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 if (devfs) { 252 mount("devfs", "/dev", MNT_NOEXEC|MNT_RDONLY, 0); 253 } 254 255 /* 256 * We catch or block signals rather than ignore them, 257 * so that they get reset on exec. 258 */ 259 handle(badsys, SIGSYS, 0); 260 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, 261 SIGBUS, SIGXCPU, SIGXFSZ, 0); 262 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, 0); 263 handle(alrm_handler, SIGALRM, 0); 264 sigfillset(&mask); 265 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 266 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM, 0); 267 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 268 sigemptyset(&sa.sa_mask); 269 sa.sa_flags = 0; 270 sa.sa_handler = SIG_IGN; 271 (void) sigaction(SIGTTIN, &sa, (struct sigaction *)0); 272 (void) sigaction(SIGTTOU, &sa, (struct sigaction *)0); 273 274 /* 275 * Paranoia. 276 */ 277 close(0); 278 close(1); 279 close(2); 280 281 /* 282 * Start the state machine. 283 */ 284 transition(requested_transition); 285 286 /* 287 * Should never reach here. 288 */ 289 return 1; 290 } 291 292 /* 293 * Associate a function with a signal handler. 294 */ 295 void 296 #ifdef __STDC__ 297 handle(sig_t handler, ...) 298 #else 299 handle(va_alist) 300 va_dcl 301 #endif 302 { 303 int sig; 304 struct sigaction sa; 305 int mask_everything; 306 va_list ap; 307 #ifndef __STDC__ 308 sig_t handler; 309 310 va_start(ap); 311 handler = va_arg(ap, sig_t); 312 #else 313 va_start(ap, handler); 314 #endif 315 316 sa.sa_handler = handler; 317 sigfillset(&mask_everything); 318 319 while (sig = va_arg(ap, int)) { 320 sa.sa_mask = mask_everything; 321 /* XXX SA_RESTART? */ 322 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 323 sigaction(sig, &sa, (struct sigaction *) 0); 324 } 325 va_end(ap); 326 } 327 328 /* 329 * Delete a set of signals from a mask. 330 */ 331 void 332 #ifdef __STDC__ 333 delset(sigset_t *maskp, ...) 334 #else 335 delset(va_alist) 336 va_dcl 337 #endif 338 { 339 int sig; 340 va_list ap; 341 #ifndef __STDC__ 342 sigset_t *maskp; 343 344 va_start(ap); 345 maskp = va_arg(ap, sigset_t *); 346 #else 347 va_start(ap, maskp); 348 #endif 349 350 while (sig = va_arg(ap, int)) 351 sigdelset(maskp, sig); 352 va_end(ap); 353 } 354 355 /* 356 * Log a message and sleep for a while (to give someone an opportunity 357 * to read it and to save log or hardcopy output if the problem is chronic). 358 * NB: should send a message to the session logger to avoid blocking. 359 */ 360 void 361 #ifdef __STDC__ 362 stall(char *message, ...) 363 #else 364 stall(va_alist) 365 va_dcl 366 #endif 367 { 368 va_list ap; 369 #ifndef __STDC__ 370 char *message; 371 372 va_start(ap); 373 message = va_arg(ap, char *); 374 #else 375 va_start(ap, message); 376 #endif 377 378 vsyslog(LOG_ALERT, message, ap); 379 va_end(ap); 380 sleep(STALL_TIMEOUT); 381 } 382 383 /* 384 * Like stall(), but doesn't sleep. 385 * If cpp had variadic macros, the two functions could be #defines for another. 386 * NB: should send a message to the session logger to avoid blocking. 387 */ 388 void 389 #ifdef __STDC__ 390 warning(char *message, ...) 391 #else 392 warning(va_alist) 393 va_dcl 394 #endif 395 { 396 va_list ap; 397 #ifndef __STDC__ 398 char *message; 399 400 va_start(ap); 401 message = va_arg(ap, char *); 402 #else 403 va_start(ap, message); 404 #endif 405 406 vsyslog(LOG_ALERT, message, ap); 407 va_end(ap); 408 } 409 410 /* 411 * Log an emergency message. 