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 error, 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 1090 /* 1091 * Try to directly execute the script first. If it 1092 * fails, try the old method of passing the script path 1093 * to sh(1). Don't complain if it fails because of 1094 * the missing execute bit. 1095 */ 1096 error = access(script, X_OK); 1097 if (error == 0) { 1098 execv(script, argv + 1); 1099 warning("can't exec %s: %m", script); 1100 } else if (errno != EACCES) { 1101 warning("can't access %s: %m", script); 1102 } 1103 1104 execv(shell, argv); 1105 stall("can't exec %s for %s: %m", shell, script); 1106 _exit(1); /* force single user mode */ 1107 } 1108 1109 if (pid == -1) { 1110 emergency("can't fork for %s on %s: %m", shell, script); 1111 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1112 continue; 1113 sleep(STALL_TIMEOUT); 1114 return (state_func_t) single_user; 1115 } 1116 1117 /* 1118 * Copied from single_user(). This is a bit paranoid. 1119 */ 1120 requested_transition = 0; 1121 do { 1122 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1123 collect_child(wpid); 1124 if (wpid == -1) { 1125 if (requested_transition == death_single || 1126 requested_transition == reroot) 1127 return (state_func_t) requested_transition; 1128 if (errno == EINTR) 1129 continue; 1130 warning("wait for %s on %s failed: %m; going to " 1131 "single user mode", shell, script); 1132 return (state_func_t) single_user; 1133 } 1134 if (wpid == pid && WIFSTOPPED(status)) { 1135 warning("init: %s on %s stopped, restarting\n", 1136 shell, script); 1137 kill(pid, SIGCONT); 1138 wpid = -1; 1139 } 1140 } while (wpid != pid); 1141 1142 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1143 requested_transition == catatonia) { 1144 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1145 sigset_t s; 1146 1147 sigfillset(&s); 1148 for (;;) 1149 sigsuspend(&s); 1150 } 1151 1152 if (!WIFEXITED(status)) { 1153 warning("%s on %s terminated abnormally, going to single " 1154 "user mode", shell, script); 1155 return (state_func_t) single_user; 1156 } 1157 1158 if (WEXITSTATUS(status)) 1159 return (state_func_t) single_user; 1160 1161 return (state_func_t) 0; 1162 } 1163 1164 /* 1165 * Open the session database. 1166 * 1167 * NB: We could pass in the size here; is it necessary? 1168 */ 1169 static int 1170 start_session_db(void) 1171 { 1172 if (session_db && (*session_db->close)(session_db)) 1173 emergency("session database close: %s", strerror(errno)); 1174 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 1175 emergency("session database open: %s", strerror(errno)); 1176 return (1); 1177 } 1178 return (0); 1179 1180 } 1181 1182 /* 1183 * Add a new login session. 1184 */ 1185 static void 1186 add_session(session_t *sp) 1187 { 1188 DBT key; 1189 DBT data; 1190 1191 key.data = &sp->se_process; 1192 key.size = sizeof sp->se_process; 1193 data.data = &sp; 1194 data.size = sizeof sp; 1195 1196 if ((*session_db->put)(session_db, &key, &data, 0)) 1197 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1198 } 1199 1200 /* 1201 * Delete an old login session. 