init.c revision 26594
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 * $Id$ 37 */ 38 39#ifndef lint 40static char copyright[] = 41"@(#) Copyright (c) 1991, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"; 43#endif /* not lint */ 44 45#ifndef lint 46static char sccsid[] = "@(#)init.c 8.1 (Berkeley) 7/15/93"; 47#endif /* not lint */ 48 49#include <sys/param.h> 50#include <sys/mount.h> 51#include <sys/sysctl.h> 52#include <sys/wait.h> 53 54#include <db.h> 55#include <errno.h> 56#include <fcntl.h> 57#include <signal.h> 58#include <stdio.h> 59#include <stdlib.h> 60#include <string.h> 61#include <syslog.h> 62#include <time.h> 63#include <ttyent.h> 64#include <unistd.h> 65#include <sys/reboot.h> 66#include <err.h> 67 68#ifdef __STDC__ 69#include <stdarg.h> 70#else 71#include <varargs.h> 72#endif 73 74#ifdef SECURE 75#include <pwd.h> 76#endif 77 78#ifdef LOGIN_CAP 79#include <login_cap.h> 80#endif 81 82#include "pathnames.h" 83 84/* 85 * Until the mythical util.h arrives... 86 */ 87extern int login_tty __P((int)); 88extern int logout __P((const char *)); 89extern void logwtmp __P((const char *, const char *, const char *)); 90 91/* 92 * Sleep times; used to prevent thrashing. 93 */ 94#define GETTY_SPACING 5 /* N secs minimum getty spacing */ 95#define GETTY_SLEEP 30 /* sleep N secs after spacing problem */ 96#define GETTY_NSPACE 3 /* max. spacing count to bring reaction */ 97#define WINDOW_WAIT 3 /* wait N secs after starting window */ 98#define STALL_TIMEOUT 30 /* wait N secs after warning */ 99#define DEATH_WATCH 10 /* wait N secs for procs to die */ 100#define RESOURCE_RC "daemon" 101#define RESOURCE_WINDOW "default" 102#define RESOURCE_GETTY "default" 103 104void handle __P((sig_t, ...)); 105void delset __P((sigset_t *, ...)); 106 107void stall __P((char *, ...)); 108void warning __P((char *, ...)); 109void emergency __P((char *, ...)); 110void disaster __P((int)); 111void badsys __P((int)); 112 113/* 114 * We really need a recursive typedef... 115 * The following at least guarantees that the return type of (*state_t)() 116 * is sufficiently wide to hold a function pointer. 117 */ 118typedef long (*state_func_t) __P((void)); 119typedef state_func_t (*state_t) __P((void)); 120 121state_func_t single_user __P((void)); 122state_func_t runcom __P((void)); 123state_func_t read_ttys __P((void)); 124state_func_t multi_user __P((void)); 125state_func_t clean_ttys __P((void)); 126state_func_t catatonia __P((void)); 127state_func_t death __P((void)); 128 129enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT; 130#define FALSE 0 131#define TRUE 1 132 133int Reboot = FALSE; 134 135int devfs; 136 137void transition __P((state_t)); 138state_t requested_transition = runcom; 139 140void setctty __P((char *)); 141 142typedef struct init_session { 143 int se_index; /* index of entry in ttys file */ 144 pid_t se_process; /* controlling process */ 145 time_t se_started; /* used to avoid thrashing */ 146 int se_flags; /* status of session */ 147#define SE_SHUTDOWN 0x1 /* session won't be restarted */ 148 int se_nspace; /* spacing count */ 149 char *se_device; /* filename of port */ 150 char *se_getty; /* what to run on that port */ 151 char *se_getty_argv_space; /* pre-parsed argument array space */ 152 char **se_getty_argv; /* pre-parsed argument array */ 153 char *se_window; /* window system (started only once) */ 154 char *se_window_argv_space; /* pre-parsed argument array space */ 155 char **se_window_argv; /* pre-parsed argument array */ 156 char *se_type; /* default terminal type */ 157 struct init_session *se_prev; 158 struct init_session *se_next; 159} session_t; 160 161void free_session __P((session_t *)); 162session_t *new_session __P((session_t *, int, struct ttyent *)); 163session_t *sessions; 164 165char **construct_argv __P((char *)); 166void start_window_system __P((session_t *)); 167void collect_child __P((pid_t)); 168pid_t start_getty __P((session_t *)); 169void transition_handler __P((int)); 170void alrm_handler __P((int)); 171void setsecuritylevel __P((int)); 172int getsecuritylevel __P((void)); 173int setupargv __P((session_t *, struct ttyent *)); 174#ifdef LOGIN_CAP 175void setprocresources __P((const char *)); 176#endif 177int clang; 178 179void clear_session_logs __P((session_t *)); 180 181int start_session_db __P((void)); 182void add_session __P((session_t *)); 183void del_session __P((session_t *)); 184session_t *find_session __P((pid_t)); 185DB *session_db; 186 187/* 188 * The mother of all processes. 