412 * NB: should send a message to the session logger to avoid blocking. 413 */ 414 void 415 #ifdef __STDC__ 416 emergency(char *message, ...) 417 #else 418 emergency(va_alist) 419 va_dcl 420 #endif 421 { 422 va_list ap; 423 #ifndef __STDC__ 424 char *message; 425 426 va_start(ap); 427 message = va_arg(ap, char *); 428 #else 429 va_start(ap, message); 430 #endif 431 432 vsyslog(LOG_EMERG, message, ap); 433 va_end(ap); 434 } 435 436 /* 437 * Catch a SIGSYS signal. 438 * 439 * These may arise if a system does not support sysctl. 440 * We tolerate up to 25 of these, then throw in the towel. 441 */ 442 void 443 badsys(sig) 444 int sig; 445 { 446 static int badcount = 0; 447 448 if (badcount++ < 25) 449 return; 450 disaster(sig); 451 } 452 453 /* 454 * Catch an unexpected signal. 455 */ 456 void 457 disaster(sig) 458 int sig; 459 { 460 emergency("fatal signal: %s", 461 sig < (unsigned) NSIG ? sys_siglist[sig] : "unknown signal"); 462 463 sleep(STALL_TIMEOUT); 464 _exit(sig); /* reboot */ 465 } 466 467 /* 468 * Get the security level of the kernel. 469 */ 470 int 471 getsecuritylevel() 472 { 473 #ifdef KERN_SECURELVL 474 int name[2], curlevel; 475 size_t len; 476 extern int errno; 477 478 name[0] = CTL_KERN; 479 name[1] = KERN_SECURELVL; 480 len = sizeof curlevel; 481 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 482 emergency("cannot get kernel security level: %s", 483 strerror(errno)); 484 return (-1); 485 } 486 return (curlevel); 487 #else 488 return (-1); 489 #endif 490 } 491 492 /* 493 * Set the security level of the kernel. 494 */ 495 void 496 setsecuritylevel(newlevel) 497 int newlevel; 498 { 499 #ifdef KERN_SECURELVL 500 int name[2], curlevel; 501 extern int errno; 502 503 curlevel = getsecuritylevel(); 504 if (newlevel == curlevel) 505 return; 506 name[0] = CTL_KERN; 507 name[1] = KERN_SECURELVL; 508 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 509 emergency( 510 "cannot change kernel security level from %d to %d: %s", 511 curlevel, newlevel, strerror(errno)); 512 return; 513 } 514 #ifdef SECURE 515 warning("kernel security level changed from %d to %d", 516 curlevel, newlevel); 517 #endif 518 #endif 519 } 520 521 /* 522 * Change states in the finite state machine. 523 * The initial state is passed as an argument. 524 */ 525 void 526 transition(s) 527 state_t s; 528 { 529 for (;;) 530 s = (state_t) (*s)(); 531 } 532 533 /* 534 * Close out the accounting files for a login session. 535 * NB: should send a message to the session logger to avoid blocking. 536 */ 537 void 538 clear_session_logs(sp) 539 session_t *sp; 540 { 541 char *line = sp->se_device + sizeof(_PATH_DEV) - 1; 542 543 if (logout(line)) 544 logwtmp(line, "", ""); 545 } 546 547 /* 548 * Start a session and allocate a controlling terminal. 549 * Only called by children of init after forking. 550 */ 551 void 552 setctty(name) 553 char *name; 554 { 555 int fd; 556 557 (void) revoke(name); 558 if ((fd = open(name, O_RDWR)) == -1) { 559 stall("can't open %s: %m", name); 560 _exit(1); 561 } 562 if (login_tty(fd) == -1) { 563 stall("can't get %s for controlling terminal: %m", name); 564 _exit(1); 565 } 566 } 567 568 /* 569 * Bring the system up single user. 570 */ 571 state_func_t 572 single_user() 573 { 574 pid_t pid, wpid; 575 int status; 576 sigset_t mask; 577 char *shell = _PATH_BSHELL; 578 char *argv[2]; 579 #ifdef SECURE 580 struct ttyent *typ; 581 struct passwd *pp; 582 static const char banner[] = 583 "Enter root password, or ^D to go multi-user\n"; 584 char *clear, *password; 585 #endif 586 587 /* 588 * If the kernel is in secure mode, downgrade it to insecure mode. 589 */ 590 if (getsecuritylevel() > 0) 591 setsecuritylevel(0); 592 593 if (Reboot) { 594 /* Instead of going single user, let's halt the machine */ 595 sync(); 596 alarm(2); 597 pause(); 598 reboot(RB_AUTOBOOT); 599 _exit(0); 600 } 601 602 if ((pid = fork()) == 0) { 603 /* 604 * Start the single user session. 