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 #ifndef lint
36 static const char copyright[] =
37 "@(#) Copyright (c) 1991, 1993\n\
38 The Regents of the University of California. All rights reserved.\n";
39 #endif /* not lint */
40
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93";
44 #endif
45 #endif /* not lint */
46
47 #include <sys/param.h>
48 #include <sys/ioctl.h>
49 #include <sys/mman.h>
50 #include <sys/mount.h>
51 #include <sys/sysctl.h>
52 #include <sys/wait.h>
53 #include <sys/stat.h>
54 #include <sys/uio.h>
55
56 #include <db.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <kenv.h>
60 #include <libutil.h>
61 #include <paths.h>
62 #include <signal.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <syslog.h>
67 #include <time.h>
68 #include <ttyent.h>
69 #include <unistd.h>
70 #include <sys/reboot.h>
71 #include <err.h>
72
73 #include <stdarg.h>
74
75 #ifdef SECURE
76 #include <pwd.h>
77 #endif
78
79 #ifdef LOGIN_CAP
80 #include <login_cap.h>
81 #endif
82
83 #include "mntopts.h"
84 #include "pathnames.h"
85
86 /*
87 * Sleep times; used to prevent thrashing.
88 */
89 #define GETTY_SPACING 5 /* N secs minimum getty spacing */
90 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */
91 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */
92 #define WINDOW_WAIT 3 /* wait N secs after starting window */
93 #define STALL_TIMEOUT 30 /* wait N secs after warning */
94 #define DEATH_WATCH 10 /* wait N secs for procs to die */
95 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */
96 #define RESOURCE_RC "daemon"
97 #define RESOURCE_WINDOW "default"
98 #define RESOURCE_GETTY "default"
99
100 static void handle(sig_t, ...);
101 static void delset(sigset_t *, ...);
102
103 static void stall(const char *, ...) __printflike(1, 2);
104 static void warning(const char *, ...) __printflike(1, 2);
105 static void emergency(const char *, ...) __printflike(1, 2);
106 static void disaster(int);
107 static void revoke_ttys(void);
108 static int runshutdown(void);
109 static char *strk(char *);
110 static void runfinal(void);
111
112 /*
113 * We really need a recursive typedef...
114 * The following at least guarantees that the return type of (*state_t)()
115 * is sufficiently wide to hold a function pointer.
116 */
117 typedef long (*state_func_t)(void);
118 typedef state_func_t (*state_t)(void);
119
120 static state_func_t single_user(void);
121 static state_func_t runcom(void);
122 static state_func_t read_ttys(void);
123 static state_func_t multi_user(void);
124 static state_func_t clean_ttys(void);
125 static state_func_t catatonia(void);
126 static state_func_t death(void);
127 static state_func_t death_single(void);
128 static state_func_t reroot(void);
129 static state_func_t reroot_phase_two(void);
130
131 static state_func_t run_script(const char *);
132
133 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
134 #define FALSE 0
135 #define TRUE 1
136
137 static int Reboot = FALSE;
138 static int howto = RB_AUTOBOOT;
139
140 static int devfs;
141 static char *init_path_argv0;
142
143 static void transition(state_t);
144 static state_t requested_transition;
145 static state_t current_state = death_single;
146
147 static void execute_script(char *argv[]);
148 static void open_console(void);
149 static const char *get_shell(void);
150 static void replace_init(char *path);
151 static void write_stderr(const char *message);
152
153 typedef struct init_session {
154 pid_t se_process; /* controlling process */
155 time_t se_started; /* used to avoid thrashing */
156 int se_flags; /* status of session */
157 #define SE_SHUTDOWN 0x1 /* session won't be restarted */
158 #define SE_PRESENT 0x2 /* session is in /etc/ttys */
159 #define SE_IFEXISTS 0x4 /* session defined as "onifexists" */
160 #define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */
161 int se_nspace; /* spacing count */
162 char *se_device; /* filename of port */
163 char *se_getty; /* what to run on that port */
164 char *se_getty_argv_space; /* pre-parsed argument array space */
165 char **se_getty_argv; /* pre-parsed argument array */
166 char *se_window; /* window system (started only once) */
167 char *se_window_argv_space; /* pre-parsed argument array space */
168 char **se_window_argv; /* pre-parsed argument array */
169 char *se_type; /* default terminal type */
170 struct init_session *se_prev;
171 struct init_session *se_next;
172 } session_t;
173
174 static void free_session(session_t *);
175 static session_t *new_session(session_t *, struct ttyent *);
176 static session_t *sessions;
177
178 static char **construct_argv(char *);
179 static void start_window_system(session_t *);
180 static void collect_child(pid_t);
181 static pid_t start_getty(session_t *);
182 static void transition_handler(int);
183 static void alrm_handler(int);
184 static void setsecuritylevel(int);
185 static int getsecuritylevel(void);
186 static int setupargv(session_t *, struct ttyent *);
187 #ifdef LOGIN_CAP
188 static void setprocresources(const char *);
189 #endif
190 static int clang;
191
192 static int start_session_db(void);
193 static void add_session(session_t *);
194 static void del_session(session_t *);
195 static session_t *find_session(pid_t);
196 static DB *session_db;
197
198 /*
199 * The mother of all processes.
200 */
201 int
main(int argc,char * argv[])202 main(int argc, char *argv[])
203 {
204 state_t initial_transition = runcom;
205 char kenv_value[PATH_MAX];
206 int c, error;
207 struct sigaction sa;
208 sigset_t mask;
209
210 /* Dispose of random users. */
211 if (getuid() != 0)
212 errx(1, "%s", strerror(EPERM));
213
214 /* System V users like to reexec init. */
215 if (getpid() != 1) {
216 #ifdef COMPAT_SYSV_INIT
217 /* So give them what they want */
218 if (argc > 1) {
219 if (strlen(argv[1]) == 1) {
220 char runlevel = *argv[1];
221 int sig;
222
223 switch (runlevel) {
224 case '0': /* halt + poweroff */
225 sig = SIGUSR2;
226 break;
227 case '1': /* single-user */
228 sig = SIGTERM;
229 break;
230 case '6': /* reboot */
231 sig = SIGINT;
232 break;
233 case 'c': /* block further logins */
234 sig = SIGTSTP;
235 break;
236 case 'q': /* rescan /etc/ttys */
237 sig = SIGHUP;
238 break;
239 case 'r': /* remount root */
240 sig = SIGEMT;
241 break;
242 default:
243 goto invalid;
244 }
245 kill(1, sig);
246 _exit(0);
247 } else
248 invalid:
249 errx(1, "invalid run-level ``%s''", argv[1]);
250 } else
251 #endif
252 errx(1, "already running");
253 }
254
255 init_path_argv0 = strdup(argv[0]);
256 if (init_path_argv0 == NULL)
257 err(1, "strdup");
258
259 /*
260 * Note that this does NOT open a file...
261 * Does 'init' deserve its own facility number?
262 */
263 openlog("init", LOG_CONS, LOG_AUTH);
264
265 /*
266 * Create an initial session.
267 */
268 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1))
269 warning("initial setsid() failed: %m");
270
271 /*
272 * Establish an initial user so that programs running
273 * single user do not freak out and die (like passwd).
274 */
275 if (setlogin("root") < 0)
276 warning("setlogin() failed: %m");
277
278 /*
279 * This code assumes that we always get arguments through flags,
280 * never through bits set in some random machine register.
