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 static const char rcsid[] =
46 "$FreeBSD$";
47 #endif /* not lint */
48
49 #include <sys/param.h>
50 #include <sys/ioctl.h>
51 #include <sys/mman.h>
52 #include <sys/mount.h>
53 #include <sys/sysctl.h>
54 #include <sys/wait.h>
55 #include <sys/stat.h>
56 #include <sys/uio.h>
57
58 #include <db.h>
59 #include <errno.h>
60 #include <fcntl.h>
61 #include <kenv.h>
62 #include <libutil.h>
63 #include <paths.h>
64 #include <signal.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <syslog.h>
69 #include <time.h>
70 #include <ttyent.h>
71 #include <unistd.h>
72 #include <sys/reboot.h>
73 #include <err.h>
74
75 #include <stdarg.h>
76
77 #ifdef SECURE
78 #include <pwd.h>
79 #endif
80
81 #ifdef LOGIN_CAP
82 #include <login_cap.h>
83 #endif
84
85 #include "mntopts.h"
86 #include "pathnames.h"
87
88 /*
89 * Sleep times; used to prevent thrashing.
90 */
91 #define GETTY_SPACING 5 /* N secs minimum getty spacing */
92 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */
93 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */
94 #define WINDOW_WAIT 3 /* wait N secs after starting window */
95 #define STALL_TIMEOUT 30 /* wait N secs after warning */
96 #define DEATH_WATCH 10 /* wait N secs for procs to die */
97 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */
98 #define RESOURCE_RC "daemon"
99 #define RESOURCE_WINDOW "default"
100 #define RESOURCE_GETTY "default"
101
102 static void handle(sig_t, ...);
103 static void delset(sigset_t *, ...);
104
105 static void stall(const char *, ...) __printflike(1, 2);
106 static void warning(const char *, ...) __printflike(1, 2);
107 static void emergency(const char *, ...) __printflike(1, 2);
108 static void disaster(int);
109 static void revoke_ttys(void);
110 static int runshutdown(void);
111 static char *strk(char *);
112 static void runfinal(void);
113
114 /*
115 * We really need a recursive typedef...
116 * The following at least guarantees that the return type of (*state_t)()
117 * is sufficiently wide to hold a function pointer.
118 */
119 typedef long (*state_func_t)(void);
120 typedef state_func_t (*state_t)(void);
121
122 static state_func_t single_user(void);
123 static state_func_t runcom(void);
124 static state_func_t read_ttys(void);
125 static state_func_t multi_user(void);
126 static state_func_t clean_ttys(void);
127 static state_func_t catatonia(void);
128 static state_func_t death(void);
129 static state_func_t death_single(void);
130 static state_func_t reroot(void);
131 static state_func_t reroot_phase_two(void);
132
133 static state_func_t run_script(const char *);
134
135 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
136 #define FALSE 0
137 #define TRUE 1
138
139 static int Reboot = FALSE;
140 static int howto = RB_AUTOBOOT;
141
142 static int devfs;
143 static char *init_path_argv0;
144
145 static void transition(state_t);
146 static state_t requested_transition;
147 static state_t current_state = death_single;
148
149 static void execute_script(char *argv[]);
150 static void open_console(void);
151 static const char *get_shell(void);
152 static void replace_init(char *path);
153 static void write_stderr(const char *message);
154
155 typedef struct init_session {
156 pid_t se_process; /* controlling process */
157 time_t se_started; /* used to avoid thrashing */
158 int se_flags; /* status of session */
159 #define SE_SHUTDOWN 0x1 /* session won't be restarted */
160 #define SE_PRESENT 0x2 /* session is in /etc/ttys */
161 #define SE_IFEXISTS 0x4 /* session defined as "onifexists" */
162 #define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */
163 int se_nspace; /* spacing count */
164 char *se_device; /* filename of port */
165 char *se_getty; /* what to run on that port */
166 char *se_getty_argv_space; /* pre-parsed argument array space */
167 char **se_getty_argv; /* pre-parsed argument array */
168 char *se_window; /* window system (started only once) */
169 char *se_window_argv_space; /* pre-parsed argument array space */
170 char **se_window_argv; /* pre-parsed argument array */
171 char *se_type; /* default terminal type */
172 struct init_session *se_prev;
173 struct init_session *se_next;
174 } session_t;
175
176 static void free_session(session_t *);
177 static session_t *new_session(session_t *, struct ttyent *);
178 static session_t *sessions;
179
180 static char **construct_argv(char *);
181 static void start_window_system(session_t *);
182 static void collect_child(pid_t);
183 static pid_t start_getty(session_t *);
184 static void transition_handler(int);
185 static void alrm_handler(int);
186 static void setsecuritylevel(int);
187 static int getsecuritylevel(void);
188 static int setupargv(session_t *, struct ttyent *);
189 #ifdef LOGIN_CAP
190 static void setprocresources(const char *);
191 #endif
192 static int clang;
193
194 static int start_session_db(void);
195 static void add_session(session_t *);
196 static void del_session(session_t *);
197 static session_t *find_session(pid_t);
198 static DB *session_db;
199
200 /*
201 * The mother of all processes.
