * We catch all the interesting ones,
944 * and those are reset to SIG_DFL on exec.
945 */
946 sigemptyset(&mask);
947 sigprocmask(SIG_SETMASK, &mask, NULL);
948
949 /*
950 * Fire off a shell.
951 * If the default one doesn't work, try the Bourne shell.
952 */
953
954 char name[] = "-sh";
955
956 argv[0] = name;
957 argv[1] = NULL;
958 execv(shell, argv);
959 emergency("can't exec %s for single user: %m", shell);
960 execv(_PATH_BSHELL, argv);
961 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
962 sleep(STALL_TIMEOUT);
963 _exit(1);
964 }
965
966 if (pid == -1) {
967 /*
968 * We are seriously hosed. Do our best.
969 */
970 emergency("can't fork single-user shell, trying again");
971 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
972 continue;
973 return (state_func_t) single_user;
974 }
975
976 requested_transition = 0;
977 do {
978 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
979 collect_child(wpid);
980 if (wpid == -1) {
981 if (errno == EINTR)
982 continue;
983 warning("wait for single-user shell failed: %m; restarting");
984 return (state_func_t) single_user;
985 }
986 if (wpid == pid && WIFSTOPPED(status)) {
987 warning("init: shell stopped, restarting\n");
988 kill(pid, SIGCONT);
989 wpid = -1;
990 }
991 } while (wpid != pid && !requested_transition);
992
993 if (requested_transition)
994 return (state_func_t) requested_transition;
995
996 if (!WIFEXITED(status)) {
997 if (WTERMSIG(status) == SIGKILL) {
998 /*
999 * reboot(8) killed shell?
1000 */
1001 warning("single user shell terminated.");
1002 gettimeofday(&tv, NULL);
1003 tn = tv;
1004 tv.tv_sec += STALL_TIMEOUT;
1005 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec ==
1006 tn.tv_sec && tv.tv_usec > tn.tv_usec)) {
1007 sleep(1);
1008 gettimeofday(&tn, NULL);
1009 }
1010 _exit(0);
1011 } else {
1012 warning("single user shell terminated, restarting");
1013 return (state_func_t) single_user;
1014 }
1015 }
1016
1017 runcom_mode = FASTBOOT;
1018 return (state_func_t) runcom;
1019 }
1020
1021 /*
1022 * Run the system startup script.
1023 */
1024 static state_func_t
runcom(void)1025 runcom(void)
1026 {
1027 state_func_t next_transition;
1028
1029 BOOTTRACE("/etc/rc starting...");
1030 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL)
1031 return next_transition;
1032 BOOTTRACE("/etc/rc finished");
1033
1034 runcom_mode = AUTOBOOT; /* the default */
1035 return (state_func_t) read_ttys;
1036 }
1037
1038 static void
execute_script(char * argv[])1039 execute_script(char *argv[])
1040 {
1041 struct sigaction sa;
1042 char* sh_argv[3 + SCRIPT_ARGV_SIZE];
1043 const char *shell, *script;
1044 int error, sh_argv_len, i;
1045
1046 bzero(&sa, sizeof(sa));
1047 sigemptyset(&sa.sa_mask);
1048 sa.sa_handler = SIG_IGN;
1049 sigaction(SIGTSTP, &sa, NULL);
1050 sigaction(SIGHUP, &sa, NULL);
1051
1052 open_console();
1053
1054 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1055 #ifdef LOGIN_CAP
1056 setprocresources(RESOURCE_RC);
1057 #endif
1058
1059 /*
1060 * Try to directly execute the script first. If it
1061 * fails, try the old method of passing the script path
1062 * to sh(1). Don't complain if it fails because of
1063 * the missing execute bit.
1064 */
1065 script = argv[0];
1066 error = access(script, X_OK);
1067 if (error == 0) {
1068 execv(script, argv);
1069 warning("can't directly exec %s: %m", script);
1070 } else if (errno != EACCES) {
1071 warning("can't access %s: %m", script);
1072 }
1073
1074 shell = get_shell();
1075 sh_argv[0] = __DECONST(char*, shell);
1076 sh_argv_len = 1;
1077 #ifdef SECURE
1078 if (strcmp(shell, _PATH_BSHELL) == 0) {
1079 sh_argv[1] = __DECONST(char*, "-o");
1080 sh_argv[2] = __DECONST(char*, "verify");
1081 sh_argv_len = 3;
1082 }
1083 #endif
1084 for (i = 0; i != SCRIPT_ARGV_SIZE; ++i)
1085 sh_argv[i + sh_argv_len] = argv[i];
1086 execv(shell, sh_argv);
1087 stall("can't exec %s for %s: %m", shell, script);
1088 }
1089
1090 /*
1091 * Execute binary, replacing init(8) as PID 1.
