init.c revision 308036
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 308036 2016-10-28 12:58:40Z 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; 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 close(fd); 664 return (error); 665 } 666 667 bufsize = sb.st_size; 668 buf = malloc(bufsize); 669 if (buf == NULL) { 670 emergency("malloc: %s", strerror(errno)); 671 close(fd); 672 return (error); 673 } 674 675 nbytes = read(fd, buf, bufsize); 676 if (nbytes != (ssize_t)bufsize) { 677 emergency("read: %s", strerror(errno)); 678 close(fd); 679 free(buf); 680 return (error); 681 } 682 683 error = close(fd); 684 if (error != 0) { 685 emergency("close: %s", strerror(errno)); 686 free(buf); 687 return (error); 688 } 689 690 *bufp = buf; 691 *bufsizep = bufsize; 692 693 return (0); 694} 695 696static int 697create_file(const char *path, const void *buf, size_t bufsize) 698{ 699 ssize_t nbytes; 700 int error, fd; 701 702 fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0700); 703 if (fd < 0) { 704 emergency("%s: %s", path, strerror(errno)); 705 return (-1); 706 } 707 708 nbytes = write(fd, buf, bufsize); 709 if (nbytes != (ssize_t)bufsize) { 710 emergency("write: %s", strerror(errno)); 711 close(fd); 712 return (-1); 713 } 714 715 error = close(fd); 716 if (error != 0) { 717 emergency("close: %s", strerror(errno)); 718 return (-1); 719 } 720 721 return (0); 722} 723 724static int 725mount_tmpfs(const char *fspath) 726{ 727 struct iovec *iov; 728 char errmsg[255]; 729 int error, iovlen; 730 731 iov = NULL; 732 iovlen = 0; 733 memset(errmsg, 0, sizeof(errmsg)); 734 build_iovec(&iov, &iovlen, "fstype", 735 __DECONST(void *, "tmpfs"), (size_t)-1); 736 build_iovec(&iov, &iovlen, "fspath", 737 __DECONST(void *, fspath), (size_t)-1); 738 build_iovec(&iov, &iovlen, "errmsg", 739 errmsg, sizeof(errmsg)); 740 741 error = nmount(iov, iovlen, 0); 742 if (error != 0) { 743 if (*errmsg != '\0') { 744 emergency("cannot mount tmpfs on %s: %s: %s", 745 fspath, errmsg, strerror(errno)); 746 } else { 747 emergency("cannot mount tmpfs on %s: %s", 748 fspath, strerror(errno)); 749 } 750 return (error); 751 } 752 return (0); 753} 754 755static state_func_t 756reroot(void) 757{ 758 void *buf; 759 char init_path[PATH_MAX]; 760 size_t bufsize, init_path_len; 761 int error, name[4]; 762 763 buf = NULL; 764 bufsize = 0; 765 766 name[0] = CTL_KERN; 767 name[1] = KERN_PROC; 768 name[2] = KERN_PROC_PATHNAME; 769 name[3] = -1; 770 init_path_len = sizeof(init_path); 771 error = sysctl(name, 4, init_path, &init_path_len, NULL, 0); 772 if (error != 0) { 773 emergency("failed to get kern.proc.pathname: %s", 774 strerror(errno)); 775 goto out; 776 } 777 778 revoke_ttys(); 779 runshutdown(); 780 781 /* 782 * Make sure nobody can interfere with our scheme. 783 */ 784 error = kill(-1, SIGKILL); 785 if (error != 0) { 786 emergency("kill(2) failed: %s", strerror(errno)); 787 goto out; 788 } 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 free(buf); 813 return (state_func_t) single_user; 814} 815 816static state_func_t 817reroot_phase_two(void) 818{ 819 char init_path[PATH_MAX], *path, *path_component; 820 size_t init_path_len; 821 int nbytes, error; 822 823 /* 824 * Ask the kernel to mount the new rootfs. 825 */ 826 error = reboot(RB_REROOT); 827 if (error != 0) { 828 emergency("RB_REBOOT failed: %s", strerror(errno)); 829 goto out; 830 } 831 832 /* 833 * Figure out where the destination init(8) binary is. Note that 834 * the path could be different than what we've started with. Use 835 * the value from kenv, if set, or the one from sysctl otherwise. 836 * The latter defaults to a hardcoded value, but can be overridden 837 * by a build time option. 838 */ 839 nbytes = kenv(KENV_GET, "init_path", init_path, sizeof(init_path)); 840 if (nbytes <= 0) { 841 init_path_len = sizeof(init_path); 842 error = sysctlbyname("kern.init_path", 843 init_path, &init_path_len, NULL, 0); 844 if (error != 0) { 845 emergency("failed to retrieve kern.init_path: %s", 846 strerror(errno)); 847 goto out; 848 } 849 } 850 851 /* 852 * Repeat the init search logic from sys/kern/init_path.c 853 */ 854 path_component = init_path; 855 while ((path = strsep(&path_component, ":")) != NULL) { 856 /* 857 * Execute init(8) from the new rootfs. 