605 */ 606 setctty(_PATH_CONSOLE); 607 608 #ifdef SECURE 609 /* 610 * Check the root password. 611 * We don't care if the console is 'on' by default; 612 * it's the only tty that can be 'off' and 'secure'. 613 */ 614 typ = getttynam("console"); 615 pp = getpwnam("root"); 616 if (typ && (typ->ty_status & TTY_SECURE) == 0 && pp && *pp->pw_passwd) { 617 write(2, banner, sizeof banner - 1); 618 for (;;) { 619 clear = getpass("Password:"); 620 if (clear == 0 || *clear == '\0') 621 _exit(0); 622 password = crypt(clear, pp->pw_passwd); 623 bzero(clear, _PASSWORD_LEN); 624 if (strcmp(password, pp->pw_passwd) == 0) 625 break; 626 warning("single-user login failed\n"); 627 } 628 } 629 endttyent(); 630 endpwent(); 631 #endif /* SECURE */ 632 633 #ifdef DEBUGSHELL 634 { 635 char altshell[128], *cp = altshell; 636 int num; 637 638 #define SHREQUEST \ 639 "Enter pathname of shell or RETURN for sh: " 640 (void)write(STDERR_FILENO, 641 SHREQUEST, sizeof(SHREQUEST) - 1); 642 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 643 num != 0 && *cp != '\n' && cp < &altshell[127]) 644 cp++; 645 *cp = '\0'; 646 if (altshell[0] != '\0') 647 shell = altshell; 648 } 649 #endif /* DEBUGSHELL */ 650 651 /* 652 * Unblock signals. 653 * We catch all the interesting ones, 654 * and those are reset to SIG_DFL on exec. 655 */ 656 sigemptyset(&mask); 657 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 658 659 /* 660 * Fire off a shell. 661 * If the default one doesn't work, try the Bourne shell. 662 */ 663 argv[0] = "-sh"; 664 argv[1] = 0; 665 execv(shell, argv); 666 emergency("can't exec %s for single user: %m", shell); 667 execv(_PATH_BSHELL, argv); 668 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 669 sleep(STALL_TIMEOUT); 670 _exit(1); 671 } 672 673 if (pid == -1) { 674 /* 675 * We are seriously hosed. Do our best. 676 */ 677 emergency("can't fork single-user shell, trying again"); 678 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 679 continue; 680 return (state_func_t) single_user; 681 } 682 683 requested_transition = 0; 684 do { 685 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 686 collect_child(wpid); 687 if (wpid == -1) { 688 if (errno == EINTR) 689 continue; 690 warning("wait for single-user shell failed: %m; restarting"); 691 return (state_func_t) single_user; 692 } 693 if (wpid == pid && WIFSTOPPED(status)) { 694 warning("init: shell stopped, restarting\n"); 695 kill(pid, SIGCONT); 696 wpid = -1; 697 } 698 } while (wpid != pid && !requested_transition); 699 700 if (requested_transition) 701 return (state_func_t) requested_transition; 702 703 if (!WIFEXITED(status)) { 704 if (WTERMSIG(status) == SIGKILL) { 705 /* 706 * reboot(8) killed shell? 707 */ 708 warning("single user shell terminated."); 709 sleep(STALL_TIMEOUT); 710 _exit(0); 711 } else { 712 warning("single user shell terminated, restarting"); 713 return (state_func_t) single_user; 714 } 715 } 716 717 runcom_mode = FASTBOOT; 718 return (state_func_t) runcom; 719 } 720 721 /* 722 * Run the system startup script. 