init.c revision 1.35
1 /* $NetBSD: init.c,v 1.35 1999/11/09 15:06:33 drochner Exp $ */ 2 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\n" 42 " The Regents of the University of California. All rights reserved.\n"); 43 #endif /* not lint */ 44 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)init.c 8.2 (Berkeley) 4/28/95"; 48 #else 49 __RCSID("$NetBSD: init.c,v 1.35 1999/11/09 15:06:33 drochner Exp $"); 50 #endif 51 #endif /* not lint */ 52 53 #include <sys/param.h> 54 #include <sys/sysctl.h> 55 #include <sys/wait.h> 56 #include <sys/mman.h> 57 #include <sys/stat.h> 58 #include <sys/mount.h> 59 #ifdef DEBUG 60 #include <sys/sysctl.h> 61 #include <machine/cpu.h> 62 #endif 63 64 #include <db.h> 65 #include <errno.h> 66 #include <fcntl.h> 67 #include <signal.h> 68 #include <stdio.h> 69 #include <stdlib.h> 70 #include <string.h> 71 #include <syslog.h> 72 #include <time.h> 73 #include <ttyent.h> 74 #include <unistd.h> 75 #include <util.h> 76 #include <paths.h> 77 #include <err.h> 78 79 #ifdef __STDC__ 80 #include <stdarg.h> 81 #else 82 #include <varargs.h> 83 #endif 84 85 #ifdef SECURE 86 #include <pwd.h> 87 #endif 88 89 #include "pathnames.h" 90 91 /* 92 * Sleep times; used to prevent thrashing. 93 */ 94 #define GETTY_SPACING 5 /* N secs minimum getty spacing */ 95 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 96 #define WINDOW_WAIT 3 /* wait N secs after starting window */ 97 #define STALL_TIMEOUT 30 /* wait N secs after warning */ 98 #define DEATH_WATCH 10 /* wait N secs for procs to die */ 99 100 int main __P((int, char *[])); 101 102 void handle __P((sig_t, ...)); 103 void delset __P((sigset_t *, ...)); 104 105 void stall __P((const char *, ...)) 106 __attribute__((__format__(__printf__,1,2))); 107 void warning __P((const char *, ...)) 108 __attribute__((__format__(__printf__,1,2))); 109 void emergency __P((const char *, ...)) 110 __attribute__((__format__(__printf__,1,2))); 111 void disaster __P((int)); 112 void badsys __P((int)); 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) __P((void)); 120 typedef state_func_t (*state_t) __P((void)); 121 122 state_func_t single_user __P((void)); 123 state_func_t runcom __P((void)); 124 state_func_t read_ttys __P((void)); 125 state_func_t multi_user __P((void)); 126 state_func_t clean_ttys __P((void)); 127 state_func_t catatonia __P((void)); 128 state_func_t death __P((void)); 129 130 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 131 132 void transition __P((state_t)); 133 #ifndef LETS_GET_SMALL 134 state_t requested_transition = runcom; 135 #else /* LETS_GET_SMALL */ 136 state_t requested_transition = single_user; 137 #endif /* LETS_GET_SMALL */ 138 139 void setctty __P((char *)); 140 141 typedef struct init_session { 142 int se_index; /* index of entry in ttys file */ 143 pid_t se_process; /* controlling process */ 144 time_t se_started; /* used to avoid thrashing */ 145 int se_flags; /* status of session */ 146 #define SE_SHUTDOWN 0x1 /* session won't be restarted */ 147 #define SE_PRESENT 0x2 /* session is in /etc/ttys */ 148 char *se_device; /* filename of port */ 149 char *se_getty; /* what to run on that port */ 150 char **se_getty_argv; /* pre-parsed argument array */ 151 char *se_window; /* window system (started only once) */ 152 char **se_window_argv; /* pre-parsed argument array */ 153 struct init_session *se_prev; 154 struct init_session *se_next; 155 } session_t; 156 157 void free_session __P((session_t *)); 158 session_t *new_session __P((session_t *, int, struct ttyent *)); 159 session_t *sessions; 160 161 char **construct_argv __P((char *)); 162 void start_window_system __P((session_t *)); 163 void collect_child __P((pid_t)); 164 pid_t start_getty __P((session_t *)); 165 void transition_handler __P((int)); 166 void alrm_handler __P((int)); 167 void setsecuritylevel __P((int)); 168 int getsecuritylevel __P((void)); 169 int setupargv __P((session_t *, struct ttyent *)); 170 int clang; 171 172 void clear_session_logs __P((session_t *)); 173 174 int start_session_db __P((void)); 175 void add_session __P((session_t *)); 176 void del_session __P((session_t *)); 177 session_t *find_session __P((pid_t)); 178 DB *session_db; 179 180 #ifdef MSDOSFS_ROOT 181 static void msdosfs_root __P((void)); 182 #endif 183 184 /* 185 * The mother of all processes. 