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 execute_script(char *argv[]); 150 static void open_console(void); 151 static const char *get_shell(void); 152 static void replace_init(char *path); 153 static void write_stderr(const char *message); 154 155 typedef struct init_session { 156 pid_t se_process; /* controlling process */ 157 time_t se_started; /* used to avoid thrashing */ 158 int se_flags; /* status of session */ 159 #define SE_SHUTDOWN 0x1 /* session won't be restarted */ 160 #define SE_PRESENT 0x2 /* session is in /etc/ttys */ 161 #define SE_IFEXISTS 0x4 /* session defined as "onifexists" */ 162 #define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */ 163 int se_nspace; /* spacing count */ 164 char *se_device; /* filename of port */ 165 char *se_getty; /* what to run on that port */ 166 char *se_getty_argv_space; /* pre-parsed argument array space */ 167 char **se_getty_argv; /* pre-parsed argument array */ 168 char *se_window; /* window system (started only once) */ 169 char *se_window_argv_space; /* pre-parsed argument array space */ 170 char **se_window_argv; /* pre-parsed argument array */ 171 char *se_type; /* default terminal type */ 172 struct init_session *se_prev; 173 struct init_session *se_next; 174 } session_t; 175 176 static void free_session(session_t *); 177 static session_t *new_session(session_t *, struct ttyent *); 178 static session_t *sessions; 179 180 static char **construct_argv(char *); 181 static void start_window_system(session_t *); 182 static void collect_child(pid_t); 183 static pid_t start_getty(session_t *); 184 static void transition_handler(int); 185 static void alrm_handler(int); 186 static void setsecuritylevel(int); 187 static int getsecuritylevel(void); 188 static int setupargv(session_t *, struct ttyent *); 189 #ifdef LOGIN_CAP 190 static void setprocresources(const char *); 191 #endif 192 static int clang; 193 194 static int start_session_db(void); 195 static void add_session(session_t *); 196 static void del_session(session_t *); 197 static session_t *find_session(pid_t); 198 static DB *session_db; 199 200 /* 201 * The mother of all processes. 202 */ 203 int 204 main(int argc, char *argv[]) 205 { 206 state_t initial_transition = runcom; 207 char kenv_value[PATH_MAX]; 208 int c, error; 209 struct sigaction sa; 210 sigset_t mask; 211 212 /* Dispose of random users. */ 213 if (getuid() != 0) 214 errx(1, "%s", strerror(EPERM)); 215 216 /* System V users like to reexec init. */ 217 if (getpid() != 1) { 218 #ifdef COMPAT_SYSV_INIT 219 /* So give them what they want */ 220 if (argc > 1) { 221 if (strlen(argv[1]) == 1) { 222 char runlevel = *argv[1]; 223 int sig; 224 225 switch (runlevel) { 226 case '0': /* halt + poweroff */ 227 sig = SIGUSR2; 228 break; 229 case '1': /* single-user */ 230 sig = SIGTERM; 231 break; 232 case '6': /* reboot */ 233 sig = SIGINT; 234 break; 235 case 'c': /* block further logins */ 236 sig = SIGTSTP; 237 break; 238 case 'q': /* rescan /etc/ttys */ 239 sig = SIGHUP; 240 break; 241 case 'r': /* remount root */ 242 sig = SIGEMT; 243 break; 244 default: 245 goto invalid; 246 } 247 kill(1, sig); 248 _exit(0); 249 } else 250 invalid: 251 errx(1, "invalid run-level ``%s''", argv[1]); 252 } else 253 #endif 254 errx(1, "already running"); 255 } 256 257 init_path_argv0 = strdup(argv[0]); 258 if (init_path_argv0 == NULL) 259 err(1, "strdup"); 260 261 /* 262 * Note that this does NOT open a file... 263 * Does 'init' deserve its own facility number? 264 */ 265 openlog("init", LOG_CONS, LOG_AUTH); 266 267 /* 268 * Create an initial session. 269 */ 270 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 271 warning("initial setsid() failed: %m"); 272 273 /* 274 * Establish an initial user so that programs running 275 * single user do not freak out and die (like passwd). 276 */ 277 if (setlogin("root") < 0) 278 warning("setlogin() failed: %m"); 279 280 /* 281 * This code assumes that we always get arguments through flags, 282 * never through bits set in some random machine register. 283 */ 284 while ((c = getopt(argc, argv, "dsfr")) != -1) 285 switch (c) { 286 case 'd': 287 devfs = 1; 288 break; 289 case 's': 290 initial_transition = single_user; 291 break; 292 case 'f': 293 runcom_mode = FASTBOOT; 294 break; 295 case 'r': 296 initial_transition = reroot_phase_two; 297 break; 298 default: 299 warning("unrecognized flag '-%c'", c); 300 break; 301 } 302 303 if (optind != argc) 304 warning("ignoring excess arguments"); 305 306 /* 307 * We catch or block signals rather than ignore them, 308 * so that they get reset on exec. 309 */ 310 handle(badsys, SIGSYS, 0); 311 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 312 SIGXFSZ, 0); 313 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 314 SIGUSR1, SIGUSR2, SIGWINCH, 0); 315 handle(alrm_handler, SIGALRM, 0); 316 sigfillset(&mask); 317 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 318 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 319 SIGALRM, SIGUSR1, SIGUSR2, SIGWINCH, 0); 320 sigprocmask(SIG_SETMASK, &mask, NULL); 321 sigemptyset(&sa.sa_mask); 322 sa.sa_flags = 0; 323 sa.sa_handler = SIG_IGN; 324 sigaction(SIGTTIN, &sa, NULL); 325 sigaction(SIGTTOU, &sa, NULL); 326 327 /* 328 * Paranoia. 