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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 static const char copyright[] = 35 "@(#) Copyright (c) 1991, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93"; 42 #endif 43 static const char rcsid[] = 44 "$FreeBSD$"; 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/ioctl.h> 49 #include <sys/mount.h> 50 #include <sys/sysctl.h> 51 #include <sys/wait.h> 52 #include <sys/stat.h> 53 #include <sys/uio.h> 54 55 #include <db.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <kenv.h> 59 #include <libutil.h> 60 #include <paths.h> 61 #include <signal.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <syslog.h> 66 #include <time.h> 67 #include <ttyent.h> 68 #include <unistd.h> 69 #include <utmpx.h> 70 #include <sys/reboot.h> 71 #include <err.h> 72 73 #include <stdarg.h> 74 75 #ifdef SECURE 76 #include <pwd.h> 77 #endif 78 79 #ifdef LOGIN_CAP 80 #include <login_cap.h> 81 #endif 82 83 #include "pathnames.h" 84 85 /* 86 * Sleep times; used to prevent thrashing. 87 */ 88 #define GETTY_SPACING 5 /* N secs minimum getty spacing */ 89 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 90 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ 91 #define WINDOW_WAIT 3 /* wait N secs after starting window */ 92 #define STALL_TIMEOUT 30 /* wait N secs after warning */ 93 #define DEATH_WATCH 10 /* wait N secs for procs to die */ 94 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */ 95 #define RESOURCE_RC "daemon" 96 #define RESOURCE_WINDOW "default" 97 #define RESOURCE_GETTY "default" 98 99 static void handle(sig_t, ...); 100 static void delset(sigset_t *, ...); 101 102 static void stall(const char *, ...) __printflike(1, 2); 103 static void warning(const char *, ...) __printflike(1, 2); 104 static void emergency(const char *, ...) __printflike(1, 2); 105 static void disaster(int); 106 static void badsys(int); 107 static int runshutdown(void); 108 static char *strk(char *); 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 */ 115 typedef long (*state_func_t)(void); 116 typedef state_func_t (*state_t)(void); 117 118 static state_func_t single_user(void); 119 static state_func_t runcom(void); 120 static state_func_t read_ttys(void); 121 static state_func_t multi_user(void); 122 static state_func_t clean_ttys(void); 123 static state_func_t catatonia(void); 124 static state_func_t death(void); 125 static state_func_t death_single(void); 126 127 static state_func_t run_script(const char *); 128 129 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 130 #define FALSE 0 131 #define TRUE 1 132 133 int Reboot = FALSE; 134 int howto = RB_AUTOBOOT; 135 136 int devfs; 137 138 static void transition(state_t); 139 static state_t requested_transition; 140 static state_t current_state = death_single; 141 142 static void setctty(const char *); 143 static const char *get_shell(void); 144 static void write_stderr(const char *message); 145 146 typedef struct init_session { 147 int se_index; /* index of entry in ttys file */ 148 pid_t se_process; /* controlling process */ 149 time_t se_started; /* used to avoid thrashing */ 150 int se_flags; /* status of session */ 151 #define SE_SHUTDOWN 0x1 /* session won't be restarted */ 152 #define SE_PRESENT 0x2 /* session is in /etc/ttys */ 153 int se_nspace; /* spacing count */ 154 char *se_device; /* filename of port */ 155 char *se_getty; /* what to run on that port */ 156 char *se_getty_argv_space; /* pre-parsed argument array space */ 157 char **se_getty_argv; /* pre-parsed argument array */ 158 char *se_window; /* window system (started only once) */ 159 char *se_window_argv_space; /* pre-parsed argument array space */ 160 char **se_window_argv; /* pre-parsed argument array */ 161 char *se_type; /* default terminal type */ 162 struct init_session *se_prev; 163 struct init_session *se_next; 164 } session_t; 165 166 static void free_session(session_t *); 167 static session_t *new_session(session_t *, int, struct ttyent *); 168 static session_t *sessions; 169 170 static char **construct_argv(char *); 171 static void start_window_system(session_t *); 172 static void collect_child(pid_t); 173 static pid_t start_getty(session_t *); 174 static void transition_handler(int); 175 static void alrm_handler(int); 176 static void setsecuritylevel(int); 177 static int getsecuritylevel(void); 178 static int setupargv(session_t *, struct ttyent *); 179 #ifdef LOGIN_CAP 180 static void setprocresources(const char *); 181 #endif 182 static int clang; 183 184 static void clear_session_logs(session_t *); 185 186 static int start_session_db(void); 187 static void add_session(session_t *); 188 static void del_session(session_t *); 189 static session_t *find_session(pid_t); 190 static DB *session_db; 191 192 /* 193 * The mother of all processes. 