init.c revision 308035
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 308035 2016-10-28 12:56:27Z kib $"; 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 write_stderr(const char *message); 150 151typedef struct init_session { 152 pid_t se_process; /* controlling process */ 153 time_t se_started; /* used to avoid thrashing */ 154 int se_flags; /* status of session */ 155#define SE_SHUTDOWN 0x1 /* session won't be restarted */ 156#define SE_PRESENT 0x2 /* session is in /etc/ttys */ 157 int se_nspace; /* spacing count */ 158 char *se_device; /* filename of port */ 159 char *se_getty; /* what to run on that port */ 160 char *se_getty_argv_space; /* pre-parsed argument array space */ 161 char **se_getty_argv; /* pre-parsed argument array */ 162 char *se_window; /* window system (started only once) */ 163 char *se_window_argv_space; /* pre-parsed argument array space */ 164 char **se_window_argv; /* pre-parsed argument array */ 165 char *se_type; /* default terminal type */ 166 struct init_session *se_prev; 167 struct init_session *se_next; 168} session_t; 169 170static void free_session(session_t *); 171static session_t *new_session(session_t *, struct ttyent *); 172static session_t *sessions; 173 174static char **construct_argv(char *); 175static void start_window_system(session_t *); 176static void collect_child(pid_t); 177static pid_t start_getty(session_t *); 178static void transition_handler(int); 179static void alrm_handler(int); 180static void setsecuritylevel(int); 181static int getsecuritylevel(void); 182static int setupargv(session_t *, struct ttyent *); 183#ifdef LOGIN_CAP 184static void setprocresources(const char *); 185#endif 186static int clang; 187 188static int start_session_db(void); 189static void add_session(session_t *); 190static void del_session(session_t *); 191static session_t *find_session(pid_t); 192static DB *session_db; 193 194/* 195 * The mother of all processes. 196 */ 197int 198main(int argc, char *argv[]) 199{ 200 state_t initial_transition = runcom; 201 char kenv_value[PATH_MAX]; 202 int c, error; 203 struct sigaction sa; 204 sigset_t mask; 205 206 /* Dispose of random users. */ 207 if (getuid() != 0) 208 errx(1, "%s", strerror(EPERM)); 209 210 /* System V users like to reexec init. */ 211 if (getpid() != 1) { 212#ifdef COMPAT_SYSV_INIT 213 /* So give them what they want */ 214 if (argc > 1) { 215 if (strlen(argv[1]) == 1) { 216 char runlevel = *argv[1]; 217 int sig; 218 219 switch (runlevel) { 220 case '0': /* halt + poweroff */ 221 sig = SIGUSR2; 222 break; 223 case '1': /* single-user */ 224 sig = SIGTERM; 225 break; 226 case '6': /* reboot */ 227 sig = SIGINT; 228 break; 229 case 'c': /* block further logins */ 230 sig = SIGTSTP; 231 break; 232 case 'q': /* rescan /etc/ttys */ 233 sig = SIGHUP; 234 break; 235 case 'r': /* remount root */ 236 sig = SIGEMT; 237 break; 238 default: 239 goto invalid; 240 } 241 kill(1, sig); 242 _exit(0); 243 } else 244invalid: 245 errx(1, "invalid run-level ``%s''", argv[1]); 246 } else 247#endif 248 errx(1, "already running"); 249 } 250 251 init_path_argv0 = strdup(argv[0]); 252 if (init_path_argv0 == NULL) 253 err(1, "strdup"); 254 255 /* 256 * Note that this does NOT open a file... 257 * Does 'init' deserve its own facility number? 258 */ 259 openlog("init", LOG_CONS, LOG_AUTH); 260 261 /* 262 * Create an initial session. 263 */ 264 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 265 warning("initial setsid() failed: %m"); 266 267 /* 268 * Establish an initial user so that programs running 269 * single user do not freak out and die (like passwd). 270 */ 271 if (setlogin("root") < 0) 272 warning("setlogin() failed: %m"); 273 274 /* 275 * This code assumes that we always get arguments through flags, 276 * never through bits set in some random machine register. 277 */ 278 while ((c = getopt(argc, argv, "dsfr")) != -1) 279 switch (c) { 280 case 'd': 281 devfs = 1; 282 break; 283 case 's': 284 initial_transition = single_user; 285 break; 286 case 'f': 287 runcom_mode = FASTBOOT; 288 break; 289 case 'r': 290 initial_transition = reroot_phase_two; 291 break; 292 default: 293 warning("unrecognized flag '-%c'", c); 294 break; 295 } 296 297 if (optind != argc) 298 warning("ignoring excess arguments"); 299 300 /* 301 * We catch or block signals rather than ignore them, 302 * so that they get reset on exec. 303 */ 304 handle(badsys, SIGSYS, 0); 305 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 306 SIGXFSZ, 0); 307 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 308 SIGUSR1, SIGUSR2, 0); 309 handle(alrm_handler, SIGALRM, 0); 310 sigfillset(&mask); 311 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 312 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 313 SIGALRM, SIGUSR1, SIGUSR2, 0); 314 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 315 sigemptyset(&sa.sa_mask); 316 sa.sa_flags = 0; 317 sa.sa_handler = SIG_IGN; 318 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 319 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 320 321 /* 322 * Paranoia. 