1202 */ 1203 static void 1204 del_session(session_t *sp) 1205 { 1206 DBT key; 1207 1208 key.data = &sp->se_process; 1209 key.size = sizeof sp->se_process; 1210 1211 if ((*session_db->del)(session_db, &key, 0)) 1212 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1213 } 1214 1215 /* 1216 * Look up a login session by pid. 1217 */ 1218 static session_t * 1219 find_session(pid_t pid) 1220 { 1221 DBT key; 1222 DBT data; 1223 session_t *ret; 1224 1225 key.data = &pid; 1226 key.size = sizeof pid; 1227 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1228 return 0; 1229 bcopy(data.data, (char *)&ret, sizeof(ret)); 1230 return ret; 1231 } 1232 1233 /* 1234 * Construct an argument vector from a command line. 1235 */ 1236 static char ** 1237 construct_argv(char *command) 1238 { 1239 int argc = 0; 1240 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1241 * sizeof (char *)); 1242 1243 if ((argv[argc++] = strk(command)) == NULL) { 1244 free(argv); 1245 return (NULL); 1246 } 1247 while ((argv[argc++] = strk((char *) 0)) != NULL) 1248 continue; 1249 return argv; 1250 } 1251 1252 /* 1253 * Deallocate a session descriptor. 1254 */ 1255 static void 1256 free_session(session_t *sp) 1257 { 1258 free(sp->se_device); 1259 if (sp->se_getty) { 1260 free(sp->se_getty); 1261 free(sp->se_getty_argv_space); 1262 free(sp->se_getty_argv); 1263 } 1264 if (sp->se_window) { 1265 free(sp->se_window); 1266 free(sp->se_window_argv_space); 1267 free(sp->se_window_argv); 1268 } 1269 if (sp->se_type) 1270 free(sp->se_type); 1271 free(sp); 1272 } 1273 1274 /* 1275 * Allocate a new session descriptor. 1276 * Mark it SE_PRESENT. 1277 */ 1278 static session_t * 1279 new_session(session_t *sprev, struct ttyent *typ) 1280 { 1281 session_t *sp; 1282 1283 if ((typ->ty_status & TTY_ON) == 0 || 1284 typ->ty_name == 0 || 1285 typ->ty_getty == 0) 1286 return 0; 1287 1288 sp = (session_t *) calloc(1, sizeof (session_t)); 1289 1290 sp->se_flags |= SE_PRESENT; 1291 1292 if ((typ->ty_status & TTY_IFEXISTS) != 0) 1293 sp->se_flags |= SE_IFEXISTS; 1294 1295 if ((typ->ty_status & TTY_IFCONSOLE) != 0) 1296 sp->se_flags |= SE_IFCONSOLE; 1297 1298 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0) 1299 err(1, "asprintf"); 1300 1301 if (setupargv(sp, typ) == 0) { 1302 free_session(sp); 1303 return (0); 1304 } 1305 1306 sp->se_next = 0; 1307 if (sprev == NULL) { 1308 sessions = sp; 1309 sp->se_prev = 0; 1310 } else { 1311 sprev->se_next = sp; 1312 sp->se_prev = sprev; 1313 } 1314 1315 return sp; 1316 } 1317 1318 /* 1319 * Calculate getty and if useful window argv vectors. 1320 */ 1321 static int 1322 setupargv(session_t *sp, struct ttyent *typ) 1323 { 1324 1325 if (sp->se_getty) { 1326 free(sp->se_getty); 1327 free(sp->se_getty_argv_space); 1328 free(sp->se_getty_argv); 1329 } 1330 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0) 1331 err(1, "asprintf"); 1332 sp->se_getty_argv_space = strdup(sp->se_getty); 1333 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1334 if (sp->se_getty_argv == NULL) { 1335 warning("can't parse getty for port %s", sp->se_device); 1336 free(sp->se_getty); 1337 free(sp->se_getty_argv_space); 1338 sp->se_getty = sp->se_getty_argv_space = 0; 1339 return (0); 1340 } 1341 if (sp->se_window) { 1342 free(sp->se_window); 1343 free(sp->se_window_argv_space); 1344 free(sp->se_window_argv); 1345 } 1346 sp->se_window = sp->se_window_argv_space = 0; 1347 sp->se_window_argv = 0; 1348 if (typ->ty_window) { 1349 sp->se_window = strdup(typ->ty_window); 1350 sp->se_window_argv_space = strdup(sp->se_window); 1351 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1352 if (sp->se_window_argv == NULL) { 1353 warning("can't parse window for port %s", 1354 sp->se_device); 1355 free(sp->se_window_argv_space); 1356 free(sp->se_window); 1357 sp->se_window = sp->se_window_argv_space = 0; 1358 return (0); 1359 } 1360 } 1361 if (sp->se_type) 1362 free(sp->se_type); 1363 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1364 return (1); 1365 } 1366 1367 /* 1368 * Walk the list of ttys and create sessions for each active line. 1369 */ 1370 static state_func_t 1371 read_ttys(void) 1372 { 1373 session_t *sp, *snext; 1374 struct ttyent *typ; 1375 1376 /* 1377 * Destroy any previous session state. 