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 <paths.h>
53 #include <signal.h>
54 #include <stdarg.h>
55 #include <stdbool.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <syslog.h>
60 #include <time.h>
61 #include <ttyent.h>
62 #include <unistd.h>
63
64 #ifdef SECURE
65 #include <pwd.h>
66 #endif
67
68 #ifdef LOGIN_CAP
69 #include <login_cap.h>
70 #endif
71
72 #include "mntopts.h"
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 #ifdef SECURE
855 struct ttyent *typ;
856 struct passwd *pp;
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 #ifdef SECURE
889 /*
890 * Check the root password.
891 * We don't care if the console is 'on' by default;
892 * it's the only tty that can be 'off' and 'secure'.
893 */
894 typ = getttynam("console");
895 pp = getpwnam("root");
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 endpwent();
913 #endif /* SECURE */
914
915 #ifdef DEBUGSHELL
916 {
917 char *cp = altshell;
918 int num;
919
920 #define SHREQUEST "Enter full pathname of shell or RETURN for "
921 write_stderr(SHREQUEST);
922 write_stderr(shell);
923 write_stderr(": ");
924 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
925 num != 0 && *cp != '\n' && cp < &altshell[127])
926 cp++;
927 *cp = '\0';
928 if (altshell[0] != '\0')
929 shell = altshell;
930 }
931 #endif /* DEBUGSHELL */
932
933 /*
934 * Unblock signals.
935 * We catch all the interesting ones,
936 * and those are reset to SIG_DFL on exec.
937 */
938 sigemptyset(&mask);
939 sigprocmask(SIG_SETMASK, &mask, NULL);
940
941 /*
942 * Fire off a shell.
943 * If the default one doesn't work, try the Bourne shell.
944 */
945
946 char name[] = "-sh";
947
948 argv[0] = name;
949 argv[1] = NULL;
950 execv(shell, argv);
951 emergency("can't exec %s for single user: %m", shell);
952 execv(_PATH_BSHELL, argv);
953 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
954 sleep(STALL_TIMEOUT);
955 _exit(1);
956 }
957
958 if (pid == -1) {
959 /*
960 * We are seriously hosed. Do our best.
961 */
962 emergency("can't fork single-user shell, trying again");
963 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
964 continue;
965 return (state_func_t) single_user;
966 }
967
968 requested_transition = 0;
969 do {
970 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
971 collect_child(wpid);
972 if (wpid == -1) {
973 if (errno == EINTR)
974 continue;
975 warning("wait for single-user shell failed: %m; restarting");
976 return (state_func_t) single_user;
977 }
978 if (wpid == pid && WIFSTOPPED(status)) {
979 warning("init: shell stopped, restarting\n");
980 kill(pid, SIGCONT);
981 wpid = -1;
982 }
983 } while (wpid != pid && !requested_transition);
984
985 if (requested_transition)
986 return (state_func_t) requested_transition;
987
988 if (!WIFEXITED(status)) {
989 if (WTERMSIG(status) == SIGKILL) {
990 /*
991 * reboot(8) killed shell?
992 */
993 warning("single user shell terminated.");
994 gettimeofday(&tv, NULL);
995 tn = tv;
996 tv.tv_sec += STALL_TIMEOUT;
997 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec ==
998 tn.tv_sec && tv.tv_usec > tn.tv_usec)) {
999 sleep(1);
1000 gettimeofday(&tn, NULL);
1001 }
1002 _exit(0);
1003 } else {
1004 warning("single user shell terminated, restarting");
1005 return (state_func_t) single_user;
1006 }
1007 }
1008
1009 runcom_mode = FASTBOOT;
1010 return (state_func_t) runcom;
1011 }
1012
1013 /*
1014 * Run the system startup script.
1015 */
1016 static state_func_t
runcom(void)1017 runcom(void)
1018 {
1019 state_func_t next_transition;
1020
1021 BOOTTRACE("/etc/rc starting...");
1022 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL)
1023 return next_transition;
1024 BOOTTRACE("/etc/rc finished");
1025
1026 runcom_mode = AUTOBOOT; /* the default */
1027 return (state_func_t) read_ttys;
1028 }
1029
1030 static void
execute_script(char * argv[])1031 execute_script(char *argv[])
1032 {
1033 struct sigaction sa;
1034 char* sh_argv[3 + SCRIPT_ARGV_SIZE];
1035 const char *shell, *script;
1036 int error, sh_argv_len, i;
1037
1038 bzero(&sa, sizeof(sa));
1039 sigemptyset(&sa.sa_mask);
1040 sa.sa_handler = SIG_IGN;
1041 sigaction(SIGTSTP, &sa, NULL);
1042 sigaction(SIGHUP, &sa, NULL);
1043
1044 open_console();
1045
1046 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1047 #ifdef LOGIN_CAP
1048 setprocresources(RESOURCE_RC);
1049 #endif
1050
1051 /*
1052 * Try to directly execute the script first. If it
1053 * fails, try the old method of passing the script path
1054 * to sh(1). Don't complain if it fails because of
1055 * the missing execute bit.