323 */ 324 close(0); 325 close(1); 326 close(2); 327 328 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 329 state_func_t next_transition; 330 331 if ((next_transition = run_script(kenv_value)) != NULL) 332 initial_transition = (state_t) next_transition; 333 } 334 335 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 336 if (chdir(kenv_value) != 0 || chroot(".") != 0) 337 warning("Can't chroot to %s: %m", kenv_value); 338 } 339 340 /* 341 * Additional check if devfs needs to be mounted: 342 * If "/" and "/dev" have the same device number, 343 * then it hasn't been mounted yet. 344 */ 345 if (!devfs) { 346 struct stat stst; 347 dev_t root_devno; 348 349 stat("/", &stst); 350 root_devno = stst.st_dev; 351 if (stat("/dev", &stst) != 0) 352 warning("Can't stat /dev: %m"); 353 else if (stst.st_dev == root_devno) 354 devfs++; 355 } 356 357 if (devfs) { 358 struct iovec iov[4]; 359 char *s; 360 int i; 361 362 char _fstype[] = "fstype"; 363 char _devfs[] = "devfs"; 364 char _fspath[] = "fspath"; 365 char _path_dev[]= _PATH_DEV; 366 367 iov[0].iov_base = _fstype; 368 iov[0].iov_len = sizeof(_fstype); 369 iov[1].iov_base = _devfs; 370 iov[1].iov_len = sizeof(_devfs); 371 iov[2].iov_base = _fspath; 372 iov[2].iov_len = sizeof(_fspath); 373 /* 374 * Try to avoid the trailing slash in _PATH_DEV. 375 * Be *very* defensive. 376 */ 377 s = strdup(_PATH_DEV); 378 if (s != NULL) { 379 i = strlen(s); 380 if (i > 0 && s[i - 1] == '/') 381 s[i - 1] = '\0'; 382 iov[3].iov_base = s; 383 iov[3].iov_len = strlen(s) + 1; 384 } else { 385 iov[3].iov_base = _path_dev; 386 iov[3].iov_len = sizeof(_path_dev); 387 } 388 nmount(iov, 4, 0); 389 if (s != NULL) 390 free(s); 391 } 392 393 if (initial_transition != reroot_phase_two) { 394 /* 395 * Unmount reroot leftovers. This runs after init(8) 396 * gets reexecuted after reroot_phase_two() is done. 397 */ 398 error = unmount(_PATH_REROOT, MNT_FORCE); 399 if (error != 0 && errno != EINVAL) 400 warning("Cannot unmount %s: %m", _PATH_REROOT); 401 } 402 403 /* 404 * Start the state machine. 405 */ 406 transition(initial_transition); 407 408 /* 409 * Should never reach here. 410 */ 411 return 1; 412} 413 414/* 415 * Associate a function with a signal handler. 416 */ 417static void 418handle(sig_t handler, ...) 419{ 420 int sig; 421 struct sigaction sa; 422 sigset_t mask_everything; 423 va_list ap; 424 va_start(ap, handler); 425 426 sa.sa_handler = handler; 427 sigfillset(&mask_everything); 428 429 while ((sig = va_arg(ap, int)) != 0) { 430 sa.sa_mask = mask_everything; 431 /* XXX SA_RESTART? */ 432 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 433 sigaction(sig, &sa, (struct sigaction *) 0); 434 } 435 va_end(ap); 436} 437 438/* 439 * Delete a set of signals from a mask. 440 */ 441static void 442delset(sigset_t *maskp, ...) 443{ 444 int sig; 445 va_list ap; 446 va_start(ap, maskp); 447 448 while ((sig = va_arg(ap, int)) != 0) 449 sigdelset(maskp, sig); 450 va_end(ap); 451} 452 453/* 454 * Log a message and sleep for a while (to give someone an opportunity 455 * to read it and to save log or hardcopy output if the problem is chronic). 456 * NB: should send a message to the session logger to avoid blocking. 457 */ 458static void 459stall(const char *message, ...) 460{ 461 va_list ap; 462 va_start(ap, message); 463 464 vsyslog(LOG_ALERT, message, ap); 465 va_end(ap); 466 sleep(STALL_TIMEOUT); 467} 468 469/* 470 * Like stall(), but doesn't sleep. 471 * If cpp had variadic macros, the two functions could be #defines for another. 472 * NB: should send a message to the session logger to avoid blocking. 473 */ 474static void 475warning(const char *message, ...) 476{ 477 va_list ap; 478 va_start(ap, message); 479 480 vsyslog(LOG_ALERT, message, ap); 481 va_end(ap); 482} 483 484/* 485 * Log an emergency message. 486 * NB: should send a message to the session logger to avoid blocking. 487 */ 488static void 489emergency(const char *message, ...) 490{ 491 va_list ap; 492 va_start(ap, message); 493 494 vsyslog(LOG_EMERG, message, ap); 495 va_end(ap); 496} 497 498/* 499 * Catch a SIGSYS signal. 500 * 501 * These may arise if a system does not support sysctl. 502 * We tolerate up to 25 of these, then throw in the towel. 503 */ 504static void 505badsys(int sig) 506{ 507 static int badcount = 0; 508 509 if (badcount++ < 25) 510 return; 511 disaster(sig); 512} 513 514/* 515 * Catch an unexpected signal. 516 */ 517static void 518disaster(int sig) 519{ 520 521 emergency("fatal signal: %s", 522 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 523 524 sleep(STALL_TIMEOUT); 525 _exit(sig); /* reboot */ 526} 527 528/* 529 * Get the security level of the kernel. 530 */ 531static int 532getsecuritylevel(void) 533{ 534#ifdef KERN_SECURELVL 535 int name[2], curlevel; 536 size_t len; 537 538 name[0] = CTL_KERN; 539 name[1] = KERN_SECURELVL; 540 len = sizeof curlevel; 541 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 542 emergency("cannot get kernel security level: %s", 543 strerror(errno)); 544 return (-1); 545 } 546 return (curlevel); 547#else 548 return (-1); 549#endif 550} 551 552/* 553 * Set the security level of the kernel. 554 */ 555static void 556setsecuritylevel(int newlevel) 557{ 558#ifdef KERN_SECURELVL 559 int name[2], curlevel; 560 561 curlevel = getsecuritylevel(); 562 if (newlevel == curlevel) 563 return; 564 name[0] = CTL_KERN; 565 name[1] = KERN_SECURELVL; 566 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 567 emergency( 568 "cannot change kernel security level from %d to %d: %s", 569 curlevel, newlevel, strerror(errno)); 570 return; 571 } 572#ifdef SECURE 573 warning("kernel security level changed from %d to %d", 574 curlevel, newlevel); 575#endif 576#endif 577} 578 579/* 580 * Change states in the finite state machine. 581 * The initial state is passed as an argument. 582 */ 583static void 584transition(state_t s) 585{ 586 587 current_state = s; 588 for (;;) 589 current_state = (state_t) (*current_state)(); 590} 591 592/* 593 * Start a session and allocate a controlling terminal. 594 * Only called by children of init after forking. 595 */ 596static void 597open_console(void) 598{ 599 int fd; 600 601 /* 602 * Try to open /dev/console. Open the device with O_NONBLOCK to 603 * prevent potential blocking on a carrier. 