init.c revision 346479
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Donn Seeley at Berkeley Software Design, Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34static const char copyright[] = 35"@(#) Copyright (c) 1991, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37#endif /* not lint */ 38 39#ifndef lint 40#if 0 41static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93"; 42#endif 43static const char rcsid[] = 44 "$FreeBSD: stable/11/sbin/init/init.c 346479 2019-04-21 04:00:19Z kevans $"; 45#endif /* not lint */ 46 47#include <sys/param.h> 48#include <sys/ioctl.h> 49#include <sys/mman.h> 50#include <sys/mount.h> 51#include <sys/sysctl.h> 52#include <sys/wait.h> 53#include <sys/stat.h> 54#include <sys/uio.h> 55 56#include <db.h> 57#include <errno.h> 58#include <fcntl.h> 59#include <kenv.h> 60#include <libutil.h> 61#include <paths.h> 62#include <signal.h> 63#include <stdio.h> 64#include <stdlib.h> 65#include <string.h> 66#include <syslog.h> 67#include <time.h> 68#include <ttyent.h> 69#include <unistd.h> 70#include <sys/reboot.h> 71#include <err.h> 72 73#include <stdarg.h> 74 75#ifdef SECURE 76#include <pwd.h> 77#endif 78 79#ifdef LOGIN_CAP 80#include <login_cap.h> 81#endif 82 83#include "mntopts.h" 84#include "pathnames.h" 85 86/* 87 * Sleep times; used to prevent thrashing. 88 */ 89#define GETTY_SPACING 5 /* N secs minimum getty spacing */ 90#define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 91#define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ 92#define WINDOW_WAIT 3 /* wait N secs after starting window */ 93#define STALL_TIMEOUT 30 /* wait N secs after warning */ 94#define DEATH_WATCH 10 /* wait N secs for procs to die */ 95#define DEATH_SCRIPT 120 /* wait for 2min for /etc/rc.shutdown */ 96#define RESOURCE_RC "daemon" 97#define RESOURCE_WINDOW "default" 98#define RESOURCE_GETTY "default" 99 100static void handle(sig_t, ...); 101static void delset(sigset_t *, ...); 102 103static void stall(const char *, ...) __printflike(1, 2); 104static void warning(const char *, ...) __printflike(1, 2); 105static void emergency(const char *, ...) __printflike(1, 2); 106static void disaster(int); 107static void badsys(int); 108static void revoke_ttys(void); 109static int runshutdown(void); 110static char *strk(char *); 111 112/* 113 * We really need a recursive typedef... 114 * The following at least guarantees that the return type of (*state_t)() 115 * is sufficiently wide to hold a function pointer. 116 */ 117typedef long (*state_func_t)(void); 118typedef state_func_t (*state_t)(void); 119 120static state_func_t single_user(void); 121static state_func_t runcom(void); 122static state_func_t read_ttys(void); 123static state_func_t multi_user(void); 124static state_func_t clean_ttys(void); 125static state_func_t catatonia(void); 126static state_func_t death(void); 127static state_func_t death_single(void); 128static state_func_t reroot(void); 129static state_func_t reroot_phase_two(void); 130 131static state_func_t run_script(const char *); 132 133static enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 134#define FALSE 0 135#define TRUE 1 136 137static int Reboot = FALSE; 138static int howto = RB_AUTOBOOT; 139 140static int devfs; 141static char *init_path_argv0; 142 143static void transition(state_t); 144static state_t requested_transition; 145static state_t current_state = death_single; 146 147static void open_console(void); 148static const char *get_shell(void); 149static void replace_init(char *path); 150static void write_stderr(const char *message); 151 152typedef struct init_session { 153 pid_t se_process; /* controlling process */ 154 time_t se_started; /* used to avoid thrashing */ 155 int se_flags; /* status of session */ 156#define SE_SHUTDOWN 0x1 /* session won't be restarted */ 157#define SE_PRESENT 0x2 /* session is in /etc/ttys */ 158#define SE_IFEXISTS 0x4 /* session defined as "onifexists" */ 159#define SE_IFCONSOLE 0x8 /* session defined as "onifconsole" */ 160 int se_nspace; /* spacing count */ 161 char *se_device; /* filename of port */ 162 char *se_getty; /* what to run on that port */ 163 char *se_getty_argv_space; /* pre-parsed argument array space */ 164 char **se_getty_argv; /* pre-parsed argument array */ 165 char *se_window; /* window system (started only once) */ 166 char *se_window_argv_space; /* pre-parsed argument array space */ 167 char **se_window_argv; /* pre-parsed argument array */ 168 char *se_type; /* default terminal type */ 169 struct init_session *se_prev; 170 struct init_session *se_next; 171} session_t; 172 173static void free_session(session_t *); 174static session_t *new_session(session_t *, struct ttyent *); 175static session_t *sessions; 176 177static char **construct_argv(char *); 178static void start_window_system(session_t *); 179static void collect_child(pid_t); 180static pid_t start_getty(session_t *); 181static void transition_handler(int); 182static void alrm_handler(int); 183static void setsecuritylevel(int); 184static int getsecuritylevel(void); 185static int setupargv(session_t *, struct ttyent *); 186#ifdef LOGIN_CAP 187static void setprocresources(const char *); 188#endif 189static int clang; 190 191static int start_session_db(void); 192static void add_session(session_t *); 193static void del_session(session_t *); 194static session_t *find_session(pid_t); 195static DB *session_db; 196 197/* 198 * The mother of all processes. 199 */ 200int 201main(int argc, char *argv[]) 202{ 203 state_t initial_transition = runcom; 204 char kenv_value[PATH_MAX]; 205 int c, error; 206 struct sigaction sa; 207 sigset_t mask; 208 209 /* Dispose of random users. */ 210 if (getuid() != 0) 211 errx(1, "%s", strerror(EPERM)); 212 213 /* System V users like to reexec init. */ 214 if (getpid() != 1) { 215#ifdef COMPAT_SYSV_INIT 216 /* So give them what they want */ 217 if (argc > 1) { 218 if (strlen(argv[1]) == 1) { 219 char runlevel = *argv[1]; 220 int sig; 221 222 switch (runlevel) { 223 case '0': /* halt + poweroff */ 224 sig = SIGUSR2; 225 break; 226 case '1': /* single-user */ 227 sig = SIGTERM; 228 break; 229 case '6': /* reboot */ 230 sig = SIGINT; 231 break; 232 case 'c': /* block further logins */ 233 sig = SIGTSTP; 234 break; 235 case 'q': /* rescan /etc/ttys */ 236 sig = SIGHUP; 237 break; 238 case 'r': /* remount root */ 239 sig = SIGEMT; 240 break; 241 default: 242 goto invalid; 243 } 244 kill(1, sig); 245 _exit(0); 246 } else 247invalid: 248 errx(1, "invalid run-level ``%s''", argv[1]); 249 } else 250#endif 251 errx(1, "already running"); 252 } 253 254 init_path_argv0 = strdup(argv[0]); 255 if (init_path_argv0 == NULL) 256 err(1, "strdup"); 257 258 /* 259 * Note that this does NOT open a file... 260 * Does 'init' deserve its own facility number? 