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 #define SE_IFEXISTS 0x4 /* session defined as "onifexists" */ 160 #define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */ 161 int se_nspace; /* spacing count */ 162 char *se_device; /* filename of port */ 163 char *se_getty; /* what to run on that port */ 164 char *se_getty_argv_space; /* pre-parsed argument array space */ 165 char **se_getty_argv; /* pre-parsed argument array */ 166 char *se_window; /* window system (started only once) */ 167 char *se_window_argv_space; /* pre-parsed argument array space */ 168 char **se_window_argv; /* pre-parsed argument array */ 169 char *se_type; /* default terminal type */ 170 struct init_session *se_prev; 171 struct init_session *se_next; 172 } session_t; 173 174 static void free_session(session_t *); 175 static session_t *new_session(session_t *, struct ttyent *); 176 static session_t *sessions; 177 178 static char **construct_argv(char *); 179 static void start_window_system(session_t *); 180 static void collect_child(pid_t); 181 static pid_t start_getty(session_t *); 182 static void transition_handler(int); 183 static void alrm_handler(int); 184 static void setsecuritylevel(int); 185 static int getsecuritylevel(void); 186 static int setupargv(session_t *, struct ttyent *); 187 #ifdef LOGIN_CAP 188 static void setprocresources(const char *); 189 #endif 190 static int clang; 191 192 static int start_session_db(void); 193 static void add_session(session_t *); 194 static void del_session(session_t *); 195 static session_t *find_session(pid_t); 196 static DB *session_db; 197 198 /* 199 * The mother of all processes. 200 */ 201 int 202 main(int argc, char *argv[]) 203 { 204 state_t initial_transition = runcom; 205 char kenv_value[PATH_MAX]; 206 int c, error; 207 struct sigaction sa; 208 sigset_t mask; 209 210 /* Dispose of random users. */ 211 if (getuid() != 0) 212 errx(1, "%s", strerror(EPERM)); 213 214 /* System V users like to reexec init. */ 215 if (getpid() != 1) { 216 #ifdef COMPAT_SYSV_INIT 217 /* So give them what they want */ 218 if (argc > 1) { 219 if (strlen(argv[1]) == 1) { 220 char runlevel = *argv[1]; 221 int sig; 222 223 switch (runlevel) { 224 case '0': /* halt + poweroff */ 225 sig = SIGUSR2; 226 break; 227 case '1': /* single-user */ 228 sig = SIGTERM; 229 break; 230 case '6': /* reboot */ 231 sig = SIGINT; 232 break; 233 case 'c': /* block further logins */ 234 sig = SIGTSTP; 235 break; 236 case 'q': /* rescan /etc/ttys */ 237 sig = SIGHUP; 238 break; 239 case 'r': /* remount root */ 240 sig = SIGEMT; 241 break; 242 default: 243 goto invalid; 244 } 245 kill(1, sig); 246 _exit(0); 247 } else 248 invalid: 249 errx(1, "invalid run-level ``%s''", argv[1]); 250 } else 251 #endif 252 errx(1, "already running"); 253 } 254 255 init_path_argv0 = strdup(argv[0]); 256 if (init_path_argv0 == NULL) 257 err(1, "strdup"); 258 259 /* 260 * Note that this does NOT open a file... 261 * Does 'init' deserve its own facility number? 262 */ 263 openlog("init", LOG_CONS, LOG_AUTH); 264 265 /* 266 * Create an initial session. 267 */ 268 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 269 warning("initial setsid() failed: %m"); 270 271 /* 272 * Establish an initial user so that programs running 273 * single user do not freak out and die (like passwd). 274 */ 275 if (setlogin("root") < 0) 276 warning("setlogin() failed: %m"); 277 278 /* 279 * This code assumes that we always get arguments through flags, 280 * never through bits set in some random machine register. 281 */ 282 while ((c = getopt(argc, argv, "dsfr")) != -1) 283 switch (c) { 284 case 'd': 285 devfs = 1; 286 break; 287 case 's': 288 initial_transition = single_user; 289 break; 290 case 'f': 291 runcom_mode = FASTBOOT; 292 break; 293 case 'r': 294 initial_transition = reroot_phase_two; 295 break; 296 default: 297 warning("unrecognized flag '-%c'", c); 298 break; 299 } 300 301 if (optind != argc) 302 warning("ignoring excess arguments"); 303 304 /* 305 * We catch or block signals rather than ignore them, 306 * so that they get reset on exec. 307 */ 308 handle(badsys, SIGSYS, 0); 309 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 310 SIGXFSZ, 0); 311 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 312 SIGUSR1, SIGUSR2, SIGWINCH, 0); 313 handle(alrm_handler, SIGALRM, 0); 314 sigfillset(&mask); 315 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 316 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 317 SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0); 318 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 319 sigemptyset(&sa.sa_mask); 320 sa.sa_flags = 0; 321 sa.sa_handler = SIG_IGN; 322 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 323 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 324 325 /* 326 * Paranoia. 327 */ 328 close(0); 329 close(1); 330 close(2); 331 332 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 333 state_func_t next_transition; 334 335 if ((next_transition = run_script(kenv_value)) != NULL) 336 initial_transition = (state_t) next_transition; 337 } 338 339 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 340 if (chdir(kenv_value) != 0 || chroot(".") != 0) 341 warning("Can't chroot to %s: %m", kenv_value); 342 } 343 344 /* 345 * Additional check if devfs needs to be mounted: 346 * If "/" and "/dev" have the same device number, 347 * then it hasn't been mounted yet. 348 */ 349 if (!devfs) { 350 struct stat stst; 351 dev_t root_devno; 352 353 stat("/", &stst); 354 root_devno = stst.st_dev; 355 if (stat("/dev", &stst) != 0) 356 warning("Can't stat /dev: %m"); 357 else if (stst.st_dev == root_devno) 358 devfs++; 359 } 360 361 if (devfs) { 362 struct iovec iov[4]; 363 char *s; 364 int i; 365 366 char _fstype[] = "fstype"; 367 char _devfs[] = "devfs"; 368 char _fspath[] = "fspath"; 369 char _path_dev[]= _PATH_DEV; 370 371 iov[0].iov_base = _fstype; 372 iov[0].iov_len = sizeof(_fstype); 373 iov[1].iov_base = _devfs; 374 iov[1].iov_len = sizeof(_devfs); 375 iov[2].iov_base = _fspath; 376 iov[2].iov_len = sizeof(_fspath); 377 /* 378 * Try to avoid the trailing slash in _PATH_DEV. 379 * Be *very* defensive. 