1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Donn Seeley at Berkeley Software Design, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef lint 36 static const char copyright[] = 37 "@(#) Copyright (c) 1991, 1993\n\ 38 The Regents of the University of California. All rights reserved.\n"; 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93"; 44 #endif 45 static const char rcsid[] = 46 "$FreeBSD$"; 47 #endif /* not lint */ 48 49 #include <sys/param.h> 50 #include <sys/ioctl.h> 51 #include <sys/mman.h> 52 #include <sys/mount.h> 53 #include <sys/sysctl.h> 54 #include <sys/wait.h> 55 #include <sys/stat.h> 56 #include <sys/uio.h> 57 58 #include <db.h> 59 #include <errno.h> 60 #include <fcntl.h> 61 #include <kenv.h> 62 #include <libutil.h> 63 #include <paths.h> 64 #include <signal.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <syslog.h> 69 #include <time.h> 70 #include <ttyent.h> 71 #include <unistd.h> 72 #include <sys/reboot.h> 73 #include <err.h> 74 75 #include <stdarg.h> 76 77 #ifdef SECURE 78 #include <pwd.h> 79 #endif 80 81 #ifdef LOGIN_CAP 82 #include <login_cap.h> 83 #endif 84 85 #include "mntopts.h" 86 #include "pathnames.h" 87 88 /* 89 * Sleep times; used to prevent thrashing. 90 */ 91 #define GETTY_SPACING 5 /* N secs minimum getty spacing */ 92 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 93 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ 94 #define WINDOW_WAIT 3 /* wait N secs after starting window */ 95 #define STALL_TIMEOUT 30 /* wait N secs after warning */ 96 #define DEATH_WATCH 10 /* wait N secs for procs to die */ 97 #define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */ 98 #define RESOURCE_RC "daemon" 99 #define RESOURCE_WINDOW "default" 100 #define RESOURCE_GETTY "default" 101 102 static void handle(sig_t, ...); 103 static void delset(sigset_t *, ...); 104 105 static void stall(const char *, ...) __printflike(1, 2); 106 static void warning(const char *, ...) __printflike(1, 2); 107 static void emergency(const char *, ...) __printflike(1, 2); 108 static void disaster(int); 109 static void badsys(int); 110 static void revoke_ttys(void); 111 static int runshutdown(void); 112 static char *strk(char *); 113 114 /* 115 * We really need a recursive typedef... 116 * The following at least guarantees that the return type of (*state_t)() 117 * is sufficiently wide to hold a function pointer. 118 */ 119 typedef long (*state_func_t)(void); 120 typedef state_func_t (*state_t)(void); 121 122 static state_func_t single_user(void); 123 static state_func_t runcom(void); 124 static state_func_t read_ttys(void); 125 static state_func_t multi_user(void); 126 static state_func_t clean_ttys(void); 127 static state_func_t catatonia(void); 128 static state_func_t death(void); 129 static state_func_t death_single(void); 130 static state_func_t reroot(void); 131 static state_func_t reroot_phase_two(void); 132 133 static state_func_t run_script(const char *); 134 135 static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 136 #define FALSE 0 137 #define TRUE 1 138 139 static int Reboot = FALSE; 140 static int howto = RB_AUTOBOOT; 141 142 static int devfs; 143 static char *init_path_argv0; 144 145 static void transition(state_t); 146 static state_t requested_transition; 147 static state_t current_state = death_single; 148 149 static void open_console(void); 150 static const char *get_shell(void); 151 static void write_stderr(const char *message); 152 153 typedef struct init_session { 154 pid_t se_process; /* controlling process */ 155 time_t se_started; /* used to avoid thrashing */ 156 int se_flags; /* status of session */ 157 #define SE_SHUTDOWN 0x1 /* session won't be restarted */ 158 #define SE_PRESENT 0x2 /* session is in /etc/ttys */ 159 int se_nspace; /* spacing count */ 160 char *se_device; /* filename of port */ 161 char *se_getty; /* what to run on that port */ 162 char *se_getty_argv_space; /* pre-parsed argument array space */ 163 char **se_getty_argv; /* pre-parsed argument array */ 164 char *se_window; /* window system (started only once) */ 165 char *se_window_argv_space; /* pre-parsed argument array space */ 166 char **se_window_argv; /* pre-parsed argument array */ 167 char *se_type; /* default terminal type */ 168 struct init_session *se_prev; 169 struct init_session *se_next; 170 } session_t; 171 172 static void free_session(session_t *); 173 static session_t *new_session(session_t *, struct ttyent *); 174 static session_t *sessions; 175 176 static char **construct_argv(char *); 177 static void start_window_system(session_t *); 178 static void collect_child(pid_t); 179 static pid_t start_getty(session_t *); 180 static void transition_handler(int); 181 static void alrm_handler(int); 182 static void setsecuritylevel(int); 183 static int getsecuritylevel(void); 184 static int setupargv(session_t *, struct ttyent *); 185 #ifdef LOGIN_CAP 186 static void setprocresources(const char *); 187 #endif 188 static int clang; 189 190 static int start_session_db(void); 191 static void add_session(session_t *); 192 static void del_session(session_t *); 193 static session_t *find_session(pid_t); 194 static DB *session_db; 195 196 /* 197 * The mother of all processes. 198 */ 199 int 200 main(int argc, char *argv[]) 201 { 202 state_t initial_transition = runcom; 203 char kenv_value[PATH_MAX]; 204 int c, error; 205 struct sigaction sa; 206 sigset_t mask; 207 208 /* Dispose of random users. */ 209 if (getuid() != 0) 210 errx(1, "%s", strerror(EPERM)); 211 212 /* System V users like to reexec init. */ 213 if (getpid() != 1) { 214 #ifdef COMPAT_SYSV_INIT 215 /* So give them what they want */ 216 if (argc > 1) { 217 if (strlen(argv[1]) == 1) { 218 char runlevel = *argv[1]; 219 int sig; 220 221 switch (runlevel) { 222 case '0': /* halt + poweroff */ 223 sig = SIGUSR2; 224 break; 225 case '1': /* single-user */ 226 sig = SIGTERM; 227 break; 228 case '6': /* reboot */ 229 sig = SIGINT; 230 break; 231 case 'c': /* block further logins */ 232 sig = SIGTSTP; 233 break; 234 case 'q': /* rescan /etc/ttys */ 235 sig = SIGHUP; 236 break; 237 case 'r': /* remount root */ 238 sig = SIGEMT; 239 break; 240 default: 241 goto invalid; 242 } 243 kill(1, sig); 244 _exit(0); 245 } else 246 invalid: 247 errx(1, "invalid run-level ``%s''", argv[1]); 248 } else 249 #endif 250 errx(1, "already running"); 251 } 252 253 init_path_argv0 = strdup(argv[0]); 254 if (init_path_argv0 == NULL) 255 err(1, "strdup"); 256 257 /* 258 * Note that this does NOT open a file... 259 * Does 'init' deserve its own facility number? 