858 */ 859 execl(path, path, NULL); 860 } 861 emergency("cannot exec init from %s: %s", init_path, strerror(errno)); 862 863out: 864 emergency("reroot failed; going to single user mode"); 865 return (state_func_t) single_user; 866} 867 868/* 869 * Bring the system up single user. 870 */ 871static state_func_t 872single_user(void) 873{ 874 pid_t pid, wpid; 875 int status; 876 sigset_t mask; 877 const char *shell; 878 char *argv[2]; 879 struct timeval tv, tn; 880#ifdef SECURE 881 struct ttyent *typ; 882 struct passwd *pp; 883 static const char banner[] = 884 "Enter root password, or ^D to go multi-user\n"; 885 char *clear, *password; 886#endif 887#ifdef DEBUGSHELL 888 char altshell[128]; 889#endif 890 891 if (Reboot) { 892 /* Instead of going single user, let's reboot the machine */ 893 sync(); 894 reboot(howto); 895 _exit(0); 896 } 897 898 shell = get_shell(); 899 900 if ((pid = fork()) == 0) { 901 /* 902 * Start the single user session. 903 */ 904 open_console(); 905 906#ifdef SECURE 907 /* 908 * Check the root password. 909 * We don't care if the console is 'on' by default; 910 * it's the only tty that can be 'off' and 'secure'. 911 */ 912 typ = getttynam("console"); 913 pp = getpwnam("root"); 914 if (typ && (typ->ty_status & TTY_SECURE) == 0 && 915 pp && *pp->pw_passwd) { 916 write_stderr(banner); 917 for (;;) { 918 clear = getpass("Password:"); 919 if (clear == 0 || *clear == '\0') 920 _exit(0); 921 password = crypt(clear, pp->pw_passwd); 922 bzero(clear, _PASSWORD_LEN); 923 if (password == NULL || 924 strcmp(password, pp->pw_passwd) == 0) 925 break; 926 warning("single-user login failed\n"); 927 } 928 } 929 endttyent(); 930 endpwent(); 931#endif /* SECURE */ 932 933#ifdef DEBUGSHELL 934 { 935 char *cp = altshell; 936 int num; 937 938#define SHREQUEST "Enter full pathname of shell or RETURN for " 939 write_stderr(SHREQUEST); 940 write_stderr(shell); 941 write_stderr(": "); 942 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 943 num != 0 && *cp != '\n' && cp < &altshell[127]) 944 cp++; 945 *cp = '\0'; 946 if (altshell[0] != '\0') 947 shell = altshell; 948 } 949#endif /* DEBUGSHELL */ 950 951 /* 952 * Unblock signals. 953 * We catch all the interesting ones, 954 * and those are reset to SIG_DFL on exec. 955 */ 956 sigemptyset(&mask); 957 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 958 959 /* 960 * Fire off a shell. 961 * If the default one doesn't work, try the Bourne shell. 962 */ 963 964 char name[] = "-sh"; 965 966 argv[0] = name; 967 argv[1] = 0; 968 execv(shell, argv); 969 emergency("can't exec %s for single user: %m", shell); 970 execv(_PATH_BSHELL, argv); 971 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 972 sleep(STALL_TIMEOUT); 973 _exit(1); 974 } 975 976 if (pid == -1) { 977 /* 978 * We are seriously hosed. Do our best. 979 */ 980 emergency("can't fork single-user shell, trying again"); 981 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 982 continue; 983 return (state_func_t) single_user; 984 } 985 986 requested_transition = 0; 987 do { 988 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 989 collect_child(wpid); 990 if (wpid == -1) { 991 if (errno == EINTR) 992 continue; 993 warning("wait for single-user shell failed: %m; restarting"); 994 return (state_func_t) single_user; 995 } 996 if (wpid == pid && WIFSTOPPED(status)) { 997 warning("init: shell stopped, restarting\n"); 998 kill(pid, SIGCONT); 999 wpid = -1; 1000 } 1001 } while (wpid != pid && !requested_transition); 1002 1003 if (requested_transition) 1004 return (state_func_t) requested_transition; 1005 1006 if (!WIFEXITED(status)) { 1007 if (WTERMSIG(status) == SIGKILL) { 1008 /* 1009 * reboot(8) killed shell? 1010 */ 1011 warning("single user shell terminated."); 1012 gettimeofday(&tv, NULL); 1013 tn = tv; 1014 tv.tv_sec += STALL_TIMEOUT; 1015 while (tv.tv_sec > tn.tv_sec || (tv.tv_sec == 1016 tn.tv_sec && tv.tv_usec > tn.tv_usec)) { 1017 sleep(1); 1018 gettimeofday(&tn, NULL); 1019 } 1020 _exit(0); 1021 } else { 1022 warning("single user shell terminated, restarting"); 1023 return (state_func_t) single_user; 1024 } 1025 } 1026 1027 runcom_mode = FASTBOOT; 1028 return (state_func_t) runcom; 1029} 1030 1031/* 1032 * Run the system startup script. 