init.c revision 293744
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/10/sbin/init/init.c 293744 2016-01-12 10:14:57Z trasz $"; 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; 141 142static void transition(state_t); 143static state_t requested_transition; 144static state_t current_state = death_single; 145 146static void open_console(void); 147static const char *get_shell(void); 148static void write_stderr(const char *message); 149 150typedef struct init_session { 151 int se_index; /* index of entry in ttys file */ 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 *, int, 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 * Note that this does NOT open a file... 252 * Does 'init' deserve its own facility number? 253 */ 254 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH); 255 256 /* 257 * Create an initial session. 258 */ 259 if (setsid() < 0 && (errno != EPERM || getsid(0) != 1)) 260 warning("initial setsid() failed: %m"); 261 262 /* 263 * Establish an initial user so that programs running 264 * single user do not freak out and die (like passwd). 265 */ 266 if (setlogin("root") < 0) 267 warning("setlogin() failed: %m"); 268 269 /* 270 * This code assumes that we always get arguments through flags, 271 * never through bits set in some random machine register. 272 */ 273 while ((c = getopt(argc, argv, "dsfr")) != -1) 274 switch (c) { 275 case 'd': 276 devfs = 1; 277 break; 278 case 's': 279 initial_transition = single_user; 280 break; 281 case 'f': 282 runcom_mode = FASTBOOT; 283 break; 284 case 'r': 285 initial_transition = reroot_phase_two; 286 break; 287 default: 288 warning("unrecognized flag '-%c'", c); 289 break; 290 } 291 292 if (optind != argc) 293 warning("ignoring excess arguments"); 294 295 /* 296 * We catch or block signals rather than ignore them, 297 * so that they get reset on exec. 298 */ 299 handle(badsys, SIGSYS, 0); 300 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGXCPU, 301 SIGXFSZ, 0); 302 handle(transition_handler, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 303 SIGUSR1, SIGUSR2, 0); 304 handle(alrm_handler, SIGALRM, 0); 305 sigfillset(&mask); 306 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 307 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGEMT, SIGTERM, SIGTSTP, 308 SIGALRM, SIGUSR1, SIGUSR2, 0); 309 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 310 sigemptyset(&sa.sa_mask); 311 sa.sa_flags = 0; 312 sa.sa_handler = SIG_IGN; 313 sigaction(SIGTTIN, &sa, (struct sigaction *)0); 314 sigaction(SIGTTOU, &sa, (struct sigaction *)0); 315 316 /* 317 * Paranoia. 318 */ 319 close(0); 320 close(1); 321 close(2); 322 323 if (kenv(KENV_GET, "init_script", kenv_value, sizeof(kenv_value)) > 0) { 324 state_func_t next_transition; 325 326 if ((next_transition = run_script(kenv_value)) != 0) 327 initial_transition = (state_t) next_transition; 328 } 329 330 if (kenv(KENV_GET, "init_chroot", kenv_value, sizeof(kenv_value)) > 0) { 331 if (chdir(kenv_value) != 0 || chroot(".") != 0) 332 warning("Can't chroot to %s: %m", kenv_value); 333 } 334 335 /* 336 * Additional check if devfs needs to be mounted: 337 * If "/" and "/dev" have the same device number, 338 * then it hasn't been mounted yet. 339 */ 340 if (!devfs) { 341 struct stat stst; 342 dev_t root_devno; 343 344 stat("/", &stst); 345 root_devno = stst.st_dev; 346 if (stat("/dev", &stst) != 0) 347 warning("Can't stat /dev: %m"); 348 else if (stst.st_dev == root_devno) 349 devfs++; 350 } 351 352 if (devfs) { 353 struct iovec iov[4]; 354 char *s; 355 int i; 356 357 char _fstype[] = "fstype"; 358 char _devfs[] = "devfs"; 359 char _fspath[] = "fspath"; 360 char _path_dev[]= _PATH_DEV; 361 362 iov[0].iov_base = _fstype; 363 iov[0].iov_len = sizeof(_fstype); 364 iov[1].iov_base = _devfs; 365 iov[1].iov_len = sizeof(_devfs); 366 iov[2].iov_base = _fspath; 367 iov[2].iov_len = sizeof(_fspath); 368 /* 369 * Try to avoid the trailing slash in _PATH_DEV. 370 * Be *very* defensive. 371 */ 372 s = strdup(_PATH_DEV); 373 if (s != NULL) { 374 i = strlen(s); 375 if (i > 0 && s[i - 1] == '/') 376 s[i - 1] = '\0'; 377 iov[3].iov_base = s; 378 iov[3].iov_len = strlen(s) + 1; 379 } else { 380 iov[3].iov_base = _path_dev; 381 iov[3].iov_len = sizeof(_path_dev); 382 } 383 nmount(iov, 4, 0); 384 if (s != NULL) 385 free(s); 386 } 387 388 if (initial_transition != reroot_phase_two) { 389 /* 390 * Unmount reroot leftovers. This runs after init(8) 391 * gets reexecuted after reroot_phase_two() is done. 392 */ 393 error = unmount(_PATH_REROOT, MNT_FORCE); 394 if (error != 0 && errno != EINVAL) 395 warning("Cannot unmount %s: %m", _PATH_REROOT); 396 } 397 398 /* 399 * Start the state machine. 400 */ 401 transition(initial_transition); 402 403 /* 404 * Should never reach here. 405 */ 406 return 1; 407} 408 409/* 410 * Associate a function with a signal handler. 411 */ 412static void 413handle(sig_t handler, ...) 414{ 415 int sig; 416 struct sigaction sa; 417 sigset_t mask_everything; 418 va_list ap; 419 va_start(ap, handler); 420 421 sa.sa_handler = handler; 422 sigfillset(&mask_everything); 423 424 while ((sig = va_arg(ap, int)) != 0) { 425 sa.sa_mask = mask_everything; 426 /* XXX SA_RESTART? */ 427 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 428 sigaction(sig, &sa, (struct sigaction *) 0); 429 } 430 va_end(ap); 431} 432 433/* 434 * Delete a set of signals from a mask. 435 */ 436static void 437delset(sigset_t *maskp, ...) 