261 */ 262 openlog("init", LOG_CONS, LOG_AUTH); 263 264 /* 265 * Create an initial session. 266 */ 267 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 268 warning("initial setsid() failed: %m"); 269 270 /* 271 * Establish an initial user so that programs running 272 * single user do not freak out and die (like passwd). 273 */ 274 if (setlogin("root") < 0) 275 warning("setlogin() failed: %m"); 276 277 /* 278 * This code assumes that we always get arguments through flags, 279 * never through bits set in some random machine register. 280 */ 281 while ((c = getopt(argc, argv, "dsfr")) != -1) 282 switch (c) { 283 case 'd': 284 devfs = 1; 285 break; 286 case 's': 287 initial_transition = single_user; 288 break; 289 case 'f': 290 runcom_mode = FASTBOOT; 291 break; 292 case 'r': 293 initial_transition = reroot_phase_two; 294 break; 295 default: 296 warning("unrecognized flag '-%c'", c); 297 break; 298 } 299 300 if (optind != argc) 301 warning("ignoring excess arguments"); 302 303 /* 304 * We catch or block signals rather than ignore them, 305 * so that they get reset on exec. 306 */ 307 handle(badsys, SIGSYS, 0); 308 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 309 SIGXFSZ, 0); 310 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 311 SIGUSR1, SIGUSR2, 0); 312 handle(alrm_handler, SIGALRM, 0); 313 sigfillset(&mask); 314 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 315 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 316 SIGALRM, SIGUSR1, SIGUSR2, 0); 317 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 318 sigemptyset(&sa.sa_mask); 319 sa.sa_flags = 0; 320 sa.sa_handler = SIG_IGN; 321 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 322 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 323 324 /* 325 * Paranoia. 326 */ 327 close(0); 328 close(1); 329 close(2); 330 331 if (kenv(KENV_GET, "init_exec", kenv_value, sizeof(kenv_value)) > 0) { 332 replace_init(kenv_value); 333 _exit(0); /* reboot */ 334 } 335 336 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 337 state_func_t next_transition; 338 339 if ((next_transition = run_script(kenv_value)) != NULL) 340 initial_transition = (state_t) next_transition; 341 } 342 343 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 344 if (chdir(kenv_value) != 0 || chroot(".") != 0) 345 warning("Can't chroot to %s: %m", kenv_value); 346 } 347 348 /* 349 * Additional check if devfs needs to be mounted: 350 * If "/" and "/dev" have the same device number, 351 * then it hasn't been mounted yet. 352 */ 353 if (!devfs) { 354 struct stat stst; 355 dev_t root_devno; 356 357 stat("/", &stst); 358 root_devno = stst.st_dev; 359 if (stat("/dev", &stst) != 0) 360 warning("Can't stat /dev: %m"); 361 else if (stst.st_dev == root_devno) 362 devfs++; 363 } 364 365 if (devfs) { 366 struct iovec iov[4]; 367 char *s; 368 int i; 369 370 char _fstype[] = "fstype"; 371 char _devfs[] = "devfs"; 372 char _fspath[] = "fspath"; 373 char _path_dev[]= _PATH_DEV; 374 375 iov[0].iov_base = _fstype; 376 iov[0].iov_len = sizeof(_fstype); 377 iov[1].iov_base = _devfs; 378 iov[1].iov_len = sizeof(_devfs); 379 iov[2].iov_base = _fspath; 380 iov[2].iov_len = sizeof(_fspath); 381 /* 382 * Try to avoid the trailing slash in _PATH_DEV. 383 * Be *very* defensive. 384 */ 385 s = strdup(_PATH_DEV); 386 if (s != NULL) { 387 i = strlen(s); 388 if (i > 0 && s[i - 1] == '/') 389 s[i - 1] = '\0'; 390 iov[3].iov_base = s; 391 iov[3].iov_len = strlen(s) + 1; 392 } else { 393 iov[3].iov_base = _path_dev; 394 iov[3].iov_len = sizeof(_path_dev); 395 } 396 nmount(iov, 4, 0); 397 if (s != NULL) 398 free(s); 399 } 400 401 if (initial_transition != reroot_phase_two) { 402 /* 403 * Unmount reroot leftovers. This runs after init(8) 404 * gets reexecuted after reroot_phase_two() is done. 405 */ 406 error = unmount(_PATH_REROOT, MNT_FORCE); 407 if (error != 0 && errno != EINVAL) 408 warning("Cannot unmount %s: %m", _PATH_REROOT); 409 } 410 411 /* 412 * Start the state machine. 413 */ 414 transition(initial_transition); 415 416 /* 417 * Should never reach here. 418 */ 419 return 1; 420} 421 422/* 423 * Associate a function with a signal handler. 424 */ 425static void 426handle(sig_t handler, ...) 427{ 428 int sig; 429 struct sigaction sa; 430 sigset_t mask_everything; 431 va_list ap; 432 va_start(ap, handler); 433 434 sa.sa_handler = handler; 435 sigfillset(&mask_everything); 436 437 while ((sig = va_arg(ap, int)) != 0) { 438 sa.sa_mask = mask_everything; 439 /* XXX SA_RESTART? */ 440 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 441 sigaction(sig, &sa, (struct sigaction *) 0); 442 } 443 va_end(ap); 444} 445 446/* 447 * Delete a set of signals from a mask. 448 */ 449static void 450delset(sigset_t *maskp, ...) 451{ 452 int sig; 453 va_list ap; 454 va_start(ap, maskp); 455 456 while ((sig = va_arg(ap, int)) != 0) 457 sigdelset(maskp, sig); 458 va_end(ap); 459} 460 461/* 462 * Log a message and sleep for a while (to give someone an opportunity 463 * to read it and to save log or hardcopy output if the problem is chronic). 464 * NB: should send a message to the session logger to avoid blocking. 465 */ 466static void 467stall(const char *message, ...) 468{ 469 va_list ap; 470 va_start(ap, message); 471 472 vsyslog(LOG_ALERT, message, ap); 473 va_end(ap); 474 sleep(STALL_TIMEOUT); 475} 476 477/* 478 * Like stall(), but doesn't sleep. 479 * If cpp had variadic macros, the two functions could be #defines for another. 480 * NB: should send a message to the session logger to avoid blocking. 481 */ 482static void 483warning(const char *message, ...) 484{ 485 va_list ap; 486 va_start(ap, message); 487 488 vsyslog(LOG_ALERT, message, ap); 489 va_end(ap); 490} 491 492/* 493 * Log an emergency message. 494 * NB: should send a message to the session logger to avoid blocking. 495 */ 496static void 497emergency(const char *message, ...) 498{ 499 va_list ap; 500 va_start(ap, message); 501 502 vsyslog(LOG_EMERG, message, ap); 503 va_end(ap); 504} 505 506/* 507 * Catch a SIGSYS signal. 