186 */ 187 int 188 main(argc, argv) 189 int argc; 190 char **argv; 191 { 192 int c; 193 struct sigaction sa; 194 sigset_t mask; 195 196 #ifndef LETS_GET_SMALL 197 /* Dispose of random users. */ 198 if (getuid() != 0) { 199 errno = EPERM; 200 err(1, NULL); 201 } 202 203 /* System V users like to reexec init. */ 204 if (getpid() != 1) 205 errx(1, "already running"); 206 #endif 207 208 /* 209 * Create an initial session. 210 */ 211 if (setsid() < 0) 212 warn("initial setsid() failed"); 213 214 /* 215 * Establish an initial user so that programs running 216 * single user do not freak out and die (like passwd). 217 */ 218 if (setlogin("root") < 0) 219 warn("setlogin() failed"); 220 221 222 #ifdef MSDOSFS_ROOT 223 msdosfs_root(); 224 #endif 225 226 #ifndef LETS_GET_SMALL 227 /* 228 * Note that this does NOT open a file... 229 * Does 'init' deserve its own facility number? 230 */ 231 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH); 232 #endif /* LETS_GET_SMALL */ 233 234 235 #ifndef LETS_GET_SMALL 236 /* 237 * This code assumes that we always get arguments through flags, 238 * never through bits set in some random machine register. 239 */ 240 while ((c = getopt(argc, argv, "sf")) != -1) 241 switch (c) { 242 case 's': 243 requested_transition = single_user; 244 break; 245 case 'f': 246 runcom_mode = FASTBOOT; 247 break; 248 default: 249 warning("unrecognized flag '-%c'", c); 250 break; 251 } 252 253 if (optind != argc) 254 warning("ignoring excess arguments"); 255 #else /* LETS_GET_SMALL */ 256 requested_transition = single_user; 257 #endif /* LETS_GET_SMALL */ 258 259 /* 260 * We catch or block signals rather than ignore them, 261 * so that they get reset on exec. 262 */ 263 handle(badsys, SIGSYS, 0); 264 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, 265 SIGBUS, SIGXCPU, SIGXFSZ, 0); 266 handle(transition_handler, SIGHUP, SIGTERM, SIGTSTP, 0); 267 handle(alrm_handler, SIGALRM, 0); 268 sigfillset(&mask); 269 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 270 SIGXCPU, SIGXFSZ, SIGHUP, SIGTERM, SIGTSTP, SIGALRM, 0); 271 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 272 sigemptyset(&sa.sa_mask); 273 sa.sa_flags = 0; 274 sa.sa_handler = SIG_IGN; 275 (void) sigaction(SIGTTIN, &sa, (struct sigaction *)0); 276 (void) sigaction(SIGTTOU, &sa, (struct sigaction *)0); 277 278 /* 279 * Paranoia. 280 */ 281 close(0); 282 close(1); 283 close(2); 284 285 /* 286 * Start the state machine. 287 */ 288 transition(requested_transition); 289 290 /* 291 * Should never reach here. 292 */ 293 return 1; 294 } 295 296 /* 297 * Associate a function with a signal handler. 298 */ 299 void 300 #ifdef __STDC__ 301 handle(sig_t handler, ...) 302 #else 303 handle(va_alist) 304 va_dcl 305 #endif 306 { 307 int sig; 308 struct sigaction sa; 309 sigset_t mask_everything; 310 va_list ap; 311 #ifndef __STDC__ 312 sig_t handler; 313 314 va_start(ap); 315 handler = va_arg(ap, sig_t); 316 #else 317 va_start(ap, handler); 318 #endif 319 320 sa.sa_handler = handler; 321 sigfillset(&mask_everything); 322 323 while ((sig = va_arg(ap, int)) != 0) { 324 sa.sa_mask = mask_everything; 325 /* XXX SA_RESTART? */ 326 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 327 sigaction(sig, &sa, (struct sigaction *) 0); 328 } 329 va_end(ap); 330 } 331 332 /* 333 * Delete a set of signals from a mask. 334 */ 335 void 336 #ifdef __STDC__ 337 delset(sigset_t *maskp, ...) 338 #else 339 delset(va_alist) 340 va_dcl 341 #endif 342 { 343 int sig; 344 va_list ap; 345 #ifndef __STDC__ 346 sigset_t *maskp; 347 348 va_start(ap); 349 maskp = va_arg(ap, sigset_t *); 350 #else 351 va_start(ap, maskp); 352 #endif 353 354 while ((sig = va_arg(ap, int)) != 0) 355 sigdelset(maskp, sig); 356 va_end(ap); 357 } 358 359 /* 360 * Log a message and sleep for a while (to give someone an opportunity 361 * to read it and to save log or hardcopy output if the problem is chronic). 362 * NB: should send a message to the session logger to avoid blocking. 363 */ 364 void 365 #ifdef __STDC__ 366 stall(const char *message, ...) 