438{ 439 int sig; 440 va_list ap; 441 va_start(ap, maskp); 442 443 while ((sig = va_arg(ap, int)) != 0) 444 sigdelset(maskp, sig); 445 va_end(ap); 446} 447 448/* 449 * Log a message and sleep for a while (to give someone an opportunity 450 * to read it and to save log or hardcopy output if the problem is chronic). 451 * NB: should send a message to the session logger to avoid blocking. 452 */ 453static void 454stall(const char *message, ...) 455{ 456 va_list ap; 457 va_start(ap, message); 458 459 vsyslog(LOG_ALERT, message, ap); 460 va_end(ap); 461 sleep(STALL_TIMEOUT); 462} 463 464/* 465 * Like stall(), but doesn't sleep. 466 * If cpp had variadic macros, the two functions could be #defines for another. 467 * NB: should send a message to the session logger to avoid blocking. 468 */ 469static void 470warning(const char *message, ...) 471{ 472 va_list ap; 473 va_start(ap, message); 474 475 vsyslog(LOG_ALERT, message, ap); 476 va_end(ap); 477} 478 479/* 480 * Log an emergency message. 481 * NB: should send a message to the session logger to avoid blocking. 482 */ 483static void 484emergency(const char *message, ...) 485{ 486 va_list ap; 487 va_start(ap, message); 488 489 vsyslog(LOG_EMERG, message, ap); 490 va_end(ap); 491} 492 493/* 494 * Catch a SIGSYS signal. 495 * 496 * These may arise if a system does not support sysctl. 497 * We tolerate up to 25 of these, then throw in the towel. 498 */ 499static void 500badsys(int sig) 501{ 502 static int badcount = 0; 503 504 if (badcount++ < 25) 505 return; 506 disaster(sig); 507} 508 509/* 510 * Catch an unexpected signal. 511 */ 512static void 513disaster(int sig) 514{ 515 516 emergency("fatal signal: %s", 517 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal"); 518 519 sleep(STALL_TIMEOUT); 520 _exit(sig); /* reboot */ 521} 522 523/* 524 * Get the security level of the kernel. 525 */ 526static int 527getsecuritylevel(void) 528{ 529#ifdef KERN_SECURELVL 530 int name[2], curlevel; 531 size_t len; 532 533 name[0] = CTL_KERN; 534 name[1] = KERN_SECURELVL; 535 len = sizeof curlevel; 536 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 537 emergency("cannot get kernel security level: %s", 538 strerror(errno)); 539 return (-1); 540 } 541 return (curlevel); 542#else 543 return (-1); 544#endif 545} 546 547/* 548 * Set the security level of the kernel. 549 */ 550static void 551setsecuritylevel(int newlevel) 552{ 553#ifdef KERN_SECURELVL 554 int name[2], curlevel; 555 556 curlevel = getsecuritylevel(); 557 if (newlevel == curlevel) 558 return; 559 name[0] = CTL_KERN; 560 name[1] = KERN_SECURELVL; 561 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 562 emergency( 563 "cannot change kernel security level from %d to %d: %s", 564 curlevel, newlevel, strerror(errno)); 565 return; 566 } 567#ifdef SECURE 568 warning("kernel security level changed from %d to %d", 569 curlevel, newlevel); 570#endif 571#endif 572} 573 574/* 575 * Change states in the finite state machine. 576 * The initial state is passed as an argument. 577 */ 578static void 579transition(state_t s) 580{ 581 582 current_state = s; 583 for (;;) 584 current_state = (state_t) (*current_state)(); 585} 586 587/* 588 * Start a session and allocate a controlling terminal. 589 * Only called by children of init after forking. 590 */ 591static void 592open_console(void) 593{ 594 int fd; 595 596 /* 597 * Try to open /dev/console. Open the device with O_NONBLOCK to 598 * prevent potential blocking on a carrier. 599 */ 600 revoke(_PATH_CONSOLE); 601 if ((fd = open(_PATH_CONSOLE, O_RDWR | O_NONBLOCK)) != -1) { 602 (void)fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK); 603 if (login_tty(fd) == 0) 604 return; 605 close(fd); 606 } 607 608 /* No luck. Log output to file if possible. */ 609 if ((fd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 610 stall("cannot open null device."); 611 _exit(1); 612 } 613 if (fd != STDIN_FILENO) { 614 dup2(fd, STDIN_FILENO); 615 close(fd); 616 } 617 fd = open(_PATH_INITLOG, O_WRONLY | O_APPEND | O_CREAT, 0644); 618 if (fd == -1) 619 dup2(STDIN_FILENO, STDOUT_FILENO); 620 else if (fd != STDOUT_FILENO) { 621 dup2(fd, STDOUT_FILENO); 622 close(fd); 623 } 624 dup2(STDOUT_FILENO, STDERR_FILENO); 625} 626 627static const char * 628get_shell(void) 629{ 630 static char kenv_value[PATH_MAX]; 631 632 if (kenv(KENV_GET, "init_shell", kenv_value, sizeof(kenv_value)) > 0) 633 return kenv_value; 634 else 635 return _PATH_BSHELL; 636} 637 638static void 639write_stderr(const char *message) 640{ 641 642 write(STDERR_FILENO, message, strlen(message)); 643} 644 645static int 646read_file(const char *path, void **bufp, size_t *bufsizep) 647{ 648 struct stat sb; 649 size_t bufsize; 650 void *buf; 651 ssize_t nbytes; 652 int error, fd; 653 654 fd = open(path, O_RDONLY); 655 if (fd < 0) { 656 emergency("%s: %s", path, strerror(errno)); 657 return (-1); 658 } 659 660 error = fstat(fd, &sb); 661 if (error != 0) { 662 emergency("fstat: %s", strerror(errno)); 663 return (error); 664 } 665 666 bufsize = sb.st_size; 667 buf = malloc(bufsize); 668 if (buf == NULL) { 669 emergency("malloc: %s", strerror(errno)); 670 return (error); 671 } 672 673 nbytes = read(fd, buf, bufsize); 674 if (nbytes != (ssize_t)bufsize) { 675 emergency("read: %s", strerror(errno)); 676 free(buf); 677 return (error); 678 } 679 680 error = close(fd); 681 if (error != 0) { 682 emergency("close: %s", strerror(errno)); 683 free(buf); 684 