260 */ 261 openlog("init", LOG_CONS, LOG_AUTH); 262 263 /* 264 * Create an initial session. 265 */ 266 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 267 warning("initial setsid() failed: %m"); 268 269 /* 270 * Establish an initial user so that programs running 271 * single user do not freak out and die (like passwd). 272 */ 273 if (setlogin("root") < 0) 274 warning("setlogin() failed: %m"); 275 276 /* 277 * This code assumes that we always get arguments through flags, 278 * never through bits set in some random machine register. 279 */ 280 while ((c = getopt(argc, argv, "dsfr")) != -1) 281 switch (c) { 282 case 'd': 283 devfs = 1; 284 break; 285 case 's': 286 initial_transition = single_user; 287 break; 288 case 'f': 289 runcom_mode = FASTBOOT; 290 break; 291 case 'r': 292 initial_transition = reroot_phase_two; 293 break; 294 default: 295 warning("unrecognized flag '-%c'", c); 296 break; 297 } 298 299 if (optind != argc) 300 warning("ignoring excess arguments"); 301 302 /* 303 * We catch or block signals rather than ignore them, 304 * so that they get reset on exec. 305 */ 306 handle(badsys, SIGSYS, 0); 307 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 308 SIGXFSZ, 0); 309 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 310 SIGUSR1, SIGUSR2, SIGWINCH, 0); 311 handle(alrm_handler, SIGALRM, 0); 312 sigfillset(&mask); 313 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 314 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 315 SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0); 316 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 317 sigemptyset(&sa.sa_mask); 318 sa.sa_flags = 0; 319 sa.sa_handler = SIG_IGN; 320 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 321 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 322 323 /* 324 * Paranoia. 325 */ 326 close(0); 327 close(1); 328 close(2); 329 330 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 331 state_func_t next_transition; 332 333 if ((next_transition = run_script(kenv_value)) != NULL) 334 initial_transition = (state_t) next_transition; 335 } 336 337 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 338 if (chdir(kenv_value) != 0 || chroot(".") != 0) 339 warning("Can't chroot to %s: %m", kenv_value); 340 } 341 342 /* 343 * Additional check if devfs needs to be mounted: 344 * If "/" and "/dev" have the same device number, 345 * then it hasn't been mounted yet. 346 */ 347 if (!devfs) { 348 struct stat stst; 349 dev_t root_devno; 350 351 stat("/", &stst); 352 root_devno = stst.st_dev; 353 if (stat("/dev", &stst) != 0) 354 warning("Can't stat /dev: %m"); 355 else if (stst.st_dev == root_devno) 356 devfs++; 357 } 358 359 if (devfs) { 360 struct iovec iov[4]; 361 char *s; 362 int i; 363 364 char _fstype[] = "fstype"; 365 char _devfs[] = "devfs"; 366 char _fspath[] = "fspath"; 367 char _path_dev[]= _PATH_DEV; 368 369 iov[0].iov_base = _fstype; 370 iov[0].iov_len = sizeof(_fstype); 371 iov[1].iov_base = _devfs; 372 iov[1].iov_len = sizeof(_devfs); 373 iov[2].iov_base = _fspath; 374 iov[2].iov_len = sizeof(_fspath); 375 /* 376 * Try to avoid the trailing slash in _PATH_DEV. 377 * Be *very* defensive. 378 */ 379 s = strdup(_PATH_DEV); 380 if (s != NULL) { 381 i = strlen(s); 382 if (i > 0 && s[i - 1] == '/') 383 s[i - 1] = '\0'; 384 iov[3].iov_base = s; 385 iov[3].iov_len = strlen(s) + 1; 386 } else { 387 iov[3].iov_base = _path_dev; 388 iov[3].iov_len = sizeof(_path_dev); 389 } 390 nmount(iov, 4, 0); 391 if (s != NULL) 392 free(s); 393 } 394 395 if (initial_transition != reroot_phase_two) { 396 /* 397 * Unmount reroot leftovers. This runs after init(8) 398 * gets reexecuted after reroot_phase_two() is done. 399 */ 400 error = unmount(_PATH_REROOT, MNT_FORCE); 401 if (error != 0 && errno != EINVAL) 402 warning("Cannot unmount %s: %m", _PATH_REROOT); 403 } 404 405 /* 406 * Start the state machine. 407 */ 408 transition(initial_transition); 409 410 /* 411 * Should never reach here. 412 */ 413 return 1; 414 } 415 416 /* 417 * Associate a function with a signal handler. 418 */ 419 static void 420 handle(sig_t handler, ...) 421 { 422 int sig; 423 struct sigaction sa; 424 sigset_t mask_everything; 425 va_list ap; 426 va_start(ap, handler); 427 428 sa.sa_handler = handler; 429 sigfillset(&mask_everything); 430 431 while ((sig = va_arg(ap, int)) != 0) { 432 sa.sa_mask = mask_everything; 433 /* XXX SA_RESTART? */ 434 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 435 sigaction(sig, &sa, (struct sigaction *) 0); 436 } 437 va_end(ap); 438 } 439 440 /* 441 * Delete a set of signals from a mask. 442 */ 443 static void 444 delset(sigset_t *maskp, ...) 445 { 446 int sig; 447 va_list ap; 448 va_start(ap, maskp); 449 450 while ((sig = va_arg(ap, int)) != 0) 451 sigdelset(maskp, sig); 452 va_end(ap); 453 } 454 455 /* 456 * Log a message and sleep for a while (to give someone an opportunity 457 * to read it and to save log or hardcopy output if the problem is chronic). 458 * NB: should send a message to the session logger to avoid blocking. 459 */ 460 static void 461 stall(const char *message, ...) 462 { 463 va_list ap; 464 va_start(ap, message); 465 466 vsyslog(LOG_ALERT, message, ap); 467 va_end(ap); 468 sleep(STALL_TIMEOUT); 469 } 470 471 /* 472 * Like stall(), but doesn't sleep. 473 * If cpp had variadic macros, the two functions could be #defines for another. 474 * NB: should send a message to the session logger to avoid blocking. 475 */ 476 static void 477 warning(const char *message, ...) 478 { 479 va_list ap; 480 va_start(ap, message); 481 482 vsyslog(LOG_ALERT, message, ap); 483 va_end(ap); 484 } 485 486 /* 487 * Log an emergency message. 488 * NB: should send a message to the session logger to avoid blocking. 