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 char runcom_path[PATH_MAX];
1029 const char *rc_script;
1030
1031 /*
1032 * Allow overriding /etc/rc via the init_rc kenv variable.
1033 * This is useful for testing alternative service managers
1034 * without modifying /etc/rc.
1035 */
1036 if (kenv(KENV_GET, "init_rc", runcom_path, sizeof(runcom_path)) > 0)
1037 rc_script = runcom_path;
1038 else
1039 rc_script = _PATH_RUNCOM;
1040
1041 BOOTTRACE("%s starting...", rc_script);
1042 if ((next_transition = run_script(rc_script)) != NULL)
1043 return next_transition;
1044 BOOTTRACE("%s finished", rc_script);
1045
1046 runcom_mode = AUTOBOOT; /* the default */
1047 return (state_func_t) read_ttys;
1048 }
1049
1050 static void
execute_script(char * argv[])1051 execute_script(char *argv[])
1052 {
1053 struct sigaction sa;
1054 char* sh_argv[3 + SCRIPT_ARGV_SIZE];
1055 const char *shell, *script;
1056 int error, sh_argv_len, i;
1057
1058 bzero(&sa, sizeof(sa));
1059 sigemptyset(&sa.sa_mask);
1060 sa.sa_handler = SIG_IGN;
1061 sigaction(SIGTSTP, &sa, NULL);
1062 sigaction(SIGHUP, &sa, NULL);
1063
1064 open_console();
1065
1066 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1067 #ifdef LOGIN_CAP
1068 setprocresources(RESOURCE_RC);
1069 #endif
1070
1071 /*
1072 * Try to directly execute the script first. If it
1073 * fails, try the old method of passing the script path
1074 * to sh(1). Don't complain if it fails because of
1075 * the missing execute bit.
1076 */
1077 script = argv[0];
1078 error = access(script, X_OK);
1079 if (error == 0) {
1080 execv(script, argv);
1081 warning("can't directly exec %s: %m", script);
1082 } else if (errno != EACCES) {
1083 warning("can't access %s: %m", script);
1084 }
1085
1086 shell = get_shell();
1087 sh_argv[0] = __DECONST(char*, shell);
1088 sh_argv_len = 1;
1089 #ifdef SECURE
1090 if (strcmp(shell, _PATH_BSHELL) == 0) {
1091 sh_argv[1] = __DECONST(char*, "-o");
1092 sh_argv[2] = __DECONST(char*, "verify");
1093 sh_argv_len = 3;
1094 }
1095 #endif
1096 for (i = 0; i != SCRIPT_ARGV_SIZE; ++i)
1097 sh_argv[i + sh_argv_len] = argv[i];
1098 execv(shell, sh_argv);
1099 stall("can't exec %s for %s: %m", shell, script);
1100 }
1101
1102 /*
1103 * Execute binary, replacing init(8) as PID 1.
1104 */
1105 static void
replace_init(char * path)1106 replace_init(char *path)
1107 {
1108 char *argv[SCRIPT_ARGV_SIZE];
1109
1110 argv[0] = path;
1111 argv[1] = NULL;
1112
1113 execute_script(argv);
1114 }
1115
1116 /*
1117 * Run a shell script.
1118 * Returns 0 on success, otherwise the next transition to enter:
1119 * - single_user if fork/execv/waitpid failed, or if the script
1120 * terminated with a signal or exit code != 0.
1121 * - death_single if a SIGTERM was delivered to init(8).
1122 */
1123 static state_func_t
run_script(const char * script)1124 run_script(const char *script)
1125 {
1126 pid_t pid, wpid;
1127 int status;
1128 char *argv[SCRIPT_ARGV_SIZE];
1129 const char *shell;
1130
1131 shell = get_shell();
1132
1133 if ((pid = fork()) == 0) {
1134
1135 char _autoboot[] = "autoboot";
1136
1137 argv[0] = __DECONST(char *, script);
1138 argv[1] = runcom_mode == AUTOBOOT ? _autoboot : NULL;
1139 argv[2] = NULL;
1140
1141 execute_script(argv);
1142 sleep(STALL_TIMEOUT);
1143 _exit(1); /* force single user mode */
1144 }
1145
1146 if (pid == -1) {
1147 emergency("can't fork for %s on %s: %m", shell, script);
1148 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1149 continue;
1150 sleep(STALL_TIMEOUT);
1151 return (state_func_t) single_user;
1152 }
1153
1154 /*
1155 * Copied from single_user(). This is a bit paranoid.