1378 * There shouldn't be any, but just in case... 1379 */ 1380 for (sp = sessions; sp; sp = snext) { 1381 snext = sp->se_next; 1382 free_session(sp); 1383 } 1384 sessions = 0; 1385 if (start_session_db()) 1386 return (state_func_t) single_user; 1387 1388 /* 1389 * Allocate a session entry for each active port. 1390 * Note that sp starts at 0. 1391 */ 1392 while ((typ = getttyent()) != NULL) 1393 if ((snext = new_session(sp, typ)) != NULL) 1394 sp = snext; 1395 1396 endttyent(); 1397 1398 return (state_func_t) multi_user; 1399 } 1400 1401 /* 1402 * Start a window system running. 1403 */ 1404 static void 1405 start_window_system(session_t *sp) 1406 { 1407 pid_t pid; 1408 sigset_t mask; 1409 char term[64], *env[2]; 1410 int status; 1411 1412 if ((pid = fork()) == -1) { 1413 emergency("can't fork for window system on port %s: %m", 1414 sp->se_device); 1415 /* hope that getty fails and we can try again */ 1416 return; 1417 } 1418 if (pid) { 1419 waitpid(-1, &status, 0); 1420 return; 1421 } 1422 1423 /* reparent window process to the init to not make a zombie on exit */ 1424 if ((pid = fork()) == -1) { 1425 emergency("can't fork for window system on port %s: %m", 1426 sp->se_device); 1427 _exit(1); 1428 } 1429 if (pid) 1430 _exit(0); 1431 1432 sigemptyset(&mask); 1433 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1434 1435 if (setsid() < 0) 1436 emergency("setsid failed (window) %m"); 1437 1438 #ifdef LOGIN_CAP 1439 setprocresources(RESOURCE_WINDOW); 1440 #endif 1441 if (sp->se_type) { 1442 /* Don't use malloc after fork */ 1443 strcpy(term, "TERM="); 1444 strlcat(term, sp->se_type, sizeof(term)); 1445 env[0] = term; 1446 env[1] = 0; 1447 } 1448 else 1449 env[0] = 0; 1450 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1451 stall("can't exec window system '%s' for port %s: %m", 1452 sp->se_window_argv[0], sp->se_device); 1453 _exit(1); 1454 } 1455 1456 /* 1457 * Start a login session running. 1458 */ 1459 static pid_t 1460 start_getty(session_t *sp) 1461 { 1462 pid_t pid; 1463 sigset_t mask; 1464 time_t current_time = time((time_t *) 0); 1465 int too_quick = 0; 1466 char term[64], *env[2]; 1467 1468 if (current_time >= sp->se_started && 1469 current_time - sp->se_started < GETTY_SPACING) { 1470 if (++sp->se_nspace > GETTY_NSPACE) { 1471 sp->se_nspace = 0; 1472 too_quick = 1; 1473 } 1474 } else 1475 sp->se_nspace = 0; 1476 1477 /* 1478 * fork(), not vfork() -- we can't afford to block. 1479 */ 1480 if ((pid = fork()) == -1) { 1481 emergency("can't fork for getty on port %s: %m", sp->se_device); 1482 return -1; 1483 } 1484 1485 if (pid) 1486 return pid; 1487 1488 if (too_quick) { 1489 warning("getty repeating too quickly on port %s, sleeping %d secs", 1490 sp->se_device, GETTY_SLEEP); 1491 sleep((unsigned) GETTY_SLEEP); 1492 } 1493 1494 if (sp->se_window) { 1495 start_window_system(sp); 1496 sleep(WINDOW_WAIT); 1497 } 1498 1499 sigemptyset(&mask); 1500 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1501 1502 #ifdef LOGIN_CAP 1503 setprocresources(RESOURCE_GETTY); 1504 #endif 1505 if (sp->se_type) { 1506 /* Don't use malloc after fork */ 1507 strcpy(term, "TERM="); 1508 strlcat(term, sp->se_type, sizeof(term)); 1509 env[0] = term; 1510 env[1] = 0; 1511 } else 1512 env[0] = 0; 1513 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1514 stall("can't exec getty '%s' for port %s: %m", 1515 sp->se_getty_argv[0], sp->se_device); 1516 _exit(1); 1517 } 1518 1519 /* 1520 * Return 1 if the session is defined as "onifexists" 1521 * or "onifconsole" and the device node does not exist. 