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 <sys/reboot.h> 70 #include <err.h> 71 72 #include <stdarg.h> 73 74 #ifdef SECURE 75 #include <pwd.h> 76 #endif 77 78 #ifdef LOGIN_CAP 79 #include <login_cap.h> 80 #endif 81 82 #include "pathnames.h" 83 84 /* 85 * Sleep times; used to prevent thrashing. 86 */ 87 #define GETTY_SPACING 5 /* N secs minimum getty spacing */ 88 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 89 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ 90 #define WINDOW_WAIT 3 /* wait N secs after starting window */ 91 #define STALL_TIMEOUT 30 /* wait N secs after warning */ 92 #define DEATH_WATCH 10 /* wait N secs for procs to die */ 93 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */ 94 #define RESOURCE_RC "daemon" 95 #define RESOURCE_WINDOW "default" 96 #define RESOURCE_GETTY "default" 97 98 static void handle(sig_t, ...); 99 static void delset(sigset_t *, ...); 100 101 static void stall(const char *, ...) __printflike(1, 2); 102 static void warning(const char *, ...) __printflike(1, 2); 103 static void emergency(const char *, ...) __printflike(1, 2); 104 static void disaster(int); 105 static void badsys(int); 106 static int runshutdown(void); 107 static char *strk(char *); 108 109 /* 110 * We really need a recursive typedef... 111 * The following at least guarantees that the return type of (*state_t)() 112 * is sufficiently wide to hold a function pointer. 113 */ 114 typedef long (*state_func_t)(void); 115 typedef state_func_t (*state_t)(void); 116 117 static state_func_t single_user(void); 118 static state_func_t runcom(void); 119 static state_func_t read_ttys(void); 120 static state_func_t multi_user(void); 121 static state_func_t clean_ttys(void); 122 static state_func_t catatonia(void); 123 static state_func_t death(void); 124 static state_func_t death_single(void); 125 126 static state_func_t run_script(const char *); 127 128 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 129 #define FALSE 0 130 #define TRUE 1 131 132 static int Reboot = FALSE; 133 static int howto = RB_AUTOBOOT; 134 135 static int devfs; 136 137 static void transition(state_t); 138 static state_t requested_transition; 139 static state_t current_state = death_single; 140 141 static void open_console(void); 142 static const char *get_shell(void); 143 static void write_stderr(const char *message); 144 145 typedef struct init_session { 146 int se_index; /* index of entry in ttys file */ 147 pid_t se_process; /* controlling process */ 148 time_t se_started; /* used to avoid thrashing */ 149 int se_flags; /* status of session */ 150 #define SE_SHUTDOWN 0x1 /* session won't be restarted */ 151 #define SE_PRESENT 0x2 /* session is in /etc/ttys */ 152 int se_nspace; /* spacing count */ 153 char *se_device; /* filename of port */ 154 char *se_getty; /* what to run on that port */ 155 char *se_getty_argv_space; /* pre-parsed argument array space */ 156 char **se_getty_argv; /* pre-parsed argument array */ 157 char *se_window; /* window system (started only once) */ 158 char *se_window_argv_space; /* pre-parsed argument array space */ 159 char **se_window_argv; /* pre-parsed argument array */ 160 char *se_type; /* default terminal type */ 161 struct init_session *se_prev; 162 struct init_session *se_next; 163 } session_t; 164 165 static void free_session(session_t *); 166 static session_t *new_session(session_t *, int, struct ttyent *); 167 static session_t *sessions; 168 169 static char **construct_argv(char *); 170 static void start_window_system(session_t *); 171 static void collect_child(pid_t); 172 static pid_t start_getty(session_t *); 173 static void transition_handler(int); 174 static void alrm_handler(int); 175 static void setsecuritylevel(int); 176 static int getsecuritylevel(void); 177 static int setupargv(session_t *, struct ttyent *); 178 #ifdef LOGIN_CAP 179 static void setprocresources(const char *); 180 #endif 181 static int clang; 182 183 static int start_session_db(void); 184 static void add_session(session_t *); 185 static void del_session(session_t *); 186 static session_t *find_session(pid_t); 187 static DB *session_db; 188 189 /* 190 * The mother of all processes. 191 */ 192 int 193 main(int argc, char *argv[]) 194 { 195 state_t initial_transition = runcom; 196 char kenv_value[PATH_MAX]; 197 int c; 198 struct sigaction sa; 199 sigset_t mask; 200 201 /* Dispose of random users. */ 202 if (getuid() != 0) 203 errx(1, "%s", strerror(EPERM)); 204 205 /* System V users like to reexec init. */ 206 if (getpid() != 1) { 207 #ifdef COMPAT_SYSV_INIT 208 /* So give them what they want */ 209 if (argc > 1) { 210 if (strlen(argv[1]) == 1) { 211 char runlevel = *argv[1]; 212 int sig; 213 214 switch (runlevel) { 215 case '0': /* halt + poweroff */ 216 sig = SIGUSR2; 217 break; 218 case '1': /* single-user */ 219 sig = SIGTERM; 220 break; 221 case '6': /* reboot */ 222 sig = SIGINT; 223 break; 224 case 'c': /* block further logins */ 225 sig = SIGTSTP; 226 break; 227 case 'q': /* rescan /etc/ttys */ 228 sig = SIGHUP; 229 break; 230 default: 231 goto invalid; 232 } 233 kill(1, sig); 234 _exit(0); 235 } else 236 invalid: 237 errx(1, "invalid run-level ``%s''", argv[1]); 238 } else 239 #endif 240 errx(1, "already running"); 241 } 242 /* 243 * Note that this does NOT open a file... 244 * Does 'init' deserve its own facility number? 