1156 */
1157 requested_transition = 0;
1158 do {
1159 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1160 collect_child(wpid);
1161 if (requested_transition == death_single ||
1162 requested_transition == reroot)
1163 return (state_func_t) requested_transition;
1164 if (wpid == -1) {
1165 if (errno == EINTR)
1166 continue;
1167 warning("wait for %s on %s failed: %m; going to "
1168 "single user mode", shell, script);
1169 return (state_func_t) single_user;
1170 }
1171 if (wpid == pid && WIFSTOPPED(status)) {
1172 warning("init: %s on %s stopped, restarting\n",
1173 shell, script);
1174 kill(pid, SIGCONT);
1175 wpid = -1;
1176 }
1177 } while (wpid != pid);
1178
1179 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1180 requested_transition == catatonia) {
1181 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
1182 sigset_t s;
1183
1184 sigfillset(&s);
1185 for (;;)
1186 sigsuspend(&s);
1187 }
1188
1189 if (!WIFEXITED(status)) {
1190 warning("%s on %s terminated abnormally, going to single "
1191 "user mode", shell, script);
1192 return (state_func_t) single_user;
1193 }
1194
1195 if (WEXITSTATUS(status))
1196 return (state_func_t) single_user;
1197
1198 return (state_func_t) 0;
1199 }
1200
1201 /*
1202 * Open the session database.
1203 *
1204 * NB: We could pass in the size here; is it necessary?
1205 */
1206 static int
start_session_db(void)1207 start_session_db(void)
1208 {
1209 if (session_db && (*session_db->close)(session_db))
1210 emergency("session database close: %m");
1211 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) {
1212 emergency("session database open: %m");
1213 return (1);
1214 }
1215 return (0);
1216
1217 }
1218
1219 /*
1220 * Add a new login session.
1221 */
1222 static void
add_session(session_t * sp)1223 add_session(session_t *sp)
1224 {
1225 DBT key;
1226 DBT data;
1227
1228 key.data = &sp->se_process;
1229 key.size = sizeof sp->se_process;
1230 data.data = &sp;
1231 data.size = sizeof sp;
1232
1233 if ((*session_db->put)(session_db, &key, &data, 0))
1234 emergency("insert %d: %m", sp->se_process);
1235 }
1236
1237 /*
1238 * Delete an old login session.
1239 */
1240 static void
del_session(session_t * sp)1241 del_session(session_t *sp)
1242 {
1243 DBT key;
1244
1245 key.data = &sp->se_process;
1246 key.size = sizeof sp->se_process;
1247
1248 if ((*session_db->del)(session_db, &key, 0))
1249 emergency("delete %d: %m", sp->se_process);
1250 }
1251
1252 /*
1253 * Look up a login session by pid.
1254 */
1255 static session_t *
find_session(pid_t pid)1256 find_session(pid_t pid)
1257 {
1258 DBT key;
1259 DBT data;
1260 session_t *ret;
1261
1262 key.data = &pid;
1263 key.size = sizeof pid;
1264 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
1265 return 0;
1266 bcopy(data.data, (char *)&ret, sizeof(ret));
1267 return ret;
1268 }
1269
1270 /*
1271 * Construct an argument vector from a command line.
1272 */
1273 static char **
construct_argv(char * command)1274 construct_argv(char *command)
1275 {
1276 int argc = 0;
1277 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
1278 * sizeof (char *));
1279
1280 if ((argv[argc++] = strk(command)) == NULL) {
1281 free(argv);
1282 return (NULL);
1283 }
1284 while ((argv[argc++] = strk((char *) 0)) != NULL)
1285 continue;
1286 return argv;
1287 }
1288
1289 /*
1290 * Deallocate a session descriptor.
1291 */
1292 static void
free_session(session_t * sp)1293 free_session(session_t *sp)
1294 {
1295 free(sp->se_device);
1296 if (sp->se_getty) {
1297 free(sp->se_getty);
1298 free(sp->se_getty_argv_space);
1299 free(sp->se_getty_argv);
1300 }
1301 if (sp->se_window) {
1302 free(sp->se_window);
1303 free(sp->se_window_argv_space);
1304 free(sp->se_window_argv);
1305 }
1306 if (sp->se_type)
1307 free(sp->se_type);
1308 free(sp);
1309 }
1310
1311 /*
1312 * Allocate a new session descriptor.