329 */ 330 close(0); 331 close(1); 332 close(2); 333 334 if (kenv(KENV_GET, "init_exec", kenv_value, sizeof(kenv_value)) > 0) { 335 replace_init(kenv_value); 336 _exit(0); /* reboot */ 337 } 338 339 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 340 state_func_t next_transition; 341 342 if ((next_transition = run_script(kenv_value)) != NULL) 343 initial_transition = (state_t) next_transition; 344 } 345 346 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 347 if (chdir(kenv_value) != 0 || chroot(".") != 0) 348 warning("Can't chroot to %s: %m", kenv_value); 349 } 350 351 /* 352 * Additional check if devfs needs to be mounted: 353 * If "/" and "/dev" have the same device number, 354 * then it hasn't been mounted yet. 355 */ 356 if (!devfs) { 357 struct stat stst; 358 dev_t root_devno; 359 360 stat("/", &stst); 361 root_devno = stst.st_dev; 362 if (stat("/dev", &stst) != 0) 363 warning("Can't stat /dev: %m"); 364 else if (stst.st_dev == root_devno) 365 devfs++; 366 } 367 368 if (devfs) { 369 struct iovec iov[4]; 370 char *s; 371 int i; 372 373 char _fstype[] = "fstype"; 374 char _devfs[] = "devfs"; 375 char _fspath[] = "fspath"; 376 char _path_dev[]= _PATH_DEV; 377 378 iov[0].iov_base = _fstype; 379 iov[0].iov_len = sizeof(_fstype); 380 iov[1].iov_base = _devfs; 381 iov[1].iov_len = sizeof(_devfs); 382 iov[2].iov_base = _fspath; 383 iov[2].iov_len = sizeof(_fspath); 384 /* 385 * Try to avoid the trailing slash in _PATH_DEV. 386 * Be *very* defensive. 387 */ 388 s = strdup(_PATH_DEV); 389 if (s != NULL) { 390 i = strlen(s); 391 if (i > 0 && s[i - 1] == '/') 392 s[i - 1] = '\0'; 393 iov[3].iov_base = s; 394 iov[3].iov_len = strlen(s) + 1; 395 } else { 396 iov[3].iov_base = _path_dev; 397 iov[3].iov_len = sizeof(_path_dev); 398 } 399 nmount(iov, 4, 0); 400 if (s != NULL) 401 free(s); 402 } 403 404 if (initial_transition != reroot_phase_two) { 405 /* 406 * Unmount reroot leftovers. This runs after init(8) 407 * gets reexecuted after reroot_phase_two() is done. 408 */ 409 error = unmount(_PATH_REROOT, MNT_FORCE); 410 if (error != 0 && errno != EINVAL) 411 warning("Cannot unmount %s: %m", _PATH_REROOT); 412 } 413 414 /* 415 * Start the state machine. 416 */ 417 transition(initial_transition); 418 419 /* 420 * Should never reach here. 421 */ 422 return 1; 423 } 424 425 /* 426 * Associate a function with a signal handler. 427 */ 428 static void 429 handle(sig_t handler, ...) 430 { 431 int sig; 432 struct sigaction sa; 433 sigset_t mask_everything; 434 va_list ap; 435 va_start(ap, handler); 436 437 sa.sa_handler = handler; 438 sigfillset(&mask_everything); 439 440 while ((sig = va_arg(ap, int)) != 0) { 441 sa.sa_mask = mask_everything; 442 /* XXX SA_RESTART? */ 443 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 444 sigaction(sig, &sa, NULL); 445 } 446 va_end(ap); 447 } 448 449 /* 450 * Delete a set of signals from a mask. 451 */ 452 static void 453 delset(sigset_t *maskp, ...) 454 { 455 int sig; 456 va_list ap; 457 va_start(ap, maskp); 458 459 while ((sig = va_arg(ap, int)) != 0) 460 sigdelset(maskp, sig); 461 va_end(ap); 462 } 463 464 /* 465 * Log a message and sleep for a while (to give someone an opportunity 466 * to read it and to save log or hardcopy output if the problem is chronic). 467 * NB: should send a message to the session logger to avoid blocking. 468 */ 469 static void 470 stall(const char *message, ...) 471 { 472 va_list ap; 473 va_start(ap, message); 474 475 vsyslog(LOG_ALERT, message, ap); 476 va_end(ap); 477 sleep(STALL_TIMEOUT); 478 } 479 480 /* 481 * Like stall(), but doesn't sleep. 482 * If cpp had variadic macros, the two functions could be #defines for another. 483 * NB: should send a message to the session logger to avoid blocking. 484 */ 485 static void 486 warning(const char *message, ...) 487 { 488 va_list ap; 489 va_start(ap, message); 490 491 vsyslog(LOG_ALERT, message, ap); 492 va_end(ap); 493 } 494 495 /* 496 * Log an emergency message. 497 * NB: should send a message to the session logger to avoid blocking. 498 */ 499 static void 500 emergency(const char *message, ...) 501 { 502 va_list ap; 503 va_start(ap, message); 504 505 vsyslog(LOG_EMERG, message, ap); 506 va_end(ap); 507 } 508 509 /* 510 * Catch a SIGSYS signal. 511 * 512 * These may arise if a system does not support sysctl. 513 * We tolerate up to 25 of these, then throw in the towel. 514 */ 515 static void 516 badsys(int sig) 517 { 518 static int badcount = 0; 519 520 if (badcount++ < 25) 521 return; 522 disaster(sig); 523 } 524 525 /* 526 * Catch an unexpected signal. 527 */ 528 static void 529 disaster(int sig) 530 { 531 532 emergency("fatal signal: %s", 533 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 534 535 sleep(STALL_TIMEOUT); 536 _exit(sig); /* reboot */ 537 } 538 539 /* 540 * Get the security level of the kernel. 541 */ 542 static int 543 getsecuritylevel(void) 544 { 545 #ifdef KERN_SECURELVL 546 int name[2], curlevel; 547 size_t len; 548 549 name[0] = CTL_KERN; 550 name[1] = KERN_SECURELVL; 551 len = sizeof curlevel; 552 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 553 emergency("cannot get kernel security level: %s", 554 strerror(errno)); 555 return (-1); 556 } 557 return (curlevel); 558 #else 559 return (-1); 560 #endif 561 } 562 563 /* 564 * Set the security level of the kernel. 565 */ 566 static void 567 setsecuritylevel(int newlevel) 568 { 569 #ifdef KERN_SECURELVL 570 int name[2], curlevel; 571 572 curlevel = getsecuritylevel(); 573 if (newlevel == curlevel) 574 return; 575 name[0] = CTL_KERN; 576 name[1] = KERN_SECURELVL; 577 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 578 emergency( 579 "cannot change kernel security level from %d to %d: %s", 580 curlevel, newlevel, strerror(errno)); 581 return; 582 } 583 #ifdef SECURE 584 warning("kernel security level changed from %d to %d", 585 curlevel, newlevel); 586 #endif 587 #endif 588 } 589 590 /* 591 * Change states in the finite state machine. 592 * The initial state is passed as an argument. 593 */ 594 static void 595 transition(state_t s) 596 { 597 598 current_state = s; 599 for (;;) 600 current_state = (state_t) (*current_state)(); 601 } 602 603 /* 604 * Start a session and allocate a controlling terminal. 605 * Only called by children of init after forking. 606 */ 607 static void 608 open_console(void) 609 { 610 int fd; 611 612 /* 613 * Try to open /dev/console. Open the device with O_NONBLOCK to 614 * prevent potential blocking on a carrier. 