723 */ 724 state_func_t 725 runcom() 726 { 727 pid_t pid, wpid; 728 int status; 729 char *argv[4]; 730 struct sigaction sa; 731 732 if ((pid = fork()) == 0) { 733 sigemptyset(&sa.sa_mask); 734 sa.sa_flags = 0; 735 sa.sa_handler = SIG_IGN; 736 (void) sigaction(SIGTSTP, &sa, (struct sigaction *)0); 737 (void) sigaction(SIGHUP, &sa, (struct sigaction *)0); 738 739 setctty(_PATH_CONSOLE); 740 741 argv[0] = "sh"; 742 argv[1] = _PATH_RUNCOM; 743 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0; 744 argv[3] = 0; 745 746 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 747 748 #ifdef LOGIN_CAP 749 setprocresources(RESOURCE_RC); 750 #endif 751 execv(_PATH_BSHELL, argv); 752 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM); 753 _exit(1); /* force single user mode */ 754 } 755 756 if (pid == -1) { 757 emergency("can't fork for %s on %s: %m", 758 _PATH_BSHELL, _PATH_RUNCOM); 759 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 760 continue; 761 sleep(STALL_TIMEOUT); 762 return (state_func_t) single_user; 763 } 764 765 /* 766 * Copied from single_user(). This is a bit paranoid. 767 */ 768 do { 769 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 770 collect_child(wpid); 771 if (wpid == -1) { 772 if (errno == EINTR) 773 continue; 774 warning("wait for %s on %s failed: %m; going to single user mode", 775 _PATH_BSHELL, _PATH_RUNCOM); 776 return (state_func_t) single_user; 777 } 778 if (wpid == pid && WIFSTOPPED(status)) { 779 warning("init: %s on %s stopped, restarting\n", 780 _PATH_BSHELL, _PATH_RUNCOM); 781 kill(pid, SIGCONT); 782 wpid = -1; 783 } 784 } while (wpid != pid); 785 786 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 787 requested_transition == catatonia) { 788 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 789 sigset_t s; 790 791 sigfillset(&s); 792 for (;;) 793 sigsuspend(&s); 794 } 795 796 if (!WIFEXITED(status)) { 797 warning("%s on %s terminated abnormally, going to single user mode", 798 _PATH_BSHELL, _PATH_RUNCOM); 799 return (state_func_t) single_user; 800 } 801 802 if (WEXITSTATUS(status)) 803 return (state_func_t) single_user; 804 805 runcom_mode = AUTOBOOT; /* the default */ 806 /* NB: should send a message to the session logger to avoid blocking. */ 807 logwtmp("~", "reboot", ""); 808 return (state_func_t) read_ttys; 809 } 810 811 /* 812 * Open the session database. 813 * 814 * NB: We could pass in the size here; is it necessary? 815 */ 816 int 817 start_session_db() 818 { 819 if (session_db && (*session_db->close)(session_db)) 820 emergency("session database close: %s", strerror(errno)); 821 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 822 emergency("session database open: %s", strerror(errno)); 823 return (1); 824 } 825 return (0); 826 827 } 828 829 /* 830 * Add a new login session. 831 */ 832 void 833 add_session(sp) 834 session_t *sp; 835 { 836 DBT key; 837 DBT data; 838 839 key.data = &sp->se_process; 840 key.size = sizeof sp->se_process; 841 data.data = &sp; 842 data.size = sizeof sp; 843 844 if ((*session_db->put)(session_db, &key, &data, 0)) 845 emergency("insert %d: %s", sp->se_process, strerror(errno)); 846 } 847 848 /* 849 * Delete an old login session. 