604 */ 605 revoke(_PATH_CONSOLE); 606 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 607 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 608 if (login_tty(fd) == 0) 609 return; 610 close(fd); 611 } 612 613 /* No luck. Log output to file if possible. */ 614 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 615 stall("cannot open null device."); 616 _exit(1); 617 } 618 if (fd != STDIN_FILENO) { 619 dup2(fd, STDIN_FILENO); 620 close(fd); 621 } 622 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 623 if (fd == -1) 624 dup2(STDIN_FILENO, STDOUT_FILENO); 625 else if (fd != STDOUT_FILENO) { 626 dup2(fd, STDOUT_FILENO); 627 close(fd); 628 } 629 dup2(STDOUT_FILENO, STDERR_FILENO); 630} 631 632static const char * 633get_shell(void) 634{ 635 static char kenv_value[PATH_MAX]; 636 637 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 638 return kenv_value; 639 else 640 return _PATH_BSHELL; 641} 642 643static void 644write_stderr(const char *message) 645{ 646 647 write(STDERR_FILENO, message, strlen(message)); 648} 649 650static int 651read_file(const char *path, void **bufp, size_t *bufsizep) 652{ 653 struct stat sb; 654 size_t bufsize; 655 void *buf; 656 ssize_t nbytes; 657 int error, fd; 658 659 fd = open(path, O_RDONLY); 660 if (fd < 0) { 661 emergency("%s: %s", path, strerror(errno)); 662 return (-1); 663 } 664 665 error = fstat(fd, &sb); 666 if (error != 0) { 667 emergency("fstat: %s", strerror(errno)); 668 close(fd); 669 return (error); 670 } 671 672 bufsize = sb.st_size; 673 buf = malloc(bufsize); 674 if (buf == NULL) { 675 emergency("malloc: %s", strerror(errno)); 676 close(fd); 677 return (error); 678 } 679 680 nbytes = read(fd, buf, bufsize); 681 if (nbytes != (ssize_t)bufsize) { 682 emergency("read: %s", strerror(errno)); 683 close(fd); 684 free(buf); 685 return (error); 686 } 687 688 error = close(fd); 689 if (error != 0) { 690 emergency("close: %s", strerror(errno)); 691 free(buf); 692 return (error); 693 } 694 695 *bufp = buf; 696 *bufsizep = bufsize; 697 698 return (0); 699} 700 701static int 702create_file(const char *path, const void *buf, size_t bufsize) 703{ 704 ssize_t nbytes; 705 int error, fd; 706 707 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 708 if (fd < 0) { 709 emergency("%s: %s", path, strerror(errno)); 710 return (-1); 711 } 712 713 nbytes = write(fd, buf, bufsize); 714 if (nbytes != (ssize_t)bufsize) { 715 emergency("write: %s", strerror(errno)); 716 close(fd); 717 return (-1); 718 } 719 720 error = close(fd); 721 if (error != 0) { 722 emergency("close: %s", strerror(errno)); 723 return (-1); 724 } 725 726 return (0); 727} 728 729static int 730mount_tmpfs(const char *fspath) 731{ 732 struct iovec *iov; 733 char errmsg[255]; 734 int error, iovlen; 735 736 iov = NULL; 737 iovlen = 0; 738 memset(errmsg, 0, sizeof(errmsg)); 739 build_iovec(&iov, &iovlen, "fstype", 740 __DECONST(void *, "tmpfs"), (size_t)-1); 741 build_iovec(&iov, &iovlen, "fspath", 742 __DECONST(void *, fspath), (size_t)-1); 743 build_iovec(&iov, &iovlen, "errmsg", 744 errmsg, sizeof(errmsg)); 745 746 error = nmount(iov, iovlen, 0); 747 if (error != 0) { 748 if (*errmsg != '\0') { 749 emergency("cannot mount tmpfs on %s: %s: %s", 750 fspath, errmsg, strerror(errno)); 751 } else { 752 emergency("cannot mount tmpfs on %s: %s", 753 fspath, strerror(errno)); 754 } 755 return (error); 756 } 757 return (0); 758} 759 760static state_func_t 761reroot(void) 762{ 763 void *buf; 764 size_t bufsize; 765 int error; 766 767 buf = NULL; 768 bufsize = 0; 769 770 revoke_ttys(); 771 runshutdown(); 772 773 /* 774 * Make sure nobody can interfere with our scheme. 775 * Ignore ESRCH, which can apparently happen when 776 * there are no processes to kill. 777 */ 778 error = kill(-1, SIGKILL); 779 if (error != 0 && errno != ESRCH) { 780 emergency("kill(2) failed: %s", strerror(errno)); 781 goto out; 782 } 783 784 /* 785 * Copy the init binary into tmpfs, so that we can unmount 786 * the old rootfs without committing suicide. 787 */ 788 error = read_file(init_path_argv0, &buf, &bufsize); 789 if (error != 0) 790 goto out; 791 error = mount_tmpfs(_PATH_REROOT); 792 if (error != 0) 793 goto out; 794 error = create_file(_PATH_REROOT_INIT, buf, bufsize); 795 if (error != 0) 796 goto out; 797 798 /* 799 * Execute the temporary init. 800 */ 801 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); 802 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno)); 803 804out: 805 emergency("reroot failed; going to single user mode"); 806 free(buf); 807 return (state_func_t) single_user; 808} 809 810static state_func_t 811reroot_phase_two(void) 812{ 813 char init_path[PATH_MAX], *path, *path_component; 814 size_t init_path_len; 815 int nbytes, error; 816 817 /* 818 * Ask the kernel to mount the new rootfs. 819 */ 820 error = reboot(RB_REROOT); 821 if (error != 0) { 822 emergency("RB_REBOOT failed: %s", strerror(errno)); 823 goto out; 824 } 825 826 /* 827 * Figure out where the destination init(8) binary is. Note that 828 * the path could be different than what we've started with. Use 829 * the value from kenv, if set, or the one from sysctl otherwise. 830 * The latter defaults to a hardcoded value, but can be overridden 831 * by a build time option. 832 */ 833 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 834 if (nbytes <= 0) { 835 init_path_len = sizeof(init_path); 836 error = sysctlbyname("kern.init_path", 837 init_path, &init_path_len, NULL, 0); 838 if (error != 0) { 839 emergency("failed to retrieve kern.init_path: %s", 840 strerror(errno)); 841 goto out; 842 } 843 } 844 845 /* 846 * Repeat the init search logic from sys/kern/init_path.c 847 */ 848 path_component = init_path; 849 while ((path = strsep(&path_component, ":")) != NULL) { 850 /* 851 * Execute init(8) from the new rootfs. 