367 #else 368 stall(va_alist) 369 va_dcl 370 #endif 371 { 372 va_list ap; 373 #ifndef __STDC__ 374 char *message; 375 376 va_start(ap); 377 message = va_arg(ap, char *); 378 #else 379 va_start(ap, message); 380 #endif 381 vsyslog(LOG_ALERT, message, ap); 382 va_end(ap); 383 closelog(); 384 sleep(STALL_TIMEOUT); 385 } 386 387 /* 388 * Like stall(), but doesn't sleep. 389 * If cpp had variadic macros, the two functions could be #defines for another. 390 * NB: should send a message to the session logger to avoid blocking. 391 */ 392 void 393 #ifdef __STDC__ 394 warning(const char *message, ...) 395 #else 396 warning(va_alist) 397 va_dcl 398 #endif 399 { 400 va_list ap; 401 #ifndef __STDC__ 402 char *message; 403 404 va_start(ap); 405 message = va_arg(ap, char *); 406 #else 407 va_start(ap, message); 408 #endif 409 410 vsyslog(LOG_ALERT, message, ap); 411 va_end(ap); 412 closelog(); 413 } 414 415 /* 416 * Log an emergency message. 417 * NB: should send a message to the session logger to avoid blocking. 418 */ 419 void 420 #ifdef __STDC__ 421 emergency(const char *message, ...) 422 #else 423 emergency(va_alist) 424 va_dcl 425 #endif 426 { 427 va_list ap; 428 #ifndef __STDC__ 429 char *message; 430 431 va_start(ap); 432 message = va_arg(ap, char *); 433 #else 434 va_start(ap, message); 435 #endif 436 437 vsyslog(LOG_EMERG, message, ap); 438 va_end(ap); 439 closelog(); 440 } 441 442 /* 443 * Catch a SIGSYS signal. 444 * 445 * These may arise if a system does not support sysctl. 446 * We tolerate up to 25 of these, then throw in the towel. 447 */ 448 void 449 badsys(sig) 450 int sig; 451 { 452 static int badcount = 0; 453 454 if (badcount++ < 25) 455 return; 456 disaster(sig); 457 } 458 459 /* 460 * Catch an unexpected signal. 461 */ 462 void 463 disaster(sig) 464 int sig; 465 { 466 emergency("fatal signal: %s", strsignal(sig)); 467 468 sleep(STALL_TIMEOUT); 469 _exit(sig); /* reboot */ 470 } 471 472 /* 473 * Get the security level of the kernel. 474 */ 475 int 476 getsecuritylevel() 477 { 478 #ifdef KERN_SECURELVL 479 int name[2], curlevel; 480 size_t len; 481 extern int errno; 482 483 name[0] = CTL_KERN; 484 name[1] = KERN_SECURELVL; 485 len = sizeof curlevel; 486 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 487 emergency("cannot get kernel security level: %s", 488 strerror(errno)); 489 return (-1); 490 } 491 return (curlevel); 492 #else 493 return (-1); 494 #endif 495 } 496 497 /* 498 * Set the security level of the kernel. 499 */ 500 void 501 setsecuritylevel(newlevel) 502 int newlevel; 503 { 504 #ifdef KERN_SECURELVL 505 int name[2], curlevel; 506 extern int errno; 507 508 curlevel = getsecuritylevel(); 509 if (newlevel == curlevel) 510 return; 511 name[0] = CTL_KERN; 512 name[1] = KERN_SECURELVL; 513 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 514 emergency( 515 "cannot change kernel security level from %d to %d: %s", 516 curlevel, newlevel, strerror(errno)); 517 return; 518 } 519 #ifdef SECURE 520 warning("kernel security level changed from %d to %d", 521 curlevel, newlevel); 522 #endif 523 #endif 524 } 525 526 /* 527 * Change states in the finite state machine. 528 * The initial state is passed as an argument. 529 */ 530 void 531 transition(s) 532 state_t s; 533 { 534 for (;;) 535 s = (state_t) (*s)(); 536 } 537 538 /* 539 * Close out the accounting files for a login session. 540 * NB: should send a message to the session logger to avoid blocking. 541 */ 542 void 543 clear_session_logs(sp) 544 session_t *sp; 545 { 546 char *line = sp->se_device + sizeof(_PATH_DEV) - 1; 547 548 if (logout(line)) 549 logwtmp(line, "", ""); 550 } 551 552 /* 553 * Start a session and allocate a controlling terminal. 554 * Only called by children of init after forking. 