489 */ 490 static void 491 emergency(const char *message, ...) 492 { 493 va_list ap; 494 va_start(ap, message); 495 496 vsyslog(LOG_EMERG, message, ap); 497 va_end(ap); 498 } 499 500 /* 501 * Catch a SIGSYS signal. 502 * 503 * These may arise if a system does not support sysctl. 504 * We tolerate up to 25 of these, then throw in the towel. 505 */ 506 static void 507 badsys(int sig) 508 { 509 static int badcount = 0; 510 511 if (badcount++ < 25) 512 return; 513 disaster(sig); 514 } 515 516 /* 517 * Catch an unexpected signal. 518 */ 519 static void 520 disaster(int sig) 521 { 522 523 emergency("fatal signal: %s", 524 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 525 526 sleep(STALL_TIMEOUT); 527 _exit(sig); /* reboot */ 528 } 529 530 /* 531 * Get the security level of the kernel. 532 */ 533 static int 534 getsecuritylevel(void) 535 { 536 #ifdef KERN_SECURELVL 537 int name[2], curlevel; 538 size_t len; 539 540 name[0] = CTL_KERN; 541 name[1] = KERN_SECURELVL; 542 len = sizeof curlevel; 543 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 544 emergency("cannot get kernel security level: %s", 545 strerror(errno)); 546 return (-1); 547 } 548 return (curlevel); 549 #else 550 return (-1); 551 #endif 552 } 553 554 /* 555 * Set the security level of the kernel. 556 */ 557 static void 558 setsecuritylevel(int newlevel) 559 { 560 #ifdef KERN_SECURELVL 561 int name[2], curlevel; 562 563 curlevel = getsecuritylevel(); 564 if (newlevel == curlevel) 565 return; 566 name[0] = CTL_KERN; 567 name[1] = KERN_SECURELVL; 568 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 569 emergency( 570 "cannot change kernel security level from %d to %d: %s", 571 curlevel, newlevel, strerror(errno)); 572 return; 573 } 574 #ifdef SECURE 575 warning("kernel security level changed from %d to %d", 576 curlevel, newlevel); 577 #endif 578 #endif 579 } 580 581 /* 582 * Change states in the finite state machine. 583 * The initial state is passed as an argument. 584 */ 585 static void 586 transition(state_t s) 587 { 588 589 current_state = s; 590 for (;;) 591 current_state = (state_t) (*current_state)(); 592 } 593 594 /* 595 * Start a session and allocate a controlling terminal. 596 * Only called by children of init after forking. 597 */ 598 static void 599 open_console(void) 600 { 601 int fd; 602 603 /* 604 * Try to open /dev/console. Open the device with O_NONBLOCK to 605 * prevent potential blocking on a carrier. 606 */ 607 revoke(_PATH_CONSOLE); 608 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 609 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 610 if (login_tty(fd) == 0) 611 return; 612 close(fd); 613 } 614 615 /* No luck. Log output to file if possible. */ 616 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 617 stall("cannot open null device."); 618 _exit(1); 619 } 620 if (fd != STDIN_FILENO) { 621 dup2(fd, STDIN_FILENO); 622 close(fd); 623 } 624 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 625 if (fd == -1) 626 dup2(STDIN_FILENO, STDOUT_FILENO); 627 else if (fd != STDOUT_FILENO) { 628 dup2(fd, STDOUT_FILENO); 629 close(fd); 630 } 631 dup2(STDOUT_FILENO, STDERR_FILENO); 632 } 633 634 static const char * 635 get_shell(void) 636 { 637 static char kenv_value[PATH_MAX]; 638 639 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 640 return kenv_value; 641 else 642 return _PATH_BSHELL; 643 } 644 645 static void 646 write_stderr(const char *message) 647 { 648 649 write(STDERR_FILENO, message, strlen(message)); 650 } 651 652 static int 653 read_file(const char *path, void **bufp, size_t *bufsizep) 654 { 655 struct stat sb; 656 size_t bufsize; 657 void *buf; 658 ssize_t nbytes; 659 int error, fd; 660 661 fd = open(path, O_RDONLY); 662 if (fd < 0) { 663 emergency("%s: %s", path, strerror(errno)); 664 return (-1); 665 } 666 667 error = fstat(fd, &sb); 668 if (error != 0) { 669 emergency("fstat: %s", strerror(errno)); 670 close(fd); 671 return (error); 672 } 673 674 bufsize = sb.st_size; 675 buf = malloc(bufsize); 676 if (buf == NULL) { 677 emergency("malloc: %s", strerror(errno)); 678 close(fd); 679 return (error); 680 } 681 682 nbytes = read(fd, buf, bufsize); 683 if (nbytes != (ssize_t)bufsize) { 684 emergency("read: %s", strerror(errno)); 685 close(fd); 686 free(buf); 687 return (error); 688 } 689 690 error = close(fd); 691 if (error != 0) { 692 emergency("close: %s", strerror(errno)); 693 free(buf); 694 return (error); 695 } 696 697 *bufp = buf; 698 *bufsizep = bufsize; 699 700 return (0); 701 } 702 703 static int 704 create_file(const char *path, const void *buf, size_t bufsize) 705 { 706 ssize_t nbytes; 707 int error, fd; 708 709 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 710 if (fd < 0) { 711 emergency("%s: %s", path, strerror(errno)); 712 return (-1); 713 } 714 715 nbytes = write(fd, buf, bufsize); 716 if (nbytes != (ssize_t)bufsize) { 717 emergency("write: %s", strerror(errno)); 718 close(fd); 719 return (-1); 720 } 721 722 error = close(fd); 723 if (error != 0) { 724 emergency("close: %s", strerror(errno)); 725 return (-1); 726 } 727 728 return (0); 729 } 730 731 static int 732 mount_tmpfs(const char *fspath) 733 { 734 struct iovec *iov; 735 char errmsg[255]; 736 int error, iovlen; 737 738 iov = NULL; 739 iovlen = 0; 740 memset(errmsg, 0, sizeof(errmsg)); 741 build_iovec(&iov, &iovlen, "fstype", 742 __DECONST(void *, "tmpfs"), (size_t)-1); 743 build_iovec(&iov, &iovlen, "fspath", 744 __DECONST(void *, fspath), (size_t)-1); 745 build_iovec(&iov, &iovlen, "errmsg", 746 errmsg, sizeof(errmsg)); 747 748 error = nmount(iov, iovlen, 0); 749 if (error != 0) { 750 if (*errmsg != '\0') { 751 emergency("cannot mount tmpfs on %s: %s: %s", 752 fspath, errmsg, strerror(errno)); 753 } else { 754 emergency("cannot mount tmpfs on %s: %s", 755 fspath, strerror(errno)); 756 } 757 return (error); 758 } 759 return (0); 760 } 761 762 static state_func_t 763 reroot(void) 764 { 765 void *buf; 766 size_t bufsize; 767 int error; 768 769 buf = NULL; 770 bufsize = 0; 771 772 revoke_ttys(); 773 runshutdown(); 774 775 /* 776 * Make sure nobody can interfere with our scheme. 