852 */ 853 execl(path, path, NULL); 854 } 855 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 856 857out: 858 emergency("reroot failed; going to single user mode"); 859 return (state_func_t) single_user; 860} 861 862/* 863 * Bring the system up single user. 864 */ 865static state_func_t 866single_user(void) 867{ 868 pid_t pid, wpid; 869 int status; 870 sigset_t mask; 871 const char *shell; 872 char *argv[2]; 873 struct timeval tv, tn; 874#ifdef SECURE 875 struct ttyent *typ; 876 struct passwd *pp; 877 static const char banner[] = 878 "Enter root password, or ^D to go multi-user\n"; 879 char *clear, *password; 880#endif 881#ifdef DEBUGSHELL 882 char altshell[128]; 883#endif 884 885 if (Reboot) { 886 /* Instead of going single user, let's reboot the machine */ 887 sync(); 888 if (reboot(howto) == -1) { 889 emergency("reboot(%#x) failed, %s", howto, 890 strerror(errno)); 891 _exit(1); /* panic and reboot */ 892 } 893 warning("reboot(%#x) returned", howto); 894 _exit(0); /* panic as well */ 895 } 896 897 shell = get_shell(); 898 899 if ((pid = fork()) == 0) { 900 /* 901 * Start the single user session. 902 */ 903 open_console(); 904 905#ifdef SECURE 906 /* 907 * Check the root password. 908 * We don't care if the console is 'on' by default; 909 * it's the only tty that can be 'off' and 'secure'. 910 */ 911 typ = getttynam("console"); 912 pp = getpwnam("root"); 913 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 914 pp && *pp->pw_passwd) { 915 write_stderr(banner); 916 for (;;) { 917 clear = getpass("Password:"); 918 if (clear == NULL || *clear == '\0') 919 _exit(0); 920 password = crypt(clear, pp->pw_passwd); 921 bzero(clear, _PASSWORD_LEN); 922 if (password == NULL || 923 strcmp(password, pp->pw_passwd) == 0) 924 break; 925 warning("single-user login failed\n"); 926 } 927 } 928 endttyent(); 929 endpwent(); 930#endif /* SECURE */ 931 932#ifdef DEBUGSHELL 933 { 934 char *cp = altshell; 935 int num; 936 937#define SHREQUEST "Enter full pathname of shell or RETURN for " 938 write_stderr(SHREQUEST); 939 write_stderr(shell); 940 write_stderr(": "); 941 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 942 num != 0 && *cp != '\n' && cp < &altshell[127]) 943 cp++; 944 *cp = '\0'; 945 if (altshell[0] != '\0') 946 shell = altshell; 947 } 948#endif /* DEBUGSHELL */ 949 950 /* 951 * Unblock signals. 952 * We catch all the interesting ones, 953 * and those are reset to SIG_DFL on exec. 954 */ 955 sigemptyset(&mask); 956 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 957 958 /* 959 * Fire off a shell. 960 * If the default one doesn't work, try the Bourne shell. 961 */ 962 963 char name[] = "-sh"; 964 965 argv[0] = name; 966 argv[1] = 0; 967 execv(shell, argv); 968 emergency("can't exec %s for single user: %m", shell); 969 execv(_PATH_BSHELL, argv); 970 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 971 sleep(STALL_TIMEOUT); 972 _exit(1); 973 } 974 975 if (pid == -1) { 976 /* 977 * We are seriously hosed. Do our best. 978 */ 979 emergency("can't fork single-user shell, trying again"); 980 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 981 continue; 982 return (state_func_t) single_user; 983 } 984 985 requested_transition = 0; 986 do { 987 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 988 collect_child(wpid); 989 if (wpid == -1) { 990 if (errno == EINTR) 991 continue; 992 warning("wait for single-user shell failed: %m; restarting"); 993 return (state_func_t) single_user; 994 } 995 if (wpid == pid && WIFSTOPPED(status)) { 996 warning("init: shell stopped, restarting\n"); 997 kill(pid, SIGCONT); 998 wpid = -1; 999 } 1000 } while (wpid != pid && !requested_transition); 1001 1002 if (requested_transition) 1003 return (state_func_t) requested_transition; 1004 1005 if (!WIFEXITED(status)) { 1006 if (WTERMSIG(status) == SIGKILL) { 1007 /* 1008 * reboot(8) killed shell? 1009 */ 1010 warning("single user shell terminated."); 1011 gettimeofday(&tv, NULL); 1012 tn = tv; 1013 tv.tv_sec += STALL_TIMEOUT; 1014 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == 1015 tn.tv_sec && tv.tv_usec > tn.tv_usec)) { 1016 sleep(1); 1017 gettimeofday(&tn, NULL); 1018 } 1019 _exit(0); 1020 } else { 1021 warning("single user shell terminated, restarting"); 1022 return (state_func_t) single_user; 1023 } 1024 } 1025 1026 runcom_mode = FASTBOOT; 1027 return (state_func_t) runcom; 1028} 1029 1030/* 1031 * Run the system startup script. 1032 */ 1033static state_func_t 1034runcom(void) 1035{ 1036 state_func_t next_transition; 1037 1038 if ((next_transition = run_script(_PATH_RUNCOM)) != NULL) 1039 return next_transition; 1040 1041 runcom_mode = AUTOBOOT; /* the default */ 1042 return (state_func_t) read_ttys; 1043} 1044 1045/* 1046 * Run a shell script. 1047 * Returns 0 on success, otherwise the next transition to enter: 1048 * - single_user if fork/execv/waitpid failed, or if the script 1049 * terminated with a signal or exit code != 0. 1050 * - death_single if a SIGTERM was delivered to init(8). 1051 */ 1052static state_func_t 1053run_script(const char *script) 1054{ 1055 pid_t pid, wpid; 1056 int status; 1057 char *argv[4]; 1058 const char *shell; 1059 struct sigaction sa; 1060 1061 shell = get_shell(); 1062 1063 if ((pid = fork()) == 0) { 1064 sigemptyset(&sa.sa_mask); 1065 sa.sa_flags = 0; 1066 sa.sa_handler = SIG_IGN; 1067 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1068 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1069 1070 open_console(); 1071 1072 char _sh[] = "sh"; 1073 char _autoboot[] = "autoboot"; 1074 1075 argv[0] = _sh; 1076 argv[1] = __DECONST(char *, script); 1077 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1078 argv[3] = 0; 1079 1080 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1081 1082#ifdef LOGIN_CAP 1083 setprocresources(RESOURCE_RC); 1084#endif 1085 execv(shell, argv); 1086 stall("can't exec %s for %s: %m", shell, script); 1087 _exit(1); /* force single user mode */ 1088 } 1089 1090 if (pid == -1) { 1091 emergency("can't fork for %s on %s: %m", shell, script); 1092 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1093 continue; 1094 sleep(STALL_TIMEOUT); 1095 return (state_func_t) single_user; 1096 } 1097 1098 /* 1099 * Copied from single_user(). This is a bit paranoid. 