1/*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Donn Seeley at Berkeley Software Design, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38static char copyright[] =
39"@(#) Copyright (c) 1991, 1993\n\
40 The Regents of the University of California. All rights reserved.\n";
41#endif /* not lint */
42
43#ifndef lint
44static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93";
45#endif /* not lint */
46
47#include <sys/param.h>
48#include <sys/mount.h>
49#include <sys/sysctl.h>
50#include <sys/wait.h>
51
52#include <db.h>
53#include <errno.h>
54#include <fcntl.h>
55#include <signal.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <syslog.h>
60#include <time.h>
61#include <ttyent.h>
62#include <unistd.h>
63#include <sys/reboot.h>
64
65#ifdef __STDC__
66#include <stdarg.h>
67#else
68#include <varargs.h>
69#endif
70
71#ifdef SECURE
72#include <pwd.h>
73#endif
74
75#ifdef LOGIN_CAP
76#include <login_cap.h>
77#endif
78
79#include "pathnames.h"
80
81/*
82 * Until the mythical util.h arrives...
83 */
84extern int login_tty __P((int));
85extern int logout __P((const char *));
86extern void logwtmp __P((const char *, const char *, const char *));
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 RESOURCE_RC "daemon"
98#define RESOURCE_WINDOW "default"
99#define RESOURCE_GETTY "default"
100
101void handle __P((sig_t, ...));
102void delset __P((sigset_t *, ...));
103
104void stall __P((char *, ...));
105void warning __P((char *, ...));
106void emergency __P((char *, ...));
107void disaster __P((int));
108void badsys __P((int));
109
110/*
111 * We really need a recursive typedef...
112 * The following at least guarantees that the return type of (*state_t)()
113 * is sufficiently wide to hold a function pointer.
114 */
115typedef long (*state_func_t) __P((void));
116typedef state_func_t (*state_t) __P((void));
117
118state_func_t single_user __P((void));
119state_func_t runcom __P((void));
120state_func_t read_ttys __P((void));
121state_func_t multi_user __P((void));
122state_func_t clean_ttys __P((void));
123state_func_t catatonia __P((void));
124state_func_t death __P((void));
125
126enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
127#define FALSE 0
128#define TRUE 1
129
130int Reboot = FALSE;
131
132int devfs;
133
134void transition __P((state_t));
135state_t requested_transition = runcom;
136
137void setctty __P((char *));
138
139typedef struct init_session {
140 int se_index; /* index of entry in ttys file */
141 pid_t se_process; /* controlling process */
142 time_t se_started; /* used to avoid thrashing */
143 int se_flags; /* status of session */
144#define SE_SHUTDOWN 0x1 /* session won't be restarted */
145 int se_nspace; /* spacing count */
146 char *se_device; /* filename of port */
147 char *se_getty; /* what to run on that port */
148 char *se_getty_argv_space; /* pre-parsed argument array space */
149 char **se_getty_argv; /* pre-parsed argument array */
150 char *se_window; /* window system (started only once) */
151 char *se_window_argv_space; /* pre-parsed argument array space */
152 char **se_window_argv; /* pre-parsed argument array */
153 char *se_type; /* default terminal type */
154 struct init_session *se_prev;
155 struct init_session *se_next;
156} session_t;
157
158void free_session __P((session_t *));
159session_t *new_session __P((session_t *, int, struct ttyent *));
160session_t *sessions;
161
162char **construct_argv __P((char *));
163void start_window_system __P((session_t *));
164void collect_child __P((pid_t));
165pid_t start_getty __P((session_t *));
166void transition_handler __P((int));
167void alrm_handler __P((int));
168void setsecuritylevel __P((int));
169int getsecuritylevel __P((void));
170int setupargv __P((session_t *, struct ttyent *));
171#ifdef LOGIN_CAP
172void setprocresources __P((const char *));
173#endif
174int clang;
175
176void clear_session_logs __P((session_t *));
177
178int start_session_db __P((void));
179void add_session __P((session_t *));
180void del_session __P((session_t *));
181session_t *find_session __P((pid_t));
182DB *session_db;
183
184/*
185 * The mother of all processes.
186 */
187int
188main(argc, argv)
189 int argc;
190 char **argv;
191{
192 int c;
193 struct sigaction sa;
194 sigset_t mask;
195
196
197 /* Dispose of random users. */
198 if (getuid() != 0) {
199 (void)fprintf(stderr, "init: %s\n", strerror(EPERM));
200 exit (1);
201 }
202
203 /* System V users like to reexec init. */
204 if (getpid() != 1) {
205 (void)fprintf(stderr, "init: already running\n");
206 exit (1);
207 }
208
209 /*
210 * Note that this does NOT open a file...
211 * Does 'init' deserve its own facility number?