1313 * Mark it SE_PRESENT.
1314 */
1315 static session_t *
new_session(session_t * sprev,struct ttyent * typ)1316 new_session(session_t *sprev, struct ttyent *typ)
1317 {
1318 session_t *sp;
1319
1320 if ((typ->ty_status & TTY_ON) == 0 ||
1321 typ->ty_name == 0 ||
1322 typ->ty_getty == 0)
1323 return 0;
1324
1325 sp = (session_t *) calloc(1, sizeof (session_t));
1326
1327 sp->se_flags |= SE_PRESENT;
1328
1329 if ((typ->ty_status & TTY_IFEXISTS) != 0)
1330 sp->se_flags |= SE_IFEXISTS;
1331
1332 if ((typ->ty_status & TTY_IFCONSOLE) != 0)
1333 sp->se_flags |= SE_IFCONSOLE;
1334
1335 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0)
1336 err(1, "asprintf");
1337
1338 if (setupargv(sp, typ) == 0) {
1339 free_session(sp);
1340 return (0);
1341 }
1342
1343 sp->se_next = 0;
1344 if (sprev == NULL) {
1345 sessions = sp;
1346 sp->se_prev = 0;
1347 } else {
1348 sprev->se_next = sp;
1349 sp->se_prev = sprev;
1350 }
1351
1352 return sp;
1353 }
1354
1355 /*
1356 * Calculate getty and if useful window argv vectors.
1357 */
1358 static int
setupargv(session_t * sp,struct ttyent * typ)1359 setupargv(session_t *sp, struct ttyent *typ)
1360 {
1361
1362 if (sp->se_getty) {
1363 free(sp->se_getty);
1364 free(sp->se_getty_argv_space);
1365 free(sp->se_getty_argv);
1366 }
1367 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0)
1368 err(1, "asprintf");
1369 sp->se_getty_argv_space = strdup(sp->se_getty);
1370 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1371 if (sp->se_getty_argv == NULL) {
1372 warning("can't parse getty for port %s", sp->se_device);
1373 free(sp->se_getty);
1374 free(sp->se_getty_argv_space);
1375 sp->se_getty = sp->se_getty_argv_space = 0;
1376 return (0);
1377 }
1378 if (sp->se_window) {
1379 free(sp->se_window);
1380 free(sp->se_window_argv_space);
1381 free(sp->se_window_argv);
1382 }
1383 sp->se_window = sp->se_window_argv_space = 0;
1384 sp->se_window_argv = 0;
1385 if (typ->ty_window) {
1386 sp->se_window = strdup(typ->ty_window);
1387 sp->se_window_argv_space = strdup(sp->se_window);
1388 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1389 if (sp->se_window_argv == NULL) {
1390 warning("can't parse window for port %s",
1391 sp->se_device);
1392 free(sp->se_window_argv_space);
1393 free(sp->se_window);
1394 sp->se_window = sp->se_window_argv_space = 0;
1395 return (0);
1396 }
1397 }
1398 if (sp->se_type)
1399 free(sp->se_type);
1400 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1401 return (1);
1402 }
1403
1404 /*
1405 * Walk the list of ttys and create sessions for each active line.
1406 */
1407 static state_func_t
read_ttys(void)1408 read_ttys(void)
1409 {
1410 session_t *sp, *snext;
1411 struct ttyent *typ;
1412
1413 /*
1414 * Destroy any previous session state.
1415 * There shouldn't be any, but just in case...
1416 */
1417 for (sp = sessions; sp; sp = snext) {
1418 snext = sp->se_next;
1419 free_session(sp);
1420 }
1421 sessions = 0;
1422 if (start_session_db())
1423 return (state_func_t) single_user;
1424
1425 /*
1426 * Allocate a session entry for each active port.
1427 * Note that sp starts at 0.
1428 */
1429 while ((typ = getttyent()) != NULL)
1430 if ((snext = new_session(sp, typ)) != NULL)
1431 sp = snext;
1432
1433 endttyent();
1434
1435 return (state_func_t) multi_user;
1436 }
1437
1438 /*
1439 * Start a window system running.