508 * 509 * These may arise if a system does not support sysctl. 510 * We tolerate up to 25 of these, then throw in the towel. 511 */ 512static void 513badsys(int sig) 514{ 515 static int badcount = 0; 516 517 if (badcount++ < 25) 518 return; 519 disaster(sig); 520} 521 522/* 523 * Catch an unexpected signal. 524 */ 525static void 526disaster(int sig) 527{ 528 529 emergency("fatal signal: %s", 530 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 531 532 sleep(STALL_TIMEOUT); 533 _exit(sig); /* reboot */ 534} 535 536/* 537 * Get the security level of the kernel. 538 */ 539static int 540getsecuritylevel(void) 541{ 542#ifdef KERN_SECURELVL 543 int name[2], curlevel; 544 size_t len; 545 546 name[0] = CTL_KERN; 547 name[1] = KERN_SECURELVL; 548 len = sizeof curlevel; 549 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 550 emergency("cannot get kernel security level: %s", 551 strerror(errno)); 552 return (-1); 553 } 554 return (curlevel); 555#else 556 return (-1); 557#endif 558} 559 560/* 561 * Set the security level of the kernel. 562 */ 563static void 564setsecuritylevel(int newlevel) 565{ 566#ifdef KERN_SECURELVL 567 int name[2], curlevel; 568 569 curlevel = getsecuritylevel(); 570 if (newlevel == curlevel) 571 return; 572 name[0] = CTL_KERN; 573 name[1] = KERN_SECURELVL; 574 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 575 emergency( 576 "cannot change kernel security level from %d to %d: %s", 577 curlevel, newlevel, strerror(errno)); 578 return; 579 } 580#ifdef SECURE 581 warning("kernel security level changed from %d to %d", 582 curlevel, newlevel); 583#endif 584#endif 585} 586 587/* 588 * Change states in the finite state machine. 589 * The initial state is passed as an argument. 590 */ 591static void 592transition(state_t s) 593{ 594 595 current_state = s; 596 for (;;) 597 current_state = (state_t) (*current_state)(); 598} 599 600/* 601 * Start a session and allocate a controlling terminal. 602 * Only called by children of init after forking. 603 */ 604static void 605open_console(void) 606{ 607 int fd; 608 609 /* 610 * Try to open /dev/console. Open the device with O_NONBLOCK to 611 * prevent potential blocking on a carrier. 612 */ 613 revoke(_PATH_CONSOLE); 614 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 615 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 616 if (login_tty(fd) == 0) 617 return; 618 close(fd); 619 } 620 621 /* No luck. Log output to file if possible. */ 622 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 623 stall("cannot open null device."); 624 _exit(1); 625 } 626 if (fd != STDIN_FILENO) { 627 dup2(fd, STDIN_FILENO); 628 close(fd); 629 } 630 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 631 if (fd == -1) 632 dup2(STDIN_FILENO, STDOUT_FILENO); 633 else if (fd != STDOUT_FILENO) { 634 dup2(fd, STDOUT_FILENO); 635 close(fd); 636 } 637 dup2(STDOUT_FILENO, STDERR_FILENO); 638} 639 640static const char * 641get_shell(void) 642{ 643 static char kenv_value[PATH_MAX]; 644 645 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 646 return kenv_value; 647 else 648 return _PATH_BSHELL; 649} 650 651static void 652write_stderr(const char *message) 653{ 654 655 write(STDERR_FILENO, message, strlen(message)); 656} 657 658static int 659read_file(const char *path, void **bufp, size_t *bufsizep) 660{ 661 struct stat sb; 662 size_t bufsize; 663 void *buf; 664 ssize_t nbytes; 665 int error, fd; 666 667 fd = open(path, O_RDONLY); 668 if (fd < 0) { 669 emergency("%s: %s", path, strerror(errno)); 670 return (-1); 671 } 672 673 error = fstat(fd, &sb); 674 if (error != 0) { 675 emergency("fstat: %s", strerror(errno)); 676 close(fd); 677 return (error); 678 } 679 680 bufsize = sb.st_size; 681 buf = malloc(bufsize); 682 if (buf == NULL) { 683 emergency("malloc: %s", strerror(errno)); 684 close(fd); 685 return (error); 686 } 687 688 nbytes = read(fd, buf, bufsize); 689 if (nbytes != (ssize_t)bufsize) { 690 emergency("read: %s", strerror(errno)); 691 close(fd); 692 free(buf); 693 return (error); 694 } 695 696 error = close(fd); 697 if (error != 0) { 698 emergency("close: %s", strerror(errno)); 699 free(buf); 700 return (error); 701 } 702 703 *bufp = buf; 704 *bufsizep = bufsize; 705 706 return (0); 707} 708 709static int 710create_file(const char *path, const void *buf, size_t bufsize) 711{ 712 ssize_t nbytes; 713 int error, fd; 714 715 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 716 if (fd < 0) { 717 emergency("%s: %s", path, strerror(errno)); 718 return (-1); 719 } 720 721 nbytes = write(fd, buf, bufsize); 722 if (nbytes != (ssize_t)bufsize) { 723 emergency("write: %s", strerror(errno)); 724 close(fd); 725 return (-1); 726 } 727 728 error = close(fd); 729 if (error != 0) { 730 emergency("close: %s", strerror(errno)); 731 return (-1); 732 } 733 734 return (0); 735} 736 737static int 738mount_tmpfs(const char *fspath) 739{ 740 struct iovec *iov; 741 char errmsg[255]; 742 int error, iovlen; 743 744 iov = NULL; 745 iovlen = 0; 746 memset(errmsg, 0, sizeof(errmsg)); 747 build_iovec(&iov, &iovlen, "fstype", 748 __DECONST(void *, "tmpfs"), (size_t)-1); 749 build_iovec(&iov, &iovlen, "fspath", 750 __DECONST(void *, fspath), (size_t)-1); 751 build_iovec(&iov, &iovlen, "errmsg", 752 errmsg, sizeof(errmsg)); 753 754 error = nmount(iov, iovlen, 0); 755 if (error != 0) { 756 if (*errmsg != '\0') { 757 emergency("cannot mount tmpfs on %s: %s: %s", 758 fspath, errmsg, strerror(errno)); 759 } else { 760 emergency("cannot mount tmpfs on %s: %s", 761 fspath, strerror(errno)); 762 } 763 return (error); 764 } 765 return (0); 766} 767 768static state_func_t 769reroot(void) 770{ 771 void *buf; 772 size_t bufsize; 773 int error; 774 775 buf = NULL; 776 bufsize = 0; 777 778 revoke_ttys(); 779 runshutdown(); 780 781 /* 782 * Make sure nobody can interfere with our scheme. 783 * Ignore ESRCH, which can apparently happen when 784 * there are no processes to kill. 785 */ 786 error = kill(-1, SIGKILL); 787 if (error != 0 && errno != ESRCH) { 788 emergency("kill(2) failed: %s", strerror(errno)); 789 goto out; 790 } 791 792 /* 793 * Copy the init binary into tmpfs, so that we can unmount 794 * the old rootfs without committing suicide. 