202 */
203 int
main(int argc,char * argv[])204 main(int argc, char *argv[])
205 {
206 state_t initial_transition = runcom;
207 char kenv_value[PATH_MAX];
208 int c, error;
209 struct sigaction sa;
210 sigset_t mask;
211
212 /* Dispose of random users. */
213 if (getuid() != 0)
214 errx(1, "%s", strerror(EPERM));
215
216 /* System V users like to reexec init. */
217 if (getpid() != 1) {
218 #ifdef COMPAT_SYSV_INIT
219 /* So give them what they want */
220 if (argc > 1) {
221 if (strlen(argv[1]) == 1) {
222 char runlevel = *argv[1];
223 int sig;
224
225 switch (runlevel) {
226 case '0': /* halt + poweroff */
227 sig = SIGUSR2;
228 break;
229 case '1': /* single-user */
230 sig = SIGTERM;
231 break;
232 case '6': /* reboot */
233 sig = SIGINT;
234 break;
235 case 'c': /* block further logins */
236 sig = SIGTSTP;
237 break;
238 case 'q': /* rescan /etc/ttys */
239 sig = SIGHUP;
240 break;
241 case 'r': /* remount root */
242 sig = SIGEMT;
243 break;
244 default:
245 goto invalid;
246 }
247 kill(1, sig);
248 _exit(0);
249 } else
250 invalid:
251 errx(1, "invalid run-level ``%s''", argv[1]);
252 } else
253 #endif
254 errx(1, "already running");
255 }
256
257 init_path_argv0 = strdup(argv[0]);
258 if (init_path_argv0 == NULL)
259 err(1, "strdup");
260
261 /*
262 * Note that this does NOT open a file...
263 * Does 'init' deserve its own facility number?
264 */
265 openlog("init", LOG_CONS, LOG_AUTH);
266
267 /*
268 * Create an initial session.
269 */
270 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1))
271 warning("initial setsid() failed: %m");
272
273 /*
274 * Establish an initial user so that programs running
275 * single user do not freak out and die (like passwd).
276 */
277 if (setlogin("root") < 0)
278 warning("setlogin() failed: %m");
279
280 /*
281 * This code assumes that we always get arguments through flags,
282 * never through bits set in some random machine register.
283 */
284 while ((c = getopt(argc, argv, "dsfr")) != -1)
285 switch (c) {
286 case 'd':
287 devfs = 1;
288 break;
289 case 's':
290 initial_transition = single_user;
291 break;
292 case 'f':
293 runcom_mode = FASTBOOT;
294 break;
295 case 'r':
296 initial_transition = reroot_phase_two;
297 break;
298 default:
299 warning("unrecognized flag '-%c'", c);
300 break;
301 }
302
303 if (optind != argc)
304 warning("ignoring excess arguments");
305
306 /*
307 * We catch or block signals rather than ignore them,
308 * so that they get reset on exec.
309 */
310 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
311 SIGXCPU, SIGXFSZ, 0);
312 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
313 SIGUSR1, SIGUSR2, SIGWINCH, 0);
314 handle(alrm_handler, SIGALRM, 0);
315 sigfillset(&mask);
316 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
317 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP,
318 SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0);
319 sigprocmask(SIG_SETMASK, &mask, NULL);
320 sigemptyset(&sa.sa_mask);
321 sa.sa_flags = 0;
322 sa.sa_handler = SIG_IGN;
323 sigaction(SIGTTIN, &sa, NULL);
324 sigaction(SIGTTOU, &sa, NULL);
325
326 /*
327 * Paranoia.
328 */
329 close(0);
330 close(1);
331 close(2);
332
333 if (kenv(KENV_GET, "init_exec", kenv_value, sizeof(kenv_value)) > 0) {
334 replace_init(kenv_value);
335 _exit(0); /* reboot */
336 }
337
338 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) {
339 state_func_t next_transition;
340
341 if ((next_transition = run_script(kenv_value)) != NULL)
342 initial_transition = (state_t) next_transition;
343 }
344
345 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) {
346 if (chdir(kenv_value) != 0 || chroot(".") != 0)
347 warning("Can't chroot to %s: %m", kenv_value);
348 }
349
350 /*
351 * Additional check if devfs needs to be mounted:
352 * If "/" and "/dev" have the same device number,
353 * then it hasn't been mounted yet.
354 */
355 if (!devfs) {
356 struct stat stst;
357 dev_t root_devno;
358
359 stat("/", &stst);
360 root_devno = stst.st_dev;
361 if (stat("/dev", &stst) != 0)
362 warning("Can't stat /dev: %m");
363 else if (stst.st_dev == root_devno)
364 devfs++;
365 }
366
367 if (devfs) {
368 struct iovec iov[4];
369 char *s;
370 int i;
371
372 char _fstype[] = "fstype";
373 char _devfs[] = "devfs";
374 char _fspath[] = "fspath";
375 char _path_dev[]= _PATH_DEV;
376
377 iov[0].iov_base = _fstype;
378 iov[0].iov_len = sizeof(_fstype);
379 iov[1].iov_base = _devfs;
380 iov[1].iov_len = sizeof(_devfs);
381 iov[2].iov_base = _fspath;
382 iov[2].iov_len = sizeof(_fspath);
383 /*
384 * Try to avoid the trailing slash in _PATH_DEV.
385 * Be *very* defensive.
386 */
387 s = strdup(_PATH_DEV);
388 if (s != NULL) {
389 i = strlen(s);
390 if (i > 0 && s[i - 1] == '/')
391 s[i - 1] = '\0';
392 iov[3].iov_base = s;
393 iov[3].iov_len = strlen(s) + 1;
394 } else {
395 iov[3].iov_base = _path_dev;
396 iov[3].iov_len = sizeof(_path_dev);
397 }
398 nmount(iov, 4, 0);
399 if (s != NULL)
400 free(s);
401 }
402
403 if (initial_transition != reroot_phase_two) {
404 /*
405 * Unmount reroot leftovers. This runs after init(8)
406 * gets reexecuted after reroot_phase_two() is done.
407 */
408 error = unmount(_PATH_REROOT, MNT_FORCE);
409 if (error != 0 && errno != EINVAL)
410 warning("Cannot unmount %s: %m", _PATH_REROOT);
411 }
412
413 /*
414 * Start the state machine.