1440 */
1441 static void
start_window_system(session_t * sp)1442 start_window_system(session_t *sp)
1443 {
1444 pid_t pid;
1445 sigset_t mask;
1446 char term[64], *env[2];
1447 int status;
1448
1449 if ((pid = fork()) == -1) {
1450 emergency("can't fork for window system on port %s: %m",
1451 sp->se_device);
1452 /* hope that getty fails and we can try again */
1453 return;
1454 }
1455 if (pid) {
1456 waitpid(-1, &status, 0);
1457 return;
1458 }
1459
1460 /* reparent window process to the init to not make a zombie on exit */
1461 if ((pid = fork()) == -1) {
1462 emergency("can't fork for window system on port %s: %m",
1463 sp->se_device);
1464 _exit(1);
1465 }
1466 if (pid)
1467 _exit(0);
1468
1469 sigemptyset(&mask);
1470 sigprocmask(SIG_SETMASK, &mask, NULL);
1471
1472 if (setsid() < 0)
1473 emergency("setsid failed (window) %m");
1474
1475 #ifdef LOGIN_CAP
1476 setprocresources(RESOURCE_WINDOW);
1477 #endif
1478 if (sp->se_type) {
1479 /* Don't use malloc after fork */
1480 strcpy(term, "TERM=");
1481 strlcat(term, sp->se_type, sizeof(term));
1482 env[0] = term;
1483 env[1] = NULL;
1484 }
1485 else
1486 env[0] = NULL;
1487 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1488 stall("can't exec window system '%s' for port %s: %m",
1489 sp->se_window_argv[0], sp->se_device);
1490 _exit(1);
1491 }
1492
1493 /*
1494 * Start a login session running.
1495 */
1496 static pid_t
start_getty(session_t * sp)1497 start_getty(session_t *sp)
1498 {
1499 pid_t pid;
1500 sigset_t mask;
1501 time_t current_time = time((time_t *) 0);
1502 int too_quick = 0;
1503 char term[64], *env[2];
1504
1505 if (current_time >= sp->se_started &&
1506 current_time - sp->se_started < GETTY_SPACING) {
1507 if (++sp->se_nspace > GETTY_NSPACE) {
1508 sp->se_nspace = 0;
1509 too_quick = 1;
1510 }
1511 } else
1512 sp->se_nspace = 0;
1513
1514 /*
1515 * fork(), not vfork() -- we can't afford to block.
1516 */
1517 if ((pid = fork()) == -1) {
1518 emergency("can't fork for getty on port %s: %m", sp->se_device);
1519 return -1;
1520 }
1521
1522 if (pid)
1523 return pid;
1524
1525 if (too_quick) {
1526 warning("getty repeating too quickly on port %s, sleeping %d secs",
1527 sp->se_device, GETTY_SLEEP);
1528 sleep((unsigned) GETTY_SLEEP);
1529 }
1530
1531 if (sp->se_window) {
1532 start_window_system(sp);
1533 sleep(WINDOW_WAIT);
1534 }
1535
1536 sigemptyset(&mask);
1537 sigprocmask(SIG_SETMASK, &mask, NULL);
1538
1539 #ifdef LOGIN_CAP
1540 setprocresources(RESOURCE_GETTY);
1541 #endif
1542 if (sp->se_type) {
1543 /* Don't use malloc after fork */
1544 strcpy(term, "TERM=");
1545 strlcat(term, sp->se_type, sizeof(term));
1546 env[0] = term;
1547 env[1] = NULL;
1548 } else
1549 env[0] = NULL;
1550 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1551 stall("can't exec getty '%s' for port %s: %m",
1552 sp->se_getty_argv[0], sp->se_device);
1553 _exit(1);
1554 }
1555
1556 /*
1557 * Return 1 if the session is defined as "onifexists"
1558 * or "onifconsole" and the device node does not exist.
1559 */
1560 static int
session_has_no_tty(session_t * sp)1561 session_has_no_tty(session_t *sp)
1562 {
1563 int fd;
1564
1565 if ((sp->se_flags & SE_IFEXISTS) == 0 &&
1566 (sp->se_flags & SE_IFCONSOLE) == 0)
1567 return (0);
1568
1569 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0);
1570 if (fd < 0) {
1571 if (errno == ENOENT)
1572 return (1);
1573 return (0);
1574 }
1575
1576 close(fd);
1577 return (0);
1578 }
1579
1580 /*
1581 * Collect exit status for a child.
1582 * If an exiting login, start a new login running.
