sbin/init/init.c

   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. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
  33  * @(#)init.c   8.1 (Berkeley) 7/15/93
  34  * $FreeBSD: src/sbin/init/init.c,v 1.38.2.8 2001/10/22 11:27:32 des Exp $
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/mount.h>
  40 #include <sys/sysctl.h>
  41 #include <sys/wait.h>
  42 #include <sys/stat.h>
  43
  44 #include <db.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <libutil.h>
  48 #include <utmpx.h>
  49 #include <paths.h>
  50 #include <signal.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <syslog.h>
  55 #include <time.h>
  56 #include <ttyent.h>
  57 #include <unistd.h>
  58 #include <sys/reboot.h>
  59 #include <err.h>
  60
  61 #include <stdarg.h>
  62
  63 #ifdef SECURE
  64 #include <pwd.h>
  65 #endif
  66
  67 #ifdef LOGIN_CAP
  68 #include <login_cap.h>
  69 #endif
  70
  71 #include "pathnames.h"
  72
  73 /*
  74  * Sleep times; used to prevent thrashing.
  75  */
  76 #define GETTY_SPACING            5      /* N secs minimum getty spacing */
  77 #define GETTY_SLEEP             30      /* sleep N secs after spacing problem */
  78 #define GETTY_NSPACE             3      /* max. spacing count to bring reaction */
  79 #define WINDOW_WAIT              3      /* wait N secs after starting window */
  80 #define STALL_TIMEOUT           30      /* wait N secs after warning */
  81 #define DEATH_WATCH             10      /* wait N secs for procs to die */
  82 #define DEATH_SCRIPT            120     /* wait for 2min for /etc/rc.shutdown */
  83
  84 /*
  85  * User-based resource limits.
  86  */
  87 #define RESOURCE_RC             "daemon"
  88 #define RESOURCE_WINDOW         "default"
  89 #define RESOURCE_GETTY          "default"
  90
  91 #ifndef DEFAULT_STATE
  92 #define DEFAULT_STATE           runcom
  93 #endif
  94
  95 typedef enum {
  96         invalid_state,
  97         single_user,
  98         runcom,
  99         read_ttys,
 100         multi_user,
 101         clean_ttys,
 102         catatonia,
 103         death
 104 } state_t;
 105 typedef state_t (*state_func_t)(void);
 106
 107 static state_t f_single_user(void);
 108 static state_t f_runcom(void);
 109 static state_t f_read_ttys(void);
 110 static state_t f_multi_user(void);
 111 static state_t f_clean_ttys(void);
 112 static state_t f_catatonia(void);
 113 static state_t f_death(void);
 114
 115 state_func_t state_funcs[] = {
 116         NULL,
 117         f_single_user,
 118         f_runcom,
 119         f_read_ttys,
 120         f_multi_user,
 121         f_clean_ttys,
 122         f_catatonia,
 123         f_death
 124 };
 125
 126 enum { AUTOBOOT, FASTBOOT } runcom_mode = AUTOBOOT;
 127 #define FALSE   0
 128 #define TRUE    1
 129
 130 static void transition(state_t);
 131 static volatile sig_atomic_t requested_transition = DEFAULT_STATE;
 132
 133 static void     setctty(const char *);
 134
 135 typedef struct init_session {
 136         int     se_index;               /* index of entry in ttys file */
 137         pid_t   se_process;             /* controlling process */
 138         struct timeval  se_started;             /* used to avoid thrashing */
 139         int     se_flags;               /* status of session */
 140 #define SE_SHUTDOWN     0x1             /* session won't be restarted */
 141 #define SE_PRESENT      0x2             /* session is in /etc/ttys */
 142         int     se_nspace;              /* spacing count */
 143         char    *se_device;             /* filename of port */
 144         char    *se_getty;              /* what to run on that port */
 145         char    *se_getty_argv_space;   /* pre-parsed argument array space */
 146         char    **se_getty_argv;        /* pre-parsed argument array */
 147         char    *se_window;             /* window system (started only once) */
 148         char    *se_window_argv_space;  /* pre-parsed argument array space */
 149         char    **se_window_argv;       /* pre-parsed argument array */
 150         char    *se_type;               /* default terminal type */
 151         struct  init_session *se_prev;
 152         struct  init_session *se_next;
 153 } session_t;
 154
 155 static void      handle(sig_t, ...);
 156 static void      delset(sigset_t *, ...);
 157
 158 static void      stall(const char *, ...) __printflike(1, 2);
 159 static void      warning(const char *, ...) __printflike(1, 2);