281 */
282 while ((c = getopt(argc, argv, "dsfr")) != -1)
283 switch (c) {
284 case 'd':
285 devfs = 1;
286 break;
287 case 's':
288 initial_transition = single_user;
289 break;
290 case 'f':
291 runcom_mode = FASTBOOT;
292 break;
293 case 'r':
294 initial_transition = reroot_phase_two;
295 break;
296 default:
297 warning("unrecognized flag '-%c'", c);
298 break;
299 }
300
301 if (optind != argc)
302 warning("ignoring excess arguments");
303
304 /*
305 * We catch or block signals rather than ignore them,
306 * so that they get reset on exec.
307 */
308 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
309 SIGXCPU, SIGXFSZ, 0);
310 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
311 SIGUSR1, SIGUSR2, SIGWINCH, 0);
312 handle(alrm_handler, SIGALRM, 0);
313 sigfillset(&mask);
314 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
315 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
316 SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0);
317 sigprocmask(SIG_SETMASK, &mask, NULL);
318 sigemptyset(&sa.sa_mask);
319 sa.sa_flags = 0;
320 sa.sa_handler = SIG_IGN;
321 sigaction(SIGTTIN, &sa, NULL);
322 sigaction(SIGTTOU, &sa, NULL);
323
324 /*
325 * Paranoia.
326 */
327 close(0);
328 close(1);
329 close(2);
330
331 if (kenv(KENV_GET, "init_exec", kenv_value, sizeof(kenv_value)) > 0) {
332 replace_init(kenv_value);
333 _exit(0); /* reboot */
334 }
335
336 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
337 state_func_t next_transition;
338
339 if ((next_transition = run_script(kenv_value)) != NULL)
340 initial_transition = (state_t) next_transition;
341 }
342
343 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
344 if (chdir(kenv_value) != 0 || chroot(".") != 0)
345 warning("Can't chroot to %s: %m", kenv_value);
346 }
347
348 /*
349 * Additional check if devfs needs to be mounted:
350 * If "/" and "/dev" have the same device number,
351 * then it hasn't been mounted yet.
352 */
353 if (!devfs) {
354 struct stat stst;
355 dev_t root_devno;
356
357 stat("/", &stst);
358 root_devno = stst.st_dev;
359 if (stat("/dev", &stst) != 0)
360 warning("Can't stat /dev: %m");
361 else if (stst.st_dev == root_devno)
362 devfs++;
363 }
364
365 if (devfs) {
366 struct iovec iov[4];
367 char *s;
368 int i;
369
370 char _fstype[] = "fstype";
371 char _devfs[] = "devfs";
372 char _fspath[] = "fspath";
373 char _path_dev[]= _PATH_DEV;
374
375 iov[0].iov_base = _fstype;
376 iov[0].iov_len = sizeof(_fstype);
377 iov[1].iov_base = _devfs;
378 iov[1].iov_len = sizeof(_devfs);
379 iov[2].iov_base = _fspath;
380 iov[2].iov_len = sizeof(_fspath);
381 /*
382 * Try to avoid the trailing slash in _PATH_DEV.
383 * Be *very* defensive.
384 */
385 s = strdup(_PATH_DEV);
386 if (s != NULL) {
387 i = strlen(s);
388 if (i > 0 && s[i - 1] == '/')
389 s[i - 1] = '\0';
390 iov[3].iov_base = s;
391 iov[3].iov_len = strlen(s) + 1;
392 } else {
393 iov[3].iov_base = _path_dev;
394 iov[3].iov_len = sizeof(_path_dev);
395 }
396 nmount(iov, 4, 0);
397 if (s != NULL)
398 free(s);
399 }
400
401 if (initial_transition != reroot_phase_two) {
402 /*
403 * Unmount reroot leftovers. This runs after init(8)
404 * gets reexecuted after reroot_phase_two() is done.
405 */
406 error = unmount(_PATH_REROOT, MNT_FORCE);
407 if (error != 0 && errno != EINVAL)
408 warning("Cannot unmount %s: %m", _PATH_REROOT);
409 }
410
411 /*
412 * Start the state machine.
413 */
414 transition(initial_transition);
415
416 /*
417 * Should never reach here.
418 */
419 return 1;
420 }
421
422 /*
423 * Associate a function with a signal handler.
424 */
425 static void
handle(sig_t handler,...)426 handle(sig_t handler, ...)
427 {
428 int sig;
429 struct sigaction sa;
430 sigset_t mask_everything;
431 va_list ap;
432 va_start(ap, handler);
433
434 sa.sa_handler = handler;
435 sigfillset(&mask_everything);
436
437 while ((sig = va_arg(ap, int)) != 0) {
438 sa.sa_mask = mask_everything;
439 /* XXX SA_RESTART? */
440 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
441 sigaction(sig, &sa, NULL);
442 }
443 va_end(ap);
444 }
445
446 /*
447 * Delete a set of signals from a mask.
448 */
449 static void
delset(sigset_t * maskp,...)450 delset(sigset_t *maskp, ...)
451 {
452 int sig;
453 va_list ap;
454 va_start(ap, maskp);
455
456 while ((sig = va_arg(ap, int)) != 0)
457 sigdelset(maskp, sig);
458 va_end(ap);
459 }
460
461 /*
462 * Log a message and sleep for a while (to give someone an opportunity
463 * to read it and to save log or hardcopy output if the problem is chronic).
464 * NB: should send a message to the session logger to avoid blocking.
465 */
466 static void
stall(const char * message,...)467 stall(const char *message, ...)
468 {
469 va_list ap;
470 va_start(ap, message);
471
472 vsyslog(LOG_ALERT, message, ap);
473 va_end(ap);
474 sleep(STALL_TIMEOUT);
475 }
476
477 /*
478 * Like stall(), but doesn't sleep.
479 * If cpp had variadic macros, the two functions could be #defines for another.
480 * NB: should send a message to the session logger to avoid blocking.
481 */
482 static void
warning(const char * message,...)483 warning(const char *message, ...)
484 {
485 va_list ap;
486 va_start(ap, message);
487
488 vsyslog(LOG_ALERT, message, ap);
489 va_end(ap);
490 }
491
492 /*
493 * Log an emergency message.
494 * NB: should send a message to the session logger to avoid blocking.
495 */
496 static void
emergency(const char * message,...)497 emergency(const char *message, ...)
498 {
499 va_list ap;
500 va_start(ap, message);
501
502 vsyslog(LOG_EMERG, message, ap);
503 va_end(ap);
504 }
505
506 /*
507 * Catch an unexpected signal.
508 */
509 static void
disaster(int sig)510 disaster(int sig)
511 {
512
513 emergency("fatal signal: %s",
514 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
515
516 sleep(STALL_TIMEOUT);
517 _exit(sig); /* reboot */
518 }
519
520 /*
521 * Get the security level of the kernel.
522 */
523 static int
getsecuritylevel(void)524 getsecuritylevel(void)
525 {
526 #ifdef KERN_SECURELVL
527 int name[2], curlevel;
528 size_t len;
529
530 name[0] = CTL_KERN;
531 name[1] = KERN_SECURELVL;
532 len = sizeof curlevel;
533 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
534 emergency("cannot get kernel security level: %m");
535 return (-1);
536 }
537 return (curlevel);
538 #else
539 return (-1);
540 #endif
541 }
542
543 /*
544 * Set the security level of the kernel.