555 */ 556 void 557 setctty(name) 558 char *name; 559 { 560 int fd; 561 562 (void) revoke(name); 563 sleep (2); /* leave DTR low */ 564 if ((fd = open(name, O_RDWR)) == -1) { 565 stall("can't open %s: %m", name); 566 _exit(1); 567 } 568 if (login_tty(fd) == -1) { 569 stall("can't get %s for controlling terminal: %m", name); 570 _exit(1); 571 } 572 } 573 574 /* 575 * Bring the system up single user. 576 */ 577 state_func_t 578 single_user() 579 { 580 pid_t pid, wpid; 581 int status; 582 int from_securitylevel; 583 sigset_t mask; 584 #ifdef ALTSHELL 585 char *shell = _PATH_BSHELL; 586 #endif 587 char *argv[2]; 588 #ifdef SECURE 589 struct ttyent *typ; 590 struct passwd *pp; 591 char *clear, *password; 592 #endif 593 #ifdef ALTSHELL 594 char altshell[128]; 595 #endif /* ALTSHELL */ 596 597 /* 598 * If the kernel is in secure mode, downgrade it to insecure mode. 599 */ 600 from_securitylevel = getsecuritylevel(); 601 if (from_securitylevel > 0) 602 setsecuritylevel(0); 603 604 if ((pid = fork()) == 0) { 605 /* 606 * Start the single user session. 607 */ 608 setctty(_PATH_CONSOLE); 609 610 #ifdef SECURE 611 /* 612 * Check the root password. 613 * We don't care if the console is 'on' by default; 614 * it's the only tty that can be 'off' and 'secure'. 615 */ 616 typ = getttynam("console"); 617 pp = getpwnam("root"); 618 if (typ && (from_securitylevel >=2 || (typ->ty_status 619 & TTY_SECURE) == 0) && pp && *pp->pw_passwd != '\0') { 620 fprintf(stderr, 621 "Enter root password, or ^D to go multi-user\n"); 622 for (;;) { 623 clear = getpass("Password:"); 624 if (clear == 0 || *clear == '\0') 625 _exit(0); 626 password = crypt(clear, pp->pw_passwd); 627 memset(clear, 0, _PASSWORD_LEN); 628 if (strcmp(password, pp->pw_passwd) == 0) 629 break; 630 warning("single-user login failed\n"); 631 } 632 } 633 endttyent(); 634 endpwent(); 635 #endif /* SECURE */ 636 637 #ifdef ALTSHELL 638 fprintf(stderr, "Enter pathname of shell or RETURN for sh: "); 639 fgets(altshell, sizeof(altshell), stdin); 640 /* nuke \n */ 641 altshell[strlen(altshell) - 1] = '\0'; 642 643 if (altshell[0]) 644 shell = altshell; 645 #endif /* ALTSHELL */ 646 647 /* 648 * Unblock signals. 649 * We catch all the interesting ones, 650 * and those are reset to SIG_DFL on exec. 651 */ 652 sigemptyset(&mask); 653 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 654 655 /* 656 * Fire off a shell. 657 * If the default one doesn't work, try the Bourne shell. 658 */ 659 argv[0] = "-sh"; 660 argv[1] = 0; 661 setenv("PATH", _PATH_STDPATH, 1); 662 #ifdef ALTSHELL 663 if (altshell[0]) 664 argv[0] = altshell; 665 execv(shell, argv); 666 emergency("can't exec %s for single user: %m", shell); 667 argv[0] = "-sh"; 668 #endif /* ALTSHELL */ 669 execv(_PATH_BSHELL, argv); 670 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 671 sleep(STALL_TIMEOUT); 672 _exit(1); 673 } 674 675 if (pid == -1) { 676 /* 677 * We are seriously hosed. Do our best. 678 */ 679 emergency("can't fork single-user shell, trying again"); 680 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 681 continue; 682 return (state_func_t) single_user; 683 } 684 685 requested_transition = 0; 686 do { 687 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 688 collect_child(wpid); 689 if (wpid == -1) { 690 if (errno == EINTR) 691 continue; 692 warning("wait for single-user shell failed: %m; restarting"); 693 return (state_func_t) single_user; 694 } 695 if (wpid == pid && WIFSTOPPED(status)) { 696 warning("init: shell stopped, restarting\n"); 697 kill(pid, SIGCONT); 698 wpid = -1; 699 } 700 } while (wpid != pid && !requested_transition); 701 702 if (requested_transition) 703 return (state_func_t) requested_transition; 704 705 if (!WIFEXITED(status)) { 706 if (WTERMSIG(status) == SIGKILL) { 707 /* 708 * reboot(8) killed shell? 709 */ 710 warning("single user shell terminated."); 711 sleep(STALL_TIMEOUT); 712 _exit(0); 713 } else { 714 warning("single user shell terminated, restarting"); 715 return (state_func_t) single_user; 716 } 717 } 718 719 runcom_mode = FASTBOOT; 720 #ifndef LETS_GET_SMALL 721 return (state_func_t) runcom; 722 #else /* LETS_GET_SMALL */ 723 return (state_func_t) single_user; 724 #endif /* LETS_GET_SMALL */ 725 } 726 727 #ifndef LETS_GET_SMALL 728 /* 729 * Run the system startup script. 