1056 */
1057 script = argv[0];
1058 error = access(script, X_OK);
1059 if (error == 0) {
1060 execv(script, argv);
1061 warning("can't directly exec %s: %m", script);
1062 } else if (errno != EACCES) {
1063 warning("can't access %s: %m", script);
1064 }
1065
1066 shell = get_shell();
1067 sh_argv[0] = __DECONST(char*, shell);
1068 sh_argv_len = 1;
1069 #ifdef SECURE
1070 if (strcmp(shell, _PATH_BSHELL) == 0) {
1071 sh_argv[1] = __DECONST(char*, "-o");
1072 sh_argv[2] = __DECONST(char*, "verify");
1073 sh_argv_len = 3;
1074 }
1075 #endif
1076 for (i = 0; i != SCRIPT_ARGV_SIZE; ++i)
1077 sh_argv[i + sh_argv_len] = argv[i];
1078 execv(shell, sh_argv);
1079 stall("can't exec %s for %s: %m", shell, script);
1080 }
1081
1082 /*
1083 * Execute binary, replacing init(8) as PID 1.
1084 */
1085 static void
replace_init(char * path)1086 replace_init(char *path)
1087 {
1088 char *argv[SCRIPT_ARGV_SIZE];
1089
1090 argv[0] = path;
1091 argv[1] = NULL;
1092
1093 execute_script(argv);
1094 }
1095
1096 /*
1097 * Run a shell script.
1098 * Returns 0 on success, otherwise the next transition to enter:
1099 * - single_user if fork/execv/waitpid failed, or if the script
1100 * terminated with a signal or exit code != 0.
1101 * - death_single if a SIGTERM was delivered to init(8).
1102 */
1103 static state_func_t
run_script(const char * script)1104 run_script(const char *script)
1105 {
1106 pid_t pid, wpid;
1107 int status;
1108 char *argv[SCRIPT_ARGV_SIZE];
1109 const char *shell;
1110
1111 shell = get_shell();
1112
1113 if ((pid = fork()) == 0) {
1114
1115 char _autoboot[] = "autoboot";
1116
1117 argv[0] = __DECONST(char *, script);
1118 argv[1] = runcom_mode == AUTOBOOT ? _autoboot : NULL;
1119 argv[2] = NULL;
1120
1121 execute_script(argv);
1122 sleep(STALL_TIMEOUT);
1123 _exit(1); /* force single user mode */
1124 }
1125
1126 if (pid == -1) {
1127 emergency("can't fork for %s on %s: %m", shell, script);
1128 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1129 continue;
1130 sleep(STALL_TIMEOUT);
1131 return (state_func_t) single_user;
1132 }
1133
1134 /*
1135 * Copied from single_user(). This is a bit paranoid.
1136 */
1137 requested_transition = 0;
1138 do {
1139 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1140 collect_child(wpid);
1141 if (requested_transition == death_single ||
1142 requested_transition == reroot)
1143 return (state_func_t) requested_transition;
1144 if (wpid == -1) {
1145 if (errno == EINTR)
1146 continue;
1147 warning("wait for %s on %s failed: %m; going to "
1148 "single user mode", shell, script);
1149 return (state_func_t) single_user;
1150 }
1151 if (wpid == pid && WIFSTOPPED(status)) {
1152 warning("init: %s on %s stopped, restarting\n",
1153 shell, script);
1154 kill(pid, SIGCONT);
1155 wpid = -1;
1156 }
1157 } while (wpid != pid);
1158
1159 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1160 requested_transition == catatonia) {
1161 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
1162 sigset_t s;
1163
1164 sigfillset(&s);
1165 for (;;)
1166 sigsuspend(&s);
1167 }
1168
1169 if (!WIFEXITED(status)) {
1170 warning("%s on %s terminated abnormally, going to single "
1171 "user mode", shell, script);
1172 return (state_func_t) single_user;
1173 }
1174
1175 if (WEXITSTATUS(status))
1176 return (state_func_t) single_user;
1177
1178 return (state_func_t) 0;
1179 }
1180
1181 /*
1182 * Open the session database.
1183 *
1184 * NB: We could pass in the size here; is it necessary?
1185 */
1186 static int
start_session_db(void)1187 start_session_db(void)
1188 {
1189 if (session_db && (*session_db->close)(session_db))
1190 emergency("session database close: %m");
1191 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) {
1192 emergency("session database open: %m");
1193 return (1);
1194 }
1195 return (0);
1196
1197 }
1198
1199 /*
1200 * Add a new login session.