545 */
546 static void
setsecuritylevel(int newlevel)547 setsecuritylevel(int newlevel)
548 {
549 #ifdef KERN_SECURELVL
550 int name[2], curlevel;
551
552 curlevel = getsecuritylevel();
553 if (newlevel == curlevel)
554 return;
555 name[0] = CTL_KERN;
556 name[1] = KERN_SECURELVL;
557 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
558 emergency(
559 "cannot change kernel security level from %d to %d: %m",
560 curlevel, newlevel);
561 return;
562 }
563 #ifdef SECURE
564 warning("kernel security level changed from %d to %d",
565 curlevel, newlevel);
566 #endif
567 #endif
568 }
569
570 /*
571 * Change states in the finite state machine.
572 * The initial state is passed as an argument.
573 */
574 static void
transition(state_t s)575 transition(state_t s)
576 {
577
578 current_state = s;
579 for (;;)
580 current_state = (state_t) (*current_state)();
581 }
582
583 /*
584 * Start a session and allocate a controlling terminal.
585 * Only called by children of init after forking.
586 */
587 static void
open_console(void)588 open_console(void)
589 {
590 int fd;
591
592 /*
593 * Try to open /dev/console. Open the device with O_NONBLOCK to
594 * prevent potential blocking on a carrier.
595 */
596 revoke(_PATH_CONSOLE);
597 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) {
598 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
599 if (login_tty(fd) == 0)
600 return;
601 close(fd);
602 }
603
604 /* No luck. Log output to file if possible. */
605 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
606 stall("cannot open null device.");
607 _exit(1);
608 }
609 if (fd != STDIN_FILENO) {
610 dup2(fd, STDIN_FILENO);
611 close(fd);
612 }
613 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644);
614 if (fd == -1)
615 dup2(STDIN_FILENO, STDOUT_FILENO);
616 else if (fd != STDOUT_FILENO) {
617 dup2(fd, STDOUT_FILENO);
618 close(fd);
619 }
620 dup2(STDOUT_FILENO, STDERR_FILENO);
621 }
622
623 static const char *
get_shell(void)624 get_shell(void)
625 {
626 static char kenv_value[PATH_MAX];
627
628 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
629 return kenv_value;
630 else
631 return _PATH_BSHELL;
632 }
633
634 static void
write_stderr(const char * message)635 write_stderr(const char *message)
636 {
637
638 write(STDERR_FILENO, message, strlen(message));
639 }
640
641 static int
read_file(const char * path,void ** bufp,size_t * bufsizep)642 read_file(const char *path, void **bufp, size_t *bufsizep)
643 {
644 struct stat sb;
645 size_t bufsize;
646 void *buf;
647 ssize_t nbytes;
648 int error, fd;
649
650 fd = open(path, O_RDONLY);
651 if (fd < 0) {
652 emergency("%s: %m", path);
653 return (-1);
654 }
655
656 error = fstat(fd, &sb);
657 if (error != 0) {
658 emergency("fstat: %m");
659 close(fd);
660 return (error);
661 }
662
663 bufsize = sb.st_size;
664 buf = malloc(bufsize);
665 if (buf == NULL) {
666 emergency("malloc: %m");
667 close(fd);
668 return (error);
669 }
670
671 nbytes = read(fd, buf, bufsize);
672 if (nbytes != (ssize_t)bufsize) {
673 emergency("read: %m");
674 close(fd);
675 free(buf);
676 return (error);
677 }
678
679 error = close(fd);
680 if (error != 0) {
681 emergency("close: %m");
682 free(buf);
683 return (error);
684 }
685
686 *bufp = buf;
687 *bufsizep = bufsize;
688
689 return (0);
690 }
691
692 static int
create_file(const char * path,const void * buf,size_t bufsize)693 create_file(const char *path, const void *buf, size_t bufsize)
694 {
695 ssize_t nbytes;
696 int error, fd;
697
698 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700);
699 if (fd < 0) {
700 emergency("%s: %m", path);
701 return (-1);
702 }
703
704 nbytes = write(fd, buf, bufsize);
705 if (nbytes != (ssize_t)bufsize) {
706 emergency("write: %m");
707 close(fd);
708 return (-1);
709 }
710
711 error = close(fd);
712 if (error != 0) {
713 emergency("close: %m");
714 return (-1);
715 }
716
717 return (0);
718 }
719
720 static int
mount_tmpfs(const char * fspath)721 mount_tmpfs(const char *fspath)
722 {
723 struct iovec *iov;
724 char errmsg[255];
725 int error, iovlen;
726
727 iov = NULL;
728 iovlen = 0;
729 memset(errmsg, 0, sizeof(errmsg));
730 build_iovec(&iov, &iovlen, "fstype",
731 __DECONST(void *, "tmpfs"), (size_t)-1);
732 build_iovec(&iov, &iovlen, "fspath",
733 __DECONST(void *, fspath), (size_t)-1);
734 build_iovec(&iov, &iovlen, "errmsg",
735 errmsg, sizeof(errmsg));
736
737 error = nmount(iov, iovlen, 0);
738 if (error != 0) {
739 if (*errmsg != '\0') {
740 emergency("cannot mount tmpfs on %s: %s: %m",
741 fspath, errmsg);
742 } else {
743 emergency("cannot mount tmpfs on %s: %m",
744 fspath);
745 }
746 return (error);
747 }
748 return (0);
749 }
750
751 static state_func_t
reroot(void)752 reroot(void)
753 {
754 void *buf;
755 size_t bufsize;
756 int error;
757
758 buf = NULL;
759 bufsize = 0;
760
761 revoke_ttys();
762 runshutdown();
763
764 /*
765 * Make sure nobody can interfere with our scheme.
766 * Ignore ESRCH, which can apparently happen when
767 * there are no processes to kill.
768 */
769 error = kill(-1, SIGKILL);
770 if (error != 0 && errno != ESRCH) {
771 emergency("kill(2) failed: %m");
772 goto out;
773 }
774
775 /*
776 * Copy the init binary into tmpfs, so that we can unmount
777 * the old rootfs without committing suicide.
778 */
779 error = read_file(init_path_argv0, &buf, &bufsize);
780 if (error != 0)
781 goto out;
782 error = mount_tmpfs(_PATH_REROOT);
783 if (error != 0)
784 goto out;
785 error = create_file(_PATH_REROOT_INIT, buf, bufsize);
786 if (error != 0)
787 goto out;
788
789 /*
790 * Execute the temporary init.
791 */
792 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL);
793 emergency("cannot exec %s: %m", _PATH_REROOT_INIT);
794
795 out:
796 emergency("reroot failed; going to single user mode");
797 free(buf);
798 return (state_func_t) single_user;
799 }
800
801 static state_func_t
reroot_phase_two(void)802 reroot_phase_two(void)
803 {
804 char init_path[PATH_MAX], *path, *path_component;
805 size_t init_path_len;
806 int nbytes, error;
807
808 /*
809 * Ask the kernel to mount the new rootfs.
810 */
811 error = reboot(RB_REROOT);
812 if (error != 0) {
813 emergency("RB_REBOOT failed: %m");
814 goto out;
815 }
816
817 /*
818 * Figure out where the destination init(8) binary is. Note that
819 * the path could be different than what we've started with. Use
820 * the value from kenv, if set, or the one from sysctl otherwise.
821 * The latter defaults to a hardcoded value, but can be overridden
822 * by a build time option.