615 */ 616 revoke(_PATH_CONSOLE); 617 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 618 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 619 if (login_tty(fd) == 0) 620 return; 621 close(fd); 622 } 623 624 /* No luck. Log output to file if possible. */ 625 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 626 stall("cannot open null device."); 627 _exit(1); 628 } 629 if (fd != STDIN_FILENO) { 630 dup2(fd, STDIN_FILENO); 631 close(fd); 632 } 633 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 634 if (fd == -1) 635 dup2(STDIN_FILENO, STDOUT_FILENO); 636 else if (fd != STDOUT_FILENO) { 637 dup2(fd, STDOUT_FILENO); 638 close(fd); 639 } 640 dup2(STDOUT_FILENO, STDERR_FILENO); 641 } 642 643 static const char * 644 get_shell(void) 645 { 646 static char kenv_value[PATH_MAX]; 647 648 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 649 return kenv_value; 650 else 651 return _PATH_BSHELL; 652 } 653 654 static void 655 write_stderr(const char *message) 656 { 657 658 write(STDERR_FILENO, message, strlen(message)); 659 } 660 661 static int 662 read_file(const char *path, void **bufp, size_t *bufsizep) 663 { 664 struct stat sb; 665 size_t bufsize; 666 void *buf; 667 ssize_t nbytes; 668 int error, fd; 669 670 fd = open(path, O_RDONLY); 671 if (fd < 0) { 672 emergency("%s: %s", path, strerror(errno)); 673 return (-1); 674 } 675 676 error = fstat(fd, &sb); 677 if (error != 0) { 678 emergency("fstat: %s", strerror(errno)); 679 close(fd); 680 return (error); 681 } 682 683 bufsize = sb.st_size; 684 buf = malloc(bufsize); 685 if (buf == NULL) { 686 emergency("malloc: %s", strerror(errno)); 687 close(fd); 688 return (error); 689 } 690 691 nbytes = read(fd, buf, bufsize); 692 if (nbytes != (ssize_t)bufsize) { 693 emergency("read: %s", strerror(errno)); 694 close(fd); 695 free(buf); 696 return (error); 697 } 698 699 error = close(fd); 700 if (error != 0) { 701 emergency("close: %s", strerror(errno)); 702 free(buf); 703 return (error); 704 } 705 706 *bufp = buf; 707 *bufsizep = bufsize; 708 709 return (0); 710 } 711 712 static int 713 create_file(const char *path, const void *buf, size_t bufsize) 714 { 715 ssize_t nbytes; 716 int error, fd; 717 718 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 719 if (fd < 0) { 720 emergency("%s: %s", path, strerror(errno)); 721 return (-1); 722 } 723 724 nbytes = write(fd, buf, bufsize); 725 if (nbytes != (ssize_t)bufsize) { 726 emergency("write: %s", strerror(errno)); 727 close(fd); 728 return (-1); 729 } 730 731 error = close(fd); 732 if (error != 0) { 733 emergency("close: %s", strerror(errno)); 734 return (-1); 735 } 736 737 return (0); 738 } 739 740 static int 741 mount_tmpfs(const char *fspath) 742 { 743 struct iovec *iov; 744 char errmsg[255]; 745 int error, iovlen; 746 747 iov = NULL; 748 iovlen = 0; 749 memset(errmsg, 0, sizeof(errmsg)); 750 build_iovec(&iov, &iovlen, "fstype", 751 __DECONST(void *, "tmpfs"), (size_t)-1); 752 build_iovec(&iov, &iovlen, "fspath", 753 __DECONST(void *, fspath), (size_t)-1); 754 build_iovec(&iov, &iovlen, "errmsg", 755 errmsg, sizeof(errmsg)); 756 757 error = nmount(iov, iovlen, 0); 758 if (error != 0) { 759 if (*errmsg != '\0') { 760 emergency("cannot mount tmpfs on %s: %s: %s", 761 fspath, errmsg, strerror(errno)); 762 } else { 763 emergency("cannot mount tmpfs on %s: %s", 764 fspath, strerror(errno)); 765 } 766 return (error); 767 } 768 return (0); 769 } 770 771 static state_func_t 772 reroot(void) 773 { 774 void *buf; 775 size_t bufsize; 776 int error; 777 778 buf = NULL; 779 bufsize = 0; 780 781 revoke_ttys(); 782 runshutdown(); 783 784 /* 785 * Make sure nobody can interfere with our scheme. 786 * Ignore ESRCH, which can apparently happen when 787 * there are no processes to kill. 788 */ 789 error = kill(-1, SIGKILL); 790 if (error != 0 && errno != ESRCH) { 791 emergency("kill(2) failed: %s", strerror(errno)); 792 goto out; 793 } 794 795 /* 796 * Copy the init binary into tmpfs, so that we can unmount 797 * the old rootfs without committing suicide. 798 */ 799 error = read_file(init_path_argv0, &buf, &bufsize); 800 if (error != 0) 801 goto out; 802 error = mount_tmpfs(_PATH_REROOT); 803 if (error != 0) 804 goto out; 805 error = create_file(_PATH_REROOT_INIT, buf, bufsize); 806 if (error != 0) 807 goto out; 808 809 /* 810 * Execute the temporary init. 811 */ 812 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); 813 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno)); 814 815 out: 816 emergency("reroot failed; going to single user mode"); 817 free(buf); 818 return (state_func_t) single_user; 819 } 820 821 static state_func_t 822 reroot_phase_two(void) 823 { 824 char init_path[PATH_MAX], *path, *path_component; 825 size_t init_path_len; 826 int nbytes, error; 827 828 /* 829 * Ask the kernel to mount the new rootfs. 830 */ 831 error = reboot(RB_REROOT); 832 if (error != 0) { 833 emergency("RB_REBOOT failed: %s", strerror(errno)); 834 goto out; 835 } 836 837 /* 838 * Figure out where the destination init(8) binary is. Note that 839 * the path could be different than what we've started with. Use 840 * the value from kenv, if set, or the one from sysctl otherwise. 841 * The latter defaults to a hardcoded value, but can be overridden 842 * by a build time option. 843 */ 844 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 845 if (nbytes <= 0) { 846 init_path_len = sizeof(init_path); 847 error = sysctlbyname("kern.init_path", 848 init_path, &init_path_len, NULL, 0); 849 if (error != 0) { 850 emergency("failed to retrieve kern.init_path: %s", 851 strerror(errno)); 852 goto out; 853 } 854 } 855 856 /* 857 * Repeat the init search logic from sys/kern/init_path.c 858 */ 859 path_component = init_path; 860 while ((path = strsep(&path_component, ":")) != NULL) { 861 /* 862 * Execute init(8) from the new rootfs. 