1201 */
1202 static void
add_session(session_t * sp)1203 add_session(session_t *sp)
1204 {
1205 DBT key;
1206 DBT data;
1207
1208 key.data = &sp->se_process;
1209 key.size = sizeof sp->se_process;
1210 data.data = &sp;
1211 data.size = sizeof sp;
1212
1213 if ((*session_db->put)(session_db, &key, &data, 0))
1214 emergency("insert %d: %m", sp->se_process);
1215 }
1216
1217 /*
1218 * Delete an old login session.
1219 */
1220 static void
del_session(session_t * sp)1221 del_session(session_t *sp)
1222 {
1223 DBT key;
1224
1225 key.data = &sp->se_process;
1226 key.size = sizeof sp->se_process;
1227
1228 if ((*session_db->del)(session_db, &key, 0))
1229 emergency("delete %d: %m", sp->se_process);
1230 }
1231
1232 /*
1233 * Look up a login session by pid.
1234 */
1235 static session_t *
find_session(pid_t pid)1236 find_session(pid_t pid)
1237 {
1238 DBT key;
1239 DBT data;
1240 session_t *ret;
1241
1242 key.data = &pid;
1243 key.size = sizeof pid;
1244 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
1245 return 0;
1246 bcopy(data.data, (char *)&ret, sizeof(ret));
1247 return ret;
1248 }
1249
1250 /*
1251 * Construct an argument vector from a command line.
1252 */
1253 static char **
construct_argv(char * command)1254 construct_argv(char *command)
1255 {
1256 int argc = 0;
1257 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
1258 * sizeof (char *));
1259
1260 if ((argv[argc++] = strk(command)) == NULL) {
1261 free(argv);
1262 return (NULL);
1263 }
1264 while ((argv[argc++] = strk((char *) 0)) != NULL)
1265 continue;
1266 return argv;
1267 }
1268
1269 /*
1270 * Deallocate a session descriptor.
1271 */
1272 static void
free_session(session_t * sp)1273 free_session(session_t *sp)
1274 {
1275 free(sp->se_device);
1276 if (sp->se_getty) {
1277 free(sp->se_getty);
1278 free(sp->se_getty_argv_space);
1279 free(sp->se_getty_argv);
1280 }
1281 if (sp->se_window) {
1282 free(sp->se_window);
1283 free(sp->se_window_argv_space);
1284 free(sp->se_window_argv);
1285 }
1286 if (sp->se_type)
1287 free(sp->se_type);
1288 free(sp);
1289 }
1290
1291 /*
1292 * Allocate a new session descriptor.
1293 * Mark it SE_PRESENT.
1294 */
1295 static session_t *
new_session(session_t * sprev,struct ttyent * typ)1296 new_session(session_t *sprev, struct ttyent *typ)
1297 {
1298 session_t *sp;
1299
1300 if ((typ->ty_status & TTY_ON) == 0 ||
1301 typ->ty_name == 0 ||
1302 typ->ty_getty == 0)
1303 return 0;
1304
1305 sp = (session_t *) calloc(1, sizeof (session_t));
1306
1307 sp->se_flags |= SE_PRESENT;
1308
1309 if ((typ->ty_status & TTY_IFEXISTS) != 0)
1310 sp->se_flags |= SE_IFEXISTS;
1311
1312 if ((typ->ty_status & TTY_IFCONSOLE) != 0)
1313 sp->se_flags |= SE_IFCONSOLE;
1314
1315 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0)
1316 err(1, "asprintf");
1317
1318 if (setupargv(sp, typ) == 0) {
1319 free_session(sp);
1320 return (0);
1321 }
1322
1323 sp->se_next = 0;
1324 if (sprev == NULL) {
1325 sessions = sp;
1326 sp->se_prev = 0;
1327 } else {
1328 sprev->se_next = sp;
1329 sp->se_prev = sprev;
1330 }
1331
1332 return sp;
1333 }
1334
1335 /*
1336 * Calculate getty and if useful window argv vectors.
1337 */
1338 static int
setupargv(session_t * sp,struct ttyent * typ)1339 setupargv(session_t *sp, struct ttyent *typ)
1340 {
1341
1342 if (sp->se_getty) {
1343 free(sp->se_getty);
1344 free(sp->se_getty_argv_space);
1345 free(sp->se_getty_argv);
1346 }
1347 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0)
1348 err(1, "asprintf");
1349 sp->se_getty_argv_space = strdup(sp->se_getty);
1350 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1351 if (sp->se_getty_argv == NULL) {
1352 warning("can't parse getty for port %s", sp->se_device);
1353 free(sp->se_getty);
1354 free(sp->se_getty_argv_space);
1355 sp->se_getty = sp->se_getty_argv_space = 0;
1356 return (0);
1357 }
1358 if (sp->se_window) {
1359 free(sp->se_window);
1360 free(sp->se_window_argv_space);
1361 free(sp->se_window_argv);
1362 }
1363 sp->se_window = sp->se_window_argv_space = 0;
1364 sp->se_window_argv = 0;
1365 if (typ->ty_window) {
1366 sp->se_window = strdup(typ->ty_window);
1367 sp->se_window_argv_space = strdup(sp->se_window);
1368 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1369 if (sp->se_window_argv == NULL) {
1370 warning("can't parse window for port %s",
1371 sp->se_device);
1372 free(sp->se_window_argv_space);
1373 free(sp->se_window);
1374 sp->se_window = sp->se_window_argv_space = 0;
1375 return (0);
1376 }
1377 }
1378 if (sp->se_type)
1379 free(sp->se_type);
1380 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1381 return (1);
1382 }
1383
1384 /*
1385 * Walk the list of ttys and create sessions for each active line.
