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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1991, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93"; 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/mount.h> 49 #include <sys/sysctl.h> 50 #include <sys/wait.h> 51 52 #include <db.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <signal.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <syslog.h> 60 #include <time.h> 61 #include <ttyent.h> 62 #include <unistd.h> 63 #include <sys/reboot.h> 64 65 #ifdef __STDC__ 66 #include <stdarg.h> 67 #else 68 #include <varargs.h> 69 #endif 70 71 #ifdef SECURE 72 #include <pwd.h> 73 #endif 74 75 #ifdef LOGIN_CAP 76 #include <login_cap.h> 77 #endif 78 79 #include "pathnames.h" 80 81 /* 82 * Until the mythical util.h arrives... 83 */ 84 extern int login_tty __P((int)); 85 extern int logout __P((const char *)); 86 extern void logwtmp __P((const char *, const char *, const char *)); 87 88 /* 89 * Sleep times; used to prevent thrashing. 90 */ 91 #define GETTY_SPACING 5 /* N secs minimum getty spacing */ 92 #define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 93 #define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ 94 #define WINDOW_WAIT 3 /* wait N secs after starting window */ 95 #define STALL_TIMEOUT 30 /* wait N secs after warning */ 96 #define DEATH_WATCH 10 /* wait N secs for procs to die */ 97 #define RESOURCE_RC "daemon" 98 #define RESOURCE_WINDOW "default" 99 #define RESOURCE_GETTY "default" 100 101 void handle __P((sig_t, ...)); 102 void delset __P((sigset_t *, ...)); 103 104 void stall __P((char *, ...)); 105 void warning __P((char *, ...)); 106 void emergency __P((char *, ...)); 107 void disaster __P((int)); 108 void badsys __P((int)); 109 110 /* 111 * We really need a recursive typedef... 112 * The following at least guarantees that the return type of (*state_t)() 113 * is sufficiently wide to hold a function pointer. 114 */ 115 typedef long (*state_func_t) __P((void)); 116 typedef state_func_t (*state_t) __P((void)); 117 118 state_func_t single_user __P((void)); 119 state_func_t runcom __P((void)); 120 state_func_t read_ttys __P((void)); 121 state_func_t multi_user __P((void)); 122 state_func_t clean_ttys __P((void)); 123 state_func_t catatonia __P((void)); 124 state_func_t death __P((void)); 125 126 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 127 #define FALSE 0 128 #define TRUE 1 129 130 int Reboot = FALSE; 131 132 int devfs; 133 134 void transition __P((state_t)); 135 state_t requested_transition = runcom; 136 137 void setctty __P((char *)); 138 139 typedef struct init_session { 140 int se_index; /* index of entry in ttys file */ 141 pid_t se_process; /* controlling process */ 142 time_t se_started; /* used to avoid thrashing */ 143 int se_flags; /* status of session */ 144 #define SE_SHUTDOWN 0x1 /* session won't be restarted */ 145 int se_nspace; /* spacing count */ 146 char *se_device; /* filename of port */ 147 char *se_getty; /* what to run on that port */ 148 char *se_getty_argv_space; /* pre-parsed argument array space */ 149 char **se_getty_argv; /* pre-parsed argument array */ 150 char *se_window; /* window system (started only once) */ 151 char *se_window_argv_space; /* pre-parsed argument array space */ 152 char **se_window_argv; /* pre-parsed argument array */ 153 char *se_type; /* default terminal type */ 154 struct init_session *se_prev; 155 struct init_session *se_next; 156 } session_t; 157 158 void free_session __P((session_t *)); 159 session_t *new_session __P((session_t *, int, struct ttyent *)); 160 session_t *sessions; 161 162 char **construct_argv __P((char *)); 163 void start_window_system __P((session_t *)); 164 void collect_child __P((pid_t)); 165 pid_t start_getty __P((session_t *)); 166 void transition_handler __P((int)); 167 void alrm_handler __P((int)); 168 void setsecuritylevel __P((int)); 169 int getsecuritylevel __P((void)); 170 int setupargv __P((session_t *, struct ttyent *)); 171 #ifdef LOGIN_CAP 172 void setprocresources __P((const char *)); 173 #endif 174 int clang; 175 176 void clear_session_logs __P((session_t *)); 177 178 int start_session_db __P((void)); 179 void add_session __P((session_t *)); 180 void del_session __P((session_t *)); 181 session_t *find_session __P((pid_t)); 182 DB *session_db; 183 184 /* 185 * The mother of all processes. 