1100 */ 1101 requested_transition = 0; 1102 do { 1103 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1104 collect_child(wpid); 1105 if (wpid == -1) { 1106 if (requested_transition == death_single || 1107 requested_transition == reroot) 1108 return (state_func_t) requested_transition; 1109 if (errno == EINTR) 1110 continue; 1111 warning("wait for %s on %s failed: %m; going to " 1112 "single user mode", shell, script); 1113 return (state_func_t) single_user; 1114 } 1115 if (wpid == pid && WIFSTOPPED(status)) { 1116 warning("init: %s on %s stopped, restarting\n", 1117 shell, script); 1118 kill(pid, SIGCONT); 1119 wpid = -1; 1120 } 1121 } while (wpid != pid); 1122 1123 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1124 requested_transition == catatonia) { 1125 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1126 sigset_t s; 1127 1128 sigfillset(&s); 1129 for (;;) 1130 sigsuspend(&s); 1131 } 1132 1133 if (!WIFEXITED(status)) { 1134 warning("%s on %s terminated abnormally, going to single " 1135 "user mode", shell, script); 1136 return (state_func_t) single_user; 1137 } 1138 1139 if (WEXITSTATUS(status)) 1140 return (state_func_t) single_user; 1141 1142 return (state_func_t) 0; 1143} 1144 1145/* 1146 * Open the session database. 1147 * 1148 * NB: We could pass in the size here; is it necessary? 1149 */ 1150static int 1151start_session_db(void) 1152{ 1153 if (session_db && (*session_db->close)(session_db)) 1154 emergency("session database close: %s", strerror(errno)); 1155 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) { 1156 emergency("session database open: %s", strerror(errno)); 1157 return (1); 1158 } 1159 return (0); 1160 1161} 1162 1163/* 1164 * Add a new login session. 1165 */ 1166static void 1167add_session(session_t *sp) 1168{ 1169 DBT key; 1170 DBT data; 1171 1172 key.data = &sp->se_process; 1173 key.size = sizeof sp->se_process; 1174 data.data = &sp; 1175 data.size = sizeof sp; 1176 1177 if ((*session_db->put)(session_db, &key, &data, 0)) 1178 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1179} 1180 1181/* 1182 * Delete an old login session. 1183 */ 1184static void 1185del_session(session_t *sp) 1186{ 1187 DBT key; 1188 1189 key.data = &sp->se_process; 1190 key.size = sizeof sp->se_process; 1191 1192 if ((*session_db->del)(session_db, &key, 0)) 1193 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1194} 1195 1196/* 1197 * Look up a login session by pid. 1198 */ 1199static session_t * 1200find_session(pid_t pid) 1201{ 1202 DBT key; 1203 DBT data; 1204 session_t *ret; 1205 1206 key.data = &pid; 1207 key.size = sizeof pid; 1208 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1209 return 0; 1210 bcopy(data.data, (char *)&ret, sizeof(ret)); 1211 return ret; 1212} 1213 1214/* 1215 * Construct an argument vector from a command line. 1216 */ 1217static char ** 1218construct_argv(char *command) 1219{ 1220 int argc = 0; 1221 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1222 * sizeof (char *)); 1223 1224 if ((argv[argc++] = strk(command)) == NULL) { 1225 free(argv); 1226 return (NULL); 1227 } 1228 while ((argv[argc++] = strk((char *) 0)) != NULL) 1229 continue; 1230 return argv; 1231} 1232 1233/* 1234 * Deallocate a session descriptor. 1235 */ 1236static void 1237free_session(session_t *sp) 1238{ 1239 free(sp->se_device); 1240 if (sp->se_getty) { 1241 free(sp->se_getty); 1242 free(sp->se_getty_argv_space); 1243 free(sp->se_getty_argv); 1244 } 1245 if (sp->se_window) { 1246 free(sp->se_window); 1247 free(sp->se_window_argv_space); 1248 free(sp->se_window_argv); 1249 } 1250 if (sp->se_type) 1251 free(sp->se_type); 1252 free(sp); 1253} 1254 1255/* 1256 * Allocate a new session descriptor. 1257 * Mark it SE_PRESENT. 1258 */ 1259static session_t * 1260new_session(session_t *sprev, struct ttyent *typ) 1261{ 1262 session_t *sp; 1263 int fd; 1264 1265 if ((typ->ty_status & TTY_ON) == 0 || 1266 typ->ty_name == 0 || 1267 typ->ty_getty == 0) 1268 return 0; 1269 1270 sp = (session_t *) calloc(1, sizeof (session_t)); 1271 1272 sp->se_flags |= SE_PRESENT; 1273 1274 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 1275 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 1276 1277 /* 1278 * Attempt to open the device, if we get "device not configured" 1279 * then don't add the device to the session list. 1280 */ 1281 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) { 1282 if (errno == ENXIO) { 1283 free_session(sp); 1284 return (0); 1285 } 1286 } else 1287 close(fd); 1288 1289 if (setupargv(sp, typ) == 0) { 1290 free_session(sp); 1291 return (0); 1292 } 1293 1294 sp->se_next = 0; 1295 if (sprev == NULL) { 1296 sessions = sp; 1297 sp->se_prev = 0; 1298 } else { 1299 sprev->se_next = sp; 1300 sp->se_prev = sprev; 1301 } 1302 1303 return sp; 1304} 1305 1306/* 1307 * Calculate getty and if useful window argv vectors. 