1092 */
1093 static void
replace_init(char * path)1094 replace_init(char *path)
1095 {
1096 char *argv[SCRIPT_ARGV_SIZE];
1097
1098 argv[0] = path;
1099 argv[1] = NULL;
1100
1101 execute_script(argv);
1102 }
1103
1104 /*
1105 * Run a shell script.
1106 * Returns 0 on success, otherwise the next transition to enter:
1107 * - single_user if fork/execv/waitpid failed, or if the script
1108 * terminated with a signal or exit code != 0.
1109 * - death_single if a SIGTERM was delivered to init(8).
1110 */
1111 static state_func_t
run_script(const char * script)1112 run_script(const char *script)
1113 {
1114 pid_t pid, wpid;
1115 int status;
1116 char *argv[SCRIPT_ARGV_SIZE];
1117 const char *shell;
1118
1119 shell = get_shell();
1120
1121 if ((pid = fork()) == 0) {
1122
1123 char _autoboot[] = "autoboot";
1124
1125 argv[0] = __DECONST(char *, script);
1126 argv[1] = runcom_mode == AUTOBOOT ? _autoboot : NULL;
1127 argv[2] = NULL;
1128
1129 execute_script(argv);
1130 sleep(STALL_TIMEOUT);
1131 _exit(1); /* force single user mode */
1132 }
1133
1134 if (pid == -1) {
1135 emergency("can't fork for %s on %s: %m", shell, script);
1136 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1137 continue;
1138 sleep(STALL_TIMEOUT);
1139 return (state_func_t) single_user;
1140 }
1141
1142 /*
1143 * Copied from single_user(). This is a bit paranoid.
1144 */
1145 requested_transition = 0;
1146 do {
1147 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1148 collect_child(wpid);
1149 if (requested_transition == death_single ||
1150 requested_transition == reroot)
1151 return (state_func_t) requested_transition;
1152 if (wpid == -1) {
1153 if (errno == EINTR)
1154 continue;
1155 warning("wait for %s on %s failed: %m; going to "
1156 "single user mode", shell, script);
1157 return (state_func_t) single_user;
1158 }
1159 if (wpid == pid && WIFSTOPPED(status)) {
1160 warning("init: %s on %s stopped, restarting\n",
1161 shell, script);
1162 kill(pid, SIGCONT);
1163 wpid = -1;
1164 }
1165 } while (wpid != pid);
1166
1167 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1168 requested_transition == catatonia) {
1169 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
1170 sigset_t s;
1171
1172 sigfillset(&s);
1173 for (;;)
1174 sigsuspend(&s);
1175 }
1176
1177 if (!WIFEXITED(status)) {
1178 warning("%s on %s terminated abnormally, going to single "
1179 "user mode", shell, script);
1180 return (state_func_t) single_user;
1181 }
1182
1183 if (WEXITSTATUS(status))
1184 return (state_func_t) single_user;
1185
1186 return (state_func_t) 0;
1187 }
1188
1189 /*
1190 * Open the session database.
1191 *
1192 * NB: We could pass in the size here; is it necessary?
1193 */
1194 static int
start_session_db(void)1195 start_session_db(void)
1196 {
1197 if (session_db && (*session_db->close)(session_db))
1198 emergency("session database close: %m");
1199 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) {
1200 emergency("session database open: %m");
1201 return (1);
1202 }
1203 return (0);
1204
1205 }
1206
1207 /*
1208 * Add a new login session.
1209 */
1210 static void
add_session(session_t * sp)1211 add_session(session_t *sp)
1212 {
1213 DBT key;
1214 DBT data;
1215
1216 key.data = &sp->se_process;
1217 key.size = sizeof sp->se_process;
1218 data.data = &sp;
1219 data.size = sizeof sp;
1220
1221 if ((*session_db->put)(session_db, &key, &data, 0))
1222 emergency("insert %d: %m", sp->se_process);
1223 }
1224
1225 /*
1226 * Delete an old login session.
1227 */
1228 static void
del_session(session_t * sp)1229 del_session(session_t *sp)
1230 {
1231 DBT key;
1232
1233 key.data = &sp->se_process;
1234 key.size = sizeof sp->se_process;
1235
1236 if ((*session_db->del)(session_db, &key, 0))
1237 emergency("delete %d: %m", sp->se_process);
1238 }
1239
1240 /*
1241 * Look up a login session by pid.