245 */ 246 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH); 247 248 /* 249 * Create an initial session. 250 */ 251 if (setsid() < 0) 252 warning("initial setsid() failed: %m"); 253 254 /* 255 * Establish an initial user so that programs running 256 * single user do not freak out and die (like passwd). 257 */ 258 if (setlogin("root") < 0) 259 warning("setlogin() failed: %m"); 260 261 /* 262 * This code assumes that we always get arguments through flags, 263 * never through bits set in some random machine register. 264 */ 265 while ((c = getopt(argc, argv, "dsf")) != -1) 266 switch (c) { 267 case 'd': 268 devfs = 1; 269 break; 270 case 's': 271 initial_transition = single_user; 272 break; 273 case 'f': 274 runcom_mode = FASTBOOT; 275 break; 276 default: 277 warning("unrecognized flag '-%c'", c); 278 break; 279 } 280 281 if (optind != argc) 282 warning("ignoring excess arguments"); 283 284 /* 285 * We catch or block signals rather than ignore them, 286 * so that they get reset on exec. 287 */ 288 handle(badsys, SIGSYS, 0); 289 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 290 SIGXFSZ, 0); 291 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGUSR1, 292 SIGUSR2, 0); 293 handle(alrm_handler, SIGALRM, 0); 294 sigfillset(&mask); 295 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 296 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM, 297 SIGUSR1, SIGUSR2, 0); 298 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 299 sigemptyset(&sa.sa_mask); 300 sa.sa_flags = 0; 301 sa.sa_handler = SIG_IGN; 302 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 303 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 304 305 /* 306 * Paranoia. 307 */ 308 close(0); 309 close(1); 310 close(2); 311 312 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 313 state_func_t next_transition; 314 315 if ((next_transition = run_script(kenv_value)) != 0) 316 initial_transition = (state_t) next_transition; 317 } 318 319 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 320 if (chdir(kenv_value) != 0 || chroot(".") != 0) 321 warning("Can't chroot to %s: %m", kenv_value); 322 } 323 324 /* 325 * Additional check if devfs needs to be mounted: 326 * If "/" and "/dev" have the same device number, 327 * then it hasn't been mounted yet. 328 */ 329 if (!devfs) { 330 struct stat stst; 331 dev_t root_devno; 332 333 stat("/", &stst); 334 root_devno = stst.st_dev; 335 if (stat("/dev", &stst) != 0) 336 warning("Can't stat /dev: %m"); 337 else if (stst.st_dev == root_devno) 338 devfs++; 339 } 340 341 if (devfs) { 342 struct iovec iov[4]; 343 char *s; 344 int i; 345 346 char _fstype[] = "fstype"; 347 char _devfs[] = "devfs"; 348 char _fspath[] = "fspath"; 349 char _path_dev[]= _PATH_DEV; 350 351 iov[0].iov_base = _fstype; 352 iov[0].iov_len = sizeof(_fstype); 353 iov[1].iov_base = _devfs; 354 iov[1].iov_len = sizeof(_devfs); 355 iov[2].iov_base = _fspath; 356 iov[2].iov_len = sizeof(_fspath); 357 /* 358 * Try to avoid the trailing slash in _PATH_DEV. 359 * Be *very* defensive. 360 */ 361 s = strdup(_PATH_DEV); 362 if (s != NULL) { 363 i = strlen(s); 364 if (i > 0 && s[i - 1] == '/') 365 s[i - 1] = '\0'; 366 iov[3].iov_base = s; 367 iov[3].iov_len = strlen(s) + 1; 368 } else { 369 iov[3].iov_base = _path_dev; 370 iov[3].iov_len = sizeof(_path_dev); 371 } 372 nmount(iov, 4, 0); 373 if (s != NULL) 374 free(s); 375 } 376 377 /* 378 * Start the state machine. 379 */ 380 transition(initial_transition); 381 382 /* 383 * Should never reach here. 384 */ 385 return 1; 386 } 387 388 /* 389 * Associate a function with a signal handler. 390 */ 391 static void 392 handle(sig_t handler, ...) 393 { 394 int sig; 395 struct sigaction sa; 396 sigset_t mask_everything; 397 va_list ap; 398 va_start(ap, handler); 399 400 sa.sa_handler = handler; 401 sigfillset(&mask_everything); 402 403 while ((sig = va_arg(ap, int)) != 0) { 404 sa.sa_mask = mask_everything; 405 /* XXX SA_RESTART? */ 406 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 407 sigaction(sig, &sa, (struct sigaction *) 0); 408 } 409 va_end(ap); 410 } 411 412 /* 413 * Delete a set of signals from a mask. 414 */ 415 static void 416 delset(sigset_t *maskp, ...) 417 { 418 int sig; 419 va_list ap; 420 va_start(ap, maskp); 421 422 while ((sig = va_arg(ap, int)) != 0) 423 sigdelset(maskp, sig); 424 va_end(ap); 425 } 426 427 /* 428 * Log a message and sleep for a while (to give someone an opportunity 429 * to read it and to save log or hardcopy output if the problem is chronic). 430 * NB: should send a message to the session logger to avoid blocking. 431 */ 432 static void 433 stall(const char *message, ...) 434 { 435 va_list ap; 436 va_start(ap, message); 437 438 vsyslog(LOG_ALERT, message, ap); 439 va_end(ap); 440 sleep(STALL_TIMEOUT); 441 } 442 443 /* 444 * Like stall(), but doesn't sleep. 445 * If cpp had variadic macros, the two functions could be #defines for another. 446 * NB: should send a message to the session logger to avoid blocking. 447 */ 448 static void 449 warning(const char *message, ...) 