1583 */
1584 static void
collect_child(pid_t pid)1585 collect_child(pid_t pid)
1586 {
1587 session_t *sp, *sprev, *snext;
1588
1589 if (! sessions)
1590 return;
1591
1592 if (! (sp = find_session(pid)))
1593 return;
1594
1595 del_session(sp);
1596 sp->se_process = 0;
1597
1598 if (sp->se_flags & SE_SHUTDOWN ||
1599 session_has_no_tty(sp)) {
1600 if ((sprev = sp->se_prev) != NULL)
1601 sprev->se_next = sp->se_next;
1602 else
1603 sessions = sp->se_next;
1604 if ((snext = sp->se_next) != NULL)
1605 snext->se_prev = sp->se_prev;
1606 free_session(sp);
1607 return;
1608 }
1609
1610 if ((pid = start_getty(sp)) == -1) {
1611 /* serious trouble */
1612 requested_transition = clean_ttys;
1613 return;
1614 }
1615
1616 sp->se_process = pid;
1617 sp->se_started = time((time_t *) 0);
1618 add_session(sp);
1619 }
1620
1621 static const char *
get_current_state(void)1622 get_current_state(void)
1623 {
1624
1625 if (current_state == single_user)
1626 return ("single-user");
1627 if (current_state == runcom)
1628 return ("runcom");
1629 if (current_state == read_ttys)
1630 return ("read-ttys");
1631 if (current_state == multi_user)
1632 return ("multi-user");
1633 if (current_state == clean_ttys)
1634 return ("clean-ttys");
1635 if (current_state == catatonia)
1636 return ("catatonia");
1637 if (current_state == death)
1638 return ("death");
1639 if (current_state == death_single)
1640 return ("death-single");
1641 return ("unknown");
1642 }
1643
1644 static void
boottrace_transition(int sig)1645 boottrace_transition(int sig)
1646 {
1647 const char *action;
1648
1649 switch (sig) {
1650 case SIGUSR2:
1651 action = "halt & poweroff";
1652 break;
1653 case SIGUSR1:
1654 action = "halt";
1655 break;
1656 case SIGINT:
1657 action = "reboot";
1658 break;
1659 case SIGWINCH:
1660 action = "powercycle";
1661 break;
1662 case SIGTERM:
1663 action = Reboot ? "reboot" : "single-user";
1664 break;
1665 default:
1666 BOOTTRACE("signal %d from %s", sig, get_current_state());
1667 return;
1668 }
1669
1670 /* Trace the shutdown reason. */
1671 SHUTTRACE("%s from %s", action, get_current_state());
1672 }
1673
1674 /*
1675 * Catch a signal and request a state transition.
1676 */
1677 static void
transition_handler(int sig)1678 transition_handler(int sig)
1679 {
1680
1681 boottrace_transition(sig);
1682 switch (sig) {
1683 case SIGHUP:
1684 if (current_state == read_ttys || current_state == multi_user ||
1685 current_state == clean_ttys || current_state == catatonia)
1686 requested_transition = clean_ttys;
1687 break;
1688 case SIGUSR2:
1689 howto = RB_POWEROFF;
1690 case SIGUSR1:
1691 howto |= RB_HALT;
1692 case SIGWINCH:
1693 case SIGINT:
1694 if (sig == SIGWINCH)
1695 howto |= RB_POWERCYCLE;
1696 Reboot = true;
1697 case SIGTERM:
1698 if (current_state == read_ttys || current_state == multi_user ||
1699 current_state == clean_ttys || current_state == catatonia)
1700 requested_transition = death;
1701 else
1702 requested_transition = death_single;
1703 break;
1704 case SIGTSTP:
1705 if (current_state == runcom || current_state == read_ttys ||
1706 current_state == clean_ttys ||
1707 current_state == multi_user || current_state == catatonia)
1708 requested_transition = catatonia;
1709 break;
1710 case SIGEMT:
1711 requested_transition = reroot;
1712 break;
1713 default:
1714 requested_transition = 0;
1715 break;
1716 }
1717 }
1718
1719 /*
1720 * Take the system multiuser.
1721 */
1722 static state_func_t
multi_user(void)1723 multi_user(void)
1724 {
1725 static bool inmultiuser = false;
1726 pid_t pid;
1727 session_t *sp;
1728
1729 requested_transition = 0;
1730
1731 /*
1732 * If the administrator has not set the security level to -1
1733 * to indicate that the kernel should not run multiuser in secure
1734 * mode, and the run script has not set a higher level of security
1735 * than level 1, then put the kernel into secure mode.