1308 */ 1309static int 1310setupargv(session_t *sp, struct ttyent *typ) 1311{ 1312 1313 if (sp->se_getty) { 1314 free(sp->se_getty); 1315 free(sp->se_getty_argv_space); 1316 free(sp->se_getty_argv); 1317 } 1318 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 1319 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 1320 sp->se_getty_argv_space = strdup(sp->se_getty); 1321 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1322 if (sp->se_getty_argv == NULL) { 1323 warning("can't parse getty for port %s", sp->se_device); 1324 free(sp->se_getty); 1325 free(sp->se_getty_argv_space); 1326 sp->se_getty = sp->se_getty_argv_space = 0; 1327 return (0); 1328 } 1329 if (sp->se_window) { 1330 free(sp->se_window); 1331 free(sp->se_window_argv_space); 1332 free(sp->se_window_argv); 1333 } 1334 sp->se_window = sp->se_window_argv_space = 0; 1335 sp->se_window_argv = 0; 1336 if (typ->ty_window) { 1337 sp->se_window = strdup(typ->ty_window); 1338 sp->se_window_argv_space = strdup(sp->se_window); 1339 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1340 if (sp->se_window_argv == NULL) { 1341 warning("can't parse window for port %s", 1342 sp->se_device); 1343 free(sp->se_window_argv_space); 1344 free(sp->se_window); 1345 sp->se_window = sp->se_window_argv_space = 0; 1346 return (0); 1347 } 1348 } 1349 if (sp->se_type) 1350 free(sp->se_type); 1351 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1352 return (1); 1353} 1354 1355/* 1356 * Walk the list of ttys and create sessions for each active line. 1357 */ 1358static state_func_t 1359read_ttys(void) 1360{ 1361 session_t *sp, *snext; 1362 struct ttyent *typ; 1363 1364 /* 1365 * Destroy any previous session state. 1366 * There shouldn't be any, but just in case... 1367 */ 1368 for (sp = sessions; sp; sp = snext) { 1369 snext = sp->se_next; 1370 free_session(sp); 1371 } 1372 sessions = 0; 1373 if (start_session_db()) 1374 return (state_func_t) single_user; 1375 1376 /* 1377 * Allocate a session entry for each active port. 1378 * Note that sp starts at 0. 1379 */ 1380 while ((typ = getttyent()) != NULL) 1381 if ((snext = new_session(sp, typ)) != NULL) 1382 sp = snext; 1383 1384 endttyent(); 1385 1386 return (state_func_t) multi_user; 1387} 1388 1389/* 1390 * Start a window system running. 1391 */ 1392static void 1393start_window_system(session_t *sp) 1394{ 1395 pid_t pid; 1396 sigset_t mask; 1397 char term[64], *env[2]; 1398 int status; 1399 1400 if ((pid = fork()) == -1) { 1401 emergency("can't fork for window system on port %s: %m", 1402 sp->se_device); 1403 /* hope that getty fails and we can try again */ 1404 return; 1405 } 1406 if (pid) { 1407 waitpid(-1, &status, 0); 1408 return; 1409 } 1410 1411 /* reparent window process to the init to not make a zombie on exit */ 1412 if ((pid = fork()) == -1) { 1413 emergency("can't fork for window system on port %s: %m", 1414 sp->se_device); 1415 _exit(1); 1416 } 1417 if (pid) 1418 _exit(0); 1419 1420 sigemptyset(&mask); 1421 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1422 1423 if (setsid() < 0) 1424 emergency("setsid failed (window) %m"); 1425 1426#ifdef LOGIN_CAP 1427 setprocresources(RESOURCE_WINDOW); 1428#endif 1429 if (sp->se_type) { 1430 /* Don't use malloc after fork */ 1431 strcpy(term, "TERM="); 1432 strncat(term, sp->se_type, sizeof(term) - 6); 1433 env[0] = term; 1434 env[1] = 0; 1435 } 1436 else 1437 env[0] = 0; 1438 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1439 stall("can't exec window system '%s' for port %s: %m", 1440 sp->se_window_argv[0], sp->se_device); 1441 _exit(1); 1442} 1443 1444/* 1445 * Start a login session running. 1446 */ 1447static pid_t 1448start_getty(session_t *sp) 1449{ 1450 pid_t pid; 1451 sigset_t mask; 1452 time_t current_time = time((time_t *) 0); 1453 int too_quick = 0; 1454 char term[64], *env[2]; 1455 1456 if (current_time >= sp->se_started && 1457 current_time - sp->se_started < GETTY_SPACING) { 1458 if (++sp->se_nspace > GETTY_NSPACE) { 1459 sp->se_nspace = 0; 1460 too_quick = 1; 1461 } 1462 } else 1463 sp->se_nspace = 0; 1464 1465 /* 1466 * fork(), not vfork() -- we can't afford to block. 1467 */ 1468 if ((pid = fork()) == -1) { 1469 emergency("can't fork for getty on port %s: %m", sp->se_device); 1470 return -1; 1471 } 1472 1473 if (pid) 1474 return pid; 1475 1476 if (too_quick) { 1477 warning("getty repeating too quickly on port %s, sleeping %d secs", 1478 sp->se_device, GETTY_SLEEP); 1479 sleep((unsigned) GETTY_SLEEP); 1480 } 1481 1482 if (sp->se_window) { 1483 start_window_system(sp); 1484 sleep(WINDOW_WAIT); 1485 } 1486 1487 sigemptyset(&mask); 1488 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1489 1490#ifdef LOGIN_CAP 1491 setprocresources(RESOURCE_GETTY); 1492#endif 1493 if (sp->se_type) { 1494 /* Don't use malloc after fork */ 1495 strcpy(term, "TERM="); 1496 strncat(term, sp->se_type, sizeof(term) - 6); 1497 env[0] = term; 1498 env[1] = 0; 1499 } else 1500 env[0] = 0; 1501 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1502 stall("can't exec getty '%s' for port %s: %m", 1503 sp->se_getty_argv[0], sp->se_device); 1504 _exit(1); 1505} 1506 1507/* 1508 * Collect exit status for a child. 1509 * If an exiting login, start a new login running. 1510 */ 1511static void 1512collect_child(pid_t pid) 1513{ 1514 session_t *sp, *sprev, *snext; 1515 1516 if (! sessions) 1517 return; 1518 1519 if (! (sp = find_session(pid))) 1520 return; 1521 1522 del_session(sp); 1523 sp->se_process = 0; 1524 1525 if (sp->se_flags & SE_SHUTDOWN) { 1526 if ((sprev = sp->se_prev) != NULL) 1527 sprev->se_next = sp->se_next; 1528 else 1529 sessions = sp->se_next; 1530 if ((snext = sp->se_next) != NULL) 1531 snext->se_prev = sp->se_prev; 1532 free_session(sp); 1533 return; 1534 } 1535 1536 if ((pid = start_getty(sp)) == -1) { 1537 /* serious trouble */ 1538 requested_transition = clean_ttys; 1539 return; 1540 } 1541 1542 sp->se_process = pid; 1543 sp->se_started = time((time_t *) 0); 1544 add_session(sp); 1545} 1546 1547/* 1548 * Catch a signal and request a state transition. 