 160 static void      emergency(const char *, ...) __printflike(1, 2);
 161 static void      disaster(int);
 162 static void      badsys(int);
 163 static int       runshutdown(void);
 164 static char     *strk(char *);
 165
 166 #define DEATH           'd'
 167 #define SINGLE_USER     's'
 168 #define RUNCOM          'r'
 169 #define READ_TTYS       't'
 170 #define MULTI_USER      'm'
 171 #define CLEAN_TTYS      'T'
 172 #define CATATONIA       'c'
 173
 174 static void     free_session(session_t *);
 175 static session_t *new_session(session_t *, int, struct ttyent *);
 176 static void     adjttyent(struct ttyent *typ);
 177
 178 static char     **construct_argv(char *);
 179 static void     start_window_system(session_t *);
 180 static void     collect_child(pid_t);
 181 static pid_t    start_getty(session_t *);
 182 static void     transition_handler(int);
 183 static void     alrm_handler(int);
 184 static void     setsecuritylevel(int);
 185 static int      getsecuritylevel(void);
 186 static char     *get_chroot(void);
 187 static int      setupargv(session_t *, struct ttyent *);
 188 #ifdef LOGIN_CAP
 189 static void     setprocresources(const char *);
 190 #endif
 191
 192 static void     clear_session_logs(session_t *);
 193
 194 static int      start_session_db(void);
 195 static void     add_session(session_t *);
 196 static void     del_session(session_t *);
 197 static session_t *find_session(pid_t);
 198
 199 #ifdef SUPPORT_UTMPX
 200 static struct timeval boot_time;
 201 state_t current_state = death;
 202 static void session_utmpx(const session_t *, int);
 203 static void make_utmpx(const char *, const char *, int, pid_t,
 204     const struct timeval *, int);
 205 static char get_runlevel(const state_t);
 206 static void utmpx_set_runlevel(char, char);
 207 #endif
 208
 209 static int Reboot = FALSE;
 210 static int howto = RB_AUTOBOOT;
 211
 212 static DB *session_db;
 213 static volatile sig_atomic_t clang;
 214 static session_t *sessions;
 215
 216 /*
 217  * The mother of all processes.
 218  */
 219 int
 220 main(int argc, char *argv[])
 221 {
 222         char *init_chroot;
 223         int c;
 224         struct sigaction sa;
 225         sigset_t mask;
 226         struct stat sts;
 227
 228 #ifdef SUPPORT_UTMPX
 229         (void)gettimeofday(&boot_time, NULL);
 230 #endif /* SUPPORT_UTMPX */
 231
 232         /* Dispose of random users. */
 233         if (getuid() != 0)
 234                 errx(1, "%s", strerror(EPERM));
 235
 236         /* System V users like to reexec init. */
 237         if (getpid() != 1) {
 238 #ifdef COMPAT_SYSV_INIT
 239                 /* So give them what they want */
 240                 if (argc > 1) {
 241                         if (strlen(argv[1]) == 1) {
 242                                 char runlevel = *argv[1];
 243                                 int sig;
 244
 245                                 switch (runlevel) {
 246                                         case '0': /* halt + poweroff */
 247                                                 sig = SIGUSR2;
 248                                                 break;
 249                                         case '1': /* single-user */
 250                                                 sig = SIGTERM;
 251                                                 break;
 252                                         case '6': /* reboot */
 253                                                 sig = SIGINT;
 254                                                 break;
 255                                         case 'c': /* block further logins */
 256                                                 sig = SIGTSTP;
 257                                                 break;
 258                                         case 'q': /* rescan /etc/ttys */
 259                                                 sig = SIGHUP;
 260                                                 break;
 261                                         default:
 262                                                 goto invalid;
 263                                 }
 264                                 kill(1, sig);
 265                                 _exit(0);
 266                         } else
 267 invalid:
 268                                 errx(1, "invalid run-level ``%s''", argv[1]);
 269                 } else
 270 #endif
 271                         errx(1, "already running");
 272         }
 273         /*
 274          * Note that this does NOT open a file...