795 */ 796 error = read_file(init_path_argv0, &buf, &bufsize); 797 if (error != 0) 798 goto out; 799 error = mount_tmpfs(_PATH_REROOT); 800 if (error != 0) 801 goto out; 802 error = create_file(_PATH_REROOT_INIT, buf, bufsize); 803 if (error != 0) 804 goto out; 805 806 /* 807 * Execute the temporary init. 808 */ 809 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); 810 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno)); 811 812out: 813 emergency("reroot failed; going to single user mode"); 814 free(buf); 815 return (state_func_t) single_user; 816} 817 818static state_func_t 819reroot_phase_two(void) 820{ 821 char init_path[PATH_MAX], *path, *path_component; 822 size_t init_path_len; 823 int nbytes, error; 824 825 /* 826 * Ask the kernel to mount the new rootfs. 827 */ 828 error = reboot(RB_REROOT); 829 if (error != 0) { 830 emergency("RB_REBOOT failed: %s", strerror(errno)); 831 goto out; 832 } 833 834 /* 835 * Figure out where the destination init(8) binary is. Note that 836 * the path could be different than what we've started with. Use 837 * the value from kenv, if set, or the one from sysctl otherwise. 838 * The latter defaults to a hardcoded value, but can be overridden 839 * by a build time option. 840 */ 841 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 842 if (nbytes <= 0) { 843 init_path_len = sizeof(init_path); 844 error = sysctlbyname("kern.init_path", 845 init_path, &init_path_len, NULL, 0); 846 if (error != 0) { 847 emergency("failed to retrieve kern.init_path: %s", 848 strerror(errno)); 849 goto out; 850 } 851 } 852 853 /* 854 * Repeat the init search logic from sys/kern/init_path.c 855 */ 856 path_component = init_path; 857 while ((path = strsep(&path_component, ":")) != NULL) { 858 /* 859 * Execute init(8) from the new rootfs. 860 */ 861 execl(path, path, NULL); 862 } 863 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 864 865out: 866 emergency("reroot failed; going to single user mode"); 867 return (state_func_t) single_user; 868} 869 870/* 871 * Bring the system up single user. 872 */ 873static state_func_t 874single_user(void) 875{ 876 pid_t pid, wpid; 877 int status; 878 sigset_t mask; 879 const char *shell; 880 char *argv[2]; 881 struct timeval tv, tn; 882#ifdef SECURE 883 struct ttyent *typ; 884 struct passwd *pp; 885 static const char banner[] = 886 "Enter root password, or ^D to go multi-user\n"; 887 char *clear, *password; 888#endif 889#ifdef DEBUGSHELL 890 char altshell[128]; 891#endif 892 893 if (Reboot) { 894 /* Instead of going single user, let's reboot the machine */ 895 sync(); 896 if (reboot(howto) == -1) { 897 emergency("reboot(%#x) failed, %s", howto, 898 strerror(errno)); 899 _exit(1); /* panic and reboot */ 900 } 901 warning("reboot(%#x) returned", howto); 902 _exit(0); /* panic as well */ 903 } 904 905 shell = get_shell(); 906 907 if ((pid = fork()) == 0) { 908 /* 909 * Start the single user session. 910 */ 911 open_console(); 912 913#ifdef SECURE 914 /* 915 * Check the root password. 916 * We don't care if the console is 'on' by default; 917 * it's the only tty that can be 'off' and 'secure'. 918 */ 919 typ = getttynam("console"); 920 pp = getpwnam("root"); 921 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 922 pp && *pp->pw_passwd) { 923 write_stderr(banner); 924 for (;;) { 925 clear = getpass("Password:"); 926 if (clear == NULL || *clear == '\0') 927 _exit(0); 928 password = crypt(clear, pp->pw_passwd); 929 bzero(clear, _PASSWORD_LEN); 930 if (password == NULL || 931 strcmp(password, pp->pw_passwd) == 0) 932 break; 933 warning("single-user login failed\n"); 934 } 935 } 936 endttyent(); 937 endpwent(); 938#endif /* SECURE */ 939 940#ifdef DEBUGSHELL 941 { 942 char *cp = altshell; 943 int num; 944 945#define SHREQUEST "Enter full pathname of shell or RETURN for " 946 write_stderr(SHREQUEST); 947 write_stderr(shell); 948 write_stderr(": "); 949 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 950 num != 0 && *cp != '\n' && cp < &altshell[127]) 951 cp++; 952 *cp = '\0'; 953 if (altshell[0] != '\0') 954 shell = altshell; 955 } 956#endif /* DEBUGSHELL */ 957 958 /* 959 * Unblock signals. 960 * We catch all the interesting ones, 961 * and those are reset to SIG_DFL on exec. 962 */ 963 sigemptyset(&mask); 964 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 965 966 /* 967 * Fire off a shell. 968 * If the default one doesn't work, try the Bourne shell. 969 */ 970 971 char name[] = "-sh"; 972 973 argv[0] = name; 974 argv[1] = NULL; 975 execv(shell, argv); 976 emergency("can't exec %s for single user: %m", shell); 977 execv(_PATH_BSHELL, argv); 978 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 979 sleep(STALL_TIMEOUT); 980 _exit(1); 981 } 982 983 if (pid == -1) { 984 /* 985 * We are seriously hosed. Do our best. 986 */ 987 emergency("can't fork single-user shell, trying again"); 988 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 989 continue; 990 return (state_func_t) single_user; 991 } 992 993 requested_transition = 0; 994 do { 995 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 996 collect_child(wpid); 997 if (wpid == -1) { 998 if (errno == EINTR) 999 continue; 1000 warning("wait for single-user shell failed: %m; restarting"); 1001 return (state_func_t) single_user; 1002 } 1003 if (wpid == pid && WIFSTOPPED(status)) { 1004 warning("init: shell stopped, restarting\n"); 1005 kill(pid, SIGCONT); 1006 wpid = -1; 1007 } 1008 } while (wpid != pid && !requested_transition); 1009 1010 if (requested_transition) 1011 return (state_func_t) requested_transition; 1012 1013 if (!WIFEXITED(status)) { 1014 if (WTERMSIG(status) == SIGKILL) { 1015 /* 1016 * reboot(8) killed shell? 1017 */ 1018 warning("single user shell terminated."); 1019 gettimeofday(&tv, NULL); 1020 tn = tv; 1021 tv.tv_sec += STALL_TIMEOUT; 1022 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == 1023 tn.tv_sec && tv.tv_usec > tn.tv_usec)) { 1024 sleep(1); 1025 gettimeofday(&tn, NULL); 1026 } 1027 _exit(0); 1028 } else { 1029 warning("single user shell terminated, restarting"); 1030 return (state_func_t) single_user; 1031 } 1032 } 1033 1034 runcom_mode = FASTBOOT; 1035 return (state_func_t) runcom; 1036} 1037 1038/* 1039 * Run the system startup script. 1040 */ 1041static state_func_t 1042runcom(void) 1043{ 1044 state_func_t next_transition; 1045 1046 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL) 1047 return next_transition; 1048 1049 runcom_mode = AUTOBOOT; /* the default */ 1050 return (state_func_t) read_ttys; 1051} 1052 1053/* 1054 * Execute binary, replacing init(8) as PID 1. 