1242 */
1243 static session_t *
find_session(pid_t pid)1244 find_session(pid_t pid)
1245 {
1246 DBT key;
1247 DBT data;
1248 session_t *ret;
1249
1250 key.data = &pid;
1251 key.size = sizeof pid;
1252 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
1253 return 0;
1254 bcopy(data.data, (char *)&ret, sizeof(ret));
1255 return ret;
1256 }
1257
1258 /*
1259 * Construct an argument vector from a command line.
1260 */
1261 static char **
construct_argv(char * command)1262 construct_argv(char *command)
1263 {
1264 int argc = 0;
1265 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
1266 * sizeof (char *));
1267
1268 if ((argv[argc++] = strk(command)) == NULL) {
1269 free(argv);
1270 return (NULL);
1271 }
1272 while ((argv[argc++] = strk((char *) 0)) != NULL)
1273 continue;
1274 return argv;
1275 }
1276
1277 /*
1278 * Deallocate a session descriptor.
1279 */
1280 static void
free_session(session_t * sp)1281 free_session(session_t *sp)
1282 {
1283 free(sp->se_device);
1284 if (sp->se_getty) {
1285 free(sp->se_getty);
1286 free(sp->se_getty_argv_space);
1287 free(sp->se_getty_argv);
1288 }
1289 if (sp->se_window) {
1290 free(sp->se_window);
1291 free(sp->se_window_argv_space);
1292 free(sp->se_window_argv);
1293 }
1294 if (sp->se_type)
1295 free(sp->se_type);
1296 free(sp);
1297 }
1298
1299 /*
1300 * Allocate a new session descriptor.
1301 * Mark it SE_PRESENT.
1302 */
1303 static session_t *
new_session(session_t * sprev,struct ttyent * typ)1304 new_session(session_t *sprev, struct ttyent *typ)
1305 {
1306 session_t *sp;
1307
1308 if ((typ->ty_status & TTY_ON) == 0 ||
1309 typ->ty_name == 0 ||
1310 typ->ty_getty == 0)
1311 return 0;
1312
1313 sp = (session_t *) calloc(1, sizeof (session_t));
1314
1315 sp->se_flags |= SE_PRESENT;
1316
1317 if ((typ->ty_status & TTY_IFEXISTS) != 0)
1318 sp->se_flags |= SE_IFEXISTS;
1319
1320 if ((typ->ty_status & TTY_IFCONSOLE) != 0)
1321 sp->se_flags |= SE_IFCONSOLE;
1322
1323 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0)
1324 err(1, "asprintf");
1325
1326 if (setupargv(sp, typ) == 0) {
1327 free_session(sp);
1328 return (0);
1329 }
1330
1331 sp->se_next = 0;
1332 if (sprev == NULL) {
1333 sessions = sp;
1334 sp->se_prev = 0;
1335 } else {
1336 sprev->se_next = sp;
1337 sp->se_prev = sprev;
1338 }
1339
1340 return sp;
1341 }
1342
1343 /*
1344 * Calculate getty and if useful window argv vectors.
1345 */
1346 static int
setupargv(session_t * sp,struct ttyent * typ)1347 setupargv(session_t *sp, struct ttyent *typ)
1348 {
1349
1350 if (sp->se_getty) {
1351 free(sp->se_getty);
1352 free(sp->se_getty_argv_space);
1353 free(sp->se_getty_argv);
1354 }
1355 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0)
1356 err(1, "asprintf");
1357 sp->se_getty_argv_space = strdup(sp->se_getty);
1358 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1359 if (sp->se_getty_argv == NULL) {
1360 warning("can't parse getty for port %s", sp->se_device);
1361 free(sp->se_getty);
1362 free(sp->se_getty_argv_space);
1363 sp->se_getty = sp->se_getty_argv_space = 0;
1364 return (0);
1365 }
1366 if (sp->se_window) {
1367 free(sp->se_window);
1368 free(sp->se_window_argv_space);
1369 free(sp->se_window_argv);
1370 }
1371 sp->se_window = sp->se_window_argv_space = 0;
1372 sp->se_window_argv = 0;
1373 if (typ->ty_window) {
1374 sp->se_window = strdup(typ->ty_window);
1375 sp->se_window_argv_space = strdup(sp->se_window);
1376 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1377 if (sp->se_window_argv == NULL) {
1378 warning("can't parse window for port %s",
1379 sp->se_device);
1380 free(sp->se_window_argv_space);
1381 free(sp->se_window);
1382 sp->se_window = sp->se_window_argv_space = 0;
1383 return (0);
1384 }
1385 }
1386 if (sp->se_type)
1387 free(sp->se_type);
1388 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1389 return (1);
1390 }
1391
1392 /*
1393 * Walk the list of ttys and create sessions for each active line.