823 */
824 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path));
825 if (nbytes <= 0) {
826 init_path_len = sizeof(init_path);
827 error = sysctlbyname("kern.init_path",
828 init_path, &init_path_len, NULL, 0);
829 if (error != 0) {
830 emergency("failed to retrieve kern.init_path: %m");
831 goto out;
832 }
833 }
834
835 /*
836 * Repeat the init search logic from sys/kern/init_path.c
837 */
838 path_component = init_path;
839 while ((path = strsep(&path_component, ":")) != NULL) {
840 /*
841 * Execute init(8) from the new rootfs.
842 */
843 execl(path, path, NULL);
844 }
845 emergency("cannot exec init from %s: %m", init_path);
846
847 out:
848 emergency("reroot failed; going to single user mode");
849 return (state_func_t) single_user;
850 }
851
852 /*
853 * Bring the system up single user.
854 */
855 static state_func_t
single_user(void)856 single_user(void)
857 {
858 pid_t pid, wpid;
859 int status;
860 sigset_t mask;
861 const char *shell;
862 char *argv[2];
863 struct timeval tv, tn;
864 #ifdef SECURE
865 struct ttyent *typ;
866 struct passwd *pp;
867 static const char banner[] =
868 "Enter root password, or ^D to go multi-user\n";
869 char *clear, *password;
870 #endif
871 #ifdef DEBUGSHELL
872 char altshell[128];
873 #endif
874
875 if (Reboot) {
876 /* Instead of going single user, let's reboot the machine */
877 sync();
878 /* Run scripts after all processes have been terminated. */
879 runfinal();
880 if (reboot(howto) == -1) {
881 emergency("reboot(%#x) failed, %m", howto);
882 _exit(1); /* panic and reboot */
883 }
884 warning("reboot(%#x) returned", howto);
885 _exit(0); /* panic as well */
886 }
887
888 shell = get_shell();
889
890 if ((pid = fork()) == 0) {
891 /*
892 * Start the single user session.
893 */
894 open_console();
895
896 #ifdef SECURE
897 /*
898 * Check the root password.
899 * We don't care if the console is 'on' by default;
900 * it's the only tty that can be 'off' and 'secure'.
901 */
902 typ = getttynam("console");
903 pp = getpwnam("root");
904 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
905 pp && *pp->pw_passwd) {
906 write_stderr(banner);
907 for (;;) {
908 clear = getpass("Password:");
909 if (clear == NULL || *clear == '\0')
910 _exit(0);
911 password = crypt(clear, pp->pw_passwd);
912 explicit_bzero(clear, _PASSWORD_LEN);
913 if (password != NULL &&
914 strcmp(password, pp->pw_passwd) == 0)
915 break;
916 warning("single-user login failed\n");
917 }
918 }
919 endttyent();
920 endpwent();
921 #endif /* SECURE */
922
923 #ifdef DEBUGSHELL
924 {
925 char *cp = altshell;
926 int num;
927
928 #define SHREQUEST "Enter full pathname of shell or RETURN for "
929 write_stderr(SHREQUEST);
930 write_stderr(shell);
931 write_stderr(": ");
932 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
933 num != 0 && *cp != '\n' && cp < &altshell[127])
934 cp++;
935 *cp = '\0';
936 if (altshell[0] != '\0')
937 shell = altshell;
938 }
939 #endif /* DEBUGSHELL */
940
941 /*
942 * Unblock signals.
943 * We catch all the interesting ones,
944 * and those are reset to SIG_DFL on exec.
945 */
946 sigemptyset(&mask);
947 sigprocmask(SIG_SETMASK, &mask, NULL);
948
949 /*
950 * Fire off a shell.
951 * If the default one doesn't work, try the Bourne shell.
952 */
953
954 char name[] = "-sh";
955
956 argv[0] = name;
957 argv[1] = NULL;
958 execv(shell, argv);
959 emergency("can't exec %s for single user: %m", shell);
960 execv(_PATH_BSHELL, argv);
961 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
962 sleep(STALL_TIMEOUT);
963 _exit(1);
964 }
965
966 if (pid == -1) {
967 /*
968 * We are seriously hosed. Do our best.
969 */
970 emergency("can't fork single-user shell, trying again");
971 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
972 continue;
973 return (state_func_t) single_user;
974 }
975
976 requested_transition = 0;
977 do {
978 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
979 collect_child(wpid);
980 if (wpid == -1) {
981 if (errno == EINTR)
982 continue;
983 warning("wait for single-user shell failed: %m; restarting");
984 return (state_func_t) single_user;
985 }
986 if (wpid == pid && WIFSTOPPED(status)) {
987 warning("init: shell stopped, restarting\n");
988 kill(pid, SIGCONT);
989 wpid = -1;
990 }
991 } while (wpid != pid && !requested_transition);
992
993 if (requested_transition)
994 return (state_func_t) requested_transition;
995
996 if (!WIFEXITED(status)) {
997 if (WTERMSIG(status) == SIGKILL) {
998 /*
999 * reboot(8) killed shell?
1000 */
1001 warning("single user shell terminated.");
1002 gettimeofday(&tv, NULL);
1003 tn = tv;
1004 tv.tv_sec += STALL_TIMEOUT;
1005 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec ==
1006 tn.tv_sec && tv.tv_usec > tn.tv_usec)) {
1007 sleep(1);
1008 gettimeofday(&tn, NULL);
1009 }
1010 _exit(0);
1011 } else {
1012 warning("single user shell terminated, restarting");
1013 return (state_func_t) single_user;
1014 }
1015 }
1016
1017 runcom_mode = FASTBOOT;
1018 return (state_func_t) runcom;
1019 }
1020
1021 /*
1022 * Run the system startup script.
1023 */
1024 static state_func_t
runcom(void)1025 runcom(void)
1026 {
1027 state_func_t next_transition;
1028
1029 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL)
1030 return next_transition;
1031
1032 runcom_mode = AUTOBOOT; /* the default */
1033 return (state_func_t) read_ttys;
1034 }
1035
1036 static void
execute_script(char * argv[])1037 execute_script(char *argv[])
1038 {
1039 struct sigaction sa;
1040 const char *shell, *script;
1041 int error;
1042
1043 bzero(&sa, sizeof(sa));
1044 sigemptyset(&sa.sa_mask);
1045 sa.sa_handler = SIG_IGN;
1046 sigaction(SIGTSTP, &sa, NULL);
1047 sigaction(SIGHUP, &sa, NULL);
1048
1049 open_console();
1050
1051 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1052 #ifdef LOGIN_CAP
1053 setprocresources(RESOURCE_RC);
1054 #endif
1055
1056 /*
1057 * Try to directly execute the script first. If it
1058 * fails, try the old method of passing the script path
1059 * to sh(1). Don't complain if it fails because of
1060 * the missing execute bit.
1061 */
1062 script = argv[1];
1063 error = access(script, X_OK);
1064 if (error == 0) {
1065 execv(script, argv + 1);
1066 warning("can't directly exec %s: %m", script);
1067 } else if (errno != EACCES) {
1068 warning("can't access %s: %m", script);
1069 }
1070
1071 shell = get_shell();
1072 execv(shell, argv);
1073 stall("can't exec %s for %s: %m", shell, script);
1074 }
1075
1076 /*
1077 * Execute binary, replacing init(8) as PID 1.
1078 */
1079 static void
replace_init(char * path)1080 replace_init(char *path)
1081 {
1082 char *argv[3];
1083 char sh[] = "sh";
1084
1085 argv[0] = sh;
1086 argv[1] = path;
1087 argv[2] = NULL;
1088
1089 execute_script(argv);
1090 }
1091
1092 /*
1093 * Run a shell script.