777 * Ignore ESRCH, which can apparently happen when 778 * there are no processes to kill. 779 */ 780 error = kill(-1, SIGKILL); 781 if (error != 0 && errno != ESRCH) { 782 emergency("kill(2) failed: %s", strerror(errno)); 783 goto out; 784 } 785 786 /* 787 * Copy the init binary into tmpfs, so that we can unmount 788 * the old rootfs without committing suicide. 789 */ 790 error = read_file(init_path_argv0, &buf, &bufsize); 791 if (error != 0) 792 goto out; 793 error = mount_tmpfs(_PATH_REROOT); 794 if (error != 0) 795 goto out; 796 error = create_file(_PATH_REROOT_INIT, buf, bufsize); 797 if (error != 0) 798 goto out; 799 800 /* 801 * Execute the temporary init. 802 */ 803 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); 804 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno)); 805 806 out: 807 emergency("reroot failed; going to single user mode"); 808 free(buf); 809 return (state_func_t) single_user; 810 } 811 812 static state_func_t 813 reroot_phase_two(void) 814 { 815 char init_path[PATH_MAX], *path, *path_component; 816 size_t init_path_len; 817 int nbytes, error; 818 819 /* 820 * Ask the kernel to mount the new rootfs. 821 */ 822 error = reboot(RB_REROOT); 823 if (error != 0) { 824 emergency("RB_REBOOT failed: %s", strerror(errno)); 825 goto out; 826 } 827 828 /* 829 * Figure out where the destination init(8) binary is. Note that 830 * the path could be different than what we've started with. Use 831 * the value from kenv, if set, or the one from sysctl otherwise. 832 * The latter defaults to a hardcoded value, but can be overridden 833 * by a build time option. 834 */ 835 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 836 if (nbytes <= 0) { 837 init_path_len = sizeof(init_path); 838 error = sysctlbyname("kern.init_path", 839 init_path, &init_path_len, NULL, 0); 840 if (error != 0) { 841 emergency("failed to retrieve kern.init_path: %s", 842 strerror(errno)); 843 goto out; 844 } 845 } 846 847 /* 848 * Repeat the init search logic from sys/kern/init_path.c 849 */ 850 path_component = init_path; 851 while ((path = strsep(&path_component, ":")) != NULL) { 852 /* 853 * Execute init(8) from the new rootfs. 854 */ 855 execl(path, path, NULL); 856 } 857 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 858 859 out: 860 emergency("reroot failed; going to single user mode"); 861 return (state_func_t) single_user; 862 } 863 864 /* 865 * Bring the system up single user. 866 */ 867 static state_func_t 868 single_user(void) 869 { 870 pid_t pid, wpid; 871 int status; 872 sigset_t mask; 873 const char *shell; 874 char *argv[2]; 875 struct timeval tv, tn; 876 #ifdef SECURE 877 struct ttyent *typ; 878 struct passwd *pp; 879 static const char banner[] = 880 "Enter root password, or ^D to go multi-user\n"; 881 char *clear, *password; 882 #endif 883 #ifdef DEBUGSHELL 884 char altshell[128]; 885 #endif 886 887 if (Reboot) { 888 /* Instead of going single user, let's reboot the machine */ 889 sync(); 890 if (reboot(howto) == -1) { 891 emergency("reboot(%#x) failed, %s", howto, 892 strerror(errno)); 893 _exit(1); /* panic and reboot */ 894 } 895 warning("reboot(%#x) returned", howto); 896 _exit(0); /* panic as well */ 897 } 898 899 shell = get_shell(); 900 901 if ((pid = fork()) == 0) { 902 /* 903 * Start the single user session. 904 */ 905 open_console(); 906 907 #ifdef SECURE 908 /* 909 * Check the root password. 910 * We don't care if the console is 'on' by default; 911 * it's the only tty that can be 'off' and 'secure'. 912 */ 913 typ = getttynam("console"); 914 pp = getpwnam("root"); 915 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 916 pp && *pp->pw_passwd) { 917 write_stderr(banner); 918 for (;;) { 919 clear = getpass("Password:"); 920 if (clear == NULL || *clear == '\0') 921 _exit(0); 922 password = crypt(clear, pp->pw_passwd); 923 bzero(clear, _PASSWORD_LEN); 924 if (password != NULL && 925 strcmp(password, pp->pw_passwd) == 0) 926 break; 927 warning("single-user login failed\n"); 928 } 929 } 930 endttyent(); 931 endpwent(); 932 #endif /* SECURE */ 933 934 #ifdef DEBUGSHELL 935 { 936 char *cp = altshell; 937 int num; 938 939 #define SHREQUEST "Enter full pathname of shell or RETURN for " 940 write_stderr(SHREQUEST); 941 write_stderr(shell); 942 write_stderr(": "); 943 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 944 num != 0 && *cp != '\n' && cp < &altshell[127]) 945 cp++; 946 *cp = '\0'; 947 if (altshell[0] != '\0') 948 shell = altshell; 949 } 950 #endif /* DEBUGSHELL */ 951 952 /* 953 * Unblock signals. 954 * We catch all the interesting ones, 955 * and those are reset to SIG_DFL on exec. 956 */ 957 sigemptyset(&mask); 958 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 959 960 /* 961 * Fire off a shell. 962 * If the default one doesn't work, try the Bourne shell. 963 */ 964 965 char name[] = "-sh"; 966 967 argv[0] = name; 968 argv[1] = 0; 969 execv(shell, argv); 970 emergency("can't exec %s for single user: %m", shell); 971 execv(_PATH_BSHELL, argv); 972 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 973 sleep(STALL_TIMEOUT); 974 _exit(1); 975 } 976 977 if (pid == -1) { 978 /* 979 * We are seriously hosed. Do our best. 980 */ 981 emergency("can't fork single-user shell, trying again"); 982 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 983 continue; 984 return (state_func_t) single_user; 985 } 986 987 requested_transition = 0; 988 do { 989 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 990 collect_child(wpid); 991 if (wpid == -1) { 992 if (errno == EINTR) 993 continue; 994 warning("wait for single-user shell failed: %m; restarting"); 995 return (state_func_t) single_user; 996 } 997 if (wpid == pid && WIFSTOPPED(status)) { 998 warning("init: shell stopped, restarting\n"); 999 kill(pid, SIGCONT); 1000 wpid = -1; 1001 } 1002 } while (wpid != pid && !requested_transition); 1003 1004 if (requested_transition) 1005 return (state_func_t) requested_transition; 1006 1007 if (!WIFEXITED(status)) { 1008 if (WTERMSIG(status) == SIGKILL) { 1009 /* 1010 * reboot(8) killed shell? 