186 */ 187 int 188 main(argc, argv) 189 int argc; 190 char **argv; 191 { 192 int c; 193 struct sigaction sa; 194 sigset_t mask; 195 196 197 /* Dispose of random users. */ 198 if (getuid() != 0) { 199 (void)fprintf(stderr, "init: %s\n", strerror(EPERM)); 200 exit (1); 201 } 202 203 /* System V users like to reexec init. */ 204 if (getpid() != 1) { 205 (void)fprintf(stderr, "init: already running\n"); 206 exit (1); 207 } 208 209 /* 210 * Note that this does NOT open a file... 211 * Does 'init' deserve its own facility number? 212 */ 213 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH); 214 215 /* 216 * Create an initial session. 217 */ 218 if (setsid() < 0) 219 warning("initial setsid() failed: %m"); 220 221 /* 222 * Establish an initial user so that programs running 223 * single user do not freak out and die (like passwd). 224 */ 225 if (setlogin("root") < 0) 226 warning("setlogin() failed: %m"); 227 228 /* 229 * This code assumes that we always get arguments through flags, 230 * never through bits set in some random machine register. 231 */ 232 while ((c = getopt(argc, argv, "dsf")) != -1) 233 switch (c) { 234 case 'd': 235 devfs = 1; 236 break; 237 case 's': 238 requested_transition = single_user; 239 break; 240 case 'f': 241 runcom_mode = FASTBOOT; 242 break; 243 default: 244 warning("unrecognized flag '-%c'", c); 245 break; 246 } 247 248 if (optind != argc) 249 warning("ignoring excess arguments"); 250 251 /* Mount devfs on /dev */ 252 if (devfs) { 253 mount(MOUNT_DEVFS, "/dev", MNT_NOEXEC|MNT_RDONLY, 0); 254 } 255 256 /* 257 * We catch or block signals rather than ignore them, 258 * so that they get reset on exec. 259 */ 260 handle(badsys, SIGSYS, 0); 261 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, 262 SIGBUS, SIGXCPU, SIGXFSZ, 0); 263 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, 0); 264 handle(alrm_handler, SIGALRM, 0); 265 sigfillset(&mask); 266 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 267 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM, 0); 268 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 269 sigemptyset(&sa.sa_mask); 270 sa.sa_flags = 0; 271 sa.sa_handler = SIG_IGN; 272 (void) sigaction(SIGTTIN, &sa, (struct sigaction *)0); 273 (void) sigaction(SIGTTOU, &sa, (struct sigaction *)0); 274 275 /* 276 * Paranoia. 277 */ 278 close(0); 279 close(1); 280 close(2); 281 282 /* 283 * Start the state machine. 284 */ 285 transition(requested_transition); 286 287 /* 288 * Should never reach here. 289 */ 290 return 1; 291 } 292 293 /* 294 * Associate a function with a signal handler. 295 */ 296 void 297 #ifdef __STDC__ 298 handle(sig_t handler, ...) 299 #else 300 handle(va_alist) 301 va_dcl 302 #endif 303 { 304 int sig; 305 struct sigaction sa; 306 int mask_everything; 307 va_list ap; 308 #ifndef __STDC__ 309 sig_t handler; 310 311 va_start(ap); 312 handler = va_arg(ap, sig_t); 313 #else 314 va_start(ap, handler); 315 #endif 316 317 sa.sa_handler = handler; 318 sigfillset(&mask_everything); 319 320 while (sig = va_arg(ap, int)) { 321 sa.sa_mask = mask_everything; 322 /* XXX SA_RESTART? */ 323 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 324 sigaction(sig, &sa, (struct sigaction *) 0); 325 } 326 va_end(ap); 327 } 328 329 /* 330 * Delete a set of signals from a mask. 331 */ 332 void 333 #ifdef __STDC__ 334 delset(sigset_t *maskp, ...) 335 #else 336 delset(va_alist) 337 va_dcl 338 #endif 339 { 340 int sig; 341 va_list ap; 342 #ifndef __STDC__ 343 sigset_t *maskp; 344 345 va_start(ap); 346 maskp = va_arg(ap, sigset_t *); 347 #else 348 va_start(ap, maskp); 349 #endif 350 351 while (sig = va_arg(ap, int)) 352 sigdelset(maskp, sig); 353 va_end(ap); 354 } 355 356 /* 357 * Log a message and sleep for a while (to give someone an opportunity 358 * to read it and to save log or hardcopy output if the problem is chronic). 359 * NB: should send a message to the session logger to avoid blocking. 360 */ 361 void 362 #ifdef __STDC__ 363 stall(char *message, ...) 