1386 */
1387 static state_func_t
read_ttys(void)1388 read_ttys(void)
1389 {
1390 session_t *sp, *snext;
1391 struct ttyent *typ;
1392
1393 /*
1394 * Destroy any previous session state.
1395 * There shouldn't be any, but just in case...
1396 */
1397 for (sp = sessions; sp; sp = snext) {
1398 snext = sp->se_next;
1399 free_session(sp);
1400 }
1401 sessions = 0;
1402 if (start_session_db())
1403 return (state_func_t) single_user;
1404
1405 /*
1406 * Allocate a session entry for each active port.
1407 * Note that sp starts at 0.
1408 */
1409 while ((typ = getttyent()) != NULL)
1410 if ((snext = new_session(sp, typ)) != NULL)
1411 sp = snext;
1412
1413 endttyent();
1414
1415 return (state_func_t) multi_user;
1416 }
1417
1418 /*
1419 * Start a window system running.
1420 */
1421 static void
start_window_system(session_t * sp)1422 start_window_system(session_t *sp)
1423 {
1424 pid_t pid;
1425 sigset_t mask;
1426 char term[64], *env[2];
1427 int status;
1428
1429 if ((pid = fork()) == -1) {
1430 emergency("can't fork for window system on port %s: %m",
1431 sp->se_device);
1432 /* hope that getty fails and we can try again */
1433 return;
1434 }
1435 if (pid) {
1436 waitpid(-1, &status, 0);
1437 return;
1438 }
1439
1440 /* reparent window process to the init to not make a zombie on exit */
1441 if ((pid = fork()) == -1) {
1442 emergency("can't fork for window system on port %s: %m",
1443 sp->se_device);
1444 _exit(1);
1445 }
1446 if (pid)
1447 _exit(0);
1448
1449 sigemptyset(&mask);
1450 sigprocmask(SIG_SETMASK, &mask, NULL);
1451
1452 if (setsid() < 0)
1453 emergency("setsid failed (window) %m");
1454
1455 #ifdef LOGIN_CAP
1456 setprocresources(RESOURCE_WINDOW);
1457 #endif
1458 if (sp->se_type) {
1459 /* Don't use malloc after fork */
1460 strcpy(term, "TERM=");
1461 strlcat(term, sp->se_type, sizeof(term));
1462 env[0] = term;
1463 env[1] = NULL;
1464 }
1465 else
1466 env[0] = NULL;
1467 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1468 stall("can't exec window system '%s' for port %s: %m",
1469 sp->se_window_argv[0], sp->se_device);
1470 _exit(1);
1471 }
1472
1473 /*
1474 * Start a login session running.
1475 */
1476 static pid_t
start_getty(session_t * sp)1477 start_getty(session_t *sp)
1478 {
1479 pid_t pid;
1480 sigset_t mask;
1481 time_t current_time = time((time_t *) 0);
1482 int too_quick = 0;
1483 char term[64], *env[2];
1484
1485 if (current_time >= sp->se_started &&
1486 current_time - sp->se_started < GETTY_SPACING) {
1487 if (++sp->se_nspace > GETTY_NSPACE) {
1488 sp->se_nspace = 0;
1489 too_quick = 1;
1490 }
1491 } else
1492 sp->se_nspace = 0;
1493
1494 /*
1495 * fork(), not vfork() -- we can't afford to block.
1496 */
1497 if ((pid = fork()) == -1) {
1498 emergency("can't fork for getty on port %s: %m", sp->se_device);
1499 return -1;
1500 }
1501
1502 if (pid)
1503 return pid;
1504
1505 if (too_quick) {
1506 warning("getty repeating too quickly on port %s, sleeping %d secs",
1507 sp->se_device, GETTY_SLEEP);
1508 sleep((unsigned) GETTY_SLEEP);
1509 }
1510
1511 if (sp->se_window) {
1512 start_window_system(sp);
1513 sleep(WINDOW_WAIT);
1514 }
1515
1516 sigemptyset(&mask);
1517 sigprocmask(SIG_SETMASK, &mask, NULL);
1518
1519 #ifdef LOGIN_CAP
1520 setprocresources(RESOURCE_GETTY);
1521 #endif
1522 if (sp->se_type) {
1523 /* Don't use malloc after fork */
1524 strcpy(term, "TERM=");
1525 strlcat(term, sp->se_type, sizeof(term));
1526 env[0] = term;
1527 env[1] = NULL;
1528 } else
1529 env[0] = NULL;
1530 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1531 stall("can't exec getty '%s' for port %s: %m",
1532 sp->se_getty_argv[0], sp->se_device);
1533 _exit(1);
1534 }
1535
1536 /*
1537 * Return 1 if the session is defined as "onifexists"
1538 * or "onifconsole" and the device node does not exist.