1394 */
1395 static state_func_t
read_ttys(void)1396 read_ttys(void)
1397 {
1398 session_t *sp, *snext;
1399 struct ttyent *typ;
1400
1401 /*
1402 * Destroy any previous session state.
1403 * There shouldn't be any, but just in case...
1404 */
1405 for (sp = sessions; sp; sp = snext) {
1406 snext = sp->se_next;
1407 free_session(sp);
1408 }
1409 sessions = 0;
1410 if (start_session_db())
1411 return (state_func_t) single_user;
1412
1413 /*
1414 * Allocate a session entry for each active port.
1415 * Note that sp starts at 0.
1416 */
1417 while ((typ = getttyent()) != NULL)
1418 if ((snext = new_session(sp, typ)) != NULL)
1419 sp = snext;
1420
1421 endttyent();
1422
1423 return (state_func_t) multi_user;
1424 }
1425
1426 /*
1427 * Start a window system running.
1428 */
1429 static void
start_window_system(session_t * sp)1430 start_window_system(session_t *sp)
1431 {
1432 pid_t pid;
1433 sigset_t mask;
1434 char term[64], *env[2];
1435 int status;
1436
1437 if ((pid = fork()) == -1) {
1438 emergency("can't fork for window system on port %s: %m",
1439 sp->se_device);
1440 /* hope that getty fails and we can try again */
1441 return;
1442 }
1443 if (pid) {
1444 waitpid(-1, &status, 0);
1445 return;
1446 }
1447
1448 /* reparent window process to the init to not make a zombie on exit */
1449 if ((pid = fork()) == -1) {
1450 emergency("can't fork for window system on port %s: %m",
1451 sp->se_device);
1452 _exit(1);
1453 }
1454 if (pid)
1455 _exit(0);
1456
1457 sigemptyset(&mask);
1458 sigprocmask(SIG_SETMASK, &mask, NULL);
1459
1460 if (setsid() < 0)
1461 emergency("setsid failed (window) %m");
1462
1463 #ifdef LOGIN_CAP
1464 setprocresources(RESOURCE_WINDOW);
1465 #endif
1466 if (sp->se_type) {
1467 /* Don't use malloc after fork */
1468 strcpy(term, "TERM=");
1469 strlcat(term, sp->se_type, sizeof(term));
1470 env[0] = term;
1471 env[1] = NULL;
1472 }
1473 else
1474 env[0] = NULL;
1475 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1476 stall("can't exec window system '%s' for port %s: %m",
1477 sp->se_window_argv[0], sp->se_device);
1478 _exit(1);
1479 }
1480
1481 /*
1482 * Start a login session running.
1483 */
1484 static pid_t
start_getty(session_t * sp)1485 start_getty(session_t *sp)
1486 {
1487 pid_t pid;
1488 sigset_t mask;
1489 time_t current_time = time((time_t *) 0);
1490 int too_quick = 0;
1491 char term[64], *env[2];
1492
1493 if (current_time >= sp->se_started &&
1494 current_time - sp->se_started < GETTY_SPACING) {
1495 if (++sp->se_nspace > GETTY_NSPACE) {
1496 sp->se_nspace = 0;
1497 too_quick = 1;
1498 }
1499 } else
1500 sp->se_nspace = 0;
1501
1502 /*
1503 * fork(), not vfork() -- we can't afford to block.
1504 */
1505 if ((pid = fork()) == -1) {
1506 emergency("can't fork for getty on port %s: %m", sp->se_device);
1507 return -1;
1508 }
1509
1510 if (pid)
1511 return pid;
1512
1513 if (too_quick) {
1514 warning("getty repeating too quickly on port %s, sleeping %d secs",
1515 sp->se_device, GETTY_SLEEP);
1516 sleep((unsigned) GETTY_SLEEP);
1517 }
1518
1519 if (sp->se_window) {
1520 start_window_system(sp);
1521 sleep(WINDOW_WAIT);
1522 }
1523
1524 sigemptyset(&mask);
1525 sigprocmask(SIG_SETMASK, &mask, NULL);
1526
1527 #ifdef LOGIN_CAP
1528 setprocresources(RESOURCE_GETTY);
1529 #endif
1530 if (sp->se_type) {
1531 /* Don't use malloc after fork */
1532 strcpy(term, "TERM=");
1533 strlcat(term, sp->se_type, sizeof(term));
1534 env[0] = term;
1535 env[1] = NULL;
1536 } else
1537 env[0] = NULL;
1538 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1539 stall("can't exec getty '%s' for port %s: %m",
1540 sp->se_getty_argv[0], sp->se_device);
1541 _exit(1);
1542 }
1543
1544 /*
1545 * Return 1 if the session is defined as "onifexists"
1546 * or "onifconsole" and the device node does not exist.