364 #else 365 stall(va_alist) 366 va_dcl 367 #endif 368 { 369 va_list ap; 370 #ifndef __STDC__ 371 char *message; 372 373 va_start(ap); 374 message = va_arg(ap, char *); 375 #else 376 va_start(ap, message); 377 #endif 378 379 vsyslog(LOG_ALERT, message, ap); 380 va_end(ap); 381 sleep(STALL_TIMEOUT); 382 } 383 384 /* 385 * Like stall(), but doesn't sleep. 386 * If cpp had variadic macros, the two functions could be #defines for another. 387 * NB: should send a message to the session logger to avoid blocking. 388 */ 389 void 390 #ifdef __STDC__ 391 warning(char *message, ...) 392 #else 393 warning(va_alist) 394 va_dcl 395 #endif 396 { 397 va_list ap; 398 #ifndef __STDC__ 399 char *message; 400 401 va_start(ap); 402 message = va_arg(ap, char *); 403 #else 404 va_start(ap, message); 405 #endif 406 407 vsyslog(LOG_ALERT, message, ap); 408 va_end(ap); 409 } 410 411 /* 412 * Log an emergency message. 413 * NB: should send a message to the session logger to avoid blocking. 414 */ 415 void 416 #ifdef __STDC__ 417 emergency(char *message, ...) 418 #else 419 emergency(va_alist) 420 va_dcl 421 #endif 422 { 423 va_list ap; 424 #ifndef __STDC__ 425 char *message; 426 427 va_start(ap); 428 message = va_arg(ap, char *); 429 #else 430 va_start(ap, message); 431 #endif 432 433 vsyslog(LOG_EMERG, message, ap); 434 va_end(ap); 435 } 436 437 /* 438 * Catch a SIGSYS signal. 439 * 440 * These may arise if a system does not support sysctl. 441 * We tolerate up to 25 of these, then throw in the towel. 442 */ 443 void 444 badsys(sig) 445 int sig; 446 { 447 static int badcount = 0; 448 449 if (badcount++ < 25) 450 return; 451 disaster(sig); 452 } 453 454 /* 455 * Catch an unexpected signal. 456 */ 457 void 458 disaster(sig) 459 int sig; 460 { 461 emergency("fatal signal: %s", 462 sig < (unsigned) NSIG ? sys_siglist[sig] : "unknown signal"); 463 464 sleep(STALL_TIMEOUT); 465 _exit(sig); /* reboot */ 466 } 467 468 /* 469 * Get the security level of the kernel. 470 */ 471 int 472 getsecuritylevel() 473 { 474 #ifdef KERN_SECURELVL 475 int name[2], curlevel; 476 size_t len; 477 extern int errno; 478 479 name[0] = CTL_KERN; 480 name[1] = KERN_SECURELVL; 481 len = sizeof curlevel; 482 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 483 emergency("cannot get kernel security level: %s", 484 strerror(errno)); 485 return (-1); 486 } 487 return (curlevel); 488 #else 489 return (-1); 490 #endif 491 } 492 493 /* 494 * Set the security level of the kernel. 495 */ 496 void 497 setsecuritylevel(newlevel) 498 int newlevel; 499 { 500 #ifdef KERN_SECURELVL 501 int name[2], curlevel; 502 extern int errno; 503 504 curlevel = getsecuritylevel(); 505 if (newlevel == curlevel) 506 return; 507 name[0] = CTL_KERN; 508 name[1] = KERN_SECURELVL; 509 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 510 emergency( 511 "cannot change kernel security level from %d to %d: %s", 512 curlevel, newlevel, strerror(errno)); 513 return; 514 } 515 #ifdef SECURE 516 warning("kernel security level changed from %d to %d", 517 curlevel, newlevel); 518 #endif 519 #endif 520 } 521 522 /* 523 * Change states in the finite state machine. 524 * The initial state is passed as an argument. 525 */ 526 void 527 transition(s) 528 state_t s; 529 { 530 for (;;) 531 s = (state_t) (*s)(); 532 } 533 534 /* 535 * Close out the accounting files for a login session. 536 * NB: should send a message to the session logger to avoid blocking. 537 */ 538 void 539 clear_session_logs(sp) 540 session_t *sp; 541 { 542 char *line = sp->se_device + sizeof(_PATH_DEV) - 1; 543 544 if (logout(line)) 545 logwtmp(line, "", ""); 546 } 547 548 /* 549 * Start a session and allocate a controlling terminal. 550 * Only called by children of init after forking. 