 275          * Does 'init' deserve its own facility number?
 276          */
 277         openlog("init", LOG_CONS, LOG_AUTH);
 278
 279         /*
 280          * If chroot has been requested by the boot loader,
 281          * do it now.  Try to be robust:  If the directory
 282          * doesn't exist, continue anyway.
 283          */
 284         init_chroot = get_chroot();
 285         if (init_chroot != NULL) {
 286                 if (chdir(init_chroot) == -1 || chroot(".") == -1)
 287                         warning("can't chroot to %s: %m", init_chroot);
 288                 free(init_chroot);
 289         }
 290
 291         /*
 292          * Create an initial session.
 293          */
 294         if (setsid() < 0)
 295                 warning("initial setsid() failed: %m");
 296
 297         /*
 298          * Establish an initial user so that programs running
 299          * single user do not freak out and die (like passwd).
 300          */
 301         if (setlogin("root") < 0)
 302                 warning("setlogin() failed: %m");
 303
 304         if (stat("/dev/null", &sts) < 0) {
 305                 warning("/dev MAY BE CORRUPT! /dev/null is missing!\n");
 306                 sleep(5);
 307         }
 308
 309         /*
 310          * This code assumes that we always get arguments through flags,
 311          * never through bits set in some random machine register.
 312          */
 313         while ((c = getopt(argc, argv, "dsf")) != -1)
 314                 switch (c) {
 315                 case 'd':
 316                         /* We don't support DEVFS. */
 317                         break;
 318                 case 's':
 319                         requested_transition = single_user;
 320                         break;
 321                 case 'f':
 322                         runcom_mode = FASTBOOT;
 323                         break;
 324                 default:
 325                         warning("unrecognized flag '-%c'", c);
 326                         break;
 327                 }
 328
 329         if (optind != argc)
 330                 warning("ignoring excess arguments");
 331
 332         /*
 333          * We catch or block signals rather than ignore them,
 334          * so that they get reset on exec.
 335          */
 336         handle(badsys, SIGSYS, 0);
 337         handle(disaster, SIGABRT, SIGFPE, SIGILL, SIGSEGV,
 338                SIGBUS, SIGXCPU, SIGXFSZ, 0);
 339         handle(transition_handler, SIGHUP, SIGINT, SIGTERM, SIGTSTP,
 340                 SIGUSR1, SIGUSR2, 0);
 341         handle(alrm_handler, SIGALRM, 0);
 342         sigfillset(&mask);
 343         delset(&mask, SIGABRT, SIGFPE, SIGILL, SIGSEGV, SIGBUS, SIGSYS,
 344                 SIGXCPU, SIGXFSZ, SIGHUP, SIGINT, SIGTERM, SIGTSTP, SIGALRM,
 345                 SIGUSR1, SIGUSR2, 0);
 346         sigprocmask(SIG_SETMASK, &mask, NULL);
 347         sigemptyset(&sa.sa_mask);
 348         sa.sa_flags = 0;
 349         sa.sa_handler = SIG_IGN;
 350         sigaction(SIGTTIN, &sa, NULL);
 351         sigaction(SIGTTOU, &sa, NULL);
 352
 353         /*
 354          * Paranoia.
 355          */
 356         close(0);
 357         close(1);
 358         close(2);
 359
 360         /*
 361          * Start the state machine.
 362          */
 363         transition(requested_transition);
 364
 365         /*
 366          * Should never reach here.