1033 */ 1034static state_func_t 1035runcom(void) 1036{ 1037 state_func_t next_transition; 1038 1039 if ((next_transition = run_script(_PATH_RUNCOM)) != 0) 1040 return next_transition; 1041 1042 runcom_mode = AUTOBOOT; /* the default */ 1043 return (state_func_t) read_ttys; 1044} 1045 1046/* 1047 * Run a shell script. 1048 * Returns 0 on success, otherwise the next transition to enter: 1049 * - single_user if fork/execv/waitpid failed, or if the script 1050 * terminated with a signal or exit code != 0. 1051 * - death_single if a SIGTERM was delivered to init(8). 1052 */ 1053static state_func_t 1054run_script(const char *script) 1055{ 1056 pid_t pid, wpid; 1057 int status; 1058 char *argv[4]; 1059 const char *shell; 1060 struct sigaction sa; 1061 1062 shell = get_shell(); 1063 1064 if ((pid = fork()) == 0) { 1065 sigemptyset(&sa.sa_mask); 1066 sa.sa_flags = 0; 1067 sa.sa_handler = SIG_IGN; 1068 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1069 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1070 1071 open_console(); 1072 1073 char _sh[] = "sh"; 1074 char _autoboot[] = "autoboot"; 1075 1076 argv[0] = _sh; 1077 argv[1] = __DECONST(char *, script); 1078 argv[2] = runcom_mode == AUTOBOOT ? _autoboot : 0; 1079 argv[3] = 0; 1080 1081 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1082 1083#ifdef LOGIN_CAP 1084 setprocresources(RESOURCE_RC); 1085#endif 1086 execv(shell, argv); 1087 stall("can't exec %s for %s: %m", shell, script); 1088 _exit(1); /* force single user mode */ 1089 } 1090 1091 if (pid == -1) { 1092 emergency("can't fork for %s on %s: %m", shell, script); 1093 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1094 continue; 1095 sleep(STALL_TIMEOUT); 1096 return (state_func_t) single_user; 1097 } 1098 1099 /* 1100 * Copied from single_user(). This is a bit paranoid. 1101 */ 1102 requested_transition = 0; 1103 do { 1104 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1105 collect_child(wpid); 1106 if (wpid == -1) { 1107 if (requested_transition == death_single || 1108 requested_transition == reroot) 1109 return (state_func_t) requested_transition; 1110 if (errno == EINTR) 1111 continue; 1112 warning("wait for %s on %s failed: %m; going to " 1113 "single user mode", shell, script); 1114 return (state_func_t) single_user; 1115 } 1116 if (wpid == pid && WIFSTOPPED(status)) { 1117 warning("init: %s on %s stopped, restarting\n", 1118 shell, script); 1119 kill(pid, SIGCONT); 1120 wpid = -1; 1121 } 1122 } while (wpid != pid); 1123 1124 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1125 requested_transition == catatonia) { 1126 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 1127 sigset_t s; 1128 1129 sigfillset(&s); 1130 for (;;) 1131 sigsuspend(&s); 1132 } 1133 1134 if (!WIFEXITED(status)) { 1135 warning("%s on %s terminated abnormally, going to single " 1136 "user mode", shell, script); 1137 return (state_func_t) single_user; 1138 } 1139 1140 if (WEXITSTATUS(status)) 1141 return (state_func_t) single_user; 1142 1143 return (state_func_t) 0; 1144} 1145 1146/* 1147 * Open the session database. 1148 * 1149 * NB: We could pass in the size here; is it necessary? 1150 */ 1151static int 1152start_session_db(void) 1153{ 1154 if (session_db && (*session_db->close)(session_db)) 1155 emergency("session database close: %s", strerror(errno)); 1156 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 1157 emergency("session database open: %s", strerror(errno)); 1158 return (1); 1159 } 1160 return (0); 1161 1162} 1163 1164/* 1165 * Add a new login session. 1166 */ 1167static void 1168add_session(session_t *sp) 1169{ 1170 DBT key; 1171 DBT data; 1172 1173 key.data = &sp->se_process; 1174 key.size = sizeof sp->se_process; 1175 data.data = &sp; 1176 data.size = sizeof sp; 1177 1178 if ((*session_db->put)(session_db, &key, &data, 0)) 1179 emergency("insert %d: %s", sp->se_process, strerror(errno)); 1180} 1181 1182/* 1183 * Delete an old login session. 