850 */ 851 void 852 del_session(sp) 853 session_t *sp; 854 { 855 DBT key; 856 857 key.data = &sp->se_process; 858 key.size = sizeof sp->se_process; 859 860 if ((*session_db->del)(session_db, &key, 0)) 861 emergency("delete %d: %s", sp->se_process, strerror(errno)); 862 } 863 864 /* 865 * Look up a login session by pid. 866 */ 867 session_t * 868 #ifdef __STDC__ 869 find_session(pid_t pid) 870 #else 871 find_session(pid) 872 pid_t pid; 873 #endif 874 { 875 DBT key; 876 DBT data; 877 session_t *ret; 878 879 key.data = &pid; 880 key.size = sizeof pid; 881 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 882 return 0; 883 bcopy(data.data, (char *)&ret, sizeof(ret)); 884 return ret; 885 } 886 887 /* 888 * Construct an argument vector from a command line. 889 */ 890 char ** 891 construct_argv(command) 892 char *command; 893 { 894 char *strk (char *); 895 register int argc = 0; 896 register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 897 * sizeof (char *)); 898 899 if ((argv[argc++] = strk(command)) == 0) 900 return 0; 901 while (argv[argc++] = strk((char *) 0)) 902 continue; 903 return argv; 904 } 905 906 /* 907 * Deallocate a session descriptor. 908 */ 909 void 910 free_session(sp) 911 register session_t *sp; 912 { 913 free(sp->se_device); 914 if (sp->se_getty) { 915 free(sp->se_getty); 916 free(sp->se_getty_argv_space); 917 free(sp->se_getty_argv); 918 } 919 if (sp->se_window) { 920 free(sp->se_window); 921 free(sp->se_window_argv_space); 922 free(sp->se_window_argv); 923 } 924 if (sp->se_type) 925 free(sp->se_type); 926 free(sp); 927 } 928 929 /* 930 * Allocate a new session descriptor. 931 */ 932 session_t * 933 new_session(sprev, session_index, typ) 934 session_t *sprev; 935 int session_index; 936 register struct ttyent *typ; 937 { 938 register session_t *sp; 939 940 if ((typ->ty_status & TTY_ON) == 0 || 941 typ->ty_name == 0 || 942 typ->ty_getty == 0) 943 return 0; 944 945 sp = (session_t *) malloc(sizeof (session_t)); 946 bzero(sp, sizeof *sp); 947 948 sp->se_index = session_index; 949 950 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 951 (void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 952 953 if (setupargv(sp, typ) == 0) { 954 free_session(sp); 955 return (0); 956 } 957 958 sp->se_next = 0; 959 if (sprev == 0) { 960 sessions = sp; 961 sp->se_prev = 0; 962 } else { 963 sprev->se_next = sp; 964 sp->se_prev = sprev; 965 } 966 967 return sp; 968 } 969 970 /* 971 * Calculate getty and if useful window argv vectors. 972 */ 973 int 974 setupargv(sp, typ) 975 session_t *sp; 976 struct ttyent *typ; 977 { 978 979 if (sp->se_getty) { 980 free(sp->se_getty); 981 free(sp->se_getty_argv_space); 982 free(sp->se_getty_argv); 983 } 984 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 985 (void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 986 sp->se_getty_argv_space = strdup(sp->se_getty); 987 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 988 if (sp->se_getty_argv == 0) { 989 warning("can't parse getty for port %s", sp->se_device); 990 free(sp->se_getty); 991 free(sp->se_getty_argv_space); 992 sp->se_getty = sp->se_getty_argv_space = 0; 993 return (0); 994 } 995 if (sp->se_window) { 996 free(sp->se_window); 997 free(sp->se_window_argv_space); 998 free(sp->se_window_argv); 999 } 1000 sp->se_window = sp->se_window_argv_space = 0; 1001 sp->se_window_argv = 0; 1002 if (typ->ty_window) { 1003 sp->se_window = strdup(typ->ty_window); 1004 sp->se_window_argv_space = strdup(sp->se_window); 1005 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1006 if (sp->se_window_argv == 0) { 1007 warning("can't parse window for port %s", 1008 sp->se_device); 1009 free(sp->se_window_argv_space); 1010 free(sp->se_window); 1011 sp->se_window = sp->se_window_argv_space = 0; 1012 return (0); 1013 } 1014 } 1015 if (sp->se_type) 1016 free(sp->se_type); 1017 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1018 return (1); 1019 } 1020 1021 /* 1022 * Walk the list of ttys and create sessions for each active line. 1023 */ 1024 state_func_t 1025 read_ttys() 1026 { 1027 int session_index = 0; 1028 register session_t *sp, *snext; 1029 register struct ttyent *typ; 1030 1031 /* 1032 * Destroy any previous session state. 