415 */
416 transition(initial_transition);
417
418 /*
419 * Should never reach here.
420 */
421 return 1;
422 }
423
424 /*
425 * Associate a function with a signal handler.
426 */
427 static void
handle(sig_t handler,...)428 handle(sig_t handler, ...)
429 {
430 int sig;
431 struct sigaction sa;
432 sigset_t mask_everything;
433 va_list ap;
434 va_start(ap, handler);
435
436 sa.sa_handler = handler;
437 sigfillset(&mask_everything);
438
439 while ((sig = va_arg(ap, int)) != 0) {
440 sa.sa_mask = mask_everything;
441 /* XXX SA_RESTART? */
442 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
443 sigaction(sig, &sa, NULL);
444 }
445 va_end(ap);
446 }
447
448 /*
449 * Delete a set of signals from a mask.
450 */
451 static void
delset(sigset_t * maskp,...)452 delset(sigset_t *maskp, ...)
453 {
454 int sig;
455 va_list ap;
456 va_start(ap, maskp);
457
458 while ((sig = va_arg(ap, int)) != 0)
459 sigdelset(maskp, sig);
460 va_end(ap);
461 }
462
463 /*
464 * Log a message and sleep for a while (to give someone an opportunity
465 * to read it and to save log or hardcopy output if the problem is chronic).
466 * NB: should send a message to the session logger to avoid blocking.
467 */
468 static void
stall(const char * message,...)469 stall(const char *message, ...)
470 {
471 va_list ap;
472 va_start(ap, message);
473
474 vsyslog(LOG_ALERT, message, ap);
475 va_end(ap);
476 sleep(STALL_TIMEOUT);
477 }
478
479 /*
480 * Like stall(), but doesn't sleep.
481 * If cpp had variadic macros, the two functions could be #defines for another.
482 * NB: should send a message to the session logger to avoid blocking.
483 */
484 static void
warning(const char * message,...)485 warning(const char *message, ...)
486 {
487 va_list ap;
488 va_start(ap, message);
489
490 vsyslog(LOG_ALERT, message, ap);
491 va_end(ap);
492 }
493
494 /*
495 * Log an emergency message.
496 * NB: should send a message to the session logger to avoid blocking.
497 */
498 static void
emergency(const char * message,...)499 emergency(const char *message, ...)
500 {
501 va_list ap;
502 va_start(ap, message);
503
504 vsyslog(LOG_EMERG, message, ap);
505 va_end(ap);
506 }
507
508 /*
509 * Catch an unexpected signal.
510 */
511 static void
disaster(int sig)512 disaster(int sig)
513 {
514
515 emergency("fatal signal: %s",
516 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
517
518 sleep(STALL_TIMEOUT);
519 _exit(sig); /* reboot */
520 }
521
522 /*
523 * Get the security level of the kernel.
524 */
525 static int
getsecuritylevel(void)526 getsecuritylevel(void)
527 {
528 #ifdef KERN_SECURELVL
529 int name[2], curlevel;
530 size_t len;
531
532 name[0] = CTL_KERN;
533 name[1] = KERN_SECURELVL;
534 len = sizeof curlevel;
535 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
536 emergency("cannot get kernel security level: %m");
537 return (-1);
538 }
539 return (curlevel);
540 #else
541 return (-1);
542 #endif
543 }
544
545 /*
546 * Set the security level of the kernel.
547 */
548 static void
setsecuritylevel(int newlevel)549 setsecuritylevel(int newlevel)
550 {
551 #ifdef KERN_SECURELVL
552 int name[2], curlevel;
553
554 curlevel = getsecuritylevel();
555 if (newlevel == curlevel)
556 return;
557 name[0] = CTL_KERN;
558 name[1] = KERN_SECURELVL;
559 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
560 emergency(
561 "cannot change kernel security level from %d to %d: %m",
562 curlevel, newlevel);
563 return;
564 }
565 #ifdef SECURE
566 warning("kernel security level changed from %d to %d",
567 curlevel, newlevel);
568 #endif
569 #endif
570 }
571
572 /*
573 * Change states in the finite state machine.
574 * The initial state is passed as an argument.
575 */
576 static void
transition(state_t s)577 transition(state_t s)
578 {
579
580 current_state = s;
581 for (;;)
582 current_state = (state_t) (*current_state)();
583 }
584
585 /*
586 * Start a session and allocate a controlling terminal.
587 * Only called by children of init after forking.
588 */
589 static void
open_console(void)590 open_console(void)
591 {
592 int fd;
593
594 /*
595 * Try to open /dev/console. Open the device with O_NONBLOCK to
596 * prevent potential blocking on a carrier.