194 */ 195 int 196 main(int argc, char *argv[]) 197 { 198 state_t initial_transition = runcom; 199 char kenv_value[PATH_MAX]; 200 int c; 201 struct sigaction sa; 202 sigset_t mask; 203 204 /* Dispose of random users. */ 205 if (getuid() != 0) 206 errx(1, "%s", strerror(EPERM)); 207 208 /* System V users like to reexec init. */ 209 if (getpid() != 1) { 210 #ifdef COMPAT_SYSV_INIT 211 /* So give them what they want */ 212 if (argc > 1) { 213 if (strlen(argv[1]) == 1) { 214 char runlevel = *argv[1]; 215 int sig; 216 217 switch (runlevel) { 218 case '0': /* halt + poweroff */ 219 sig = SIGUSR2; 220 break; 221 case '1': /* single-user */ 222 sig = SIGTERM; 223 break; 224 case '6': /* reboot */ 225 sig = SIGINT; 226 break; 227 case 'c': /* block further logins */ 228 sig = SIGTSTP; 229 break; 230 case 'q': /* rescan /etc/ttys */ 231 sig = SIGHUP; 232 break; 233 default: 234 goto invalid; 235 } 236 kill(1, sig); 237 _exit(0); 238 } else 239 invalid: 240 errx(1, "invalid run-level ``%s''", argv[1]); 241 } else 242 #endif 243 errx(1, "already running"); 244 } 245 /* 246 * Note that this does NOT open a file... 247 * Does 'init' deserve its own facility number? 248 */ 249 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH); 250 251 /* 252 * Create an initial session. 253 */ 254 if (setsid() < 0) 255 warning("initial setsid() failed: %m"); 256 257 /* 258 * Establish an initial user so that programs running 259 * single user do not freak out and die (like passwd). 260 */ 261 if (setlogin("root") < 0) 262 warning("setlogin() failed: %m"); 263 264 /* 265 * This code assumes that we always get arguments through flags, 266 * never through bits set in some random machine register. 267 */ 268 while ((c = getopt(argc, argv, "dsf")) != -1) 269 switch (c) { 270 case 'd': 271 devfs = 1; 272 break; 273 case 's': 274 initial_transition = single_user; 275 break; 276 case 'f': 277 runcom_mode = FASTBOOT; 278 break; 279 default: 280 warning("unrecognized flag '-%c'", c); 281 break; 282 } 283 284 if (optind != argc) 285 warning("ignoring excess arguments"); 286 287 /* 288 * We catch or block signals rather than ignore them, 289 * so that they get reset on exec. 290 */ 291 handle(badsys, SIGSYS, 0); 292 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 293 SIGXFSZ, 0); 294 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGUSR1, 295 SIGUSR2, 0); 296 handle(alrm_handler, SIGALRM, 0); 297 sigfillset(&mask); 298 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 299 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM, 300 SIGUSR1, SIGUSR2, 0); 301 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 302 sigemptyset(&sa.sa_mask); 303 sa.sa_flags = 0; 304 sa.sa_handler = SIG_IGN; 305 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 306 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 307 308 /* 309 * Paranoia. 310 */ 311 close(0); 312 close(1); 313 close(2); 314 315 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 316 state_func_t next_transition; 317 318 if ((next_transition = run_script(kenv_value)) != 0) 319 initial_transition = (state_t) next_transition; 320 } 321 322 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 323 if (chdir(kenv_value) != 0 || chroot(".") != 0) 324 warning("Can't chroot to %s: %m", kenv_value); 325 } 326 327 /* 328 * Additional check if devfs needs to be mounted: 329 * If "/" and "/dev" have the same device number, 330 * then it hasn't been mounted yet. 331 */ 332 if (!devfs) { 333 struct stat stst; 334 dev_t root_devno; 335 336 stat("/", &stst); 337 root_devno = stst.st_dev; 338 if (stat("/dev", &stst) != 0) 339 warning("Can't stat /dev: %m"); 340 else if (stst.st_dev == root_devno) 341 devfs++; 342 } 343 344 if (devfs) { 345 struct iovec iov[4]; 346 char *s; 347 int i; 348 349 char _fstype[] = "fstype"; 350 char _devfs[] = "devfs"; 351 char _fspath[] = "fspath"; 352 char _path_dev[]= _PATH_DEV; 353 354 iov[0].iov_base = _fstype; 355 iov[0].iov_len = sizeof(_fstype); 356 iov[1].iov_base = _devfs; 357 iov[1].iov_len = sizeof(_devfs); 358 iov[2].iov_base = _fspath; 359 iov[2].iov_len = sizeof(_fspath); 360 /* 361 * Try to avoid the trailing slash in _PATH_DEV. 362 * Be *very* defensive. 363 */ 364 s = strdup(_PATH_DEV); 365 if (s != NULL) { 366 i = strlen(s); 367 if (i > 0 && s[i - 1] == '/') 368 s[i - 1] = '\0'; 369 iov[3].iov_base = s; 370 iov[3].iov_len = strlen(s) + 1; 371 } else { 372 iov[3].iov_base = _path_dev; 373 iov[3].iov_len = sizeof(_path_dev); 374 } 375 nmount(iov, 4, 0); 376 if (s != NULL) 377 free(s); 378 } 379 380 /* 381 * Start the state machine. 382 */ 383 transition(initial_transition); 384 385 /* 386 * Should never reach here. 387 */ 388 return 1; 389 } 390 391 /* 392 * Associate a function with a signal handler. 393 */ 394 static void 395 handle(sig_t handler, ...) 396 { 397 int sig; 398 struct sigaction sa; 399 sigset_t mask_everything; 400 va_list ap; 401 va_start(ap, handler); 402 403 sa.sa_handler = handler; 404 sigfillset(&mask_everything); 405 406 while ((sig = va_arg(ap, int)) != 0) { 407 sa.sa_mask = mask_everything; 408 /* XXX SA_RESTART? */ 409 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 410 sigaction(sig, &sa, (struct sigaction *) 0); 411 } 412 va_end(ap); 413 } 414 415 /* 416 * Delete a set of signals from a mask. 417 */ 418 static void 419 delset(sigset_t *maskp, ...) 420 { 421 int sig; 422 va_list ap; 423 va_start(ap, maskp); 424 425 while ((sig = va_arg(ap, int)) != 0) 426 sigdelset(maskp, sig); 427 va_end(ap); 428 } 429 430 /* 431 * Log a message and sleep for a while (to give someone an opportunity 432 * to read it and to save log or hardcopy output if the problem is chronic). 433 * NB: should send a message to the session logger to avoid blocking. 434 */ 435 static void 436 stall(const char *message, ...) 