1011 */ 1012 warning("single user shell terminated."); 1013 gettimeofday(&tv, NULL); 1014 tn = tv; 1015 tv.tv_sec += STALL_TIMEOUT; 1016 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == 1017 tn.tv_sec && tv.tv_usec > tn.tv_usec)) { 1018 sleep(1); 1019 gettimeofday(&tn, NULL); 1020 } 1021 _exit(0); 1022 } else { 1023 warning("single user shell terminated, restarting"); 1024 return (state_func_t) single_user; 1025 } 1026 } 1027 1028 runcom_mode = FASTBOOT; 1029 return (state_func_t) runcom; 1030 } 1031 1032 /* 1033 * Run the system startup script. 1034 */ 1035 static state_func_t 1036 runcom(void) 1037 { 1038 state_func_t next_transition; 1039 1040 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL) 1041 return next_transition; 1042 1043 runcom_mode = AUTOBOOT; /* the default */ 1044 return (state_func_t) read_ttys; 1045 } 1046 1047 /* 1048 * Run a shell script. 1049 * Returns 0 on success, otherwise the next transition to enter: 1050 * - single_user if fork/execv/waitpid failed, or if the script 1051 * terminated with a signal or exit code != 0. 1052 * - death_single if a SIGTERM was delivered to init(8). 1053 */ 1054 static state_func_t 1055 run_script(const char *script) 1056 { 1057 pid_t pid, wpid; 1058 int status; 1059 char *argv[4]; 1060 const char *shell; 1061 struct sigaction sa; 1062 1063 shell = get_shell(); 1064 1065 if ((pid = fork()) == 0) { 1066 sigemptyset(&sa.sa_mask); 1067 sa.sa_flags = 0; 1068 sa.sa_handler = SIG_IGN; 1069 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1070 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1071 1072 open_console(); 1073 1074 char _sh[] = "sh"; 1075 char _autoboot[] = "autoboot"; 1076 1077 argv[0] = _sh; 1078 argv[1] = __DECONST(char *, script); 1079 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1080 argv[3] = 0; 1081 1082 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1083 1084 #ifdef LOGIN_CAP 1085 setprocresources(RESOURCE_RC); 1086 #endif 1087 execv(shell, argv); 1088 stall("can't exec %s for %s: %m", shell, script); 1089 _exit(1); /* force single user mode */ 1090 } 1091 1092 if (pid == -1) { 1093 emergency("can't fork for %s on %s: %m", shell, script); 1094 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1095 continue; 1096 sleep(STALL_TIMEOUT); 1097 return (state_func_t) single_user; 1098 } 1099 1100 /* 1101 * Copied from single_user(). This is a bit paranoid. 1102 */ 1103 requested_transition = 0; 1104 do { 1105 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1106 collect_child(wpid); 1107 if (wpid == -1) { 1108 if (requested_transition == death_single || 1109 requested_transition == reroot) 1110 return (state_func_t) requested_transition; 1111 if (errno == EINTR) 1112 continue; 1113 warning("wait for %s on %s failed: %m; going to " 1114 "single user mode", shell, script); 1115 return (state_func_t) single_user; 1116 } 1117 if (wpid == pid && WIFSTOPPED(status)) { 1118 warning("init: %s on %s stopped, restarting\n", 1119 shell, script); 1120 kill(pid, SIGCONT); 1121 wpid = -1; 1122 } 1123 } while (wpid != pid); 1124 1125 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1126 requested_transition == catatonia) { 1127 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1128 sigset_t s; 1129 1130 sigfillset(&s); 1131 for (;;) 1132 sigsuspend(&s); 1133 } 1134 1135 if (!WIFEXITED(status)) { 1136 warning("%s on %s terminated abnormally, going to single " 1137 "user mode", shell, script); 1138 return (state_func_t) single_user; 1139 } 1140 1141 if (WEXITSTATUS(status)) 1142 return (state_func_t) single_user; 1143 1144 return (state_func_t) 0; 1145 } 1146 1147 /* 1148 * Open the session database. 1149 * 1150 * NB: We could pass in the size here; is it necessary? 1151 */ 1152 static int 1153 start_session_db(void) 1154 { 1155 if (session_db && (*session_db->close)(session_db)) 1156 emergency("session database close: %s", strerror(errno)); 1157 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 1158 emergency("session database open: %s", strerror(errno)); 1159 return (1); 1160 } 1161 return (0); 1162 1163 } 1164 1165 /* 1166 * Add a new login session. 1167 */ 1168 static void 1169 add_session(session_t *sp) 1170 { 1171 DBT key; 1172 DBT data; 1173 1174 key.data = &sp->se_process; 1175 key.size = sizeof sp->se_process; 1176 data.data = &sp; 1177 data.size = sizeof sp; 1178 1179 if ((*session_db->put)(session_db, &key, &data, 0)) 1180 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1181 } 1182 1183 /* 1184 * Delete an old login session. 1185 */ 1186 static void 1187 del_session(session_t *sp) 1188 { 1189 DBT key; 1190 1191 key.data = &sp->se_process; 1192 key.size = sizeof sp->se_process; 1193 1194 if ((*session_db->del)(session_db, &key, 0)) 1195 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1196 } 1197 1198 /* 1199 * Look up a login session by pid. 1200 */ 1201 static session_t * 1202 find_session(pid_t pid) 1203 { 1204 DBT key; 1205 DBT data; 1206 session_t *ret; 1207 1208 key.data = &pid; 1209 key.size = sizeof pid; 1210 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1211 return 0; 1212 bcopy(data.data, (char *)&ret, sizeof(ret)); 1213 return ret; 1214 } 1215 1216 /* 1217 * Construct an argument vector from a command line. 1218 */ 1219 static char ** 1220 construct_argv(char *command) 1221 { 1222 int argc = 0; 1223 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1224 * sizeof (char *)); 1225 1226 if ((argv[argc++] = strk(command)) == NULL) { 1227 free(argv); 1228 return (NULL); 1229 } 1230 while ((argv[argc++] = strk((char *) 0)) != NULL) 1231 continue; 1232 return argv; 1233 } 1234 1235 /* 1236 * Deallocate a session descriptor. 1237 */ 1238 static void 1239 free_session(session_t *sp) 1240 { 1241 free(sp->se_device); 1242 if (sp->se_getty) { 1243 free(sp->se_getty); 1244 free(sp->se_getty_argv_space); 1245 free(sp->se_getty_argv); 1246 } 1247 if (sp->se_window) { 1248 free(sp->se_window); 1249 free(sp->se_window_argv_space); 1250 free(sp->se_window_argv); 1251 } 1252 if (sp->se_type) 1253 free(sp->se_type); 1254 free(sp); 1255 } 1256 1257 /* 1258 * Allocate a new session descriptor. 1259 * Mark it SE_PRESENT. 