212 */
213 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
214
215 /*
216 * Create an initial session.
217 */
218 if (setsid() < 0)
219 warning("initial setsid() failed: %m");
220
221 /*
222 * Establish an initial user so that programs running
223 * single user do not freak out and die (like passwd).
224 */
225 if (setlogin("root") < 0)
226 warning("setlogin() failed: %m");
227
228 /*
229 * This code assumes that we always get arguments through flags,
230 * never through bits set in some random machine register.
231 */
232 while ((c = getopt(argc, argv, "dsf")) != -1)
233 switch (c) {
234 case 'd':
235 devfs = 1;
236 break;
237 case 's':
238 requested_transition = single_user;
239 break;
240 case 'f':
241 runcom_mode = FASTBOOT;
242 break;
243 default:
244 warning("unrecognized flag '-%c'", c);
245 break;
246 }
247
248 if (optind != argc)
249 warning("ignoring excess arguments");
250
251 if (devfs) {
252 mount("devfs", "/dev", MNT_NOEXEC|MNT_RDONLY, 0);
253 }
254
255 /*
256 * We catch or block signals rather than ignore them,
257 * so that they get reset on exec.
258 */
259 handle(badsys, SIGSYS, 0);
260 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
261 SIGBUS, SIGXCPU, SIGXFSZ, 0);
262 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, 0);
263 handle(alrm_handler, SIGALRM, 0);
264 sigfillset(&mask);
265 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
266 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM, 0);
267 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
268 sigemptyset(&sa.sa_mask);
269 sa.sa_flags = 0;
270 sa.sa_handler = SIG_IGN;
271 (void) sigaction(SIGTTIN, &sa, (struct sigaction *)0);
272 (void) sigaction(SIGTTOU, &sa, (struct sigaction *)0);
273
274 /*
275 * Paranoia.
276 */
277 close(0);
278 close(1);
279 close(2);
280
281 /*
282 * Start the state machine.
283 */
284 transition(requested_transition);
285
286 /*
287 * Should never reach here.
288 */
289 return 1;
290}
291
292/*
293 * Associate a function with a signal handler.
294 */
295void
296#ifdef __STDC__
297handle(sig_t handler, ...)
298#else
299handle(va_alist)
300 va_dcl
301#endif
302{
303 int sig;
304 struct sigaction sa;
305 int mask_everything;
306 va_list ap;
307#ifndef __STDC__
308 sig_t handler;
309
310 va_start(ap);
311 handler = va_arg(ap, sig_t);
312#else
313 va_start(ap, handler);
314#endif
315
316 sa.sa_handler = handler;
317 sigfillset(&mask_everything);
318
319 while (sig = va_arg(ap, int)) {
320 sa.sa_mask = mask_everything;
321 /* XXX SA_RESTART? */
322 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
323 sigaction(sig, &sa, (struct sigaction *) 0);
324 }
325 va_end(ap);
326}
327
328/*
329 * Delete a set of signals from a mask.
330 */
331void
332#ifdef __STDC__
333delset(sigset_t *maskp, ...)
334#else
335delset(va_alist)
336 va_dcl
337#endif
338{
339 int sig;
340 va_list ap;
341#ifndef __STDC__
342 sigset_t *maskp;
343
344 va_start(ap);
345 maskp = va_arg(ap, sigset_t *);
346#else
347 va_start(ap, maskp);
348#endif
349
350 while (sig = va_arg(ap, int))
351 sigdelset(maskp, sig);
352 va_end(ap);
353}
354
355/*
356 * Log a message and sleep for a while (to give someone an opportunity
357 * to read it and to save log or hardcopy output if the problem is chronic).
358 * NB: should send a message to the session logger to avoid blocking.
359 */
360void
361#ifdef __STDC__
362stall(char *message, ...)
363#else
364stall(va_alist)
365 va_dcl
366#endif
367{
368 va_list ap;
369#ifndef __STDC__
370 char *message;
371
372 va_start(ap);
373 message = va_arg(ap, char *);
374#else
375 va_start(ap, message);
376#endif
377
378 vsyslog(LOG_ALERT, message, ap);
379 va_end(ap);
380 sleep(STALL_TIMEOUT);
381}
382
383/*
384 * Like stall(), but doesn't sleep.
385 * If cpp had variadic macros, the two functions could be #defines for another.
386 * NB: should send a message to the session logger to avoid blocking.
387 */
388void
389#ifdef __STDC__
390warning(char *message, ...)
391#else
392warning(va_alist)
393 va_dcl
394#endif
395{
396 va_list ap;
397#ifndef __STDC__
398 char *message;
399
400 va_start(ap);
401 message = va_arg(ap, char *);
402#else
403 va_start(ap, message);
404#endif
405
406 vsyslog(LOG_ALERT, message, ap);
407 va_end(ap);
408}
409
410/*
411 * Log an emergency message.