863 */ 864 execl(path, path, NULL); 865 } 866 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 867 868 out: 869 emergency("reroot failed; going to single user mode"); 870 return (state_func_t) single_user; 871 } 872 873 /* 874 * Bring the system up single user. 875 */ 876 static state_func_t 877 single_user(void) 878 { 879 pid_t pid, wpid; 880 int status; 881 sigset_t mask; 882 const char *shell; 883 char *argv[2]; 884 struct timeval tv, tn; 885 #ifdef SECURE 886 struct ttyent *typ; 887 struct passwd *pp; 888 static const char banner[] = 889 "Enter root password, or ^D to go multi-user\n"; 890 char *clear, *password; 891 #endif 892 #ifdef DEBUGSHELL 893 char altshell[128]; 894 #endif 895 896 if (Reboot) { 897 /* Instead of going single user, let's reboot the machine */ 898 sync(); 899 if (reboot(howto) == -1) { 900 emergency("reboot(%#x) failed, %s", howto, 901 strerror(errno)); 902 _exit(1); /* panic and reboot */ 903 } 904 warning("reboot(%#x) returned", howto); 905 _exit(0); /* panic as well */ 906 } 907 908 shell = get_shell(); 909 910 if ((pid = fork()) == 0) { 911 /* 912 * Start the single user session. 913 */ 914 open_console(); 915 916 #ifdef SECURE 917 /* 918 * Check the root password. 919 * We don't care if the console is 'on' by default; 920 * it's the only tty that can be 'off' and 'secure'. 921 */ 922 typ = getttynam("console"); 923 pp = getpwnam("root"); 924 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 925 pp && *pp->pw_passwd) { 926 write_stderr(banner); 927 for (;;) { 928 clear = getpass("Password:"); 929 if (clear == NULL || *clear == '\0') 930 _exit(0); 931 password = crypt(clear, pp->pw_passwd); 932 bzero(clear, _PASSWORD_LEN); 933 if (password != NULL && 934 strcmp(password, pp->pw_passwd) == 0) 935 break; 936 warning("single-user login failed\n"); 937 } 938 } 939 endttyent(); 940 endpwent(); 941 #endif /* SECURE */ 942 943 #ifdef DEBUGSHELL 944 { 945 char *cp = altshell; 946 int num; 947 948 #define SHREQUEST "Enter full pathname of shell or RETURN for " 949 write_stderr(SHREQUEST); 950 write_stderr(shell); 951 write_stderr(": "); 952 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 953 num != 0 && *cp != '\n' && cp < &altshell[127]) 954 cp++; 955 *cp = '\0'; 956 if (altshell[0] != '\0') 957 shell = altshell; 958 } 959 #endif /* DEBUGSHELL */ 960 961 /* 962 * Unblock signals. 963 * We catch all the interesting ones, 964 * and those are reset to SIG_DFL on exec. 965 */ 966 sigemptyset(&mask); 967 sigprocmask(SIG_SETMASK, &mask, NULL); 968 969 /* 970 * Fire off a shell. 971 * If the default one doesn't work, try the Bourne shell. 972 */ 973 974 char name[] = "-sh"; 975 976 argv[0] = name; 977 argv[1] = NULL; 978 execv(shell, argv); 979 emergency("can't exec %s for single user: %m", shell); 980 execv(_PATH_BSHELL, argv); 981 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 982 sleep(STALL_TIMEOUT); 983 _exit(1); 984 } 985 986 if (pid == -1) { 987 /* 988 * We are seriously hosed. Do our best. 989 */ 990 emergency("can't fork single-user shell, trying again"); 991 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 992 continue; 993 return (state_func_t) single_user; 994 } 995 996 requested_transition = 0; 997 do { 998 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 999 collect_child(wpid); 1000 if (wpid == -1) { 1001 if (errno == EINTR) 1002 continue; 1003 warning("wait for single-user shell failed: %m; restarting"); 1004 return (state_func_t) single_user; 1005 } 1006 if (wpid == pid && WIFSTOPPED(status)) { 1007 warning("init: shell stopped, restarting\n"); 1008 kill(pid, SIGCONT); 1009 wpid = -1; 1010 } 1011 } while (wpid != pid && !requested_transition); 1012 1013 if (requested_transition) 1014 return (state_func_t) requested_transition; 1015 1016 if (!WIFEXITED(status)) { 1017 if (WTERMSIG(status) == SIGKILL) { 1018 /* 1019 * reboot(8) killed shell? 1020 */ 1021 warning("single user shell terminated."); 1022 gettimeofday(&tv, NULL); 1023 tn = tv; 1024 tv.tv_sec += STALL_TIMEOUT; 1025 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == 1026 tn.tv_sec && tv.tv_usec > tn.tv_usec)) { 1027 sleep(1); 1028 gettimeofday(&tn, NULL); 1029 } 1030 _exit(0); 1031 } else { 1032 warning("single user shell terminated, restarting"); 1033 return (state_func_t) single_user; 1034 } 1035 } 1036 1037 runcom_mode = FASTBOOT; 1038 return (state_func_t) runcom; 1039 } 1040 1041 /* 1042 * Run the system startup script. 1043 */ 1044 static state_func_t 1045 runcom(void) 1046 { 1047 state_func_t next_transition; 1048 1049 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL) 1050 return next_transition; 1051 1052 runcom_mode = AUTOBOOT; /* the default */ 1053 return (state_func_t) read_ttys; 1054 } 1055 1056 static void 1057 execute_script(char *argv[]) 1058 { 1059 struct sigaction sa; 1060 const char *shell, *script; 1061 int error; 1062 1063 bzero(&sa, sizeof(sa)); 1064 sigemptyset(&sa.sa_mask); 1065 sa.sa_handler = SIG_IGN; 1066 sigaction(SIGTSTP, &sa, NULL); 1067 sigaction(SIGHUP, &sa, NULL); 1068 1069 open_console(); 1070 1071 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL); 1072 #ifdef LOGIN_CAP 1073 setprocresources(RESOURCE_RC); 1074 #endif 1075 1076 /* 1077 * Try to directly execute the script first. If it 1078 * fails, try the old method of passing the script path 1079 * to sh(1). Don't complain if it fails because of 1080 * the missing execute bit. 1081 */ 1082 script = argv[1]; 1083 error = access(script, X_OK); 1084 if (error == 0) { 1085 execv(script, argv + 1); 1086 warning("can't exec %s: %m", script); 1087 } else if (errno != EACCES) { 1088 warning("can't access %s: %m", script); 1089 } 1090 1091 shell = get_shell(); 1092 execv(shell, argv); 1093 stall("can't exec %s for %s: %m", shell, script); 1094 } 1095 1096 /* 1097 * Execute binary, replacing init(8) as PID 1. 1098 */ 1099 static void 1100 replace_init(char *path) 1101 { 1102 char *argv[3]; 1103 char sh[] = "sh"; 1104 1105 argv[0] = sh; 1106 argv[1] = path; 1107 argv[2] = NULL; 1108 1109 execute_script(argv); 1110 } 1111 1112 /* 1113 * Run a shell script. 