437 { 438 va_list ap; 439 va_start(ap, message); 440 441 vsyslog(LOG_ALERT, message, ap); 442 va_end(ap); 443 sleep(STALL_TIMEOUT); 444 } 445 446 /* 447 * Like stall(), but doesn't sleep. 448 * If cpp had variadic macros, the two functions could be #defines for another. 449 * NB: should send a message to the session logger to avoid blocking. 450 */ 451 static void 452 warning(const char *message, ...) 453 { 454 va_list ap; 455 va_start(ap, message); 456 457 vsyslog(LOG_ALERT, message, ap); 458 va_end(ap); 459 } 460 461 /* 462 * Log an emergency message. 463 * NB: should send a message to the session logger to avoid blocking. 464 */ 465 static void 466 emergency(const char *message, ...) 467 { 468 va_list ap; 469 va_start(ap, message); 470 471 vsyslog(LOG_EMERG, message, ap); 472 va_end(ap); 473 } 474 475 /* 476 * Catch a SIGSYS signal. 477 * 478 * These may arise if a system does not support sysctl. 479 * We tolerate up to 25 of these, then throw in the towel. 480 */ 481 static void 482 badsys(int sig) 483 { 484 static int badcount = 0; 485 486 if (badcount++ < 25) 487 return; 488 disaster(sig); 489 } 490 491 /* 492 * Catch an unexpected signal. 493 */ 494 static void 495 disaster(int sig) 496 { 497 498 emergency("fatal signal: %s", 499 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 500 501 sleep(STALL_TIMEOUT); 502 _exit(sig); /* reboot */ 503 } 504 505 /* 506 * Get the security level of the kernel. 507 */ 508 static int 509 getsecuritylevel(void) 510 { 511 #ifdef KERN_SECURELVL 512 int name[2], curlevel; 513 size_t len; 514 515 name[0] = CTL_KERN; 516 name[1] = KERN_SECURELVL; 517 len = sizeof curlevel; 518 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 519 emergency("cannot get kernel security level: %s", 520 strerror(errno)); 521 return (-1); 522 } 523 return (curlevel); 524 #else 525 return (-1); 526 #endif 527 } 528 529 /* 530 * Set the security level of the kernel. 531 */ 532 static void 533 setsecuritylevel(int newlevel) 534 { 535 #ifdef KERN_SECURELVL 536 int name[2], curlevel; 537 538 curlevel = getsecuritylevel(); 539 if (newlevel == curlevel) 540 return; 541 name[0] = CTL_KERN; 542 name[1] = KERN_SECURELVL; 543 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 544 emergency( 545 "cannot change kernel security level from %d to %d: %s", 546 curlevel, newlevel, strerror(errno)); 547 return; 548 } 549 #ifdef SECURE 550 warning("kernel security level changed from %d to %d", 551 curlevel, newlevel); 552 #endif 553 #endif 554 } 555 556 /* 557 * Change states in the finite state machine. 558 * The initial state is passed as an argument. 559 */ 560 static void 561 transition(state_t s) 562 { 563 564 current_state = s; 565 for (;;) 566 current_state = (state_t) (*current_state)(); 567 } 568 569 /* 570 * Close out the accounting files for a login session. 571 * NB: should send a message to the session logger to avoid blocking. 572 */ 573 static void 574 clear_session_logs(session_t *sp __unused) 575 { 576 577 /* 578 * XXX: Use getutxline() and call pututxline() for each entry. 579 * Is this safe to do this here? Is it really required anyway? 580 */ 581 } 582 583 /* 584 * Start a session and allocate a controlling terminal. 585 * Only called by children of init after forking. 586 */ 587 static void 588 setctty(const char *name) 589 { 590 int fd; 591 592 revoke(name); 593 if ((fd = open(name, O_RDWR)) == -1) { 594 stall("can't open %s: %m", name); 595 _exit(1); 596 } 597 if (login_tty(fd) == -1) { 598 stall("can't get %s for controlling terminal: %m", name); 599 _exit(1); 600 } 601 } 602 603 static const char * 604 get_shell(void) 605 { 606 static char kenv_value[PATH_MAX]; 607 608 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 609 return kenv_value; 610 else 611 return _PATH_BSHELL; 612 } 613 614 static void 615 write_stderr(const char *message) 616 { 617 618 write(STDERR_FILENO, message, strlen(message)); 619 } 620 621 /* 622 * Bring the system up single user. 623 */ 624 static state_func_t 625 single_user(void) 626 { 627 pid_t pid, wpid; 628 int status; 629 sigset_t mask; 630 const char *shell; 631 char *argv[2]; 632 #ifdef SECURE 633 struct ttyent *typ; 634 struct passwd *pp; 635 static const char banner[] = 636 "Enter root password, or ^D to go multi-user\n"; 637 char *clear, *password; 638 #endif 639 #ifdef DEBUGSHELL 640 char altshell[128]; 641 #endif 642 643 if (Reboot) { 644 /* Instead of going single user, let's reboot the machine */ 645 sync(); 646 alarm(2); 647 pause(); 648 reboot(howto); 649 _exit(0); 650 } 651 652 shell = get_shell(); 653 654 if ((pid = fork()) == 0) { 655 /* 656 * Start the single user session. 657 */ 658 setctty(_PATH_CONSOLE); 659 660 #ifdef SECURE 661 /* 662 * Check the root password. 663 * We don't care if the console is 'on' by default; 664 * it's the only tty that can be 'off' and 'secure'. 