1736 */
1737 if (getsecuritylevel() == 0)
1738 setsecuritylevel(1);
1739
1740 for (sp = sessions; sp; sp = sp->se_next) {
1741 if (sp->se_process)
1742 continue;
1743 if (session_has_no_tty(sp))
1744 continue;
1745 if ((pid = start_getty(sp)) == -1) {
1746 /* serious trouble */
1747 requested_transition = clean_ttys;
1748 break;
1749 }
1750 sp->se_process = pid;
1751 sp->se_started = time((time_t *) 0);
1752 add_session(sp);
1753 }
1754
1755 if (requested_transition == 0 && !inmultiuser) {
1756 inmultiuser = true;
1757 /* This marks the change from boot-time tracing to run-time. */
1758 RUNTRACE("multi-user start");
1759 }
1760 while (!requested_transition)
1761 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1762 collect_child(pid);
1763
1764 return (state_func_t) requested_transition;
1765 }
1766
1767 /*
1768 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1769 */
1770 static state_func_t
clean_ttys(void)1771 clean_ttys(void)
1772 {
1773 session_t *sp, *sprev;
1774 struct ttyent *typ;
1775 int devlen;
1776 char *old_getty, *old_window, *old_type;
1777
1778 /*
1779 * mark all sessions for death, (!SE_PRESENT)
1780 * as we find or create new ones they'll be marked as keepers,
1781 * we'll later nuke all the ones not found in /etc/ttys
1782 */
1783 for (sp = sessions; sp != NULL; sp = sp->se_next)
1784 sp->se_flags &= ~SE_PRESENT;
1785
1786 devlen = sizeof(_PATH_DEV) - 1;
1787 while ((typ = getttyent()) != NULL) {
1788 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1789 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1790 break;
1791
1792 if (sp) {
1793 /* we want this one to live */
1794 sp->se_flags |= SE_PRESENT;
1795 if ((typ->ty_status & TTY_ON) == 0 ||
1796 typ->ty_getty == 0) {
1797 sp->se_flags |= SE_SHUTDOWN;
1798 kill(sp->se_process, SIGHUP);
1799 continue;
1800 }
1801 sp->se_flags &= ~SE_SHUTDOWN;
1802 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1803 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1804 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1805 if (setupargv(sp, typ) == 0) {
1806 warning("can't parse getty for port %s",
1807 sp->se_device);
1808 sp->se_flags |= SE_SHUTDOWN;
1809 kill(sp->se_process, SIGHUP);
1810 }
1811 else if ( !old_getty
1812 || (!old_type && sp->se_type)
1813 || (old_type && !sp->se_type)
1814 || (!old_window && sp->se_window)
1815 || (old_window && !sp->se_window)
1816 || (strcmp(old_getty, sp->se_getty) != 0)
1817 || (old_window && strcmp(old_window, sp->se_window) != 0)
1818 || (old_type && strcmp(old_type, sp->se_type) != 0)
1819 ) {
1820 /* Don't set SE_SHUTDOWN here */
1821 sp->se_nspace = 0;
1822 sp->se_started = 0;
1823 kill(sp->se_process, SIGHUP);
1824 }
1825 if (old_getty)
1826 free(old_getty);
1827 if (old_window)
1828 free(old_window);
1829 if (old_type)
1830 free(old_type);
1831 continue;
1832 }
1833
1834 new_session(sprev, typ);
1835 }
1836
1837 endttyent();
1838
1839 /*
1840 * sweep through and kill all deleted sessions
1841 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1842 */
1843 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1844 if ((sp->se_flags & SE_PRESENT) == 0) {
1845 sp->se_flags |= SE_SHUTDOWN;
1846 kill(sp->se_process, SIGHUP);
1847 }
1848 }
1849
1850 return (state_func_t) multi_user;
1851 }
1852
1853 /*
1854 * Block further logins.
1855 */
1856 static state_func_t
catatonia(void)1857 catatonia(void)
1858 {
1859 session_t *sp;
1860
1861 for (sp = sessions; sp; sp = sp->se_next)
1862 sp->se_flags |= SE_SHUTDOWN;
1863
1864 return (state_func_t) multi_user;
1865 }
1866
1867 /*
1868 * Note SIGALRM.
1869 */
1870 static void
alrm_handler(int sig)1871 alrm_handler(int sig)
1872 {
1873
1874 (void)sig;
1875 clang = true;
1876 }
1877
1878 /*
1879 * Bring the system down to single user.