380 */ 381 s = strdup(_PATH_DEV); 382 if (s != NULL) { 383 i = strlen(s); 384 if (i > 0 && s[i - 1] == '/') 385 s[i - 1] = '\0'; 386 iov[3].iov_base = s; 387 iov[3].iov_len = strlen(s) + 1; 388 } else { 389 iov[3].iov_base = _path_dev; 390 iov[3].iov_len = sizeof(_path_dev); 391 } 392 nmount(iov, 4, 0); 393 if (s != NULL) 394 free(s); 395 } 396 397 if (initial_transition != reroot_phase_two) { 398 /* 399 * Unmount reroot leftovers. This runs after init(8) 400 * gets reexecuted after reroot_phase_two() is done. 401 */ 402 error = unmount(_PATH_REROOT, MNT_FORCE); 403 if (error != 0 && errno != EINVAL) 404 warning("Cannot unmount %s: %m", _PATH_REROOT); 405 } 406 407 /* 408 * Start the state machine. 409 */ 410 transition(initial_transition); 411 412 /* 413 * Should never reach here. 414 */ 415 return 1; 416 } 417 418 /* 419 * Associate a function with a signal handler. 420 */ 421 static void 422 handle(sig_t handler, ...) 423 { 424 int sig; 425 struct sigaction sa; 426 sigset_t mask_everything; 427 va_list ap; 428 va_start(ap, handler); 429 430 sa.sa_handler = handler; 431 sigfillset(&mask_everything); 432 433 while ((sig = va_arg(ap, int)) != 0) { 434 sa.sa_mask = mask_everything; 435 /* XXX SA_RESTART? */ 436 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 437 sigaction(sig, &sa, (struct sigaction *) 0); 438 } 439 va_end(ap); 440 } 441 442 /* 443 * Delete a set of signals from a mask. 444 */ 445 static void 446 delset(sigset_t *maskp, ...) 447 { 448 int sig; 449 va_list ap; 450 va_start(ap, maskp); 451 452 while ((sig = va_arg(ap, int)) != 0) 453 sigdelset(maskp, sig); 454 va_end(ap); 455 } 456 457 /* 458 * Log a message and sleep for a while (to give someone an opportunity 459 * to read it and to save log or hardcopy output if the problem is chronic). 460 * NB: should send a message to the session logger to avoid blocking. 461 */ 462 static void 463 stall(const char *message, ...) 464 { 465 va_list ap; 466 va_start(ap, message); 467 468 vsyslog(LOG_ALERT, message, ap); 469 va_end(ap); 470 sleep(STALL_TIMEOUT); 471 } 472 473 /* 474 * Like stall(), but doesn't sleep. 475 * If cpp had variadic macros, the two functions could be #defines for another. 476 * NB: should send a message to the session logger to avoid blocking. 477 */ 478 static void 479 warning(const char *message, ...) 480 { 481 va_list ap; 482 va_start(ap, message); 483 484 vsyslog(LOG_ALERT, message, ap); 485 va_end(ap); 486 } 487 488 /* 489 * Log an emergency message. 490 * NB: should send a message to the session logger to avoid blocking. 491 */ 492 static void 493 emergency(const char *message, ...) 494 { 495 va_list ap; 496 va_start(ap, message); 497 498 vsyslog(LOG_EMERG, message, ap); 499 va_end(ap); 500 } 501 502 /* 503 * Catch a SIGSYS signal. 504 * 505 * These may arise if a system does not support sysctl. 506 * We tolerate up to 25 of these, then throw in the towel. 507 */ 508 static void 509 badsys(int sig) 510 { 511 static int badcount = 0; 512 513 if (badcount++ < 25) 514 return; 515 disaster(sig); 516 } 517 518 /* 519 * Catch an unexpected signal. 520 */ 521 static void 522 disaster(int sig) 523 { 524 525 emergency("fatal signal: %s", 526 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 527 528 sleep(STALL_TIMEOUT); 529 _exit(sig); /* reboot */ 530 } 531 532 /* 533 * Get the security level of the kernel. 534 */ 535 static int 536 getsecuritylevel(void) 537 { 538 #ifdef KERN_SECURELVL 539 int name[2], curlevel; 540 size_t len; 541 542 name[0] = CTL_KERN; 543 name[1] = KERN_SECURELVL; 544 len = sizeof curlevel; 545 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 546 emergency("cannot get kernel security level: %s", 547 strerror(errno)); 548 return (-1); 549 } 550 return (curlevel); 551 #else 552 return (-1); 553 #endif 554 } 555 556 /* 557 * Set the security level of the kernel. 558 */ 559 static void 560 setsecuritylevel(int newlevel) 561 { 562 #ifdef KERN_SECURELVL 563 int name[2], curlevel; 564 565 curlevel = getsecuritylevel(); 566 if (newlevel == curlevel) 567 return; 568 name[0] = CTL_KERN; 569 name[1] = KERN_SECURELVL; 570 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 571 emergency( 572 "cannot change kernel security level from %d to %d: %s", 573 curlevel, newlevel, strerror(errno)); 574 return; 575 } 576 #ifdef SECURE 577 warning("kernel security level changed from %d to %d", 578 curlevel, newlevel); 579 #endif 580 #endif 581 } 582 583 /* 584 * Change states in the finite state machine. 585 * The initial state is passed as an argument. 586 */ 587 static void 588 transition(state_t s) 589 { 590 591 current_state = s; 592 for (;;) 593 current_state = (state_t) (*current_state)(); 594 } 595 596 /* 597 * Start a session and allocate a controlling terminal. 598 * Only called by children of init after forking. 599 */ 600 static void 601 open_console(void) 602 { 603 int fd; 604 605 /* 606 * Try to open /dev/console. Open the device with O_NONBLOCK to 607 * prevent potential blocking on a carrier. 