1547 */
1548 static int
session_has_no_tty(session_t * sp)1549 session_has_no_tty(session_t *sp)
1550 {
1551 int fd;
1552
1553 if ((sp->se_flags & SE_IFEXISTS) == 0 &&
1554 (sp->se_flags & SE_IFCONSOLE) == 0)
1555 return (0);
1556
1557 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0);
1558 if (fd < 0) {
1559 if (errno == ENOENT)
1560 return (1);
1561 return (0);
1562 }
1563
1564 close(fd);
1565 return (0);
1566 }
1567
1568 /*
1569 * Collect exit status for a child.
1570 * If an exiting login, start a new login running.
1571 */
1572 static void
collect_child(pid_t pid)1573 collect_child(pid_t pid)
1574 {
1575 session_t *sp, *sprev, *snext;
1576
1577 if (! sessions)
1578 return;
1579
1580 if (! (sp = find_session(pid)))
1581 return;
1582
1583 del_session(sp);
1584 sp->se_process = 0;
1585
1586 if (sp->se_flags & SE_SHUTDOWN ||
1587 session_has_no_tty(sp)) {
1588 if ((sprev = sp->se_prev) != NULL)
1589 sprev->se_next = sp->se_next;
1590 else
1591 sessions = sp->se_next;
1592 if ((snext = sp->se_next) != NULL)
1593 snext->se_prev = sp->se_prev;
1594 free_session(sp);
1595 return;
1596 }
1597
1598 if ((pid = start_getty(sp)) == -1) {
1599 /* serious trouble */
1600 requested_transition = clean_ttys;
1601 return;
1602 }
1603
1604 sp->se_process = pid;
1605 sp->se_started = time((time_t *) 0);
1606 add_session(sp);
1607 }
1608
1609 static const char *
get_current_state(void)1610 get_current_state(void)
1611 {
1612
1613 if (current_state == single_user)
1614 return ("single-user");
1615 if (current_state == runcom)
1616 return ("runcom");
1617 if (current_state == read_ttys)
1618 return ("read-ttys");
1619 if (current_state == multi_user)
1620 return ("multi-user");
1621 if (current_state == clean_ttys)
1622 return ("clean-ttys");
1623 if (current_state == catatonia)
1624 return ("catatonia");
1625 if (current_state == death)
1626 return ("death");
1627 if (current_state == death_single)
1628 return ("death-single");
1629 return ("unknown");
1630 }
1631
1632 static void
boottrace_transition(int sig)1633 boottrace_transition(int sig)
1634 {
1635 const char *action;
1636
1637 switch (sig) {
1638 case SIGUSR2:
1639 action = "halt & poweroff";
1640 break;
1641 case SIGUSR1:
1642 action = "halt";
1643 break;
1644 case SIGINT:
1645 action = "reboot";
1646 break;
1647 case SIGWINCH:
1648 action = "powercycle";
1649 break;
1650 case SIGTERM:
1651 action = Reboot ? "reboot" : "single-user";
1652 break;
1653 default:
1654 BOOTTRACE("signal %d from %s", sig, get_current_state());
1655 return;
1656 }
1657
1658 /* Trace the shutdown reason. */
1659 SHUTTRACE("%s from %s", action, get_current_state());
1660 }
1661
1662 /*
1663 * Catch a signal and request a state transition.
1664 */
1665 static void
transition_handler(int sig)1666 transition_handler(int sig)
1667 {
1668
1669 boottrace_transition(sig);
1670 switch (sig) {
1671 case SIGHUP:
1672 if (current_state == read_ttys || current_state == multi_user ||
1673 current_state == clean_ttys || current_state == catatonia)
1674 requested_transition = clean_ttys;
1675 break;
1676 case SIGUSR2:
1677 howto = RB_POWEROFF;
1678 case SIGUSR1:
1679 howto |= RB_HALT;
1680 case SIGWINCH:
1681 case SIGINT:
1682 if (sig == SIGWINCH)
1683 howto |= RB_POWERCYCLE;
1684 Reboot = true;
1685 case SIGTERM:
1686 if (current_state == read_ttys || current_state == multi_user ||
1687 current_state == clean_ttys || current_state == catatonia)
1688 requested_transition = death;
1689 else
1690 requested_transition = death_single;
1691 break;
1692 case SIGTSTP:
1693 if (current_state == runcom || current_state == read_ttys ||
1694 current_state == clean_ttys ||
1695 current_state == multi_user || current_state == catatonia)
1696 requested_transition = catatonia;
1697 break;
1698 case SIGEMT:
1699 requested_transition = reroot;
1700 break;
1701 default:
1702 requested_transition = 0;
1703 break;
1704 }
1705 }
1706
1707 /*
1708 * Take the system multiuser.