189 */ 190int 191main(argc, argv) 192 int argc; 193 char **argv; 194{ 195 int c; 196 struct sigaction sa; 197 sigset_t mask; 198 199 200 /* Dispose of random users. */ 201 if (getuid() != 0) 202 errx(1, "%s", strerror(EPERM)); 203 204 /* System V users like to reexec init. */ 205 if (getpid() != 1) 206 errx(1, "already running"); 207 208 /* 209 * Note that this does NOT open a file... 210 * Does 'init' deserve its own facility number? 211 */ 212 openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH); 213 214 /* 215 * Create an initial session. 216 */ 217 if (setsid() < 0) 218 warning("initial setsid() failed: %m"); 219 220 /* 221 * Establish an initial user so that programs running 222 * single user do not freak out and die (like passwd). 223 */ 224 if (setlogin("root") < 0) 225 warning("setlogin() failed: %m"); 226 227 /* 228 * This code assumes that we always get arguments through flags, 229 * never through bits set in some random machine register. 230 */ 231 while ((c = getopt(argc, argv, "dsf")) != -1) 232 switch (c) { 233 case 'd': 234 devfs = 1; 235 break; 236 case 's': 237 requested_transition = single_user; 238 break; 239 case 'f': 240 runcom_mode = FASTBOOT; 241 break; 242 default: 243 warning("unrecognized flag '-%c'", c); 244 break; 245 } 246 247 if (optind != argc) 248 warning("ignoring excess arguments"); 249 250 if (devfs) { 251 mount("devfs", "/dev", MNT_NOEXEC|MNT_RDONLY, 0); 252 } 253 254 /* 255 * We catch or block signals rather than ignore them, 256 * so that they get reset on exec. 257 */ 258 handle(badsys, SIGSYS, 0); 259 handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV, 260 SIGBUS, SIGXCPU, SIGXFSZ, 0); 261 handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP, 0); 262 handle(alrm_handler, SIGALRM, 0); 263 sigfillset(&mask); 264 delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS, 265 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM, 0); 266 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 267 sigemptyset(&sa.sa_mask); 268 sa.sa_flags = 0; 269 sa.sa_handler = SIG_IGN; 270 (void) sigaction(SIGTTIN, &sa, (struct sigaction *)0); 271 (void) sigaction(SIGTTOU, &sa, (struct sigaction *)0); 272 273 /* 274 * Paranoia. 275 */ 276 close(0); 277 close(1); 278 close(2); 279 280 /* 281 * Start the state machine. 282 */ 283 transition(requested_transition); 284 285 /* 286 * Should never reach here. 287 */ 288 return 1; 289} 290 291/* 292 * Associate a function with a signal handler. 293 */ 294void 295#ifdef __STDC__ 296handle(sig_t handler, ...) 297#else 298handle(va_alist) 299 va_dcl 300#endif 301{ 302 int sig; 303 struct sigaction sa; 304 int mask_everything; 305 va_list ap; 306#ifndef __STDC__ 307 sig_t handler; 308 309 va_start(ap); 310 handler = va_arg(ap, sig_t); 311#else 312 va_start(ap, handler); 313#endif 314 315 sa.sa_handler = handler; 316 sigfillset(&mask_everything); 317 318 while (sig = va_arg(ap, int)) { 319 sa.sa_mask = mask_everything; 320 /* XXX SA_RESTART? */ 321 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0; 322 sigaction(sig, &sa, (struct sigaction *) 0); 323 } 324 va_end(ap); 325} 326 327/* 328 * Delete a set of signals from a mask. 329 */ 330void 331#ifdef __STDC__ 332delset(sigset_t *maskp, ...) 333#else 334delset(va_alist) 335 va_dcl 336#endif 337{ 338 int sig; 339 va_list ap; 340#ifndef __STDC__ 341 sigset_t *maskp; 342 343 va_start(ap); 344 maskp = va_arg(ap, sigset_t *); 345#else 346 va_start(ap, maskp); 347#endif 348 349 while (sig = va_arg(ap, int)) 350 sigdelset(maskp, sig); 351 va_end(ap); 352} 353 354/* 355 * Log a message and sleep for a while (to give someone an opportunity 356 * to read it and to save log or hardcopy output if the problem is chronic). 357 * NB: should send a message to the session logger to avoid blocking. 358 */ 359void 360#ifdef __STDC__ 361stall(char *message, ...) 