608 */ 609 revoke(_PATH_CONSOLE); 610 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 611 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 612 if (login_tty(fd) == 0) 613 return; 614 close(fd); 615 } 616 617 /* No luck. Log output to file if possible. */ 618 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 619 stall("cannot open null device."); 620 _exit(1); 621 } 622 if (fd != STDIN_FILENO) { 623 dup2(fd, STDIN_FILENO); 624 close(fd); 625 } 626 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 627 if (fd == -1) 628 dup2(STDIN_FILENO, STDOUT_FILENO); 629 else if (fd != STDOUT_FILENO) { 630 dup2(fd, STDOUT_FILENO); 631 close(fd); 632 } 633 dup2(STDOUT_FILENO, STDERR_FILENO); 634 } 635 636 static const char * 637 get_shell(void) 638 { 639 static char kenv_value[PATH_MAX]; 640 641 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 642 return kenv_value; 643 else 644 return _PATH_BSHELL; 645 } 646 647 static void 648 write_stderr(const char *message) 649 { 650 651 write(STDERR_FILENO, message, strlen(message)); 652 } 653 654 static int 655 read_file(const char *path, void **bufp, size_t *bufsizep) 656 { 657 struct stat sb; 658 size_t bufsize; 659 void *buf; 660 ssize_t nbytes; 661 int error, fd; 662 663 fd = open(path, O_RDONLY); 664 if (fd < 0) { 665 emergency("%s: %s", path, strerror(errno)); 666 return (-1); 667 } 668 669 error = fstat(fd, &sb); 670 if (error != 0) { 671 emergency("fstat: %s", strerror(errno)); 672 close(fd); 673 return (error); 674 } 675 676 bufsize = sb.st_size; 677 buf = malloc(bufsize); 678 if (buf == NULL) { 679 emergency("malloc: %s", strerror(errno)); 680 close(fd); 681 return (error); 682 } 683 684 nbytes = read(fd, buf, bufsize); 685 if (nbytes != (ssize_t)bufsize) { 686 emergency("read: %s", strerror(errno)); 687 close(fd); 688 free(buf); 689 return (error); 690 } 691 692 error = close(fd); 693 if (error != 0) { 694 emergency("close: %s", strerror(errno)); 695 free(buf); 696 return (error); 697 } 698 699 *bufp = buf; 700 *bufsizep = bufsize; 701 702 return (0); 703 } 704 705 static int 706 create_file(const char *path, const void *buf, size_t bufsize) 707 { 708 ssize_t nbytes; 709 int error, fd; 710 711 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 712 if (fd < 0) { 713 emergency("%s: %s", path, strerror(errno)); 714 return (-1); 715 } 716 717 nbytes = write(fd, buf, bufsize); 718 if (nbytes != (ssize_t)bufsize) { 719 emergency("write: %s", strerror(errno)); 720 close(fd); 721 return (-1); 722 } 723 724 error = close(fd); 725 if (error != 0) { 726 emergency("close: %s", strerror(errno)); 727 return (-1); 728 } 729 730 return (0); 731 } 732 733 static int 734 mount_tmpfs(const char *fspath) 735 { 736 struct iovec *iov; 737 char errmsg[255]; 738 int error, iovlen; 739 740 iov = NULL; 741 iovlen = 0; 742 memset(errmsg, 0, sizeof(errmsg)); 743 build_iovec(&iov, &iovlen, "fstype", 744 __DECONST(void *, "tmpfs"), (size_t)-1); 745 build_iovec(&iov, &iovlen, "fspath", 746 __DECONST(void *, fspath), (size_t)-1); 747 build_iovec(&iov, &iovlen, "errmsg", 748 errmsg, sizeof(errmsg)); 749 750 error = nmount(iov, iovlen, 0); 751 if (error != 0) { 752 if (*errmsg != '\0') { 753 emergency("cannot mount tmpfs on %s: %s: %s", 754 fspath, errmsg, strerror(errno)); 755 } else { 756 emergency("cannot mount tmpfs on %s: %s", 757 fspath, strerror(errno)); 758 } 759 return (error); 760 } 761 return (0); 762 } 763 764 static state_func_t 765 reroot(void) 766 { 767 void *buf; 768 size_t bufsize; 769 int error; 770 771 buf = NULL; 772 bufsize = 0; 773 774 revoke_ttys(); 775 runshutdown(); 776 777 /* 778 * Make sure nobody can interfere with our scheme. 779 * Ignore ESRCH, which can apparently happen when 780 * there are no processes to kill. 781 */ 782 error = kill(-1, SIGKILL); 783 if (error != 0 && errno != ESRCH) { 784 emergency("kill(2) failed: %s", strerror(errno)); 785 goto out; 786 } 787 788 /* 789 * Copy the init binary into tmpfs, so that we can unmount 790 * the old rootfs without committing suicide. 791 */ 792 error = read_file(init_path_argv0, &buf, &bufsize); 793 if (error != 0) 794 goto out; 795 error = mount_tmpfs(_PATH_REROOT); 796 if (error != 0) 797 goto out; 798 error = create_file(_PATH_REROOT_INIT, buf, bufsize); 799 if (error != 0) 800 goto out; 801 802 /* 803 * Execute the temporary init. 804 */ 805 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); 806 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno)); 807 808 out: 809 emergency("reroot failed; going to single user mode"); 810 free(buf); 811 return (state_func_t) single_user; 812 } 813 814 static state_func_t 815 reroot_phase_two(void) 816 { 817 char init_path[PATH_MAX], *path, *path_component; 818 size_t init_path_len; 819 int nbytes, error; 820 821 /* 822 * Ask the kernel to mount the new rootfs. 823 */ 824 error = reboot(RB_REROOT); 825 if (error != 0) { 826 emergency("RB_REBOOT failed: %s", strerror(errno)); 827 goto out; 828 } 829 830 /* 831 * Figure out where the destination init(8) binary is. Note that 832 * the path could be different than what we've started with. Use 833 * the value from kenv, if set, or the one from sysctl otherwise. 834 * The latter defaults to a hardcoded value, but can be overridden 835 * by a build time option. 836 */ 837 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 838 if (nbytes <= 0) { 839 init_path_len = sizeof(init_path); 840 error = sysctlbyname("kern.init_path", 841 init_path, &init_path_len, NULL, 0); 842 if (error != 0) { 843 emergency("failed to retrieve kern.init_path: %s", 844 strerror(errno)); 845 goto out; 846 } 847 } 848 849 /* 850 * Repeat the init search logic from sys/kern/init_path.c 851 */ 852 path_component = init_path; 853 while ((path = strsep(&path_component, ":")) != NULL) { 854 /* 855 * Execute init(8) from the new rootfs. 