1260 */ 1261 static session_t * 1262 new_session(session_t *sprev, struct ttyent *typ) 1263 { 1264 session_t *sp; 1265 int fd; 1266 1267 if ((typ->ty_status & TTY_ON) == 0 || 1268 typ->ty_name == 0 || 1269 typ->ty_getty == 0) 1270 return 0; 1271 1272 sp = (session_t *) calloc(1, sizeof (session_t)); 1273 1274 sp->se_flags |= SE_PRESENT; 1275 1276 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0) 1277 err(1, "asprintf"); 1278 1279 /* 1280 * Attempt to open the device, if we get "device not configured" 1281 * then don't add the device to the session list. 1282 */ 1283 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) { 1284 if (errno == ENXIO) { 1285 free_session(sp); 1286 return (0); 1287 } 1288 } else 1289 close(fd); 1290 1291 if (setupargv(sp, typ) == 0) { 1292 free_session(sp); 1293 return (0); 1294 } 1295 1296 sp->se_next = 0; 1297 if (sprev == NULL) { 1298 sessions = sp; 1299 sp->se_prev = 0; 1300 } else { 1301 sprev->se_next = sp; 1302 sp->se_prev = sprev; 1303 } 1304 1305 return sp; 1306 } 1307 1308 /* 1309 * Calculate getty and if useful window argv vectors. 1310 */ 1311 static int 1312 setupargv(session_t *sp, struct ttyent *typ) 1313 { 1314 1315 if (sp->se_getty) { 1316 free(sp->se_getty); 1317 free(sp->se_getty_argv_space); 1318 free(sp->se_getty_argv); 1319 } 1320 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0) 1321 err(1, "asprintf"); 1322 sp->se_getty_argv_space = strdup(sp->se_getty); 1323 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1324 if (sp->se_getty_argv == NULL) { 1325 warning("can't parse getty for port %s", sp->se_device); 1326 free(sp->se_getty); 1327 free(sp->se_getty_argv_space); 1328 sp->se_getty = sp->se_getty_argv_space = 0; 1329 return (0); 1330 } 1331 if (sp->se_window) { 1332 free(sp->se_window); 1333 free(sp->se_window_argv_space); 1334 free(sp->se_window_argv); 1335 } 1336 sp->se_window = sp->se_window_argv_space = 0; 1337 sp->se_window_argv = 0; 1338 if (typ->ty_window) { 1339 sp->se_window = strdup(typ->ty_window); 1340 sp->se_window_argv_space = strdup(sp->se_window); 1341 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1342 if (sp->se_window_argv == NULL) { 1343 warning("can't parse window for port %s", 1344 sp->se_device); 1345 free(sp->se_window_argv_space); 1346 free(sp->se_window); 1347 sp->se_window = sp->se_window_argv_space = 0; 1348 return (0); 1349 } 1350 } 1351 if (sp->se_type) 1352 free(sp->se_type); 1353 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1354 return (1); 1355 } 1356 1357 /* 1358 * Walk the list of ttys and create sessions for each active line. 1359 */ 1360 static state_func_t 1361 read_ttys(void) 1362 { 1363 session_t *sp, *snext; 1364 struct ttyent *typ; 1365 1366 /* 1367 * Destroy any previous session state. 1368 * There shouldn't be any, but just in case... 1369 */ 1370 for (sp = sessions; sp; sp = snext) { 1371 snext = sp->se_next; 1372 free_session(sp); 1373 } 1374 sessions = 0; 1375 if (start_session_db()) 1376 return (state_func_t) single_user; 1377 1378 /* 1379 * Allocate a session entry for each active port. 1380 * Note that sp starts at 0. 1381 */ 1382 while ((typ = getttyent()) != NULL) 1383 if ((snext = new_session(sp, typ)) != NULL) 1384 sp = snext; 1385 1386 endttyent(); 1387 1388 return (state_func_t) multi_user; 1389 } 1390 1391 /* 1392 * Start a window system running. 1393 */ 1394 static void 1395 start_window_system(session_t *sp) 1396 { 1397 pid_t pid; 1398 sigset_t mask; 1399 char term[64], *env[2]; 1400 int status; 1401 1402 if ((pid = fork()) == -1) { 1403 emergency("can't fork for window system on port %s: %m", 1404 sp->se_device); 1405 /* hope that getty fails and we can try again */ 1406 return; 1407 } 1408 if (pid) { 1409 waitpid(-1, &status, 0); 1410 return; 1411 } 1412 1413 /* reparent window process to the init to not make a zombie on exit */ 1414 if ((pid = fork()) == -1) { 1415 emergency("can't fork for window system on port %s: %m", 1416 sp->se_device); 1417 _exit(1); 1418 } 1419 if (pid) 1420 _exit(0); 1421 1422 sigemptyset(&mask); 1423 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1424 1425 if (setsid() < 0) 1426 emergency("setsid failed (window) %m"); 1427 1428 #ifdef LOGIN_CAP 1429 setprocresources(RESOURCE_WINDOW); 1430 #endif 1431 if (sp->se_type) { 1432 /* Don't use malloc after fork */ 1433 strcpy(term, "TERM="); 1434 strlcat(term, sp->se_type, sizeof(term)); 1435 env[0] = term; 1436 env[1] = 0; 1437 } 1438 else 1439 env[0] = 0; 1440 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1441 stall("can't exec window system '%s' for port %s: %m", 1442 sp->se_window_argv[0], sp->se_device); 1443 _exit(1); 1444 } 1445 1446 /* 1447 * Start a login session running. 1448 */ 1449 static pid_t 1450 start_getty(session_t *sp) 1451 { 1452 pid_t pid; 1453 sigset_t mask; 1454 time_t current_time = time((time_t *) 0); 1455 int too_quick = 0; 1456 char term[64], *env[2]; 1457 1458 if (current_time >= sp->se_started && 1459 current_time - sp->se_started < GETTY_SPACING) { 1460 if (++sp->se_nspace > GETTY_NSPACE) { 1461 sp->se_nspace = 0; 1462 too_quick = 1; 1463 } 1464 } else 1465 sp->se_nspace = 0; 1466 1467 /* 1468 * fork(), not vfork() -- we can't afford to block. 1469 */ 1470 if ((pid = fork()) == -1) { 1471 emergency("can't fork for getty on port %s: %m", sp->se_device); 1472 return -1; 1473 } 1474 1475 if (pid) 1476 return pid; 1477 1478 if (too_quick) { 1479 warning("getty repeating too quickly on port %s, sleeping %d secs", 1480 sp->se_device, GETTY_SLEEP); 1481 sleep((unsigned) GETTY_SLEEP); 1482 } 1483 1484 if (sp->se_window) { 1485 start_window_system(sp); 1486 sleep(WINDOW_WAIT); 1487 } 1488 1489 sigemptyset(&mask); 1490 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1491 1492 #ifdef LOGIN_CAP 1493 setprocresources(RESOURCE_GETTY); 1494 #endif 1495 if (sp->se_type) { 1496 /* Don't use malloc after fork */ 1497 strcpy(term, "TERM="); 1498 strlcat(term, sp->se_type, sizeof(term)); 1499 env[0] = term; 1500 env[1] = 0; 1501 } else 1502 env[0] = 0; 1503 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1504 stall("can't exec getty '%s' for port %s: %m", 1505 sp->se_getty_argv[0], sp->se_device); 1506 _exit(1); 1507 } 1508 1509 /* 1510 * Collect exit status for a child. 1511 * If an exiting login, start a new login running. 