450 { 451 va_list ap; 452 va_start(ap, message); 453 454 vsyslog(LOG_ALERT, message, ap); 455 va_end(ap); 456 } 457 458 /* 459 * Log an emergency message. 460 * NB: should send a message to the session logger to avoid blocking. 461 */ 462 static void 463 emergency(const char *message, ...) 464 { 465 va_list ap; 466 va_start(ap, message); 467 468 vsyslog(LOG_EMERG, message, ap); 469 va_end(ap); 470 } 471 472 /* 473 * Catch a SIGSYS signal. 474 * 475 * These may arise if a system does not support sysctl. 476 * We tolerate up to 25 of these, then throw in the towel. 477 */ 478 static void 479 badsys(int sig) 480 { 481 static int badcount = 0; 482 483 if (badcount++ < 25) 484 return; 485 disaster(sig); 486 } 487 488 /* 489 * Catch an unexpected signal. 490 */ 491 static void 492 disaster(int sig) 493 { 494 495 emergency("fatal signal: %s", 496 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 497 498 sleep(STALL_TIMEOUT); 499 _exit(sig); /* reboot */ 500 } 501 502 /* 503 * Get the security level of the kernel. 504 */ 505 static int 506 getsecuritylevel(void) 507 { 508 #ifdef KERN_SECURELVL 509 int name[2], curlevel; 510 size_t len; 511 512 name[0] = CTL_KERN; 513 name[1] = KERN_SECURELVL; 514 len = sizeof curlevel; 515 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 516 emergency("cannot get kernel security level: %s", 517 strerror(errno)); 518 return (-1); 519 } 520 return (curlevel); 521 #else 522 return (-1); 523 #endif 524 } 525 526 /* 527 * Set the security level of the kernel. 528 */ 529 static void 530 setsecuritylevel(int newlevel) 531 { 532 #ifdef KERN_SECURELVL 533 int name[2], curlevel; 534 535 curlevel = getsecuritylevel(); 536 if (newlevel == curlevel) 537 return; 538 name[0] = CTL_KERN; 539 name[1] = KERN_SECURELVL; 540 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 541 emergency( 542 "cannot change kernel security level from %d to %d: %s", 543 curlevel, newlevel, strerror(errno)); 544 return; 545 } 546 #ifdef SECURE 547 warning("kernel security level changed from %d to %d", 548 curlevel, newlevel); 549 #endif 550 #endif 551 } 552 553 /* 554 * Change states in the finite state machine. 555 * The initial state is passed as an argument. 556 */ 557 static void 558 transition(state_t s) 559 { 560 561 current_state = s; 562 for (;;) 563 current_state = (state_t) (*current_state)(); 564 } 565 566 /* 567 * Start a session and allocate a controlling terminal. 568 * Only called by children of init after forking. 569 */ 570 static void 571 open_console(void) 572 { 573 int fd; 574 575 /* 576 * Try to open /dev/console. Open the device with O_NONBLOCK to 577 * prevent potential blocking on a carrier. 578 */ 579 revoke(_PATH_CONSOLE); 580 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 581 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 582 if (login_tty(fd) == 0) 583 return; 584 close(fd); 585 } 586 587 /* No luck. Log output to file if possible. */ 588 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 589 stall("cannot open null device."); 590 _exit(1); 591 } 592 if (fd != STDIN_FILENO) { 593 dup2(fd, STDIN_FILENO); 594 close(fd); 595 } 596 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 597 if (fd == -1) 598 dup2(STDIN_FILENO, STDOUT_FILENO); 599 else if (fd != STDOUT_FILENO) { 600 dup2(fd, STDOUT_FILENO); 601 close(fd); 602 } 603 dup2(STDOUT_FILENO, STDERR_FILENO); 604 } 605 606 static const char * 607 get_shell(void) 608 { 609 static char kenv_value[PATH_MAX]; 610 611 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 612 return kenv_value; 613 else 614 return _PATH_BSHELL; 615 } 616 617 static void 618 write_stderr(const char *message) 619 { 620 621 write(STDERR_FILENO, message, strlen(message)); 622 } 623 624 /* 625 * Bring the system up single user. 626 */ 627 static state_func_t 628 single_user(void) 629 { 630 pid_t pid, wpid; 631 int status; 632 sigset_t mask; 633 const char *shell; 634 char *argv[2]; 635 #ifdef SECURE 636 struct ttyent *typ; 637 struct passwd *pp; 638 static const char banner[] = 639 "Enter root password, or ^D to go multi-user\n"; 640 char *clear, *password; 641 #endif 642 #ifdef DEBUGSHELL 643 char altshell[128]; 644 #endif 645 646 if (Reboot) { 647 /* Instead of going single user, let's reboot the machine */ 648 sync(); 649 reboot(howto); 650 _exit(0); 651 } 652 653 shell = get_shell(); 654 655 if ((pid = fork()) == 0) { 656 /* 657 * Start the single user session. 658 */ 659 open_console(); 660 661 #ifdef SECURE 662 /* 663 * Check the root password. 664 * We don't care if the console is 'on' by default; 665 * it's the only tty that can be 'off' and 'secure'. 666 */ 667 typ = getttynam("console"); 668 pp = getpwnam("root"); 669 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 670 pp && *pp->pw_passwd) { 671 write_stderr(banner); 672 for (;;) { 673 clear = getpass("Password:"); 674 if (clear == 0 || *clear == '\0') 675 _exit(0); 676 password = crypt(clear, pp->pw_passwd); 677 bzero(clear, _PASSWORD_LEN); 678 if (password == NULL || 679 strcmp(password, pp->pw_passwd) == 0) 680 break; 681 warning("single-user login failed\n"); 682 } 683 } 684 endttyent(); 685 endpwent(); 686 #endif /* SECURE */ 687 688 #ifdef DEBUGSHELL 689 { 690 char *cp = altshell; 691 int num; 692 693 #define SHREQUEST "Enter full pathname of shell or RETURN for " 694 write_stderr(SHREQUEST); 695 write_stderr(shell); 696 write_stderr(": "); 697 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 698 num != 0 && *cp != '\n' && cp < &altshell[127]) 699 cp++; 700 *cp = '\0'; 701 if (altshell[0] != '\0') 702 shell = altshell; 703 } 704 #endif /* DEBUGSHELL */ 705 706 /* 707 * Unblock signals. 