1055 */ 1056static void 1057replace_init(char *path) 1058{ 1059 char *argv[3]; 1060 char sh[] = "sh"; 1061 1062 argv[0] = sh; 1063 argv[1] = path; 1064 argv[2] = NULL; 1065 1066 execute_script(argv); 1067} 1068 1069/* 1070 * Run a shell script. 1071 * Returns 0 on success, otherwise the next transition to enter: 1072 * - single_user if fork/execv/waitpid failed, or if the script 1073 * terminated with a signal or exit code != 0. 1074 * - death_single if a SIGTERM was delivered to init(8). 1075 */ 1076static state_func_t 1077run_script(const char *script) 1078{ 1079 pid_t pid, wpid; 1080 int error, status; 1081 char *argv[4]; 1082 const char *shell; 1083 struct sigaction sa; 1084 1085 shell = get_shell(); 1086 1087 if ((pid = fork()) == 0) { 1088 sigemptyset(&sa.sa_mask); 1089 sa.sa_flags = 0; 1090 sa.sa_handler = SIG_IGN; 1091 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1092 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1093 1094 open_console(); 1095 1096 char _sh[] = "sh"; 1097 char _autoboot[] = "autoboot"; 1098 1099 argv[0] = _sh; 1100 argv[1] = __DECONST(char *, script); 1101 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1102 argv[3] = NULL; 1103 1104 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1105 1106#ifdef LOGIN_CAP 1107 setprocresources(RESOURCE_RC); 1108#endif 1109 1110 /* 1111 * Try to directly execute the script first. If it 1112 * fails, try the old method of passing the script path 1113 * to sh(1). Don't complain if it fails because of 1114 * the missing execute bit. 1115 */ 1116 error = access(script, X_OK); 1117 if (error == 0) { 1118 execv(script, argv + 1); 1119 warning("can't exec %s: %m", script); 1120 } else if (errno != EACCES) { 1121 warning("can't access %s: %m", script); 1122 } 1123 1124 execv(shell, argv); 1125 stall("can't exec %s for %s: %m", shell, script); 1126 _exit(1); /* force single user mode */ 1127 } 1128 1129 if (pid == -1) { 1130 emergency("can't fork for %s on %s: %m", shell, script); 1131 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1132 continue; 1133 sleep(STALL_TIMEOUT); 1134 return (state_func_t) single_user; 1135 } 1136 1137 /* 1138 * Copied from single_user(). This is a bit paranoid. 1139 */ 1140 requested_transition = 0; 1141 do { 1142 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1143 collect_child(wpid); 1144 if (wpid == -1) { 1145 if (requested_transition == death_single || 1146 requested_transition == reroot) 1147 return (state_func_t) requested_transition; 1148 if (errno == EINTR) 1149 continue; 1150 warning("wait for %s on %s failed: %m; going to " 1151 "single user mode", shell, script); 1152 return (state_func_t) single_user; 1153 } 1154 if (wpid == pid && WIFSTOPPED(status)) { 1155 warning("init: %s on %s stopped, restarting\n", 1156 shell, script); 1157 kill(pid, SIGCONT); 1158 wpid = -1; 1159 } 1160 } while (wpid != pid); 1161 1162 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1163 requested_transition == catatonia) { 1164 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1165 sigset_t s; 1166 1167 sigfillset(&s); 1168 for (;;) 1169 sigsuspend(&s); 1170 } 1171 1172 if (!WIFEXITED(status)) { 1173 warning("%s on %s terminated abnormally, going to single " 1174 "user mode", shell, script); 1175 return (state_func_t) single_user; 1176 } 1177 1178 if (WEXITSTATUS(status)) 1179 return (state_func_t) single_user; 1180 1181 return (state_func_t) 0; 1182} 1183 1184/* 1185 * Open the session database. 1186 * 1187 * NB: We could pass in the size here; is it necessary? 1188 */ 1189static int 1190start_session_db(void) 1191{ 1192 if (session_db && (*session_db->close)(session_db)) 1193 emergency("session database close: %s", strerror(errno)); 1194 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 1195 emergency("session database open: %s", strerror(errno)); 1196 return (1); 1197 } 1198 return (0); 1199 1200} 1201 1202/* 1203 * Add a new login session. 1204 */ 1205static void 1206add_session(session_t *sp) 1207{ 1208 DBT key; 1209 DBT data; 1210 1211 key.data = &sp->se_process; 1212 key.size = sizeof sp->se_process; 1213 data.data = &sp; 1214 data.size = sizeof sp; 1215 1216 if ((*session_db->put)(session_db, &key, &data, 0)) 1217 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1218} 1219 1220/* 1221 * Delete an old login session. 1222 */ 1223static void 1224del_session(session_t *sp) 1225{ 1226 DBT key; 1227 1228 key.data = &sp->se_process; 1229 key.size = sizeof sp->se_process; 1230 1231 if ((*session_db->del)(session_db, &key, 0)) 1232 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1233} 1234 1235/* 1236 * Look up a login session by pid. 1237 */ 1238static session_t * 1239find_session(pid_t pid) 1240{ 1241 DBT key; 1242 DBT data; 1243 session_t *ret; 1244 1245 key.data = &pid; 1246 key.size = sizeof pid; 1247 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1248 return 0; 1249 bcopy(data.data, (char *)&ret, sizeof(ret)); 1250 return ret; 1251} 1252 1253/* 1254 * Construct an argument vector from a command line. 1255 */ 1256static char ** 1257construct_argv(char *command) 1258{ 1259 int argc = 0; 1260 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1261 * sizeof (char *)); 1262 1263 if ((argv[argc++] = strk(command)) == NULL) { 1264 free(argv); 1265 return (NULL); 1266 } 1267 while ((argv[argc++] = strk((char *) 0)) != NULL) 1268 continue; 1269 return argv; 1270} 1271 1272/* 1273 * Deallocate a session descriptor. 1274 */ 1275static void 1276free_session(session_t *sp) 1277{ 1278 free(sp->se_device); 1279 if (sp->se_getty) { 1280 free(sp->se_getty); 1281 free(sp->se_getty_argv_space); 1282 free(sp->se_getty_argv); 1283 } 1284 if (sp->se_window) { 1285 free(sp->se_window); 1286 free(sp->se_window_argv_space); 1287 free(sp->se_window_argv); 1288 } 1289 if (sp->se_type) 1290 free(sp->se_type); 1291 free(sp); 1292} 1293 1294/* 1295 * Allocate a new session descriptor. 1296 * Mark it SE_PRESENT. 