1184 */ 1185static void 1186del_session(session_t *sp) 1187{ 1188 DBT key; 1189 1190 key.data = &sp->se_process; 1191 key.size = sizeof sp->se_process; 1192 1193 if ((*session_db->del)(session_db, &key, 0)) 1194 emergency("delete %d: %s", sp->se_process, strerror(errno)); 1195} 1196 1197/* 1198 * Look up a login session by pid. 1199 */ 1200static session_t * 1201find_session(pid_t pid) 1202{ 1203 DBT key; 1204 DBT data; 1205 session_t *ret; 1206 1207 key.data = &pid; 1208 key.size = sizeof pid; 1209 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 1210 return 0; 1211 bcopy(data.data, (char *)&ret, sizeof(ret)); 1212 return ret; 1213} 1214 1215/* 1216 * Construct an argument vector from a command line. 1217 */ 1218static char ** 1219construct_argv(char *command) 1220{ 1221 int argc = 0; 1222 char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 1223 * sizeof (char *)); 1224 1225 if ((argv[argc++] = strk(command)) == 0) { 1226 free(argv); 1227 return (NULL); 1228 } 1229 while ((argv[argc++] = strk((char *) 0)) != NULL) 1230 continue; 1231 return argv; 1232} 1233 1234/* 1235 * Deallocate a session descriptor. 1236 */ 1237static void 1238free_session(session_t *sp) 1239{ 1240 free(sp->se_device); 1241 if (sp->se_getty) { 1242 free(sp->se_getty); 1243 free(sp->se_getty_argv_space); 1244 free(sp->se_getty_argv); 1245 } 1246 if (sp->se_window) { 1247 free(sp->se_window); 1248 free(sp->se_window_argv_space); 1249 free(sp->se_window_argv); 1250 } 1251 if (sp->se_type) 1252 free(sp->se_type); 1253 free(sp); 1254} 1255 1256/* 1257 * Allocate a new session descriptor. 1258 * Mark it SE_PRESENT. 1259 */ 1260static session_t * 1261new_session(session_t *sprev, int session_index, struct ttyent *typ) 1262{ 1263 session_t *sp; 1264 int fd; 1265 1266 if ((typ->ty_status & TTY_ON) == 0 || 1267 typ->ty_name == 0 || 1268 typ->ty_getty == 0) 1269 return 0; 1270 1271 sp = (session_t *) calloc(1, sizeof (session_t)); 1272 1273 sp->se_index = session_index; 1274 sp->se_flags |= SE_PRESENT; 1275 1276 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 1277 sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 1278 1279 /* 1280 * Attempt to open the device, if we get "device not configured" 1281 * then don't add the device to the session list. 1282 */ 1283 if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) { 1284 if (errno == ENXIO) { 1285 free_session(sp); 1286 return (0); 1287 } 1288 } else 1289 close(fd); 1290 1291 if (setupargv(sp, typ) == 0) { 1292 free_session(sp); 1293 return (0); 1294 } 1295 1296 sp->se_next = 0; 1297 if (sprev == 0) { 1298 sessions = sp; 1299 sp->se_prev = 0; 1300 } else { 1301 sprev->se_next = sp; 1302 sp->se_prev = sprev; 1303 } 1304 1305 return sp; 1306} 1307 1308/* 1309 * Calculate getty and if useful window argv vectors. 1310 */ 1311static int 1312setupargv(session_t *sp, struct ttyent *typ) 1313{ 1314 1315 if (sp->se_getty) { 1316 free(sp->se_getty); 1317 free(sp->se_getty_argv_space); 1318 free(sp->se_getty_argv); 1319 } 1320 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 1321 sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 1322 sp->se_getty_argv_space = strdup(sp->se_getty); 1323 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 1324 if (sp->se_getty_argv == 0) { 1325 warning("can't parse getty for port %s", sp->se_device); 1326 free(sp->se_getty); 1327 free(sp->se_getty_argv_space); 1328 sp->se_getty = sp->se_getty_argv_space = 0; 1329 return (0); 1330 } 1331 if (sp->se_window) { 1332 free(sp->se_window); 1333 free(sp->se_window_argv_space); 1334 free(sp->se_window_argv); 1335 } 1336 sp->se_window = sp->se_window_argv_space = 0; 1337 sp->se_window_argv = 0; 1338 if (typ->ty_window) { 1339 sp->se_window = strdup(typ->ty_window); 1340 sp->se_window_argv_space = strdup(sp->se_window); 1341 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1342 if (sp->se_window_argv == 0) { 1343 warning("can't parse window for port %s", 1344 sp->se_device); 1345 free(sp->se_window_argv_space); 1346 free(sp->se_window); 1347 sp->se_window = sp->se_window_argv_space = 0; 1348 return (0); 1349 } 1350 } 1351 if (sp->se_type) 1352 free(sp->se_type); 1353 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1354 return (1); 1355} 1356 1357/* 1358 * Walk the list of ttys and create sessions for each active line. 1359 */ 1360static state_func_t 1361read_ttys(void) 1362{ 1363 int session_index = 0; 1364 session_t *sp, *snext; 1365 struct ttyent *typ; 1366 1367 /* 1368 * Destroy any previous session state. 