1880 */
1881 static state_func_t
death(void)1882 death(void)
1883 {
1884 int block, blocked;
1885 size_t len;
1886
1887 /* Temporarily block suspend. */
1888 len = sizeof(blocked);
1889 block = 1;
1890 if (sysctlbyname("kern.suspend_blocked", &blocked, &len,
1891 &block, sizeof(block)) == -1)
1892 blocked = 0;
1893
1894 /*
1895 * Also revoke the TTY here. Because runshutdown() may reopen
1896 * the TTY whose getty we're killing here, there is no guarantee
1897 * runshutdown() will perform the initial open() call, causing
1898 * the terminal attributes to be misconfigured.
1899 */
1900 revoke_ttys();
1901
1902 /* Try to run the rc.shutdown script within a period of time */
1903 runshutdown();
1904
1905 /* Unblock suspend if we blocked it. */
1906 if (!blocked)
1907 sysctlbyname("kern.suspend_blocked", NULL, NULL,
1908 &blocked, sizeof(blocked));
1909
1910 return (state_func_t) death_single;
1911 }
1912
1913 /*
1914 * Do what is necessary to reinitialize single user mode or reboot
1915 * from an incomplete state.
1916 */
1917 static state_func_t
death_single(void)1918 death_single(void)
1919 {
1920 int i;
1921 pid_t pid;
1922 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1923
1924 revoke(_PATH_CONSOLE);
1925
1926 BOOTTRACE("start killing user processes");
1927 for (i = 0; i < 2; ++i) {
1928 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1929 return (state_func_t) single_user;
1930
1931 clang = false;
1932 alarm(DEATH_WATCH);
1933 do
1934 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1935 collect_child(pid);
1936 while (!clang && errno != ECHILD);
1937
1938 if (errno == ECHILD)
1939 return (state_func_t) single_user;
1940 }
1941
1942 warning("some processes would not die; ps axl advised");
1943
1944 return (state_func_t) single_user;
1945 }
1946
1947 static void
revoke_ttys(void)1948 revoke_ttys(void)
1949 {
1950 session_t *sp;
1951
1952 for (sp = sessions; sp; sp = sp->se_next) {
1953 sp->se_flags |= SE_SHUTDOWN;
1954 kill(sp->se_process, SIGHUP);
1955 revoke(sp->se_device);
1956 }
1957 }
1958
1959 /*
1960 * Run the system shutdown script.
1961 *
1962 * Exit codes: XXX I should document more
1963 * -2 shutdown script terminated abnormally
1964 * -1 fatal error - can't run script
1965 * 0 good.
1966 * >0 some error (exit code)
1967 */
1968 static int
runshutdown(void)1969 runshutdown(void)
1970 {
1971 pid_t pid, wpid;
1972 int status;
1973 int shutdowntimeout;
1974 size_t len;
1975 char *argv[SCRIPT_ARGV_SIZE];
1976 struct stat sb;
1977
1978 BOOTTRACE("init(8): start rc.shutdown");
1979
1980 /*
1981 * rc.shutdown is optional, so to prevent any unnecessary
1982 * complaints from the shell we simply don't run it if the
1983 * file does not exist. If the stat() here fails for other
1984 * reasons, we'll let the shell complain.
1985 */
1986 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1987 return 0;
1988
1989 if ((pid = fork()) == 0) {
1990 char _reboot[] = "reboot";
1991 char _single[] = "single";
1992 char _path_rundown[] = _PATH_RUNDOWN;
1993
1994 argv[0] = _path_rundown;
1995 argv[1] = Reboot ? _reboot : _single;
1996 argv[2] = NULL;
1997
1998 execute_script(argv);
1999 _exit(1); /* force single user mode */
2000 }
2001
2002 if (pid == -1) {
2003 emergency("can't fork for %s: %m", _PATH_RUNDOWN);
2004 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
2005 continue;
2006 sleep(STALL_TIMEOUT);
2007 return -1;
2008 }
2009
2010 len = sizeof(shutdowntimeout);
2011 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
2012 NULL, 0) == -1 || shutdowntimeout < 2)
2013 shutdowntimeout = DEATH_SCRIPT;
2014 alarm(shutdowntimeout);
2015 clang = false;
2016 /*
2017 * Copied from single_user(). This is a bit paranoid.
2018 * Use the same ALRM handler.