1709 */
1710 static state_func_t
multi_user(void)1711 multi_user(void)
1712 {
1713 static bool inmultiuser = false;
1714 pid_t pid;
1715 session_t *sp;
1716
1717 requested_transition = 0;
1718
1719 /*
1720 * If the administrator has not set the security level to -1
1721 * to indicate that the kernel should not run multiuser in secure
1722 * mode, and the run script has not set a higher level of security
1723 * than level 1, then put the kernel into secure mode.
1724 */
1725 if (getsecuritylevel() == 0)
1726 setsecuritylevel(1);
1727
1728 for (sp = sessions; sp; sp = sp->se_next) {
1729 if (sp->se_process)
1730 continue;
1731 if (session_has_no_tty(sp))
1732 continue;
1733 if ((pid = start_getty(sp)) == -1) {
1734 /* serious trouble */
1735 requested_transition = clean_ttys;
1736 break;
1737 }
1738 sp->se_process = pid;
1739 sp->se_started = time((time_t *) 0);
1740 add_session(sp);
1741 }
1742
1743 if (requested_transition == 0 && !inmultiuser) {
1744 inmultiuser = true;
1745 /* This marks the change from boot-time tracing to run-time. */
1746 RUNTRACE("multi-user start");
1747 }
1748 while (!requested_transition)
1749 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1750 collect_child(pid);
1751
1752 return (state_func_t) requested_transition;
1753 }
1754
1755 /*
1756 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1757 */
1758 static state_func_t
clean_ttys(void)1759 clean_ttys(void)
1760 {
1761 session_t *sp, *sprev;
1762 struct ttyent *typ;
1763 int devlen;
1764 char *old_getty, *old_window, *old_type;
1765
1766 /*
1767 * mark all sessions for death, (!SE_PRESENT)
1768 * as we find or create new ones they'll be marked as keepers,
1769 * we'll later nuke all the ones not found in /etc/ttys
1770 */
1771 for (sp = sessions; sp != NULL; sp = sp->se_next)
1772 sp->se_flags &= ~SE_PRESENT;
1773
1774 devlen = sizeof(_PATH_DEV) - 1;
1775 while ((typ = getttyent()) != NULL) {
1776 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1777 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1778 break;
1779
1780 if (sp) {
1781 /* we want this one to live */
1782 sp->se_flags |= SE_PRESENT;
1783 if ((typ->ty_status & TTY_ON) == 0 ||
1784 typ->ty_getty == 0) {
1785 sp->se_flags |= SE_SHUTDOWN;
1786 kill(sp->se_process, SIGHUP);
1787 continue;
1788 }
1789 sp->se_flags &= ~SE_SHUTDOWN;
1790 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1791 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1792 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1793 if (setupargv(sp, typ) == 0) {
1794 warning("can't parse getty for port %s",
1795 sp->se_device);
1796 sp->se_flags |= SE_SHUTDOWN;
1797 kill(sp->se_process, SIGHUP);
1798 }
1799 else if ( !old_getty
1800 || (!old_type && sp->se_type)
1801 || (old_type && !sp->se_type)
1802 || (!old_window && sp->se_window)
1803 || (old_window && !sp->se_window)
1804 || (strcmp(old_getty, sp->se_getty) != 0)
1805 || (old_window && strcmp(old_window, sp->se_window) != 0)
1806 || (old_type && strcmp(old_type, sp->se_type) != 0)
1807 ) {
1808 /* Don't set SE_SHUTDOWN here */
1809 sp->se_nspace = 0;
1810 sp->se_started = 0;
1811 kill(sp->se_process, SIGHUP);
1812 }
1813 if (old_getty)
1814 free(old_getty);
1815 if (old_window)
1816 free(old_window);
1817 if (old_type)
1818 free(old_type);
1819 continue;
1820 }
1821
1822 new_session(sprev, typ);
1823 }
1824
1825 endttyent();
1826
1827 /*
1828 * sweep through and kill all deleted sessions
1829 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1830 */
1831 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1832 if ((sp->se_flags & SE_PRESENT) == 0) {
1833 sp->se_flags |= SE_SHUTDOWN;
1834 kill(sp->se_process, SIGHUP);
1835 }
1836 }
1837
1838 return (state_func_t) multi_user;
1839 }
1840
1841 /*
1842 * Block further logins.
1843 */
1844 static state_func_t
catatonia(void)1845 catatonia(void)
1846 {
1847 session_t *sp;
1848
1849 for (sp = sessions; sp; sp = sp->se_next)
1850 sp->se_flags |= SE_SHUTDOWN;
1851
1852 return (state_func_t) multi_user;
1853 }
1854
1855 /*
1856 * Note SIGALRM.