412 * NB: should send a message to the session logger to avoid blocking.
413 */
414void
415#ifdef __STDC__
416emergency(char *message, ...)
417#else
418emergency(va_alist)
419 va_dcl
420#endif
421{
422 va_list ap;
423#ifndef __STDC__
424 char *message;
425
426 va_start(ap);
427 message = va_arg(ap, char *);
428#else
429 va_start(ap, message);
430#endif
431
432 vsyslog(LOG_EMERG, message, ap);
433 va_end(ap);
434}
435
436/*
437 * Catch a SIGSYS signal.
438 *
439 * These may arise if a system does not support sysctl.
440 * We tolerate up to 25 of these, then throw in the towel.
441 */
442void
443badsys(sig)
444 int sig;
445{
446 static int badcount = 0;
447
448 if (badcount++ < 25)
449 return;
450 disaster(sig);
451}
452
453/*
454 * Catch an unexpected signal.
455 */
456void
457disaster(sig)
458 int sig;
459{
460 emergency("fatal signal: %s",
461 sig < (unsigned) NSIG ? sys_siglist[sig] : "unknown signal");
462
463 sleep(STALL_TIMEOUT);
464 _exit(sig); /* reboot */
465}
466
467/*
468 * Get the security level of the kernel.
469 */
470int
471getsecuritylevel()
472{
473#ifdef KERN_SECURELVL
474 int name[2], curlevel;
475 size_t len;
476 extern int errno;
477
478 name[0] = CTL_KERN;
479 name[1] = KERN_SECURELVL;
480 len = sizeof curlevel;
481 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
482 emergency("cannot get kernel security level: %s",
483 strerror(errno));
484 return (-1);
485 }
486 return (curlevel);
487#else
488 return (-1);
489#endif
490}
491
492/*
493 * Set the security level of the kernel.
494 */
495void
496setsecuritylevel(newlevel)
497 int newlevel;
498{
499#ifdef KERN_SECURELVL
500 int name[2], curlevel;
501 extern int errno;
502
503 curlevel = getsecuritylevel();
504 if (newlevel == curlevel)
505 return;
506 name[0] = CTL_KERN;
507 name[1] = KERN_SECURELVL;
508 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
509 emergency(
510 "cannot change kernel security level from %d to %d: %s",
511 curlevel, newlevel, strerror(errno));
512 return;
513 }
514#ifdef SECURE
515 warning("kernel security level changed from %d to %d",
516 curlevel, newlevel);
517#endif
518#endif
519}
520
521/*
522 * Change states in the finite state machine.
523 * The initial state is passed as an argument.
524 */
525void
526transition(s)
527 state_t s;
528{
529 for (;;)
530 s = (state_t) (*s)();
531}
532
533/*
534 * Close out the accounting files for a login session.
535 * NB: should send a message to the session logger to avoid blocking.
536 */
537void
538clear_session_logs(sp)
539 session_t *sp;
540{
541 char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
542
543 if (logout(line))
544 logwtmp(line, "", "");
545}
546
547/*
548 * Start a session and allocate a controlling terminal.
549 * Only called by children of init after forking.
550 */
551void
552setctty(name)
553 char *name;
554{
555 int fd;
556
557 (void) revoke(name);
558 if ((fd = open(name, O_RDWR)) == -1) {
559 stall("can't open %s: %m", name);
560 _exit(1);
561 }
562 if (login_tty(fd) == -1) {
563 stall("can't get %s for controlling terminal: %m", name);
564 _exit(1);
565 }
566}
567
568/*
569 * Bring the system up single user.
570 */
571state_func_t
572single_user()
573{
574 pid_t pid, wpid;
575 int status;
576 sigset_t mask;
577 char *shell = _PATH_BSHELL;
578 char *argv[2];
579#ifdef SECURE
580 struct ttyent *typ;
581 struct passwd *pp;
582 static const char banner[] =
583 "Enter root password, or ^D to go multi-user\n";
584 char *clear, *password;
585#endif
586
587 /*
588 * If the kernel is in secure mode, downgrade it to insecure mode.
589 */
590 if (getsecuritylevel() > 0)
591 setsecuritylevel(0);
592
593 if (Reboot) {
594 /* Instead of going single user, let's halt the machine */
595 sync();
596 alarm(2);
597 pause();
598 reboot(RB_AUTOBOOT);
599 _exit(0);
600 }
601
602 if ((pid = fork()) == 0) {
603 /*
604 * Start the single user session.
605 */
606 setctty(_PATH_CONSOLE);
607
608#ifdef SECURE
609 /*
610 * Check the root password.
611 * We don't care if the console is 'on' by default;
612 * it's the only tty that can be 'off' and 'secure'.