 367          */
 368         return 1;
 369 }
 370
 371 /*
 372  * Associate a function with a signal handler.
 373  */
 374 static void
 375 handle(sig_t handler, ...)
 376 {
 377         int sig;
 378         struct sigaction sa;
 379         sigset_t mask_everything;
 380         va_list ap;
 381
 382         va_start(ap, handler);
 383
 384         sa.sa_handler = handler;
 385         sigfillset(&mask_everything);
 386
 387         while ((sig = va_arg(ap, int)) != 0) {
 388                 sa.sa_mask = mask_everything;
 389                 /* XXX SA_RESTART? */
 390                 sa.sa_flags = sig == SIGCHLD ? SA_NOCLDSTOP : 0;
 391                 sigaction(sig, &sa, NULL);
 392         }
 393         va_end(ap);
 394 }
 395
 396 /*
 397  * Delete a set of signals from a mask.
 398  */
 399 static void
 400 delset(sigset_t *maskp, ...)
 401 {
 402         int sig;
 403         va_list ap;
 404
 405         va_start(ap, maskp);
 406
 407         while ((sig = va_arg(ap, int)) != 0)
 408                 sigdelset(maskp, sig);
 409         va_end(ap);
 410 }
 411
 412 /*
 413  * Log a message and sleep for a while (to give someone an opportunity
 414  * to read it and to save log or hardcopy output if the problem is chronic).
 415  */
 416 static void
 417 stall(const char *message, ...)
 418 {
 419         va_list ap;
 420
 421         va_start(ap, message);
 422
 423         vsyslog(LOG_ALERT, message, ap);
 424         va_end(ap);
 425         sleep(STALL_TIMEOUT);
 426 }
 427
 428 /*
 429  * Like stall(), but doesn't sleep.
 430  * If cpp had variadic macros, the two functions could be #defines for another.
 431  */
 432 static void
 433 warning(const char *message, ...)
 434 {
 435         va_list ap;
 436
 437         va_start(ap, message);
 438
 439         vsyslog(LOG_ALERT, message, ap);
 440         va_end(ap);
 441 }
 442
 443 /*
 444  * Log an emergency message.
 445  */
 446 static void
 447 emergency(const char *message, ...)
 448 {
 449         va_list ap;
 450
 451         va_start(ap, message);
 452
 453         vsyslog(LOG_EMERG, message, ap);
 454         va_end(ap);
 455 }
 456
 457 /*
 458  * Catch a SIGSYS signal.
 459  *
 460  * These may arise if a system does not support sysctl.
 461  * We tolerate up to 25 of these, then throw in the towel.
 462  */
 463 static void
 464 badsys(int sig)
 465 {
 466         static int badcount = 0;
 467
 468         if (badcount++ < 25)
 469                 return;
 470         disaster(sig);
 471 }
 472
 473 /*
 474  * Catch an unexpected signal.
 475  */
 476 static void
 477 disaster(int sig)
 478 {
 479         emergency("fatal signal: %s",
 480                 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
 481
 482         sleep(STALL_TIMEOUT);
 483         _exit(sig);             /* reboot */
 484 }
 485
 486 /*
 487  * Get the security level of the kernel.
 488  */
 489 static int
 490 getsecuritylevel(void)
 491 {
 492 #ifdef KERN_SECURELVL
 493         int name[2], curlevel;
 494         size_t len;
 495
 496         name[0] = CTL_KERN;
 497         name[1] = KERN_SECURELVL;
 498         len = sizeof curlevel;
 499         if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
 500                 emergency("cannot get kernel security level: %s",
 501                     strerror(errno));
 502                 return (-1);
 503         }
 504         return (curlevel);
 505 #else
 506         return (-1);
 507 #endif
 508 }
 509
 510 /*
 511  * Get the value of the "init_chroot" variable from the
 512  * kernel environment (or NULL if not set).