1522 */ 1523 static int 1524 session_has_no_tty(session_t *sp) 1525 { 1526 int fd; 1527 1528 if ((sp->se_flags & SE_IFEXISTS) == 0 && 1529 (sp->se_flags & SE_IFCONSOLE) == 0) 1530 return (0); 1531 1532 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0); 1533 if (fd < 0) { 1534 if (errno == ENOENT) 1535 return (1); 1536 return (0); 1537 } 1538 1539 close(fd); 1540 return (0); 1541 } 1542 1543 /* 1544 * Collect exit status for a child. 1545 * If an exiting login, start a new login running. 1546 */ 1547 static void 1548 collect_child(pid_t pid) 1549 { 1550 session_t *sp, *sprev, *snext; 1551 1552 if (! sessions) 1553 return; 1554 1555 if (! (sp = find_session(pid))) 1556 return; 1557 1558 del_session(sp); 1559 sp->se_process = 0; 1560 1561 if (sp->se_flags & SE_SHUTDOWN || 1562 session_has_no_tty(sp)) { 1563 if ((sprev = sp->se_prev) != NULL) 1564 sprev->se_next = sp->se_next; 1565 else 1566 sessions = sp->se_next; 1567 if ((snext = sp->se_next) != NULL) 1568 snext->se_prev = sp->se_prev; 1569 free_session(sp); 1570 return; 1571 } 1572 1573 if ((pid = start_getty(sp)) == -1) { 1574 /* serious trouble */ 1575 requested_transition = clean_ttys; 1576 return; 1577 } 1578 1579 sp->se_process = pid; 1580 sp->se_started = time((time_t *) 0); 1581 add_session(sp); 1582 } 1583 1584 /* 1585 * Catch a signal and request a state transition. 1586 */ 1587 static void 1588 transition_handler(int sig) 1589 { 1590 1591 switch (sig) { 1592 case SIGHUP: 1593 if (current_state == read_ttys || current_state == multi_user || 1594 current_state == clean_ttys || current_state == catatonia) 1595 requested_transition = clean_ttys; 1596 break; 1597 case SIGWINCH: 1598 case SIGUSR2: 1599 howto = sig == SIGUSR2 ? RB_POWEROFF : RB_POWERCYCLE; 1600 case SIGUSR1: 1601 howto |= RB_HALT; 1602 case SIGINT: 1603 Reboot = TRUE; 1604 case SIGTERM: 1605 if (current_state == read_ttys || current_state == multi_user || 1606 current_state == clean_ttys || current_state == catatonia) 1607 requested_transition = death; 1608 else 1609 requested_transition = death_single; 1610 break; 1611 case SIGTSTP: 1612 if (current_state == runcom || current_state == read_ttys || 1613 current_state == clean_ttys || 1614 current_state == multi_user || current_state == catatonia) 1615 requested_transition = catatonia; 1616 break; 1617 case SIGEMT: 1618 requested_transition = reroot; 1619 break; 1620 default: 1621 requested_transition = 0; 1622 break; 1623 } 1624 } 1625 1626 /* 1627 * Take the system multiuser. 