1369 * There shouldn't be any, but just in case... 1370 */ 1371 for (sp = sessions; sp; sp = snext) { 1372 snext = sp->se_next; 1373 free_session(sp); 1374 } 1375 sessions = 0; 1376 if (start_session_db()) 1377 return (state_func_t) single_user; 1378 1379 /* 1380 * Allocate a session entry for each active port. 1381 * Note that sp starts at 0. 1382 */ 1383 while ((typ = getttyent()) != NULL) 1384 if ((snext = new_session(sp, ++session_index, typ)) != NULL) 1385 sp = snext; 1386 1387 endttyent(); 1388 1389 return (state_func_t) multi_user; 1390} 1391 1392/* 1393 * Start a window system running. 1394 */ 1395static void 1396start_window_system(session_t *sp) 1397{ 1398 pid_t pid; 1399 sigset_t mask; 1400 char term[64], *env[2]; 1401 int status; 1402 1403 if ((pid = fork()) == -1) { 1404 emergency("can't fork for window system on port %s: %m", 1405 sp->se_device); 1406 /* hope that getty fails and we can try again */ 1407 return; 1408 } 1409 if (pid) { 1410 waitpid(-1, &status, 0); 1411 return; 1412 } 1413 1414 /* reparent window process to the init to not make a zombie on exit */ 1415 if ((pid = fork()) == -1) { 1416 emergency("can't fork for window system on port %s: %m", 1417 sp->se_device); 1418 _exit(1); 1419 } 1420 if (pid) 1421 _exit(0); 1422 1423 sigemptyset(&mask); 1424 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1425 1426 if (setsid() < 0) 1427 emergency("setsid failed (window) %m"); 1428 1429#ifdef LOGIN_CAP 1430 setprocresources(RESOURCE_WINDOW); 1431#endif 1432 if (sp->se_type) { 1433 /* Don't use malloc after fork */ 1434 strcpy(term, "TERM="); 1435 strncat(term, sp->se_type, sizeof(term) - 6); 1436 env[0] = term; 1437 env[1] = 0; 1438 } 1439 else 1440 env[0] = 0; 1441 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1442 stall("can't exec window system '%s' for port %s: %m", 1443 sp->se_window_argv[0], sp->se_device); 1444 _exit(1); 1445} 1446 1447/* 1448 * Start a login session running. 1449 */ 1450static pid_t 1451start_getty(session_t *sp) 1452{ 1453 pid_t pid; 1454 sigset_t mask; 1455 time_t current_time = time((time_t *) 0); 1456 int too_quick = 0; 1457 char term[64], *env[2]; 1458 1459 if (current_time >= sp->se_started && 1460 current_time - sp->se_started < GETTY_SPACING) { 1461 if (++sp->se_nspace > GETTY_NSPACE) { 1462 sp->se_nspace = 0; 1463 too_quick = 1; 1464 } 1465 } else 1466 sp->se_nspace = 0; 1467 1468 /* 1469 * fork(), not vfork() -- we can't afford to block. 1470 */ 1471 if ((pid = fork()) == -1) { 1472 emergency("can't fork for getty on port %s: %m", sp->se_device); 1473 return -1; 1474 } 1475 1476 if (pid) 1477 return pid; 1478 1479 if (too_quick) { 1480 warning("getty repeating too quickly on port %s, sleeping %d secs", 1481 sp->se_device, GETTY_SLEEP); 1482 sleep((unsigned) GETTY_SLEEP); 1483 } 1484 1485 if (sp->se_window) { 1486 start_window_system(sp); 1487 sleep(WINDOW_WAIT); 1488 } 1489 1490 sigemptyset(&mask); 1491 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1492 1493#ifdef LOGIN_CAP 1494 setprocresources(RESOURCE_GETTY); 1495#endif 1496 if (sp->se_type) { 1497 /* Don't use malloc after fork */ 1498 strcpy(term, "TERM="); 1499 strncat(term, sp->se_type, sizeof(term) - 6); 1500 env[0] = term; 1501 env[1] = 0; 1502 } else 1503 env[0] = 0; 1504 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1505 stall("can't exec getty '%s' for port %s: %m", 1506 sp->se_getty_argv[0], sp->se_device); 1507 _exit(1); 1508} 1509 1510/* 1511 * Collect exit status for a child. 1512 * If an exiting login, start a new login running. 