665 */ 666 typ = getttynam("console"); 667 pp = getpwnam("root"); 668 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 669 pp && *pp->pw_passwd) { 670 write_stderr(banner); 671 for (;;) { 672 clear = getpass("Password:"); 673 if (clear == 0 || *clear == '\0') 674 _exit(0); 675 password = crypt(clear, pp->pw_passwd); 676 bzero(clear, _PASSWORD_LEN); 677 if (strcmp(password, pp->pw_passwd) == 0) 678 break; 679 warning("single-user login failed\n"); 680 } 681 } 682 endttyent(); 683 endpwent(); 684 #endif /* SECURE */ 685 686 #ifdef DEBUGSHELL 687 { 688 char *cp = altshell; 689 int num; 690 691 #define SHREQUEST "Enter full pathname of shell or RETURN for " 692 write_stderr(SHREQUEST); 693 write_stderr(shell); 694 write_stderr(": "); 695 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 696 num != 0 && *cp != '\n' && cp < &altshell[127]) 697 cp++; 698 *cp = '\0'; 699 if (altshell[0] != '\0') 700 shell = altshell; 701 } 702 #endif /* DEBUGSHELL */ 703 704 /* 705 * Unblock signals. 706 * We catch all the interesting ones, 707 * and those are reset to SIG_DFL on exec. 708 */ 709 sigemptyset(&mask); 710 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 711 712 /* 713 * Fire off a shell. 714 * If the default one doesn't work, try the Bourne shell. 715 */ 716 717 char name[] = "-sh"; 718 719 argv[0] = name; 720 argv[1] = 0; 721 execv(shell, argv); 722 emergency("can't exec %s for single user: %m", shell); 723 execv(_PATH_BSHELL, argv); 724 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 725 sleep(STALL_TIMEOUT); 726 _exit(1); 727 } 728 729 if (pid == -1) { 730 /* 731 * We are seriously hosed. Do our best. 732 */ 733 emergency("can't fork single-user shell, trying again"); 734 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 735 continue; 736 return (state_func_t) single_user; 737 } 738 739 requested_transition = 0; 740 do { 741 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 742 collect_child(wpid); 743 if (wpid == -1) { 744 if (errno == EINTR) 745 continue; 746 warning("wait for single-user shell failed: %m; restarting"); 747 return (state_func_t) single_user; 748 } 749 if (wpid == pid && WIFSTOPPED(status)) { 750 warning("init: shell stopped, restarting\n"); 751 kill(pid, SIGCONT); 752 wpid = -1; 753 } 754 } while (wpid != pid && !requested_transition); 755 756 if (requested_transition) 757 return (state_func_t) requested_transition; 758 759 if (!WIFEXITED(status)) { 760 if (WTERMSIG(status) == SIGKILL) { 761 /* 762 * reboot(8) killed shell? 763 */ 764 warning("single user shell terminated."); 765 sleep(STALL_TIMEOUT); 766 _exit(0); 767 } else { 768 warning("single user shell terminated, restarting"); 769 return (state_func_t) single_user; 770 } 771 } 772 773 runcom_mode = FASTBOOT; 774 return (state_func_t) runcom; 775 } 776 777 /* 778 * Run the system startup script. 779 */ 780 static state_func_t 781 runcom(void) 782 { 783 struct utmpx utx; 784 state_func_t next_transition; 785 786 if ((next_transition = run_script(_PATH_RUNCOM)) != 0) 787 return next_transition; 788 789 runcom_mode = AUTOBOOT; /* the default */ 790 /* NB: should send a message to the session logger to avoid blocking. */ 791 utx.ut_type = BOOT_TIME; 792 gettimeofday(&utx.ut_tv, NULL); 793 pututxline(&utx); 794 return (state_func_t) read_ttys; 795 } 796 797 /* 798 * Run a shell script. 799 * Returns 0 on success, otherwise the next transition to enter: 800 * - single_user if fork/execv/waitpid failed, or if the script 801 * terminated with a signal or exit code != 0. 802 * - death_single if a SIGTERM was delivered to init(8). 803 */ 804 static state_func_t 805 run_script(const char *script) 806 { 807 pid_t pid, wpid; 808 int status; 809 char *argv[4]; 810 const char *shell; 811 struct sigaction sa; 812 813 shell = get_shell(); 814 815 if ((pid = fork()) == 0) { 816 sigemptyset(&sa.sa_mask); 817 sa.sa_flags = 0; 818 sa.sa_handler = SIG_IGN; 819 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 820 sigaction(SIGHUP, &sa, (struct sigaction *)0); 821 822 setctty(_PATH_CONSOLE); 823 824 char _sh[] = "sh"; 825 char _autoboot[] = "autoboot"; 826 827 argv[0] = _sh; 828 argv[1] = __DECONST(char *, script); 829 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 830 argv[3] = 0; 831 832 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 833 834 #ifdef LOGIN_CAP 835 setprocresources(RESOURCE_RC); 836 #endif 837 execv(shell, argv); 838 stall("can't exec %s for %s: %m", shell, script); 839 _exit(1); /* force single user mode */ 840 } 841 842 if (pid == -1) { 843 emergency("can't fork for %s on %s: %m", shell, script); 844 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 845 continue; 846 sleep(STALL_TIMEOUT); 847 return (state_func_t) single_user; 848 } 849 850 /* 851 * Copied from single_user(). This is a bit paranoid. 852 */ 853 requested_transition = 0; 854 do { 855 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 856 collect_child(wpid); 857 if (wpid == -1) { 858 if (requested_transition == death_single) 859 return (state_func_t) death_single; 860 if (errno == EINTR) 861 continue; 862 warning("wait for %s on %s failed: %m; going to " 863 "single user mode", shell, script); 864 return (state_func_t) single_user; 865 } 866 if (wpid == pid && WIFSTOPPED(status)) { 867 warning("init: %s on %s stopped, restarting\n", 868 shell, script); 869 kill(pid, SIGCONT); 870 wpid = -1; 871 } 872 } while (wpid != pid); 873 874 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 875 requested_transition == catatonia) { 876 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 877 sigset_t s; 878 879 sigfillset(&s); 880 for (;;) 881 sigsuspend(&s); 882 } 883 884 if (!WIFEXITED(status)) { 885 warning("%s on %s terminated abnormally, going to single " 886 "user mode", shell, script); 887 return (state_func_t) single_user; 888 } 889 890 if (WEXITSTATUS(status)) 891 return (state_func_t) single_user; 892 893 return (state_func_t) 0; 894 } 895 896 /* 897 * Open the session database. 