597 */
598 revoke(_PATH_CONSOLE);
599 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) {
600 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
601 if (login_tty(fd) == 0)
602 return;
603 close(fd);
604 }
605
606 /* No luck. Log output to file if possible. */
607 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
608 stall("cannot open null device.");
609 _exit(1);
610 }
611 if (fd != STDIN_FILENO) {
612 dup2(fd, STDIN_FILENO);
613 close(fd);
614 }
615 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644);
616 if (fd == -1)
617 dup2(STDIN_FILENO, STDOUT_FILENO);
618 else if (fd != STDOUT_FILENO) {
619 dup2(fd, STDOUT_FILENO);
620 close(fd);
621 }
622 dup2(STDOUT_FILENO, STDERR_FILENO);
623 }
624
625 static const char *
get_shell(void)626 get_shell(void)
627 {
628 static char kenv_value[PATH_MAX];
629
630 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0)
631 return kenv_value;
632 else
633 return _PATH_BSHELL;
634 }
635
636 static void
write_stderr(const char * message)637 write_stderr(const char *message)
638 {
639
640 write(STDERR_FILENO, message, strlen(message));
641 }
642
643 static int
read_file(const char * path,void ** bufp,size_t * bufsizep)644 read_file(const char *path, void **bufp, size_t *bufsizep)
645 {
646 struct stat sb;
647 size_t bufsize;
648 void *buf;
649 ssize_t nbytes;
650 int error, fd;
651
652 fd = open(path, O_RDONLY);
653 if (fd < 0) {
654 emergency("%s: %m", path);
655 return (-1);
656 }
657
658 error = fstat(fd, &sb);
659 if (error != 0) {
660 emergency("fstat: %m");
661 close(fd);
662 return (error);
663 }
664
665 bufsize = sb.st_size;
666 buf = malloc(bufsize);
667 if (buf == NULL) {
668 emergency("malloc: %m");
669 close(fd);
670 return (error);
671 }
672
673 nbytes = read(fd, buf, bufsize);
674 if (nbytes != (ssize_t)bufsize) {
675 emergency("read: %m");
676 close(fd);
677 free(buf);
678 return (error);
679 }
680
681 error = close(fd);
682 if (error != 0) {
683 emergency("close: %m");
684 free(buf);
685 return (error);
686 }
687
688 *bufp = buf;
689 *bufsizep = bufsize;
690
691 return (0);
692 }
693
694 static int
create_file(const char * path,const void * buf,size_t bufsize)695 create_file(const char *path, const void *buf, size_t bufsize)
696 {
697 ssize_t nbytes;
698 int error, fd;
699
700 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700);
701 if (fd < 0) {
702 emergency("%s: %m", path);
703 return (-1);
704 }
705
706 nbytes = write(fd, buf, bufsize);
707 if (nbytes != (ssize_t)bufsize) {
708 emergency("write: %m");
709 close(fd);
710 return (-1);
711 }
712
713 error = close(fd);
714 if (error != 0) {
715 emergency("close: %m");
716 return (-1);
717 }
718
719 return (0);
720 }
721
722 static int
mount_tmpfs(const char * fspath)723 mount_tmpfs(const char *fspath)
724 {
725 struct iovec *iov;
726 char errmsg[255];
727 int error, iovlen;
728
729 iov = NULL;
730 iovlen = 0;
731 memset(errmsg, 0, sizeof(errmsg));
732 build_iovec(&iov, &iovlen, "fstype",
733 __DECONST(void *, "tmpfs"), (size_t)-1);
734 build_iovec(&iov, &iovlen, "fspath",
735 __DECONST(void *, fspath), (size_t)-1);
736 build_iovec(&iov, &iovlen, "errmsg",
737 errmsg, sizeof(errmsg));
738
739 error = nmount(iov, iovlen, 0);
740 if (error != 0) {
741 if (*errmsg != '\0') {
742 emergency("cannot mount tmpfs on %s: %s: %m",
743 fspath, errmsg);
744 } else {
745 emergency("cannot mount tmpfs on %s: %m",
746 fspath);
747 }
748 return (error);
749 }
750 return (0);
751 }
752
753 static state_func_t
reroot(void)754 reroot(void)
755 {
756 void *buf;
757 size_t bufsize;
758 int error;
759
760 buf = NULL;
761 bufsize = 0;
762
763 revoke_ttys();
764 runshutdown();
765
766 /*
767 * Make sure nobody can interfere with our scheme.
768 * Ignore ESRCH, which can apparently happen when
769 * there are no processes to kill.
770 */
771 error = kill(-1, SIGKILL);
772 if (error != 0 && errno != ESRCH) {
773 emergency("kill(2) failed: %m");
774 goto out;
775 }
776
777 /*
778 * Copy the init binary into tmpfs, so that we can unmount
779 * the old rootfs without committing suicide.
780 */
781 error = read_file(init_path_argv0, &buf, &bufsize);
782 if (error != 0)
783 goto out;
784 error = mount_tmpfs(_PATH_REROOT);
785 if (error != 0)
786 goto out;
787 error = create_file(_PATH_REROOT_INIT, buf, bufsize);
788 if (error != 0)
789 goto out;
790
791 /*
792 * Execute the temporary init.
793 */
794 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL);
795 emergency("cannot exec %s: %m", _PATH_REROOT_INIT);
796
797 out:
798 emergency("reroot failed; going to single user mode");
799 free(buf);
800 return (state_func_t) single_user;
801 }
802
803 static state_func_t
reroot_phase_two(void)804 reroot_phase_two(void)
805 {
806 char init_path[PATH_MAX], *path, *path_component;
807 size_t init_path_len;
808 int nbytes, error;
809
810 /*
811 * Ask the kernel to mount the new rootfs.
812 */
813 error = reboot(RB_REROOT);
814 if (error != 0) {
815 emergency("RB_REBOOT failed: %m");
816 goto out;
817 }
818
819 /*
820 * Figure out where the destination init(8) binary is. Note that
821 * the path could be different than what we've started with. Use
822 * the value from kenv, if set, or the one from sysctl otherwise.
823 * The latter defaults to a hardcoded value, but can be overridden
824 * by a build time option.
825 */
826 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path));
827 if (nbytes <= 0) {
828 init_path_len = sizeof(init_path);
829 error = sysctlbyname("kern.init_path",
830 init_path, &init_path_len, NULL, 0);
831 if (error != 0) {
832 emergency("failed to retrieve kern.init_path: %m");
833 goto out;
834 }
835 }
836
837 /*
838 * Repeat the init search logic from sys/kern/init_path.c
839 */
840 path_component = init_path;
841 while ((path = strsep(&path_component, ":")) != NULL) {
842 /*
843 * Execute init(8) from the new rootfs.
844 */
845 execl(path, path, NULL);
846 }
847 emergency("cannot exec init from %s: %m", init_path);
848
849 out:
850 emergency("reroot failed; going to single user mode");
851 return (state_func_t) single_user;
852 }
853
854 /*
855 * Bring the system up single user.