551 */ 552 void 553 setctty(name) 554 char *name; 555 { 556 int fd; 557 558 (void) revoke(name); 559 if ((fd = open(name, O_RDWR)) == -1) { 560 stall("can't open %s: %m", name); 561 _exit(1); 562 } 563 if (login_tty(fd) == -1) { 564 stall("can't get %s for controlling terminal: %m", name); 565 _exit(1); 566 } 567 } 568 569 /* 570 * Bring the system up single user. 571 */ 572 state_func_t 573 single_user() 574 { 575 pid_t pid, wpid; 576 int status; 577 sigset_t mask; 578 char *shell = _PATH_BSHELL; 579 char *argv[2]; 580 #ifdef SECURE 581 struct ttyent *typ; 582 struct passwd *pp; 583 static const char banner[] = 584 "Enter root password, or ^D to go multi-user\n"; 585 char *clear, *password; 586 #endif 587 588 /* 589 * If the kernel is in secure mode, downgrade it to insecure mode. 590 */ 591 if (getsecuritylevel() > 0) 592 setsecuritylevel(0); 593 594 if (Reboot) { 595 /* Instead of going single user, let's halt the machine */ 596 sync(); 597 alarm(2); 598 pause(); 599 reboot(RB_AUTOBOOT); 600 _exit(0); 601 } 602 603 if ((pid = fork()) == 0) { 604 /* 605 * Start the single user session. 606 */ 607 setctty(_PATH_CONSOLE); 608 609 #ifdef SECURE 610 /* 611 * Check the root password. 612 * We don't care if the console is 'on' by default; 613 * it's the only tty that can be 'off' and 'secure'. 614 */ 615 typ = getttynam("console"); 616 pp = getpwnam("root"); 617 if (typ && (typ->ty_status & TTY_SECURE) == 0 && pp && *pp->pw_passwd) { 618 write(2, banner, sizeof banner - 1); 619 for (;;) { 620 clear = getpass("Password:"); 621 if (clear == 0 || *clear == '\0') 622 _exit(0); 623 password = crypt(clear, pp->pw_passwd); 624 bzero(clear, _PASSWORD_LEN); 625 if (strcmp(password, pp->pw_passwd) == 0) 626 break; 627 warning("single-user login failed\n"); 628 } 629 } 630 endttyent(); 631 endpwent(); 632 #endif /* SECURE */ 633 634 #ifdef DEBUGSHELL 635 { 636 char altshell[128], *cp = altshell; 637 int num; 638 639 #define SHREQUEST \ 640 "Enter pathname of shell or RETURN for sh: " 641 (void)write(STDERR_FILENO, 642 SHREQUEST, sizeof(SHREQUEST) - 1); 643 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 644 num != 0 && *cp != '\n' && cp < &altshell[127]) 645 cp++; 646 *cp = '\0'; 647 if (altshell[0] != '\0') 648 shell = altshell; 649 } 650 #endif /* DEBUGSHELL */ 651 652 /* 653 * Unblock signals. 654 * We catch all the interesting ones, 655 * and those are reset to SIG_DFL on exec. 656 */ 657 sigemptyset(&mask); 658 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 659 660 /* 661 * Fire off a shell. 662 * If the default one doesn't work, try the Bourne shell. 663 */ 664 argv[0] = "-sh"; 665 argv[1] = 0; 666 execv(shell, argv); 667 emergency("can't exec %s for single user: %m", shell); 668 execv(_PATH_BSHELL, argv); 669 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 670 sleep(STALL_TIMEOUT); 671 _exit(1); 672 } 673 674 if (pid == -1) { 675 /* 676 * We are seriously hosed. Do our best. 677 */ 678 emergency("can't fork single-user shell, trying again"); 679 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 680 continue; 681 return (state_func_t) single_user; 682 } 683 684 requested_transition = 0; 685 do { 686 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 687 collect_child(wpid); 688 if (wpid == -1) { 689 if (errno == EINTR) 690 continue; 691 warning("wait for single-user shell failed: %m; restarting"); 692 return (state_func_t) single_user; 693 } 694 if (wpid == pid && WIFSTOPPED(status)) { 695 warning("init: shell stopped, restarting\n"); 696 kill(pid, SIGCONT); 697 wpid = -1; 698 } 699 } while (wpid != pid && !requested_transition); 700 701 if (requested_transition) 702 return (state_func_t) requested_transition; 703 704 if (!WIFEXITED(status)) { 705 if (WTERMSIG(status) == SIGKILL) { 706 /* 707 * reboot(8) killed shell? 708 */ 709 warning("single user shell terminated."); 710 sleep(STALL_TIMEOUT); 711 _exit(0); 712 } else { 713 warning("single user shell terminated, restarting"); 714 return (state_func_t) single_user; 715 } 716 } 717 718 runcom_mode = FASTBOOT; 719 return (state_func_t) runcom; 720 } 721 722 /* 723 * Run the system startup script. 724 */ 725 state_func_t 726 runcom() 727 { 728 pid_t pid, wpid; 729 int status; 730 char *argv[4]; 731 struct sigaction sa; 732 733 if ((pid = fork()) == 0) { 734 sigemptyset(&sa.sa_mask); 735 sa.sa_flags = 0; 736 sa.sa_handler = SIG_IGN; 737 (void) sigaction(SIGTSTP, &sa, (struct sigaction *)0); 738 (void) sigaction(SIGHUP, &sa, (struct sigaction *)0); 739 740 setctty(_PATH_CONSOLE); 741 742 argv[0] = "sh"; 743 argv[1] = _PATH_RUNCOM; 744 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0; 745 argv[3] = 0; 746 747 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 748 749 #ifdef LOGIN_CAP 750 setprocresources(RESOURCE_RC); 751 #endif 752 execv(_PATH_BSHELL, argv); 753 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM); 754 _exit(1); /* force single user mode */ 755 } 756 757 if (pid == -1) { 758 emergency("can't fork for %s on %s: %m", 759 _PATH_BSHELL, _PATH_RUNCOM); 760 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 761 continue; 762 sleep(STALL_TIMEOUT); 763 return (state_func_t) single_user; 764 } 765 766 /* 767 * Copied from single_user(). This is a bit paranoid. 