856 */ 857 execl(path, path, NULL); 858 } 859 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 860 861 out: 862 emergency("reroot failed; going to single user mode"); 863 return (state_func_t) single_user; 864 } 865 866 /* 867 * Bring the system up single user. 868 */ 869 static state_func_t 870 single_user(void) 871 { 872 pid_t pid, wpid; 873 int status; 874 sigset_t mask; 875 const char *shell; 876 char *argv[2]; 877 struct timeval tv, tn; 878 #ifdef SECURE 879 struct ttyent *typ; 880 struct passwd *pp; 881 static const char banner[] = 882 "Enter root password, or ^D to go multi-user\n"; 883 char *clear, *password; 884 #endif 885 #ifdef DEBUGSHELL 886 char altshell[128]; 887 #endif 888 889 if (Reboot) { 890 /* Instead of going single user, let's reboot the machine */ 891 sync(); 892 if (reboot(howto) == -1) { 893 emergency("reboot(%#x) failed, %s", howto, 894 strerror(errno)); 895 _exit(1); /* panic and reboot */ 896 } 897 warning("reboot(%#x) returned", howto); 898 _exit(0); /* panic as well */ 899 } 900 901 shell = get_shell(); 902 903 if ((pid = fork()) == 0) { 904 /* 905 * Start the single user session. 906 */ 907 open_console(); 908 909 #ifdef SECURE 910 /* 911 * Check the root password. 912 * We don't care if the console is 'on' by default; 913 * it's the only tty that can be 'off' and 'secure'. 914 */ 915 typ = getttynam("console"); 916 pp = getpwnam("root"); 917 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 918 pp && *pp->pw_passwd) { 919 write_stderr(banner); 920 for (;;) { 921 clear = getpass("Password:"); 922 if (clear == NULL || *clear == '\0') 923 _exit(0); 924 password = crypt(clear, pp->pw_passwd); 925 bzero(clear, _PASSWORD_LEN); 926 if (password != NULL && 927 strcmp(password, pp->pw_passwd) == 0) 928 break; 929 warning("single-user login failed\n"); 930 } 931 } 932 endttyent(); 933 endpwent(); 934 #endif /* SECURE */ 935 936 #ifdef DEBUGSHELL 937 { 938 char *cp = altshell; 939 int num; 940 941 #define SHREQUEST "Enter full pathname of shell or RETURN for " 942 write_stderr(SHREQUEST); 943 write_stderr(shell); 944 write_stderr(": "); 945 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 946 num != 0 && *cp != '\n' && cp < &altshell[127]) 947 cp++; 948 *cp = '\0'; 949 if (altshell[0] != '\0') 950 shell = altshell; 951 } 952 #endif /* DEBUGSHELL */ 953 954 /* 955 * Unblock signals. 956 * We catch all the interesting ones, 957 * and those are reset to SIG_DFL on exec. 958 */ 959 sigemptyset(&mask); 960 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 961 962 /* 963 * Fire off a shell. 964 * If the default one doesn't work, try the Bourne shell. 965 */ 966 967 char name[] = "-sh"; 968 969 argv[0] = name; 970 argv[1] = 0; 971 execv(shell, argv); 972 emergency("can't exec %s for single user: %m", shell); 973 execv(_PATH_BSHELL, argv); 974 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 975 sleep(STALL_TIMEOUT); 976 _exit(1); 977 } 978 979 if (pid == -1) { 980 /* 981 * We are seriously hosed. Do our best. 982 */ 983 emergency("can't fork single-user shell, trying again"); 984 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 985 continue; 986 return (state_func_t) single_user; 987 } 988 989 requested_transition = 0; 990 do { 991 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 992 collect_child(wpid); 993 if (wpid == -1) { 994 if (errno == EINTR) 995 continue; 996 warning("wait for single-user shell failed: %m; restarting"); 997 return (state_func_t) single_user; 998 } 999 if (wpid == pid && WIFSTOPPED(status)) { 1000 warning("init: shell stopped, restarting\n"); 1001 kill(pid, SIGCONT); 1002 wpid = -1; 1003 } 1004 } while (wpid != pid && !requested_transition); 1005 1006 if (requested_transition) 1007 return (state_func_t) requested_transition; 1008 1009 if (!WIFEXITED(status)) { 1010 if (WTERMSIG(status) == SIGKILL) { 1011 /* 1012 * reboot(8) killed shell? 1013 */ 1014 warning("single user shell terminated."); 1015 gettimeofday(&tv, NULL); 1016 tn = tv; 1017 tv.tv_sec += STALL_TIMEOUT; 1018 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == 1019 tn.tv_sec && tv.tv_usec > tn.tv_usec)) { 1020 sleep(1); 1021 gettimeofday(&tn, NULL); 1022 } 1023 _exit(0); 1024 } else { 1025 warning("single user shell terminated, restarting"); 1026 return (state_func_t) single_user; 1027 } 1028 } 1029 1030 runcom_mode = FASTBOOT; 1031 return (state_func_t) runcom; 1032 } 1033 1034 /* 1035 * Run the system startup script. 1036 */ 1037 static state_func_t 1038 runcom(void) 1039 { 1040 state_func_t next_transition; 1041 1042 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL) 1043 return next_transition; 1044 1045 runcom_mode = AUTOBOOT; /* the default */ 1046 return (state_func_t) read_ttys; 1047 } 1048 1049 /* 1050 * Run a shell script. 1051 * Returns 0 on success, otherwise the next transition to enter: 1052 * - single_user if fork/execv/waitpid failed, or if the script 1053 * terminated with a signal or exit code != 0. 1054 * - death_single if a SIGTERM was delivered to init(8). 1055 */ 1056 static state_func_t 1057 run_script(const char *script) 1058 { 1059 pid_t pid, wpid; 1060 int status; 1061 char *argv[4]; 1062 const char *shell; 1063 struct sigaction sa; 1064 1065 shell = get_shell(); 1066 1067 if ((pid = fork()) == 0) { 1068 sigemptyset(&sa.sa_mask); 1069 sa.sa_flags = 0; 1070 sa.sa_handler = SIG_IGN; 1071 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1072 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1073 1074 open_console(); 1075 1076 char _sh[] = "sh"; 1077 char _autoboot[] = "autoboot"; 1078 1079 argv[0] = _sh; 1080 argv[1] = __DECONST(char *, script); 1081 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1082 argv[3] = 0; 1083 1084 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1085 1086 #ifdef LOGIN_CAP 1087 setprocresources(RESOURCE_RC); 1088 #endif 1089 execv(shell, argv); 1090 stall("can't exec %s for %s: %m", shell, script); 1091 _exit(1); /* force single user mode */ 1092 } 1093 1094 if (pid == -1) { 1095 emergency("can't fork for %s on %s: %m", shell, script); 1096 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1097 continue; 1098 sleep(STALL_TIMEOUT); 1099 return (state_func_t) single_user; 1100 } 1101 1102 /* 1103 * Copied from single_user(). This is a bit paranoid. 