1513 */ 1514static void 1515collect_child(pid_t pid) 1516{ 1517 session_t *sp, *sprev, *snext; 1518 1519 if (! sessions) 1520 return; 1521 1522 if (! (sp = find_session(pid))) 1523 return; 1524 1525 del_session(sp); 1526 sp->se_process = 0; 1527 1528 if (sp->se_flags & SE_SHUTDOWN) { 1529 if ((sprev = sp->se_prev) != NULL) 1530 sprev->se_next = sp->se_next; 1531 else 1532 sessions = sp->se_next; 1533 if ((snext = sp->se_next) != NULL) 1534 snext->se_prev = sp->se_prev; 1535 free_session(sp); 1536 return; 1537 } 1538 1539 if ((pid = start_getty(sp)) == -1) { 1540 /* serious trouble */ 1541 requested_transition = clean_ttys; 1542 return; 1543 } 1544 1545 sp->se_process = pid; 1546 sp->se_started = time((time_t *) 0); 1547 add_session(sp); 1548} 1549 1550/* 1551 * Catch a signal and request a state transition. 1552 */ 1553static void 1554transition_handler(int sig) 1555{ 1556 1557 switch (sig) { 1558 case SIGHUP: 1559 if (current_state == read_ttys || current_state == multi_user || 1560 current_state == clean_ttys || current_state == catatonia) 1561 requested_transition = clean_ttys; 1562 break; 1563 case SIGUSR2: 1564 howto = RB_POWEROFF; 1565 case SIGUSR1: 1566 howto |= RB_HALT; 1567 case SIGINT: 1568 Reboot = TRUE; 1569 case SIGTERM: 1570 if (current_state == read_ttys || current_state == multi_user || 1571 current_state == clean_ttys || current_state == catatonia) 1572 requested_transition = death; 1573 else 1574 requested_transition = death_single; 1575 break; 1576 case SIGTSTP: 1577 if (current_state == runcom || current_state == read_ttys || 1578 current_state == clean_ttys || 1579 current_state == multi_user || current_state == catatonia) 1580 requested_transition = catatonia; 1581 break; 1582 case SIGEMT: 1583 requested_transition = reroot; 1584 break; 1585 default: 1586 requested_transition = 0; 1587 break; 1588 } 1589} 1590 1591/* 1592 * Take the system multiuser. 1593 */ 1594static state_func_t 1595multi_user(void) 1596{ 1597 pid_t pid; 1598 session_t *sp; 1599 1600 requested_transition = 0; 1601 1602 /* 1603 * If the administrator has not set the security level to -1 1604 * to indicate that the kernel should not run multiuser in secure 1605 * mode, and the run script has not set a higher level of security 1606 * than level 1, then put the kernel into secure mode. 1607 */ 1608 if (getsecuritylevel() == 0) 1609 setsecuritylevel(1); 1610 1611 for (sp = sessions; sp; sp = sp->se_next) { 1612 if (sp->se_process) 1613 continue; 1614 if ((pid = start_getty(sp)) == -1) { 1615 /* serious trouble */ 1616 requested_transition = clean_ttys; 1617 break; 1618 } 1619 sp->se_process = pid; 1620 sp->se_started = time((time_t *) 0); 1621 add_session(sp); 1622 } 1623 1624 while (!requested_transition) 1625 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1626 collect_child(pid); 1627 1628 return (state_func_t) requested_transition; 1629} 1630 1631/* 1632 * This is an (n*2)+(n^2) algorithm. We hope it isn't run often... 1633 */ 1634static state_func_t 1635clean_ttys(void) 1636{ 1637 session_t *sp, *sprev; 1638 struct ttyent *typ; 1639 int session_index = 0; 1640 int devlen; 1641 char *old_getty, *old_window, *old_type; 1642 1643 /* 1644 * mark all sessions for death, (!SE_PRESENT) 1645 * as we find or create new ones they'll be marked as keepers, 1646 * we'll later nuke all the ones not found in /etc/ttys 1647 */ 1648 for (sp = sessions; sp != NULL; sp = sp->se_next) 1649 sp->se_flags &= ~SE_PRESENT; 1650 1651 devlen = sizeof(_PATH_DEV) - 1; 1652 while ((typ = getttyent()) != NULL) { 1653 ++session_index; 1654 1655 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1656 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1657 break; 1658 1659 if (sp) { 1660 /* we want this one to live */ 1661 sp->se_flags |= SE_PRESENT; 1662 if (sp->se_index != session_index) { 1663 warning("port %s changed utmp index from %d to %d", 1664 sp->se_device, sp->se_index, 1665 session_index); 1666 sp->se_index = session_index; 1667 } 1668 if ((typ->ty_status & TTY_ON) == 0 || 1669 typ->ty_getty == 0) { 1670 sp->se_flags |= SE_SHUTDOWN; 1671 kill(sp->se_process, SIGHUP); 1672 continue; 1673 } 1674 sp->se_flags &= ~SE_SHUTDOWN; 1675 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1676 