1539 */
1540 static int
session_has_no_tty(session_t * sp)1541 session_has_no_tty(session_t *sp)
1542 {
1543 int fd;
1544
1545 if ((sp->se_flags & SE_IFEXISTS) == 0 &&
1546 (sp->se_flags & SE_IFCONSOLE) == 0)
1547 return (0);
1548
1549 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0);
1550 if (fd < 0) {
1551 if (errno == ENOENT)
1552 return (1);
1553 return (0);
1554 }
1555
1556 close(fd);
1557 return (0);
1558 }
1559
1560 /*
1561 * Collect exit status for a child.
1562 * If an exiting login, start a new login running.
1563 */
1564 static void
collect_child(pid_t pid)1565 collect_child(pid_t pid)
1566 {
1567 session_t *sp, *sprev, *snext;
1568
1569 if (! sessions)
1570 return;
1571
1572 if (! (sp = find_session(pid)))
1573 return;
1574
1575 del_session(sp);
1576 sp->se_process = 0;
1577
1578 if (sp->se_flags & SE_SHUTDOWN ||
1579 session_has_no_tty(sp)) {
1580 if ((sprev = sp->se_prev) != NULL)
1581 sprev->se_next = sp->se_next;
1582 else
1583 sessions = sp->se_next;
1584 if ((snext = sp->se_next) != NULL)
1585 snext->se_prev = sp->se_prev;
1586 free_session(sp);
1587 return;
1588 }
1589
1590 if ((pid = start_getty(sp)) == -1) {
1591 /* serious trouble */
1592 requested_transition = clean_ttys;
1593 return;
1594 }
1595
1596 sp->se_process = pid;
1597 sp->se_started = time((time_t *) 0);
1598 add_session(sp);
1599 }
1600
1601 static const char *
get_current_state(void)1602 get_current_state(void)
1603 {
1604
1605 if (current_state == single_user)
1606 return ("single-user");
1607 if (current_state == runcom)
1608 return ("runcom");
1609 if (current_state == read_ttys)
1610 return ("read-ttys");
1611 if (current_state == multi_user)
1612 return ("multi-user");
1613 if (current_state == clean_ttys)
1614 return ("clean-ttys");
1615 if (current_state == catatonia)
1616 return ("catatonia");
1617 if (current_state == death)
1618 return ("death");
1619 if (current_state == death_single)
1620 return ("death-single");
1621 return ("unknown");
1622 }
1623
1624 static void
boottrace_transition(int sig)1625 boottrace_transition(int sig)
1626 {
1627 const char *action;
1628
1629 switch (sig) {
1630 case SIGUSR2:
1631 action = "halt & poweroff";
1632 break;
1633 case SIGUSR1:
1634 action = "halt";
1635 break;
1636 case SIGINT:
1637 action = "reboot";
1638 break;
1639 case SIGWINCH:
1640 action = "powercycle";
1641 break;
1642 case SIGTERM:
1643 action = Reboot ? "reboot" : "single-user";
1644 break;
1645 default:
1646 BOOTTRACE("signal %d from %s", sig, get_current_state());
1647 return;
1648 }
1649
1650 /* Trace the shutdown reason. */
1651 SHUTTRACE("%s from %s", action, get_current_state());
1652 }
1653
1654 /*
1655 * Catch a signal and request a state transition.
1656 */
1657 static void
transition_handler(int sig)1658 transition_handler(int sig)
1659 {
1660
1661 boottrace_transition(sig);
1662 switch (sig) {
1663 case SIGHUP:
1664 if (current_state == read_ttys || current_state == multi_user ||
1665 current_state == clean_ttys || current_state == catatonia)
1666 requested_transition = clean_ttys;
1667 break;
1668 case SIGUSR2:
1669 howto = RB_POWEROFF;
1670 case SIGUSR1:
1671 howto |= RB_HALT;
1672 case SIGWINCH:
1673 case SIGINT:
1674 if (sig == SIGWINCH)
1675 howto |= RB_POWERCYCLE;
1676 Reboot = true;
1677 case SIGTERM:
1678 if (current_state == read_ttys || current_state == multi_user ||
1679 current_state == clean_ttys || current_state == catatonia)
1680 requested_transition = death;
1681 else
1682 requested_transition = death_single;
1683 break;
1684 case SIGTSTP:
1685 if (current_state == runcom || current_state == read_ttys ||
1686 current_state == clean_ttys ||
1687 current_state == multi_user || current_state == catatonia)
1688 requested_transition = catatonia;
1689 break;
1690 case SIGEMT:
1691 requested_transition = reroot;
1692 break;
1693 default:
1694 requested_transition = 0;
1695 break;
1696 }
1697 }
1698
1699 /*
1700 * Take the system multiuser.