 513  */
 514
 515 static char *
 516 get_chroot(void)
 517 {
 518         static const char ichname[] = "init_chroot=";   /* includes '=' */
 519         const int ichlen = strlen(ichname);
 520         int real_oid[CTL_MAXNAME];
 521         char sbuf[1024];
 522         size_t oidlen, slen;
 523         char *res;
 524         int i;
 525
 526         oidlen = NELEM(real_oid);
 527         if (sysctlnametomib("kern.environment", real_oid, &oidlen)) {
 528                 warning("cannot find kern.environment base sysctl OID");
 529                 return NULL;
 530         }
 531         if (oidlen + 1 >= NELEM(real_oid)) {
 532                 warning("kern.environment OID is too large!");
 533                 return NULL;
 534         }
 535         res = NULL;
 536         real_oid[oidlen] = 0;
 537
 538         for (i = 0; ; i++) {
 539                 real_oid[oidlen + 1] = i;
 540                 slen = sizeof(sbuf);
 541                 if (sysctl(real_oid, oidlen + 2, sbuf, &slen, NULL, 0) < 0) {
 542                         if (errno != ENOENT)
 543                                 warning("sysctl kern.environment.%d: %m", i);
 544                         break;
 545                 }
 546
 547                 /*
 548                  * slen includes the terminating \0, but do a few sanity
 549                  * checks anyway.
 550                  */
 551                 if (slen == 0)
 552                         continue;
 553                 sbuf[slen - 1] = 0;
 554                 if (strncmp(sbuf, ichname, ichlen) != 0)
 555                         continue;
 556                 if (sbuf[ichlen])
 557                         res = strdup(sbuf + ichlen);
 558                 break;
 559         }
 560         return (res);
 561 }
 562
 563 /*
 564  * Set the security level of the kernel.
 565  */
 566 static void
 567 setsecuritylevel(int newlevel)
 568 {
 569 #ifdef KERN_SECURELVL
 570         int name[2], curlevel;
 571
 572         curlevel = getsecuritylevel();
 573         if (newlevel == curlevel)
 574                 return;
 575         name[0] = CTL_KERN;
 576         name[1] = KERN_SECURELVL;
 577         if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
 578                 emergency(
 579                     "cannot change kernel security level from %d to %d: %s",
 580                     curlevel, newlevel, strerror(errno));
 581                 return;
 582         }
 583 #ifdef SECURE
 584         warning("kernel security level changed from %d to %d",
 585             curlevel, newlevel);
 586 #endif
 587 #endif
 588 }
 589
 590 /*
 591  * Change states in the finite state machine.
 592  * The initial state is passed as an argument.
 593  */
 594 static void
 595 transition(state_t s)
 596 {
 597         for (;;) {
 598 #ifdef SUPPORT_UTMPX
 599                 utmpx_set_runlevel(get_runlevel(current_state),
 600                     get_runlevel(s));
 601                 current_state = s;
 602 #endif
 603                 s = (*state_funcs[s])();
 604         }
 605 }
 606
 607 /*
 608  * Close out the accounting files for a login session.
 609  */
 610 static void
 611 clear_session_logs(session_t *sp)
 612 {
 613         char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
 614
 615 #ifdef SUPPORT_UTMPX
 616         if (logoutx(line, 0, DEAD_PROCESS))
 617                  logwtmpx(line, "", "", 0, DEAD_PROCESS);
 618 #endif
 619         if (logout(line))
 620                 logwtmp(line, "", "");
 621 }
 622
 623 /*
 624  * Start a session and allocate a controlling terminal.
 625  * Only called by children of init after forking.
 626  */
 627 static void
 628 setctty(const char *name)
 629 {
 630         int fd;
 631
 632         revoke(name);
 633         if ((fd = open(name, O_RDWR)) == -1) {
 634                 stall("can't open %s: %m", name);
 635                 _exit(1);
 636         }
 637         if (login_tty(fd) == -1) {
 638                 stall("can't get %s for controlling terminal: %m", name);
 639                 _exit(1);
 640         }
 641 }
 642
 643 /*
 644  * Bring the system up single user.