708 * We catch all the interesting ones, 709 * and those are reset to SIG_DFL on exec. 710 */ 711 sigemptyset(&mask); 712 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 713 714 /* 715 * Fire off a shell. 716 * If the default one doesn't work, try the Bourne shell. 717 */ 718 719 char name[] = "-sh"; 720 721 argv[0] = name; 722 argv[1] = 0; 723 execv(shell, argv); 724 emergency("can't exec %s for single user: %m", shell); 725 execv(_PATH_BSHELL, argv); 726 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 727 sleep(STALL_TIMEOUT); 728 _exit(1); 729 } 730 731 if (pid == -1) { 732 /* 733 * We are seriously hosed. Do our best. 734 */ 735 emergency("can't fork single-user shell, trying again"); 736 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 737 continue; 738 return (state_func_t) single_user; 739 } 740 741 requested_transition = 0; 742 do { 743 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 744 collect_child(wpid); 745 if (wpid == -1) { 746 if (errno == EINTR) 747 continue; 748 warning("wait for single-user shell failed: %m; restarting"); 749 return (state_func_t) single_user; 750 } 751 if (wpid == pid && WIFSTOPPED(status)) { 752 warning("init: shell stopped, restarting\n"); 753 kill(pid, SIGCONT); 754 wpid = -1; 755 } 756 } while (wpid != pid && !requested_transition); 757 758 if (requested_transition) 759 return (state_func_t) requested_transition; 760 761 if (!WIFEXITED(status)) { 762 if (WTERMSIG(status) == SIGKILL) { 763 /* 764 * reboot(8) killed shell? 765 */ 766 warning("single user shell terminated."); 767 sleep(STALL_TIMEOUT); 768 _exit(0); 769 } else { 770 warning("single user shell terminated, restarting"); 771 return (state_func_t) single_user; 772 } 773 } 774 775 runcom_mode = FASTBOOT; 776 return (state_func_t) runcom; 777 } 778 779 /* 780 * Run the system startup script. 781 */ 782 static state_func_t 783 runcom(void) 784 { 785 state_func_t next_transition; 786 787 if ((next_transition = run_script(_PATH_RUNCOM)) != 0) 788 return next_transition; 789 790 runcom_mode = AUTOBOOT; /* the default */ 791 return (state_func_t) read_ttys; 792 } 793 794 /* 795 * Run a shell script. 796 * Returns 0 on success, otherwise the next transition to enter: 797 * - single_user if fork/execv/waitpid failed, or if the script 798 * terminated with a signal or exit code != 0. 799 * - death_single if a SIGTERM was delivered to init(8). 800 */ 801 static state_func_t 802 run_script(const char *script) 803 { 804 pid_t pid, wpid; 805 int status; 806 char *argv[4]; 807 const char *shell; 808 struct sigaction sa; 809 810 shell = get_shell(); 811 812 if ((pid = fork()) == 0) { 813 sigemptyset(&sa.sa_mask); 814 sa.sa_flags = 0; 815 sa.sa_handler = SIG_IGN; 816 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 817 sigaction(SIGHUP, &sa, (struct sigaction *)0); 818 819 open_console(); 820 821 char _sh[] = "sh"; 822 char _autoboot[] = "autoboot"; 823 824 argv[0] = _sh; 825 argv[1] = __DECONST(char *, script); 826 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 827 argv[3] = 0; 828 829 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 830 831 #ifdef LOGIN_CAP 832 setprocresources(RESOURCE_RC); 833 #endif 834 execv(shell, argv); 835 stall("can't exec %s for %s: %m", shell, script); 836 _exit(1); /* force single user mode */ 837 } 838 839 if (pid == -1) { 840 emergency("can't fork for %s on %s: %m", shell, script); 841 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 842 continue; 843 sleep(STALL_TIMEOUT); 844 return (state_func_t) single_user; 845 } 846 847 /* 848 * Copied from single_user(). This is a bit paranoid. 849 */ 850 requested_transition = 0; 851 do { 852 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 853 collect_child(wpid); 854 if (wpid == -1) { 855 if (requested_transition == death_single) 856 return (state_func_t) death_single; 857 if (errno == EINTR) 858 continue; 859 warning("wait for %s on %s failed: %m; going to " 860 "single user mode", shell, script); 861 return (state_func_t) single_user; 862 } 863 if (wpid == pid && WIFSTOPPED(status)) { 864 warning("init: %s on %s stopped, restarting\n", 865 shell, script); 866 kill(pid, SIGCONT); 867 wpid = -1; 868 } 869 } while (wpid != pid); 870 871 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 872 requested_transition == catatonia) { 873 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 874 sigset_t s; 875 876 sigfillset(&s); 877 for (;;) 878 sigsuspend(&s); 879 } 880 881 if (!WIFEXITED(status)) { 882 warning("%s on %s terminated abnormally, going to single " 883 "user mode", shell, script); 884 return (state_func_t) single_user; 885 } 886 887 if (WEXITSTATUS(status)) 888 return (state_func_t) single_user; 889 890 return (state_func_t) 0; 891 } 892 893 /* 894 * Open the session database. 