613 */
614 typ = getttynam("console");
615 pp = getpwnam("root");
616 if (typ && (typ->ty_status & TTY_SECURE) == 0 && pp && *pp->pw_passwd) {
617 write(2, banner, sizeof banner - 1);
618 for (;;) {
619 clear = getpass("Password:");
620 if (clear == 0 || *clear == '\0')
621 _exit(0);
622 password = crypt(clear, pp->pw_passwd);
623 bzero(clear, _PASSWORD_LEN);
624 if (strcmp(password, pp->pw_passwd) == 0)
625 break;
626 warning("single-user login failed\n");
627 }
628 }
629 endttyent();
630 endpwent();
631#endif /* SECURE */
632
633#ifdef DEBUGSHELL
634 {
635 char altshell[128], *cp = altshell;
636 int num;
637
638#define SHREQUEST \
639 "Enter pathname of shell or RETURN for sh: "
640 (void)write(STDERR_FILENO,
641 SHREQUEST, sizeof(SHREQUEST) - 1);
642 while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
643 num != 0 && *cp != '\n' && cp < &altshell[127])
644 cp++;
645 *cp = '\0';
646 if (altshell[0] != '\0')
647 shell = altshell;
648 }
649#endif /* DEBUGSHELL */
650
651 /*
652 * Unblock signals.
653 * We catch all the interesting ones,
654 * and those are reset to SIG_DFL on exec.
655 */
656 sigemptyset(&mask);
657 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
658
659 /*
660 * Fire off a shell.
661 * If the default one doesn't work, try the Bourne shell.
662 */
663 argv[0] = "-sh";
664 argv[1] = 0;
665 execv(shell, argv);
666 emergency("can't exec %s for single user: %m", shell);
667 execv(_PATH_BSHELL, argv);
668 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
669 sleep(STALL_TIMEOUT);
670 _exit(1);
671 }
672
673 if (pid == -1) {
674 /*
675 * We are seriously hosed. Do our best.
676 */
677 emergency("can't fork single-user shell, trying again");
678 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
679 continue;
680 return (state_func_t) single_user;
681 }
682
683 requested_transition = 0;
684 do {
685 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
686 collect_child(wpid);
687 if (wpid == -1) {
688 if (errno == EINTR)
689 continue;
690 warning("wait for single-user shell failed: %m; restarting");
691 return (state_func_t) single_user;
692 }
693 if (wpid == pid && WIFSTOPPED(status)) {
694 warning("init: shell stopped, restarting\n");
695 kill(pid, SIGCONT);
696 wpid = -1;
697 }
698 } while (wpid != pid && !requested_transition);
699
700 if (requested_transition)
701 return (state_func_t) requested_transition;
702
703 if (!WIFEXITED(status)) {
704 if (WTERMSIG(status) == SIGKILL) {
705 /*
706 * reboot(8) killed shell?
707 */
708 warning("single user shell terminated.");
709 sleep(STALL_TIMEOUT);
710 _exit(0);
711 } else {
712 warning("single user shell terminated, restarting");
713 return (state_func_t) single_user;
714 }
715 }
716
717 runcom_mode = FASTBOOT;
718 return (state_func_t) runcom;
719}
720
721/*
722 * Run the system startup script.
723 */
724state_func_t
725runcom()
726{
727 pid_t pid, wpid;
728 int status;
729 char *argv[4];
730 struct sigaction sa;
731
732 if ((pid = fork()) == 0) {
733 sigemptyset(&sa.sa_mask);
734 sa.sa_flags = 0;
735 sa.sa_handler = SIG_IGN;
736 (void) sigaction(SIGTSTP, &sa, (struct sigaction *)0);
737 (void) sigaction(SIGHUP, &sa, (struct sigaction *)0);
738
739 setctty(_PATH_CONSOLE);
740
741 argv[0] = "sh";
742 argv[1] = _PATH_RUNCOM;
743 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
744 argv[3] = 0;
745
746 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0);
747
748#ifdef LOGIN_CAP
749 setprocresources(RESOURCE_RC);
750#endif
751 execv(_PATH_BSHELL, argv);
752 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
753 _exit(1); /* force single user mode */
754 }
755
756 if (pid == -1) {
757 emergency("can't fork for %s on %s: %m",
758 _PATH_BSHELL, _PATH_RUNCOM);
759 while (waitpid(-1, (int *) 0, WNOHANG) > 0)
760 continue;
761 sleep(STALL_TIMEOUT);
762 return (state_func_t) single_user;
763 }
764
765 /*
766 * Copied from single_user(). This is a bit paranoid.