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1677 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1678 if (setupargv(sp, typ) == 0) { 1679 warning("can't parse getty for port %s", 1680 sp->se_device); 1681 sp->se_flags |= SE_SHUTDOWN; 1682 kill(sp->se_process, SIGHUP); 1683 } 1684 else if ( !old_getty 1685 || (!old_type && sp->se_type) 1686 || (old_type && !sp->se_type) 1687 || (!old_window && sp->se_window) 1688 || (old_window && !sp->se_window) 1689 || (strcmp(old_getty, sp->se_getty) != 0) 1690 || (old_window && strcmp(old_window, sp->se_window) != 0) 1691 || (old_type && strcmp(old_type, sp->se_type) != 0) 1692 ) { 1693 /* Don't set SE_SHUTDOWN here */ 1694 sp->se_nspace = 0; 1695 sp->se_started = 0; 1696 kill(sp->se_process, SIGHUP); 1697 } 1698 if (old_getty) 1699 free(old_getty); 1700 if (old_window) 1701 free(old_window); 1702 if (old_type) 1703 free(old_type); 1704 continue; 1705 } 1706 1707 new_session(sprev, session_index, typ); 1708 } 1709 1710 endttyent(); 1711 1712 /* 1713 * sweep through and kill all deleted sessions 1714 * ones who's /etc/ttys line was deleted (SE_PRESENT unset) 1715 */ 1716 for (sp = sessions; sp != NULL; sp = sp->se_next) { 1717 if ((sp->se_flags & SE_PRESENT) == 0) { 1718 sp->se_flags |= SE_SHUTDOWN; 1719 kill(sp->se_process, SIGHUP); 1720 } 1721 } 1722 1723 return (state_func_t) multi_user; 1724} 1725 1726/* 1727 * Block further logins. 1728 */ 1729static state_func_t 1730catatonia(void) 1731{ 1732 session_t *sp; 1733 1734 for (sp = sessions; sp; sp = sp->se_next) 1735 sp->se_flags |= SE_SHUTDOWN; 1736 1737 return (state_func_t) multi_user; 1738} 1739 1740/* 1741 * Note SIGALRM. 1742 */ 1743static void 1744alrm_handler(int sig) 1745{ 1746 1747 (void)sig; 1748 clang = 1; 1749} 1750 1751/* 1752 * Bring the system down to single user. 1753 */ 1754static state_func_t 1755death(void) 1756{ 1757 int block, blocked; 1758 size_t len; 1759 1760 /* Temporarily block suspend. */ 1761 len = sizeof(blocked); 1762 block = 1; 1763 if (sysctlbyname("kern.suspend_blocked", &blocked, &len, 1764 &block, sizeof(block)) == -1) 1765 blocked = 0; 1766 1767 /* 1768 * Also revoke the TTY here. Because runshutdown() may reopen 1769 * the TTY whose getty we're killing here, there is no guarantee 1770 * runshutdown() will perform the initial open() call, causing 1771 * the terminal attributes to be misconfigured. 1772 */ 1773 revoke_ttys(); 1774 1775 /* Try to run the rc.shutdown script within a period of time */ 1776 runshutdown(); 1777 1778 /* Unblock suspend if we blocked it. */ 1779 if (!blocked) 1780 sysctlbyname("kern.suspend_blocked", NULL, NULL, 1781 &blocked, sizeof(blocked)); 1782 1783 return (state_func_t) death_single; 1784} 1785 1786/* 1787 * Do what is necessary to reinitialize single user mode or reboot 1788 * from an incomplete state. 1789 */ 1790static state_func_t 1791death_single(void) 1792{ 1793 int i; 1794 pid_t pid; 1795 static const int death_sigs[2] = { SIGTERM, SIGKILL }; 1796 1797 revoke(_PATH_CONSOLE); 1798 1799 for (i = 0; i < 2; ++i) { 1800 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1801 return (state_func_t) single_user; 1802 1803 clang = 0; 1804 alarm(DEATH_WATCH); 1805 do 1806 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1807 collect_child(pid); 1808 while (clang == 0 && errno != ECHILD); 1809 1810 if (errno == ECHILD) 1811 return (state_func_t) single_user; 1812 } 1813 1814 warning("some processes would not die; ps axl advised"); 1815 1816 return (state_func_t) single_user; 1817} 1818 1819static void 1820revoke_ttys(void) 1821{ 1822 session_t *sp; 1823 1824 for (sp = sessions; sp; sp = sp->se_next) { 1825 sp->se_flags |= SE_SHUTDOWN; 1826 kill(sp->se_process, SIGHUP); 1827 revoke(sp->se_device); 1828 } 1829} 1830 1831/* 1832 * Run the system shutdown script. 1833 * 1834 * Exit codes: XXX I should document more 1835 * -2 shutdown script terminated abnormally 1836 * -1 fatal error - can't run script 1837 * 0 good. 1838 * >0 some error (exit code) 1839 */ 1840static int 1841runshutdown(void) 1842{ 1843 pid_t pid, wpid; 1844 int status; 1845 int shutdowntimeout; 1846 size_t len; 1847 char *argv[4]; 1848 const char *shell; 1849 struct sigaction sa; 1850 struct stat sb; 1851 1852 /* 1853 * rc.shutdown is optional, so to prevent any unnecessary 1854 * complaints from the shell we simply don't run it if the 1855 * file does not exist. If the stat() here fails for other 1856 * reasons, we'll let the shell complain. 