895 * 896 * NB: We could pass in the size here; is it necessary? 897 */ 898 static int 899 start_session_db(void) 900 { 901 if (session_db && (*session_db->close)(session_db)) 902 emergency("session database close: %s", strerror(errno)); 903 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 904 emergency("session database open: %s", strerror(errno)); 905 return (1); 906 } 907 return (0); 908 909 } 910 911 /* 912 * Add a new login session. 913 */ 914 static void 915 add_session(session_t *sp) 916 { 917 DBT key; 918 DBT data; 919 920 key.data = &sp->se_process; 921 key.size = sizeof sp->se_process; 922 data.data = &sp; 923 data.size = sizeof sp; 924 925 if ((*session_db->put)(session_db, &key, &data, 0)) 926 emergency("insert %d: %s", sp->se_process, strerror(errno)); 927 } 928 929 /* 930 * Delete an old login session. 931 */ 932 static void 933 del_session(session_t *sp) 934 { 935 DBT key; 936 937 key.data = &sp->se_process; 938 key.size = sizeof sp->se_process; 939 940 if ((*session_db->del)(session_db, &key, 0)) 941 emergency("delete %d: %s", sp->se_process, strerror(errno)); 942 } 943 944 /* 945 * Look up a login session by pid. 946 */ 947 static session_t * 948 find_session(pid_t pid) 949 { 950 DBT key; 951 DBT data; 952 session_t *ret; 953 954 key.data = &pid; 955 key.size = sizeof pid; 956 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 957 return 0; 958 bcopy(data.data, (char *)&ret, sizeof(ret)); 959 return ret; 960 } 961 962 /* 963 * Construct an argument vector from a command line. 964 */ 965 static char ** 966 construct_argv(char *command) 967 { 968 int argc = 0; 969 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 970 * sizeof (char *)); 971 972 if ((argv[argc++] = strk(command)) == 0) { 973 free(argv); 974 return (NULL); 975 } 976 while ((argv[argc++] = strk((char *) 0)) != NULL) 977 continue; 978 return argv; 979 } 980 981 /* 982 * Deallocate a session descriptor. 983 */ 984 static void 985 free_session(session_t *sp) 986 { 987 free(sp->se_device); 988 if (sp->se_getty) { 989 free(sp->se_getty); 990 free(sp->se_getty_argv_space); 991 free(sp->se_getty_argv); 992 } 993 if (sp->se_window) { 994 free(sp->se_window); 995 free(sp->se_window_argv_space); 996 free(sp->se_window_argv); 997 } 998 if (sp->se_type) 999 free(sp->se_type); 1000 free(sp); 1001 } 1002 1003 /* 1004 * Allocate a new session descriptor. 1005 * Mark it SE_PRESENT. 1006 */ 1007 static session_t * 1008 new_session(session_t *sprev, int session_index, struct ttyent *typ) 1009 { 1010 session_t *sp; 1011 int fd; 1012 1013 if ((typ->ty_status & TTY_ON) == 0 || 1014 typ->ty_name == 0 || 1015 typ->ty_getty == 0) 1016 return 0; 1017 1018 sp = (session_t *) calloc(1, sizeof (session_t)); 1019 1020 sp->se_index = session_index; 1021 sp->se_flags |= SE_PRESENT; 1022 1023 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 1024 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 1025 1026 /* 1027 * Attempt to open the device, if we get "device not configured" 1028 * then don't add the device to the session list. 1029 */ 1030 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) { 1031 if (errno == ENXIO) { 1032 free_session(sp); 1033 return (0); 1034 } 1035 } else 1036 close(fd); 1037 1038 if (setupargv(sp, typ) == 0) { 1039 free_session(sp); 1040 return (0); 1041 } 1042 1043 sp->se_next = 0; 1044 if (sprev == 0) { 1045 sessions = sp; 1046 sp->se_prev = 0; 1047 } else { 1048 sprev->se_next = sp; 1049 sp->se_prev = sprev; 1050 } 1051 1052 return sp; 1053 } 1054 1055 /* 1056 * Calculate getty and if useful window argv vectors. 1057 */ 1058 static int 1059 setupargv(session_t *sp, struct ttyent *typ) 1060 { 1061 1062 if (sp->se_getty) { 1063 free(sp->se_getty); 1064 free(sp->se_getty_argv_space); 1065 free(sp->se_getty_argv); 1066 } 1067 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 1068 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 1069 sp->se_getty_argv_space = strdup(sp->se_getty); 1070 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1071 if (sp->se_getty_argv == 0) { 1072 warning("can't parse getty for port %s", sp->se_device); 1073 free(sp->se_getty); 1074 free(sp->se_getty_argv_space); 1075 sp->se_getty = sp->se_getty_argv_space = 0; 1076 return (0); 1077 } 1078 if (sp->se_window) { 1079 free(sp->se_window); 1080 free(sp->se_window_argv_space); 1081 free(sp->se_window_argv); 1082 } 1083 sp->se_window = sp->se_window_argv_space = 0; 1084 sp->se_window_argv = 0; 1085 if (typ->ty_window) { 1086 sp->se_window = strdup(typ->ty_window); 1087 sp->se_window_argv_space = strdup(sp->se_window); 1088 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1089 if (sp->se_window_argv == 0) { 1090 warning("can't parse window for port %s", 1091 sp->se_device); 1092 free(sp->se_window_argv_space); 1093 free(sp->se_window); 1094 sp->se_window = sp->se_window_argv_space = 0; 1095 return (0); 1096 } 1097 } 1098 if (sp->se_type) 1099 free(sp->se_type); 1100 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1101 return (1); 1102 } 1103 1104 /* 1105 * Walk the list of ttys and create sessions for each active line. 1106 */ 1107 static state_func_t 1108 read_ttys(void) 1109 { 1110 int session_index = 0; 1111 session_t *sp, *snext; 1112 struct ttyent *typ; 1113 1114 /* 1115 * Destroy any previous session state. 