1628 */ 1629 static state_func_t 1630 multi_user(void) 1631 { 1632 pid_t pid; 1633 session_t *sp; 1634 1635 requested_transition = 0; 1636 1637 /* 1638 * If the administrator has not set the security level to -1 1639 * to indicate that the kernel should not run multiuser in secure 1640 * mode, and the run script has not set a higher level of security 1641 * than level 1, then put the kernel into secure mode. 1642 */ 1643 if (getsecuritylevel() == 0) 1644 setsecuritylevel(1); 1645 1646 for (sp = sessions; sp; sp = sp->se_next) { 1647 if (sp->se_process) 1648 continue; 1649 if (session_has_no_tty(sp)) 1650 continue; 1651 if ((pid = start_getty(sp)) == -1) { 1652 /* serious trouble */ 1653 requested_transition = clean_ttys; 1654 break; 1655 } 1656 sp->se_process = pid; 1657 sp->se_started = time((time_t *) 0); 1658 add_session(sp); 1659 } 1660 1661 while (!requested_transition) 1662 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1663 collect_child(pid); 1664 1665 return (state_func_t) requested_transition; 1666 } 1667 1668 /* 1669 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1670 */ 1671 static state_func_t 1672 clean_ttys(void) 1673 { 1674 session_t *sp, *sprev; 1675 struct ttyent *typ; 1676 int devlen; 1677 char *old_getty, *old_window, *old_type; 1678 1679 /* 1680 * mark all sessions for death, (!SE_PRESENT) 1681 * as we find or create new ones they'll be marked as keepers, 1682 * we'll later nuke all the ones not found in /etc/ttys 1683 */ 1684 for (sp = sessions; sp != NULL; sp = sp->se_next) 1685 sp->se_flags &= ~SE_PRESENT; 1686 1687 devlen = sizeof(_PATH_DEV) - 1; 1688 while ((typ = getttyent()) != NULL) { 1689 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1690 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1691 break; 1692 1693 if (sp) { 1694 /* we want this one to live */ 1695 sp->se_flags |= SE_PRESENT; 1696 if ((typ->ty_status & TTY_ON) == 0 || 1697 typ->ty_getty == 0) { 1698 sp->se_flags |= SE_SHUTDOWN; 1699 kill(sp->se_process, SIGHUP); 1700 continue; 1701 } 1702 sp->se_flags &= ~SE_SHUTDOWN; 1703 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1704 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1705 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1706 if (setupargv(sp, typ) == 0) { 1707 warning("can't parse getty for port %s", 1708 sp->se_device); 1709 sp->se_flags |= SE_SHUTDOWN; 1710 kill(sp->se_process, SIGHUP); 1711 } 1712 else if ( !old_getty 1713 || (!old_type && sp->se_type) 1714 || (old_type && !sp->se_type) 1715 || (!old_window && sp->se_window) 1716 || (old_window && !sp->se_window) 1717 || (strcmp(old_getty, sp->se_getty) != 0) 1718 || (old_window && strcmp(old_window, sp->se_window) != 0) 1719 || (old_type && strcmp(old_type, sp->se_type) != 0) 1720 ) { 1721 /* Don't set SE_SHUTDOWN here */ 1722 sp->se_nspace = 0; 1723 sp->se_started = 0; 1724 kill(sp->se_process, SIGHUP); 1725 } 1726 if (old_getty) 1727 free(old_getty); 1728 if (old_window) 1729 free(old_window); 1730 if (old_type) 1731 free(old_type); 1732 continue; 1733 } 1734 1735 new_session(sprev, typ); 1736 } 1737 1738 endttyent(); 1739 1740 /* 1741 * sweep through and kill all deleted sessions 1742 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1743 */ 1744 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1745 if ((sp->se_flags & SE_PRESENT) == 0) { 1746 sp->se_flags |= SE_SHUTDOWN; 1747 kill(sp->se_process, SIGHUP); 1748 } 1749 } 1750 1751 return (state_func_t) multi_user; 1752 } 1753 1754 /* 1755 * Block further logins. 1756 */ 1757 static state_func_t 1758 catatonia(void) 1759 { 1760 session_t *sp; 1761 1762 for (sp = sessions; sp; sp = sp->se_next) 1763 sp->se_flags |= SE_SHUTDOWN; 1764 1765 return (state_func_t) multi_user; 1766 } 1767 1768 /* 1769 * Note SIGALRM. 