856 */
857 static state_func_t
single_user(void)858 single_user(void)
859 {
860 pid_t pid, wpid;
861 int status;
862 sigset_t mask;
863 const char *shell;
864 char *argv[2];
865 struct timeval tv, tn;
866 #ifdef SECURE
867 struct ttyent *typ;
868 struct passwd *pp;
869 static const char banner[] =
870 "Enter root password, or ^D to go multi-user\n";
871 char *clear, *password;
872 #endif
873 #ifdef DEBUGSHELL
874 char altshell[128];
875 #endif
876
877 if (Reboot) {
878 /* Instead of going single user, let's reboot the machine */
879 sync();
880 /* Run scripts after all processes have been terminated. */
881 runfinal();
882 if (reboot(howto) == -1) {
883 emergency("reboot(%#x) failed, %m", howto);
884 _exit(1); /* panic and reboot */
885 }
886 warning("reboot(%#x) returned", howto);
887 _exit(0); /* panic as well */
888 }
889
890 shell = get_shell();
891
892 if ((pid = fork()) == 0) {
893 /*
894 * Start the single user session.
895 */
896 open_console();
897
898 #ifdef SECURE
899 /*
900 * Check the root password.
901 * We don't care if the console is 'on' by default;
902 * it's the only tty that can be 'off' and 'secure'.
903 */
904 typ = getttynam("console");
905 pp = getpwnam("root");
906 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
907 pp && *pp->pw_passwd) {
908 write_stderr(banner);
909 for (;;) {
910 clear = getpass("Password:");
911 if (clear == NULL || *clear == '\0')
912 _exit(0);
913 password = crypt(clear, pp->pw_passwd);
914 explicit_bzero(clear, _PASSWORD_LEN);
915 if (password != NULL &&
916 strcmp(password, pp->pw_passwd) == 0)
917 break;
918 warning("single-user login failed\n");
919 }
920 }
921 endttyent();
922 endpwent();
923 #endif /* SECURE */
924
925 #ifdef DEBUGSHELL
926 {
927 char *cp = altshell;
928 int num;
929
930 #define SHREQUEST "Enter full pathname of shell or RETURN for "
931 write_stderr(SHREQUEST);
932 write_stderr(shell);
933 write_stderr(": ");
934 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
935 num != 0 && *cp != '\n' && cp < &altshell[127])
936 cp++;
937 *cp = '\0';
938 if (altshell[0] != '\0')
939 shell = altshell;
940 }
941 #endif /* DEBUGSHELL */
942
943 /*
944 * Unblock signals.
945 * We catch all the interesting ones,
946 * and those are reset to SIG_DFL on exec.
947 */
948 sigemptyset(&mask);
949 sigprocmask(SIG_SETMASK, &mask, NULL);
950
951 /*
952 * Fire off a shell.
953 * If the default one doesn't work, try the Bourne shell.
954 */
955
956 char name[] = "-sh";
957
958 argv[0] = name;
959 argv[1] = NULL;
960 execv(shell, argv);
961 emergency("can't exec %s for single user: %m", shell);
962 execv(_PATH_BSHELL, argv);
963 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
964 sleep(STALL_TIMEOUT);
965 _exit(1);
966 }
967
968 if (pid == -1) {
969 /*
970 * We are seriously hosed. Do our best.
971 */
972 emergency("can't fork single-user shell, trying again");
973 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
974 continue;
975 return (state_func_t) single_user;
976 }
977
978 requested_transition = 0;
979 do {
980 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
981 collect_child(wpid);
982 if (wpid == -1) {
983 if (errno == EINTR)
984 continue;
985 warning("wait for single-user shell failed: %m; restarting");
986 return (state_func_t) single_user;
987 }
988 if (wpid == pid && WIFSTOPPED(status)) {
989 warning("init: shell stopped, restarting\n");
990 kill(pid, SIGCONT);
991 wpid = -1;
992 }
993 } while (wpid != pid && !requested_transition);
994
995 if (requested_transition)
996 return (state_func_t) requested_transition;
997
998 if (!WIFEXITED(status)) {
999 if (WTERMSIG(status) == SIGKILL) {
1000 /*
1001 * reboot(8) killed shell?
1002 */
1003 warning("single user shell terminated.");
1004 gettimeofday(&tv, NULL);
1005 tn = tv;
1006 tv.tv_sec += STALL_TIMEOUT;
1007 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec ==
1008 tn.tv_sec && tv.tv_usec > tn.tv_usec)) {
1009 sleep(1);
1010 gettimeofday(&tn, NULL);
1011 }
1012 _exit(0);
1013 } else {
1014 warning("single user shell terminated, restarting");
1015 return (state_func_t) single_user;
1016 }
1017 }
1018
1019 runcom_mode = FASTBOOT;
1020 return (state_func_t) runcom;
1021 }
1022
1023 /*
1024 * Run the system startup script.
1025 */
1026 static state_func_t
runcom(void)1027 runcom(void)
1028 {
1029 state_func_t next_transition;
1030
1031 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL)
1032 return next_transition;
1033
1034 runcom_mode = AUTOBOOT; /* the default */
1035 return (state_func_t) read_ttys;
1036 }
1037
1038 static void
execute_script(char * argv[])1039 execute_script(char *argv[])
1040 {
1041 struct sigaction sa;
1042 const char *shell, *script;
1043 int error;
1044
1045 bzero(&sa, sizeof(sa));
1046 sigemptyset(&sa.sa_mask);
1047 sa.sa_handler = SIG_IGN;
1048 sigaction(SIGTSTP, &sa, NULL);
1049 sigaction(SIGHUP, &sa, NULL);
1050
1051 open_console();
1052
1053 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1054 #ifdef LOGIN_CAP
1055 setprocresources(RESOURCE_RC);
1056 #endif
1057
1058 /*
1059 * Try to directly execute the script first. If it
1060 * fails, try the old method of passing the script path
1061 * to sh(1). Don't complain if it fails because of
1062 * the missing execute bit.