1094 * Returns 0 on success, otherwise the next transition to enter:
1095 * - single_user if fork/execv/waitpid failed, or if the script
1096 * terminated with a signal or exit code != 0.
1097 * - death_single if a SIGTERM was delivered to init(8).
1098 */
1099 static state_func_t
run_script(const char * script)1100 run_script(const char *script)
1101 {
1102 pid_t pid, wpid;
1103 int status;
1104 char *argv[4];
1105 const char *shell;
1106
1107 shell = get_shell();
1108
1109 if ((pid = fork()) == 0) {
1110
1111 char _sh[] = "sh";
1112 char _autoboot[] = "autoboot";
1113
1114 argv[0] = _sh;
1115 argv[1] = __DECONST(char *, script);
1116 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0;
1117 argv[3] = NULL;
1118
1119 execute_script(argv);
1120 sleep(STALL_TIMEOUT);
1121 _exit(1); /* force single user mode */
1122 }
1123
1124 if (pid == -1) {
1125 emergency("can't fork for %s on %s: %m", shell, script);
1126 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1127 continue;
1128 sleep(STALL_TIMEOUT);
1129 return (state_func_t) single_user;
1130 }
1131
1132 /*
1133 * Copied from single_user(). This is a bit paranoid.
1134 */
1135 requested_transition = 0;
1136 do {
1137 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1138 collect_child(wpid);
1139 if (requested_transition == death_single ||
1140 requested_transition == reroot)
1141 return (state_func_t) requested_transition;
1142 if (wpid == -1) {
1143 if (errno == EINTR)
1144 continue;
1145 warning("wait for %s on %s failed: %m; going to "
1146 "single user mode", shell, script);
1147 return (state_func_t) single_user;
1148 }
1149 if (wpid == pid && WIFSTOPPED(status)) {
1150 warning("init: %s on %s stopped, restarting\n",
1151 shell, script);
1152 kill(pid, SIGCONT);
1153 wpid = -1;
1154 }
1155 } while (wpid != pid);
1156
1157 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1158 requested_transition == catatonia) {
1159 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
1160 sigset_t s;
1161
1162 sigfillset(&s);
1163 for (;;)
1164 sigsuspend(&s);
1165 }
1166
1167 if (!WIFEXITED(status)) {
1168 warning("%s on %s terminated abnormally, going to single "
1169 "user mode", shell, script);
1170 return (state_func_t) single_user;
1171 }
1172
1173 if (WEXITSTATUS(status))
1174 return (state_func_t) single_user;
1175
1176 return (state_func_t) 0;
1177 }
1178
1179 /*
1180 * Open the session database.
1181 *
1182 * NB: We could pass in the size here; is it necessary?
1183 */
1184 static int
start_session_db(void)1185 start_session_db(void)
1186 {
1187 if (session_db && (*session_db->close)(session_db))
1188 emergency("session database close: %m");
1189 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) {
1190 emergency("session database open: %m");
1191 return (1);
1192 }
1193 return (0);
1194
1195 }
1196
1197 /*
1198 * Add a new login session.
1199 */
1200 static void
add_session(session_t * sp)1201 add_session(session_t *sp)
1202 {
1203 DBT key;
1204 DBT data;
1205
1206 key.data = &sp->se_process;
1207 key.size = sizeof sp->se_process;
1208 data.data = &sp;
1209 data.size = sizeof sp;
1210
1211 if ((*session_db->put)(session_db, &key, &data, 0))
1212 emergency("insert %d: %m", sp->se_process);
1213 }
1214
1215 /*
1216 * Delete an old login session.
1217 */
1218 static void
del_session(session_t * sp)1219 del_session(session_t *sp)
1220 {
1221 DBT key;
1222
1223 key.data = &sp->se_process;
1224 key.size = sizeof sp->se_process;
1225
1226 if ((*session_db->del)(session_db, &key, 0))
1227 emergency("delete %d: %m", sp->se_process);
1228 }
1229
1230 /*
1231 * Look up a login session by pid.
1232 */
1233 static session_t *
find_session(pid_t pid)1234 find_session(pid_t pid)
1235 {
1236 DBT key;
1237 DBT data;
1238 session_t *ret;
1239
1240 key.data = &pid;
1241 key.size = sizeof pid;
1242 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
1243 return 0;
1244 bcopy(data.data, (char *)&ret, sizeof(ret));
1245 return ret;
1246 }
1247
1248 /*
1249 * Construct an argument vector from a command line.
1250 */
1251 static char **
construct_argv(char * command)1252 construct_argv(char *command)
1253 {
1254 int argc = 0;
1255 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
1256 * sizeof (char *));
1257
1258 if ((argv[argc++] = strk(command)) == NULL) {
1259 free(argv);
1260 return (NULL);
1261 }
1262 while ((argv[argc++] = strk((char *) 0)) != NULL)
1263 continue;
1264 return argv;
1265 }
1266
1267 /*
1268 * Deallocate a session descriptor.
1269 */
1270 static void
free_session(session_t * sp)1271 free_session(session_t *sp)
1272 {
1273 free(sp->se_device);
1274 if (sp->se_getty) {
1275 free(sp->se_getty);
1276 free(sp->se_getty_argv_space);
1277 free(sp->se_getty_argv);
1278 }
1279 if (sp->se_window) {
1280 free(sp->se_window);
1281 free(sp->se_window_argv_space);
1282 free(sp->se_window_argv);
1283 }
1284 if (sp->se_type)
1285 free(sp->se_type);
1286 free(sp);
1287 }
1288
1289 /*
1290 * Allocate a new session descriptor.
1291 * Mark it SE_PRESENT.
1292 */
1293 static session_t *
new_session(session_t * sprev,struct ttyent * typ)1294 new_session(session_t *sprev, struct ttyent *typ)
1295 {
1296 session_t *sp;
1297
1298 if ((typ->ty_status & TTY_ON) == 0 ||
1299 typ->ty_name == 0 ||
1300 typ->ty_getty == 0)
1301 return 0;
1302
1303 sp = (session_t *) calloc(1, sizeof (session_t));
1304
1305 sp->se_flags |= SE_PRESENT;
1306
1307 if ((typ->ty_status & TTY_IFEXISTS) != 0)
1308 sp->se_flags |= SE_IFEXISTS;
1309
1310 if ((typ->ty_status & TTY_IFCONSOLE) != 0)
1311 sp->se_flags |= SE_IFCONSOLE;
1312
1313 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0)
1314 err(1, "asprintf");
1315
1316 if (setupargv(sp, typ) == 0) {
1317 free_session(sp);
1318 return (0);
1319 }
1320
1321 sp->se_next = 0;
1322 if (sprev == NULL) {
1323 sessions = sp;
1324 sp->se_prev = 0;
1325 } else {
1326 sprev->se_next = sp;
1327 sp->se_prev = sprev;
1328 }
1329
1330 return sp;
1331 }
1332
1333 /*
1334 * Calculate getty and if useful window argv vectors.