1033 * There shouldn't be any, but just in case... 1034 */ 1035 for (sp = sessions; sp; sp = snext) { 1036 if (sp->se_process) 1037 clear_session_logs(sp); 1038 snext = sp->se_next; 1039 free_session(sp); 1040 } 1041 sessions = 0; 1042 if (start_session_db()) 1043 return (state_func_t) single_user; 1044 1045 /* 1046 * Allocate a session entry for each active port. 1047 * Note that sp starts at 0. 1048 */ 1049 while (typ = getttyent()) 1050 if (snext = new_session(sp, ++session_index, typ)) 1051 sp = snext; 1052 1053 endttyent(); 1054 1055 return (state_func_t) multi_user; 1056 } 1057 1058 /* 1059 * Start a window system running. 1060 */ 1061 void 1062 start_window_system(sp) 1063 session_t *sp; 1064 { 1065 pid_t pid; 1066 sigset_t mask; 1067 char term[64], *env[2]; 1068 1069 if ((pid = fork()) == -1) { 1070 emergency("can't fork for window system on port %s: %m", 1071 sp->se_device); 1072 /* hope that getty fails and we can try again */ 1073 return; 1074 } 1075 1076 if (pid) 1077 return; 1078 1079 sigemptyset(&mask); 1080 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1081 1082 if (setsid() < 0) 1083 emergency("setsid failed (window) %m"); 1084 1085 #ifdef LOGIN_CAP 1086 setprocresources(RESOURCE_WINDOW); 1087 #endif 1088 if (sp->se_type) { 1089 /* Don't use malloc after fork */ 1090 strcpy(term, "TERM="); 1091 strncat(term, sp->se_type, sizeof(term) - 6); 1092 env[0] = term; 1093 env[1] = 0; 1094 } 1095 else 1096 env[0] = 0; 1097 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1098 stall("can't exec window system '%s' for port %s: %m", 1099 sp->se_window_argv[0], sp->se_device); 1100 _exit(1); 1101 } 1102 1103 /* 1104 * Start a login session running. 1105 */ 1106 pid_t 1107 start_getty(sp) 1108 session_t *sp; 1109 { 1110 pid_t pid; 1111 sigset_t mask; 1112 time_t current_time = time((time_t *) 0); 1113 int too_quick = 0; 1114 char term[64], *env[2]; 1115 1116 if (current_time >= sp->se_started && 1117 current_time - sp->se_started < GETTY_SPACING) { 1118 if (++sp->se_nspace > GETTY_NSPACE) { 1119 sp->se_nspace = 0; 1120 too_quick = 1; 1121 } 1122 } else 1123 sp->se_nspace = 0; 1124 1125 /* 1126 * fork(), not vfork() -- we can't afford to block. 1127 */ 1128 if ((pid = fork()) == -1) { 1129 emergency("can't fork for getty on port %s: %m", sp->se_device); 1130 return -1; 1131 } 1132 1133 if (pid) 1134 return pid; 1135 1136 if (too_quick) { 1137 warning("getty repeating too quickly on port %s, sleeping %d secs", 1138 sp->se_device, GETTY_SLEEP); 1139 sleep((unsigned) GETTY_SLEEP); 1140 } 1141 1142 if (sp->se_window) { 1143 start_window_system(sp); 1144 sleep(WINDOW_WAIT); 1145 } 1146 1147 sigemptyset(&mask); 1148 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1149 1150 #ifdef LOGIN_CAP 1151 setprocresources(RESOURCE_GETTY); 1152 #endif 1153 if (sp->se_type) { 1154 /* Don't use malloc after fork */ 1155 strcpy(term, "TERM="); 1156 strncat(term, sp->se_type, sizeof(term) - 6); 1157 env[0] = term; 1158 env[1] = 0; 1159 } 1160 else 1161 env[0] = 0; 1162 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1163 stall("can't exec getty '%s' for port %s: %m", 1164 sp->se_getty_argv[0], sp->se_device); 1165 _exit(1); 1166 } 1167 1168 /* 1169 * Collect exit status for a child. 