768 */ 769 do { 770 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 771 collect_child(wpid); 772 if (wpid == -1) { 773 if (errno == EINTR) 774 continue; 775 warning("wait for %s on %s failed: %m; going to single user mode", 776 _PATH_BSHELL, _PATH_RUNCOM); 777 return (state_func_t) single_user; 778 } 779 if (wpid == pid && WIFSTOPPED(status)) { 780 warning("init: %s on %s stopped, restarting\n", 781 _PATH_BSHELL, _PATH_RUNCOM); 782 kill(pid, SIGCONT); 783 wpid = -1; 784 } 785 } while (wpid != pid); 786 787 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 788 requested_transition == catatonia) { 789 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 790 sigset_t s; 791 792 sigfillset(&s); 793 for (;;) 794 sigsuspend(&s); 795 } 796 797 if (!WIFEXITED(status)) { 798 warning("%s on %s terminated abnormally, going to single user mode", 799 _PATH_BSHELL, _PATH_RUNCOM); 800 return (state_func_t) single_user; 801 } 802 803 if (WEXITSTATUS(status)) 804 return (state_func_t) single_user; 805 806 runcom_mode = AUTOBOOT; /* the default */ 807 /* NB: should send a message to the session logger to avoid blocking. */ 808 logwtmp("~", "reboot", ""); 809 return (state_func_t) read_ttys; 810 } 811 812 /* 813 * Open the session database. 814 * 815 * NB: We could pass in the size here; is it necessary? 816 */ 817 int 818 start_session_db() 819 { 820 if (session_db && (*session_db->close)(session_db)) 821 emergency("session database close: %s", strerror(errno)); 822 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 823 emergency("session database open: %s", strerror(errno)); 824 return (1); 825 } 826 return (0); 827 828 } 829 830 /* 831 * Add a new login session. 832 */ 833 void 834 add_session(sp) 835 session_t *sp; 836 { 837 DBT key; 838 DBT data; 839 840 key.data = &sp->se_process; 841 key.size = sizeof sp->se_process; 842 data.data = &sp; 843 data.size = sizeof sp; 844 845 if ((*session_db->put)(session_db, &key, &data, 0)) 846 emergency("insert %d: %s", sp->se_process, strerror(errno)); 847 } 848 849 /* 850 * Delete an old login session. 851 */ 852 void 853 del_session(sp) 854 session_t *sp; 855 { 856 DBT key; 857 858 key.data = &sp->se_process; 859 key.size = sizeof sp->se_process; 860 861 if ((*session_db->del)(session_db, &key, 0)) 862 emergency("delete %d: %s", sp->se_process, strerror(errno)); 863 } 864 865 /* 866 * Look up a login session by pid. 867 */ 868 session_t * 869 #ifdef __STDC__ 870 find_session(pid_t pid) 871 #else 872 find_session(pid) 873 pid_t pid; 874 #endif 875 { 876 DBT key; 877 DBT data; 878 session_t *ret; 879 880 key.data = &pid; 881 key.size = sizeof pid; 882 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 883 return 0; 884 bcopy(data.data, (char *)&ret, sizeof(ret)); 885 return ret; 886 } 887 888 /* 889 * Construct an argument vector from a command line. 890 */ 891 char ** 892 construct_argv(command) 893 char *command; 894 { 895 char *strk (char *); 896 register int argc = 0; 897 register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 898 * sizeof (char *)); 899 900 if ((argv[argc++] = strk(command)) == 0) 901 return 0; 902 while (argv[argc++] = strk((char *) 0)) 903 continue; 904 return argv; 905 } 906 907 /* 908 * Deallocate a session descriptor. 909 */ 910 void 911 free_session(sp) 912 register session_t *sp; 913 { 914 free(sp->se_device); 915 if (sp->se_getty) { 916 free(sp->se_getty); 917 free(sp->se_getty_argv_space); 918 free(sp->se_getty_argv); 919 } 920 if (sp->se_window) { 921 free(sp->se_window); 922 free(sp->se_window_argv_space); 923 free(sp->se_window_argv); 924 } 925 if (sp->se_type) 926 free(sp->se_type); 927 free(sp); 928 } 929 930 /* 931 * Allocate a new session descriptor. 