return (error); 685 } 686 687 *bufp = buf; 688 *bufsizep = bufsize; 689 690 return (0); 691} 692 693static int 694create_file(const char *path, void *buf, size_t bufsize) 695{ 696 ssize_t nbytes; 697 int error, fd; 698 699 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 700 if (fd < 0) { 701 emergency("%s: %s", path, strerror(errno)); 702 return (-1); 703 } 704 705 nbytes = write(fd, buf, bufsize); 706 if (nbytes != (ssize_t)bufsize) { 707 emergency("write: %s", strerror(errno)); 708 return (-1); 709 } 710 711 error = close(fd); 712 if (error != 0) { 713 emergency("close: %s", strerror(errno)); 714 free(buf); 715 return (-1); 716 } 717 718 return (0); 719} 720 721static int 722mount_tmpfs(const char *fspath) 723{ 724 struct iovec *iov; 725 char errmsg[255]; 726 int error, iovlen; 727 728 iov = NULL; 729 iovlen = 0; 730 memset(errmsg, 0, sizeof(errmsg)); 731 build_iovec(&iov, &iovlen, "fstype", 732 __DECONST(void *, "tmpfs"), (size_t)-1); 733 build_iovec(&iov, &iovlen, "fspath", 734 __DECONST(void *, fspath), (size_t)-1); 735 build_iovec(&iov, &iovlen, "errmsg", 736 errmsg, sizeof(errmsg)); 737 738 error = nmount(iov, iovlen, 0); 739 if (error != 0) { 740 if (*errmsg != '\0') { 741 emergency("cannot mount tmpfs on %s: %s: %s", 742 fspath, errmsg, strerror(errno)); 743 } else { 744 emergency("cannot mount tmpfs on %s: %s", 745 fspath, strerror(errno)); 746 } 747 return (error); 748 } 749 return (0); 750} 751 752static state_func_t 753reroot(void) 754{ 755 void *buf; 756 char init_path[PATH_MAX]; 757 size_t bufsize, init_path_len; 758 int error, name[4]; 759 760 name[0] = CTL_KERN; 761 name[1] = KERN_PROC; 762 name[2] = KERN_PROC_PATHNAME; 763 name[3] = -1; 764 init_path_len = sizeof(init_path); 765 error = sysctl(name, 4, init_path, &init_path_len, NULL, 0); 766 if (error != 0) { 767 emergency("failed to get kern.proc.pathname: %s", 768 strerror(errno)); 769 goto out; 770 } 771 772 revoke_ttys(); 773 runshutdown(); 774 775 /* 776 * Make sure nobody can interfere with our scheme. 777 */ 778 error = kill(-1, SIGKILL); 779 if (error != 0) { 780 emergency("kill(2) failed: %s", strerror(errno)); 781 goto out; 782 } 783 784 /* 785 * Pacify GCC. 786 */ 787 buf = NULL; 788 bufsize = 0; 789 790 /* 791 * Copy the init binary into tmpfs, so that we can unmount 792 * the old rootfs without committing suicide. 793 */ 794 error = read_file(init_path, &buf, &bufsize); 795 if (error != 0) 796 goto out; 797 error = mount_tmpfs(_PATH_REROOT); 798 if (error != 0) 799 goto out; 800 error = create_file(_PATH_REROOT_INIT, buf, bufsize); 801 if (error != 0) 802 goto out; 803 804 /* 805 * Execute the temporary init. 806 */ 807 execl(_PATH_REROOT_INIT, _PATH_REROOT_INIT, "-r", NULL); 808 emergency("cannot exec %s: %s", _PATH_REROOT_INIT, strerror(errno)); 809 810out: 811 emergency("reroot failed; going to single user mode"); 812 return (state_func_t) single_user; 813} 814 815static state_func_t 816reroot_phase_two(void) 817{ 818 char init_path[PATH_MAX], *path, *path_component; 819 size_t init_path_len; 820 int nbytes, error; 821 822 /* 823 * Ask the kernel to mount the new rootfs. 824 */ 825 error = reboot(RB_REROOT); 826 if (error != 0) { 827 emergency("RB_REBOOT failed: %s", strerror(errno)); 828 goto out; 829 } 830 831 /* 832 * Figure out where the destination init(8) binary is. Note that 833 * the path could be different than what we've started with. Use 834 * the value from kenv, if set, or the one from sysctl otherwise. 835 * The latter defaults to a hardcoded value, but can be overridden 836 * by a build time option. 837 */ 838 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 839 if (nbytes <= 0) { 840 init_path_len = sizeof(init_path); 841 error = sysctlbyname("kern.init_path", 842 init_path, &init_path_len, NULL, 0); 843 if (error != 0) { 844 emergency("failed to retrieve kern.init_path: %s", 845 strerror(errno)); 846 goto out; 847 } 848 } 849 850 /* 851 * Repeat the init search logic from sys/kern/init_path.c 852 */ 853 path_component = init_path; 854 while ((path = strsep(&path_component, ":")) != NULL) { 855 /* 856 * Execute init(8) from the new rootfs. 857 */ 858 execl(path, path, NULL); 859 } 860 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 861 862out: 863 emergency("reroot failed; going to single user mode"); 864 return (state_func_t) single_user; 865} 866 867/* 868 * Bring the system up single user. 869 */ 870static state_func_t 871single_user(void) 872{ 873 pid_t pid, wpid; 874 int status; 875 sigset_t mask; 876 const char *shell; 877 char *argv[2]; 878#ifdef SECURE 879 struct ttyent *typ; 880 struct passwd *pp; 881 static const char banner[] = 882 "Enter root password, or ^D to go multi-user\n"; 883 char *clear, *password; 884#endif 885#ifdef DEBUGSHELL 886 char altshell[128]; 887#endif 888 889 if (Reboot) { 890 /* Instead of going single user, let's reboot the machine */ 891 sync(); 892 reboot(howto); 893 _exit(0); 894 } 895 896 shell = get_shell(); 897 898 if ((pid = fork()) == 0) { 899 /* 900 * Start the single user session. 901 */ 902 open_console(); 903 904#ifdef SECURE 905 /* 906 * Check the root password. 907 * We don't care if the console is 'on' by default; 908 * it's the only tty that can be 'off' and 'secure'. 