1297 */ 1298static session_t * 1299new_session(session_t *sprev, struct ttyent *typ) 1300{ 1301 session_t *sp; 1302 1303 if ((typ->ty_status & TTY_ON) == 0 || 1304 typ->ty_name == 0 || 1305 typ->ty_getty == 0) 1306 return 0; 1307 1308 sp = (session_t *) calloc(1, sizeof (session_t)); 1309 1310 sp->se_flags |= SE_PRESENT; 1311 1312 if ((typ->ty_status & TTY_IFEXISTS) != 0) 1313 sp->se_flags |= SE_IFEXISTS; 1314 1315 if ((typ->ty_status & TTY_IFCONSOLE) != 0) 1316 sp->se_flags |= SE_IFCONSOLE; 1317 1318 if (asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name) < 0) 1319 err(1, "asprintf"); 1320 1321 if (setupargv(sp, typ) == 0) { 1322 free_session(sp); 1323 return (0); 1324 } 1325 1326 sp->se_next = 0; 1327 if (sprev == NULL) { 1328 sessions = sp; 1329 sp->se_prev = 0; 1330 } else { 1331 sprev->se_next = sp; 1332 sp->se_prev = sprev; 1333 } 1334 1335 return sp; 1336} 1337 1338/* 1339 * Calculate getty and if useful window argv vectors. 1340 */ 1341static int 1342setupargv(session_t *sp, struct ttyent *typ) 1343{ 1344 1345 if (sp->se_getty) { 1346 free(sp->se_getty); 1347 free(sp->se_getty_argv_space); 1348 free(sp->se_getty_argv); 1349 } 1350 if (asprintf(&sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name) < 0) 1351 err(1, "asprintf"); 1352 sp->se_getty_argv_space = strdup(sp->se_getty); 1353 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1354 if (sp->se_getty_argv == NULL) { 1355 warning("can't parse getty for port %s", sp->se_device); 1356 free(sp->se_getty); 1357 free(sp->se_getty_argv_space); 1358 sp->se_getty = sp->se_getty_argv_space = 0; 1359 return (0); 1360 } 1361 if (sp->se_window) { 1362 free(sp->se_window); 1363 free(sp->se_window_argv_space); 1364 free(sp->se_window_argv); 1365 } 1366 sp->se_window = sp->se_window_argv_space = 0; 1367 sp->se_window_argv = 0; 1368 if (typ->ty_window) { 1369 sp->se_window = strdup(typ->ty_window); 1370 sp->se_window_argv_space = strdup(sp->se_window); 1371 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1372 if (sp->se_window_argv == NULL) { 1373 warning("can't parse window for port %s", 1374 sp->se_device); 1375 free(sp->se_window_argv_space); 1376 free(sp->se_window); 1377 sp->se_window = sp->se_window_argv_space = 0; 1378 return (0); 1379 } 1380 } 1381 if (sp->se_type) 1382 free(sp->se_type); 1383 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1384 return (1); 1385} 1386 1387/* 1388 * Walk the list of ttys and create sessions for each active line. 1389 */ 1390static state_func_t 1391read_ttys(void) 1392{ 1393 session_t *sp, *snext; 1394 struct ttyent *typ; 1395 1396 /* 1397 * Destroy any previous session state. 1398 * There shouldn't be any, but just in case... 1399 */ 1400 for (sp = sessions; sp; sp = snext) { 1401 snext = sp->se_next; 1402 free_session(sp); 1403 } 1404 sessions = 0; 1405 if (start_session_db()) 1406 return (state_func_t) single_user; 1407 1408 /* 1409 * Allocate a session entry for each active port. 1410 * Note that sp starts at 0. 1411 */ 1412 while ((typ = getttyent()) != NULL) 1413 if ((snext = new_session(sp, typ)) != NULL) 1414 sp = snext; 1415 1416 endttyent(); 1417 1418 return (state_func_t) multi_user; 1419} 1420 1421/* 1422 * Start a window system running. 1423 */ 1424static void 1425start_window_system(session_t *sp) 1426{ 1427 pid_t pid; 1428 sigset_t mask; 1429 char term[64], *env[2]; 1430 int status; 1431 1432 if ((pid = fork()) == -1) { 1433 emergency("can't fork for window system on port %s: %m", 1434 sp->se_device); 1435 /* hope that getty fails and we can try again */ 1436 return; 1437 } 1438 if (pid) { 1439 waitpid(-1, &status, 0); 1440 return; 1441 } 1442 1443 /* reparent window process to the init to not make a zombie on exit */ 1444 if ((pid = fork()) == -1) { 1445 emergency("can't fork for window system on port %s: %m", 1446 sp->se_device); 1447 _exit(1); 1448 } 1449 if (pid) 1450 _exit(0); 1451 1452 sigemptyset(&mask); 1453 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1454 1455 if (setsid() < 0) 1456 emergency("setsid failed (window) %m"); 1457 1458#ifdef LOGIN_CAP 1459 setprocresources(RESOURCE_WINDOW); 1460#endif 1461 if (sp->se_type) { 1462 /* Don't use malloc after fork */ 1463 strcpy(term, "TERM="); 1464 strlcat(term, sp->se_type, sizeof(term)); 1465 env[0] = term; 1466 env[1] = NULL; 1467 } 1468 else 1469 env[0] = NULL; 1470 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1471 stall("can't exec window system '%s' for port %s: %m", 1472 sp->se_window_argv[0], sp->se_device); 1473 _exit(1); 1474} 1475 1476/* 1477 * Start a login session running. 1478 */ 1479static pid_t 1480start_getty(session_t *sp) 1481{ 1482 pid_t pid; 1483 sigset_t mask; 1484 time_t current_time = time((time_t *) 0); 1485 int too_quick = 0; 1486 char term[64], *env[2]; 1487 1488 if (current_time >= sp->se_started && 1489 current_time - sp->se_started < GETTY_SPACING) { 1490 if (++sp->se_nspace > GETTY_NSPACE) { 1491 sp->se_nspace = 0; 1492 too_quick = 1; 1493 } 1494 } else 1495 sp->se_nspace = 0; 1496 1497 /* 1498 * fork(), not vfork() -- we can't afford to block. 1499 */ 1500 if ((pid = fork()) == -1) { 1501 emergency("can't fork for getty on port %s: %m", sp->se_device); 1502 return -1; 1503 } 1504 1505 if (pid) 1506 return pid; 1507 1508 if (too_quick) { 1509 warning("getty repeating too quickly on port %s, sleeping %d secs", 1510 sp->se_device, GETTY_SLEEP); 1511 sleep((unsigned) GETTY_SLEEP); 1512 } 1513 1514 if (sp->se_window) { 1515 start_window_system(sp); 1516 sleep(WINDOW_WAIT); 1517 } 1518 1519 sigemptyset(&mask); 1520 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1521 1522#ifdef LOGIN_CAP 1523 setprocresources(RESOURCE_GETTY); 1524#endif 1525 if (sp->se_type) { 1526 /* Don't use malloc after fork */ 1527 strcpy(term, "TERM="); 1528 strlcat(term, sp->se_type, sizeof(term)); 1529 env[0] = term; 1530 env[1] = NULL; 1531 } else 1532 env[0] = NULL; 1533 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1534 stall("can't exec getty '%s' for port %s: %m", 1535 sp->se_getty_argv[0], sp->se_device); 1536 _exit(1); 1537} 1538 1539/* 1540 * Return 1 if the session is defined as "onifexists" 1541 * or "onifconsole" and the device node does not exist. 1542 */ 1543static int 1544session_has_no_tty(session_t *sp) 1545{ 1546 int fd; 1547 1548 if ((sp->se_flags & SE_IFEXISTS) == 0 && 1549 (sp->se_flags & SE_IFCONSOLE) == 0) 1550 return (0); 1551 1552 fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0); 1553 if (fd < 0) { 1554 if (errno == ENOENT) 1555 return (1); 1556 return (0); 1557 } 1558 1559 close(fd); 1560 return (0); 1561} 1562 1563/* 1564 * Collect exit status for a child. 1565 * If an exiting login, start a new login running. 