1170 * If an exiting login, start a new login running. 1171 */ 1172 void 1173 #ifdef __STDC__ 1174 collect_child(pid_t pid) 1175 #else 1176 collect_child(pid) 1177 pid_t pid; 1178 #endif 1179 { 1180 register session_t *sp, *sprev, *snext; 1181 1182 if (! sessions) 1183 return; 1184 1185 if (! (sp = find_session(pid))) 1186 return; 1187 1188 clear_session_logs(sp); 1189 del_session(sp); 1190 sp->se_process = 0; 1191 1192 if (sp->se_flags & SE_SHUTDOWN) { 1193 if (sprev = sp->se_prev) 1194 sprev->se_next = sp->se_next; 1195 else 1196 sessions = sp->se_next; 1197 if (snext = sp->se_next) 1198 snext->se_prev = sp->se_prev; 1199 free_session(sp); 1200 return; 1201 } 1202 1203 if ((pid = start_getty(sp)) == -1) { 1204 /* serious trouble */ 1205 requested_transition = clean_ttys; 1206 return; 1207 } 1208 1209 sp->se_process = pid; 1210 sp->se_started = time((time_t *) 0); 1211 add_session(sp); 1212 } 1213 1214 /* 1215 * Catch a signal and request a state transition. 1216 */ 1217 void 1218 transition_handler(sig) 1219 int sig; 1220 { 1221 1222 switch (sig) { 1223 case SIGHUP: 1224 requested_transition = clean_ttys; 1225 break; 1226 case SIGINT: 1227 Reboot = TRUE; 1228 case SIGTERM: 1229 requested_transition = death; 1230 break; 1231 case SIGTSTP: 1232 requested_transition = catatonia; 1233 break; 1234 default: 1235 requested_transition = 0; 1236 break; 1237 } 1238 } 1239 1240 /* 1241 * Take the system multiuser. 1242 */ 1243 state_func_t 1244 multi_user() 1245 { 1246 pid_t pid; 1247 register session_t *sp; 1248 1249 requested_transition = 0; 1250 1251 /* 1252 * If the administrator has not set the security level to -1 1253 * to indicate that the kernel should not run multiuser in secure 1254 * mode, and the run script has not set a higher level of security 1255 * than level 1, then put the kernel into secure mode. 1256 */ 1257 if (getsecuritylevel() == 0) 1258 setsecuritylevel(1); 1259 1260 for (sp = sessions; sp; sp = sp->se_next) { 1261 if (sp->se_process) 1262 continue; 1263 if ((pid = start_getty(sp)) == -1) { 1264 /* serious trouble */ 1265 requested_transition = clean_ttys; 1266 break; 1267 } 1268 sp->se_process = pid; 1269 sp->se_started = time((time_t *) 0); 1270 add_session(sp); 1271 } 1272 1273 while (!requested_transition) 1274 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1275 collect_child(pid); 1276 1277 return (state_func_t) requested_transition; 1278 } 1279 1280 /* 1281 * This is an n-squared algorithm. We hope it isn't run often... 1282 */ 1283 state_func_t 1284 clean_ttys() 1285 { 1286 register session_t *sp, *sprev; 1287 register struct ttyent *typ; 1288 register int session_index = 0; 1289 register int devlen; 1290 char *old_getty, *old_window, *old_type; 1291 1292 if (! sessions) 1293 return (state_func_t) multi_user; 1294 1295 devlen = sizeof(_PATH_DEV) - 1; 1296 while (typ = getttyent()) { 1297 ++session_index; 1298 1299 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1300 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1301 break; 1302 1303 if (sp) { 1304 if (sp->se_index != session_index) { 1305 warning("port %s changed utmp index from %d to %d", 1306 sp->se_device, sp->se_index, 1307 session_index); 1308 sp->se_index = session_index; 1309 } 1310 if ((typ->ty_status & TTY_ON) == 