362#else 363stall(va_alist) 364 va_dcl 365#endif 366{ 367 va_list ap; 368#ifndef __STDC__ 369 char *message; 370 371 va_start(ap); 372 message = va_arg(ap, char *); 373#else 374 va_start(ap, message); 375#endif 376 377 vsyslog(LOG_ALERT, message, ap); 378 va_end(ap); 379 sleep(STALL_TIMEOUT); 380} 381 382/* 383 * Like stall(), but doesn't sleep. 384 * If cpp had variadic macros, the two functions could be #defines for another. 385 * NB: should send a message to the session logger to avoid blocking. 386 */ 387void 388#ifdef __STDC__ 389warning(char *message, ...) 390#else 391warning(va_alist) 392 va_dcl 393#endif 394{ 395 va_list ap; 396#ifndef __STDC__ 397 char *message; 398 399 va_start(ap); 400 message = va_arg(ap, char *); 401#else 402 va_start(ap, message); 403#endif 404 405 vsyslog(LOG_ALERT, message, ap); 406 va_end(ap); 407} 408 409/* 410 * Log an emergency message. 411 * NB: should send a message to the session logger to avoid blocking. 412 */ 413void 414#ifdef __STDC__ 415emergency(char *message, ...) 416#else 417emergency(va_alist) 418 va_dcl 419#endif 420{ 421 va_list ap; 422#ifndef __STDC__ 423 char *message; 424 425 va_start(ap); 426 message = va_arg(ap, char *); 427#else 428 va_start(ap, message); 429#endif 430 431 vsyslog(LOG_EMERG, message, ap); 432 va_end(ap); 433} 434 435/* 436 * Catch a SIGSYS signal. 437 * 438 * These may arise if a system does not support sysctl. 439 * We tolerate up to 25 of these, then throw in the towel. 440 */ 441void 442badsys(sig) 443 int sig; 444{ 445 static int badcount = 0; 446 447 if (badcount++ < 25) 448 return; 449 disaster(sig); 450} 451 452/* 453 * Catch an unexpected signal. 454 */ 455void 456disaster(sig) 457 int sig; 458{ 459 emergency("fatal signal: %s", 460 sig < (unsigned) NSIG ? sys_siglist[sig] : "unknown signal"); 461 462 sleep(STALL_TIMEOUT); 463 _exit(sig); /* reboot */ 464} 465 466/* 467 * Get the security level of the kernel. 468 */ 469int 470getsecuritylevel() 471{ 472#ifdef KERN_SECURELVL 473 int name[2], curlevel; 474 size_t len; 475 extern int errno; 476 477 name[0] = CTL_KERN; 478 name[1] = KERN_SECURELVL; 479 len = sizeof curlevel; 480 if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) { 481 emergency("cannot get kernel security level: %s", 482 strerror(errno)); 483 return (-1); 484 } 485 return (curlevel); 486#else 487 return (-1); 488#endif 489} 490 491/* 492 * Set the security level of the kernel. 493 */ 494void 495setsecuritylevel(newlevel) 496 int newlevel; 497{ 498#ifdef KERN_SECURELVL 499 int name[2], curlevel; 500 extern int errno; 501 502 curlevel = getsecuritylevel(); 503 if (newlevel == curlevel) 504 return; 505 name[0] = CTL_KERN; 506 name[1] = KERN_SECURELVL; 507 if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) { 508 emergency( 509 "cannot change kernel security level from %d to %d: %s", 510 curlevel, newlevel, strerror(errno)); 511 return; 512 } 513#ifdef SECURE 514 warning("kernel security level changed from %d to %d", 515 curlevel, newlevel); 516#endif 517#endif 518} 519 520/* 521 * Change states in the finite state machine. 522 * The initial state is passed as an argument. 523 */ 524void 525transition(s) 526 state_t s; 527{ 528 for (;;) 529 s = (state_t) (*s)(); 530} 531 532/* 533 * Close out the accounting files for a login session. 534 * NB: should send a message to the session logger to avoid blocking. 535 */ 536void 537clear_session_logs(sp) 538 session_t *sp; 539{ 540 char *line = sp->se_device + sizeof(_PATH_DEV) - 1; 541 542 if (logout(line)) 543 logwtmp(line, "", ""); 544} 545 546/* 547 * Start a session and allocate a controlling terminal. 548 * Only called by children of init after forking. 549 */ 550void 551setctty(name) 552 char *name; 553{ 554 int fd; 555 556 (void) revoke(name); 557 if ((fd = open(name, O_RDWR)) == -1) { 558 stall("can't open %s: %m", name); 559 _exit(1); 560 } 561 if (login_tty(fd) == -1) { 562 stall("can't get %s for controlling terminal: %m", name); 563 _exit(1); 564 } 565} 566 567/* 568 * Bring the system up single user. 569 */ 570state_func_t 571single_user() 572{ 573 pid_t pid, wpid; 574 int status; 575 sigset_t mask; 576 char *shell = _PATH_BSHELL; 577 char *argv[2]; 578#ifdef SECURE 579 struct ttyent *typ; 580 struct passwd *pp; 581 static const char banner[] = 582 "Enter root password, or ^D to go multi-user\n"; 583 char *clear, *password; 584#endif 585 586 /* 587 * If the kernel is in secure mode, downgrade it to insecure mode. 588 */ 589 if (getsecuritylevel() > 0) 590 setsecuritylevel(0); 591 592 if (Reboot) { 593 /* Instead of going single user, let's halt the machine */ 594 sync(); 595 alarm(2); 596 pause(); 597 reboot(RB_AUTOBOOT); 598 _exit(0); 599 } 600 601 if ((pid = fork()) == 0) { 602 /* 603 * Start the single user session. 