898 * 899 * NB: We could pass in the size here; is it necessary? 900 */ 901 static int 902 start_session_db(void) 903 { 904 if (session_db && (*session_db->close)(session_db)) 905 emergency("session database close: %s", strerror(errno)); 906 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 907 emergency("session database open: %s", strerror(errno)); 908 return (1); 909 } 910 return (0); 911 912 } 913 914 /* 915 * Add a new login session. 916 */ 917 static void 918 add_session(session_t *sp) 919 { 920 DBT key; 921 DBT data; 922 923 key.data = &sp->se_process; 924 key.size = sizeof sp->se_process; 925 data.data = &sp; 926 data.size = sizeof sp; 927 928 if ((*session_db->put)(session_db, &key, &data, 0)) 929 emergency("insert %d: %s", sp->se_process, strerror(errno)); 930 } 931 932 /* 933 * Delete an old login session. 934 */ 935 static void 936 del_session(session_t *sp) 937 { 938 DBT key; 939 940 key.data = &sp->se_process; 941 key.size = sizeof sp->se_process; 942 943 if ((*session_db->del)(session_db, &key, 0)) 944 emergency("delete %d: %s", sp->se_process, strerror(errno)); 945 } 946 947 /* 948 * Look up a login session by pid. 949 */ 950 static session_t * 951 find_session(pid_t pid) 952 { 953 DBT key; 954 DBT data; 955 session_t *ret; 956 957 key.data = &pid; 958 key.size = sizeof pid; 959 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 960 return 0; 961 bcopy(data.data, (char *)&ret, sizeof(ret)); 962 return ret; 963 } 964 965 /* 966 * Construct an argument vector from a command line. 967 */ 968 static char ** 969 construct_argv(char *command) 970 { 971 int argc = 0; 972 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 973 * sizeof (char *)); 974 975 if ((argv[argc++] = strk(command)) == 0) { 976 free(argv); 977 return (NULL); 978 } 979 while ((argv[argc++] = strk((char *) 0)) != NULL) 980 continue; 981 return argv; 982 } 983 984 /* 985 * Deallocate a session descriptor. 986 */ 987 static void 988 free_session(session_t *sp) 989 { 990 free(sp->se_device); 991 if (sp->se_getty) { 992 free(sp->se_getty); 993 free(sp->se_getty_argv_space); 994 free(sp->se_getty_argv); 995 } 996 if (sp->se_window) { 997 free(sp->se_window); 998 free(sp->se_window_argv_space); 999 free(sp->se_window_argv); 1000 } 1001 if (sp->se_type) 1002 free(sp->se_type); 1003 free(sp); 1004 } 1005 1006 /* 1007 * Allocate a new session descriptor. 1008 * Mark it SE_PRESENT. 1009 */ 1010 static session_t * 1011 new_session(session_t *sprev, int session_index, struct ttyent *typ) 1012 { 1013 session_t *sp; 1014 int fd; 1015 1016 if ((typ->ty_status & TTY_ON) == 0 || 1017 typ->ty_name == 0 || 1018 typ->ty_getty == 0) 1019 return 0; 1020 1021 sp = (session_t *) calloc(1, sizeof (session_t)); 1022 1023 sp->se_index = session_index; 1024 sp->se_flags |= SE_PRESENT; 1025 1026 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 1027 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 1028 1029 /* 1030 * Attempt to open the device, if we get "device not configured" 1031 * then don't add the device to the session list. 1032 */ 1033 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) { 1034 if (errno == ENXIO) { 1035 free_session(sp); 1036 return (0); 1037 } 1038 } else 1039 close(fd); 1040 1041 if (setupargv(sp, typ) == 0) { 1042 free_session(sp); 1043 return (0); 1044 } 1045 1046 sp->se_next = 0; 1047 if (sprev == 0) { 1048 sessions = sp; 1049 sp->se_prev = 0; 1050 } else { 1051 sprev->se_next = sp; 1052 sp->se_prev = sprev; 1053 } 1054 1055 return sp; 1056 } 1057 1058 /* 1059 * Calculate getty and if useful window argv vectors. 1060 */ 1061 static int 1062 setupargv(session_t *sp, struct ttyent *typ) 1063 { 1064 1065 if (sp->se_getty) { 1066 free(sp->se_getty); 1067 free(sp->se_getty_argv_space); 1068 free(sp->se_getty_argv); 1069 } 1070 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 1071 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 1072 sp->se_getty_argv_space = strdup(sp->se_getty); 1073 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1074 if (sp->se_getty_argv == 0) { 1075 warning("can't parse getty for port %s", sp->se_device); 1076 free(sp->se_getty); 1077 free(sp->se_getty_argv_space); 1078 sp->se_getty = sp->se_getty_argv_space = 0; 1079 return (0); 1080 } 1081 if (sp->se_window) { 1082 free(sp->se_window); 1083 free(sp->se_window_argv_space); 1084 free(sp->se_window_argv); 1085 } 1086 sp->se_window = sp->se_window_argv_space = 0; 1087 sp->se_window_argv = 0; 1088 if (typ->ty_window) { 1089 sp->se_window = strdup(typ->ty_window); 1090 sp->se_window_argv_space = strdup(sp->se_window); 1091 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1092 if (sp->se_window_argv == 0) { 1093 warning("can't parse window for port %s", 1094 sp->se_device); 1095 free(sp->se_window_argv_space); 1096 free(sp->se_window); 1097 sp->se_window = sp->se_window_argv_space = 0; 1098 return (0); 1099 } 1100 } 1101 if (sp->se_type) 1102 free(sp->se_type); 1103 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1104 return (1); 1105 } 1106 1107 /* 1108 * Walk the list of ttys and create sessions for each active line. 1109 */ 1110 static state_func_t 1111 read_ttys(void) 1112 { 1113 int session_index = 0; 1114 session_t *sp, *snext; 1115 struct ttyent *typ; 1116 1117 /* 1118 * Destroy any previous session state. 