767 */
768 do {
769 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
770 collect_child(wpid);
771 if (wpid == -1) {
772 if (errno == EINTR)
773 continue;
774 warning("wait for %s on %s failed: %m; going to single user mode",
775 _PATH_BSHELL, _PATH_RUNCOM);
776 return (state_func_t) single_user;
777 }
778 if (wpid == pid && WIFSTOPPED(status)) {
779 warning("init: %s on %s stopped, restarting\n",
780 _PATH_BSHELL, _PATH_RUNCOM);
781 kill(pid, SIGCONT);
782 wpid = -1;
783 }
784 } while (wpid != pid);
785
786 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
787 requested_transition == catatonia) {
788 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
789 sigset_t s;
790
791 sigfillset(&s);
792 for (;;)
793 sigsuspend(&s);
794 }
795
796 if (!WIFEXITED(status)) {
797 warning("%s on %s terminated abnormally, going to single user mode",
798 _PATH_BSHELL, _PATH_RUNCOM);
799 return (state_func_t) single_user;
800 }
801
802 if (WEXITSTATUS(status))
803 return (state_func_t) single_user;
804
805 runcom_mode = AUTOBOOT; /* the default */
806 /* NB: should send a message to the session logger to avoid blocking. */
807 logwtmp("~", "reboot", "");
808 return (state_func_t) read_ttys;
809}
810
811/*
812 * Open the session database.
813 *
814 * NB: We could pass in the size here; is it necessary?
815 */
816int
817start_session_db()
818{
819 if (session_db && (*session_db->close)(session_db))
820 emergency("session database close: %s", strerror(errno));
821 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) {
822 emergency("session database open: %s", strerror(errno));
823 return (1);
824 }
825 return (0);
826
827}
828
829/*
830 * Add a new login session.
831 */
832void
833add_session(sp)
834 session_t *sp;
835{
836 DBT key;
837 DBT data;
838
839 key.data = &sp->se_process;
840 key.size = sizeof sp->se_process;
841 data.data = &sp;
842 data.size = sizeof sp;
843
844 if ((*session_db->put)(session_db, &key, &data, 0))
845 emergency("insert %d: %s", sp->se_process, strerror(errno));
846}
847
848/*
849 * Delete an old login session.
850 */
851void
852del_session(sp)
853 session_t *sp;
854{
855 DBT key;
856
857 key.data = &sp->se_process;
858 key.size = sizeof sp->se_process;
859
860 if ((*session_db->del)(session_db, &key, 0))
861 emergency("delete %d: %s", sp->se_process, strerror(errno));
862}
863
864/*
865 * Look up a login session by pid.
866 */
867session_t *
868#ifdef __STDC__
869find_session(pid_t pid)
870#else
871find_session(pid)
872 pid_t pid;
873#endif
874{
875 DBT key;
876 DBT data;
877 session_t *ret;
878
879 key.data = &pid;
880 key.size = sizeof pid;
881 if ((*session_db->get)(session_db, &key, &data, 0) != 0)
882 return 0;
883 bcopy(data.data, (char *)&ret, sizeof(ret));
884 return ret;
885}
886
887/*
888 * Construct an argument vector from a command line.
889 */
890char **
891construct_argv(command)
892 char *command;
893{
894 char *strk (char *);
895 register int argc = 0;
896 register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)
897 * sizeof (char *));
898
899 if ((argv[argc++] = strk(command)) == 0)
900 return 0;
901 while (argv[argc++] = strk((char *) 0))
902 continue;
903 return argv;
904}
905
906/*
907 * Deallocate a session descriptor.
908 */
909void
910free_session(sp)
911 register session_t *sp;
912{
913 free(sp->se_device);
914 if (sp->se_getty) {
915 free(sp->se_getty);
916 free(sp->se_getty_argv_space);
917 free(sp->se_getty_argv);
918 }
919 if (sp->se_window) {
920 free(sp->se_window);
921 free(sp->se_window_argv_space);
922 free(sp->se_window_argv);
923 }
924 if (sp->se_type)
925 free(sp->se_type);
926 free(sp);
927}
928
929/*
930 * Allocate a new session descriptor.
931 */
932session_t *
933new_session(sprev, session_index, typ)
934 session_t *sprev;
935 int session_index;
936 register struct ttyent *typ;
937{
938 register session_t *sp;
939
940 if ((typ->ty_status & TTY_ON) == 0 ||
941 typ->ty_name == 0 ||
942 typ->ty_getty == 0)
943 return 0;
944
945 sp = (session_t *) malloc(sizeof (session_t));
946 bzero(sp, sizeof *sp);
947
948 sp->se_index = session_index;
949
950 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
951 (void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
952
953 if (setupargv(sp, typ) == 0) {
954 free_session(sp);
955 return (0);
956 }
957
958 sp->se_next = 0;
959 if (sprev == 0) {
960 sessions = sp;
961 sp->se_prev = 0;
962 } else {
963 sprev->se_next = sp;
964 sp->se_prev = sprev;
965 }
966
967 return sp;
968}
969
970/*
971 * Calculate getty and if useful window argv vectors.