1857 */
1858 static void
alrm_handler(int sig)1859 alrm_handler(int sig)
1860 {
1861
1862 (void)sig;
1863 clang = true;
1864 }
1865
1866 /*
1867 * Bring the system down to single user.
1868 */
1869 static state_func_t
death(void)1870 death(void)
1871 {
1872 int block, blocked;
1873 size_t len;
1874
1875 /* Temporarily block suspend. */
1876 len = sizeof(blocked);
1877 block = 1;
1878 if (sysctlbyname("kern.suspend_blocked", &blocked, &len,
1879 &block, sizeof(block)) == -1)
1880 blocked = 0;
1881
1882 /*
1883 * Also revoke the TTY here. Because runshutdown() may reopen
1884 * the TTY whose getty we're killing here, there is no guarantee
1885 * runshutdown() will perform the initial open() call, causing
1886 * the terminal attributes to be misconfigured.
1887 */
1888 revoke_ttys();
1889
1890 /* Try to run the rc.shutdown script within a period of time */
1891 runshutdown();
1892
1893 /* Unblock suspend if we blocked it. */
1894 if (!blocked)
1895 sysctlbyname("kern.suspend_blocked", NULL, NULL,
1896 &blocked, sizeof(blocked));
1897
1898 return (state_func_t) death_single;
1899 }
1900
1901 /*
1902 * Do what is necessary to reinitialize single user mode or reboot
1903 * from an incomplete state.
1904 */
1905 static state_func_t
death_single(void)1906 death_single(void)
1907 {
1908 int i;
1909 pid_t pid;
1910 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1911
1912 revoke(_PATH_CONSOLE);
1913
1914 BOOTTRACE("start killing user processes");
1915 for (i = 0; i < 2; ++i) {
1916 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1917 return (state_func_t) single_user;
1918
1919 clang = false;
1920 alarm(DEATH_WATCH);
1921 do
1922 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1923 collect_child(pid);
1924 while (!clang && errno != ECHILD);
1925
1926 if (errno == ECHILD)
1927 return (state_func_t) single_user;
1928 }
1929
1930 warning("some processes would not die; ps axl advised");
1931
1932 return (state_func_t) single_user;
1933 }
1934
1935 static void
revoke_ttys(void)1936 revoke_ttys(void)
1937 {
1938 session_t *sp;
1939
1940 for (sp = sessions; sp; sp = sp->se_next) {
1941 sp->se_flags |= SE_SHUTDOWN;
1942 kill(sp->se_process, SIGHUP);
1943 revoke(sp->se_device);
1944 }
1945 }
1946
1947 /*
1948 * Run the system shutdown script.
1949 *
1950 * Exit codes: XXX I should document more
1951 * -2 shutdown script terminated abnormally
1952 * -1 fatal error - can't run script
1953 * 0 good.
1954 * >0 some error (exit code)
1955 */
1956 static int
runshutdown(void)1957 runshutdown(void)
1958 {
1959 pid_t pid, wpid;
1960 int status;
1961 int shutdowntimeout;
1962 size_t len;
1963 char *argv[SCRIPT_ARGV_SIZE];
1964 struct stat sb;
1965
1966 BOOTTRACE("init(8): start rc.shutdown");
1967
1968 /*
1969 * rc.shutdown is optional, so to prevent any unnecessary
1970 * complaints from the shell we simply don't run it if the
1971 * file does not exist. If the stat() here fails for other
1972 * reasons, we'll let the shell complain.
1973 */
1974 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1975 return 0;
1976
1977 if ((pid = fork()) == 0) {
1978 char _reboot[] = "reboot";
1979 char _single[] = "single";
1980 char _path_rundown[] = _PATH_RUNDOWN;
1981
1982 argv[0] = _path_rundown;
1983 argv[1] = Reboot ? _reboot : _single;
1984 argv[2] = NULL;
1985
1986 execute_script(argv);
1987 _exit(1); /* force single user mode */
1988 }
1989
1990 if (pid == -1) {
1991 emergency("can't fork for %s: %m", _PATH_RUNDOWN);
1992 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1993 continue;
1994 sleep(STALL_TIMEOUT);
1995 return -1;
1996 }
1997
1998 len = sizeof(shutdowntimeout);
1999 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
2000 NULL, 0) == -1 || shutdowntimeout < 2)
2001 shutdowntimeout = DEATH_SCRIPT;
2002 alarm(shutdowntimeout);
2003 clang = false;
2004 /*
2005 * Copied from single_user(). This is a bit paranoid.
2006 * Use the same ALRM handler.