730 */ 731 state_func_t 732 runcom() 733 { 734 pid_t pid, wpid; 735 int status; 736 char *argv[4]; 737 struct sigaction sa; 738 739 if ((pid = fork()) == 0) { 740 sigemptyset(&sa.sa_mask); 741 sa.sa_flags = 0; 742 sa.sa_handler = SIG_IGN; 743 (void) sigaction(SIGTSTP, &sa, (struct sigaction *)0); 744 (void) sigaction(SIGHUP, &sa, (struct sigaction *)0); 745 746 setctty(_PATH_CONSOLE); 747 748 argv[0] = "sh"; 749 argv[1] = _PATH_RUNCOM; 750 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0; 751 argv[3] = 0; 752 753 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 754 755 execv(_PATH_BSHELL, argv); 756 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM); 757 _exit(1); /* force single user mode */ 758 } 759 760 if (pid == -1) { 761 emergency("can't fork for %s on %s: %m", 762 _PATH_BSHELL, _PATH_RUNCOM); 763 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 764 continue; 765 sleep(STALL_TIMEOUT); 766 return (state_func_t) single_user; 767 } 768 769 /* 770 * Copied from single_user(). This is a bit paranoid. 771 */ 772 do { 773 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 774 collect_child(wpid); 775 if (wpid == -1) { 776 if (errno == EINTR) 777 continue; 778 warning("wait for %s on %s failed: %m; going to single user mode", 779 _PATH_BSHELL, _PATH_RUNCOM); 780 return (state_func_t) single_user; 781 } 782 if (wpid == pid && WIFSTOPPED(status)) { 783 warning("init: %s on %s stopped, restarting\n", 784 _PATH_BSHELL, _PATH_RUNCOM); 785 kill(pid, SIGCONT); 786 wpid = -1; 787 } 788 } while (wpid != pid); 789 790 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 791 requested_transition == catatonia) { 792 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 793 sigset_t s; 794 795 sigfillset(&s); 796 for (;;) 797 sigsuspend(&s); 798 } 799 800 if (!WIFEXITED(status)) { 801 warning("%s on %s terminated abnormally, going to single user mode", 802 _PATH_BSHELL, _PATH_RUNCOM); 803 return (state_func_t) single_user; 804 } 805 806 if (WEXITSTATUS(status)) 807 return (state_func_t) single_user; 808 809 runcom_mode = AUTOBOOT; /* the default */ 810 /* NB: should send a message to the session logger to avoid blocking. */ 811 logwtmp("~", "reboot", ""); 812 return (state_func_t) read_ttys; 813 } 814 815 /* 816 * Open the session database. 817 * 818 * NB: We could pass in the size here; is it necessary? 819 */ 820 int 821 start_session_db() 822 { 823 if (session_db && (*session_db->close)(session_db)) 824 emergency("session database close: %s", strerror(errno)); 825 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 826 emergency("session database open: %s", strerror(errno)); 827 return (1); 828 } 829 return (0); 830 831 } 832 833 /* 834 * Add a new login session. 835 */ 836 void 837 add_session(sp) 838 session_t *sp; 839 { 840 DBT key; 841 DBT data; 842 843 key.data = &sp->se_process; 844 key.size = sizeof sp->se_process; 845 data.data = &sp; 846 data.size = sizeof sp; 847 848 if ((*session_db->put)(session_db, &key, &data, 0)) 849 emergency("insert %d: %s", sp->se_process, strerror(errno)); 850 } 851 852 /* 853 * Delete an old login session. 854 */ 855 void 856 del_session(sp) 857 session_t *sp; 858 { 859 DBT key; 860 861 key.data = &sp->se_process; 862 key.size = sizeof sp->se_process; 863 864 if ((*session_db->del)(session_db, &key, 0)) 865 emergency("delete %d: %s", sp->se_process, strerror(errno)); 866 } 867 868 /* 869 * Look up a login session by pid. 870 */ 871 session_t * 872 #ifdef __STDC__ 873 find_session(pid_t pid) 874 #else 875 find_session(pid) 876 pid_t pid; 877 #endif 878 { 879 DBT key; 880 DBT data; 881 session_t *ret; 882 883 key.data = &pid; 884 key.size = sizeof pid; 885 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 886 return 0; 887 memmove(&ret, data.data, sizeof(ret)); 888 return ret; 889 } 890 891 /* 892 * Construct an argument vector from a command line. 893 */ 894 char ** 895 construct_argv(command) 896 char *command; 897 { 898 int argc = 0; 899 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 900 * sizeof (char *)); 901 static const char separators[] = " \t"; 902 903 if ((argv[argc++] = strtok(command, separators)) == 0) 904 return (NULL); 905 while ((argv[argc++] = strtok((char *) 0, separators))) 906 continue; 907 return (argv); 908 } 909 910 /* 911 * Deallocate a session descriptor. 912 */ 913 void 914 free_session(sp) 915 session_t *sp; 916 { 917 free(sp->se_device); 918 if (sp->se_getty) { 919 free(sp->se_getty); 920 free(sp->se_getty_argv); 921 } 922 if (sp->se_window) { 923 free(sp->se_window); 924 free(sp->se_window_argv); 925 } 926 free(sp); 927 } 928 929 /* 930 * Allocate a new session descriptor. 