1701 */
1702 static state_func_t
multi_user(void)1703 multi_user(void)
1704 {
1705 static bool inmultiuser = false;
1706 pid_t pid;
1707 session_t *sp;
1708
1709 requested_transition = 0;
1710
1711 /*
1712 * If the administrator has not set the security level to -1
1713 * to indicate that the kernel should not run multiuser in secure
1714 * mode, and the run script has not set a higher level of security
1715 * than level 1, then put the kernel into secure mode.
1716 */
1717 if (getsecuritylevel() == 0)
1718 setsecuritylevel(1);
1719
1720 for (sp = sessions; sp; sp = sp->se_next) {
1721 if (sp->se_process)
1722 continue;
1723 if (session_has_no_tty(sp))
1724 continue;
1725 if ((pid = start_getty(sp)) == -1) {
1726 /* serious trouble */
1727 requested_transition = clean_ttys;
1728 break;
1729 }
1730 sp->se_process = pid;
1731 sp->se_started = time((time_t *) 0);
1732 add_session(sp);
1733 }
1734
1735 if (requested_transition == 0 && !inmultiuser) {
1736 inmultiuser = true;
1737 /* This marks the change from boot-time tracing to run-time. */
1738 RUNTRACE("multi-user start");
1739 }
1740 while (!requested_transition)
1741 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1742 collect_child(pid);
1743
1744 return (state_func_t) requested_transition;
1745 }
1746
1747 /*
1748 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1749 */
1750 static state_func_t
clean_ttys(void)1751 clean_ttys(void)
1752 {
1753 session_t *sp, *sprev;
1754 struct ttyent *typ;
1755 int devlen;
1756 char *old_getty, *old_window, *old_type;
1757
1758 /*
1759 * mark all sessions for death, (!SE_PRESENT)
1760 * as we find or create new ones they'll be marked as keepers,
1761 * we'll later nuke all the ones not found in /etc/ttys
1762 */
1763 for (sp = sessions; sp != NULL; sp = sp->se_next)
1764 sp->se_flags &= ~SE_PRESENT;
1765
1766 devlen = sizeof(_PATH_DEV) - 1;
1767 while ((typ = getttyent()) != NULL) {
1768 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1769 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1770 break;
1771
1772 if (sp) {
1773 /* we want this one to live */
1774 sp->se_flags |= SE_PRESENT;
1775 if ((typ->ty_status & TTY_ON) == 0 ||
1776 typ->ty_getty == 0) {
1777 sp->se_flags |= SE_SHUTDOWN;
1778 kill(sp->se_process, SIGHUP);
1779 continue;
1780 }
1781 sp->se_flags &= ~SE_SHUTDOWN;
1782 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1783 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1784 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1785 if (setupargv(sp, typ) == 0) {
1786 warning("can't parse getty for port %s",
1787 sp->se_device);
1788 sp->se_flags |= SE_SHUTDOWN;
1789 kill(sp->se_process, SIGHUP);
1790 }
1791 else if ( !old_getty
1792 || (!old_type && sp->se_type)
1793 || (old_type && !sp->se_type)
1794 || (!old_window && sp->se_window)
1795 || (old_window && !sp->se_window)
1796 || (strcmp(old_getty, sp->se_getty) != 0)
1797 || (old_window && strcmp(old_window, sp->se_window) != 0)
1798 || (old_type && strcmp(old_type, sp->se_type) != 0)
1799 ) {
1800 /* Don't set SE_SHUTDOWN here */
1801 sp->se_nspace = 0;
1802 sp->se_started = 0;
1803 kill(sp->se_process, SIGHUP);
1804 }
1805 if (old_getty)
1806 free(old_getty);
1807 if (old_window)
1808 free(old_window);
1809 if (old_type)
1810 free(old_type);
1811 continue;
1812 }
1813
1814 new_session(sprev, typ);
1815 }
1816
1817 endttyent();
1818
1819 /*
1820 * sweep through and kill all deleted sessions
1821 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1822 */
1823 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1824 if ((sp->se_flags & SE_PRESENT) == 0) {
1825 sp->se_flags |= SE_SHUTDOWN;
1826 kill(sp->se_process, SIGHUP);
1827 }
1828 }
1829
1830 return (state_func_t) multi_user;
1831 }
1832
1833 /*
1834 * Block further logins.