1335 */
1336 static int
setupargv(session_t * sp,struct ttyent * typ)1337 setupargv(session_t *sp, struct ttyent *typ)
1338 {
1339
1340 if (sp->se_getty) {
1341 free(sp->se_getty);
1342 free(sp->se_getty_argv_space);
1343 free(sp->se_getty_argv);
1344 }
1345 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0)
1346 err(1, "asprintf");
1347 sp->se_getty_argv_space = strdup(sp->se_getty);
1348 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1349 if (sp->se_getty_argv == NULL) {
1350 warning("can't parse getty for port %s", sp->se_device);
1351 free(sp->se_getty);
1352 free(sp->se_getty_argv_space);
1353 sp->se_getty = sp->se_getty_argv_space = 0;
1354 return (0);
1355 }
1356 if (sp->se_window) {
1357 free(sp->se_window);
1358 free(sp->se_window_argv_space);
1359 free(sp->se_window_argv);
1360 }
1361 sp->se_window = sp->se_window_argv_space = 0;
1362 sp->se_window_argv = 0;
1363 if (typ->ty_window) {
1364 sp->se_window = strdup(typ->ty_window);
1365 sp->se_window_argv_space = strdup(sp->se_window);
1366 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1367 if (sp->se_window_argv == NULL) {
1368 warning("can't parse window for port %s",
1369 sp->se_device);
1370 free(sp->se_window_argv_space);
1371 free(sp->se_window);
1372 sp->se_window = sp->se_window_argv_space = 0;
1373 return (0);
1374 }
1375 }
1376 if (sp->se_type)
1377 free(sp->se_type);
1378 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1379 return (1);
1380 }
1381
1382 /*
1383 * Walk the list of ttys and create sessions for each active line.
1384 */
1385 static state_func_t
read_ttys(void)1386 read_ttys(void)
1387 {
1388 session_t *sp, *snext;
1389 struct ttyent *typ;
1390
1391 /*
1392 * Destroy any previous session state.
1393 * There shouldn't be any, but just in case...
1394 */
1395 for (sp = sessions; sp; sp = snext) {
1396 snext = sp->se_next;
1397 free_session(sp);
1398 }
1399 sessions = 0;
1400 if (start_session_db())
1401 return (state_func_t) single_user;
1402
1403 /*
1404 * Allocate a session entry for each active port.
1405 * Note that sp starts at 0.
1406 */
1407 while ((typ = getttyent()) != NULL)
1408 if ((snext = new_session(sp, typ)) != NULL)
1409 sp = snext;
1410
1411 endttyent();
1412
1413 return (state_func_t) multi_user;
1414 }
1415
1416 /*
1417 * Start a window system running.
1418 */
1419 static void
start_window_system(session_t * sp)1420 start_window_system(session_t *sp)
1421 {
1422 pid_t pid;
1423 sigset_t mask;
1424 char term[64], *env[2];
1425 int status;
1426
1427 if ((pid = fork()) == -1) {
1428 emergency("can't fork for window system on port %s: %m",
1429 sp->se_device);
1430 /* hope that getty fails and we can try again */
1431 return;
1432 }
1433 if (pid) {
1434 waitpid(-1, &status, 0);
1435 return;
1436 }
1437
1438 /* reparent window process to the init to not make a zombie on exit */
1439 if ((pid = fork()) == -1) {
1440 emergency("can't fork for window system on port %s: %m",
1441 sp->se_device);
1442 _exit(1);
1443 }
1444 if (pid)
1445 _exit(0);
1446
1447 sigemptyset(&mask);
1448 sigprocmask(SIG_SETMASK, &mask, NULL);
1449
1450 if (setsid() < 0)
1451 emergency("setsid failed (window) %m");
1452
1453 #ifdef LOGIN_CAP
1454 setprocresources(RESOURCE_WINDOW);
1455 #endif
1456 if (sp->se_type) {
1457 /* Don't use malloc after fork */
1458 strcpy(term, "TERM=");
1459 strlcat(term, sp->se_type, sizeof(term));
1460 env[0] = term;
1461 env[1] = NULL;
1462 }
1463 else
1464 env[0] = NULL;
1465 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1466 stall("can't exec window system '%s' for port %s: %m",
1467 sp->se_window_argv[0], sp->se_device);
1468 _exit(1);
1469 }
1470
1471 /*
1472 * Start a login session running.
1473 */
1474 static pid_t
start_getty(session_t * sp)1475 start_getty(session_t *sp)
1476 {
1477 pid_t pid;
1478 sigset_t mask;
1479 time_t current_time = time((time_t *) 0);
1480 int too_quick = 0;
1481 char term[64], *env[2];
1482
1483 if (current_time >= sp->se_started &&
1484 current_time - sp->se_started < GETTY_SPACING) {
1485 if (++sp->se_nspace > GETTY_NSPACE) {
1486 sp->se_nspace = 0;
1487 too_quick = 1;
1488 }
1489 } else
1490 sp->se_nspace = 0;
1491
1492 /*
1493 * fork(), not vfork() -- we can't afford to block.
1494 */
1495 if ((pid = fork()) == -1) {
1496 emergency("can't fork for getty on port %s: %m", sp->se_device);
1497 return -1;
1498 }
1499
1500 if (pid)
1501 return pid;
1502
1503 if (too_quick) {
1504 warning("getty repeating too quickly on port %s, sleeping %d secs",
1505 sp->se_device, GETTY_SLEEP);
1506 sleep((unsigned) GETTY_SLEEP);
1507 }
1508
1509 if (sp->se_window) {
1510 start_window_system(sp);
1511 sleep(WINDOW_WAIT);
1512 }
1513
1514 sigemptyset(&mask);
1515 sigprocmask(SIG_SETMASK, &mask, NULL);
1516
1517 #ifdef LOGIN_CAP
1518 setprocresources(RESOURCE_GETTY);
1519 #endif
1520 if (sp->se_type) {
1521 /* Don't use malloc after fork */
1522 strcpy(term, "TERM=");
1523 strlcat(term, sp->se_type, sizeof(term));
1524 env[0] = term;
1525 env[1] = NULL;
1526 } else
1527 env[0] = NULL;
1528 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1529 stall("can't exec getty '%s' for port %s: %m",
1530 sp->se_getty_argv[0], sp->se_device);
1531 _exit(1);
1532 }
1533
1534 /*
1535 * Return 1 if the session is defined as "onifexists"
1536 * or "onifconsole" and the device node does not exist.
1537 */
1538 static int
session_has_no_tty(session_t * sp)1539 session_has_no_tty(session_t *sp)
1540 {
1541 int fd;
1542
1543 if ((sp->se_flags & SE_IFEXISTS) == 0 &&
1544 (sp->se_flags & SE_IFCONSOLE) == 0)
1545 return (0);
1546
1547 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0);
1548 if (fd < 0) {
1549 if (errno == ENOENT)
1550 return (1);
1551 return (0);
1552 }
1553
1554 close(fd);
1555 return (0);
1556 }
1557
1558 /*
1559 * Collect exit status for a child.
1560 * If an exiting login, start a new login running.
1561 */
1562 static void
collect_child(pid_t pid)1563 collect_child(pid_t pid)
1564 {
1565 session_t *sp, *sprev, *snext;
1566
1567 if (! sessions)
1568 return;
1569
1570 if (! (sp = find_session(pid)))
1571 return;
1572
1573 del_session(sp);
1574 sp->se_process = 0;
1575
1576 if (sp->se_flags & SE_SHUTDOWN ||
1577 session_has_no_tty(sp)) {
1578 if ((sprev = sp->se_prev) != NULL)
1579 sprev->se_next = sp->se_next;
1580 else
1581 sessions = sp->se_next;
1582 if ((snext = sp->se_next) != NULL)
1583 snext->se_prev = sp->se_prev;
1584 free_session(sp);
1585 return;
1586 }
1587
1588 if ((pid = start_getty(sp)) == -1) {
1589 /* serious trouble */
1590 requested_transition = clean_ttys;
1591 return;
1592 }
1593
1594 sp->se_process = pid;
1595 sp->se_started = time((time_t *) 0);
1596 add_session(sp);
1597 }
1598
1599 /*
1600 * Catch a signal and request a state transition.