931 */ 932 session_t * 933 new_session(sprev, session_index, typ) 934 session_t *sprev; 935 int session_index; 936 struct ttyent *typ; 937 { 938 session_t *sp; 939 940 if ((typ->ty_status & TTY_ON) == 0 || 941 typ->ty_name == NULL || 942 typ->ty_getty == NULL) 943 return (NULL); 944 945 sp = (session_t *) malloc(sizeof (session_t)); 946 memset(sp, 0, sizeof *sp); 947 948 sp->se_flags = SE_PRESENT; 949 sp->se_index = session_index; 950 951 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 952 (void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 953 954 if (setupargv(sp, typ) == 0) { 955 free_session(sp); 956 return (NULL); 957 } 958 959 sp->se_next = NULL; 960 if (sprev == NULL) { 961 sessions = sp; 962 sp->se_prev = NULL; 963 } else { 964 sprev->se_next = sp; 965 sp->se_prev = sprev; 966 } 967 968 return (sp); 969 } 970 971 /* 972 * Calculate getty and if useful window argv vectors. 973 */ 974 int 975 setupargv(sp, typ) 976 session_t *sp; 977 struct ttyent *typ; 978 { 979 980 if (sp->se_getty) { 981 free(sp->se_getty); 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 = construct_argv(sp->se_getty); 987 if (sp->se_getty_argv == NULL) { 988 warning("can't parse getty for port %s", sp->se_device); 989 free(sp->se_getty); 990 sp->se_getty = NULL; 991 return (0); 992 } 993 if (typ->ty_window) { 994 if (sp->se_window) 995 free(sp->se_window); 996 sp->se_window = strdup(typ->ty_window); 997 sp->se_window_argv = construct_argv(sp->se_window); 998 if (sp->se_window_argv == NULL) { 999 warning("can't parse window for port %s", 1000 sp->se_device); 1001 free(sp->se_window); 1002 sp->se_window = NULL; 1003 return (0); 1004 } 1005 } 1006 return (1); 1007 } 1008 1009 /* 1010 * Walk the list of ttys and create sessions for each active line. 1011 */ 1012 state_func_t 1013 read_ttys() 1014 { 1015 int session_index = 0; 1016 session_t *sp, *snext; 1017 struct ttyent *typ; 1018 1019 /* 1020 * Destroy any previous session state. 1021 * There shouldn't be any, but just in case... 1022 */ 1023 for (sp = sessions; sp; sp = snext) { 1024 if (sp->se_process) 1025 clear_session_logs(sp); 1026 snext = sp->se_next; 1027 free_session(sp); 1028 } 1029 sessions = NULL; 1030 if (start_session_db()) 1031 return (state_func_t) single_user; 1032 1033 /* 1034 * Allocate a session entry for each active port. 1035 * Note that sp starts at 0. 1036 */ 1037 while ((typ = getttyent()) != NULL) 1038 if ((snext = new_session(sp, ++session_index, typ)) != NULL) 1039 sp = snext; 1040 1041 endttyent(); 1042 1043 return (state_func_t) multi_user; 1044 } 1045 1046 /* 1047 * Start a window system running. 1048 */ 1049 void 1050 start_window_system(sp) 1051 session_t *sp; 1052 { 1053 pid_t pid; 1054 sigset_t mask; 1055 1056 if ((pid = fork()) == -1) { 1057 emergency("can't fork for window system on port %s: %m", 1058 sp->se_device); 1059 /* hope that getty fails and we can try again */ 1060 return; 1061 } 1062 1063 if (pid) 1064 return; 1065 1066 sigemptyset(&mask); 1067 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1068 1069 if (setsid() < 0) 1070 emergency("setsid failed (window) %m"); 1071 1072 execv(sp->se_window_argv[0], sp->se_window_argv); 1073 stall("can't exec window system '%s' for port %s: %m", 1074 sp->se_window_argv[0], sp->se_device); 1075 _exit(1); 1076 } 1077 1078 /* 1079 * Start a login session running. 1080 */ 1081 pid_t 1082 start_getty(sp) 1083 session_t *sp; 1084 { 1085 pid_t pid; 1086 sigset_t mask; 1087 time_t current_time = time((time_t *) 0); 1088 1089 /* 1090 * fork(), not vfork() -- we can't afford to block. 1091 */ 1092 if ((pid = fork()) == -1) { 1093 emergency("can't fork for getty on port %s: %m", sp->se_device); 1094 return -1; 1095 } 1096 1097 if (pid) 1098 return pid; 1099 1100 if (current_time > sp->se_started && 1101 current_time - sp->se_started < GETTY_SPACING) { 1102 warning("getty repeating too quickly on port %s, sleeping", 1103 sp->se_device); 1104 sleep((unsigned) GETTY_SLEEP); 1105 } 1106 1107 if (sp->se_window) { 1108 start_window_system(sp); 1109 sleep(WINDOW_WAIT); 1110 } 1111 1112 sigemptyset(&mask); 1113 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1114 1115 execv(sp->se_getty_argv[0], sp->se_getty_argv); 1116 stall("can't exec getty '%s' for port %s: %m", 1117 sp->se_getty_argv[0], sp->se_device); 1118 _exit(1); 1119 } 1120 #endif /* LETS_GET_SMALL */ 1121 1122 /* 1123 * Collect exit status for a child. 