1104 */ 1105 requested_transition = 0; 1106 do { 1107 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1108 collect_child(wpid); 1109 if (wpid == -1) { 1110 if (requested_transition == death_single || 1111 requested_transition == reroot) 1112 return (state_func_t) requested_transition; 1113 if (errno == EINTR) 1114 continue; 1115 warning("wait for %s on %s failed: %m; going to " 1116 "single user mode", shell, script); 1117 return (state_func_t) single_user; 1118 } 1119 if (wpid == pid && WIFSTOPPED(status)) { 1120 warning("init: %s on %s stopped, restarting\n", 1121 shell, script); 1122 kill(pid, SIGCONT); 1123 wpid = -1; 1124 } 1125 } while (wpid != pid); 1126 1127 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1128 requested_transition == catatonia) { 1129 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1130 sigset_t s; 1131 1132 sigfillset(&s); 1133 for (;;) 1134 sigsuspend(&s); 1135 } 1136 1137 if (!WIFEXITED(status)) { 1138 warning("%s on %s terminated abnormally, going to single " 1139 "user mode", shell, script); 1140 return (state_func_t) single_user; 1141 } 1142 1143 if (WEXITSTATUS(status)) 1144 return (state_func_t) single_user; 1145 1146 return (state_func_t) 0; 1147 } 1148 1149 /* 1150 * Open the session database. 1151 * 1152 * NB: We could pass in the size here; is it necessary? 1153 */ 1154 static int 1155 start_session_db(void) 1156 { 1157 if (session_db && (*session_db->close)(session_db)) 1158 emergency("session database close: %s", strerror(errno)); 1159 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 1160 emergency("session database open: %s", strerror(errno)); 1161 return (1); 1162 } 1163 return (0); 1164 1165 } 1166 1167 /* 1168 * Add a new login session. 1169 */ 1170 static void 1171 add_session(session_t *sp) 1172 { 1173 DBT key; 1174 DBT data; 1175 1176 key.data = &sp->se_process; 1177 key.size = sizeof sp->se_process; 1178 data.data = &sp; 1179 data.size = sizeof sp; 1180 1181 if ((*session_db->put)(session_db, &key, &data, 0)) 1182 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1183 } 1184 1185 /* 1186 * Delete an old login session. 1187 */ 1188 static void 1189 del_session(session_t *sp) 1190 { 1191 DBT key; 1192 1193 key.data = &sp->se_process; 1194 key.size = sizeof sp->se_process; 1195 1196 if ((*session_db->del)(session_db, &key, 0)) 1197 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1198 } 1199 1200 /* 1201 * Look up a login session by pid. 1202 */ 1203 static session_t * 1204 find_session(pid_t pid) 1205 { 1206 DBT key; 1207 DBT data; 1208 session_t *ret; 1209 1210 key.data = &pid; 1211 key.size = sizeof pid; 1212 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1213 return 0; 1214 bcopy(data.data, (char *)&ret, sizeof(ret)); 1215 return ret; 1216 } 1217 1218 /* 1219 * Construct an argument vector from a command line. 1220 */ 1221 static char ** 1222 construct_argv(char *command) 1223 { 1224 int argc = 0; 1225 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1226 * sizeof (char *)); 1227 1228 if ((argv[argc++] = strk(command)) == NULL) { 1229 free(argv); 1230 return (NULL); 1231 } 1232 while ((argv[argc++] = strk((char *) 0)) != NULL) 1233 continue; 1234 return argv; 1235 } 1236 1237 /* 1238 * Deallocate a session descriptor. 1239 */ 1240 static void 1241 free_session(session_t *sp) 1242 { 1243 free(sp->se_device); 1244 if (sp->se_getty) { 1245 free(sp->se_getty); 1246 free(sp->se_getty_argv_space); 1247 free(sp->se_getty_argv); 1248 } 1249 if (sp->se_window) { 1250 free(sp->se_window); 1251 free(sp->se_window_argv_space); 1252 free(sp->se_window_argv); 1253 } 1254 if (sp->se_type) 1255 free(sp->se_type); 1256 free(sp); 1257 } 1258 1259 /* 1260 * Allocate a new session descriptor. 1261 * Mark it SE_PRESENT. 1262 */ 1263 static session_t * 1264 new_session(session_t *sprev, struct ttyent *typ) 1265 { 1266 session_t *sp; 1267 1268 if ((typ->ty_status & TTY_ON) == 0 || 1269 typ->ty_name == 0 || 1270 typ->ty_getty == 0) 1271 return 0; 1272 1273 sp = (session_t *) calloc(1, sizeof (session_t)); 1274 1275 sp->se_flags |= SE_PRESENT; 1276 1277 if ((typ->ty_status & TTY_IFEXISTS) != 0) 1278 sp->se_flags |= SE_IFEXISTS; 1279 1280 if ((typ->ty_status & TTY_IFCONSOLE) != 0) 1281 sp->se_flags |= SE_IFCONSOLE; 1282 1283 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0) 1284 err(1, "asprintf"); 1285 1286 if (setupargv(sp, typ) == 0) { 1287 free_session(sp); 1288 return (0); 1289 } 1290 1291 sp->se_next = 0; 1292 if (sprev == NULL) { 1293 sessions = sp; 1294 sp->se_prev = 0; 1295 } else { 1296 sprev->se_next = sp; 1297 sp->se_prev = sprev; 1298 } 1299 1300 return sp; 1301 } 1302 1303 /* 1304 * Calculate getty and if useful window argv vectors. 1305 */ 1306 static int 1307 setupargv(session_t *sp, struct ttyent *typ) 1308 { 1309 1310 if (sp->se_getty) { 1311 free(sp->se_getty); 1312 free(sp->se_getty_argv_space); 1313 free(sp->se_getty_argv); 1314 } 1315 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0) 1316 err(1, "asprintf"); 1317 sp->se_getty_argv_space = strdup(sp->se_getty); 1318 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1319 if (sp->se_getty_argv == NULL) { 1320 warning("can't parse getty for port %s", sp->se_device); 1321 free(sp->se_getty); 1322 free(sp->se_getty_argv_space); 1323 sp->se_getty = sp->se_getty_argv_space = 0; 1324 return (0); 1325 } 1326 if (sp->se_window) { 1327 free(sp->se_window); 1328 free(sp->se_window_argv_space); 1329 free(sp->se_window_argv); 1330 } 1331 sp->se_window = sp->se_window_argv_space = 0; 1332 sp->se_window_argv = 0; 1333 if (typ->ty_window) { 1334 sp->se_window = strdup(typ->ty_window); 1335 sp->se_window_argv_space = strdup(sp->se_window); 1336 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1337 if (sp->se_window_argv == NULL) { 1338 warning("can't parse window for port %s", 1339 sp->se_device); 1340 free(sp->se_window_argv_space); 1341 free(sp->se_window); 1342 sp->se_window = sp->se_window_argv_space = 0; 1343 return (0); 1344 } 1345 } 1346 if (sp->se_type) 1347 free(sp->se_type); 1348 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1349 return (1); 1350 } 1351 1352 /* 1353 * Walk the list of ttys and create sessions for each active line. 1354 */ 1355 static state_func_t 1356 read_ttys(void) 1357 { 1358 session_t *sp, *snext; 1359 struct ttyent *typ; 1360 1361 /* 1362 * Destroy any previous session state. 