909 */ 910 typ = getttynam("console"); 911 pp = getpwnam("root"); 912 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 913 pp && *pp->pw_passwd) { 914 write_stderr(banner); 915 for (;;) { 916 clear = getpass("Password:"); 917 if (clear == 0 || *clear == '\0') 918 _exit(0); 919 password = crypt(clear, pp->pw_passwd); 920 bzero(clear, _PASSWORD_LEN); 921 if (password == NULL || 922 strcmp(password, pp->pw_passwd) == 0) 923 break; 924 warning("single-user login failed\n"); 925 } 926 } 927 endttyent(); 928 endpwent(); 929#endif /* SECURE */ 930 931#ifdef DEBUGSHELL 932 { 933 char *cp = altshell; 934 int num; 935 936#define SHREQUEST "Enter full pathname of shell or RETURN for " 937 write_stderr(SHREQUEST); 938 write_stderr(shell); 939 write_stderr(": "); 940 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 941 num != 0 && *cp != '\n' && cp < &altshell[127]) 942 cp++; 943 *cp = '\0'; 944 if (altshell[0] != '\0') 945 shell = altshell; 946 } 947#endif /* DEBUGSHELL */ 948 949 /* 950 * Unblock signals. 951 * We catch all the interesting ones, 952 * and those are reset to SIG_DFL on exec. 953 */ 954 sigemptyset(&mask); 955 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 956 957 /* 958 * Fire off a shell. 959 * If the default one doesn't work, try the Bourne shell. 960 */ 961 962 char name[] = "-sh"; 963 964 argv[0] = name; 965 argv[1] = 0; 966 execv(shell, argv); 967 emergency("can't exec %s for single user: %m", shell); 968 execv(_PATH_BSHELL, argv); 969 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 970 sleep(STALL_TIMEOUT); 971 _exit(1); 972 } 973 974 if (pid == -1) { 975 /* 976 * We are seriously hosed. Do our best. 977 */ 978 emergency("can't fork single-user shell, trying again"); 979 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 980 continue; 981 return (state_func_t) single_user; 982 } 983 984 requested_transition = 0; 985 do { 986 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 987 collect_child(wpid); 988 if (wpid == -1) { 989 if (errno == EINTR) 990 continue; 991 warning("wait for single-user shell failed: %m; restarting"); 992 return (state_func_t) single_user; 993 } 994 if (wpid == pid && WIFSTOPPED(status)) { 995 warning("init: shell stopped, restarting\n"); 996 kill(pid, SIGCONT); 997 wpid = -1; 998 } 999 } while (wpid != pid && !requested_transition); 1000 1001 if (requested_transition) 1002 return (state_func_t) requested_transition; 1003 1004 if (!WIFEXITED(status)) { 1005 if (WTERMSIG(status) == SIGKILL) { 1006 /* 1007 * reboot(8) killed shell? 1008 */ 1009 warning("single user shell terminated."); 1010 sleep(STALL_TIMEOUT); 1011 _exit(0); 1012 } else { 1013 warning("single user shell terminated, restarting"); 1014 return (state_func_t) single_user; 1015 } 1016 } 1017 1018 runcom_mode = FASTBOOT; 1019 return (state_func_t) runcom; 1020} 1021 1022/* 1023 * Run the system startup script. 1024 */ 1025static state_func_t 1026runcom(void) 1027{ 1028 state_func_t next_transition; 1029 1030 if ((next_transition = run_script(_PATH_RUNCOM)) != 0) 1031 return next_transition; 1032 1033 runcom_mode = AUTOBOOT; /* the default */ 1034 return (state_func_t) read_ttys; 1035} 1036 1037/* 1038 * Run a shell script. 1039 * Returns 0 on success, otherwise the next transition to enter: 1040 * - single_user if fork/execv/waitpid failed, or if the script 1041 * terminated with a signal or exit code != 0. 1042 * - death_single if a SIGTERM was delivered to init(8). 1043 */ 1044static state_func_t 1045run_script(const char *script) 1046{ 1047 pid_t pid, wpid; 1048 int status; 1049 char *argv[4]; 1050 const char *shell; 1051 struct sigaction sa; 1052 1053 shell = get_shell(); 1054 1055 if ((pid = fork()) == 0) { 1056 sigemptyset(&sa.sa_mask); 1057 sa.sa_flags = 0; 1058 sa.sa_handler = SIG_IGN; 1059 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1060 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1061 1062 open_console(); 1063 1064 char _sh[] = "sh"; 1065 char _autoboot[] = "autoboot"; 1066 1067 argv[0] = _sh; 1068 argv[1] = __DECONST(char *, script); 1069 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1070 argv[3] = 0; 1071 1072 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1073 1074#ifdef LOGIN_CAP 1075 setprocresources(RESOURCE_RC); 1076#endif 1077 execv(shell, argv); 1078 stall("can't exec %s for %s: %m", shell, script); 1079 _exit(1); /* force single user mode */ 1080 } 1081 1082 if (pid == -1) { 1083 emergency("can't fork for %s on %s: %m", shell, script); 1084 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1085 continue; 1086 sleep(STALL_TIMEOUT); 1087 return (state_func_t) single_user; 1088 } 1089 1090 /* 1091 * Copied from single_user(). This is a bit paranoid. 1092 */ 1093 requested_transition = 0; 1094 do { 1095 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1096 collect_child(wpid); 1097 if (wpid == -1) { 1098 if (requested_transition == death_single || 1099 requested_transition == reroot) 1100 return (state_func_t) requested_transition; 1101 if (errno == EINTR) 1102 continue; 1103 warning("wait for %s on %s failed: %m; going to " 1104 "single user mode", shell, script); 1105 return (state_func_t) single_user; 1106 } 1107 if (wpid == pid && WIFSTOPPED(status)) { 1108 warning("init: %s on %s stopped, restarting\n", 1109 shell, script); 1110 kill(pid, SIGCONT); 1111 wpid = -1; 1112 } 1113 } while (wpid != pid); 1114 1115 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1116 requested_transition == catatonia) { 1117 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1118 sigset_t s; 1119 1120 sigfillset(&s); 1121 for (;;) 1122 sigsuspend(&s); 1123 } 1124 1125 if (!WIFEXITED(status)) { 1126 warning("%s on %s terminated abnormally, going to single " 1127 "user mode", shell, script); 1128 return (state_func_t) single_user; 1129 } 1130 1131 if (WEXITSTATUS(status)) 1132 return (state_func_t) single_user; 1133 1134 return (state_func_t) 0; 1135} 1136 1137/* 1138 * Open the session database. 