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