1114 * Returns 0 on success, otherwise the next transition to enter: 1115 * - single_user if fork/execv/waitpid failed, or if the script 1116 * terminated with a signal or exit code != 0. 1117 * - death_single if a SIGTERM was delivered to init(8). 1118 */ 1119 static state_func_t 1120 run_script(const char *script) 1121 { 1122 pid_t pid, wpid; 1123 int status; 1124 char *argv[4]; 1125 const char *shell; 1126 1127 shell = get_shell(); 1128 1129 if ((pid = fork()) == 0) { 1130 1131 char _sh[] = "sh"; 1132 char _autoboot[] = "autoboot"; 1133 1134 argv[0] = _sh; 1135 argv[1] = __DECONST(char *, script); 1136 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1137 argv[3] = NULL; 1138 1139 execute_script(argv); 1140 sleep(STALL_TIMEOUT); 1141 _exit(1); /* force single user mode */ 1142 } 1143 1144 if (pid == -1) { 1145 emergency("can't fork for %s on %s: %m", shell, script); 1146 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1147 continue; 1148 sleep(STALL_TIMEOUT); 1149 return (state_func_t) single_user; 1150 } 1151 1152 /* 1153 * Copied from single_user(). This is a bit paranoid. 1154 */ 1155 requested_transition = 0; 1156 do { 1157 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1158 collect_child(wpid); 1159 if (wpid == -1) { 1160 if (requested_transition == death_single || 1161 requested_transition == reroot) 1162 return (state_func_t) requested_transition; 1163 if (errno == EINTR) 1164 continue; 1165 warning("wait for %s on %s failed: %m; going to " 1166 "single user mode", shell, script); 1167 return (state_func_t) single_user; 1168 } 1169 if (wpid == pid && WIFSTOPPED(status)) { 1170 warning("init: %s on %s stopped, restarting\n", 1171 shell, script); 1172 kill(pid, SIGCONT); 1173 wpid = -1; 1174 } 1175 } while (wpid != pid); 1176 1177 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1178 requested_transition == catatonia) { 1179 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1180 sigset_t s; 1181 1182 sigfillset(&s); 1183 for (;;) 1184 sigsuspend(&s); 1185 } 1186 1187 if (!WIFEXITED(status)) { 1188 warning("%s on %s terminated abnormally, going to single " 1189 "user mode", shell, script); 1190 return (state_func_t) single_user; 1191 } 1192 1193 if (WEXITSTATUS(status)) 1194 return (state_func_t) single_user; 1195 1196 return (state_func_t) 0; 1197 } 1198 1199 /* 1200 * Open the session database. 1201 * 1202 * NB: We could pass in the size here; is it necessary? 1203 */ 1204 static int 1205 start_session_db(void) 1206 { 1207 if (session_db && (*session_db->close)(session_db)) 1208 emergency("session database close: %s", strerror(errno)); 1209 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 1210 emergency("session database open: %s", strerror(errno)); 1211 return (1); 1212 } 1213 return (0); 1214 1215 } 1216 1217 /* 1218 * Add a new login session. 1219 */ 1220 static void 1221 add_session(session_t *sp) 1222 { 1223 DBT key; 1224 DBT data; 1225 1226 key.data = &sp->se_process; 1227 key.size = sizeof sp->se_process; 1228 data.data = &sp; 1229 data.size = sizeof sp; 1230 1231 if ((*session_db->put)(session_db, &key, &data, 0)) 1232 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1233 } 1234 1235 /* 1236 * Delete an old login session. 1237 */ 1238 static void 1239 del_session(session_t *sp) 1240 { 1241 DBT key; 1242 1243 key.data = &sp->se_process; 1244 key.size = sizeof sp->se_process; 1245 1246 if ((*session_db->del)(session_db, &key, 0)) 1247 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1248 } 1249 1250 /* 1251 * Look up a login session by pid. 1252 */ 1253 static session_t * 1254 find_session(pid_t pid) 1255 { 1256 DBT key; 1257 DBT data; 1258 session_t *ret; 1259 1260 key.data = &pid; 1261 key.size = sizeof pid; 1262 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1263 return 0; 1264 bcopy(data.data, (char *)&ret, sizeof(ret)); 1265 return ret; 1266 } 1267 1268 /* 1269 * Construct an argument vector from a command line. 1270 */ 1271 static char ** 1272 construct_argv(char *command) 1273 { 1274 int argc = 0; 1275 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1276 * sizeof (char *)); 1277 1278 if ((argv[argc++] = strk(command)) == NULL) { 1279 free(argv); 1280 return (NULL); 1281 } 1282 while ((argv[argc++] = strk((char *) 0)) != NULL) 1283 continue; 1284 return argv; 1285 } 1286 1287 /* 1288 * Deallocate a session descriptor. 1289 */ 1290 static void 1291 free_session(session_t *sp) 1292 { 1293 free(sp->se_device); 1294 if (sp->se_getty) { 1295 free(sp->se_getty); 1296 free(sp->se_getty_argv_space); 1297 free(sp->se_getty_argv); 1298 } 1299 if (sp->se_window) { 1300 free(sp->se_window); 1301 free(sp->se_window_argv_space); 1302 free(sp->se_window_argv); 1303 } 1304 if (sp->se_type) 1305 free(sp->se_type); 1306 free(sp); 1307 } 1308 1309 /* 1310 * Allocate a new session descriptor. 1311 * Mark it SE_PRESENT. 1312 */ 1313 static session_t * 1314 new_session(session_t *sprev, struct ttyent *typ) 1315 { 1316 session_t *sp; 1317 1318 if ((typ->ty_status & TTY_ON) == 0 || 1319 typ->ty_name == 0 || 1320 typ->ty_getty == 0) 1321 return 0; 1322 1323 sp = (session_t *) calloc(1, sizeof (session_t)); 1324 1325 sp->se_flags |= SE_PRESENT; 1326 1327 if ((typ->ty_status & TTY_IFEXISTS) != 0) 1328 sp->se_flags |= SE_IFEXISTS; 1329 1330 if ((typ->ty_status & TTY_IFCONSOLE) != 0) 1331 sp->se_flags |= SE_IFCONSOLE; 1332 1333 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0) 1334 err(1, "asprintf"); 1335 1336 if (setupargv(sp, typ) == 0) { 1337 free_session(sp); 1338 return (0); 1339 } 1340 1341 sp->se_next = 0; 1342 if (sprev == NULL) { 1343 sessions = sp; 1344 sp->se_prev = 0; 1345 } else { 1346 sprev->se_next = sp; 1347 sp->se_prev = sprev; 1348 } 1349 1350 return sp; 1351 } 1352 1353 /* 1354 * Calculate getty and if useful window argv vectors. 