1139 * 1140 * NB: We could pass in the size here; is it necessary? 1141 */ 1142static int 1143start_session_db(void) 1144{ 1145 if (session_db && (*session_db->close)(session_db)) 1146 emergency("session database close: %s", strerror(errno)); 1147 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 1148 emergency("session database open: %s", strerror(errno)); 1149 return (1); 1150 } 1151 return (0); 1152 1153} 1154 1155/* 1156 * Add a new login session. 1157 */ 1158static void 1159add_session(session_t *sp) 1160{ 1161 DBT key; 1162 DBT data; 1163 1164 key.data = &sp->se_process; 1165 key.size = sizeof sp->se_process; 1166 data.data = &sp; 1167 data.size = sizeof sp; 1168 1169 if ((*session_db->put)(session_db, &key, &data, 0)) 1170 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1171} 1172 1173/* 1174 * Delete an old login session. 1175 */ 1176static void 1177del_session(session_t *sp) 1178{ 1179 DBT key; 1180 1181 key.data = &sp->se_process; 1182 key.size = sizeof sp->se_process; 1183 1184 if ((*session_db->del)(session_db, &key, 0)) 1185 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1186} 1187 1188/* 1189 * Look up a login session by pid. 1190 */ 1191static session_t * 1192find_session(pid_t pid) 1193{ 1194 DBT key; 1195 DBT data; 1196 session_t *ret; 1197 1198 key.data = &pid; 1199 key.size = sizeof pid; 1200 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1201 return 0; 1202 bcopy(data.data, (char *)&ret, sizeof(ret)); 1203 return ret; 1204} 1205 1206/* 1207 * Construct an argument vector from a command line. 1208 */ 1209static char ** 1210construct_argv(char *command) 1211{ 1212 int argc = 0; 1213 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1214 * sizeof (char *)); 1215 1216 if ((argv[argc++] = strk(command)) == 0) { 1217 free(argv); 1218 return (NULL); 1219 } 1220 while ((argv[argc++] = strk((char *) 0)) != NULL) 1221 continue; 1222 return argv; 1223} 1224 1225/* 1226 * Deallocate a session descriptor. 1227 */ 1228static void 1229free_session(session_t *sp) 1230{ 1231 free(sp->se_device); 1232 if (sp->se_getty) { 1233 free(sp->se_getty); 1234 free(sp->se_getty_argv_space); 1235 free(sp->se_getty_argv); 1236 } 1237 if (sp->se_window) { 1238 free(sp->se_window); 1239 free(sp->se_window_argv_space); 1240 free(sp->se_window_argv); 1241 } 1242 if (sp->se_type) 1243 free(sp->se_type); 1244 free(sp); 1245} 1246 1247/* 1248 * Allocate a new session descriptor. 1249 * Mark it SE_PRESENT. 1250 */ 1251static session_t * 1252new_session(session_t *sprev, int session_index, struct ttyent *typ) 1253{ 1254 session_t *sp; 1255 int fd; 1256 1257 if ((typ->ty_status & TTY_ON) == 0 || 1258 typ->ty_name == 0 || 1259 typ->ty_getty == 0) 1260 return 0; 1261 1262 sp = (session_t *) calloc(1, sizeof (session_t)); 1263 1264 sp->se_index = session_index; 1265 sp->se_flags |= SE_PRESENT; 1266 1267 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 1268 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 1269 1270 /* 1271 * Attempt to open the device, if we get "device not configured" 1272 * then don't add the device to the session list. 1273 */ 1274 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) { 1275 if (errno == ENXIO) { 1276 free_session(sp); 1277 return (0); 1278 } 1279 } else 1280 close(fd); 1281 1282 if (setupargv(sp, typ) == 0) { 1283 free_session(sp); 1284 return (0); 1285 } 1286 1287 sp->se_next = 0; 1288 if (sprev == 0) { 1289 sessions = sp; 1290 sp->se_prev = 0; 1291 } else { 1292 sprev->se_next = sp; 1293 sp->se_prev = sprev; 1294 } 1295 1296 return sp; 1297} 1298 1299/* 1300 * Calculate getty and if useful window argv vectors. 1301 */ 1302static int 1303setupargv(session_t *sp, struct ttyent *typ) 1304{ 1305 1306 if (sp->se_getty) { 1307 free(sp->se_getty); 1308 free(sp->se_getty_argv_space); 1309 free(sp->se_getty_argv); 1310 } 1311 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 1312 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 1313 sp->se_getty_argv_space = strdup(sp->se_getty); 1314 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1315 if (sp->se_getty_argv == 0) { 1316 warning("can't parse getty for port %s", sp->se_device); 1317 free(sp->se_getty); 1318 free(sp->se_getty_argv_space); 1319 sp->se_getty = sp->se_getty_argv_space = 0; 1320 return (0); 1321 } 1322 if (sp->se_window) { 1323 free(sp->se_window); 1324 free(sp->se_window_argv_space); 1325 free(sp->se_window_argv); 1326 } 1327 sp->se_window = sp->se_window_argv_space = 0; 1328 sp->se_window_argv = 0; 1329 if (typ->ty_window) { 1330 sp->se_window = strdup(typ->ty_window); 1331 sp->se_window_argv_space = strdup(sp->se_window); 1332 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1333 if (sp->se_window_argv == 0) { 1334 warning("can't parse window for port %s", 1335 sp->se_device); 1336 free(sp->se_window_argv_space); 1337 free(sp->se_window); 1338 sp->se_window = sp->se_window_argv_space = 0; 1339 return (0); 1340 } 1341 } 1342 if (sp->se_type) 1343 free(sp->se_type); 1344 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1345 return (1); 1346} 1347 1348/* 1349 * Walk the list of ttys and create sessions for each active line. 1350 */ 1351static state_func_t 1352read_ttys(void) 1353{ 1354 int session_index = 0; 1355 session_t *sp, *snext; 1356 struct ttyent *typ; 1357 1358 /* 1359 * Destroy any previous session state. 