932 */ 933 session_t * 934 new_session(sprev, session_index, typ) 935 session_t *sprev; 936 int session_index; 937 register struct ttyent *typ; 938 { 939 register session_t *sp; 940 941 if ((typ->ty_status & TTY_ON) == 0 || 942 typ->ty_name == 0 || 943 typ->ty_getty == 0) 944 return 0; 945 946 sp = (session_t *) malloc(sizeof (session_t)); 947 bzero(sp, sizeof *sp); 948 949 sp->se_index = session_index; 950 951 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 952 (void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 953 954 if (setupargv(sp, typ) == 0) { 955 free_session(sp); 956 return (0); 957 } 958 959 sp->se_next = 0; 960 if (sprev == 0) { 961 sessions = sp; 962 sp->se_prev = 0; 963 } else { 964 sprev->se_next = sp; 965 sp->se_prev = sprev; 966 } 967 968 return sp; 969 } 970 971 /* 972 * Calculate getty and if useful window argv vectors. 973 */ 974 int 975 setupargv(sp, typ) 976 session_t *sp; 977 struct ttyent *typ; 978 { 979 980 if (sp->se_getty) { 981 free(sp->se_getty); 982 free(sp->se_getty_argv_space); 983 free(sp->se_getty_argv); 984 } 985 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 986 (void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 987 sp->se_getty_argv_space = strdup(sp->se_getty); 988 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 989 if (sp->se_getty_argv == 0) { 990 warning("can't parse getty for port %s", sp->se_device); 991 free(sp->se_getty); 992 free(sp->se_getty_argv_space); 993 sp->se_getty = sp->se_getty_argv_space = 0; 994 return (0); 995 } 996 if (sp->se_window) { 997 free(sp->se_window); 998 free(sp->se_window_argv_space); 999 free(sp->se_window_argv); 1000 } 1001 sp->se_window = sp->se_window_argv_space = 0; 1002 sp->se_window_argv = 0; 1003 if (typ->ty_window) { 1004 sp->se_window = strdup(typ->ty_window); 1005 sp->se_window_argv_space = strdup(sp->se_window); 1006 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1007 if (sp->se_window_argv == 0) { 1008 warning("can't parse window for port %s", 1009 sp->se_device); 1010 free(sp->se_window_argv_space); 1011 free(sp->se_window); 1012 sp->se_window = sp->se_window_argv_space = 0; 1013 return (0); 1014 } 1015 } 1016 if (sp->se_type) 1017 free(sp->se_type); 1018 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1019 return (1); 1020 } 1021 1022 /* 1023 * Walk the list of ttys and create sessions for each active line. 1024 */ 1025 state_func_t 1026 read_ttys() 1027 { 1028 int session_index = 0; 1029 register session_t *sp, *snext; 1030 register struct ttyent *typ; 1031 1032 /* 1033 * Destroy any previous session state. 1034 * There shouldn't be any, but just in case... 1035 */ 1036 for (sp = sessions; sp; sp = snext) { 1037 if (sp->se_process) 1038 clear_session_logs(sp); 1039 snext = sp->se_next; 1040 free_session(sp); 1041 } 1042 sessions = 0; 1043 if (start_session_db()) 1044 return (state_func_t) single_user; 1045 1046 /* 1047 * Allocate a session entry for each active port. 1048 * Note that sp starts at 0. 1049 */ 1050 while (typ = getttyent()) 1051 if (snext = new_session(sp, ++session_index, typ)) 1052 sp = snext; 1053 1054 endttyent(); 1055 1056 return (state_func_t) multi_user; 1057 } 1058 1059 /* 1060 * Start a window system running. 1061 */ 1062 void 1063 start_window_system(sp) 1064 session_t *sp; 1065 { 1066 pid_t pid; 1067 sigset_t mask; 1068 char term[64], *env[2]; 1069 1070 if ((pid = fork()) == -1) { 1071 emergency("can't fork for window system on port %s: %m", 1072 sp->se_device); 1073 /* hope that getty fails and we can try again */ 1074 return; 1075 } 1076 1077 if (pid) 1078 return; 1079 1080 sigemptyset(&mask); 1081 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1082 1083 if (setsid() < 0) 1084 emergency("setsid failed (window) %m"); 1085 1086 #ifdef LOGIN_CAP 1087 setprocresources(RESOURCE_WINDOW); 1088 #endif 1089 if (sp->se_type) { 1090 /* Don't use malloc after fork */ 1091 strcpy(term, "TERM="); 1092 strncat(term, sp->se_type, sizeof(term) - 6); 1093 env[0] = term; 1094 env[1] = 0; 1095 } 1096 else 1097 env[0] = 0; 1098 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1099 stall("can't exec window system '%s' for port %s: %m", 1100 sp->se_window_argv[0], sp->se_device); 1101 _exit(1); 1102 } 1103 1104 /* 1105 * Start a login session running. 