1355 */ 1356 static int 1357 setupargv(session_t *sp, struct ttyent *typ) 1358 { 1359 1360 if (sp->se_getty) { 1361 free(sp->se_getty); 1362 free(sp->se_getty_argv_space); 1363 free(sp->se_getty_argv); 1364 } 1365 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0) 1366 err(1, "asprintf"); 1367 sp->se_getty_argv_space = strdup(sp->se_getty); 1368 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1369 if (sp->se_getty_argv == NULL) { 1370 warning("can't parse getty for port %s", sp->se_device); 1371 free(sp->se_getty); 1372 free(sp->se_getty_argv_space); 1373 sp->se_getty = sp->se_getty_argv_space = 0; 1374 return (0); 1375 } 1376 if (sp->se_window) { 1377 free(sp->se_window); 1378 free(sp->se_window_argv_space); 1379 free(sp->se_window_argv); 1380 } 1381 sp->se_window = sp->se_window_argv_space = 0; 1382 sp->se_window_argv = 0; 1383 if (typ->ty_window) { 1384 sp->se_window = strdup(typ->ty_window); 1385 sp->se_window_argv_space = strdup(sp->se_window); 1386 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1387 if (sp->se_window_argv == NULL) { 1388 warning("can't parse window for port %s", 1389 sp->se_device); 1390 free(sp->se_window_argv_space); 1391 free(sp->se_window); 1392 sp->se_window = sp->se_window_argv_space = 0; 1393 return (0); 1394 } 1395 } 1396 if (sp->se_type) 1397 free(sp->se_type); 1398 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1399 return (1); 1400 } 1401 1402 /* 1403 * Walk the list of ttys and create sessions for each active line. 1404 */ 1405 static state_func_t 1406 read_ttys(void) 1407 { 1408 session_t *sp, *snext; 1409 struct ttyent *typ; 1410 1411 /* 1412 * Destroy any previous session state. 1413 * There shouldn't be any, but just in case... 1414 */ 1415 for (sp = sessions; sp; sp = snext) { 1416 snext = sp->se_next; 1417 free_session(sp); 1418 } 1419 sessions = 0; 1420 if (start_session_db()) 1421 return (state_func_t) single_user; 1422 1423 /* 1424 * Allocate a session entry for each active port. 1425 * Note that sp starts at 0. 1426 */ 1427 while ((typ = getttyent()) != NULL) 1428 if ((snext = new_session(sp, typ)) != NULL) 1429 sp = snext; 1430 1431 endttyent(); 1432 1433 return (state_func_t) multi_user; 1434 } 1435 1436 /* 1437 * Start a window system running. 1438 */ 1439 static void 1440 start_window_system(session_t *sp) 1441 { 1442 pid_t pid; 1443 sigset_t mask; 1444 char term[64], *env[2]; 1445 int status; 1446 1447 if ((pid = fork()) == -1) { 1448 emergency("can't fork for window system on port %s: %m", 1449 sp->se_device); 1450 /* hope that getty fails and we can try again */ 1451 return; 1452 } 1453 if (pid) { 1454 waitpid(-1, &status, 0); 1455 return; 1456 } 1457 1458 /* reparent window process to the init to not make a zombie on exit */ 1459 if ((pid = fork()) == -1) { 1460 emergency("can't fork for window system on port %s: %m", 1461 sp->se_device); 1462 _exit(1); 1463 } 1464 if (pid) 1465 _exit(0); 1466 1467 sigemptyset(&mask); 1468 sigprocmask(SIG_SETMASK, &mask, NULL); 1469 1470 if (setsid() < 0) 1471 emergency("setsid failed (window) %m"); 1472 1473 #ifdef LOGIN_CAP 1474 setprocresources(RESOURCE_WINDOW); 1475 #endif 1476 if (sp->se_type) { 1477 /* Don't use malloc after fork */ 1478 strcpy(term, "TERM="); 1479 strlcat(term, sp->se_type, sizeof(term)); 1480 env[0] = term; 1481 env[1] = NULL; 1482 } 1483 else 1484 env[0] = NULL; 1485 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1486 stall("can't exec window system '%s' for port %s: %m", 1487 sp->se_window_argv[0], sp->se_device); 1488 _exit(1); 1489 } 1490 1491 /* 1492 * Start a login session running. 1493 */ 1494 static pid_t 1495 start_getty(session_t *sp) 1496 { 1497 pid_t pid; 1498 sigset_t mask; 1499 time_t current_time = time((time_t *) 0); 1500 int too_quick = 0; 1501 char term[64], *env[2]; 1502 1503 if (current_time >= sp->se_started && 1504 current_time - sp->se_started < GETTY_SPACING) { 1505 if (++sp->se_nspace > GETTY_NSPACE) { 1506 sp->se_nspace = 0; 1507 too_quick = 1; 1508 } 1509 } else 1510 sp->se_nspace = 0; 1511 1512 /* 1513 * fork(), not vfork() -- we can't afford to block. 1514 */ 1515 if ((pid = fork()) == -1) { 1516 emergency("can't fork for getty on port %s: %m", sp->se_device); 1517 return -1; 1518 } 1519 1520 if (pid) 1521 return pid; 1522 1523 if (too_quick) { 1524 warning("getty repeating too quickly on port %s, sleeping %d secs", 1525 sp->se_device, GETTY_SLEEP); 1526 sleep((unsigned) GETTY_SLEEP); 1527 } 1528 1529 if (sp->se_window) { 1530 start_window_system(sp); 1531 sleep(WINDOW_WAIT); 1532 } 1533 1534 sigemptyset(&mask); 1535 sigprocmask(SIG_SETMASK, &mask, NULL); 1536 1537 #ifdef LOGIN_CAP 1538 setprocresources(RESOURCE_GETTY); 1539 #endif 1540 if (sp->se_type) { 1541 /* Don't use malloc after fork */ 1542 strcpy(term, "TERM="); 1543 strlcat(term, sp->se_type, sizeof(term)); 1544 env[0] = term; 1545 env[1] = NULL; 1546 } else 1547 env[0] = NULL; 1548 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1549 stall("can't exec getty '%s' for port %s: %m", 1550 sp->se_getty_argv[0], sp->se_device); 1551 _exit(1); 1552 } 1553 1554 /* 1555 * Return 1 if the session is defined as "onifexists" 1556 * or "onifconsole" and the device node does not exist. 1557 */ 1558 static int 1559 session_has_no_tty(session_t *sp) 1560 { 1561 int fd; 1562 1563 if ((sp->se_flags & SE_IFEXISTS) == 0 && 1564 (sp->se_flags & SE_IFCONSOLE) == 0) 1565 return (0); 1566 1567 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0); 1568 if (fd < 0) { 1569 if (errno == ENOENT) 1570 return (1); 1571 return (0); 1572 } 1573 1574 close(fd); 1575 return (0); 1576 } 1577 1578 /* 1579 * Collect exit status for a child. 1580 * If an exiting login, start a new login running. 