1124 * If an exiting login, start a new login running. 1125 */ 1126 void 1127 #ifdef __STDC__ 1128 collect_child(pid_t pid) 1129 #else 1130 collect_child(pid) 1131 pid_t pid; 1132 #endif 1133 { 1134 #ifndef LETS_GET_SMALL 1135 session_t *sp, *sprev, *snext; 1136 1137 if (! sessions) 1138 return; 1139 1140 if (! (sp = find_session(pid))) 1141 return; 1142 1143 clear_session_logs(sp); 1144 del_session(sp); 1145 sp->se_process = 0; 1146 1147 if (sp->se_flags & SE_SHUTDOWN) { 1148 if ((sprev = sp->se_prev) != NULL) 1149 sprev->se_next = sp->se_next; 1150 else 1151 sessions = sp->se_next; 1152 if ((snext = sp->se_next) != NULL) 1153 snext->se_prev = sp->se_prev; 1154 free_session(sp); 1155 return; 1156 } 1157 1158 if ((pid = start_getty(sp)) == -1) { 1159 /* serious trouble */ 1160 requested_transition = clean_ttys; 1161 return; 1162 } 1163 1164 sp->se_process = pid; 1165 sp->se_started = time((time_t *) 0); 1166 add_session(sp); 1167 #endif /* LETS_GET_SMALL */ 1168 } 1169 1170 /* 1171 * Catch a signal and request a state transition. 1172 */ 1173 void 1174 transition_handler(sig) 1175 int sig; 1176 { 1177 1178 switch (sig) { 1179 #ifndef LETS_GET_SMALL 1180 case SIGHUP: 1181 requested_transition = clean_ttys; 1182 break; 1183 case SIGTERM: 1184 requested_transition = death; 1185 break; 1186 case SIGTSTP: 1187 requested_transition = catatonia; 1188 break; 1189 #endif /* LETS_GET_SMALL */ 1190 default: 1191 requested_transition = 0; 1192 break; 1193 } 1194 } 1195 1196 #ifndef LETS_GET_SMALL 1197 /* 1198 * Take the system multiuser. 1199 */ 1200 state_func_t 1201 multi_user() 1202 { 1203 pid_t pid; 1204 session_t *sp; 1205 1206 requested_transition = 0; 1207 1208 /* 1209 * If the administrator has not set the security level to -1 1210 * to indicate that the kernel should not run multiuser in secure 1211 * mode, and the run script has not set a higher level of security 1212 * than level 1, then put the kernel into secure mode. 1213 */ 1214 if (getsecuritylevel() == 0) 1215 setsecuritylevel(1); 1216 1217 for (sp = sessions; sp; sp = sp->se_next) { 1218 if (sp->se_process) 1219 continue; 1220 if ((pid = start_getty(sp)) == -1) { 1221 /* serious trouble */ 1222 requested_transition = clean_ttys; 1223 break; 1224 } 1225 sp->se_process = pid; 1226 sp->se_started = time((time_t *) 0); 1227 add_session(sp); 1228 } 1229 1230 while (!requested_transition) 1231 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1232 collect_child(pid); 1233 1234 return (state_func_t) requested_transition; 1235 } 1236 1237 /* 1238 * This is an n-squared algorithm. We hope it isn't run often... 1239 */ 1240 state_func_t 1241 clean_ttys() 1242 { 1243 session_t *sp, *sprev; 1244 struct ttyent *typ; 1245 int session_index = 0; 1246 int devlen; 1247 1248 for (sp = sessions; sp; sp = sp->se_next) 1249 sp->se_flags &= ~SE_PRESENT; 1250 1251 devlen = sizeof(_PATH_DEV) - 1; 1252 while ((typ = getttyent()) != NULL) { 1253 ++session_index; 1254 1255 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1256 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1257 break; 1258 1259 if (sp) { 1260 sp->se_flags |= SE_PRESENT; 1261 if (sp->se_index != session_index) { 1262 warning("port %s changed utmp index from %d to %d", 1263 sp->se_device, sp->se_index, 1264 session_index); 1265 sp->se_index = session_index; 1266 } 1267 if ((typ->ty_status & TTY_ON) == 0 || 1268 typ->ty_getty == 0) { 1269 sp->se_flags |= SE_SHUTDOWN; 1270 kill(sp->se_process, SIGHUP); 1271 continue; 1272 } 1273 sp->se_flags &= ~SE_SHUTDOWN; 1274 if (setupargv(sp, typ) == 0) { 1275 warning("can't parse getty for port %s", 1276 sp->se_device); 1277 sp->se_flags |= SE_SHUTDOWN; 1278 kill(sp->se_process, SIGHUP); 1279 } 1280 continue; 1281 } 1282 1283 new_session(sprev, session_index, typ); 1284 } 1285 1286 endttyent(); 1287 1288 for (sp = sessions; sp; sp = sp->se_next) 1289 if ((sp->se_flags & SE_PRESENT) == 0) { 1290 sp->se_flags |= SE_SHUTDOWN; 1291 kill(sp->se_process, SIGHUP); 1292 } 1293 1294 return (state_func_t) multi_user; 1295 } 1296 1297 /* 1298 * Block further logins. 