1106 */ 1107 pid_t 1108 start_getty(sp) 1109 session_t *sp; 1110 { 1111 pid_t pid; 1112 sigset_t mask; 1113 time_t current_time = time((time_t *) 0); 1114 int too_quick = 0; 1115 char term[64], *env[2]; 1116 1117 if (current_time >= sp->se_started && 1118 current_time - sp->se_started < GETTY_SPACING) { 1119 if (++sp->se_nspace > GETTY_NSPACE) { 1120 sp->se_nspace = 0; 1121 too_quick = 1; 1122 } 1123 } else 1124 sp->se_nspace = 0; 1125 1126 /* 1127 * fork(), not vfork() -- we can't afford to block. 1128 */ 1129 if ((pid = fork()) == -1) { 1130 emergency("can't fork for getty on port %s: %m", sp->se_device); 1131 return -1; 1132 } 1133 1134 if (pid) 1135 return pid; 1136 1137 if (too_quick) { 1138 warning("getty repeating too quickly on port %s, sleeping %d secs", 1139 sp->se_device, GETTY_SLEEP); 1140 sleep((unsigned) GETTY_SLEEP); 1141 } 1142 1143 if (sp->se_window) { 1144 start_window_system(sp); 1145 sleep(WINDOW_WAIT); 1146 } 1147 1148 sigemptyset(&mask); 1149 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1150 1151 #ifdef LOGIN_CAP 1152 setprocresources(RESOURCE_GETTY); 1153 #endif 1154 if (sp->se_type) { 1155 /* Don't use malloc after fork */ 1156 strcpy(term, "TERM="); 1157 strncat(term, sp->se_type, sizeof(term) - 6); 1158 env[0] = term; 1159 env[1] = 0; 1160 } 1161 else 1162 env[0] = 0; 1163 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1164 stall("can't exec getty '%s' for port %s: %m", 1165 sp->se_getty_argv[0], sp->se_device); 1166 _exit(1); 1167 } 1168 1169 /* 1170 * Collect exit status for a child. 1171 * If an exiting login, start a new login running. 1172 */ 1173 void 1174 #ifdef __STDC__ 1175 collect_child(pid_t pid) 1176 #else 1177 collect_child(pid) 1178 pid_t pid; 1179 #endif 1180 { 1181 register session_t *sp, *sprev, *snext; 1182 1183 if (! sessions) 1184 return; 1185 1186 if (! (sp = find_session(pid))) 1187 return; 1188 1189 clear_session_logs(sp); 1190 del_session(sp); 1191 sp->se_process = 0; 1192 1193 if (sp->se_flags & SE_SHUTDOWN) { 1194 if (sprev = sp->se_prev) 1195 sprev->se_next = sp->se_next; 1196 else 1197 sessions = sp->se_next; 1198 if (snext = sp->se_next) 1199 snext->se_prev = sp->se_prev; 1200 free_session(sp); 1201 return; 1202 } 1203 1204 if ((pid = start_getty(sp)) == -1) { 1205 /* serious trouble */ 1206 requested_transition = clean_ttys; 1207 return; 1208 } 1209 1210 sp->se_process = pid; 1211 sp->se_started = time((time_t *) 0); 1212 add_session(sp); 1213 } 1214 1215 /* 1216 * Catch a signal and request a state transition. 1217 */ 1218 void 1219 transition_handler(sig) 1220 int sig; 1221 { 1222 1223 switch (sig) { 1224 case SIGHUP: 1225 requested_transition = clean_ttys; 1226 break; 1227 case SIGINT: 1228 Reboot = TRUE; 1229 case SIGTERM: 1230 requested_transition = death; 1231 break; 1232 case SIGTSTP: 1233 requested_transition = catatonia; 1234 break; 1235 default: 1236 requested_transition = 0; 1237 break; 1238 } 1239 } 1240 1241 /* 1242 * Take the system multiuser. 1243 */ 1244 state_func_t 1245 multi_user() 1246 { 1247 pid_t pid; 1248 register session_t *sp; 1249 1250 requested_transition = 0; 1251 1252 /* 1253 * If the administrator has not set the security level to -1 1254 * to indicate that the kernel should not run multiuser in secure 1255 * mode, and the run script has not set a higher level of security 1256 * than level 1, then put the kernel into secure mode. 1257 */ 1258 if (getsecuritylevel() == 0) 1259 setsecuritylevel(1); 1260 1261 for (sp = sessions; sp; sp = sp->se_next) { 1262 if (sp->se_process) 1263 continue; 1264 if ((pid = start_getty(sp)) == -1) { 1265 /* serious trouble */ 1266 requested_transition = clean_ttys; 1267 break; 1268 } 1269 sp->se_process = pid; 1270 sp->se_started = time((time_t *) 0); 1271 add_session(sp); 1272 } 1273 1274 while (!requested_transition) 1275 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1276 collect_child(pid); 1277 1278 return (state_func_t) requested_transition; 1279 } 1280 1281 /* 1282 * This is an n-squared algorithm. We hope it isn't run often... 