1063 */
1064 script = argv[1];
1065 error = access(script, X_OK);
1066 if (error == 0) {
1067 execv(script, argv + 1);
1068 warning("can't directly exec %s: %m", script);
1069 } else if (errno != EACCES) {
1070 warning("can't access %s: %m", script);
1071 }
1072
1073 shell = get_shell();
1074 execv(shell, argv);
1075 stall("can't exec %s for %s: %m", shell, script);
1076 }
1077
1078 /*
1079 * Execute binary, replacing init(8) as PID 1.
1080 */
1081 static void
replace_init(char * path)1082 replace_init(char *path)
1083 {
1084 char *argv[3];
1085 char sh[] = "sh";
1086
1087 argv[0] = sh;
1088 argv[1] = path;
1089 argv[2] = NULL;
1090
1091 execute_script(argv);
1092 }
1093
1094 /*
1095 * Run a shell script.
1096 * Returns 0 on success, otherwise the next transition to enter:
1097 * - single_user if fork/execv/waitpid failed, or if the script
1098 * terminated with a signal or exit code != 0.
1099 * - death_single if a SIGTERM was delivered to init(8).
1100 */
1101 static state_func_t
run_script(const char * script)1102 run_script(const char *script)
1103 {
1104 pid_t pid, wpid;
1105 int status;
1106 char *argv[4];
1107 const char *shell;
1108
1109 shell = get_shell();
1110
1111 if ((pid = fork()) == 0) {
1112
1113 char _sh[] = "sh";
1114 char _autoboot[] = "autoboot";
1115
1116 argv[0] = _sh;
1117 argv[1] = __DECONST(char *, script);
1118 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0;
1119 argv[3] = 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 (wpid == -1) {
1142 if (requested_transition == death_single ||
1143 requested_transition == reroot)
1144 return (state_func_t) requested_transition;
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 /*
1602 * Catch a signal and request a state transition.
1603 */
1604 static void
transition_handler(int sig)1605 transition_handler(int sig)
1606 {
1607
1608 switch (sig) {
1609 case SIGHUP:
1610 if (current_state == read_ttys || current_state == multi_user ||
1611 current_state == clean_ttys || current_state == catatonia)
1612 requested_transition = clean_ttys;
1613 break;
1614 case SIGUSR2:
1615 howto = RB_POWEROFF;
1616 case SIGUSR1:
1617 howto |= RB_HALT;
1618 case SIGWINCH:
1619 case SIGINT:
1620 if (sig == SIGWINCH)
1621 howto |= RB_POWERCYCLE;
1622 Reboot = TRUE;
1623 case SIGTERM:
1624 if (current_state == read_ttys || current_state == multi_user ||
1625 current_state == clean_ttys || current_state == catatonia)
1626 requested_transition = death;
1627 else
1628 requested_transition = death_single;
1629 break;
1630 case SIGTSTP:
1631 if (current_state == runcom || current_state == read_ttys ||
1632 current_state == clean_ttys ||
1633 current_state == multi_user || current_state == catatonia)
1634 requested_transition = catatonia;
1635 break;
1636 case SIGEMT:
1637 requested_transition = reroot;
1638 break;
1639 default:
1640 requested_transition = 0;
1641 break;
1642 }
1643 }
1644
1645 /*
1646 * Take the system multiuser.
1647 */
1648 static state_func_t
multi_user(void)1649 multi_user(void)
1650 {
1651 pid_t pid;
1652 session_t *sp;
1653
1654 requested_transition = 0;
1655
1656 /*
1657 * If the administrator has not set the security level to -1
1658 * to indicate that the kernel should not run multiuser in secure
1659 * mode, and the run script has not set a higher level of security
1660 * than level 1, then put the kernel into secure mode.
1661 */
1662 if (getsecuritylevel() == 0)
1663 setsecuritylevel(1);
1664
1665 for (sp = sessions; sp; sp = sp->se_next) {
1666 if (sp->se_process)
1667 continue;
1668 if (session_has_no_tty(sp))
1669 continue;
1670 if ((pid = start_getty(sp)) == -1) {
1671 /* serious trouble */
1672 requested_transition = clean_ttys;
1673 break;
1674 }
1675 sp->se_process = pid;
1676 sp->se_started = time((time_t *) 0);
1677 add_session(sp);
1678 }
1679
1680 while (!requested_transition)
1681 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1682 collect_child(pid);
1683
1684 return (state_func_t) requested_transition;
1685 }
1686
1687 /*
1688 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often...