1119 * There shouldn't be any, but just in case... 1120 */ 1121 for (sp = sessions; sp; sp = snext) { 1122 if (sp->se_process) 1123 clear_session_logs(sp); 1124 snext = sp->se_next; 1125 free_session(sp); 1126 } 1127 sessions = 0; 1128 if (start_session_db()) 1129 return (state_func_t) single_user; 1130 1131 /* 1132 * Allocate a session entry for each active port. 1133 * Note that sp starts at 0. 1134 */ 1135 while ((typ = getttyent()) != NULL) 1136 if ((snext = new_session(sp, ++session_index, typ)) != NULL) 1137 sp = snext; 1138 1139 endttyent(); 1140 1141 return (state_func_t) multi_user; 1142 } 1143 1144 /* 1145 * Start a window system running. 1146 */ 1147 static void 1148 start_window_system(session_t *sp) 1149 { 1150 pid_t pid; 1151 sigset_t mask; 1152 char term[64], *env[2]; 1153 int status; 1154 1155 if ((pid = fork()) == -1) { 1156 emergency("can't fork for window system on port %s: %m", 1157 sp->se_device); 1158 /* hope that getty fails and we can try again */ 1159 return; 1160 } 1161 if (pid) { 1162 waitpid(-1, &status, 0); 1163 return; 1164 } 1165 1166 /* reparent window process to the init to not make a zombie on exit */ 1167 if ((pid = fork()) == -1) { 1168 emergency("can't fork for window system on port %s: %m", 1169 sp->se_device); 1170 _exit(1); 1171 } 1172 if (pid) 1173 _exit(0); 1174 1175 sigemptyset(&mask); 1176 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1177 1178 if (setsid() < 0) 1179 emergency("setsid failed (window) %m"); 1180 1181 #ifdef LOGIN_CAP 1182 setprocresources(RESOURCE_WINDOW); 1183 #endif 1184 if (sp->se_type) { 1185 /* Don't use malloc after fork */ 1186 strcpy(term, "TERM="); 1187 strncat(term, sp->se_type, sizeof(term) - 6); 1188 env[0] = term; 1189 env[1] = 0; 1190 } 1191 else 1192 env[0] = 0; 1193 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1194 stall("can't exec window system '%s' for port %s: %m", 1195 sp->se_window_argv[0], sp->se_device); 1196 _exit(1); 1197 } 1198 1199 /* 1200 * Start a login session running. 1201 */ 1202 static pid_t 1203 start_getty(session_t *sp) 1204 { 1205 pid_t pid; 1206 sigset_t mask; 1207 time_t current_time = time((time_t *) 0); 1208 int too_quick = 0; 1209 char term[64], *env[2]; 1210 1211 if (current_time >= sp->se_started && 1212 current_time - sp->se_started < GETTY_SPACING) { 1213 if (++sp->se_nspace > GETTY_NSPACE) { 1214 sp->se_nspace = 0; 1215 too_quick = 1; 1216 } 1217 } else 1218 sp->se_nspace = 0; 1219 1220 /* 1221 * fork(), not vfork() -- we can't afford to block. 1222 */ 1223 if ((pid = fork()) == -1) { 1224 emergency("can't fork for getty on port %s: %m", sp->se_device); 1225 return -1; 1226 } 1227 1228 if (pid) 1229 return pid; 1230 1231 if (too_quick) { 1232 warning("getty repeating too quickly on port %s, sleeping %d secs", 1233 sp->se_device, GETTY_SLEEP); 1234 sleep((unsigned) GETTY_SLEEP); 1235 } 1236 1237 if (sp->se_window) { 1238 start_window_system(sp); 1239 sleep(WINDOW_WAIT); 1240 } 1241 1242 sigemptyset(&mask); 1243 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1244 1245 #ifdef LOGIN_CAP 1246 setprocresources(RESOURCE_GETTY); 1247 #endif 1248 if (sp->se_type) { 1249 /* Don't use malloc after fork */ 1250 strcpy(term, "TERM="); 1251 strncat(term, sp->se_type, sizeof(term) - 6); 1252 env[0] = term; 1253 env[1] = 0; 1254 } else 1255 env[0] = 0; 1256 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1257 stall("can't exec getty '%s' for port %s: %m", 1258 sp->se_getty_argv[0], sp->se_device); 1259 _exit(1); 1260 } 1261 1262 /* 1263 * Collect exit status for a child. 1264 * If an exiting login, start a new login running. 1265 */ 1266 static void 1267 collect_child(pid_t pid) 1268 { 1269 session_t *sp, *sprev, *snext; 1270 1271 if (! sessions) 1272 return; 1273 1274 if (! (sp = find_session(pid))) 1275 return; 1276 1277 clear_session_logs(sp); 1278 del_session(sp); 1279 sp->se_process = 0; 1280 1281 if (sp->se_flags & SE_SHUTDOWN) { 1282 if ((sprev = sp->se_prev) != NULL) 1283 sprev->se_next = sp->se_next; 1284 else 1285 sessions = sp->se_next; 1286 if ((snext = sp->se_next) != NULL) 1287 snext->se_prev = sp->se_prev; 1288 free_session(sp); 1289 return; 1290 } 1291 1292 if ((pid = start_getty(sp)) == -1) { 1293 /* serious trouble */ 1294 requested_transition = clean_ttys; 1295 return; 1296 } 1297 1298 sp->se_process = pid; 1299 sp->se_started = time((time_t *) 0); 1300 add_session(sp); 1301 } 1302 1303 /* 1304 * Catch a signal and request a state transition. 1305 */ 1306 static void 1307 transition_handler(int sig) 1308 { 1309 1310 switch (sig) { 1311 case SIGHUP: 1312 if (current_state == read_ttys || current_state == multi_user || 1313 current_state == clean_ttys || current_state == catatonia) 1314 requested_transition = clean_ttys; 1315 break; 1316 case SIGUSR2: 1317 howto = RB_POWEROFF; 1318 case SIGUSR1: 1319 howto |= RB_HALT; 1320 case SIGINT: 1321 Reboot = TRUE; 1322 case SIGTERM: 1323 if (current_state == read_ttys || current_state == multi_user || 1324 current_state == clean_ttys || current_state == catatonia) 1325 requested_transition = death; 1326 else 1327 requested_transition = death_single; 1328 break; 1329 case SIGTSTP: 1330 if (current_state == runcom || current_state == read_ttys || 1331 current_state == clean_ttys || 1332 current_state == multi_user || current_state == catatonia) 1333 requested_transition = catatonia; 1334 break; 1335 default: 1336 requested_transition = 0; 1337 break; 1338 } 1339 } 1340 1341 /* 1342 * Take the system multiuser. 