604 */ 605 setctty(_PATH_CONSOLE); 606 607#ifdef SECURE 608 /* 609 * Check the root password. 610 * We don't care if the console is 'on' by default; 611 * it's the only tty that can be 'off' and 'secure'. 612 */ 613 typ = getttynam("console"); 614 pp = getpwnam("root"); 615 if (typ && (typ->ty_status & TTY_SECURE) == 0 && pp && *pp->pw_passwd) { 616 write(2, banner, sizeof banner - 1); 617 for (;;) { 618 clear = getpass("Password:"); 619 if (clear == 0 || *clear == '\0') 620 _exit(0); 621 password = crypt(clear, pp->pw_passwd); 622 bzero(clear, _PASSWORD_LEN); 623 if (strcmp(password, pp->pw_passwd) == 0) 624 break; 625 warning("single-user login failed\n"); 626 } 627 } 628 endttyent(); 629 endpwent(); 630#endif /* SECURE */ 631 632#ifdef DEBUGSHELL 633 { 634 char altshell[128], *cp = altshell; 635 int num; 636 637#define SHREQUEST \ 638 "Enter pathname of shell or RETURN for sh: " 639 (void)write(STDERR_FILENO, 640 SHREQUEST, sizeof(SHREQUEST) - 1); 641 while ((num = read(STDIN_FILENO, cp, 1)) != -1 && 642 num != 0 && *cp != '\n' && cp < &altshell[127]) 643 cp++; 644 *cp = '\0'; 645 if (altshell[0] != '\0') 646 shell = altshell; 647 } 648#endif /* DEBUGSHELL */ 649 650 /* 651 * Unblock signals. 652 * We catch all the interesting ones, 653 * and those are reset to SIG_DFL on exec. 654 */ 655 sigemptyset(&mask); 656 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 657 658 /* 659 * Fire off a shell. 660 * If the default one doesn't work, try the Bourne shell. 661 */ 662 argv[0] = "-sh"; 663 argv[1] = 0; 664 execv(shell, argv); 665 emergency("can't exec %s for single user: %m", shell); 666 execv(_PATH_BSHELL, argv); 667 emergency("can't exec %s for single user: %m", _PATH_BSHELL); 668 sleep(STALL_TIMEOUT); 669 _exit(1); 670 } 671 672 if (pid == -1) { 673 /* 674 * We are seriously hosed. Do our best. 675 */ 676 emergency("can't fork single-user shell, trying again"); 677 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 678 continue; 679 return (state_func_t) single_user; 680 } 681 682 requested_transition = 0; 683 do { 684 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 685 collect_child(wpid); 686 if (wpid == -1) { 687 if (errno == EINTR) 688 continue; 689 warning("wait for single-user shell failed: %m; restarting"); 690 return (state_func_t) single_user; 691 } 692 if (wpid == pid && WIFSTOPPED(status)) { 693 warning("init: shell stopped, restarting\n"); 694 kill(pid, SIGCONT); 695 wpid = -1; 696 } 697 } while (wpid != pid && !requested_transition); 698 699 if (requested_transition) 700 return (state_func_t) requested_transition; 701 702 if (!WIFEXITED(status)) { 703 if (WTERMSIG(status) == SIGKILL) { 704 /* 705 * reboot(8) killed shell? 706 */ 707 warning("single user shell terminated."); 708 sleep(STALL_TIMEOUT); 709 _exit(0); 710 } else { 711 warning("single user shell terminated, restarting"); 712 return (state_func_t) single_user; 713 } 714 } 715 716 runcom_mode = FASTBOOT; 717 return (state_func_t) runcom; 718} 719 720/* 721 * Run the system startup script. 722 */ 723state_func_t 724runcom() 725{ 726 pid_t pid, wpid; 727 int status; 728 char *argv[4]; 729 struct sigaction sa; 730 731 if ((pid = fork()) == 0) { 732 sigemptyset(&sa.sa_mask); 733 sa.sa_flags = 0; 734 sa.sa_handler = SIG_IGN; 735 (void) sigaction(SIGTSTP, &sa, (struct sigaction *)0); 736 (void) sigaction(SIGHUP, &sa, (struct sigaction *)0); 737 738 setctty(_PATH_CONSOLE); 739 740 argv[0] = "sh"; 741 argv[1] = _PATH_RUNCOM; 742 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0; 743 argv[3] = 0; 744 745 sigprocmask(SIG_SETMASK, &sa.sa_mask, (sigset_t *) 0); 746 747#ifdef LOGIN_CAP 748 setprocresources(RESOURCE_RC); 749#endif 750 execv(_PATH_BSHELL, argv); 751 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM); 752 _exit(1); /* force single user mode */ 753 } 754 755 if (pid == -1) { 756 emergency("can't fork for %s on %s: %m", 757 _PATH_BSHELL, _PATH_RUNCOM); 758 while (waitpid(-1, (int *) 0, WNOHANG) > 0) 759 continue; 760 sleep(STALL_TIMEOUT); 761 return (state_func_t) single_user; 762 } 763 764 /* 765 * Copied from single_user(). This is a bit paranoid. 