1566 */ 1567static void 1568collect_child(pid_t pid) 1569{ 1570 session_t *sp, *sprev, *snext; 1571 1572 if (! sessions) 1573 return; 1574 1575 if (! (sp = find_session(pid))) 1576 return; 1577 1578 del_session(sp); 1579 sp->se_process = 0; 1580 1581 if (sp->se_flags & SE_SHUTDOWN || 1582 session_has_no_tty(sp)) { 1583 if ((sprev = sp->se_prev) != NULL) 1584 sprev->se_next = sp->se_next; 1585 else 1586 sessions = sp->se_next; 1587 if ((snext = sp->se_next) != NULL) 1588 snext->se_prev = sp->se_prev; 1589 free_session(sp); 1590 return; 1591 } 1592 1593 if ((pid = start_getty(sp)) == -1) { 1594 /* serious trouble */ 1595 requested_transition = clean_ttys; 1596 return; 1597 } 1598 1599 sp->se_process = pid; 1600 sp->se_started = time((time_t *) 0); 1601 add_session(sp); 1602} 1603 1604/* 1605 * Catch a signal and request a state transition. 1606 */ 1607static void 1608transition_handler(int sig) 1609{ 1610 1611 switch (sig) { 1612 case SIGHUP: 1613 if (current_state == read_ttys || current_state == multi_user || 1614 current_state == clean_ttys || current_state == catatonia) 1615 requested_transition = clean_ttys; 1616 break; 1617 case SIGUSR2: 1618 howto = RB_POWEROFF; 1619 case SIGUSR1: 1620 howto |= RB_HALT; 1621 case SIGINT: 1622 Reboot = TRUE; 1623 case SIGTERM: 1624 if (current_state == read_ttys || current_state == multi_user || 1625 current_state == clean_ttys || current_state == catatonia) 1626 requested_transition = death; 1627 else 1628 requested_transition = death_single; 1629 break; 1630 case SIGTSTP: 1631 if (current_state == runcom || current_state == read_ttys || 1632 current_state == clean_ttys || 1633 current_state == multi_user || current_state == catatonia) 1634 requested_transition = catatonia; 1635 break; 1636 case SIGEMT: 1637 requested_transition = reroot; 1638 break; 1639 default: 1640 requested_transition = 0; 1641 break; 1642 } 1643} 1644 1645/* 1646 * Take the system multiuser. 1647 */ 1648static state_func_t 1649multi_user(void) 1650{ 1651 pid_t pid; 1652 session_t *sp; 1653 1654 requested_transition = 0; 1655 1656 /* 1657 * If the administrator has not set the security level to -1 1658 * to indicate that the kernel should not run multiuser in secure 1659 * mode, and the run script has not set a higher level of security 1660 * than level 1, then put the kernel into secure mode. 1661 */ 1662 if (getsecuritylevel() == 0) 1663 setsecuritylevel(1); 1664 1665 for (sp = sessions; sp; sp = sp->se_next) { 1666 if (sp->se_process) 1667 continue; 1668 if (session_has_no_tty(sp)) 1669 continue; 1670 if ((pid = start_getty(sp)) == -1) { 1671 /* serious trouble */ 1672 requested_transition = clean_ttys; 1673 break; 1674 } 1675 sp->se_process = pid; 1676 sp->se_started = time((time_t *) 0); 1677 add_session(sp); 1678 } 1679 1680 while (!requested_transition) 1681 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1682 collect_child(pid); 1683 1684 return (state_func_t) requested_transition; 1685} 1686 1687/* 1688 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1689 */ 1690static state_func_t 1691clean_ttys(void) 1692{ 1693 session_t *sp, *sprev; 1694 struct ttyent *typ; 1695 int devlen; 1696 char *old_getty, *old_window, *old_type; 1697 1698 /* 1699 * mark all sessions for death, (!SE_PRESENT) 1700 * as we find or create new ones they'll be marked as keepers, 1701 * we'll later nuke all the ones not found in /etc/ttys 1702 */ 1703 for (sp = sessions; sp != NULL; sp = sp->se_next) 1704 sp->se_flags &= ~SE_PRESENT; 1705 1706 devlen = sizeof(_PATH_DEV) - 1; 1707 while ((typ = getttyent()) != NULL) { 1708 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1709 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1710 break; 1711 1712 if (sp) { 1713 /* we want this one to live */ 1714 sp->se_flags |= SE_PRESENT; 1715 if ((typ->ty_status & TTY_ON) == 0 || 1716 typ->ty_getty == 0) { 1717 sp->se_flags |= SE_SHUTDOWN; 1718 kill(sp->se_process, SIGHUP); 1719 continue; 1720 } 1721 sp->se_flags &= ~SE_SHUTDOWN; 1722 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1723 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1724 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1725 if (setupargv(sp, typ) == 0) { 1726 warning("can't parse getty for port %s", 1727 sp->se_device); 1728 sp->se_flags |= SE_SHUTDOWN; 1729 kill(sp->se_process, SIGHUP); 1730 } 1731 else if ( !old_getty 1732 || (!old_type && sp->se_type) 1733 || (old_type && !sp->se_type) 1734 || (!old_window && sp->se_window) 1735 || (old_window && !sp->se_window) 1736 || (strcmp(old_getty, sp->se_getty) != 0) 1737 || (old_window && strcmp(old_window, sp->se_window) != 0) 1738 || (old_type && strcmp(old_type, sp->se_type) != 0) 1739 ) { 1740 /* Don't set SE_SHUTDOWN here */ 1741 sp->se_nspace = 0; 1742 sp->se_started = 0; 1743 kill(sp->se_process, SIGHUP); 1744 } 1745 if (old_getty) 1746 free(old_getty); 1747 if (old_window) 1748 free(old_window); 1749 if (old_type) 1750 free(old_type); 1751 continue; 1752 } 1753 1754 new_session(sprev, typ); 1755 } 1756 1757 endttyent(); 1758 1759 /* 1760 * sweep through and kill all deleted sessions 1761 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1762 */ 1763 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1764 if ((sp->se_flags & SE_PRESENT) == 0) { 1765 sp->se_flags |= SE_SHUTDOWN; 1766 kill(sp->se_process, SIGHUP); 1767 } 1768 } 1769 1770 return (state_func_t) multi_user; 1771} 1772 1773/* 1774 * Block further logins. 1775 */ 1776static state_func_t 1777catatonia(void) 1778{ 1779 session_t *sp; 1780 1781 for (sp = sessions; sp; sp = sp->se_next) 1782 sp->se_flags |= SE_SHUTDOWN; 1783 1784 return (state_func_t) multi_user; 1785} 1786 1787/* 1788 * Note SIGALRM. 1789 */ 1790static void 1791alrm_handler(int sig) 1792{ 1793 1794 (void)sig; 1795 clang = 1; 1796} 1797 1798/* 1799 * Bring the system down to single user. 1800 */ 1801static state_func_t 1802death(void) 1803{ 1804 int block, blocked; 1805 size_t len; 1806 1807 /* Temporarily block suspend. */ 1808 len = sizeof(blocked); 1809 block = 1; 1810 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1811 &block, sizeof(block)) == -1) 1812 blocked = 0; 1813 1814 /* 1815 * Also revoke the TTY here. Because runshutdown() may reopen 1816 * the TTY whose getty we're killing here, there is no guarantee 1817 * runshutdown() will perform the initial open() call, causing 1818 * the terminal attributes to be misconfigured. 