1363 * There shouldn't be any, but just in case... 1364 */ 1365 for (sp = sessions; sp; sp = snext) { 1366 snext = sp->se_next; 1367 free_session(sp); 1368 } 1369 sessions = 0; 1370 if (start_session_db()) 1371 return (state_func_t) single_user; 1372 1373 /* 1374 * Allocate a session entry for each active port. 1375 * Note that sp starts at 0. 1376 */ 1377 while ((typ = getttyent()) != NULL) 1378 if ((snext = new_session(sp, typ)) != NULL) 1379 sp = snext; 1380 1381 endttyent(); 1382 1383 return (state_func_t) multi_user; 1384 } 1385 1386 /* 1387 * Start a window system running. 1388 */ 1389 static void 1390 start_window_system(session_t *sp) 1391 { 1392 pid_t pid; 1393 sigset_t mask; 1394 char term[64], *env[2]; 1395 int status; 1396 1397 if ((pid = fork()) == -1) { 1398 emergency("can't fork for window system on port %s: %m", 1399 sp->se_device); 1400 /* hope that getty fails and we can try again */ 1401 return; 1402 } 1403 if (pid) { 1404 waitpid(-1, &status, 0); 1405 return; 1406 } 1407 1408 /* reparent window process to the init to not make a zombie on exit */ 1409 if ((pid = fork()) == -1) { 1410 emergency("can't fork for window system on port %s: %m", 1411 sp->se_device); 1412 _exit(1); 1413 } 1414 if (pid) 1415 _exit(0); 1416 1417 sigemptyset(&mask); 1418 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1419 1420 if (setsid() < 0) 1421 emergency("setsid failed (window) %m"); 1422 1423 #ifdef LOGIN_CAP 1424 setprocresources(RESOURCE_WINDOW); 1425 #endif 1426 if (sp->se_type) { 1427 /* Don't use malloc after fork */ 1428 strcpy(term, "TERM="); 1429 strlcat(term, sp->se_type, sizeof(term)); 1430 env[0] = term; 1431 env[1] = 0; 1432 } 1433 else 1434 env[0] = 0; 1435 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1436 stall("can't exec window system '%s' for port %s: %m", 1437 sp->se_window_argv[0], sp->se_device); 1438 _exit(1); 1439 } 1440 1441 /* 1442 * Start a login session running. 1443 */ 1444 static pid_t 1445 start_getty(session_t *sp) 1446 { 1447 pid_t pid; 1448 sigset_t mask; 1449 time_t current_time = time((time_t *) 0); 1450 int too_quick = 0; 1451 char term[64], *env[2]; 1452 1453 if (current_time >= sp->se_started && 1454 current_time - sp->se_started < GETTY_SPACING) { 1455 if (++sp->se_nspace > GETTY_NSPACE) { 1456 sp->se_nspace = 0; 1457 too_quick = 1; 1458 } 1459 } else 1460 sp->se_nspace = 0; 1461 1462 /* 1463 * fork(), not vfork() -- we can't afford to block. 1464 */ 1465 if ((pid = fork()) == -1) { 1466 emergency("can't fork for getty on port %s: %m", sp->se_device); 1467 return -1; 1468 } 1469 1470 if (pid) 1471 return pid; 1472 1473 if (too_quick) { 1474 warning("getty repeating too quickly on port %s, sleeping %d secs", 1475 sp->se_device, GETTY_SLEEP); 1476 sleep((unsigned) GETTY_SLEEP); 1477 } 1478 1479 if (sp->se_window) { 1480 start_window_system(sp); 1481 sleep(WINDOW_WAIT); 1482 } 1483 1484 sigemptyset(&mask); 1485 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1486 1487 #ifdef LOGIN_CAP 1488 setprocresources(RESOURCE_GETTY); 1489 #endif 1490 if (sp->se_type) { 1491 /* Don't use malloc after fork */ 1492 strcpy(term, "TERM="); 1493 strlcat(term, sp->se_type, sizeof(term)); 1494 env[0] = term; 1495 env[1] = 0; 1496 } else 1497 env[0] = 0; 1498 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1499 stall("can't exec getty '%s' for port %s: %m", 1500 sp->se_getty_argv[0], sp->se_device); 1501 _exit(1); 1502 } 1503 1504 /* 1505 * Return 1 if the session is defined as "onifexists" 1506 * or "onifconsole" and the device node does not exist. 1507 */ 1508 static int 1509 session_has_no_tty(session_t *sp) 1510 { 1511 int fd; 1512 1513 if ((sp->se_flags & SE_IFEXISTS) == 0 && 1514 (sp->se_flags & SE_IFCONSOLE) == 0) 1515 return (0); 1516 1517 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0); 1518 if (fd < 0) { 1519 if (errno == ENOENT) 1520 return (1); 1521 return (0); 1522 } 1523 1524 close(fd); 1525 return (0); 1526 } 1527 1528 /* 1529 * Collect exit status for a child. 1530 * If an exiting login, start a new login running. 1531 */ 1532 static void 1533 collect_child(pid_t pid) 1534 { 1535 session_t *sp, *sprev, *snext; 1536 1537 if (! sessions) 1538 return; 1539 1540 if (! (sp = find_session(pid))) 1541 return; 1542 1543 del_session(sp); 1544 sp->se_process = 0; 1545 1546 if (sp->se_flags & SE_SHUTDOWN || 1547 session_has_no_tty(sp)) { 1548 if ((sprev = sp->se_prev) != NULL) 1549 sprev->se_next = sp->se_next; 1550 else 1551 sessions = sp->se_next; 1552 if ((snext = sp->se_next) != NULL) 1553 snext->se_prev = sp->se_prev; 1554 free_session(sp); 1555 return; 1556 } 1557 1558 if ((pid = start_getty(sp)) == -1) { 1559 /* serious trouble */ 1560 requested_transition = clean_ttys; 1561 return; 1562 } 1563 1564 sp->se_process = pid; 1565 sp->se_started = time((time_t *) 0); 1566 add_session(sp); 1567 } 1568 1569 /* 1570 * Catch a signal and request a state transition. 