1549 */ 1550static void 1551transition_handler(int sig) 1552{ 1553 1554 switch (sig) { 1555 case SIGHUP: 1556 if (current_state == read_ttys || current_state == multi_user || 1557 current_state == clean_ttys || current_state == catatonia) 1558 requested_transition = clean_ttys; 1559 break; 1560 case SIGUSR2: 1561 howto = RB_POWEROFF; 1562 case SIGUSR1: 1563 howto |= RB_HALT; 1564 case SIGINT: 1565 Reboot = TRUE; 1566 case SIGTERM: 1567 if (current_state == read_ttys || current_state == multi_user || 1568 current_state == clean_ttys || current_state == catatonia) 1569 requested_transition = death; 1570 else 1571 requested_transition = death_single; 1572 break; 1573 case SIGTSTP: 1574 if (current_state == runcom || current_state == read_ttys || 1575 current_state == clean_ttys || 1576 current_state == multi_user || current_state == catatonia) 1577 requested_transition = catatonia; 1578 break; 1579 case SIGEMT: 1580 requested_transition = reroot; 1581 break; 1582 default: 1583 requested_transition = 0; 1584 break; 1585 } 1586} 1587 1588/* 1589 * Take the system multiuser. 1590 */ 1591static state_func_t 1592multi_user(void) 1593{ 1594 pid_t pid; 1595 session_t *sp; 1596 1597 requested_transition = 0; 1598 1599 /* 1600 * If the administrator has not set the security level to -1 1601 * to indicate that the kernel should not run multiuser in secure 1602 * mode, and the run script has not set a higher level of security 1603 * than level 1, then put the kernel into secure mode. 1604 */ 1605 if (getsecuritylevel() == 0) 1606 setsecuritylevel(1); 1607 1608 for (sp = sessions; sp; sp = sp->se_next) { 1609 if (sp->se_process) 1610 continue; 1611 if ((pid = start_getty(sp)) == -1) { 1612 /* serious trouble */ 1613 requested_transition = clean_ttys; 1614 break; 1615 } 1616 sp->se_process = pid; 1617 sp->se_started = time((time_t *) 0); 1618 add_session(sp); 1619 } 1620 1621 while (!requested_transition) 1622 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1623 collect_child(pid); 1624 1625 return (state_func_t) requested_transition; 1626} 1627 1628/* 1629 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1630 */ 1631static state_func_t 1632clean_ttys(void) 1633{ 1634 session_t *sp, *sprev; 1635 struct ttyent *typ; 1636 int devlen; 1637 char *old_getty, *old_window, *old_type; 1638 1639 /* 1640 * mark all sessions for death, (!SE_PRESENT) 1641 * as we find or create new ones they'll be marked as keepers, 1642 * we'll later nuke all the ones not found in /etc/ttys 1643 */ 1644 for (sp = sessions; sp != NULL; sp = sp->se_next) 1645 sp->se_flags &= ~SE_PRESENT; 1646 1647 devlen = sizeof(_PATH_DEV) - 1; 1648 while ((typ = getttyent()) != NULL) { 1649 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1650 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1651 break; 1652 1653 if (sp) { 1654 /* we want this one to live */ 1655 sp->se_flags |= SE_PRESENT; 1656 if ((typ->ty_status & TTY_ON) == 0 || 1657 typ->ty_getty == 0) { 1658 sp->se_flags |= SE_SHUTDOWN; 1659 kill(sp->se_process, SIGHUP); 1660 continue; 1661 } 1662 sp->se_flags &= ~SE_SHUTDOWN; 1663 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1664 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1665 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1666 if (setupargv(sp, typ) == 0) { 1667 warning("can't parse getty for port %s", 1668 sp->se_device); 1669 sp->se_flags |= SE_SHUTDOWN; 1670 kill(sp->se_process, SIGHUP); 1671 } 1672 else if ( !old_getty 1673 || (!old_type && sp->se_type) 1674 || (old_type && !sp->se_type) 1675 || (!old_window && sp->se_window) 1676 || (old_window && !sp->se_window) 1677 || (strcmp(old_getty, sp->se_getty) != 0) 1678 || (old_window && strcmp(old_window, sp->se_window) != 0) 1679 || (old_type && strcmp(old_type, sp->se_type) != 0) 1680 ) { 1681 /* Don't set SE_SHUTDOWN here */ 1682 sp->se_nspace = 0; 1683 sp->se_started = 0; 1684 kill(sp->se_process, SIGHUP); 1685 } 1686 if (old_getty) 1687 free(old_getty); 1688 if (old_window) 1689 free(old_window); 1690 if (old_type) 1691 free(old_type); 1692 continue; 1693 } 1694 1695 new_session(sprev, typ); 1696 } 1697 1698 endttyent(); 1699 1700 /* 1701 * sweep through and kill all deleted sessions 1702 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1703 */ 1704 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1705 if ((sp->se_flags & SE_PRESENT) == 0) { 1706 sp->se_flags |= SE_SHUTDOWN; 1707 kill(sp->se_process, SIGHUP); 1708 } 1709 } 1710 1711 return (state_func_t) multi_user; 1712} 1713 1714/* 1715 * Block further logins. 1716 */ 1717static state_func_t 1718catatonia(void) 1719{ 1720 session_t *sp; 1721 1722 for (sp = sessions; sp; sp = sp->se_next) 1723 sp->se_flags |= SE_SHUTDOWN; 1724 1725 return (state_func_t) multi_user; 1726} 1727 1728/* 1729 * Note SIGALRM. 1730 */ 1731static void 1732alrm_handler(int sig) 1733{ 1734 1735 (void)sig; 1736 clang = 1; 1737} 1738 1739/* 1740 * Bring the system down to single user. 1741 */ 1742static state_func_t 1743death(void) 1744{ 1745 int block, blocked; 1746 size_t len; 1747 1748 /* Temporarily block suspend. */ 1749 len = sizeof(blocked); 1750 block = 1; 1751 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1752 &block, sizeof(block)) == -1) 1753 blocked = 0; 1754 1755 /* 1756 * Also revoke the TTY here. Because runshutdown() may reopen 1757 * the TTY whose getty we're killing here, there is no guarantee 1758 * runshutdown() will perform the initial open() call, causing 1759 * the terminal attributes to be misconfigured. 