972 */
973int
974setupargv(sp, typ)
975 session_t *sp;
976 struct ttyent *typ;
977{
978
979 if (sp->se_getty) {
980 free(sp->se_getty);
981 free(sp->se_getty_argv_space);
982 free(sp->se_getty_argv);
983 }
984 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
985 (void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
986 sp->se_getty_argv_space = strdup(sp->se_getty);
987 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
988 if (sp->se_getty_argv == 0) {
989 warning("can't parse getty for port %s", sp->se_device);
990 free(sp->se_getty);
991 free(sp->se_getty_argv_space);
992 sp->se_getty = sp->se_getty_argv_space = 0;
993 return (0);
994 }
995 if (sp->se_window) {
996 free(sp->se_window);
997 free(sp->se_window_argv_space);
998 free(sp->se_window_argv);
999 }
1000 sp->se_window = sp->se_window_argv_space = 0;
1001 sp->se_window_argv = 0;
1002 if (typ->ty_window) {
1003 sp->se_window = strdup(typ->ty_window);
1004 sp->se_window_argv_space = strdup(sp->se_window);
1005 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1006 if (sp->se_window_argv == 0) {
1007 warning("can't parse window for port %s",
1008 sp->se_device);
1009 free(sp->se_window_argv_space);
1010 free(sp->se_window);
1011 sp->se_window = sp->se_window_argv_space = 0;
1012 return (0);
1013 }
1014 }
1015 if (sp->se_type)
1016 free(sp->se_type);
1017 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1018 return (1);
1019}
1020
1021/*
1022 * Walk the list of ttys and create sessions for each active line.
1023 */
1024state_func_t
1025read_ttys()
1026{
1027 int session_index = 0;
1028 register session_t *sp, *snext;
1029 register struct ttyent *typ;
1030
1031 /*
1032 * Destroy any previous session state.
1033 * There shouldn't be any, but just in case...
1034 */
1035 for (sp = sessions; sp; sp = snext) {
1036 if (sp->se_process)
1037 clear_session_logs(sp);
1038 snext = sp->se_next;
1039 free_session(sp);
1040 }
1041 sessions = 0;
1042 if (start_session_db())
1043 return (state_func_t) single_user;
1044
1045 /*
1046 * Allocate a session entry for each active port.
1047 * Note that sp starts at 0.
1048 */
1049 while (typ = getttyent())
1050 if (snext = new_session(sp, ++session_index, typ))
1051 sp = snext;
1052
1053 endttyent();
1054
1055 return (state_func_t) multi_user;
1056}
1057
1058/*
1059 * Start a window system running.
1060 */
1061void
1062start_window_system(sp)
1063 session_t *sp;
1064{
1065 pid_t pid;
1066 sigset_t mask;
1067 char term[64], *env[2];
1068
1069 if ((pid = fork()) == -1) {
1070 emergency("can't fork for window system on port %s: %m",
1071 sp->se_device);
1072 /* hope that getty fails and we can try again */
1073 return;
1074 }
1075
1076 if (pid)
1077 return;
1078
1079 sigemptyset(&mask);
1080 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1081
1082 if (setsid() < 0)
1083 emergency("setsid failed (window) %m");
1084
1085#ifdef LOGIN_CAP
1086 setprocresources(RESOURCE_WINDOW);
1087#endif
1088 if (sp->se_type) {
1089 /* Don't use malloc after fork */
1090 strcpy(term, "TERM=");
1091 strncat(term, sp->se_type, sizeof(term) - 6);
1092 env[0] = term;
1093 env[1] = 0;
1094 }
1095 else
1096 env[0] = 0;
1097 execve(sp->se_window_argv[0], sp->se_window_argv, env);
1098 stall("can't exec window system '%s' for port %s: %m",
1099 sp->se_window_argv[0], sp->se_device);
1100 _exit(1);
1101}
1102
1103/*
1104 * Start a login session running.
1105 */
1106pid_t
1107start_getty(sp)
1108 session_t *sp;
1109{
1110 pid_t pid;
1111 sigset_t mask;
1112 time_t current_time = time((time_t *) 0);
1113 int too_quick = 0;
1114 char term[64], *env[2];
1115
1116 if (current_time >= sp->se_started &&
1117 current_time - sp->se_started < GETTY_SPACING) {
1118 if (++sp->se_nspace > GETTY_NSPACE) {
1119 sp->se_nspace = 0;
1120 too_quick = 1;
1121 }
1122 } else
1123 sp->se_nspace = 0;
1124
1125 /*
1126 * fork(), not vfork() -- we can't afford to block.