1571 */ 1572 static void 1573 transition_handler(int sig) 1574 { 1575 1576 switch (sig) { 1577 case SIGHUP: 1578 if (current_state == read_ttys || current_state == multi_user || 1579 current_state == clean_ttys || current_state == catatonia) 1580 requested_transition = clean_ttys; 1581 break; 1582 case SIGWINCH: 1583 case SIGUSR2: 1584 howto = sig == SIGUSR2 ? RB_POWEROFF : RB_POWERCYCLE; 1585 case SIGUSR1: 1586 howto |= RB_HALT; 1587 case SIGINT: 1588 Reboot = TRUE; 1589 case SIGTERM: 1590 if (current_state == read_ttys || current_state == multi_user || 1591 current_state == clean_ttys || current_state == catatonia) 1592 requested_transition = death; 1593 else 1594 requested_transition = death_single; 1595 break; 1596 case SIGTSTP: 1597 if (current_state == runcom || current_state == read_ttys || 1598 current_state == clean_ttys || 1599 current_state == multi_user || current_state == catatonia) 1600 requested_transition = catatonia; 1601 break; 1602 case SIGEMT: 1603 requested_transition = reroot; 1604 break; 1605 default: 1606 requested_transition = 0; 1607 break; 1608 } 1609 } 1610 1611 /* 1612 * Take the system multiuser. 1613 */ 1614 static state_func_t 1615 multi_user(void) 1616 { 1617 pid_t pid; 1618 session_t *sp; 1619 1620 requested_transition = 0; 1621 1622 /* 1623 * If the administrator has not set the security level to -1 1624 * to indicate that the kernel should not run multiuser in secure 1625 * mode, and the run script has not set a higher level of security 1626 * than level 1, then put the kernel into secure mode. 1627 */ 1628 if (getsecuritylevel() == 0) 1629 setsecuritylevel(1); 1630 1631 for (sp = sessions; sp; sp = sp->se_next) { 1632 if (sp->se_process) 1633 continue; 1634 if (session_has_no_tty(sp)) 1635 continue; 1636 if ((pid = start_getty(sp)) == -1) { 1637 /* serious trouble */ 1638 requested_transition = clean_ttys; 1639 break; 1640 } 1641 sp->se_process = pid; 1642 sp->se_started = time((time_t *) 0); 1643 add_session(sp); 1644 } 1645 1646 while (!requested_transition) 1647 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1648 collect_child(pid); 1649 1650 return (state_func_t) requested_transition; 1651 } 1652 1653 /* 1654 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1655 */ 1656 static state_func_t 1657 clean_ttys(void) 1658 { 1659 session_t *sp, *sprev; 1660 struct ttyent *typ; 1661 int devlen; 1662 char *old_getty, *old_window, *old_type; 1663 1664 /* 1665 * mark all sessions for death, (!SE_PRESENT) 1666 * as we find or create new ones they'll be marked as keepers, 1667 * we'll later nuke all the ones not found in /etc/ttys 1668 */ 1669 for (sp = sessions; sp != NULL; sp = sp->se_next) 1670 sp->se_flags &= ~SE_PRESENT; 1671 1672 devlen = sizeof(_PATH_DEV) - 1; 1673 while ((typ = getttyent()) != NULL) { 1674 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1675 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1676 break; 1677 1678 if (sp) { 1679 /* we want this one to live */ 1680 sp->se_flags |= SE_PRESENT; 1681 if ((typ->ty_status & TTY_ON) == 0 || 1682 typ->ty_getty == 0) { 1683 sp->se_flags |= SE_SHUTDOWN; 1684 kill(sp->se_process, SIGHUP); 1685 continue; 1686 } 1687 sp->se_flags &= ~SE_SHUTDOWN; 1688 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1689 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1690 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1691 if (setupargv(sp, typ) == 0) { 1692 warning("can't parse getty for port %s", 1693 sp->se_device); 1694 sp->se_flags |= SE_SHUTDOWN; 1695 kill(sp->se_process, SIGHUP); 1696 } 1697 else if ( !old_getty 1698 || (!old_type && sp->se_type) 1699 || (old_type && !sp->se_type) 1700 || (!old_window && sp->se_window) 1701 || (old_window && !sp->se_window) 1702 || (strcmp(old_getty, sp->se_getty) != 0) 1703 || (old_window && strcmp(old_window, sp->se_window) != 0) 1704 || (old_type && strcmp(old_type, sp->se_type) != 0) 1705 ) { 1706 /* Don't set SE_SHUTDOWN here */ 1707 sp->se_nspace = 0; 1708 sp->se_started = 0; 1709 kill(sp->se_process, SIGHUP); 1710 } 1711 if (old_getty) 1712 free(old_getty); 1713 if (old_window) 1714 free(old_window); 1715 if (old_type) 1716 free(old_type); 1717 continue; 1718 } 1719 1720 new_session(sprev, typ); 1721 } 1722 1723 endttyent(); 1724 1725 /* 1726 * sweep through and kill all deleted sessions 1727 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1728 */ 1729 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1730 if ((sp->se_flags & SE_PRESENT) == 0) { 1731 sp->se_flags |= SE_SHUTDOWN; 1732 kill(sp->se_process, SIGHUP); 1733 } 1734 } 1735 1736 return (state_func_t) multi_user; 1737 } 1738 1739 /* 1740 * Block further logins. 1741 */ 1742 static state_func_t 1743 catatonia(void) 1744 { 1745 session_t *sp; 1746 1747 for (sp = sessions; sp; sp = sp->se_next) 1748 sp->se_flags |= SE_SHUTDOWN; 1749 1750 return (state_func_t) multi_user; 1751 } 1752 1753 /* 1754 * Note SIGALRM. 1755 */ 1756 static void 1757 alrm_handler(int sig) 1758 { 1759 1760 (void)sig; 1761 clang = 1; 1762 } 1763 1764 /* 1765 * Bring the system down to single user. 1766 */ 1767 static state_func_t 1768 death(void) 1769 { 1770 int block, blocked; 1771 size_t len; 1772 1773 /* Temporarily block suspend. */ 1774 len = sizeof(blocked); 1775 block = 1; 1776 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1777 &block, sizeof(block)) == -1) 1778 blocked = 0; 1779 1780 /* 1781 * Also revoke the TTY here. Because runshutdown() may reopen 1782 * the TTY whose getty we're killing here, there is no guarantee 1783 * runshutdown() will perform the initial open() call, causing 1784 * the terminal attributes to be misconfigured. 