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