1343 */ 1344 static state_func_t 1345 multi_user(void) 1346 { 1347 pid_t pid; 1348 session_t *sp; 1349 1350 requested_transition = 0; 1351 1352 /* 1353 * If the administrator has not set the security level to -1 1354 * to indicate that the kernel should not run multiuser in secure 1355 * mode, and the run script has not set a higher level of security 1356 * than level 1, then put the kernel into secure mode. 1357 */ 1358 if (getsecuritylevel() == 0) 1359 setsecuritylevel(1); 1360 1361 for (sp = sessions; sp; sp = sp->se_next) { 1362 if (sp->se_process) 1363 continue; 1364 if ((pid = start_getty(sp)) == -1) { 1365 /* serious trouble */ 1366 requested_transition = clean_ttys; 1367 break; 1368 } 1369 sp->se_process = pid; 1370 sp->se_started = time((time_t *) 0); 1371 add_session(sp); 1372 } 1373 1374 while (!requested_transition) 1375 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1376 collect_child(pid); 1377 1378 return (state_func_t) requested_transition; 1379 } 1380 1381 /* 1382 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1383 */ 1384 static state_func_t 1385 clean_ttys(void) 1386 { 1387 session_t *sp, *sprev; 1388 struct ttyent *typ; 1389 int session_index = 0; 1390 int devlen; 1391 char *old_getty, *old_window, *old_type; 1392 1393 /* 1394 * mark all sessions for death, (!SE_PRESENT) 1395 * as we find or create new ones they'll be marked as keepers, 1396 * we'll later nuke all the ones not found in /etc/ttys 1397 */ 1398 for (sp = sessions; sp != NULL; sp = sp->se_next) 1399 sp->se_flags &= ~SE_PRESENT; 1400 1401 devlen = sizeof(_PATH_DEV) - 1; 1402 while ((typ = getttyent()) != NULL) { 1403 ++session_index; 1404 1405 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1406 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1407 break; 1408 1409 if (sp) { 1410 /* we want this one to live */ 1411 sp->se_flags |= SE_PRESENT; 1412 if (sp->se_index != session_index) { 1413 warning("port %s changed utmp index from %d to %d", 1414 sp->se_device, sp->se_index, 1415 session_index); 1416 sp->se_index = session_index; 1417 } 1418 if ((typ->ty_status & TTY_ON) == 0 || 1419 typ->ty_getty == 0) { 1420 sp->se_flags |= SE_SHUTDOWN; 1421 kill(sp->se_process, SIGHUP); 1422 continue; 1423 } 1424 sp->se_flags &= ~SE_SHUTDOWN; 1425 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1426 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1427 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1428 if (setupargv(sp, typ) == 0) { 1429 warning("can't parse getty for port %s", 1430 sp->se_device); 1431 sp->se_flags |= SE_SHUTDOWN; 1432 kill(sp->se_process, SIGHUP); 1433 } 1434 else if ( !old_getty 1435 || (!old_type && sp->se_type) 1436 || (old_type && !sp->se_type) 1437 || (!old_window && sp->se_window) 1438 || (old_window && !sp->se_window) 1439 || (strcmp(old_getty, sp->se_getty) != 0) 1440 || (old_window && strcmp(old_window, sp->se_window) != 0) 1441 || (old_type && strcmp(old_type, sp->se_type) != 0) 1442 ) { 1443 /* Don't set SE_SHUTDOWN here */ 1444 sp->se_nspace = 0; 1445 sp->se_started = 0; 1446 kill(sp->se_process, SIGHUP); 1447 } 1448 if (old_getty) 1449 free(old_getty); 1450 if (old_window) 1451 free(old_window); 1452 if (old_type) 1453 free(old_type); 1454 continue; 1455 } 1456 1457 new_session(sprev, session_index, typ); 1458 } 1459 1460 endttyent(); 1461 1462 /* 1463 * sweep through and kill all deleted sessions 1464 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1465 */ 1466 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1467 if ((sp->se_flags & SE_PRESENT) == 0) { 1468 sp->se_flags |= SE_SHUTDOWN; 1469 kill(sp->se_process, SIGHUP); 1470 } 1471 } 1472 1473 return (state_func_t) multi_user; 1474 } 1475 1476 /* 1477 * Block further logins. 1478 */ 1479 static state_func_t 1480 catatonia(void) 1481 { 1482 session_t *sp; 1483 1484 for (sp = sessions; sp; sp = sp->se_next) 1485 sp->se_flags |= SE_SHUTDOWN; 1486 1487 return (state_func_t) multi_user; 1488 } 1489 1490 /* 1491 * Note SIGALRM. 1492 */ 1493 static void 1494 alrm_handler(int sig) 1495 { 1496 1497 (void)sig; 1498 clang = 1; 1499 } 1500 1501 /* 1502 * Bring the system down to single user. 1503 */ 1504 static state_func_t 1505 death(void) 1506 { 1507 struct utmpx utx; 1508 session_t *sp; 1509 1510 /* NB: should send a message to the session logger to avoid blocking. */ 1511 utx.ut_type = SHUTDOWN_TIME; 1512 gettimeofday(&utx.ut_tv, NULL); 1513 pututxline(&utx); 1514 1515 /* 1516 * Also revoke the TTY here. Because runshutdown() may reopen 1517 * the TTY whose getty we're killing here, there is no guarantee 1518 * runshutdown() will perform the initial open() call, causing 1519 * the terminal attributes to be misconfigured. 1520 */ 1521 for (sp = sessions; sp; sp = sp->se_next) { 1522 sp->se_flags |= SE_SHUTDOWN; 1523 kill(sp->se_process, SIGHUP); 1524 revoke(sp->se_device); 1525 } 1526 1527 /* Try to run the rc.shutdown script within a period of time */ 1528 runshutdown(); 1529 1530 return (state_func_t) death_single; 1531 } 1532 1533 /* 1534 * Do what is necessary to reinitialize single user mode or reboot 1535 * from an incomplete state. 