1601 */
1602 static void
transition_handler(int sig)1603 transition_handler(int sig)
1604 {
1605
1606 switch (sig) {
1607 case SIGHUP:
1608 if (current_state == read_ttys || current_state == multi_user ||
1609 current_state == clean_ttys || current_state == catatonia)
1610 requested_transition = clean_ttys;
1611 break;
1612 case SIGUSR2:
1613 howto = RB_POWEROFF;
1614 case SIGUSR1:
1615 howto |= RB_HALT;
1616 case SIGWINCH:
1617 case SIGINT:
1618 if (sig == SIGWINCH)
1619 howto |= RB_POWERCYCLE;
1620 Reboot = TRUE;
1621 case SIGTERM:
1622 if (current_state == read_ttys || current_state == multi_user ||
1623 current_state == clean_ttys || current_state == catatonia)
1624 requested_transition = death;
1625 else
1626 requested_transition = death_single;
1627 break;
1628 case SIGTSTP:
1629 if (current_state == runcom || current_state == read_ttys ||
1630 current_state == clean_ttys ||
1631 current_state == multi_user || current_state == catatonia)
1632 requested_transition = catatonia;
1633 break;
1634 case SIGEMT:
1635 requested_transition = reroot;
1636 break;
1637 default:
1638 requested_transition = 0;
1639 break;
1640 }
1641 }
1642
1643 /*
1644 * Take the system multiuser.
1645 */
1646 static state_func_t
multi_user(void)1647 multi_user(void)
1648 {
1649 pid_t pid;
1650 session_t *sp;
1651
1652 requested_transition = 0;
1653
1654 /*
1655 * If the administrator has not set the security level to -1
1656 * to indicate that the kernel should not run multiuser in secure
1657 * mode, and the run script has not set a higher level of security
1658 * than level 1, then put the kernel into secure mode.
1659 */
1660 if (getsecuritylevel() == 0)
1661 setsecuritylevel(1);
1662
1663 for (sp = sessions; sp; sp = sp->se_next) {
1664 if (sp->se_process)
1665 continue;
1666 if (session_has_no_tty(sp))
1667 continue;
1668 if ((pid = start_getty(sp)) == -1) {
1669 /* serious trouble */
1670 requested_transition = clean_ttys;
1671 break;
1672 }
1673 sp->se_process = pid;
1674 sp->se_started = time((time_t *) 0);
1675 add_session(sp);
1676 }
1677
1678 while (!requested_transition)
1679 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1680 collect_child(pid);
1681
1682 return (state_func_t) requested_transition;
1683 }
1684
1685 /*
1686 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1687 */
1688 static state_func_t
clean_ttys(void)1689 clean_ttys(void)
1690 {
1691 session_t *sp, *sprev;
1692 struct ttyent *typ;
1693 int devlen;
1694 char *old_getty, *old_window, *old_type;
1695
1696 /*
1697 * mark all sessions for death, (!SE_PRESENT)
1698 * as we find or create new ones they'll be marked as keepers,
1699 * we'll later nuke all the ones not found in /etc/ttys
1700 */
1701 for (sp = sessions; sp != NULL; sp = sp->se_next)
1702 sp->se_flags &= ~SE_PRESENT;
1703
1704 devlen = sizeof(_PATH_DEV) - 1;
1705 while ((typ = getttyent()) != NULL) {
1706 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1707 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1708 break;
1709
1710 if (sp) {
1711 /* we want this one to live */
1712 sp->se_flags |= SE_PRESENT;
1713 if ((typ->ty_status & TTY_ON) == 0 ||
1714 typ->ty_getty == 0) {
1715 sp->se_flags |= SE_SHUTDOWN;
1716 kill(sp->se_process, SIGHUP);
1717 continue;
1718 }
1719 sp->se_flags &= ~SE_SHUTDOWN;
1720 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1721 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1722 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1723 if (setupargv(sp, typ) == 0) {
1724 warning("can't parse getty for port %s",
1725 sp->se_device);
1726 sp->se_flags |= SE_SHUTDOWN;
1727 kill(sp->se_process, SIGHUP);
1728 }
1729 else if ( !old_getty
1730 || (!old_type && sp->se_type)
1731 || (old_type && !sp->se_type)
1732 || (!old_window && sp->se_window)
1733 || (old_window && !sp->se_window)
1734 || (strcmp(old_getty, sp->se_getty) != 0)
1735 || (old_window && strcmp(old_window, sp->se_window) != 0)
1736 || (old_type && strcmp(old_type, sp->se_type) != 0)
1737 ) {
1738 /* Don't set SE_SHUTDOWN here */
1739 sp->se_nspace = 0;
1740 sp->se_started = 0;
1741 kill(sp->se_process, SIGHUP);
1742 }
1743 if (old_getty)
1744 free(old_getty);
1745 if (old_window)
1746 free(old_window);
1747 if (old_type)
1748 free(old_type);
1749 continue;
1750 }
1751
1752 new_session(sprev, typ);
1753 }
1754
1755 endttyent();
1756
1757 /*
1758 * sweep through and kill all deleted sessions
1759 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1760 */
1761 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1762 if ((sp->se_flags & SE_PRESENT) == 0) {
1763 sp->se_flags |= SE_SHUTDOWN;
1764 kill(sp->se_process, SIGHUP);
1765 }
1766 }
1767
1768 return (state_func_t) multi_user;
1769 }
1770
1771 /*
1772 * Block further logins.
1773 */
1774 static state_func_t
catatonia(void)1775 catatonia(void)
1776 {
1777 session_t *sp;
1778
1779 for (sp = sessions; sp; sp = sp->se_next)
1780 sp->se_flags |= SE_SHUTDOWN;
1781
1782 return (state_func_t) multi_user;
1783 }
1784
1785 /*
1786 * Note SIGALRM.
1787 */
1788 static void
alrm_handler(int sig)1789 alrm_handler(int sig)
1790 {
1791
1792 (void)sig;
1793 clang = 1;
1794 }
1795
1796 /*
1797 * Bring the system down to single user.
1798 */
1799 static state_func_t
death(void)1800 death(void)
1801 {
1802 int block, blocked;
1803 size_t len;
1804
1805 /* Temporarily block suspend. */
1806 len = sizeof(blocked);
1807 block = 1;
1808 if (sysctlbyname("kern.suspend_blocked", &blocked, &len,
1809 &block, sizeof(block)) == -1)
1810 blocked = 0;
1811
1812 /*
1813 * Also revoke the TTY here. Because runshutdown() may reopen
1814 * the TTY whose getty we're killing here, there is no guarantee
1815 * runshutdown() will perform the initial open() call, causing
1816 * the terminal attributes to be misconfigured.
1817 */
1818 revoke_ttys();
1819
1820 /* Try to run the rc.shutdown script within a period of time */
1821 runshutdown();
1822
1823 /* Unblock suspend if we blocked it. */
1824 if (!blocked)
1825 sysctlbyname("kern.suspend_blocked", NULL, NULL,
1826 &blocked, sizeof(blocked));
1827
1828 return (state_func_t) death_single;
1829 }
1830
1831 /*
1832 * Do what is necessary to reinitialize single user mode or reboot
1833 * from an incomplete state.