1360 * There shouldn't be any, but just in case... 1361 */ 1362 for (sp = sessions; sp; sp = snext) { 1363 snext = sp->se_next; 1364 free_session(sp); 1365 } 1366 sessions = 0; 1367 if (start_session_db()) 1368 return (state_func_t) single_user; 1369 1370 /* 1371 * Allocate a session entry for each active port. 1372 * Note that sp starts at 0. 1373 */ 1374 while ((typ = getttyent()) != NULL) 1375 if ((snext = new_session(sp, ++session_index, typ)) != NULL) 1376 sp = snext; 1377 1378 endttyent(); 1379 1380 return (state_func_t) multi_user; 1381} 1382 1383/* 1384 * Start a window system running. 1385 */ 1386static void 1387start_window_system(session_t *sp) 1388{ 1389 pid_t pid; 1390 sigset_t mask; 1391 char term[64], *env[2]; 1392 int status; 1393 1394 if ((pid = fork()) == -1) { 1395 emergency("can't fork for window system on port %s: %m", 1396 sp->se_device); 1397 /* hope that getty fails and we can try again */ 1398 return; 1399 } 1400 if (pid) { 1401 waitpid(-1, &status, 0); 1402 return; 1403 } 1404 1405 /* reparent window process to the init to not make a zombie on exit */ 1406 if ((pid = fork()) == -1) { 1407 emergency("can't fork for window system on port %s: %m", 1408 sp->se_device); 1409 _exit(1); 1410 } 1411 if (pid) 1412 _exit(0); 1413 1414 sigemptyset(&mask); 1415 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1416 1417 if (setsid() < 0) 1418 emergency("setsid failed (window) %m"); 1419 1420#ifdef LOGIN_CAP 1421 setprocresources(RESOURCE_WINDOW); 1422#endif 1423 if (sp->se_type) { 1424 /* Don't use malloc after fork */ 1425 strcpy(term, "TERM="); 1426 strncat(term, sp->se_type, sizeof(term) - 6); 1427 env[0] = term; 1428 env[1] = 0; 1429 } 1430 else 1431 env[0] = 0; 1432 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1433 stall("can't exec window system '%s' for port %s: %m", 1434 sp->se_window_argv[0], sp->se_device); 1435 _exit(1); 1436} 1437 1438/* 1439 * Start a login session running. 1440 */ 1441static pid_t 1442start_getty(session_t *sp) 1443{ 1444 pid_t pid; 1445 sigset_t mask; 1446 time_t current_time = time((time_t *) 0); 1447 int too_quick = 0; 1448 char term[64], *env[2]; 1449 1450 if (current_time >= sp->se_started && 1451 current_time - sp->se_started < GETTY_SPACING) { 1452 if (++sp->se_nspace > GETTY_NSPACE) { 1453 sp->se_nspace = 0; 1454 too_quick = 1; 1455 } 1456 } else 1457 sp->se_nspace = 0; 1458 1459 /* 1460 * fork(), not vfork() -- we can't afford to block. 1461 */ 1462 if ((pid = fork()) == -1) { 1463 emergency("can't fork for getty on port %s: %m", sp->se_device); 1464 return -1; 1465 } 1466 1467 if (pid) 1468 return pid; 1469 1470 if (too_quick) { 1471 warning("getty repeating too quickly on port %s, sleeping %d secs", 1472 sp->se_device, GETTY_SLEEP); 1473 sleep((unsigned) GETTY_SLEEP); 1474 } 1475 1476 if (sp->se_window) { 1477 start_window_system(sp); 1478 sleep(WINDOW_WAIT); 1479 } 1480 1481 sigemptyset(&mask); 1482 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1483 1484#ifdef LOGIN_CAP 1485 setprocresources(RESOURCE_GETTY); 1486#endif 1487 if (sp->se_type) { 1488 /* Don't use malloc after fork */ 1489 strcpy(term, "TERM="); 1490 strncat(term, sp->se_type, sizeof(term) - 6); 1491 env[0] = term; 1492 env[1] = 0; 1493 } else 1494 env[0] = 0; 1495 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1496 stall("can't exec getty '%s' for port %s: %m", 1497 sp->se_getty_argv[0], sp->se_device); 1498 _exit(1); 1499} 1500 1501/* 1502 * Collect exit status for a child. 1503 * If an exiting login, start a new login running. 1504 */ 1505static void 1506collect_child(pid_t pid) 1507{ 1508 session_t *sp, *sprev, *snext; 1509 1510 if (! sessions) 1511 return; 1512 1513 if (! (sp = find_session(pid))) 1514 return; 1515 1516 del_session(sp); 1517 sp->se_process = 0; 1518 1519 if (sp->se_flags & SE_SHUTDOWN) { 1520 if ((sprev = sp->se_prev) != NULL) 1521 sprev->se_next = sp->se_next; 1522 else 1523 sessions = sp->se_next; 1524 if ((snext = sp->se_next) != NULL) 1525 snext->se_prev = sp->se_prev; 1526 free_session(sp); 1527 return; 1528 } 1529 1530 if ((pid = start_getty(sp)) == -1) { 1531 /* serious trouble */ 1532 requested_transition = clean_ttys; 1533 return; 1534 } 1535 1536 sp->se_process = pid; 1537 sp->se_started = time((time_t *) 0); 1538 add_session(sp); 1539} 1540 1541/* 1542 * Catch a signal and request a state transition. 1543 */ 1544static void 1545transition_handler(int sig) 1546{ 1547 1548 switch (sig) { 1549 case SIGHUP: 1550 if (current_state == read_ttys || current_state == multi_user || 1551 current_state == clean_ttys || current_state == catatonia) 1552 requested_transition = clean_ttys; 1553 break; 1554 case SIGUSR2: 1555 howto = RB_POWEROFF; 1556 case SIGUSR1: 1557 howto |= RB_HALT; 1558 case SIGINT: 1559 Reboot = TRUE; 1560 case SIGTERM: 1561 if (current_state == read_ttys || current_state == multi_user || 1562 current_state == clean_ttys || current_state == catatonia) 1563 requested_transition = death; 1564 else 1565 requested_transition = death_single; 1566 break; 1567 case SIGTSTP: 1568 if (current_state == runcom || current_state == read_ttys || 1569 current_state == clean_ttys || 1570 current_state == multi_user || current_state == catatonia) 1571 requested_transition = catatonia; 1572 break; 1573 case SIGEMT: 1574 requested_transition = reroot; 1575 break; 1576 default: 1577 requested_transition = 0; 1578 break; 1579 } 1580} 1581 1582/* 1583 * Take the system multiuser. 