1116 * There shouldn't be any, but just in case... 1117 */ 1118 for (sp = sessions; sp; sp = snext) { 1119 snext = sp->se_next; 1120 free_session(sp); 1121 } 1122 sessions = 0; 1123 if (start_session_db()) 1124 return (state_func_t) single_user; 1125 1126 /* 1127 * Allocate a session entry for each active port. 1128 * Note that sp starts at 0. 1129 */ 1130 while ((typ = getttyent()) != NULL) 1131 if ((snext = new_session(sp, ++session_index, typ)) != NULL) 1132 sp = snext; 1133 1134 endttyent(); 1135 1136 return (state_func_t) multi_user; 1137 } 1138 1139 /* 1140 * Start a window system running. 1141 */ 1142 static void 1143 start_window_system(session_t *sp) 1144 { 1145 pid_t pid; 1146 sigset_t mask; 1147 char term[64], *env[2]; 1148 int status; 1149 1150 if ((pid = fork()) == -1) { 1151 emergency("can't fork for window system on port %s: %m", 1152 sp->se_device); 1153 /* hope that getty fails and we can try again */ 1154 return; 1155 } 1156 if (pid) { 1157 waitpid(-1, &status, 0); 1158 return; 1159 } 1160 1161 /* reparent window process to the init to not make a zombie on exit */ 1162 if ((pid = fork()) == -1) { 1163 emergency("can't fork for window system on port %s: %m", 1164 sp->se_device); 1165 _exit(1); 1166 } 1167 if (pid) 1168 _exit(0); 1169 1170 sigemptyset(&mask); 1171 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1172 1173 if (setsid() < 0) 1174 emergency("setsid failed (window) %m"); 1175 1176 #ifdef LOGIN_CAP 1177 setprocresources(RESOURCE_WINDOW); 1178 #endif 1179 if (sp->se_type) { 1180 /* Don't use malloc after fork */ 1181 strcpy(term, "TERM="); 1182 strncat(term, sp->se_type, sizeof(term) - 6); 1183 env[0] = term; 1184 env[1] = 0; 1185 } 1186 else 1187 env[0] = 0; 1188 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1189 stall("can't exec window system '%s' for port %s: %m", 1190 sp->se_window_argv[0], sp->se_device); 1191 _exit(1); 1192 } 1193 1194 /* 1195 * Start a login session running. 1196 */ 1197 static pid_t 1198 start_getty(session_t *sp) 1199 { 1200 pid_t pid; 1201 sigset_t mask; 1202 time_t current_time = time((time_t *) 0); 1203 int too_quick = 0; 1204 char term[64], *env[2]; 1205 1206 if (current_time >= sp->se_started && 1207 current_time - sp->se_started < GETTY_SPACING) { 1208 if (++sp->se_nspace > GETTY_NSPACE) { 1209 sp->se_nspace = 0; 1210 too_quick = 1; 1211 } 1212 } else 1213 sp->se_nspace = 0; 1214 1215 /* 1216 * fork(), not vfork() -- we can't afford to block. 1217 */ 1218 if ((pid = fork()) == -1) { 1219 emergency("can't fork for getty on port %s: %m", sp->se_device); 1220 return -1; 1221 } 1222 1223 if (pid) 1224 return pid; 1225 1226 if (too_quick) { 1227 warning("getty repeating too quickly on port %s, sleeping %d secs", 1228 sp->se_device, GETTY_SLEEP); 1229 sleep((unsigned) GETTY_SLEEP); 1230 } 1231 1232 if (sp->se_window) { 1233 start_window_system(sp); 1234 sleep(WINDOW_WAIT); 1235 } 1236 1237 sigemptyset(&mask); 1238 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1239 1240 #ifdef LOGIN_CAP 1241 setprocresources(RESOURCE_GETTY); 1242 #endif 1243 if (sp->se_type) { 1244 /* Don't use malloc after fork */ 1245 strcpy(term, "TERM="); 1246 strncat(term, sp->se_type, sizeof(term) - 6); 1247 env[0] = term; 1248 env[1] = 0; 1249 } else 1250 env[0] = 0; 1251 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1252 stall("can't exec getty '%s' for port %s: %m", 1253 sp->se_getty_argv[0], sp->se_device); 1254 _exit(1); 1255 } 1256 1257 /* 1258 * Collect exit status for a child. 1259 * If an exiting login, start a new login running. 1260 */ 1261 static void 1262 collect_child(pid_t pid) 1263 { 1264 session_t *sp, *sprev, *snext; 1265 1266 if (! sessions) 1267 return; 1268 1269 if (! (sp = find_session(pid))) 1270 return; 1271 1272 del_session(sp); 1273 sp->se_process = 0; 1274 1275 if (sp->se_flags & SE_SHUTDOWN) { 1276 if ((sprev = sp->se_prev) != NULL) 1277 sprev->se_next = sp->se_next; 1278 else 1279 sessions = sp->se_next; 1280 if ((snext = sp->se_next) != NULL) 1281 snext->se_prev = sp->se_prev; 1282 free_session(sp); 1283 return; 1284 } 1285 1286 if ((pid = start_getty(sp)) == -1) { 1287 /* serious trouble */ 1288 requested_transition = clean_ttys; 1289 return; 1290 } 1291 1292 sp->se_process = pid; 1293 sp->se_started = time((time_t *) 0); 1294 add_session(sp); 1295 } 1296 1297 /* 1298 * Catch a signal and request a state transition. 1299 */ 1300 static void 1301 transition_handler(int sig) 1302 { 1303 1304 switch (sig) { 1305 case SIGHUP: 1306 if (current_state == read_ttys || current_state == multi_user || 1307 current_state == clean_ttys || current_state == catatonia) 1308 requested_transition = clean_ttys; 1309 break; 1310 case SIGUSR2: 1311 howto = RB_POWEROFF; 1312 case SIGUSR1: 1313 howto |= RB_HALT; 1314 case SIGINT: 1315 Reboot = TRUE; 1316 case SIGTERM: 1317 if (current_state == read_ttys || current_state == multi_user || 1318 current_state == clean_ttys || current_state == catatonia) 1319 requested_transition = death; 1320 else 1321 requested_transition = death_single; 1322 break; 1323 case SIGTSTP: 1324 if (current_state == runcom || current_state == read_ttys || 1325 current_state == clean_ttys || 1326 current_state == multi_user || current_state == catatonia) 1327 requested_transition = catatonia; 1328 break; 1329 default: 1330 requested_transition = 0; 1331 break; 1332 } 1333 } 1334 1335 /* 1336 * Take the system multiuser. 