1835 */
1836 static state_func_t
catatonia(void)1837 catatonia(void)
1838 {
1839 session_t *sp;
1840
1841 for (sp = sessions; sp; sp = sp->se_next)
1842 sp->se_flags |= SE_SHUTDOWN;
1843
1844 return (state_func_t) multi_user;
1845 }
1846
1847 /*
1848 * Note SIGALRM.
1849 */
1850 static void
alrm_handler(int sig)1851 alrm_handler(int sig)
1852 {
1853
1854 (void)sig;
1855 clang = true;
1856 }
1857
1858 /*
1859 * Bring the system down to single user.
1860 */
1861 static state_func_t
death(void)1862 death(void)
1863 {
1864 int block, blocked;
1865 size_t len;
1866
1867 /* Temporarily block suspend. */
1868 len = sizeof(blocked);
1869 block = 1;
1870 if (sysctlbyname("kern.suspend_blocked", &blocked, &len,
1871 &block, sizeof(block)) == -1)
1872 blocked = 0;
1873
1874 /*
1875 * Also revoke the TTY here. Because runshutdown() may reopen
1876 * the TTY whose getty we're killing here, there is no guarantee
1877 * runshutdown() will perform the initial open() call, causing
1878 * the terminal attributes to be misconfigured.
1879 */
1880 revoke_ttys();
1881
1882 /* Try to run the rc.shutdown script within a period of time */
1883 runshutdown();
1884
1885 /* Unblock suspend if we blocked it. */
1886 if (!blocked)
1887 sysctlbyname("kern.suspend_blocked", NULL, NULL,
1888 &blocked, sizeof(blocked));
1889
1890 return (state_func_t) death_single;
1891 }
1892
1893 /*
1894 * Do what is necessary to reinitialize single user mode or reboot
1895 * from an incomplete state.
1896 */
1897 static state_func_t
death_single(void)1898 death_single(void)
1899 {
1900 int i;
1901 pid_t pid;
1902 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1903
1904 revoke(_PATH_CONSOLE);
1905
1906 BOOTTRACE("start killing user processes");
1907 for (i = 0; i < 2; ++i) {
1908 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1909 return (state_func_t) single_user;
1910
1911 clang = false;
1912 alarm(DEATH_WATCH);
1913 do
1914 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1915 collect_child(pid);
1916 while (!clang && errno != ECHILD);
1917
1918 if (errno == ECHILD)
1919 return (state_func_t) single_user;
1920 }
1921
1922 warning("some processes would not die; ps axl advised");
1923
1924 return (state_func_t) single_user;
1925 }
1926
1927 static void
revoke_ttys(void)1928 revoke_ttys(void)
1929 {
1930 session_t *sp;
1931
1932 for (sp = sessions; sp; sp = sp->se_next) {
1933 sp->se_flags |= SE_SHUTDOWN;
1934 kill(sp->se_process, SIGHUP);
1935 revoke(sp->se_device);
1936 }
1937 }
1938
1939 /*
1940 * Run the system shutdown script.
1941 *
1942 * Exit codes: XXX I should document more
1943 * -2 shutdown script terminated abnormally
1944 * -1 fatal error - can't run script
1945 * 0 good.
1946 * >0 some error (exit code)
1947 */
1948 static int
runshutdown(void)1949 runshutdown(void)
1950 {
1951 pid_t pid, wpid;
1952 int status;
1953 int shutdowntimeout;
1954 size_t len;
1955 char *argv[SCRIPT_ARGV_SIZE];
1956 struct stat sb;
1957
1958 BOOTTRACE("init(8): start rc.shutdown");
1959
1960 /*
1961 * rc.shutdown is optional, so to prevent any unnecessary
1962 * complaints from the shell we simply don't run it if the
1963 * file does not exist. If the stat() here fails for other
1964 * reasons, we'll let the shell complain.
1965 */
1966 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1967 return 0;
1968
1969 if ((pid = fork()) == 0) {
1970 char _reboot[] = "reboot";
1971 char _single[] = "single";
1972 char _path_rundown[] = _PATH_RUNDOWN;
1973
1974 argv[0] = _path_rundown;
1975 argv[1] = Reboot ? _reboot : _single;
1976 argv[2] = NULL;
1977
1978 execute_script(argv);
1979 _exit(1); /* force single user mode */
1980 }
1981
1982 if (pid == -1) {
1983 emergency("can't fork for %s: %m", _PATH_RUNDOWN);
1984 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1985 continue;
1986 sleep(STALL_TIMEOUT);
1987 return -1;
1988 }
1989
1990 len = sizeof(shutdowntimeout);
1991 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
1992 NULL, 0) == -1 || shutdowntimeout < 2)
1993 shutdowntimeout = DEATH_SCRIPT;
1994 alarm(shutdowntimeout);
1995 clang = false;
1996 /*
1997 * Copied from single_user(). This is a bit paranoid.