1584 */ 1585static state_func_t 1586multi_user(void) 1587{ 1588 pid_t pid; 1589 session_t *sp; 1590 1591 requested_transition = 0; 1592 1593 /* 1594 * If the administrator has not set the security level to -1 1595 * to indicate that the kernel should not run multiuser in secure 1596 * mode, and the run script has not set a higher level of security 1597 * than level 1, then put the kernel into secure mode. 1598 */ 1599 if (getsecuritylevel() == 0) 1600 setsecuritylevel(1); 1601 1602 for (sp = sessions; sp; sp = sp->se_next) { 1603 if (sp->se_process) 1604 continue; 1605 if ((pid = start_getty(sp)) == -1) { 1606 /* serious trouble */ 1607 requested_transition = clean_ttys; 1608 break; 1609 } 1610 sp->se_process = pid; 1611 sp->se_started = time((time_t *) 0); 1612 add_session(sp); 1613 } 1614 1615 while (!requested_transition) 1616 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1617 collect_child(pid); 1618 1619 return (state_func_t) requested_transition; 1620} 1621 1622/* 1623 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1624 */ 1625static state_func_t 1626clean_ttys(void) 1627{ 1628 session_t *sp, *sprev; 1629 struct ttyent *typ; 1630 int session_index = 0; 1631 int devlen; 1632 char *old_getty, *old_window, *old_type; 1633 1634 /* 1635 * mark all sessions for death, (!SE_PRESENT) 1636 * as we find or create new ones they'll be marked as keepers, 1637 * we'll later nuke all the ones not found in /etc/ttys 1638 */ 1639 for (sp = sessions; sp != NULL; sp = sp->se_next) 1640 sp->se_flags &= ~SE_PRESENT; 1641 1642 devlen = sizeof(_PATH_DEV) - 1; 1643 while ((typ = getttyent()) != NULL) { 1644 ++session_index; 1645 1646 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1647 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1648 break; 1649 1650 if (sp) { 1651 /* we want this one to live */ 1652 sp->se_flags |= SE_PRESENT; 1653 if (sp->se_index != session_index) { 1654 warning("port %s changed utmp index from %d to %d", 1655 sp->se_device, sp->se_index, 1656 session_index); 1657 sp->se_index = session_index; 1658 } 1659 if ((typ->ty_status & TTY_ON) == 0 || 1660 typ->ty_getty == 0) { 1661 sp->se_flags |= SE_SHUTDOWN; 1662 kill(sp->se_process, SIGHUP); 1663 continue; 1664 } 1665 sp->se_flags &= ~SE_SHUTDOWN; 1666 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1667 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1668 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1669 if (setupargv(sp, typ) == 0) { 1670 warning("can't parse getty for port %s", 1671 sp->se_device); 1672 sp->se_flags |= SE_SHUTDOWN; 1673 kill(sp->se_process, SIGHUP); 1674 } 1675 else if ( !old_getty 1676 || (!old_type && sp->se_type) 1677 || (old_type && !sp->se_type) 1678 || (!old_window && sp->se_window) 1679 || (old_window && !sp->se_window) 1680 || (strcmp(old_getty, sp->se_getty) != 0) 1681 || (old_window && strcmp(old_window, sp->se_window) != 0) 1682 || (old_type && strcmp(old_type, sp->se_type) != 0) 1683 ) { 1684 /* Don't set SE_SHUTDOWN here */ 1685 sp->se_nspace = 0; 1686 sp->se_started = 0; 1687 kill(sp->se_process, SIGHUP); 1688 } 1689 if (old_getty) 1690 free(old_getty); 1691 if (old_window) 1692 free(old_window); 1693 if (old_type) 1694 free(old_type); 1695 continue; 1696 } 1697 1698 new_session(sprev, session_index, typ); 1699 } 1700 1701 endttyent(); 1702 1703 /* 1704 * sweep through and kill all deleted sessions 1705 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1706 */ 1707 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1708 if ((sp->se_flags & SE_PRESENT) == 0) { 1709 sp->se_flags |= SE_SHUTDOWN; 1710 kill(sp->se_process, SIGHUP); 1711 } 1712 } 1713 1714 return (state_func_t) multi_user; 1715} 1716 1717/* 1718 * Block further logins. 1719 */ 1720static state_func_t 1721catatonia(void) 1722{ 1723 session_t *sp; 1724 1725 for (sp = sessions; sp; sp = sp->se_next) 1726 sp->se_flags |= SE_SHUTDOWN; 1727 1728 return (state_func_t) multi_user; 1729} 1730 1731/* 1732 * Note SIGALRM. 1733 */ 1734static void 1735alrm_handler(int sig) 1736{ 1737 1738 (void)sig; 1739 clang = 1; 1740} 1741 1742/* 1743 * Bring the system down to single user. 1744 */ 1745static state_func_t 1746death(void) 1747{ 1748 int block, blocked; 1749 size_t len; 1750 1751 /* Temporarily block suspend. */ 1752 len = sizeof(blocked); 1753 block = 1; 1754 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1755 &block, sizeof(block)) == -1) 1756 blocked = 0; 1757 1758 /* 1759 * Also revoke the TTY here. Because runshutdown() may reopen 1760 * the TTY whose getty we're killing here, there is no guarantee 1761 * runshutdown() will perform the initial open() call, causing 1762 * the terminal attributes to be misconfigured. 1763 */ 1764 revoke_ttys(); 1765 1766 /* Try to run the rc.shutdown script within a period of time */ 1767 runshutdown(); 1768 1769 /* Unblock suspend if we blocked it. */ 1770 if (!blocked) 1771 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1772 &blocked, sizeof(blocked)); 1773 1774 return (state_func_t) death_single; 1775} 1776 1777/* 1778 * Do what is necessary to reinitialize single user mode or reboot 1779 * from an incomplete state. 