766 */ 767 do { 768 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1) 769 collect_child(wpid); 770 if (wpid == -1) { 771 if (errno == EINTR) 772 continue; 773 warning("wait for %s on %s failed: %m; going to single user mode", 774 _PATH_BSHELL, _PATH_RUNCOM); 775 return (state_func_t) single_user; 776 } 777 if (wpid == pid && WIFSTOPPED(status)) { 778 warning("init: %s on %s stopped, restarting\n", 779 _PATH_BSHELL, _PATH_RUNCOM); 780 kill(pid, SIGCONT); 781 wpid = -1; 782 } 783 } while (wpid != pid); 784 785 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM && 786 requested_transition == catatonia) { 787 /* /etc/rc executed /sbin/reboot; wait for the end quietly */ 788 sigset_t s; 789 790 sigfillset(&s); 791 for (;;) 792 sigsuspend(&s); 793 } 794 795 if (!WIFEXITED(status)) { 796 warning("%s on %s terminated abnormally, going to single user mode", 797 _PATH_BSHELL, _PATH_RUNCOM); 798 return (state_func_t) single_user; 799 } 800 801 if (WEXITSTATUS(status)) 802 return (state_func_t) single_user; 803 804 runcom_mode = AUTOBOOT; /* the default */ 805 /* NB: should send a message to the session logger to avoid blocking. */ 806 logwtmp("~", "reboot", ""); 807 return (state_func_t) read_ttys; 808} 809 810/* 811 * Open the session database. 812 * 813 * NB: We could pass in the size here; is it necessary? 814 */ 815int 816start_session_db() 817{ 818 if (session_db && (*session_db->close)(session_db)) 819 emergency("session database close: %s", strerror(errno)); 820 if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == 0) { 821 emergency("session database open: %s", strerror(errno)); 822 return (1); 823 } 824 return (0); 825 826} 827 828/* 829 * Add a new login session. 830 */ 831void 832add_session(sp) 833 session_t *sp; 834{ 835 DBT key; 836 DBT data; 837 838 key.data = &sp->se_process; 839 key.size = sizeof sp->se_process; 840 data.data = &sp; 841 data.size = sizeof sp; 842 843 if ((*session_db->put)(session_db, &key, &data, 0)) 844 emergency("insert %d: %s", sp->se_process, strerror(errno)); 845} 846 847/* 848 * Delete an old login session. 849 */ 850void 851del_session(sp) 852 session_t *sp; 853{ 854 DBT key; 855 856 key.data = &sp->se_process; 857 key.size = sizeof sp->se_process; 858 859 if ((*session_db->del)(session_db, &key, 0)) 860 emergency("delete %d: %s", sp->se_process, strerror(errno)); 861} 862 863/* 864 * Look up a login session by pid. 865 */ 866session_t * 867#ifdef __STDC__ 868find_session(pid_t pid) 869#else 870find_session(pid) 871 pid_t pid; 872#endif 873{ 874 DBT key; 875 DBT data; 876 session_t *ret; 877 878 key.data = &pid; 879 key.size = sizeof pid; 880 if ((*session_db->get)(session_db, &key, &data, 0) != 0) 881 return 0; 882 bcopy(data.data, (char *)&ret, sizeof(ret)); 883 return ret; 884} 885 886/* 887 * Construct an argument vector from a command line. 888 */ 889char ** 890construct_argv(command) 891 char *command; 892{ 893 char *strk (char *); 894 register int argc = 0; 895 register char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1) 896 * sizeof (char *)); 897 898 if ((argv[argc++] = strk(command)) == 0) 899 return 0; 900 while (argv[argc++] = strk((char *) 0)) 901 continue; 902 return argv; 903} 904 905/* 906 * Deallocate a session descriptor. 907 */ 908void 909free_session(sp) 910 register session_t *sp; 911{ 912 free(sp->se_device); 913 if (sp->se_getty) { 914 free(sp->se_getty); 915 free(sp->se_getty_argv_space); 916 free(sp->se_getty_argv); 917 } 918 if (sp->se_window) { 919 free(sp->se_window); 920 free(sp->se_window_argv_space); 921 free(sp->se_window_argv); 922 } 923 if (sp->se_type) 924 free(sp->se_type); 925 free(sp); 926} 927 928/* 929 * Allocate a new session descriptor. 