1283 */ 1284 state_func_t 1285 clean_ttys() 1286 { 1287 register session_t *sp, *sprev; 1288 register struct ttyent *typ; 1289 register int session_index = 0; 1290 register int devlen; 1291 char *old_getty, *old_window, *old_type; 1292 1293 if (! sessions) 1294 return (state_func_t) multi_user; 1295 1296 devlen = sizeof(_PATH_DEV) - 1; 1297 while (typ = getttyent()) { 1298 ++session_index; 1299 1300 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1301 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1302 break; 1303 1304 if (sp) { 1305 if (sp->se_index != session_index) { 1306 warning("port %s changed utmp index from %d to %d", 1307 sp->se_device, sp->se_index, 1308 session_index); 1309 sp->se_index = session_index; 1310 } 1311 if ((typ->ty_status & TTY_ON) == 0 || 1312 typ->ty_getty == 0) { 1313 sp->se_flags |= SE_SHUTDOWN; 1314 kill(sp->se_process, SIGHUP); 1315 continue; 1316 } 1317 sp->se_flags &= ~SE_SHUTDOWN; 1318 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1319 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1320 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1321 if (setupargv(sp, typ) == 0) { 1322 warning("can't parse getty for port %s", 1323 sp->se_device); 1324 sp->se_flags |= SE_SHUTDOWN; 1325 kill(sp->se_process, SIGHUP); 1326 } 1327 else if ( !old_getty 1328 || !old_type && sp->se_type 1329 || old_type && !sp->se_type 1330 || !old_window && sp->se_window 1331 || old_window && !sp->se_window 1332 || strcmp(old_getty, sp->se_getty) != 0 1333 || old_window && strcmp(old_window, sp->se_window) != 0 1334 || old_type && strcmp(old_type, sp->se_type) != 0 1335 ) { 1336 /* Don't set SE_SHUTDOWN here */ 1337 sp->se_nspace = 0; 1338 sp->se_started = 0; 1339 kill(sp->se_process, SIGHUP); 1340 } 1341 if (old_getty) 1342 free(old_getty); 1343 if (old_getty) 1344 free(old_window); 1345 if (old_type) 1346 free(old_type); 1347 continue; 1348 } 1349 1350 new_session(sprev, session_index, typ); 1351 } 1352 1353 endttyent(); 1354 1355 return (state_func_t) multi_user; 1356 } 1357 1358 /* 1359 * Block further logins. 1360 */ 1361 state_func_t 1362 catatonia() 1363 { 1364 register session_t *sp; 1365 1366 for (sp = sessions; sp; sp = sp->se_next) 1367 sp->se_flags |= SE_SHUTDOWN; 1368 1369 return (state_func_t) multi_user; 1370 } 1371 1372 /* 1373 * Note SIGALRM. 1374 */ 1375 void 1376 alrm_handler(sig) 1377 int sig; 1378 { 1379 clang = 1; 1380 } 1381 1382 /* 1383 * Bring the system down to single user. 1384 */ 1385 state_func_t 1386 death() 1387 { 1388 register session_t *sp; 1389 register int i; 1390 pid_t pid; 1391 static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL }; 1392 1393 for (sp = sessions; sp; sp = sp->se_next) 1394 sp->se_flags |= SE_SHUTDOWN; 1395 1396 /* NB: should send a message to the session logger to avoid blocking. */ 1397 logwtmp("~", "shutdown", ""); 1398 1399 for (i = 0; i < 3; ++i) { 1400 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1401 return (state_func_t) single_user; 1402 1403 clang = 0; 1404 alarm(DEATH_WATCH); 1405 do 1406 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1407 collect_child(pid); 1408 while (clang == 0 && errno != ECHILD); 1409 1410 if (errno == ECHILD) 1411 return (state_func_t) single_user; 1412 } 1413 1414 warning("some processes would not die; ps axl advised"); 1415 1416 return (state_func_t) single_user; 1417 } 1418 char * 1419 strk (char *p) 1420 { 1421 static char *t; 1422 char *q; 1423 int c; 1424 1425 if (p) 1426 t = p; 1427 if (!t) 1428 return 0; 1429 1430 c = *t; 1431 while (c == ' ' || c == '\t' ) 1432 c = *++t; 1433 if (!c) { 1434 t = 0; 1435 return 0; 1436 } 1437 q = t; 1438 if (c == '\'') { 1439 c = *++t; 1440 q = t; 1441 while (c && c != '\'') 1442 c = *++t; 1443 if (!c) /* unterminated string */ 1444 q = t = 0; 1445 else 1446 *t++ = 0; 1447 } else { 1448 while (c && c != ' ' && c != '\t' ) 1449 c = *++t; 1450 *t++ = 0; 1451 if (!c) 1452 t = 0; 1453 } 1454 return q; 1455 } 1456 1457 #ifdef LOGIN_CAP 1458 void 1459 setprocresources(cname) 1460 const char *cname; 1461 { 1462 login_cap_t *lc; 1463 if ((lc = login_getclassbyname(cname, (char*)NULL)) != NULL) { 1464 setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES); 1465 login_close(lc); 1466 } 1467 } 1468 #endif 1469