1581 */ 1582 static void 1583 collect_child(pid_t pid) 1584 { 1585 session_t *sp, *sprev, *snext; 1586 1587 if (! sessions) 1588 return; 1589 1590 if (! (sp = find_session(pid))) 1591 return; 1592 1593 del_session(sp); 1594 sp->se_process = 0; 1595 1596 if (sp->se_flags & SE_SHUTDOWN || 1597 session_has_no_tty(sp)) { 1598 if ((sprev = sp->se_prev) != NULL) 1599 sprev->se_next = sp->se_next; 1600 else 1601 sessions = sp->se_next; 1602 if ((snext = sp->se_next) != NULL) 1603 snext->se_prev = sp->se_prev; 1604 free_session(sp); 1605 return; 1606 } 1607 1608 if ((pid = start_getty(sp)) == -1) { 1609 /* serious trouble */ 1610 requested_transition = clean_ttys; 1611 return; 1612 } 1613 1614 sp->se_process = pid; 1615 sp->se_started = time((time_t *) 0); 1616 add_session(sp); 1617 } 1618 1619 /* 1620 * Catch a signal and request a state transition. 1621 */ 1622 static void 1623 transition_handler(int sig) 1624 { 1625 1626 switch (sig) { 1627 case SIGHUP: 1628 if (current_state == read_ttys || current_state == multi_user || 1629 current_state == clean_ttys || current_state == catatonia) 1630 requested_transition = clean_ttys; 1631 break; 1632 case SIGWINCH: 1633 case SIGUSR2: 1634 howto = sig == SIGUSR2 ? RB_POWEROFF : RB_POWERCYCLE; 1635 case SIGUSR1: 1636 howto |= RB_HALT; 1637 case SIGINT: 1638 Reboot = TRUE; 1639 case SIGTERM: 1640 if (current_state == read_ttys || current_state == multi_user || 1641 current_state == clean_ttys || current_state == catatonia) 1642 requested_transition = death; 1643 else 1644 requested_transition = death_single; 1645 break; 1646 case SIGTSTP: 1647 if (current_state == runcom || current_state == read_ttys || 1648 current_state == clean_ttys || 1649 current_state == multi_user || current_state == catatonia) 1650 requested_transition = catatonia; 1651 break; 1652 case SIGEMT: 1653 requested_transition = reroot; 1654 break; 1655 default: 1656 requested_transition = 0; 1657 break; 1658 } 1659 } 1660 1661 /* 1662 * Take the system multiuser. 1663 */ 1664 static state_func_t 1665 multi_user(void) 1666 { 1667 pid_t pid; 1668 session_t *sp; 1669 1670 requested_transition = 0; 1671 1672 /* 1673 * If the administrator has not set the security level to -1 1674 * to indicate that the kernel should not run multiuser in secure 1675 * mode, and the run script has not set a higher level of security 1676 * than level 1, then put the kernel into secure mode. 1677 */ 1678 if (getsecuritylevel() == 0) 1679 setsecuritylevel(1); 1680 1681 for (sp = sessions; sp; sp = sp->se_next) { 1682 if (sp->se_process) 1683 continue; 1684 if (session_has_no_tty(sp)) 1685 continue; 1686 if ((pid = start_getty(sp)) == -1) { 1687 /* serious trouble */ 1688 requested_transition = clean_ttys; 1689 break; 1690 } 1691 sp->se_process = pid; 1692 sp->se_started = time((time_t *) 0); 1693 add_session(sp); 1694 } 1695 1696 while (!requested_transition) 1697 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1698 collect_child(pid); 1699 1700 return (state_func_t) requested_transition; 1701 } 1702 1703 /* 1704 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1705 */ 1706 static state_func_t 1707 clean_ttys(void) 1708 { 1709 session_t *sp, *sprev; 1710 struct ttyent *typ; 1711 int devlen; 1712 char *old_getty, *old_window, *old_type; 1713 1714 /* 1715 * mark all sessions for death, (!SE_PRESENT) 1716 * as we find or create new ones they'll be marked as keepers, 1717 * we'll later nuke all the ones not found in /etc/ttys 1718 */ 1719 for (sp = sessions; sp != NULL; sp = sp->se_next) 1720 sp->se_flags &= ~SE_PRESENT; 1721 1722 devlen = sizeof(_PATH_DEV) - 1; 1723 while ((typ = getttyent()) != NULL) { 1724 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1725 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1726 break; 1727 1728 if (sp) { 1729 /* we want this one to live */ 1730 sp->se_flags |= SE_PRESENT; 1731 if ((typ->ty_status & TTY_ON) == 0 || 1732 typ->ty_getty == 0) { 1733 sp->se_flags |= SE_SHUTDOWN; 1734 kill(sp->se_process, SIGHUP); 1735 continue; 1736 } 1737 sp->se_flags &= ~SE_SHUTDOWN; 1738 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1739 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1740 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1741 if (setupargv(sp, typ) == 0) { 1742 warning("can't parse getty for port %s", 1743 sp->se_device); 1744 sp->se_flags |= SE_SHUTDOWN; 1745 kill(sp->se_process, SIGHUP); 1746 } 1747 else if ( !old_getty 1748 || (!old_type && sp->se_type) 1749 || (old_type && !sp->se_type) 1750 || (!old_window && sp->se_window) 1751 || (old_window && !sp->se_window) 1752 || (strcmp(old_getty, sp->se_getty) != 0) 1753 || (old_window && strcmp(old_window, sp->se_window) != 0) 1754 || (old_type && strcmp(old_type, sp->se_type) != 0) 1755 ) { 1756 /* Don't set SE_SHUTDOWN here */ 1757 sp->se_nspace = 0; 1758 sp->se_started = 0; 1759 kill(sp->se_process, SIGHUP); 1760 } 1761 if (old_getty) 1762 free(old_getty); 1763 if (old_window) 1764 free(old_window); 1765 if (old_type) 1766 free(old_type); 1767 continue; 1768 } 1769 1770 new_session(sprev, typ); 1771 } 1772 1773 endttyent(); 1774 1775 /* 1776 * sweep through and kill all deleted sessions 1777 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1778 */ 1779 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1780 if ((sp->se_flags & SE_PRESENT) == 0) { 1781 sp->se_flags |= SE_SHUTDOWN; 1782 kill(sp->se_process, SIGHUP); 1783 } 1784 } 1785 1786 return (state_func_t) multi_user; 1787 } 1788 1789 /* 1790 * Block further logins. 1791 */ 1792 static state_func_t 1793 catatonia(void) 1794 { 1795 session_t *sp; 1796 1797 for (sp = sessions; sp; sp = sp->se_next) 1798 sp->se_flags |= SE_SHUTDOWN; 1799 1800 return (state_func_t) multi_user; 1801 } 1802 1803 /* 1804 * Note SIGALRM. 