930 */ 931session_t * 932new_session(sprev, session_index, typ) 933 session_t *sprev; 934 int session_index; 935 register struct ttyent *typ; 936{ 937 register session_t *sp; 938 939 if ((typ->ty_status & TTY_ON) == 0 || 940 typ->ty_name == 0 || 941 typ->ty_getty == 0) 942 return 0; 943 944 sp = (session_t *) malloc(sizeof (session_t)); 945 bzero(sp, sizeof *sp); 946 947 sp->se_index = session_index; 948 949 sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name)); 950 (void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name); 951 952 if (setupargv(sp, typ) == 0) { 953 free_session(sp); 954 return (0); 955 } 956 957 sp->se_next = 0; 958 if (sprev == 0) { 959 sessions = sp; 960 sp->se_prev = 0; 961 } else { 962 sprev->se_next = sp; 963 sp->se_prev = sprev; 964 } 965 966 return sp; 967} 968 969/* 970 * Calculate getty and if useful window argv vectors. 971 */ 972int 973setupargv(sp, typ) 974 session_t *sp; 975 struct ttyent *typ; 976{ 977 978 if (sp->se_getty) { 979 free(sp->se_getty); 980 free(sp->se_getty_argv_space); 981 free(sp->se_getty_argv); 982 } 983 sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2); 984 (void) sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name); 985 sp->se_getty_argv_space = strdup(sp->se_getty); 986 sp->se_getty_argv = construct_argv(sp->se_getty_argv_space); 987 if (sp->se_getty_argv == 0) { 988 warning("can't parse getty for port %s", sp->se_device); 989 free(sp->se_getty); 990 free(sp->se_getty_argv_space); 991 sp->se_getty = sp->se_getty_argv_space = 0; 992 return (0); 993 } 994 if (sp->se_window) { 995 free(sp->se_window); 996 free(sp->se_window_argv_space); 997 free(sp->se_window_argv); 998 } 999 sp->se_window = sp->se_window_argv_space = 0; 1000 sp->se_window_argv = 0; 1001 if (typ->ty_window) { 1002 sp->se_window = strdup(typ->ty_window); 1003 sp->se_window_argv_space = strdup(sp->se_window); 1004 sp->se_window_argv = construct_argv(sp->se_window_argv_space); 1005 if (sp->se_window_argv == 0) { 1006 warning("can't parse window for port %s", 1007 sp->se_device); 1008 free(sp->se_window_argv_space); 1009 free(sp->se_window); 1010 sp->se_window = sp->se_window_argv_space = 0; 1011 return (0); 1012 } 1013 } 1014 if (sp->se_type) 1015 free(sp->se_type); 1016 sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0; 1017 return (1); 1018} 1019 1020/* 1021 * Walk the list of ttys and create sessions for each active line. 1022 */ 1023state_func_t 1024read_ttys() 1025{ 1026 int session_index = 0; 1027 register session_t *sp, *snext; 1028 register struct ttyent *typ; 1029 1030 /* 1031 * Destroy any previous session state. 1032 * There shouldn't be any, but just in case... 1033 */ 1034 for (sp = sessions; sp; sp = snext) { 1035 if (sp->se_process) 1036 clear_session_logs(sp); 1037 snext = sp->se_next; 1038 free_session(sp); 1039 } 1040 sessions = 0; 1041 if (start_session_db()) 1042 return (state_func_t) single_user; 1043 1044 /* 1045 * Allocate a session entry for each active port. 1046 * Note that sp starts at 0. 1047 */ 1048 while (typ = getttyent()) 1049 if (snext = new_session(sp, ++session_index, typ)) 1050 sp = snext; 1051 1052 endttyent(); 1053 1054 return (state_func_t) multi_user; 1055} 1056 1057/* 1058 * Start a window system running. 1059 */ 1060void 1061start_window_system(sp) 1062 session_t *sp; 1063{ 1064 pid_t pid; 1065 sigset_t mask; 1066 char term[64], *env[2]; 1067 1068 if ((pid = fork()) == -1) { 1069 emergency("can't fork for window system on port %s: %m", 1070 sp->se_device); 1071 /* hope that getty fails and we can try again */ 1072 return; 1073 } 1074 1075 if (pid) 1076 return; 1077 1078 sigemptyset(&mask); 1079 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1080 1081 if (setsid() < 0) 1082 emergency("setsid failed (window) %m"); 1083 1084#ifdef LOGIN_CAP 1085 setprocresources(RESOURCE_WINDOW); 1086#endif 1087 if (sp->se_type) { 1088 /* Don't use malloc after fork */ 1089 strcpy(term, "TERM="); 1090 strncat(term, sp->se_type, sizeof(term) - 6); 1091 env[0] = term; 1092 env[1] = 0; 1093 } 1094 else 1095 env[0] = 0; 1096 execve(sp->se_window_argv[0], sp->se_window_argv, env); 1097 stall("can't exec window system '%s' for port %s: %m", 1098 sp->se_window_argv[0], sp->se_device); 1099 _exit(1); 1100} 1101 1102/* 1103 * Start a login session running. 