1512 */ 1513 static void 1514 collect_child(pid_t pid) 1515 { 1516 session_t *sp, *sprev, *snext; 1517 1518 if (! sessions) 1519 return; 1520 1521 if (! (sp = find_session(pid))) 1522 return; 1523 1524 del_session(sp); 1525 sp->se_process = 0; 1526 1527 if (sp->se_flags & SE_SHUTDOWN) { 1528 if ((sprev = sp->se_prev) != NULL) 1529 sprev->se_next = sp->se_next; 1530 else 1531 sessions = sp->se_next; 1532 if ((snext = sp->se_next) != NULL) 1533 snext->se_prev = sp->se_prev; 1534 free_session(sp); 1535 return; 1536 } 1537 1538 if ((pid = start_getty(sp)) == -1) { 1539 /* serious trouble */ 1540 requested_transition = clean_ttys; 1541 return; 1542 } 1543 1544 sp->se_process = pid; 1545 sp->se_started = time((time_t *) 0); 1546 add_session(sp); 1547 } 1548 1549 /* 1550 * Catch a signal and request a state transition. 1551 */ 1552 static void 1553 transition_handler(int sig) 1554 { 1555 1556 switch (sig) { 1557 case SIGHUP: 1558 if (current_state == read_ttys || current_state == multi_user || 1559 current_state == clean_ttys || current_state == catatonia) 1560 requested_transition = clean_ttys; 1561 break; 1562 case SIGWINCH: 1563 case SIGUSR2: 1564 howto = sig == SIGUSR2 ? RB_POWEROFF : RB_POWERCYCLE; 1565 case SIGUSR1: 1566 howto |= RB_HALT; 1567 case SIGINT: 1568 Reboot = TRUE; 1569 case SIGTERM: 1570 if (current_state == read_ttys || current_state == multi_user || 1571 current_state == clean_ttys || current_state == catatonia) 1572 requested_transition = death; 1573 else 1574 requested_transition = death_single; 1575 break; 1576 case SIGTSTP: 1577 if (current_state == runcom || current_state == read_ttys || 1578 current_state == clean_ttys || 1579 current_state == multi_user || current_state == catatonia) 1580 requested_transition = catatonia; 1581 break; 1582 case SIGEMT: 1583 requested_transition = reroot; 1584 break; 1585 default: 1586 requested_transition = 0; 1587 break; 1588 } 1589 } 1590 1591 /* 1592 * Take the system multiuser. 1593 */ 1594 static state_func_t 1595 multi_user(void) 1596 { 1597 pid_t pid; 1598 session_t *sp; 1599 1600 requested_transition = 0; 1601 1602 /* 1603 * If the administrator has not set the security level to -1 1604 * to indicate that the kernel should not run multiuser in secure 1605 * mode, and the run script has not set a higher level of security 1606 * than level 1, then put the kernel into secure mode. 1607 */ 1608 if (getsecuritylevel() == 0) 1609 setsecuritylevel(1); 1610 1611 for (sp = sessions; sp; sp = sp->se_next) { 1612 if (sp->se_process) 1613 continue; 1614 if ((pid = start_getty(sp)) == -1) { 1615 /* serious trouble */ 1616 requested_transition = clean_ttys; 1617 break; 1618 } 1619 sp->se_process = pid; 1620 sp->se_started = time((time_t *) 0); 1621 add_session(sp); 1622 } 1623 1624 while (!requested_transition) 1625 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1626 collect_child(pid); 1627 1628 return (state_func_t) requested_transition; 1629 } 1630 1631 /* 1632 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1633 */ 1634 static state_func_t 1635 clean_ttys(void) 1636 { 1637 session_t *sp, *sprev; 1638 struct ttyent *typ; 1639 int devlen; 1640 char *old_getty, *old_window, *old_type; 1641 1642 /* 1643 * mark all sessions for death, (!SE_PRESENT) 1644 * as we find or create new ones they'll be marked as keepers, 1645 * we'll later nuke all the ones not found in /etc/ttys 1646 */ 1647 for (sp = sessions; sp != NULL; sp = sp->se_next) 1648 sp->se_flags &= ~SE_PRESENT; 1649 1650 devlen = sizeof(_PATH_DEV) - 1; 1651 while ((typ = getttyent()) != NULL) { 1652 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1653 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1654 break; 1655 1656 if (sp) { 1657 /* we want this one to live */ 1658 sp->se_flags |= SE_PRESENT; 1659 if ((typ->ty_status & TTY_ON) == 0 || 1660 typ->ty_getty == 0) { 1661 sp->se_flags |= SE_SHUTDOWN; 1662 kill(sp->se_process, SIGHUP); 1663 continue; 1664 } 1665 sp->se_flags &= ~SE_SHUTDOWN; 1666 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1667 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1668 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1669 if (setupargv(sp, typ) == 0) { 1670 warning("can't parse getty for port %s", 1671 sp->se_device); 1672 sp->se_flags |= SE_SHUTDOWN; 1673 kill(sp->se_process, SIGHUP); 1674 } 1675 else if ( !old_getty 1676 || (!old_type && sp->se_type) 1677 || (old_type && !sp->se_type) 1678 || (!old_window && sp->se_window) 1679 || (old_window && !sp->se_window) 1680 || (strcmp(old_getty, sp->se_getty) != 0) 1681 || (old_window && strcmp(old_window, sp->se_window) != 0) 1682 || (old_type && strcmp(old_type, sp->se_type) != 0) 1683 ) { 1684 /* Don't set SE_SHUTDOWN here */ 1685 sp->se_nspace = 0; 1686 sp->se_started = 0; 1687 kill(sp->se_process, SIGHUP); 1688 } 1689 if (old_getty) 1690 free(old_getty); 1691 if (old_window) 1692 free(old_window); 1693 if (old_type) 1694 free(old_type); 1695 continue; 1696 } 1697 1698 new_session(sprev, typ); 1699 } 1700 1701 endttyent(); 1702 1703 /* 1704 * sweep through and kill all deleted sessions 1705 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1706 */ 1707 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1708 if ((sp->se_flags & SE_PRESENT) == 0) { 1709 sp->se_flags |= SE_SHUTDOWN; 1710 kill(sp->se_process, SIGHUP); 1711 } 1712 } 1713 1714 return (state_func_t) multi_user; 1715 } 1716 1717 /* 1718 * Block further logins. 1719 */ 1720 static state_func_t 1721 catatonia(void) 1722 { 1723 session_t *sp; 1724 1725 for (sp = sessions; sp; sp = sp->se_next) 1726 sp->se_flags |= SE_SHUTDOWN; 1727 1728 return (state_func_t) multi_user; 1729 } 1730 1731 /* 1732 * Note SIGALRM. 1733 */ 1734 static void 1735 alrm_handler(int sig) 1736 { 1737 1738 (void)sig; 1739 clang = 1; 1740 } 1741 1742 /* 1743 * Bring the system down to single user. 1744 */ 1745 static state_func_t 1746 death(void) 1747 { 1748 int block, blocked; 1749 size_t len; 1750 1751 /* Temporarily block suspend. */ 1752 len = sizeof(blocked); 1753 block = 1; 1754 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1755 &block, sizeof(block)) == -1) 1756 blocked = 0; 1757 1758 /* 1759 * Also revoke the TTY here. Because runshutdown() may reopen 1760 * the TTY whose getty we're killing here, there is no guarantee 1761 * runshutdown() will perform the initial open() call, causing 1762 * the terminal attributes to be misconfigured. 