1689 */
1690 static state_func_t
clean_ttys(void)1691 clean_ttys(void)
1692 {
1693 session_t *sp, *sprev;
1694 struct ttyent *typ;
1695 int devlen;
1696 char *old_getty, *old_window, *old_type;
1697
1698 /*
1699 * mark all sessions for death, (!SE_PRESENT)
1700 * as we find or create new ones they'll be marked as keepers,
1701 * we'll later nuke all the ones not found in /etc/ttys
1702 */
1703 for (sp = sessions; sp != NULL; sp = sp->se_next)
1704 sp->se_flags &= ~SE_PRESENT;
1705
1706 devlen = sizeof(_PATH_DEV) - 1;
1707 while ((typ = getttyent()) != NULL) {
1708 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1709 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1710 break;
1711
1712 if (sp) {
1713 /* we want this one to live */
1714 sp->se_flags |= SE_PRESENT;
1715 if ((typ->ty_status & TTY_ON) == 0 ||
1716 typ->ty_getty == 0) {
1717 sp->se_flags |= SE_SHUTDOWN;
1718 kill(sp->se_process, SIGHUP);
1719 continue;
1720 }
1721 sp->se_flags &= ~SE_SHUTDOWN;
1722 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1723 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1724 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1725 if (setupargv(sp, typ) == 0) {
1726 warning("can't parse getty for port %s",
1727 sp->se_device);
1728 sp->se_flags |= SE_SHUTDOWN;
1729 kill(sp->se_process, SIGHUP);
1730 }
1731 else if ( !old_getty
1732 || (!old_type && sp->se_type)
1733 || (old_type && !sp->se_type)
1734 || (!old_window && sp->se_window)
1735 || (old_window && !sp->se_window)
1736 || (strcmp(old_getty, sp->se_getty) != 0)
1737 || (old_window && strcmp(old_window, sp->se_window) != 0)
1738 || (old_type && strcmp(old_type, sp->se_type) != 0)
1739 ) {
1740 /* Don't set SE_SHUTDOWN here */
1741 sp->se_nspace = 0;
1742 sp->se_started = 0;
1743 kill(sp->se_process, SIGHUP);
1744 }
1745 if (old_getty)
1746 free(old_getty);
1747 if (old_window)
1748 free(old_window);
1749 if (old_type)
1750 free(old_type);
1751 continue;
1752 }
1753
1754 new_session(sprev, typ);
1755 }
1756
1757 endttyent();
1758
1759 /*
1760 * sweep through and kill all deleted sessions
1761 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1762 */
1763 for (sp = sessions; sp != NULL; sp = sp->se_next) {
1764 if ((sp->se_flags & SE_PRESENT) == 0) {
1765 sp->se_flags |= SE_SHUTDOWN;
1766 kill(sp->se_process, SIGHUP);
1767 }
1768 }
1769
1770 return (state_func_t) multi_user;
1771 }
1772
1773 /*
1774 * Block further logins.
1775 */
1776 static state_func_t
catatonia(void)1777 catatonia(void)
1778 {
1779 session_t *sp;
1780
1781 for (sp = sessions; sp; sp = sp->se_next)
1782 sp->se_flags |= SE_SHUTDOWN;
1783
1784 return (state_func_t) multi_user;
1785 }
1786
1787 /*
1788 * Note SIGALRM.
1789 */
1790 static void
alrm_handler(int sig)1791 alrm_handler(int sig)
1792 {
1793
1794 (void)sig;
1795 clang = 1;
1796 }
1797
1798 /*
1799 * Bring the system down to single user.
1800 */
1801 static state_func_t
death(void)1802 death(void)
1803 {
1804 int block, blocked;
1805 size_t len;
1806
1807 /* Temporarily block suspend. */
1808 len = sizeof(blocked);
1809 block = 1;
1810 if (sysctlbyname("kern.suspend_blocked", &blocked, &len,
1811 &block, sizeof(block)) == -1)
1812 blocked = 0;
1813
1814 /*
1815 * Also revoke the TTY here. Because runshutdown() may reopen
1816 * the TTY whose getty we're killing here, there is no guarantee
1817 * runshutdown() will perform the initial open() call, causing
1818 * the terminal attributes to be misconfigured.
1819 */
1820 revoke_ttys();
1821
1822 /* Try to run the rc.shutdown script within a period of time */
1823 runshutdown();
1824
1825 /* Unblock suspend if we blocked it. */
1826 if (!blocked)
1827 sysctlbyname("kern.suspend_blocked", NULL, NULL,
1828 &blocked, sizeof(blocked));
1829
1830 return (state_func_t) death_single;
1831 }
1832
1833 /*
1834 * Do what is necessary to reinitialize single user mode or reboot
1835 * from an incomplete state.
1836 */
1837 static state_func_t
death_single(void)1838 death_single(void)
1839 {
1840 int i;
1841 pid_t pid;
1842 static const int death_sigs[2] = { SIGTERM, SIGKILL };
1843
1844 revoke(_PATH_CONSOLE);
1845
1846 for (i = 0; i < 2; ++i) {
1847 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1848 return (state_func_t) single_user;
1849
1850 clang = 0;
1851 alarm(DEATH_WATCH);
1852 do
1853 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1854 collect_child(pid);
1855 while (clang == 0 && errno != ECHILD);
1856
1857 if (errno == ECHILD)
1858 return (state_func_t) single_user;
1859 }
1860
1861 warning("some processes would not die; ps axl advised");
1862
1863 return (state_func_t) single_user;
1864 }
1865
1866 static void
revoke_ttys(void)1867 revoke_ttys(void)
1868 {
1869 session_t *sp;
1870
1871 for (sp = sessions; sp; sp = sp->se_next) {
1872 sp->se_flags |= SE_SHUTDOWN;
1873 kill(sp->se_process, SIGHUP);
1874 revoke(sp->se_device);
1875 }
1876 }
1877
1878 /*
1879 * Run the system shutdown script.
1880 *
1881 * Exit codes: XXX I should document more
1882 * -2 shutdown script terminated abnormally
1883 * -1 fatal error - can't run script
1884 * 0 good.
1885 * >0 some error (exit code)
1886 */
1887 static int
runshutdown(void)1888 runshutdown(void)
1889 {
1890 pid_t pid, wpid;
1891 int status;
1892 int shutdowntimeout;
1893 size_t len;
1894 char *argv[4];
1895 struct stat sb;
1896
1897 /*
1898 * rc.shutdown is optional, so to prevent any unnecessary
1899 * complaints from the shell we simply don't run it if the
1900 * file does not exist. If the stat() here fails for other
1901 * reasons, we'll let the shell complain.