1104 */ 1105pid_t 1106start_getty(sp) 1107 session_t *sp; 1108{ 1109 pid_t pid; 1110 sigset_t mask; 1111 time_t current_time = time((time_t *) 0); 1112 int too_quick = 0; 1113 char term[64], *env[2]; 1114 1115 if (current_time >= sp->se_started && 1116 current_time - sp->se_started < GETTY_SPACING) { 1117 if (++sp->se_nspace > GETTY_NSPACE) { 1118 sp->se_nspace = 0; 1119 too_quick = 1; 1120 } 1121 } else 1122 sp->se_nspace = 0; 1123 1124 /* 1125 * fork(), not vfork() -- we can't afford to block. 1126 */ 1127 if ((pid = fork()) == -1) { 1128 emergency("can't fork for getty on port %s: %m", sp->se_device); 1129 return -1; 1130 } 1131 1132 if (pid) 1133 return pid; 1134 1135 if (too_quick) { 1136 warning("getty repeating too quickly on port %s, sleeping %d secs", 1137 sp->se_device, GETTY_SLEEP); 1138 sleep((unsigned) GETTY_SLEEP); 1139 } 1140 1141 if (sp->se_window) { 1142 start_window_system(sp); 1143 sleep(WINDOW_WAIT); 1144 } 1145 1146 sigemptyset(&mask); 1147 sigprocmask(SIG_SETMASK, &mask, (sigset_t *) 0); 1148 1149#ifdef LOGIN_CAP 1150 setprocresources(RESOURCE_GETTY); 1151#endif 1152 if (sp->se_type) { 1153 /* Don't use malloc after fork */ 1154 strcpy(term, "TERM="); 1155 strncat(term, sp->se_type, sizeof(term) - 6); 1156 env[0] = term; 1157 env[1] = 0; 1158 } 1159 else 1160 env[0] = 0; 1161 execve(sp->se_getty_argv[0], sp->se_getty_argv, env); 1162 stall("can't exec getty '%s' for port %s: %m", 1163 sp->se_getty_argv[0], sp->se_device); 1164 _exit(1); 1165} 1166 1167/* 1168 * Collect exit status for a child. 1169 * If an exiting login, start a new login running. 1170 */ 1171void 1172#ifdef __STDC__ 1173collect_child(pid_t pid) 1174#else 1175collect_child(pid) 1176 pid_t pid; 1177#endif 1178{ 1179 register session_t *sp, *sprev, *snext; 1180 1181 if (! sessions) 1182 return; 1183 1184 if (! (sp = find_session(pid))) 1185 return; 1186 1187 clear_session_logs(sp); 1188 del_session(sp); 1189 sp->se_process = 0; 1190 1191 if (sp->se_flags & SE_SHUTDOWN) { 1192 if (sprev = sp->se_prev) 1193 sprev->se_next = sp->se_next; 1194 else 1195 sessions = sp->se_next; 1196 if (snext = sp->se_next) 1197 snext->se_prev = sp->se_prev; 1198 free_session(sp); 1199 return; 1200 } 1201 1202 if ((pid = start_getty(sp)) == -1) { 1203 /* serious trouble */ 1204 requested_transition = clean_ttys; 1205 return; 1206 } 1207 1208 sp->se_process = pid; 1209 sp->se_started = time((time_t *) 0); 1210 add_session(sp); 1211} 1212 1213/* 1214 * Catch a signal and request a state transition. 1215 */ 1216void 1217transition_handler(sig) 1218 int sig; 1219{ 1220 1221 switch (sig) { 1222 case SIGHUP: 1223 requested_transition = clean_ttys; 1224 break; 1225 case SIGINT: 1226 Reboot = TRUE; 1227 case SIGTERM: 1228 requested_transition = death; 1229 break; 1230 case SIGTSTP: 1231 requested_transition = catatonia; 1232 break; 1233 default: 1234 requested_transition = 0; 1235 break; 1236 } 1237} 1238 1239/* 1240 * Take the system multiuser. 1241 */ 1242state_func_t 1243multi_user() 1244{ 1245 pid_t pid; 1246 register session_t *sp; 1247 1248 requested_transition = 0; 1249 1250 /* 1251 * If the administrator has not set the security level to -1 1252 * to indicate that the kernel should not run multiuser in secure 1253 * mode, and the run script has not set a higher level of security 1254 * than level 1, then put the kernel into secure mode. 1255 */ 1256 if (getsecuritylevel() == 0) 1257 setsecuritylevel(1); 1258 1259 for (sp = sessions; sp; sp = sp->se_next) { 1260 if (sp->se_process) 1261 continue; 1262 if ((pid = start_getty(sp)) == -1) { 1263 /* serious trouble */ 1264 requested_transition = clean_ttys; 1265 break; 1266 } 1267 sp->se_process = pid; 1268 sp->se_started = time((time_t *) 0); 1269 add_session(sp); 1270 } 1271 1272 while (!requested_transition) 1273 if ((pid = waitpid(-1, (int *) 0, 0)) != -1) 1274 collect_child(pid); 1275 1276 return (state_func_t) requested_transition; 1277} 1278 1279/* 1280 * This is an n-squared algorithm. We hope it isn't run often... 