1760 */ 1761 revoke_ttys(); 1762 1763 /* Try to run the rc.shutdown script within a period of time */ 1764 runshutdown(); 1765 1766 /* Unblock suspend if we blocked it. */ 1767 if (!blocked) 1768 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1769 &blocked, sizeof(blocked)); 1770 1771 return (state_func_t) death_single; 1772} 1773 1774/* 1775 * Do what is necessary to reinitialize single user mode or reboot 1776 * from an incomplete state. 1777 */ 1778static state_func_t 1779death_single(void) 1780{ 1781 int i; 1782 pid_t pid; 1783 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1784 1785 revoke(_PATH_CONSOLE); 1786 1787 for (i = 0; i < 2; ++i) { 1788 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1789 return (state_func_t) single_user; 1790 1791 clang = 0; 1792 alarm(DEATH_WATCH); 1793 do 1794 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1795 collect_child(pid); 1796 while (clang == 0 && errno != ECHILD); 1797 1798 if (errno == ECHILD) 1799 return (state_func_t) single_user; 1800 } 1801 1802 warning("some processes would not die; ps axl advised"); 1803 1804 return (state_func_t) single_user; 1805} 1806 1807static void 1808revoke_ttys(void) 1809{ 1810 session_t *sp; 1811 1812 for (sp = sessions; sp; sp = sp->se_next) { 1813 sp->se_flags |= SE_SHUTDOWN; 1814 kill(sp->se_process, SIGHUP); 1815 revoke(sp->se_device); 1816 } 1817} 1818 1819/* 1820 * Run the system shutdown script. 1821 * 1822 * Exit codes: XXX I should document more 1823 * -2 shutdown script terminated abnormally 1824 * -1 fatal error - can't run script 1825 * 0 good. 1826 * >0 some error (exit code) 1827 */ 1828static int 1829runshutdown(void) 1830{ 1831 pid_t pid, wpid; 1832 int status; 1833 int shutdowntimeout; 1834 size_t len; 1835 char *argv[4]; 1836 const char *shell; 1837 struct sigaction sa; 1838 struct stat sb; 1839 1840 /* 1841 * rc.shutdown is optional, so to prevent any unnecessary 1842 * complaints from the shell we simply don't run it if the 1843 * file does not exist. If the stat() here fails for other 1844 * reasons, we'll let the shell complain. 1845 */ 1846 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1847 return 0; 1848 1849 shell = get_shell(); 1850 1851 if ((pid = fork()) == 0) { 1852 sigemptyset(&sa.sa_mask); 1853 sa.sa_flags = 0; 1854 sa.sa_handler = SIG_IGN; 1855 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1856 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1857 1858 open_console(); 1859 1860 char _sh[] = "sh"; 1861 char _reboot[] = "reboot"; 1862 char _single[] = "single"; 1863 char _path_rundown[] = _PATH_RUNDOWN; 1864 1865 argv[0] = _sh; 1866 argv[1] = _path_rundown; 1867 argv[2] = Reboot ? _reboot : _single; 1868 argv[3] = 0; 1869 1870 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1871 1872#ifdef LOGIN_CAP 1873 setprocresources(RESOURCE_RC); 1874#endif 1875 execv(shell, argv); 1876 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1877 _exit(1); /* force single user mode */ 1878 } 1879 1880 if (pid == -1) { 1881 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1882 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1883 continue; 1884 sleep(STALL_TIMEOUT); 1885 return -1; 1886 } 1887 1888 len = sizeof(shutdowntimeout); 1889 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1890 NULL, 0) == -1 || shutdowntimeout < 2) 1891 shutdowntimeout = DEATH_SCRIPT; 1892 alarm(shutdowntimeout); 1893 clang = 0; 1894 /* 1895 * Copied from single_user(). This is a bit paranoid. 1896 * Use the same ALRM handler. 1897 */ 1898 do { 1899 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1900 collect_child(wpid); 1901 if (clang == 1) { 1902 /* we were waiting for the sub-shell */ 1903 kill(wpid, SIGTERM); 1904 warning("timeout expired for %s on %s: %m; going to " 1905 "single user mode", shell, _PATH_RUNDOWN); 1906 return -1; 1907 } 1908 if (wpid == -1) { 1909 if (errno == EINTR) 1910 continue; 1911 warning("wait for %s on %s failed: %m; going to " 1912 "single user mode", shell, _PATH_RUNDOWN); 1913 return -1; 1914 } 1915 if (wpid == pid && WIFSTOPPED(status)) { 1916 warning("init: %s on %s stopped, restarting\n", 1917 shell, _PATH_RUNDOWN); 1918 kill(pid, SIGCONT); 1919 wpid = -1; 1920 } 1921 } while (wpid != pid && !clang); 1922 1923 /* Turn off the alarm */ 1924 alarm(0); 1925 1926 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1927 requested_transition == catatonia) { 1928 /* 1929 * /etc/rc.shutdown executed /sbin/reboot; 1930 * wait for the end quietly 1931 */ 1932 sigset_t s; 1933 1934 sigfillset(&s); 1935 for (;;) 1936 sigsuspend(&s); 1937 } 1938 1939 if (!WIFEXITED(status)) { 1940 warning("%s on %s terminated abnormally, going to " 1941 "single user mode", shell, _PATH_RUNDOWN); 1942 return -2; 1943 } 1944 1945 if ((status = WEXITSTATUS(status)) != 0) 1946 warning("%s returned status %d", _PATH_RUNDOWN, status); 1947 1948 return status; 1949} 1950 1951static char * 1952strk(char *p) 1953{ 1954 static char *t; 1955 char *q; 1956 int c; 1957 1958 if (p) 1959 t = p; 1960 if (!t) 1961 return 0; 1962 1963 c = *t; 1964 while (c == ' ' || c == '\t' ) 1965 c = *++t; 1966 if (!c) { 1967 t = 0; 1968 return 0; 1969 } 1970 q = t; 1971 if (c == '\'') { 1972 c = *++t; 1973 q = t; 1974 while (c && c != '\'') 1975 c = *++t; 1976 if (!c) /* unterminated string */ 1977 q = t = 0; 1978 else 1979 *t++ = 0; 1980 } else { 1981 while (c && c != ' ' && c != '\t' ) 1982 c = *++t; 1983 *t++ = 0; 1984 if (!c) 1985 t = 0; 1986 } 1987 return q; 1988} 1989 1990#ifdef LOGIN_CAP 1991static void 1992setprocresources(const char *cname) 1993{ 1994 login_cap_t *lc; 1995 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 1996 setusercontext(lc, (struct passwd*)NULL, 0, 1997 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 1998 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 1999 login_close(lc); 2000 } 2001} 2002#endif 2003