1127 */
1128 if ((pid = fork()) == -1) {
1129 emergency("can't fork for getty on port %s: %m", sp->se_device);
1130 return -1;
1131 }
1132
1133 if (pid)
1134 return pid;
1135
1136 if (too_quick) {
1137 warning("getty repeating too quickly on port %s, sleeping %d secs",
1138 sp->se_device, GETTY_SLEEP);
1139 sleep((unsigned) GETTY_SLEEP);
1140 }
1141
1142 if (sp->se_window) {
1143 start_window_system(sp);
1144 sleep(WINDOW_WAIT);
1145 }
1146
1147 sigemptyset(&mask);
1148 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0);
1149
1150#ifdef LOGIN_CAP
1151 setprocresources(RESOURCE_GETTY);
1152#endif
1153 if (sp->se_type) {
1154 /* Don't use malloc after fork */
1155 strcpy(term, "TERM=");
1156 strncat(term, sp->se_type, sizeof(term) - 6);
1157 env[0] = term;
1158 env[1] = 0;
1159 }
1160 else
1161 env[0] = 0;
1162 execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1163 stall("can't exec getty '%s' for port %s: %m",
1164 sp->se_getty_argv[0], sp->se_device);
1165 _exit(1);
1166}
1167
1168/*
1169 * Collect exit status for a child.
1170 * If an exiting login, start a new login running.
1171 */
1172void
1173#ifdef __STDC__
1174collect_child(pid_t pid)
1175#else
1176collect_child(pid)
1177 pid_t pid;
1178#endif
1179{
1180 register session_t *sp, *sprev, *snext;
1181
1182 if (! sessions)
1183 return;
1184
1185 if (! (sp = find_session(pid)))
1186 return;
1187
1188 clear_session_logs(sp);
1189 del_session(sp);
1190 sp->se_process = 0;
1191
1192 if (sp->se_flags & SE_SHUTDOWN) {
1193 if (sprev = sp->se_prev)
1194 sprev->se_next = sp->se_next;
1195 else
1196 sessions = sp->se_next;
1197 if (snext = sp->se_next)
1198 snext->se_prev = sp->se_prev;
1199 free_session(sp);
1200 return;
1201 }
1202
1203 if ((pid = start_getty(sp)) == -1) {
1204 /* serious trouble */
1205 requested_transition = clean_ttys;
1206 return;
1207 }
1208
1209 sp->se_process = pid;
1210 sp->se_started = time((time_t *) 0);
1211 add_session(sp);
1212}
1213
1214/*
1215 * Catch a signal and request a state transition.
1216 */
1217void
1218transition_handler(sig)
1219 int sig;
1220{
1221
1222 switch (sig) {
1223 case SIGHUP:
1224 requested_transition = clean_ttys;
1225 break;
1226 case SIGINT:
1227 Reboot = TRUE;
1228 case SIGTERM:
1229 requested_transition = death;
1230 break;
1231 case SIGTSTP:
1232 requested_transition = catatonia;
1233 break;
1234 default:
1235 requested_transition = 0;
1236 break;
1237 }
1238}
1239
1240/*
1241 * Take the system multiuser.
1242 */
1243state_func_t
1244multi_user()
1245{
1246 pid_t pid;
1247 register session_t *sp;
1248
1249 requested_transition = 0;
1250
1251 /*
1252 * If the administrator has not set the security level to -1
1253 * to indicate that the kernel should not run multiuser in secure
1254 * mode, and the run script has not set a higher level of security
1255 * than level 1, then put the kernel into secure mode.
1256 */
1257 if (getsecuritylevel() == 0)
1258 setsecuritylevel(1);
1259
1260 for (sp = sessions; sp; sp = sp->se_next) {
1261 if (sp->se_process)
1262 continue;
1263 if ((pid = start_getty(sp)) == -1) {
1264 /* serious trouble */
1265 requested_transition = clean_ttys;
1266 break;
1267 }
1268 sp->se_process = pid;
1269 sp->se_started = time((time_t *) 0);
1270 add_session(sp);
1271 }
1272
1273 while (!requested_transition)
1274 if ((pid = waitpid(-1, (int *) 0, 0)) != -1)
1275 collect_child(pid);
1276
1277 return (state_func_t) requested_transition;
1278}
1279
1280/*
1281 * This is an n-squared algorithm. We hope it isn't run often...