1819 */ 1820 revoke_ttys(); 1821 1822 /* Try to run the rc.shutdown script within a period of time */ 1823 runshutdown(); 1824 1825 /* Unblock suspend if we blocked it. */ 1826 if (!blocked) 1827 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1828 &blocked, sizeof(blocked)); 1829 1830 return (state_func_t) death_single; 1831} 1832 1833/* 1834 * Do what is necessary to reinitialize single user mode or reboot 1835 * from an incomplete state. 1836 */ 1837static state_func_t 1838death_single(void) 1839{ 1840 int i; 1841 pid_t pid; 1842 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1843 1844 revoke(_PATH_CONSOLE); 1845 1846 for (i = 0; i < 2; ++i) { 1847 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1848 return (state_func_t) single_user; 1849 1850 clang = 0; 1851 alarm(DEATH_WATCH); 1852 do 1853 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1854 collect_child(pid); 1855 while (clang == 0 && errno != ECHILD); 1856 1857 if (errno == ECHILD) 1858 return (state_func_t) single_user; 1859 } 1860 1861 warning("some processes would not die; ps axl advised"); 1862 1863 return (state_func_t) single_user; 1864} 1865 1866static void 1867revoke_ttys(void) 1868{ 1869 session_t *sp; 1870 1871 for (sp = sessions; sp; sp = sp->se_next) { 1872 sp->se_flags |= SE_SHUTDOWN; 1873 kill(sp->se_process, SIGHUP); 1874 revoke(sp->se_device); 1875 } 1876} 1877 1878/* 1879 * Run the system shutdown script. 1880 * 1881 * Exit codes: XXX I should document more 1882 * -2 shutdown script terminated abnormally 1883 * -1 fatal error - can't run script 1884 * 0 good. 1885 * >0 some error (exit code) 1886 */ 1887static int 1888runshutdown(void) 1889{ 1890 pid_t pid, wpid; 1891 int error, status; 1892 int shutdowntimeout; 1893 size_t len; 1894 char *argv[4]; 1895 const char *shell; 1896 struct sigaction sa; 1897 struct stat sb; 1898 1899 /* 1900 * rc.shutdown is optional, so to prevent any unnecessary 1901 * complaints from the shell we simply don't run it if the 1902 * file does not exist. If the stat() here fails for other 1903 * reasons, we'll let the shell complain. 1904 */ 1905 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1906 return 0; 1907 1908 shell = get_shell(); 1909 1910 if ((pid = fork()) == 0) { 1911 sigemptyset(&sa.sa_mask); 1912 sa.sa_flags = 0; 1913 sa.sa_handler = SIG_IGN; 1914 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1915 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1916 1917 open_console(); 1918 1919 char _sh[] = "sh"; 1920 char _reboot[] = "reboot"; 1921 char _single[] = "single"; 1922 char _path_rundown[] = _PATH_RUNDOWN; 1923 1924 argv[0] = _sh; 1925 argv[1] = _path_rundown; 1926 argv[2] = Reboot ? _reboot : _single; 1927 argv[3] = NULL; 1928 1929 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1930 1931#ifdef LOGIN_CAP 1932 setprocresources(RESOURCE_RC); 1933#endif 1934 1935 /* 1936 * Try to directly execute the script first. If it 1937 * fails, try the old method of passing the script path 1938 * to sh(1). Don't complain if it fails because of 1939 * the missing execute bit. 1940 */ 1941 error = access(_path_rundown, X_OK); 1942 if (error == 0) { 1943 execv(_path_rundown, argv + 1); 1944 warning("can't exec %s: %m", _path_rundown); 1945 } else if (errno != EACCES) { 1946 warning("can't access %s: %m", _path_rundown); 1947 } 1948 1949 execv(shell, argv); 1950 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1951 _exit(1); /* force single user mode */ 1952 } 1953 1954 if (pid == -1) { 1955 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1956 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1957 continue; 1958 sleep(STALL_TIMEOUT); 1959 return -1; 1960 } 1961 1962 len = sizeof(shutdowntimeout); 1963 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1964 NULL, 0) == -1 || shutdowntimeout < 2) 1965 shutdowntimeout = DEATH_SCRIPT; 1966 alarm(shutdowntimeout); 1967 clang = 0; 1968 /* 1969 * Copied from single_user(). This is a bit paranoid. 1970 * Use the same ALRM handler. 1971 */ 1972 do { 1973 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1974 collect_child(wpid); 1975 if (clang == 1) { 1976 /* we were waiting for the sub-shell */ 1977 kill(wpid, SIGTERM); 1978 warning("timeout expired for %s on %s: %m; going to " 1979 "single user mode", shell, _PATH_RUNDOWN); 1980 return -1; 1981 } 1982 if (wpid == -1) { 1983 if (errno == EINTR) 1984 continue; 1985 warning("wait for %s on %s failed: %m; going to " 1986 "single user mode", shell, _PATH_RUNDOWN); 1987 return -1; 1988 } 1989 if (wpid == pid && WIFSTOPPED(status)) { 1990 warning("init: %s on %s stopped, restarting\n", 1991 shell, _PATH_RUNDOWN); 1992 kill(pid, SIGCONT); 1993 wpid = -1; 1994 } 1995 } while (wpid != pid && !clang); 1996 1997 /* Turn off the alarm */ 1998 alarm(0); 1999 2000 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 2001 requested_transition == catatonia) { 2002 /* 2003 * /etc/rc.shutdown executed /sbin/reboot; 2004 * wait for the end quietly 2005 */ 2006 sigset_t s; 2007 2008 sigfillset(&s); 2009 for (;;) 2010 sigsuspend(&s); 2011 } 2012 2013 if (!WIFEXITED(status)) { 2014 warning("%s on %s terminated abnormally, going to " 2015 "single user mode", shell, _PATH_RUNDOWN); 2016 return -2; 2017 } 2018 2019 if ((status = WEXITSTATUS(status)) != 0) 2020 warning("%s returned status %d", _PATH_RUNDOWN, status); 2021 2022 return status; 2023} 2024 2025static char * 2026strk(char *p) 2027{ 2028 static char *t; 2029 char *q; 2030 int c; 2031 2032 if (p) 2033 t = p; 2034 if (!t) 2035 return 0; 2036 2037 c = *t; 2038 while (c == ' ' || c == '\t' ) 2039 c = *++t; 2040 if (!c) { 2041 t = 0; 2042 return 0; 2043 } 2044 q = t; 2045 if (c == '\'') { 2046 c = *++t; 2047 q = t; 2048 while (c && c != '\'') 2049 c = *++t; 2050 if (!c) /* unterminated string */ 2051 q = t = 0; 2052 else 2053 *t++ = 0; 2054 } else { 2055 while (c && c != ' ' && c != '\t' ) 2056 c = *++t; 2057 *t++ = 0; 2058 if (!c) 2059 t = 0; 2060 } 2061 return q; 2062} 2063 2064#ifdef LOGIN_CAP 2065static void 2066setprocresources(const char *cname) 2067{ 2068 login_cap_t *lc; 2069 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 2070 setusercontext(lc, (struct passwd*)NULL, 0, 2071 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2072 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2073 login_close(lc); 2074 } 2075} 2076#endif 2077