2007 */
2008 do {
2009 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
2010 collect_child(wpid);
2011 if (clang) {
2012 /* we were waiting for the sub-shell */
2013 kill(wpid, SIGTERM);
2014 warning("timeout expired for %s: %m; going to "
2015 "single user mode", _PATH_RUNDOWN);
2016 BOOTTRACE("rc.shutdown's %d sec timeout expired",
2017 shutdowntimeout);
2018 return -1;
2019 }
2020 if (wpid == -1) {
2021 if (errno == EINTR)
2022 continue;
2023 warning("wait for %s failed: %m; going to "
2024 "single user mode", _PATH_RUNDOWN);
2025 return -1;
2026 }
2027 if (wpid == pid && WIFSTOPPED(status)) {
2028 warning("init: %s stopped, restarting\n",
2029 _PATH_RUNDOWN);
2030 kill(pid, SIGCONT);
2031 wpid = -1;
2032 }
2033 } while (wpid != pid && !clang);
2034
2035 /* Turn off the alarm */
2036 alarm(0);
2037
2038 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
2039 requested_transition == catatonia) {
2040 /*
2041 * /etc/rc.shutdown executed /sbin/reboot;
2042 * wait for the end quietly
2043 */
2044 sigset_t s;
2045
2046 sigfillset(&s);
2047 for (;;)
2048 sigsuspend(&s);
2049 }
2050
2051 if (!WIFEXITED(status)) {
2052 warning("%s terminated abnormally, going to "
2053 "single user mode", _PATH_RUNDOWN);
2054 return -2;
2055 }
2056
2057 if ((status = WEXITSTATUS(status)) != 0)
2058 warning("%s returned status %d", _PATH_RUNDOWN, status);
2059
2060 return status;
2061 }
2062
2063 static char *
strk(char * p)2064 strk(char *p)
2065 {
2066 static char *t;
2067 char *q;
2068 int c;
2069
2070 if (p)
2071 t = p;
2072 if (!t)
2073 return 0;
2074
2075 c = *t;
2076 while (c == ' ' || c == '\t' )
2077 c = *++t;
2078 if (!c) {
2079 t = 0;
2080 return 0;
2081 }
2082 q = t;
2083 if (c == '\'') {
2084 c = *++t;
2085 q = t;
2086 while (c && c != '\'')
2087 c = *++t;
2088 if (!c) /* unterminated string */
2089 q = t = 0;
2090 else
2091 *t++ = 0;
2092 } else {
2093 while (c && c != ' ' && c != '\t' )
2094 c = *++t;
2095 *t++ = 0;
2096 if (!c)
2097 t = 0;
2098 }
2099 return q;
2100 }
2101
2102 #ifdef LOGIN_CAP
2103 static void
setprocresources(const char * cname)2104 setprocresources(const char *cname)
2105 {
2106 login_cap_t *lc;
2107 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
2108 setusercontext(lc, (struct passwd*)NULL, 0,
2109 LOGIN_SETENV |
2110 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
2111 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
2112 login_close(lc);
2113 }
2114 }
2115 #endif
2116
2117 /*
2118 * Run /etc/rc.final to execute scripts after all user processes have been
2119 * terminated.
2120 */
2121 static void
runfinal(void)2122 runfinal(void)
2123 {
2124 struct stat sb;
2125 pid_t other_pid, pid;
2126 sigset_t mask;
2127
2128 /* Avoid any surprises. */
2129 alarm(0);
2130
2131 /* rc.final is optional. */
2132 if (stat(_PATH_RUNFINAL, &sb) == -1 && errno == ENOENT)
2133 return;
2134 if (access(_PATH_RUNFINAL, X_OK) != 0) {
2135 warning("%s exists, but not executable", _PATH_RUNFINAL);
2136 return;
2137 }
2138
2139 pid = fork();
2140 if (pid == 0) {
2141 /*
2142 * Reopen stdin/stdout/stderr so that scripts can write to
2143 * console.
2144 */
2145 close(0);
2146 open(_PATH_DEVNULL, O_RDONLY);
2147 close(1);
2148 close(2);
2149 open_console();
2150 dup2(1, 2);
2151 sigemptyset(&mask);
2152 sigprocmask(SIG_SETMASK, &mask, NULL);
2153 signal(SIGCHLD, SIG_DFL);
2154 execl(_PATH_RUNFINAL, _PATH_RUNFINAL, NULL);
2155 perror("execl(" _PATH_RUNFINAL ") failed");
2156 exit(1);
2157 }
2158
2159 /* Wait for rc.final script to exit */
2160 while ((other_pid = waitpid(-1, NULL, 0)) != pid && other_pid > 0) {
2161 continue;
2162 }
2163 }
2164