1282 */
1283state_func_t
1284clean_ttys()
1285{
1286 register session_t *sp, *sprev;
1287 register struct ttyent *typ;
1288 register int session_index = 0;
1289 register int devlen;
1290 char *old_getty, *old_window, *old_type;
1291
1292 if (! sessions)
1293 return (state_func_t) multi_user;
1294
1295 devlen = sizeof(_PATH_DEV) - 1;
1296 while (typ = getttyent()) {
1297 ++session_index;
1298
1299 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1300 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1301 break;
1302
1303 if (sp) {
1304 if (sp->se_index != session_index) {
1305 warning("port %s changed utmp index from %d to %d",
1306 sp->se_device, sp->se_index,
1307 session_index);
1308 sp->se_index = session_index;
1309 }
1310 if ((typ->ty_status & TTY_ON) == 0 ||
1311 typ->ty_getty == 0) {
1312 sp->se_flags |= SE_SHUTDOWN;
1313 kill(sp->se_process, SIGHUP);
1314 continue;
1315 }
1316 sp->se_flags &= ~SE_SHUTDOWN;
1317 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1318 old_window = sp->se_window ? strdup(sp->se_window) : 0;
1319 old_type = sp->se_type ? strdup(sp->se_type) : 0;
1320 if (setupargv(sp, typ) == 0) {
1321 warning("can't parse getty for port %s",
1322 sp->se_device);
1323 sp->se_flags |= SE_SHUTDOWN;
1324 kill(sp->se_process, SIGHUP);
1325 }
1326 else if ( !old_getty
1327 || !old_type && sp->se_type
1328 || old_type && !sp->se_type
1329 || !old_window && sp->se_window
1330 || old_window && !sp->se_window
1331 || strcmp(old_getty, sp->se_getty) != 0
1332 || old_window && strcmp(old_window, sp->se_window) != 0
1333 || old_type && strcmp(old_type, sp->se_type) != 0
1334 ) {
1335 /* Don't set SE_SHUTDOWN here */
1336 sp->se_nspace = 0;
1337 sp->se_started = 0;
1338 kill(sp->se_process, SIGHUP);
1339 }
1340 if (old_getty)
1341 free(old_getty);
1342 if (old_getty)
1343 free(old_window);
1344 if (old_type)
1345 free(old_type);
1346 continue;
1347 }
1348
1349 new_session(sprev, session_index, typ);
1350 }
1351
1352 endttyent();
1353
1354 return (state_func_t) multi_user;
1355}
1356
1357/*
1358 * Block further logins.
1359 */
1360state_func_t
1361catatonia()
1362{
1363 register session_t *sp;
1364
1365 for (sp = sessions; sp; sp = sp->se_next)
1366 sp->se_flags |= SE_SHUTDOWN;
1367
1368 return (state_func_t) multi_user;
1369}
1370
1371/*
1372 * Note SIGALRM.
1373 */
1374void
1375alrm_handler(sig)
1376 int sig;
1377{
1378 clang = 1;
1379}
1380
1381/*
1382 * Bring the system down to single user.
1383 */
1384state_func_t
1385death()
1386{
1387 register session_t *sp;
1388 register int i;
1389 pid_t pid;
1390 static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL };
1391
1392 for (sp = sessions; sp; sp = sp->se_next)
1393 sp->se_flags |= SE_SHUTDOWN;
1394
1395 /* NB: should send a message to the session logger to avoid blocking. */
1396 logwtmp("~", "shutdown", "");
1397
1398 for (i = 0; i < 3; ++i) {
1399 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1400 return (state_func_t) single_user;
1401
1402 clang = 0;
1403 alarm(DEATH_WATCH);
1404 do
1405 if ((pid = waitpid(-1, (int *)0, 0)) != -1)
1406 collect_child(pid);
1407 while (clang == 0 && errno != ECHILD);
1408
1409 if (errno == ECHILD)
1410 return (state_func_t) single_user;
1411 }
1412
1413 warning("some processes would not die; ps axl advised");
1414
1415 return (state_func_t) single_user;
1416}
1417char *
1418strk (char *p)
1419{
1420 static char *t;
1421 char *q;
1422 int c;
1423
1424 if (p)
1425 t = p;
1426 if (!t)
1427 return 0;
1428
1429 c = *t;
1430 while (c == ' ' || c == '\t' )
1431 c = *++t;
1432 if (!c) {
1433 t = 0;
1434 return 0;
1435 }
1436 q = t;
1437 if (c == '\'') {
1438 c = *++t;
1439 q = t;
1440 while (c && c != '\'')
1441 c = *++t;
1442 if (!c) /* unterminated string */
1443 q = t = 0;
1444 else
1445 *t++ = 0;
1446 } else {
1447 while (c && c != ' ' && c != '\t' )
1448 c = *++t;
1449 *t++ = 0;
1450 if (!c)
1451 t = 0;
1452 }
1453 return q;
1454}
1455
1456#ifdef LOGIN_CAP
1457void
1458setprocresources(cname)
1459 const char *cname;
1460{
1461 login_cap_t *lc;
1462 if ((lc = login_getclassbyname(cname, (char*)NULL)) != NULL) {
1463 setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1464 login_close(lc);
1465 }
1466}
1467#endif