1780 */ 1781static state_func_t 1782death_single(void) 1783{ 1784 int i; 1785 pid_t pid; 1786 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1787 1788 revoke(_PATH_CONSOLE); 1789 1790 for (i = 0; i < 2; ++i) { 1791 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1792 return (state_func_t) single_user; 1793 1794 clang = 0; 1795 alarm(DEATH_WATCH); 1796 do 1797 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1798 collect_child(pid); 1799 while (clang == 0 && errno != ECHILD); 1800 1801 if (errno == ECHILD) 1802 return (state_func_t) single_user; 1803 } 1804 1805 warning("some processes would not die; ps axl advised"); 1806 1807 return (state_func_t) single_user; 1808} 1809 1810static void 1811revoke_ttys(void) 1812{ 1813 session_t *sp; 1814 1815 for (sp = sessions; sp; sp = sp->se_next) { 1816 sp->se_flags |= SE_SHUTDOWN; 1817 kill(sp->se_process, SIGHUP); 1818 revoke(sp->se_device); 1819 } 1820} 1821 1822/* 1823 * Run the system shutdown script. 1824 * 1825 * Exit codes: XXX I should document more 1826 * -2 shutdown script terminated abnormally 1827 * -1 fatal error - can't run script 1828 * 0 good. 1829 * >0 some error (exit code) 1830 */ 1831static int 1832runshutdown(void) 1833{ 1834 pid_t pid, wpid; 1835 int status; 1836 int shutdowntimeout; 1837 size_t len; 1838 char *argv[4]; 1839 const char *shell; 1840 struct sigaction sa; 1841 struct stat sb; 1842 1843 /* 1844 * rc.shutdown is optional, so to prevent any unnecessary 1845 * complaints from the shell we simply don't run it if the 1846 * file does not exist. If the stat() here fails for other 1847 * reasons, we'll let the shell complain. 1848 */ 1849 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1850 return 0; 1851 1852 shell = get_shell(); 1853 1854 if ((pid = fork()) == 0) { 1855 sigemptyset(&sa.sa_mask); 1856 sa.sa_flags = 0; 1857 sa.sa_handler = SIG_IGN; 1858 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1859 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1860 1861 open_console(); 1862 1863 char _sh[] = "sh"; 1864 char _reboot[] = "reboot"; 1865 char _single[] = "single"; 1866 char _path_rundown[] = _PATH_RUNDOWN; 1867 1868 argv[0] = _sh; 1869 argv[1] = _path_rundown; 1870 argv[2] = Reboot ? _reboot : _single; 1871 argv[3] = 0; 1872 1873 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1874 1875#ifdef LOGIN_CAP 1876 setprocresources(RESOURCE_RC); 1877#endif 1878 execv(shell, argv); 1879 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1880 _exit(1); /* force single user mode */ 1881 } 1882 1883 if (pid == -1) { 1884 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1885 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1886 continue; 1887 sleep(STALL_TIMEOUT); 1888 return -1; 1889 } 1890 1891 len = sizeof(shutdowntimeout); 1892 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1893 NULL, 0) == -1 || shutdowntimeout < 2) 1894 shutdowntimeout = DEATH_SCRIPT; 1895 alarm(shutdowntimeout); 1896 clang = 0; 1897 /* 1898 * Copied from single_user(). This is a bit paranoid. 1899 * Use the same ALRM handler. 1900 */ 1901 do { 1902 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1903 collect_child(wpid); 1904 if (clang == 1) { 1905 /* we were waiting for the sub-shell */ 1906 kill(wpid, SIGTERM); 1907 warning("timeout expired for %s on %s: %m; going to " 1908 "single user mode", shell, _PATH_RUNDOWN); 1909 return -1; 1910 } 1911 if (wpid == -1) { 1912 if (errno == EINTR) 1913 continue; 1914 warning("wait for %s on %s failed: %m; going to " 1915 "single user mode", shell, _PATH_RUNDOWN); 1916 return -1; 1917 } 1918 if (wpid == pid && WIFSTOPPED(status)) { 1919 warning("init: %s on %s stopped, restarting\n", 1920 shell, _PATH_RUNDOWN); 1921 kill(pid, SIGCONT); 1922 wpid = -1; 1923 } 1924 } while (wpid != pid && !clang); 1925 1926 /* Turn off the alarm */ 1927 alarm(0); 1928 1929 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1930 requested_transition == catatonia) { 1931 /* 1932 * /etc/rc.shutdown executed /sbin/reboot; 1933 * wait for the end quietly 1934 */ 1935 sigset_t s; 1936 1937 sigfillset(&s); 1938 for (;;) 1939 sigsuspend(&s); 1940 } 1941 1942 if (!WIFEXITED(status)) { 1943 warning("%s on %s terminated abnormally, going to " 1944 "single user mode", shell, _PATH_RUNDOWN); 1945 return -2; 1946 } 1947 1948 if ((status = WEXITSTATUS(status)) != 0) 1949 warning("%s returned status %d", _PATH_RUNDOWN, status); 1950 1951 return status; 1952} 1953 1954static char * 1955strk(char *p) 1956{ 1957 static char *t; 1958 char *q; 1959 int c; 1960 1961 if (p) 1962 t = p; 1963 if (!t) 1964 return 0; 1965 1966 c = *t; 1967 while (c == ' ' || c == '\t' ) 1968 c = *++t; 1969 if (!c) { 1970 t = 0; 1971 return 0; 1972 } 1973 q = t; 1974 if (c == '\'') { 1975 c = *++t; 1976 q = t; 1977 while (c && c != '\'') 1978 c = *++t; 1979 if (!c) /* unterminated string */ 1980 q = t = 0; 1981 else 1982 *t++ = 0; 1983 } else { 1984 while (c && c != ' ' && c != '\t' ) 1985 c = *++t; 1986 *t++ = 0; 1987 if (!c) 1988 t = 0; 1989 } 1990 return q; 1991} 1992 1993#ifdef LOGIN_CAP 1994static void 1995setprocresources(const char *cname) 1996{ 1997 login_cap_t *lc; 1998 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 1999 setusercontext(lc, (struct passwd*)NULL, 0, 2000 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2001 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2002 login_close(lc); 2003 } 2004} 2005#endif 2006