0 || 1311 typ->ty_getty == 0) { 1312 sp->se_flags |= SE_SHUTDOWN; 1313 kill(sp->se_process, SIGHUP); 1314 continue; 1315 } 1316 sp->se_flags &= ~SE_SHUTDOWN; 1317 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1318 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1319 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1320 if (setupargv(sp, typ) == 0) { 1321 warning("can't parse getty for port %s", 1322 sp->se_device); 1323 sp->se_flags |= SE_SHUTDOWN; 1324 kill(sp->se_process, SIGHUP); 1325 } 1326 else if ( !old_getty 1327 || !old_type && sp->se_type 1328 || old_type && !sp->se_type 1329 || !old_window && sp->se_window 1330 || old_window && !sp->se_window 1331 || strcmp(old_getty, sp->se_getty) != 0 1332 || old_window && strcmp(old_window, sp->se_window) != 0 1333 || old_type && strcmp(old_type, sp->se_type) != 0 1334 ) { 1335 /* Don't set SE_SHUTDOWN here */ 1336 sp->se_nspace = 0; 1337 sp->se_started = 0; 1338 kill(sp->se_process, SIGHUP); 1339 } 1340 if (old_getty) 1341 free(old_getty); 1342 if (old_getty) 1343 free(old_window); 1344 if (old_type) 1345 free(old_type); 1346 continue; 1347 } 1348 1349 new_session(sprev, session_index, typ); 1350 } 1351 1352 endttyent(); 1353 1354 return (state_func_t) multi_user; 1355 } 1356 1357 /* 1358 * Block further logins. 1359 */ 1360 state_func_t 1361 catatonia() 1362 { 1363 register session_t *sp; 1364 1365 for (sp = sessions; sp; sp = sp->se_next) 1366 sp->se_flags |= SE_SHUTDOWN; 1367 1368 return (state_func_t) multi_user; 1369 } 1370 1371 /* 1372 * Note SIGALRM. 1373 */ 1374 void 1375 alrm_handler(sig) 1376 int sig; 1377 { 1378 clang = 1; 1379 } 1380 1381 /* 1382 * Bring the system down to single user. 1383 */ 1384 state_func_t 1385 death() 1386 { 1387 register session_t *sp; 1388 register int i; 1389 pid_t pid; 1390 static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL }; 1391 1392 for (sp = sessions; sp; sp = sp->se_next) 1393 sp->se_flags |= SE_SHUTDOWN; 1394 1395 /* NB: should send a message to the session logger to avoid blocking. */ 1396 logwtmp("~", "shutdown", ""); 1397 1398 for (i = 0; i < 3; ++i) { 1399 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1400 return (state_func_t) single_user; 1401 1402 clang = 0; 1403 alarm(DEATH_WATCH); 1404 do 1405 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1406 collect_child(pid); 1407 while (clang == 0 && errno != ECHILD); 1408 1409 if (errno == ECHILD) 1410 return (state_func_t) single_user; 1411 } 1412 1413 warning("some processes would not die; ps axl advised"); 1414 1415 return (state_func_t) single_user; 1416 } 1417 char * 1418 strk (char *p) 1419 { 1420 static char *t; 1421 char *q; 1422 int c; 1423 1424 if (p) 1425 t = p; 1426 if (!t) 1427 return 0; 1428 1429 c = *t; 1430 while (c == ' ' || c == '\t' ) 1431 c = *++t; 1432 if (!c) { 1433 t = 0; 1434 return 0; 1435 } 1436 q = t; 1437 if (c == '\'') { 1438 c = *++t; 1439 q = t; 1440 while (c && c != '\'') 1441 c = *++t; 1442 if (!c) /* unterminated string */ 1443 q = t = 0; 1444 else 1445 *t++ = 0; 1446 } else { 1447 while (c && c != ' ' && c != '\t' ) 1448 c = *++t; 1449 *t++ = 0; 1450 if (!c) 1451 t = 0; 1452 } 1453 return q; 1454 } 1455 1456 #ifdef LOGIN_CAP 1457 void 1458 setprocresources(cname) 1459 const char *cname; 1460 { 1461 login_cap_t *lc; 1462 if ((lc = login_getclassbyname(cname, (char*)NULL)) != NULL) { 1463 setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES); 1464 login_close(lc); 1465 } 1466 } 1467 #endif 1468