1281 */ 1282state_func_t 1283clean_ttys() 1284{ 1285 register session_t *sp, *sprev; 1286 register struct ttyent *typ; 1287 register int session_index = 0; 1288 register int devlen; 1289 char *old_getty, *old_window, *old_type; 1290 1291 if (! sessions) 1292 return (state_func_t) multi_user; 1293 1294 devlen = sizeof(_PATH_DEV) - 1; 1295 while (typ = getttyent()) { 1296 ++session_index; 1297 1298 for (sprev = 0, sp = sessions; sp; sprev = sp, sp = sp->se_next) 1299 if (strcmp(typ->ty_name, sp->se_device + devlen) == 0) 1300 break; 1301 1302 if (sp) { 1303 if (sp->se_index != session_index) { 1304 warning("port %s changed utmp index from %d to %d", 1305 sp->se_device, sp->se_index, 1306 session_index); 1307 sp->se_index = session_index; 1308 } 1309 if ((typ->ty_status & TTY_ON) == 0 || 1310 typ->ty_getty == 0) { 1311 sp->se_flags |= SE_SHUTDOWN; 1312 kill(sp->se_process, SIGHUP); 1313 continue; 1314 } 1315 sp->se_flags &= ~SE_SHUTDOWN; 1316 old_getty = sp->se_getty ? strdup(sp->se_getty) : 0; 1317 old_window = sp->se_window ? strdup(sp->se_window) : 0; 1318 old_type = sp->se_type ? strdup(sp->se_type) : 0; 1319 if (setupargv(sp, typ) == 0) { 1320 warning("can't parse getty for port %s", 1321 sp->se_device); 1322 sp->se_flags |= SE_SHUTDOWN; 1323 kill(sp->se_process, SIGHUP); 1324 } 1325 else if ( !old_getty 1326 || !old_type && sp->se_type 1327 || old_type && !sp->se_type 1328 || !old_window && sp->se_window 1329 || old_window && !sp->se_window 1330 || strcmp(old_getty, sp->se_getty) != 0 1331 || old_window && strcmp(old_window, sp->se_window) != 0 1332 || old_type && strcmp(old_type, sp->se_type) != 0 1333 ) { 1334 /* Don't set SE_SHUTDOWN here */ 1335 sp->se_nspace = 0; 1336 sp->se_started = 0; 1337 kill(sp->se_process, SIGHUP); 1338 } 1339 if (old_getty) 1340 free(old_getty); 1341 if (old_getty) 1342 free(old_window); 1343 if (old_type) 1344 free(old_type); 1345 continue; 1346 } 1347 1348 new_session(sprev, session_index, typ); 1349 } 1350 1351 endttyent(); 1352 1353 return (state_func_t) multi_user; 1354} 1355 1356/* 1357 * Block further logins. 1358 */ 1359state_func_t 1360catatonia() 1361{ 1362 register session_t *sp; 1363 1364 for (sp = sessions; sp; sp = sp->se_next) 1365 sp->se_flags |= SE_SHUTDOWN; 1366 1367 return (state_func_t) multi_user; 1368} 1369 1370/* 1371 * Note SIGALRM. 1372 */ 1373void 1374alrm_handler(sig) 1375 int sig; 1376{ 1377 clang = 1; 1378} 1379 1380/* 1381 * Bring the system down to single user. 1382 */ 1383state_func_t 1384death() 1385{ 1386 register session_t *sp; 1387 register int i; 1388 pid_t pid; 1389 static const int death_sigs[3] = { SIGHUP, SIGTERM, SIGKILL }; 1390 1391 for (sp = sessions; sp; sp = sp->se_next) 1392 sp->se_flags |= SE_SHUTDOWN; 1393 1394 /* NB: should send a message to the session logger to avoid blocking. */ 1395 logwtmp("~", "shutdown", ""); 1396 1397 for (i = 0; i < 3; ++i) { 1398 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH) 1399 return (state_func_t) single_user; 1400 1401 clang = 0; 1402 alarm(DEATH_WATCH); 1403 do 1404 if ((pid = waitpid(-1, (int *)0, 0)) != -1) 1405 collect_child(pid); 1406 while (clang == 0 && errno != ECHILD); 1407 1408 if (errno == ECHILD) 1409 return (state_func_t) single_user; 1410 } 1411 1412 warning("some processes would not die; ps axl advised"); 1413 1414 return (state_func_t) single_user; 1415} 1416char * 1417strk (char *p) 1418{ 1419 static char *t; 1420 char *q; 1421 int c; 1422 1423 if (p) 1424 t = p; 1425 if (!t) 1426 return 0; 1427 1428 c = *t; 1429 while (c == ' ' || c == '\t' ) 1430 c = *++t; 1431 if (!c) { 1432 t = 0; 1433 return 0; 1434 } 1435 q = t; 1436 if (c == '\'') { 1437 c = *++t; 1438 q = t; 1439 while (c && c != '\'') 1440 c = *++t; 1441 if (!c) /* unterminated string */ 1442 q = t = 0; 1443 else 1444 *t++ = 0; 1445 } else { 1446 while (c && c != ' ' && c != '\t' ) 1447 c = *++t; 1448 *t++ = 0; 1449 if (!c) 1450 t = 0; 1451 } 1452 return q; 1453} 1454 1455#ifdef LOGIN_CAP 1456void 1457setprocresources(cname) 1458 const char *cname; 1459{ 1460 login_cap_t *lc; 1461 if ((lc = login_getclassbyname(cname, (char*)NULL)) != NULL) { 1462 setusercontext(lc, (struct passwd*)NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES); 1463 login_close(lc); 1464 } 1465} 1466#endif 1467