 645  */
 646 static state_t
 647 f_single_user(void)
 648 {
 649         pid_t pid, wpid;
 650         int status;
 651         sigset_t mask;
 652         const char *shell = _PATH_BSHELL;
 653         const char *argv[2];
 654 #ifdef SECURE
 655         struct ttyent *typ;
 656         struct passwd *pp;
 657         static const char banner[] =
 658                 "Enter root password, or ^D to go multi-user\n";
 659         char *clear, *password;
 660 #endif
 661 #ifdef DEBUGSHELL
 662         char altshell[128];
 663 #endif
 664
 665         if (Reboot) {
 666                 /* Instead of going single user, let's reboot the machine */
 667                 sync();
 668                 alarm(2);
 669                 pause();
 670                 reboot(howto);
 671                 _exit(0);
 672         }
 673
 674         if ((pid = fork()) == 0) {
 675                 /*
 676                  * Start the single user session.
 677                  */
 678                 setctty(_PATH_CONSOLE);
 679
 680 #ifdef SECURE
 681                 /*
 682                  * Check the root password.
 683                  * We don't care if the console is 'on' by default;
 684                  * it's the only tty that can be 'off' and 'secure'.
 685                  */
 686                 typ = getttynam("console");
 687                 pp = getpwnam("root");
 688                 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
 689                     pp && *pp->pw_passwd) {
 690                         write(2, banner, sizeof banner - 1);
 691                         for (;;) {
 692                                 clear = getpass("Password:");
 693                                 if (clear == NULL || *clear == '\0')
 694                                         _exit(0);
 695                                 password = crypt(clear, pp->pw_passwd);
 696                                 bzero(clear, _PASSWORD_LEN);
 697                                 if (password != NULL && strcmp(password, pp->pw_passwd) == 0)
 698                                         break;
 699                                 warning("single-user login failed\n");
 700                         }
 701                 }
 702                 endttyent();
 703                 endpwent();
 704 #endif /* SECURE */
 705
 706 #ifdef DEBUGSHELL
 707                 {
 708                         char *cp = altshell;
 709                         int num;
 710
 711 #define SHREQUEST \
 712         "Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
 713                         write(STDERR_FILENO, SHREQUEST, sizeof(SHREQUEST) - 1);
 714                         while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
 715                             num != 0 && *cp != '\n' && cp < &altshell[127])
 716                                         cp++;
 717                         *cp = '\0';
 718                         if (altshell[0] != '\0')
 719                                 shell = altshell;
 720                 }
 721 #endif /* DEBUGSHELL */
 722
 723                 /*
 724                  * Unblock signals.
 725                  * We catch all the interesting ones,
 726                  * and those are reset to SIG_DFL on exec.
 727                  */
 728                 sigemptyset(&mask);
 729                 sigprocmask(SIG_SETMASK, &mask, NULL);
 730
 731                 /*
 732                  * Fire off a shell.
 733                  * If the default one doesn't work, try the Bourne shell.
 734                  */
 735                 argv[0] = "-sh";
 736                 argv[1] = NULL;
 737                 execv(shell, __DECONST(char **, argv));
 738                 emergency("can't exec %s for single user: %m", shell);
 739                 execv(_PATH_BSHELL, __DECONST(char **, argv));
 740                 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
 741                 sleep(STALL_TIMEOUT);
 742                 _exit(1);
 743         }
 744
 745         if (pid == -1) {
 746                 /*
 747                  * We are seriously hosed.  Do our best.
 748                  */
 749                 emergency("can't fork single-user shell, trying again");
 750                 while (waitpid(-1, NULL, WNOHANG) > 0)
 751                         continue;
 752                 return single_user;
 753         }
 754
 755         requested_transition = 0;
 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 single-user shell failed: %m; restarting");
 763                         return single_user;
 764                 }
 765                 if (wpid == pid && WIFSTOPPED(status)) {
 766                         warning("init: shell stopped, restarting\n");
 767                         kill(pid, SIGCONT);
 768                         wpid = -1;
 769                 }
 770         } while (wpid != pid && !requested_transition);
 771
 772         if (requested_transition)
 773                 return requested_transition;
 774
 775         if (!WIFEXITED(status)) {
 776                 if (WTERMSIG(status) == SIGKILL) {
 777                         /*
 778                          *  reboot(8) killed shell?