1299 */ 1300 state_func_t 1301 catatonia() 1302 { 1303 session_t *sp; 1304 1305 for (sp = sessions; sp; sp = sp->se_next) 1306 sp->se_flags |= SE_SHUTDOWN; 1307 1308 return (state_func_t) multi_user; 1309 } 1310 #endif /* LETS_GET_SMALL */ 1311 1312 /* 1313 * Note SIGALRM. 1314 */ 1315 void 1316 alrm_handler(sig) 1317 int sig; 1318 { 1319 clang = 1; 1320 } 1321 1322 #ifndef LETS_GET_SMALL 1323 /* 1324 * Bring the system down to single user. 1325 */ 1326 state_func_t 1327 death() 1328 { 1329 session_t *sp; 1330 int i; 1331 pid_t pid; 1332 static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL }; 1333 1334 for (sp = sessions; sp; sp = sp->se_next) 1335 sp->se_flags |= SE_SHUTDOWN; 1336 1337 /* NB: should send a message to the session logger to avoid blocking. */ 1338 logwtmp("~", "shutdown", ""); 1339 1340 for (i = 0; i < 3; ++i) { 1341 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1342 return (state_func_t) single_user; 1343 1344 clang = 0; 1345 alarm(DEATH_WATCH); 1346 do 1347 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1348 collect_child(pid); 1349 while (clang == 0 && errno != ECHILD); 1350 1351 if (errno == ECHILD) 1352 return (state_func_t) single_user; 1353 } 1354 1355 warning("some processes would not die; ps axl advised"); 1356 1357 return (state_func_t) single_user; 1358 } 1359 #endif /* LETS_GET_SMALL */ 1360 1361 #ifdef MSDOSFS_ROOT 1362 1363 static void 1364 msdosfs_root() 1365 { 1366 /* 1367 * We cannot print errors so we bail out silently... 1368 */ 1369 int fd = -1; 1370 struct stat st; 1371 pid_t pid; 1372 int status; 1373 void *ptr; 1374 struct statfs sfs; 1375 1376 if (statfs("/", &sfs) == -1) 1377 return; 1378 1379 if (strcmp(sfs.f_fstypename, MOUNT_MSDOS) != 0) 1380 return; 1381 1382 /* If we have devices, we cannot be on msdosfs */ 1383 if (access(_PATH_CONSOLE, F_OK) != -1) 1384 return; 1385 1386 /* Grab the contents of MAKEDEV */ 1387 if ((fd = open("/dev/MAKEDEV", O_RDONLY)) == -1) 1388 return; 1389 1390 if (fstat(fd, &st) == -1) 1391 goto done; 1392 1393 if ((ptr = mmap(0, 1394 st.st_size, PROT_READ, MAP_FILE|MAP_SHARED, fd, 0)) == (void *) -1) 1395 goto done; 1396 1397 (void) close(fd); 1398 fd = -1; 1399 1400 /* Mount an mfs over /dev so we can create devices */ 1401 switch ((pid = fork())) { 1402 case 0: 1403 (void) execl("/sbin/mount_mfs", "mount_mfs", "-i", "256", 1404 "-s", "384", "-b", "4096", "-f", "512", "swap", "/dev", 1405 NULL); 1406 goto done; 1407 1408 case -1: 1409 goto done; 1410 1411 default: 1412 if (waitpid(pid, &status, 0) == -1) 1413 goto done; 1414 if (status != 0) 1415 goto done; 1416 break; 1417 } 1418 1419 /* Create a MAKEDEV script in /dev */ 1420 if ((fd = open("/dev/MAKEDEV", O_WRONLY|O_CREAT|O_TRUNC, 0755)) == -1) 1421 goto done; 1422 1423 if (write(fd, ptr, st.st_size) != st.st_size) 1424 goto done; 1425 1426 (void) munmap(ptr, st.st_size); 1427 1428 (void) close(fd); 1429 fd = -1; 1430 1431 #ifdef DEBUG 1432 { 1433 mode_t mode = 0666 | S_IFCHR; 1434 dev_t dev; 1435 #ifdef CPU_CONSDEV 1436 int s = sizeof(dev); 1437 static int name[2] = { CTL_MACHDEP, CPU_CONSDEV }; 1438 1439 if (sysctl(name, sizeof(name) / sizeof(name[0]), &dev, &s, 1440 NULL, 0) == -1) 1441 goto done; 1442 #else 1443 dev = makedev(0, 0); 1444 #endif 1445 1446 /* Make a console for us, so we can see things happening */ 1447 if (mknod(_PATH_CONSOLE, mode, dev) == -1) 1448 goto done; 1449 } 1450 #endif 1451 1452 /* Run the makedev script to create devices */ 1453 switch ((pid = fork())) { 1454 case 0: 1455 if (chdir("/dev") == -1) 1456 goto done; 1457 (void) execl("/bin/sh", "sh", "./MAKEDEV", "all", NULL); 1458 goto done; 1459 1460 case -1: 1461 goto done; 1462 1463 default: 1464 if (waitpid(pid, &status, 0) == -1) 1465 goto done; 1466 if (status != 0) 1467 goto done; 1468 break; 1469 } 1470 1471 done: 1472 if (fd != -1) 1473 (void) close(fd); 1474 } 1475 #endif 1476
Indexes created Fri Sep 26 08:10:20 GMT 2025