1785 */ 1786 revoke_ttys(); 1787 1788 /* Try to run the rc.shutdown script within a period of time */ 1789 runshutdown(); 1790 1791 /* Unblock suspend if we blocked it. */ 1792 if (!blocked) 1793 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1794 &blocked, sizeof(blocked)); 1795 1796 return (state_func_t) death_single; 1797 } 1798 1799 /* 1800 * Do what is necessary to reinitialize single user mode or reboot 1801 * from an incomplete state. 1802 */ 1803 static state_func_t 1804 death_single(void) 1805 { 1806 int i; 1807 pid_t pid; 1808 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1809 1810 revoke(_PATH_CONSOLE); 1811 1812 for (i = 0; i < 2; ++i) { 1813 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1814 return (state_func_t) single_user; 1815 1816 clang = 0; 1817 alarm(DEATH_WATCH); 1818 do 1819 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1820 collect_child(pid); 1821 while (clang == 0 && errno != ECHILD); 1822 1823 if (errno == ECHILD) 1824 return (state_func_t) single_user; 1825 } 1826 1827 warning("some processes would not die; ps axl advised"); 1828 1829 return (state_func_t) single_user; 1830 } 1831 1832 static void 1833 revoke_ttys(void) 1834 { 1835 session_t *sp; 1836 1837 for (sp = sessions; sp; sp = sp->se_next) { 1838 sp->se_flags |= SE_SHUTDOWN; 1839 kill(sp->se_process, SIGHUP); 1840 revoke(sp->se_device); 1841 } 1842 } 1843 1844 /* 1845 * Run the system shutdown script. 1846 * 1847 * Exit codes: XXX I should document more 1848 * -2 shutdown script terminated abnormally 1849 * -1 fatal error - can't run script 1850 * 0 good. 1851 * >0 some error (exit code) 1852 */ 1853 static int 1854 runshutdown(void) 1855 { 1856 pid_t pid, wpid; 1857 int status; 1858 int shutdowntimeout; 1859 size_t len; 1860 char *argv[4]; 1861 const char *shell; 1862 struct sigaction sa; 1863 struct stat sb; 1864 1865 /* 1866 * rc.shutdown is optional, so to prevent any unnecessary 1867 * complaints from the shell we simply don't run it if the 1868 * file does not exist. If the stat() here fails for other 1869 * reasons, we'll let the shell complain. 1870 */ 1871 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1872 return 0; 1873 1874 shell = get_shell(); 1875 1876 if ((pid = fork()) == 0) { 1877 sigemptyset(&sa.sa_mask); 1878 sa.sa_flags = 0; 1879 sa.sa_handler = SIG_IGN; 1880 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1881 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1882 1883 open_console(); 1884 1885 char _sh[] = "sh"; 1886 char _reboot[] = "reboot"; 1887 char _single[] = "single"; 1888 char _path_rundown[] = _PATH_RUNDOWN; 1889 1890 argv[0] = _sh; 1891 argv[1] = _path_rundown; 1892 argv[2] = Reboot ? _reboot : _single; 1893 argv[3] = 0; 1894 1895 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1896 1897 #ifdef LOGIN_CAP 1898 setprocresources(RESOURCE_RC); 1899 #endif 1900 execv(shell, argv); 1901 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1902 _exit(1); /* force single user mode */ 1903 } 1904 1905 if (pid == -1) { 1906 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1907 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1908 continue; 1909 sleep(STALL_TIMEOUT); 1910 return -1; 1911 } 1912 1913 len = sizeof(shutdowntimeout); 1914 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1915 NULL, 0) == -1 || shutdowntimeout < 2) 1916 shutdowntimeout = DEATH_SCRIPT; 1917 alarm(shutdowntimeout); 1918 clang = 0; 1919 /* 1920 * Copied from single_user(). This is a bit paranoid. 1921 * Use the same ALRM handler. 1922 */ 1923 do { 1924 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1925 collect_child(wpid); 1926 if (clang == 1) { 1927 /* we were waiting for the sub-shell */ 1928 kill(wpid, SIGTERM); 1929 warning("timeout expired for %s on %s: %m; going to " 1930 "single user mode", shell, _PATH_RUNDOWN); 1931 return -1; 1932 } 1933 if (wpid == -1) { 1934 if (errno == EINTR) 1935 continue; 1936 warning("wait for %s on %s failed: %m; going to " 1937 "single user mode", shell, _PATH_RUNDOWN); 1938 return -1; 1939 } 1940 if (wpid == pid && WIFSTOPPED(status)) { 1941 warning("init: %s on %s stopped, restarting\n", 1942 shell, _PATH_RUNDOWN); 1943 kill(pid, SIGCONT); 1944 wpid = -1; 1945 } 1946 } while (wpid != pid && !clang); 1947 1948 /* Turn off the alarm */ 1949 alarm(0); 1950 1951 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1952 requested_transition == catatonia) { 1953 /* 1954 * /etc/rc.shutdown executed /sbin/reboot; 1955 * wait for the end quietly 1956 */ 1957 sigset_t s; 1958 1959 sigfillset(&s); 1960 for (;;) 1961 sigsuspend(&s); 1962 } 1963 1964 if (!WIFEXITED(status)) { 1965 warning("%s on %s terminated abnormally, going to " 1966 "single user mode", shell, _PATH_RUNDOWN); 1967 return -2; 1968 } 1969 1970 if ((status = WEXITSTATUS(status)) != 0) 1971 warning("%s returned status %d", _PATH_RUNDOWN, status); 1972 1973 return status; 1974 } 1975 1976 static char * 1977 strk(char *p) 1978 { 1979 static char *t; 1980 char *q; 1981 int c; 1982 1983 if (p) 1984 t = p; 1985 if (!t) 1986 return 0; 1987 1988 c = *t; 1989 while (c == ' ' || c == '\t' ) 1990 c = *++t; 1991 if (!c) { 1992 t = 0; 1993 return 0; 1994 } 1995 q = t; 1996 if (c == '\'') { 1997 c = *++t; 1998 q = t; 1999 while (c && c != '\'') 2000 c = *++t; 2001 if (!c) /* unterminated string */ 2002 q = t = 0; 2003 else 2004 *t++ = 0; 2005 } else { 2006 while (c && c != ' ' && c != '\t' ) 2007 c = *++t; 2008 *t++ = 0; 2009 if (!c) 2010 t = 0; 2011 } 2012 return q; 2013 } 2014 2015 #ifdef LOGIN_CAP 2016 static void 2017 setprocresources(const char *cname) 2018 { 2019 login_cap_t *lc; 2020 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 2021 setusercontext(lc, (struct passwd*)NULL, 0, 2022 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2023 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2024 login_close(lc); 2025 } 2026 } 2027 #endif 2028