 779                          */
 780                         warning("single user shell terminated.");
 781                         sleep(STALL_TIMEOUT);
 782                         _exit(0);
 783                 } else {
 784                         warning("single user shell terminated, restarting");
 785                         return single_user;
 786                 }
 787         }
 788
 789         runcom_mode = FASTBOOT;
 790         return runcom;
 791 }
 792
 793 /*
 794  * Run the system startup script.
 795  */
 796 static state_t
 797 f_runcom(void)
 798 {
 799         pid_t pid, wpid;
 800         int status;
 801         const char *argv[4];
 802         struct sigaction sa;
 803
 804         if ((pid = fork()) == 0) {
 805                 sigemptyset(&sa.sa_mask);
 806                 sa.sa_flags = 0;
 807                 sa.sa_handler = SIG_IGN;
 808                 sigaction(SIGTSTP, &sa, NULL);
 809                 sigaction(SIGHUP, &sa, NULL);
 810
 811                 setctty(_PATH_CONSOLE);
 812
 813                 argv[0] = "sh";
 814                 argv[1] = _PATH_RUNCOM;
 815                 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
 816                 argv[3] = NULL;
 817
 818                 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
 819
 820 #ifdef LOGIN_CAP
 821                 setprocresources(RESOURCE_RC);
 822 #endif
 823                 execv(_PATH_BSHELL, __DECONST(char **, argv));
 824                 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
 825                 _exit(1);       /* force single user mode */
 826         }
 827
 828         if (pid == -1) {
 829                 emergency("can't fork for %s on %s: %m",
 830                         _PATH_BSHELL, _PATH_RUNCOM);
 831                 while (waitpid(-1, NULL, WNOHANG) > 0)
 832                         continue;
 833                 sleep(STALL_TIMEOUT);
 834                 return single_user;
 835         }
 836
 837         /*
 838          * Copied from single_user().  This is a bit paranoid.
 839          */
 840         requested_transition = 0;
 841         do {
 842                 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
 843                         collect_child(wpid);
 844                 if (wpid == -1) {
 845                         if (requested_transition == death)
 846                                 return death;
 847                         if (errno == EINTR)
 848                                 continue;
 849                         warning("wait for %s on %s failed: %m; going to single user mode",
 850                                 _PATH_BSHELL, _PATH_RUNCOM);
 851                         return single_user;
 852                 }
 853                 if (wpid == pid && WIFSTOPPED(status)) {
 854                         warning("init: %s on %s stopped, restarting\n",
 855                                 _PATH_BSHELL, _PATH_RUNCOM);
 856                         kill(pid, SIGCONT);
 857                         wpid = -1;
 858                 }
 859         } while (wpid != pid);
 860
 861         if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
 862             requested_transition == catatonia) {
 863                 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
 864                 sigset_t s;
 865
 866                 sigfillset(&s);
 867                 for (;;)
 868                         sigsuspend(&s);
 869         }
 870
 871         if (!WIFEXITED(status)) {
 872                 warning("%s on %s terminated abnormally, going to single user mode",
 873                         _PATH_BSHELL, _PATH_RUNCOM);
 874                 return single_user;
 875         }
 876
 877         if (WEXITSTATUS(status))
 878                 return single_user;
 879
 880         runcom_mode = AUTOBOOT;         /* the default */
 881 #ifdef SUPPORT_UTMPX
 882         logwtmpx("~", "reboot", "", 0, INIT_PROCESS);
 883 #endif
 884         logwtmp("~", "reboot", "");
 885         return read_ttys;
 886 }
 887
 888 /*
 889  * Open the session database.