1337 */ 1338 static state_func_t 1339 multi_user(void) 1340 { 1341 pid_t pid; 1342 session_t *sp; 1343 1344 requested_transition = 0; 1345 1346 /* 1347 * If the administrator has not set the security level to -1 1348 * to indicate that the kernel should not run multiuser in secure 1349 * mode, and the run script has not set a higher level of security 1350 * than level 1, then put the kernel into secure mode. 1351 */ 1352 if (getsecuritylevel() == 0) 1353 setsecuritylevel(1); 1354 1355 for (sp = sessions; sp; sp = sp->se_next) { 1356 if (sp->se_process) 1357 continue; 1358 if ((pid = start_getty(sp)) == -1) { 1359 /* serious trouble */ 1360 requested_transition = clean_ttys; 1361 break; 1362 } 1363 sp->se_process = pid; 1364 sp->se_started = time((time_t *) 0); 1365 add_session(sp); 1366 } 1367 1368 while (!requested_transition) 1369 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1370 collect_child(pid); 1371 1372 return (state_func_t) requested_transition; 1373 } 1374 1375 /* 1376 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1377 */ 1378 static state_func_t 1379 clean_ttys(void) 1380 { 1381 session_t *sp, *sprev; 1382 struct ttyent *typ; 1383 int session_index = 0; 1384 int devlen; 1385 char *old_getty, *old_window, *old_type; 1386 1387 /* 1388 * mark all sessions for death, (!SE_PRESENT) 1389 * as we find or create new ones they'll be marked as keepers, 1390 * we'll later nuke all the ones not found in /etc/ttys 1391 */ 1392 for (sp = sessions; sp != NULL; sp = sp->se_next) 1393 sp->se_flags &= ~SE_PRESENT; 1394 1395 devlen = sizeof(_PATH_DEV) - 1; 1396 while ((typ = getttyent()) != NULL) { 1397 ++session_index; 1398 1399 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1400 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1401 break; 1402 1403 if (sp) { 1404 /* we want this one to live */ 1405 sp->se_flags |= SE_PRESENT; 1406 if (sp->se_index != session_index) { 1407 warning("port %s changed utmp index from %d to %d", 1408 sp->se_device, sp->se_index, 1409 session_index); 1410 sp->se_index = session_index; 1411 } 1412 if ((typ->ty_status & TTY_ON) == 0 || 1413 typ->ty_getty == 0) { 1414 sp->se_flags |= SE_SHUTDOWN; 1415 kill(sp->se_process, SIGHUP); 1416 continue; 1417 } 1418 sp->se_flags &= ~SE_SHUTDOWN; 1419 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1420 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1421 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1422 if (setupargv(sp, typ) == 0) { 1423 warning("can't parse getty for port %s", 1424 sp->se_device); 1425 sp->se_flags |= SE_SHUTDOWN; 1426 kill(sp->se_process, SIGHUP); 1427 } 1428 else if ( !old_getty 1429 || (!old_type && sp->se_type) 1430 || (old_type && !sp->se_type) 1431 || (!old_window && sp->se_window) 1432 || (old_window && !sp->se_window) 1433 || (strcmp(old_getty, sp->se_getty) != 0) 1434 || (old_window && strcmp(old_window, sp->se_window) != 0) 1435 || (old_type && strcmp(old_type, sp->se_type) != 0) 1436 ) { 1437 /* Don't set SE_SHUTDOWN here */ 1438 sp->se_nspace = 0; 1439 sp->se_started = 0; 1440 kill(sp->se_process, SIGHUP); 1441 } 1442 if (old_getty) 1443 free(old_getty); 1444 if (old_window) 1445 free(old_window); 1446 if (old_type) 1447 free(old_type); 1448 continue; 1449 } 1450 1451 new_session(sprev, session_index, typ); 1452 } 1453 1454 endttyent(); 1455 1456 /* 1457 * sweep through and kill all deleted sessions 1458 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1459 */ 1460 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1461 if ((sp->se_flags & SE_PRESENT) == 0) { 1462 sp->se_flags |= SE_SHUTDOWN; 1463 kill(sp->se_process, SIGHUP); 1464 } 1465 } 1466 1467 return (state_func_t) multi_user; 1468 } 1469 1470 /* 1471 * Block further logins. 1472 */ 1473 static state_func_t 1474 catatonia(void) 1475 { 1476 session_t *sp; 1477 1478 for (sp = sessions; sp; sp = sp->se_next) 1479 sp->se_flags |= SE_SHUTDOWN; 1480 1481 return (state_func_t) multi_user; 1482 } 1483 1484 /* 1485 * Note SIGALRM. 1486 */ 1487 static void 1488 alrm_handler(int sig) 1489 { 1490 1491 (void)sig; 1492 clang = 1; 1493 } 1494 1495 /* 1496 * Bring the system down to single user. 1497 */ 1498 static state_func_t 1499 death(void) 1500 { 1501 session_t *sp; 1502 1503 /* 1504 * Also revoke the TTY here. Because runshutdown() may reopen 1505 * the TTY whose getty we're killing here, there is no guarantee 1506 * runshutdown() will perform the initial open() call, causing 1507 * the terminal attributes to be misconfigured. 1508 */ 1509 for (sp = sessions; sp; sp = sp->se_next) { 1510 sp->se_flags |= SE_SHUTDOWN; 1511 kill(sp->se_process, SIGHUP); 1512 revoke(sp->se_device); 1513 } 1514 1515 /* Try to run the rc.shutdown script within a period of time */ 1516 runshutdown(); 1517 1518 return (state_func_t) death_single; 1519 } 1520 1521 /* 1522 * Do what is necessary to reinitialize single user mode or reboot 1523 * from an incomplete state. 