2019 */
2020 do {
2021 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
2022 collect_child(wpid);
2023 if (clang) {
2024 /* we were waiting for the sub-shell */
2025 kill(wpid, SIGTERM);
2026 warning("timeout expired for %s: %m; going to "
2027 "single user mode", _PATH_RUNDOWN);
2028 BOOTTRACE("rc.shutdown's %d sec timeout expired",
2029 shutdowntimeout);
2030 return -1;
2031 }
2032 if (wpid == -1) {
2033 if (errno == EINTR)
2034 continue;
2035 warning("wait for %s failed: %m; going to "
2036 "single user mode", _PATH_RUNDOWN);
2037 return -1;
2038 }
2039 if (wpid == pid && WIFSTOPPED(status)) {
2040 warning("init: %s stopped, restarting\n",
2041 _PATH_RUNDOWN);
2042 kill(pid, SIGCONT);
2043 wpid = -1;
2044 }
2045 } while (wpid != pid && !clang);
2046
2047 /* Turn off the alarm */
2048 alarm(0);
2049
2050 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
2051 requested_transition == catatonia) {
2052 /*
2053 * /etc/rc.shutdown executed /sbin/reboot;
2054 * wait for the end quietly
2055 */
2056 sigset_t s;
2057
2058 sigfillset(&s);
2059 for (;;)
2060 sigsuspend(&s);
2061 }
2062
2063 if (!WIFEXITED(status)) {
2064 warning("%s terminated abnormally, going to "
2065 "single user mode", _PATH_RUNDOWN);
2066 return -2;
2067 }
2068
2069 if ((status = WEXITSTATUS(status)) != 0)
2070 warning("%s returned status %d", _PATH_RUNDOWN, status);
2071
2072 return status;
2073 }
2074
2075 static char *
strk(char * p)2076 strk(char *p)
2077 {
2078 static char *t;
2079 char *q;
2080 int c;
2081
2082 if (p)
2083 t = p;
2084 if (!t)
2085 return 0;
2086
2087 c = *t;
2088 while (c == ' ' || c == '\t' )
2089 c = *++t;
2090 if (!c) {
2091 t = 0;
2092 return 0;
2093 }
2094 q = t;
2095 if (c == '\'') {
2096 c = *++t;
2097 q = t;
2098 while (c && c != '\'')
2099 c = *++t;
2100 if (!c) /* unterminated string */
2101 q = t = 0;
2102 else
2103 *t++ = 0;
2104 } else {
2105 while (c && c != ' ' && c != '\t' )
2106 c = *++t;
2107 *t++ = 0;
2108 if (!c)
2109 t = 0;
2110 }
2111 return q;
2112 }
2113
2114 #ifdef LOGIN_CAP
2115 static void
setprocresources(const char * cname)2116 setprocresources(const char *cname)
2117 {
2118 login_cap_t *lc;
2119 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
2120 setusercontext(lc, (struct passwd*)NULL, 0,
2121 LOGIN_SETENV |
2122 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
2123 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
2124 login_close(lc);
2125 }
2126 }
2127 #endif
2128
2129 /*
2130 * Run /etc/rc.final to execute scripts after all user processes have been
2131 * terminated.
2132 */
2133 static void
runfinal(void)2134 runfinal(void)
2135 {
2136 struct stat sb;
2137 pid_t other_pid, pid;
2138 sigset_t mask;
2139
2140 /* Avoid any surprises. */
2141 alarm(0);
2142
2143 /* rc.final is optional. */
2144 if (stat(_PATH_RUNFINAL, &sb) == -1 && errno == ENOENT)
2145 return;
2146 if (access(_PATH_RUNFINAL, X_OK) != 0) {
2147 warning("%s exists, but not executable", _PATH_RUNFINAL);
2148 return;
2149 }
2150
2151 pid = fork();
2152 if (pid == 0) {
2153 /*
2154 * Reopen stdin/stdout/stderr so that scripts can write to
2155 * console.
2156 */
2157 close(0);
2158 open(_PATH_DEVNULL, O_RDONLY);
2159 close(1);
2160 close(2);
2161 open_console();
2162 dup2(1, 2);
2163 sigemptyset(&mask);
2164 sigprocmask(SIG_SETMASK, &mask, NULL);
2165 signal(SIGCHLD, SIG_DFL);
2166 execl(_PATH_RUNFINAL, _PATH_RUNFINAL, NULL);
2167 perror("execl(" _PATH_RUNFINAL ") failed");
2168 exit(1);
2169 }
2170
2171 /* Wait for rc.final script to exit */
2172 while ((other_pid = waitpid(-1, NULL, 0)) != pid && other_pid > 0) {
2173 continue;
2174 }
2175 }
2176