1902 */
1903 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1904 return 0;
1905
1906 if ((pid = fork()) == 0) {
1907 char _sh[] = "sh";
1908 char _reboot[] = "reboot";
1909 char _single[] = "single";
1910 char _path_rundown[] = _PATH_RUNDOWN;
1911
1912 argv[0] = _sh;
1913 argv[1] = _path_rundown;
1914 argv[2] = Reboot ? _reboot : _single;
1915 argv[3] = NULL;
1916
1917 execute_script(argv);
1918 _exit(1); /* force single user mode */
1919 }
1920
1921 if (pid == -1) {
1922 emergency("can't fork for %s: %m", _PATH_RUNDOWN);
1923 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
1924 continue;
1925 sleep(STALL_TIMEOUT);
1926 return -1;
1927 }
1928
1929 len = sizeof(shutdowntimeout);
1930 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len,
1931 NULL, 0) == -1 || shutdowntimeout < 2)
1932 shutdowntimeout = DEATH_SCRIPT;
1933 alarm(shutdowntimeout);
1934 clang = 0;
1935 /*
1936 * Copied from single_user(). This is a bit paranoid.
1937 * Use the same ALRM handler.
1938 */
1939 do {
1940 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1941 collect_child(wpid);
1942 if (clang == 1) {
1943 /* we were waiting for the sub-shell */
1944 kill(wpid, SIGTERM);
1945 warning("timeout expired for %s: %m; going to "
1946 "single user mode", _PATH_RUNDOWN);
1947 return -1;
1948 }
1949 if (wpid == -1) {
1950 if (errno == EINTR)
1951 continue;
1952 warning("wait for %s failed: %m; going to "
1953 "single user mode", _PATH_RUNDOWN);
1954 return -1;
1955 }
1956 if (wpid == pid && WIFSTOPPED(status)) {
1957 warning("init: %s stopped, restarting\n",
1958 _PATH_RUNDOWN);
1959 kill(pid, SIGCONT);
1960 wpid = -1;
1961 }
1962 } while (wpid != pid && !clang);
1963
1964 /* Turn off the alarm */
1965 alarm(0);
1966
1967 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1968 requested_transition == catatonia) {
1969 /*
1970 * /etc/rc.shutdown executed /sbin/reboot;
1971 * wait for the end quietly
1972 */
1973 sigset_t s;
1974
1975 sigfillset(&s);
1976 for (;;)
1977 sigsuspend(&s);
1978 }
1979
1980 if (!WIFEXITED(status)) {
1981 warning("%s terminated abnormally, going to "
1982 "single user mode", _PATH_RUNDOWN);
1983 return -2;
1984 }
1985
1986 if ((status = WEXITSTATUS(status)) != 0)
1987 warning("%s returned status %d", _PATH_RUNDOWN, status);
1988
1989 return status;
1990 }
1991
1992 static char *
strk(char * p)1993 strk(char *p)
1994 {
1995 static char *t;
1996 char *q;
1997 int c;
1998
1999 if (p)
2000 t = p;
2001 if (!t)
2002 return 0;
2003
2004 c = *t;
2005 while (c == ' ' || c == '\t' )
2006 c = *++t;
2007 if (!c) {
2008 t = 0;
2009 return 0;
2010 }
2011 q = t;
2012 if (c == '\'') {
2013 c = *++t;
2014 q = t;
2015 while (c && c != '\'')
2016 c = *++t;
2017 if (!c) /* unterminated string */
2018 q = t = 0;
2019 else
2020 *t++ = 0;
2021 } else {
2022 while (c && c != ' ' && c != '\t' )
2023 c = *++t;
2024 *t++ = 0;
2025 if (!c)
2026 t = 0;
2027 }
2028 return q;
2029 }
2030
2031 #ifdef LOGIN_CAP
2032 static void
setprocresources(const char * cname)2033 setprocresources(const char *cname)
2034 {
2035 login_cap_t *lc;
2036 if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
2037 setusercontext(lc, (struct passwd*)NULL, 0,
2038 LOGIN_SETENV |
2039 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
2040 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK);
2041 login_close(lc);
2042 }
2043 }
2044 #endif
2045
2046 /*
2047 * Run /etc/rc.final to execute scripts after all user processes have been
2048 * terminated.
2049 */
2050 static void
runfinal(void)2051 runfinal(void)
2052 {
2053 struct stat sb;
2054 pid_t other_pid, pid;
2055 sigset_t mask;
2056
2057 /* Avoid any surprises. */
2058 alarm(0);
2059
2060 /* rc.final is optional. */
2061 if (stat(_PATH_RUNFINAL, &sb) == -1 && errno == ENOENT)
2062 return;
2063 if (access(_PATH_RUNFINAL, X_OK) != 0) {
2064 warning("%s exists, but not executable", _PATH_RUNFINAL);
2065 return;
2066 }
2067
2068 pid = fork();
2069 if (pid == 0) {
2070 /*
2071 * Reopen stdin/stdout/stderr so that scripts can write to
2072 * console.
2073 */
2074 close(0);
2075 open(_PATH_DEVNULL, O_RDONLY);
2076 close(1);
2077 close(2);
2078 open_console();
2079 dup2(1, 2);
2080 sigemptyset(&mask);
2081 sigprocmask(SIG_SETMASK, &mask, NULL);
2082 signal(SIGCHLD, SIG_DFL);
2083 execl(_PATH_RUNFINAL, _PATH_RUNFINAL, NULL);
2084 perror("execl(" _PATH_RUNFINAL ") failed");
2085 exit(1);
2086 }
2087
2088 /* Wait for rc.final script to exit */
2089 while ((other_pid = waitpid(-1, NULL, 0)) != pid && other_pid > 0) {
2090 continue;
2091 }
2092 }
2093