1524 */ 1525 static state_func_t 1526 death_single(void) 1527 { 1528 int i; 1529 pid_t pid; 1530 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1531 1532 revoke(_PATH_CONSOLE); 1533 1534 for (i = 0; i < 2; ++i) { 1535 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1536 return (state_func_t) single_user; 1537 1538 clang = 0; 1539 alarm(DEATH_WATCH); 1540 do 1541 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1542 collect_child(pid); 1543 while (clang == 0 && errno != ECHILD); 1544 1545 if (errno == ECHILD) 1546 return (state_func_t) single_user; 1547 } 1548 1549 warning("some processes would not die; ps axl advised"); 1550 1551 return (state_func_t) single_user; 1552 } 1553 1554 /* 1555 * Run the system shutdown script. 1556 * 1557 * Exit codes: XXX I should document more 1558 * -2 shutdown script terminated abnormally 1559 * -1 fatal error - can't run script 1560 * 0 good. 1561 * >0 some error (exit code) 1562 */ 1563 static int 1564 runshutdown(void) 1565 { 1566 pid_t pid, wpid; 1567 int status; 1568 int shutdowntimeout; 1569 size_t len; 1570 char *argv[4]; 1571 const char *shell; 1572 struct sigaction sa; 1573 struct stat sb; 1574 1575 /* 1576 * rc.shutdown is optional, so to prevent any unnecessary 1577 * complaints from the shell we simply don't run it if the 1578 * file does not exist. If the stat() here fails for other 1579 * reasons, we'll let the shell complain. 1580 */ 1581 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1582 return 0; 1583 1584 shell = get_shell(); 1585 1586 if ((pid = fork()) == 0) { 1587 sigemptyset(&sa.sa_mask); 1588 sa.sa_flags = 0; 1589 sa.sa_handler = SIG_IGN; 1590 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1591 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1592 1593 open_console(); 1594 1595 char _sh[] = "sh"; 1596 char _reboot[] = "reboot"; 1597 char _single[] = "single"; 1598 char _path_rundown[] = _PATH_RUNDOWN; 1599 1600 argv[0] = _sh; 1601 argv[1] = _path_rundown; 1602 argv[2] = Reboot ? _reboot : _single; 1603 argv[3] = 0; 1604 1605 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1606 1607 #ifdef LOGIN_CAP 1608 setprocresources(RESOURCE_RC); 1609 #endif 1610 execv(shell, argv); 1611 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1612 _exit(1); /* force single user mode */ 1613 } 1614 1615 if (pid == -1) { 1616 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1617 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1618 continue; 1619 sleep(STALL_TIMEOUT); 1620 return -1; 1621 } 1622 1623 len = sizeof(shutdowntimeout); 1624 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1625 NULL, 0) == -1 || shutdowntimeout < 2) 1626 shutdowntimeout = DEATH_SCRIPT; 1627 alarm(shutdowntimeout); 1628 clang = 0; 1629 /* 1630 * Copied from single_user(). This is a bit paranoid. 1631 * Use the same ALRM handler. 1632 */ 1633 do { 1634 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1635 collect_child(wpid); 1636 if (clang == 1) { 1637 /* we were waiting for the sub-shell */ 1638 kill(wpid, SIGTERM); 1639 warning("timeout expired for %s on %s: %m; going to " 1640 "single user mode", shell, _PATH_RUNDOWN); 1641 return -1; 1642 } 1643 if (wpid == -1) { 1644 if (errno == EINTR) 1645 continue; 1646 warning("wait for %s on %s failed: %m; going to " 1647 "single user mode", shell, _PATH_RUNDOWN); 1648 return -1; 1649 } 1650 if (wpid == pid && WIFSTOPPED(status)) { 1651 warning("init: %s on %s stopped, restarting\n", 1652 shell, _PATH_RUNDOWN); 1653 kill(pid, SIGCONT); 1654 wpid = -1; 1655 } 1656 } while (wpid != pid && !clang); 1657 1658 /* Turn off the alarm */ 1659 alarm(0); 1660 1661 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1662 requested_transition == catatonia) { 1663 /* 1664 * /etc/rc.shutdown executed /sbin/reboot; 1665 * wait for the end quietly 1666 */ 1667 sigset_t s; 1668 1669 sigfillset(&s); 1670 for (;;) 1671 sigsuspend(&s); 1672 } 1673 1674 if (!WIFEXITED(status)) { 1675 warning("%s on %s terminated abnormally, going to " 1676 "single user mode", shell, _PATH_RUNDOWN); 1677 return -2; 1678 } 1679 1680 if ((status = WEXITSTATUS(status)) != 0) 1681 warning("%s returned status %d", _PATH_RUNDOWN, status); 1682 1683 return status; 1684 } 1685 1686 static char * 1687 strk(char *p) 1688 { 1689 static char *t; 1690 char *q; 1691 int c; 1692 1693 if (p) 1694 t = p; 1695 if (!t) 1696 return 0; 1697 1698 c = *t; 1699 while (c == ' ' || c == '\t' ) 1700 c = *++t; 1701 if (!c) { 1702 t = 0; 1703 return 0; 1704 } 1705 q = t; 1706 if (c == '\'') { 1707 c = *++t; 1708 q = t; 1709 while (c && c != '\'') 1710 c = *++t; 1711 if (!c) /* unterminated string */ 1712 q = t = 0; 1713 else 1714 *t++ = 0; 1715 } else { 1716 while (c && c != ' ' && c != '\t' ) 1717 c = *++t; 1718 *t++ = 0; 1719 if (!c) 1720 t = 0; 1721 } 1722 return q; 1723 } 1724 1725 #ifdef LOGIN_CAP 1726 static void 1727 setprocresources(const char *cname) 1728 { 1729 login_cap_t *lc; 1730 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 1731 setusercontext(lc, (struct passwd*)NULL, 0, 1732 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 1733 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 1734 login_close(lc); 1735 } 1736 } 1737 #endif 1738