1770 */ 1771 static void 1772 alrm_handler(int sig) 1773 { 1774 1775 (void)sig; 1776 clang = 1; 1777 } 1778 1779 /* 1780 * Bring the system down to single user. 1781 */ 1782 static state_func_t 1783 death(void) 1784 { 1785 int block, blocked; 1786 size_t len; 1787 1788 /* Temporarily block suspend. */ 1789 len = sizeof(blocked); 1790 block = 1; 1791 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1792 &block, sizeof(block)) == -1) 1793 blocked = 0; 1794 1795 /* 1796 * Also revoke the TTY here. Because runshutdown() may reopen 1797 * the TTY whose getty we're killing here, there is no guarantee 1798 * runshutdown() will perform the initial open() call, causing 1799 * the terminal attributes to be misconfigured. 1800 */ 1801 revoke_ttys(); 1802 1803 /* Try to run the rc.shutdown script within a period of time */ 1804 runshutdown(); 1805 1806 /* Unblock suspend if we blocked it. */ 1807 if (!blocked) 1808 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1809 &blocked, sizeof(blocked)); 1810 1811 return (state_func_t) death_single; 1812 } 1813 1814 /* 1815 * Do what is necessary to reinitialize single user mode or reboot 1816 * from an incomplete state. 1817 */ 1818 static state_func_t 1819 death_single(void) 1820 { 1821 int i; 1822 pid_t pid; 1823 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1824 1825 revoke(_PATH_CONSOLE); 1826 1827 for (i = 0; i < 2; ++i) { 1828 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1829 return (state_func_t) single_user; 1830 1831 clang = 0; 1832 alarm(DEATH_WATCH); 1833 do 1834 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1835 collect_child(pid); 1836 while (clang == 0 && errno != ECHILD); 1837 1838 if (errno == ECHILD) 1839 return (state_func_t) single_user; 1840 } 1841 1842 warning("some processes would not die; ps axl advised"); 1843 1844 return (state_func_t) single_user; 1845 } 1846 1847 static void 1848 revoke_ttys(void) 1849 { 1850 session_t *sp; 1851 1852 for (sp = sessions; sp; sp = sp->se_next) { 1853 sp->se_flags |= SE_SHUTDOWN; 1854 kill(sp->se_process, SIGHUP); 1855 revoke(sp->se_device); 1856 } 1857 } 1858 1859 /* 1860 * Run the system shutdown script. 1861 * 1862 * Exit codes: XXX I should document more 1863 * -2 shutdown script terminated abnormally 1864 * -1 fatal error - can't run script 1865 * 0 good. 1866 * >0 some error (exit code) 1867 */ 1868 static int 1869 runshutdown(void) 1870 { 1871 pid_t pid, wpid; 1872 int error, status; 1873 int shutdowntimeout; 1874 size_t len; 1875 char *argv[4]; 1876 const char *shell; 1877 struct sigaction sa; 1878 struct stat sb; 1879 1880 /* 1881 * rc.shutdown is optional, so to prevent any unnecessary 1882 * complaints from the shell we simply don't run it if the 1883 * file does not exist. If the stat() here fails for other 1884 * reasons, we'll let the shell complain. 1885 */ 1886 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1887 return 0; 1888 1889 shell = get_shell(); 1890 1891 if ((pid = fork()) == 0) { 1892 sigemptyset(&sa.sa_mask); 1893 sa.sa_flags = 0; 1894 sa.sa_handler = SIG_IGN; 1895 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1896 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1897 1898 open_console(); 1899 1900 char _sh[] = "sh"; 1901 char _reboot[] = "reboot"; 1902 char _single[] = "single"; 1903 char _path_rundown[] = _PATH_RUNDOWN; 1904 1905 argv[0] = _sh; 1906 argv[1] = _path_rundown; 1907 argv[2] = Reboot ? _reboot : _single; 1908 argv[3] = 0; 1909 1910 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1911 1912 #ifdef LOGIN_CAP 1913 setprocresources(RESOURCE_RC); 1914 #endif 1915 1916 /* 1917 * Try to