1998 * Use the same ALRM handler.
1999 */
2000 do {
2001 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
2002 collect_child(wpid);
2003 if (clang) {
2004 /* we were waiting for the sub-shell */
2005 kill(wpid, SIGTERM);
2006 warning("timeout expired for %s: %m; going to "
2007 "single user mode", _PATH_RUNDOWN);
2008 BOOTTRACE("rc.shutdown's %d sec timeout expired",
2009 shutdowntimeout);
2010 return -1;
2011 }
2012 if (wpid == -1) {
2013 if (errno == EINTR)
2014 continue;
2015 warning("wait for %s failed: %m; going to "
2016 "single user mode", _PATH_RUNDOWN);
2017 return -1;
2018 }
2019 if (wpid == pid && WIFSTOPPED(status)) {
2020 warning("init: %s stopped, restarting\n",
2021 _PATH_RUNDOWN);
2022 kill(pid, SIGCONT);
2023 wpid = -1;
2024 }
2025 } while (wpid != pid && !clang);
2026
2027 /* Turn off the alarm */
2028 alarm(0);
2029
2030 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
2031 requested_transition == catatonia) {
2032 /*
2033 * /etc/rc.shutdown executed /sbin/reboot;
2034 * wait for the end quietly
2035 */
2036 sigset_t s;
2037
2038 sigfillset(&s);
2039 for (;;)
2040 sigsuspend(&s);
2041 }
2042
2043 if (!WIFEXITED(status)) {
2044 warning("%s terminated abnormally, going to "
2045 "single user mode", _PATH_RUNDOWN);
2046 return -2;
2047 }
2048
2049 if ((status = WEXITSTATUS(status)) != 0)
2050 warning("%s returned status %d", _PATH_RUNDOWN, status);
2051
2052 return status;
2053 }
2054
2055 static char *
strk(char * p)2056 strk(char *p)
2057 {
2058 static char *t;
2059 char *q;
2060 int c;
2061
2062 if (p)
2063 t = p;
2064 if (!t)
2065 return 0;
2066
2067 c = *t;
2068 while (c == ' ' || c == '\t' )
2069 c = *++t;
2070 if (!c) {
2071 t = 0;
2072 return 0;
2073 }
2074 q = t;
2075 if (c == '\'') {
2076 c = *++t;
2077 q = t;
2078 while (c && c != '\'')
2079 c = *++t;
2080 if (!c) /* unterminated string */
2081 q = t = 0;
2082 else
2083 *t++ = 0;
2084 } else {
2085 while (c && c != ' ' && c != '\t' )
2086 c = *++t;
2087 *t++ = 0;
2088 if (!c)
2089 t = 0;
2090 }
2091 return q;
2092 }
2093
2094 #ifdef LOGIN_CAP
2095 static void
setprocresources(const char * cname)2096 setprocresources(const char *cname)
2097 {
2098 login_cap_t *lc;
2099 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
2100 setusercontext(lc, (struct passwd*)NULL, 0,
2101 LOGIN_SETENV |
2102 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
2103 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
2104 login_close(lc);
2105 }
2106 }
2107 #endif
2108
2109 /*
2110 * Run /etc/rc.final to execute scripts after all user processes have been
2111 * terminated.
2112 */
2113 static void
runfinal(void)2114 runfinal(void)
2115 {
2116 struct stat sb;
2117 pid_t other_pid, pid;
2118 sigset_t mask;
2119
2120 /* Avoid any surprises. */
2121 alarm(0);
2122
2123 /* rc.final is optional. */
2124 if (stat(_PATH_RUNFINAL, &sb) == -1 && errno == ENOENT)
2125 return;
2126 if (access(_PATH_RUNFINAL, X_OK) != 0) {
2127 warning("%s exists, but not executable", _PATH_RUNFINAL);
2128 return;
2129 }
2130
2131 pid = fork();
2132 if (pid == 0) {
2133 /*
2134 * Reopen stdin/stdout/stderr so that scripts can write to
2135 * console.
2136 */
2137 close(0);
2138 open(_PATH_DEVNULL, O_RDONLY);
2139 close(1);
2140 close(2);
2141 open_console();
2142 dup2(1, 2);
2143 sigemptyset(&mask);
2144 sigprocmask(SIG_SETMASK, &mask, NULL);
2145 signal(SIGCHLD, SIG_DFL);
2146 execl(_PATH_RUNFINAL, _PATH_RUNFINAL, NULL);
2147 perror("execl(" _PATH_RUNFINAL ") failed");
2148 exit(1);
2149 }
2150
2151 /* Wait for rc.final script to exit */
2152 while ((other_pid = waitpid(-1, NULL, 0)) != pid && other_pid > 0) {
2153 continue;
2154 }
2155 }
2156