1536 */ 1537 static state_func_t 1538 death_single(void) 1539 { 1540 int i; 1541 pid_t pid; 1542 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1543 1544 revoke(_PATH_CONSOLE); 1545 1546 for (i = 0; i < 2; ++i) { 1547 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1548 return (state_func_t) single_user; 1549 1550 clang = 0; 1551 alarm(DEATH_WATCH); 1552 do 1553 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1554 collect_child(pid); 1555 while (clang == 0 && errno != ECHILD); 1556 1557 if (errno == ECHILD) 1558 return (state_func_t) single_user; 1559 } 1560 1561 warning("some processes would not die; ps axl advised"); 1562 1563 return (state_func_t) single_user; 1564 } 1565 1566 /* 1567 * Run the system shutdown script. 1568 * 1569 * Exit codes: XXX I should document more 1570 * -2 shutdown script terminated abnormally 1571 * -1 fatal error - can't run script 1572 * 0 good. 1573 * >0 some error (exit code) 1574 */ 1575 static int 1576 runshutdown(void) 1577 { 1578 pid_t pid, wpid; 1579 int status; 1580 int shutdowntimeout; 1581 size_t len; 1582 char *argv[4]; 1583 const char *shell; 1584 struct sigaction sa; 1585 struct stat sb; 1586 1587 /* 1588 * rc.shutdown is optional, so to prevent any unnecessary 1589 * complaints from the shell we simply don't run it if the 1590 * file does not exist. If the stat() here fails for other 1591 * reasons, we'll let the shell complain. 1592 */ 1593 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1594 return 0; 1595 1596 shell = get_shell(); 1597 1598 if ((pid = fork()) == 0) { 1599 sigemptyset(&sa.sa_mask); 1600 sa.sa_flags = 0; 1601 sa.sa_handler = SIG_IGN; 1602 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1603 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1604 1605 setctty(_PATH_CONSOLE); 1606 1607 char _sh[] = "sh"; 1608 char _reboot[] = "reboot"; 1609 char _single[] = "single"; 1610 char _path_rundown[] = _PATH_RUNDOWN; 1611 1612 argv[0] = _sh; 1613 argv[1] = _path_rundown; 1614 argv[2] = Reboot ? _reboot : _single; 1615 argv[3] = 0; 1616 1617 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1618 1619 #ifdef LOGIN_CAP 1620 setprocresources(RESOURCE_RC); 1621 #endif 1622 execv(shell, argv); 1623 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1624 _exit(1); /* force single user mode */ 1625 } 1626 1627 if (pid == -1) { 1628 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1629 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1630 continue; 1631 sleep(STALL_TIMEOUT); 1632 return -1; 1633 } 1634 1635 len = sizeof(shutdowntimeout); 1636 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1637 NULL, 0) == -1 || shutdowntimeout < 2) 1638 shutdowntimeout = DEATH_SCRIPT; 1639 alarm(shutdowntimeout); 1640 clang = 0; 1641 /* 1642 * Copied from single_user(). This is a bit paranoid. 1643 * Use the same ALRM handler. 1644 */ 1645 do { 1646 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1647 collect_child(wpid); 1648 if (clang == 1) { 1649 /* we were waiting for the sub-shell */ 1650 kill(wpid, SIGTERM); 1651 warning("timeout expired for %s on %s: %m; going to " 1652 "single user mode", shell, _PATH_RUNDOWN); 1653 return -1; 1654 } 1655 if (wpid == -1) { 1656 if (errno == EINTR) 1657 continue; 1658 warning("wait for %s on %s failed: %m; going to " 1659 "single user mode", shell, _PATH_RUNDOWN); 1660 return -1; 1661 } 1662 if (wpid == pid && WIFSTOPPED(status)) { 1663 warning("init: %s on %s stopped, restarting\n", 1664 shell, _PATH_RUNDOWN); 1665 kill(pid, SIGCONT); 1666 wpid = -1; 1667 } 1668 } while (wpid != pid && !clang); 1669 1670 /* Turn off the alarm */ 1671 alarm(0); 1672 1673 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1674 requested_transition == catatonia) { 1675 /* 1676 * /etc/rc.shutdown executed /sbin/reboot; 1677 * wait for the end quietly 1678 */ 1679 sigset_t s; 1680 1681 sigfillset(&s); 1682 for (;;) 1683 sigsuspend(&s); 1684 } 1685 1686 if (!WIFEXITED(status)) { 1687 warning("%s on %s terminated abnormally, going to " 1688 "single user mode", shell, _PATH_RUNDOWN); 1689 return -2; 1690 } 1691 1692 if ((status = WEXITSTATUS(status)) != 0) 1693 warning("%s returned status %d", _PATH_RUNDOWN, status); 1694 1695 return status; 1696 } 1697 1698 static char * 1699 strk(char *p) 1700 { 1701 static char *t; 1702 char *q; 1703 int c; 1704 1705 if (p) 1706 t = p; 1707 if (!t) 1708 return 0; 1709 1710 c = *t; 1711 while (c == ' ' || c == '\t' ) 1712 c = *++t; 1713 if (!c) { 1714 t = 0; 1715 return 0; 1716 } 1717 q = t; 1718 if (c == '\'') { 1719 c = *++t; 1720 q = t; 1721 while (c && c != '\'') 1722 c = *++t; 1723 if (!c) /* unterminated string */ 1724 q = t = 0; 1725 else 1726 *t++ = 0; 1727 } else { 1728 while (c && c != ' ' && c != '\t' ) 1729 c = *++t; 1730 *t++ = 0; 1731 if (!c) 1732 t = 0; 1733 } 1734 return q; 1735 } 1736 1737 #ifdef LOGIN_CAP 1738 static void 1739 setprocresources(const char *cname) 1740 { 1741 login_cap_t *lc; 1742 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 1743 setusercontext(lc, (struct passwd*)NULL, 0, 1744 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES); 1745 login_close(lc); 1746 } 1747 } 1748 #endif 1749