1805 */ 1806 static void 1807 alrm_handler(int sig) 1808 { 1809 1810 (void)sig; 1811 clang = 1; 1812 } 1813 1814 /* 1815 * Bring the system down to single user. 1816 */ 1817 static state_func_t 1818 death(void) 1819 { 1820 int block, blocked; 1821 size_t len; 1822 1823 /* Temporarily block suspend. */ 1824 len = sizeof(blocked); 1825 block = 1; 1826 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1827 &block, sizeof(block)) == -1) 1828 blocked = 0; 1829 1830 /* 1831 * Also revoke the TTY here. Because runshutdown() may reopen 1832 * the TTY whose getty we're killing here, there is no guarantee 1833 * runshutdown() will perform the initial open() call, causing 1834 * the terminal attributes to be misconfigured. 1835 */ 1836 revoke_ttys(); 1837 1838 /* Try to run the rc.shutdown script within a period of time */ 1839 runshutdown(); 1840 1841 /* Unblock suspend if we blocked it. */ 1842 if (!blocked) 1843 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1844 &blocked, sizeof(blocked)); 1845 1846 return (state_func_t) death_single; 1847 } 1848 1849 /* 1850 * Do what is necessary to reinitialize single user mode or reboot 1851 * from an incomplete state. 1852 */ 1853 static state_func_t 1854 death_single(void) 1855 { 1856 int i; 1857 pid_t pid; 1858 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1859 1860 revoke(_PATH_CONSOLE); 1861 1862 for (i = 0; i < 2; ++i) { 1863 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1864 return (state_func_t) single_user; 1865 1866 clang = 0; 1867 alarm(DEATH_WATCH); 1868 do 1869 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1870 collect_child(pid); 1871 while (clang == 0 && errno != ECHILD); 1872 1873 if (errno == ECHILD) 1874 return (state_func_t) single_user; 1875 } 1876 1877 warning("some processes would not die; ps axl advised"); 1878 1879 return (state_func_t) single_user; 1880 } 1881 1882 static void 1883 revoke_ttys(void) 1884 { 1885 session_t *sp; 1886 1887 for (sp = sessions; sp; sp = sp->se_next) { 1888 sp->se_flags |= SE_SHUTDOWN; 1889 kill(sp->se_process, SIGHUP); 1890 revoke(sp->se_device); 1891 } 1892 } 1893 1894 /* 1895 * Run the system shutdown script. 1896 * 1897 * Exit codes: XXX I should document more 1898 * -2 shutdown script terminated abnormally 1899 * -1 fatal error - can't run script 1900 * 0 good. 1901 * >0 some error (exit code) 1902 */ 1903 static int 1904 runshutdown(void) 1905 { 1906 pid_t pid, wpid; 1907 int status; 1908 int shutdowntimeout; 1909 size_t len; 1910 char *argv[4]; 1911 struct stat sb; 1912 1913 /* 1914 * rc.shutdown is optional, so to prevent any unnecessary 1915 * complaints from the shell we simply don't run it if the 1916 * file does not exist. If the stat() here fails for other 1917 * reasons, we'll let the shell complain. 1918 */ 1919 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1920 return 0; 1921 1922 if ((pid = fork()) == 0) { 1923 char _sh[] = "sh"; 1924 char _reboot[] = "reboot"; 1925 char _single[] = "single"; 1926 char _path_rundown[] = _PATH_RUNDOWN; 1927 1928 argv[0] = _sh; 1929 argv[1] = _path_rundown; 1930 argv[2] = Reboot ? _reboot : _single; 1931 argv[3] = NULL; 1932 1933 execute_script(argv); 1934 _exit(1); /* force single user mode */ 1935 } 1936 1937 if (pid == -1) { 1938 emergency("can't fork for %s: %m", _PATH_RUNDOWN); 1939 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1940 continue; 1941 sleep(STALL_TIMEOUT); 1942 return -1; 1943 } 1944 1945 len = sizeof(shutdowntimeout); 1946 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1947 NULL, 0) == -1 || shutdowntimeout < 2) 1948 shutdowntimeout = DEATH_SCRIPT; 1949 alarm(shutdowntimeout); 1950 clang = 0; 1951 /* 1952 * Copied from single_user(). This is a bit paranoid. 1953 * Use the same ALRM handler. 1954 */ 1955 do { 1956 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1957 collect_child(wpid); 1958 if (clang == 1) { 1959 /* we were waiting for the sub-shell */ 1960 kill(wpid, SIGTERM); 1961 warning("timeout expired for %s: %m; going to " 1962 "single user mode", _PATH_RUNDOWN); 1963 return -1; 1964 } 1965 if (wpid == -1) { 1966 if (errno == EINTR) 1967 continue; 1968 warning("wait for %s failed: %m; going to " 1969 "single user mode", _PATH_RUNDOWN); 1970 return -1; 1971 } 1972 if (wpid == pid && WIFSTOPPED(status)) { 1973 warning("init: %s stopped, restarting\n", 1974 _PATH_RUNDOWN); 1975 kill(pid, SIGCONT); 1976 wpid = -1; 1977 } 1978 } while (wpid != pid && !clang); 1979 1980 /* Turn off the alarm */ 1981 alarm(0); 1982 1983 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1984 requested_transition == catatonia) { 1985 /* 1986 * /etc/rc.shutdown executed /sbin/reboot; 1987 * wait for the end quietly 1988 */ 1989 sigset_t s; 1990 1991 sigfillset(&s); 1992 for (;;) 1993 sigsuspend(&s); 1994 } 1995 1996 if (!WIFEXITED(status)) { 1997 warning("%s terminated abnormally, going to " 1998 "single user mode", _PATH_RUNDOWN); 1999 return -2; 2000 } 2001 2002 if ((status = WEXITSTATUS(status)) != 0) 2003 warning("%s returned status %d", _PATH_RUNDOWN, status); 2004 2005 return status; 2006 } 2007 2008 static char * 2009 strk(char *p) 2010 { 2011 static char *t; 2012 char *q; 2013 int c; 2014 2015 if (p) 2016 t = p; 2017 if (!t) 2018 return 0; 2019 2020 c = *t; 2021 while (c == ' ' || c == '\t' ) 2022 c = *++t; 2023 if (!c) { 2024 t = 0; 2025 return 0; 2026 } 2027 q = t; 2028 if (c == '\'') { 2029 c = *++t; 2030 q = t; 2031 while (c && c != '\'') 2032 c = *++t; 2033 if (!c) /* unterminated string */ 2034 q = t = 0; 2035 else 2036 *t++ = 0; 2037 } else { 2038 while (c && c != ' ' && c != '\t' ) 2039 c = *++t; 2040 *t++ = 0; 2041 if (!c) 2042 t = 0; 2043 } 2044 return q; 2045 } 2046 2047 #ifdef LOGIN_CAP 2048 static void 2049 setprocresources(const char *cname) 2050 { 2051 login_cap_t *lc; 2052 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 2053 setusercontext(lc, (struct passwd*)NULL, 0, 2054 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2055 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2056 login_close(lc); 2057 } 2058 } 2059 #endif 2060