1834 */
1835 static state_func_t
death_single(void)1836 death_single(void)
1837 {
1838 int i;
1839 pid_t pid;
1840 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1841
1842 revoke(_PATH_CONSOLE);
1843
1844 for (i = 0; i < 2; ++i) {
1845 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1846 return (state_func_t) single_user;
1847
1848 clang = 0;
1849 alarm(DEATH_WATCH);
1850 do
1851 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1852 collect_child(pid);
1853 while (clang == 0 && errno != ECHILD);
1854
1855 if (errno == ECHILD)
1856 return (state_func_t) single_user;
1857 }
1858
1859 warning("some processes would not die; ps axl advised");
1860
1861 return (state_func_t) single_user;
1862 }
1863
1864 static void
revoke_ttys(void)1865 revoke_ttys(void)
1866 {
1867 session_t *sp;
1868
1869 for (sp = sessions; sp; sp = sp->se_next) {
1870 sp->se_flags |= SE_SHUTDOWN;
1871 kill(sp->se_process, SIGHUP);
1872 revoke(sp->se_device);
1873 }
1874 }
1875
1876 /*
1877 * Run the system shutdown script.
1878 *
1879 * Exit codes: XXX I should document more
1880 * -2 shutdown script terminated abnormally
1881 * -1 fatal error - can't run script
1882 * 0 good.
1883 * >0 some error (exit code)
1884 */
1885 static int
runshutdown(void)1886 runshutdown(void)
1887 {
1888 pid_t pid, wpid;
1889 int status;
1890 int shutdowntimeout;
1891 size_t len;
1892 char *argv[4];
1893 struct stat sb;
1894
1895 /*
1896 * rc.shutdown is optional, so to prevent any unnecessary
1897 * complaints from the shell we simply don't run it if the
1898 * file does not exist. If the stat() here fails for other
1899 * reasons, we'll let the shell complain.
1900 */
1901 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1902 return 0;
1903
1904 if ((pid = fork()) == 0) {
1905 char _sh[] = "sh";
1906 char _reboot[] = "reboot";
1907 char _single[] = "single";
1908 char _path_rundown[] = _PATH_RUNDOWN;
1909
1910 argv[0] = _sh;
1911 argv[1] = _path_rundown;
1912 argv[2] = Reboot ? _reboot : _single;
1913 argv[3] = NULL;
1914
1915 execute_script(argv);
1916 _exit(1); /* force single user mode */
1917 }
1918
1919 if (pid == -1) {
1920 emergency("can't fork for %s: %m", _PATH_RUNDOWN);
1921 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1922 continue;
1923 sleep(STALL_TIMEOUT);
1924 return -1;
1925 }
1926
1927 len = sizeof(shutdowntimeout);
1928 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
1929 NULL, 0) == -1 || shutdowntimeout < 2)
1930 shutdowntimeout = DEATH_SCRIPT;
1931 alarm(shutdowntimeout);
1932 clang = 0;
1933 /*
1934 * Copied from single_user(). This is a bit paranoid.
1935 * Use the same ALRM handler.
1936 */
1937 do {
1938 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1939 collect_child(wpid);
1940 if (clang == 1) {
1941 /* we were waiting for the sub-shell */
1942 kill(wpid, SIGTERM);
1943 warning("timeout expired for %s: %m; going to "
1944 "single user mode", _PATH_RUNDOWN);
1945 return -1;
1946 }
1947 if (wpid == -1) {
1948 if (errno == EINTR)
1949 continue;
1950 warning("wait for %s failed: %m; going to "
1951 "single user mode", _PATH_RUNDOWN);
1952 return -1;
1953 }
1954 if (wpid == pid && WIFSTOPPED(status)) {
1955 warning("init: %s stopped, restarting\n",
1956 _PATH_RUNDOWN);
1957 kill(pid, SIGCONT);
1958 wpid = -1;
1959 }
1960 } while (wpid != pid && !clang);
1961
1962 /* Turn off the alarm */
1963 alarm(0);
1964
1965 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1966 requested_transition == catatonia) {
1967 /*
1968 * /etc/rc.shutdown executed /sbin/reboot;
1969 * wait for the end quietly
1970 */
1971 sigset_t s;
1972
1973 sigfillset(&s);
1974 for (;;)
1975 sigsuspend(&s);
1976 }
1977
1978 if (!WIFEXITED(status)) {
1979 warning("%s terminated abnormally, going to "
1980 "single user mode", _PATH_RUNDOWN);
1981 return -2;
1982 }
1983
1984 if ((status = WEXITSTATUS(status)) != 0)
1985 warning("%s returned status %d", _PATH_RUNDOWN, status);
1986
1987 return status;
1988 }
1989
1990 static char *
strk(char * p)1991 strk(char *p)
1992 {
1993 static char *t;
1994 char *q;
1995 int c;
1996
1997 if (p)
1998 t = p;
1999 if (!t)
2000 return 0;
2001
2002 c = *t;
2003 while (c == ' ' || c == '\t' )
2004 c = *++t;
2005 if (!c) {
2006 t = 0;
2007 return 0;
2008 }
2009 q = t;
2010 if (c == '\'') {
2011 c = *++t;
2012 q = t;
2013 while (c && c != '\'')
2014 c = *++t;
2015 if (!c) /* unterminated string */
2016 q = t = 0;
2017 else
2018 *t++ = 0;
2019 } else {
2020 while (c && c != ' ' && c != '\t' )
2021 c = *++t;
2022 *t++ = 0;
2023 if (!c)
2024 t = 0;
2025 }
2026 return q;
2027 }
2028
2029 #ifdef LOGIN_CAP
2030 static void
setprocresources(const char * cname)2031 setprocresources(const char *cname)
2032 {
2033 login_cap_t *lc;
2034 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
2035 setusercontext(lc, (struct passwd*)NULL, 0,
2036 LOGIN_SETENV |
2037 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
2038 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
2039 login_close(lc);
2040 }
2041 }
2042 #endif
2043
2044 /*
2045 * Run /etc/rc.final to execute scripts after all user processes have been
2046 * terminated.
2047 */
2048 static void
runfinal(void)2049 runfinal(void)
2050 {
2051 struct stat sb;
2052 pid_t other_pid, pid;
2053 sigset_t mask;
2054
2055 /* Avoid any surprises. */
2056 alarm(0);
2057
2058 /* rc.final is optional. */
2059 if (stat(_PATH_RUNFINAL, &sb) == -1 && errno == ENOENT)
2060 return;
2061 if (access(_PATH_RUNFINAL, X_OK) != 0) {
2062 warning("%s exists, but not executable", _PATH_RUNFINAL);
2063 return;
2064 }
2065
2066 pid = fork();
2067 if (pid == 0) {
2068 /*
2069 * Reopen stdin/stdout/stderr so that scripts can write to
2070 * console.
2071 */
2072 close(0);
2073 open(_PATH_DEVNULL, O_RDONLY);
2074 close(1);
2075 close(2);
2076 open_console();
2077 dup2(1, 2);
2078 sigemptyset(&mask);
2079 sigprocmask(SIG_SETMASK, &mask, NULL);
2080 signal(SIGCHLD, SIG_DFL);
2081 execl(_PATH_RUNFINAL, _PATH_RUNFINAL, NULL);
2082 perror("execl(" _PATH_RUNFINAL ") failed");
2083 exit(1);
2084 }
2085
2086 /* Wait for rc.final script to exit */
2087 while ((other_pid = waitpid(-1, NULL, 0)) != pid && other_pid > 0) {
2088 continue;
2089 }
2090 }
2091