directly execute the script first. If it 1918 * fails, try the old method of passing the script path 1919 * to sh(1). Don't complain if it fails because of 1920 * the missing execute bit. 1921 */ 1922 error = access(_path_rundown, X_OK); 1923 if (error == 0) { 1924 execv(_path_rundown, argv + 1); 1925 warning("can't exec %s: %m", _path_rundown); 1926 } else if (errno != EACCES) { 1927 warning("can't access %s: %m", _path_rundown); 1928 } 1929 1930 execv(shell, argv); 1931 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1932 _exit(1); /* force single user mode */ 1933 } 1934 1935 if (pid == -1) { 1936 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1937 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1938 continue; 1939 sleep(STALL_TIMEOUT); 1940 return -1; 1941 } 1942 1943 len = sizeof(shutdowntimeout); 1944 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1945 NULL, 0) == -1 || shutdowntimeout < 2) 1946 shutdowntimeout = DEATH_SCRIPT; 1947 alarm(shutdowntimeout); 1948 clang = 0; 1949 /* 1950 * Copied from single_user(). This is a bit paranoid. 1951 * Use the same ALRM handler. 1952 */ 1953 do { 1954 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1955 collect_child(wpid); 1956 if (clang == 1) { 1957 /* we were waiting for the sub-shell */ 1958 kill(wpid, SIGTERM); 1959 warning("timeout expired for %s on %s: %m; going to " 1960 "single user mode", shell, _PATH_RUNDOWN); 1961 return -1; 1962 } 1963 if (wpid == -1) { 1964 if (errno == EINTR) 1965 continue; 1966 warning("wait for %s on %s failed: %m; going to " 1967 "single user mode", shell, _PATH_RUNDOWN); 1968 return -1; 1969 } 1970 if (wpid == pid && WIFSTOPPED(status)) { 1971 warning("init: %s on %s stopped, restarting\n", 1972 shell, _PATH_RUNDOWN); 1973 kill(pid, SIGCONT); 1974 wpid = -1; 1975 } 1976 } while (wpid != pid && !clang); 1977 1978 /* Turn off the alarm */ 1979 alarm(0); 1980 1981 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1982 requested_transition == catatonia) { 1983 /* 1984 * /etc/rc.shutdown executed /sbin/reboot; 1985 * wait for the end quietly 1986 */ 1987 sigset_t s; 1988 1989 sigfillset(&s); 1990 for (;;) 1991 sigsuspend(&s); 1992 } 1993 1994 if (!WIFEXITED(status)) { 1995 warning("%s on %s terminated abnormally, going to " 1996 "single user mode", shell, _PATH_RUNDOWN); 1997 return -2; 1998 } 1999 2000 if ((status = WEXITSTATUS(status)) != 0) 2001 warning("%s returned status %d", _PATH_RUNDOWN, status); 2002 2003 return status; 2004 } 2005 2006 static char * 2007 strk(char *p) 2008 { 2009 static char *t; 2010 char *q; 2011 int c; 2012 2013 if (p) 2014 t = p; 2015 if (!t) 2016 return 0; 2017 2018 c = *t; 2019 while (c == ' ' || c == '\t' ) 2020 c = *++t; 2021 if (!c) { 2022 t = 0; 2023 return 0; 2024 } 2025 q = t; 2026 if (c == '\'') { 2027 c = *++t; 2028 q = t; 2029 while (c && c != '\'') 2030 c = *++t; 2031 if (!c) /* unterminated string */ 2032 q = t = 0; 2033 else 2034 *t++ = 0; 2035 } else { 2036 while (c && c != ' ' && c != '\t' ) 2037 c = *++t; 2038 *t++ = 0; 2039 if (!c) 2040 t = 0; 2041 } 2042 return q; 2043 } 2044 2045 #ifdef LOGIN_CAP 2046 static void 2047 setprocresources(const char *cname) 2048 { 2049 login_cap_t *lc; 2050 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 2051 setusercontext(lc, (struct passwd*)NULL, 0, 2052 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2053 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2054 login_close(lc); 2055 } 2056 } 2057 #endif 2058