1763 */ 1764 revoke_ttys(); 1765 1766 /* Try to run the rc.shutdown script within a period of time */ 1767 runshutdown(); 1768 1769 /* Unblock suspend if we blocked it. */ 1770 if (!blocked) 1771 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1772 &blocked, sizeof(blocked)); 1773 1774 return (state_func_t) death_single; 1775 } 1776 1777 /* 1778 * Do what is necessary to reinitialize single user mode or reboot 1779 * from an incomplete state. 1780 */ 1781 static state_func_t 1782 death_single(void) 1783 { 1784 int i; 1785 pid_t pid; 1786 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1787 1788 revoke(_PATH_CONSOLE); 1789 1790 for (i = 0; i < 2; ++i) { 1791 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1792 return (state_func_t) single_user; 1793 1794 clang = 0; 1795 alarm(DEATH_WATCH); 1796 do 1797 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1798 collect_child(pid); 1799 while (clang == 0 && errno != ECHILD); 1800 1801 if (errno == ECHILD) 1802 return (state_func_t) single_user; 1803 } 1804 1805 warning("some processes would not die; ps axl advised"); 1806 1807 return (state_func_t) single_user; 1808 } 1809 1810 static void 1811 revoke_ttys(void) 1812 { 1813 session_t *sp; 1814 1815 for (sp = sessions; sp; sp = sp->se_next) { 1816 sp->se_flags |= SE_SHUTDOWN; 1817 kill(sp->se_process, SIGHUP); 1818 revoke(sp->se_device); 1819 } 1820 } 1821 1822 /* 1823 * Run the system shutdown script. 1824 * 1825 * Exit codes: XXX I should document more 1826 * -2 shutdown script terminated abnormally 1827 * -1 fatal error - can't run script 1828 * 0 good. 1829 * >0 some error (exit code) 1830 */ 1831 static int 1832 runshutdown(void) 1833 { 1834 pid_t pid, wpid; 1835 int status; 1836 int shutdowntimeout; 1837 size_t len; 1838 char *argv[4]; 1839 const char *shell; 1840 struct sigaction sa; 1841 struct stat sb; 1842 1843 /* 1844 * rc.shutdown is optional, so to prevent any unnecessary 1845 * complaints from the shell we simply don't run it if the 1846 * file does not exist. If the stat() here fails for other 1847 * reasons, we'll let the shell complain. 1848 */ 1849 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1850 return 0; 1851 1852 shell = get_shell(); 1853 1854 if ((pid = fork()) == 0) { 1855 sigemptyset(&sa.sa_mask); 1856 sa.sa_flags = 0; 1857 sa.sa_handler = SIG_IGN; 1858 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1859 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1860 1861 open_console(); 1862 1863 char _sh[] = "sh"; 1864 char _reboot[] = "reboot"; 1865 char _single[] = "single"; 1866 char _path_rundown[] = _PATH_RUNDOWN; 1867 1868 argv[0] = _sh; 1869 argv[1] = _path_rundown; 1870 argv[2] = Reboot ? _reboot : _single; 1871 argv[3] = 0; 1872 1873 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1874 1875 #ifdef LOGIN_CAP 1876 setprocresources(RESOURCE_RC); 1877 #endif 1878 execv(shell, argv); 1879 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1880 _exit(1); /* force single user mode */ 1881 } 1882 1883 if (pid == -1) { 1884 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1885 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1886 continue; 1887 sleep(STALL_TIMEOUT); 1888 return -1; 1889 } 1890 1891 len = sizeof(shutdowntimeout); 1892 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1893 NULL, 0) == -1 || shutdowntimeout < 2) 1894 shutdowntimeout = DEATH_SCRIPT; 1895 alarm(shutdowntimeout); 1896 clang = 0; 1897 /* 1898 * Copied from single_user(). This is a bit paranoid. 1899 * Use the same ALRM handler. 1900 */ 1901 do { 1902 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1903 collect_child(wpid); 1904 if (clang == 1) { 1905 /* we were waiting for the sub-shell */ 1906 kill(wpid, SIGTERM); 1907 warning("timeout expired for %s on %s: %m; going to " 1908 "single user mode", shell, _PATH_RUNDOWN); 1909 return -1; 1910 } 1911 if (wpid == -1) { 1912 if (errno == EINTR) 1913 continue; 1914 warning("wait for %s on %s failed: %m; going to " 1915 "single user mode", shell, _PATH_RUNDOWN); 1916 return -1; 1917 } 1918 if (wpid == pid && WIFSTOPPED(status)) { 1919 warning("init: %s on %s stopped, restarting\n", 1920 shell, _PATH_RUNDOWN); 1921 kill(pid, SIGCONT); 1922 wpid = -1; 1923 } 1924 } while (wpid != pid && !clang); 1925 1926 /* Turn off the alarm */ 1927 alarm(0); 1928 1929 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1930 requested_transition == catatonia) { 1931 /* 1932 * /etc/rc.shutdown executed /sbin/reboot; 1933 * wait for the end quietly 1934 */ 1935 sigset_t s; 1936 1937 sigfillset(&s); 1938 for (;;) 1939 sigsuspend(&s); 1940 } 1941 1942 if (!WIFEXITED(status)) { 1943 warning("%s on %s terminated abnormally, going to " 1944 "single user mode", shell, _PATH_RUNDOWN); 1945 return -2; 1946 } 1947 1948 if ((status = WEXITSTATUS(status)) != 0) 1949 warning("%s returned status %d", _PATH_RUNDOWN, status); 1950 1951 return status; 1952 } 1953 1954 static char * 1955 strk(char *p) 1956 { 1957 static char *t; 1958 char *q; 1959 int c; 1960 1961 if (p) 1962 t = p; 1963 if (!t) 1964 return 0; 1965 1966 c = *t; 1967 while (c == ' ' || c == '\t' ) 1968 c = *++t; 1969 if (!c) { 1970 t = 0; 1971 return 0; 1972 } 1973 q = t; 1974 if (c == '\'') { 1975 c = *++t; 1976 q = t; 1977 while (c && c != '\'') 1978 c = *++t; 1979 if (!c) /* unterminated string */ 1980 q = t = 0; 1981 else 1982 *t++ = 0; 1983 } else { 1984 while (c && c != ' ' && c != '\t' ) 1985 c = *++t; 1986 *t++ = 0; 1987 if (!c) 1988 t = 0; 1989 } 1990 return q; 1991 } 1992 1993 #ifdef LOGIN_CAP 1994 static void 1995 setprocresources(const char *cname) 1996 { 1997 login_cap_t *lc; 1998 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 1999 setusercontext(lc, (struct passwd*)NULL, 0, 2000 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2001 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2002 login_close(lc); 2003 } 2004 } 2005 #endif 2006