1857 */ 1858 if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT) 1859 return 0; 1860 1861 shell = get_shell(); 1862 1863 if ((pid = fork()) == 0) { 1864 sigemptyset(&sa.sa_mask); 1865 sa.sa_flags = 0; 1866 sa.sa_handler = SIG_IGN; 1867 sigaction(SIGTSTP, &sa, (struct sigaction *)0); 1868 sigaction(SIGHUP, &sa, (struct sigaction *)0); 1869 1870 open_console(); 1871 1872 char _sh[] = "sh"; 1873 char _reboot[] = "reboot"; 1874 char _single[] = "single"; 1875 char _path_rundown[] = _PATH_RUNDOWN; 1876 1877 argv[0] = _sh; 1878 argv[1] = _path_rundown; 1879 argv[2] = Reboot ? _reboot : _single; 1880 argv[3] = 0; 1881 1882 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 1883 1884#ifdef LOGIN_CAP 1885 setprocresources(RESOURCE_RC); 1886#endif 1887 execv(shell, argv); 1888 warning("can't exec %s for %s: %m", shell, _PATH_RUNDOWN); 1889 _exit(1); /* force single user mode */ 1890 } 1891 1892 if (pid == -1) { 1893 emergency("can't fork for %s on %s: %m", shell, _PATH_RUNDOWN); 1894 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 1895 continue; 1896 sleep(STALL_TIMEOUT); 1897 return -1; 1898 } 1899 1900 len = sizeof(shutdowntimeout); 1901 if (sysctlbyname("kern.init_shutdown_timeout", &shutdowntimeout, &len, 1902 NULL, 0) == -1 || shutdowntimeout < 2) 1903 shutdowntimeout = DEATH_SCRIPT; 1904 alarm(shutdowntimeout); 1905 clang = 0; 1906 /* 1907 * Copied from single_user(). This is a bit paranoid. 1908 * Use the same ALRM handler. 1909 */ 1910 do { 1911 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 1912 collect_child(wpid); 1913 if (clang == 1) { 1914 /* we were waiting for the sub-shell */ 1915 kill(wpid, SIGTERM); 1916 warning("timeout expired for %s on %s: %m; going to " 1917 "single user mode", shell, _PATH_RUNDOWN); 1918 return -1; 1919 } 1920 if (wpid == -1) { 1921 if (errno == EINTR) 1922 continue; 1923 warning("wait for %s on %s failed: %m; going to " 1924 "single user mode", shell, _PATH_RUNDOWN); 1925 return -1; 1926 } 1927 if (wpid == pid && WIFSTOPPED(status)) { 1928 warning("init: %s on %s stopped, restarting\n", 1929 shell, _PATH_RUNDOWN); 1930 kill(pid, SIGCONT); 1931 wpid = -1; 1932 } 1933 } while (wpid != pid && !clang); 1934 1935 /* Turn off the alarm */ 1936 alarm(0); 1937 1938 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 1939 requested_transition == catatonia) { 1940 /* 1941 * /etc/rc.shutdown executed /sbin/reboot; 1942 * wait for the end quietly 1943 */ 1944 sigset_t s; 1945 1946 sigfillset(&s); 1947 for (;;) 1948 sigsuspend(&s); 1949 } 1950 1951 if (!WIFEXITED(status)) { 1952 warning("%s on %s terminated abnormally, going to " 1953 "single user mode", shell, _PATH_RUNDOWN); 1954 return -2; 1955 } 1956 1957 if ((status = WEXITSTATUS(status)) != 0) 1958 warning("%s returned status %d", _PATH_RUNDOWN, status); 1959 1960 return status; 1961} 1962 1963static char * 1964strk(char *p) 1965{ 1966 static char *t; 1967 char *q; 1968 int c; 1969 1970 if (p) 1971 t = p; 1972 if (!t) 1973 return 0; 1974 1975 c = *t; 1976 while (c == ' ' || c == '\t' ) 1977 c = *++t; 1978 if (!c) { 1979 t = 0; 1980 return 0; 1981 } 1982 q = t; 1983 if (c == '\'') { 1984 c = *++t; 1985 q = t; 1986 while (c && c != '\'') 1987 c = *++t; 1988 if (!c) /* unterminated string */ 1989 q = t = 0; 1990 else 1991 *t++ = 0; 1992 } else { 1993 while (c && c != ' ' && c != '\t' ) 1994 c = *++t; 1995 *t++ = 0; 1996 if (!c) 1997 t = 0; 1998 } 1999 return q; 2000} 2001 2002#ifdef LOGIN_CAP 2003static void 2004setprocresources(const char *cname) 2005{ 2006 login_cap_t *lc; 2007 if ((lc = login_getclassbyname(cname, NULL)) != NULL) { 2008 setusercontext(lc, (struct passwd*)NULL, 0, 2009 LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | 2010 LOGIN_SETLOGINCLASS | LOGIN_SETCPUMASK); 2011 login_close(lc); 2012 } 2013} 2014#endif 2015