 890  *
 891  * NB: We could pass in the size here; is it necessary?
 892  */
 893 static int
 894 start_session_db(void)
 895 {
 896         if (session_db && (*session_db->close)(session_db))
 897                 emergency("session database close: %s", strerror(errno));
 898         if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) {
 899                 emergency("session database open: %s", strerror(errno));
 900                 return (1);
 901         }
 902         return (0);
 903
 904 }
 905
 906 /*
 907  * Add a new login session.
 908  */
 909 static void
 910 add_session(session_t *sp)
 911 {
 912         DBT key;
 913         DBT data;
 914
 915         key.data = &sp->se_process;
 916         key.size = sizeof sp->se_process;
 917         data.data = &sp;
 918         data.size = sizeof sp;
 919
 920         if ((*session_db->put)(session_db, &key, &data, 0))
 921                 emergency("insert %d: %s", sp->se_process, strerror(errno));
 922 #ifdef SUPPORT_UTMPX
 923         session_utmpx(sp, 1);
 924 #endif
 925 }
 926
 927 /*
 928  * Delete an old login session.
 929  */
 930 static void
 931 del_session(session_t *sp)
 932 {
 933         DBT key;
 934
 935         key.data = &sp->se_process;
 936         key.size = sizeof sp->se_process;
 937
 938         if ((*session_db->del)(session_db, &key, 0))
 939                 emergency("delete %d: %s", sp->se_process, strerror(errno));
 940 #ifdef SUPPORT_UTMPX
 941         session_utmpx(sp, 0);
 942 #endif
 943 }
 944
 945 /*
 946  * Look up a login session by pid.
 947  */
 948 static session_t *
 949 find_session(pid_t pid)
 950 {
 951         DBT key;
 952         DBT data;
 953         session_t *ret;
 954
 955         key.data = &pid;
 956         key.size = sizeof pid;
 957         if ((*session_db->get)(session_db, &key, &data, 0) != 0)
 958                 return 0;
 959         bcopy(data.data, (char *)&ret, sizeof(ret));
 960         return ret;
 961 }
 962
 963 /*
 964  * Construct an argument vector from a command line.
 965  */
 966 static char **
 967 construct_argv(char *command)
 968 {
 969         int argc = 0;
 970         char **argv = malloc(((strlen(command) + 1) / 2 + 1)
 971                                                 * sizeof (char *));
 972
 973         if ((argv[argc++] = strk(command)) == NULL) {
 974                 free(argv);
 975                 return (NULL);
 976         }
 977         while ((argv[argc++] = strk(NULL)) != NULL)
 978                 continue;
 979         return argv;
 980 }
 981
 982 /*
 983  * Deallocate a session descriptor.
 984  */
 985 static void
 986 free_session(session_t *sp)
 987 {
 988         free(sp->se_device);
 989         if (sp->se_getty) {
 990                 free(sp->se_getty);
 991                 free(sp->se_getty_argv_space);
 992                 free(sp->se_getty_argv);
 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         if (sp->se_type)
1000                 free(sp->se_type);
1001         free(sp);
1002 }
1003
1004 static
1005 void
1006 adjttyent(struct ttyent *typ)
1007 {
1008         struct stat st;
1009         uint32_t rdev;
1010         char *devpath;
1011         size_t rdev_size = sizeof(rdev);
1012
1013         if (typ->ty_name == NULL)
1014                 return;
1015
1016         /*
1017          * IFCONSOLE option forces tty off if not the console.
1018          */
1019         if (typ->ty_status & TTY_IFCONSOLE) {
1020                 asprintf(&devpath, "%s%s", _PATH_DEV, typ->ty_name);
1021                 if (stat(devpath, &st) < 0 ||
1022                     sysctlbyname("kern.console_rdev",
1023                                  &rdev, &rdev_size,
1024                                  NULL, 0) < 0) {
1025                         /* device does not exist or no sysctl, disable */
1026                         typ->ty_status &= ~TTY_ON;
1027                 } else if (rdev != st.st_rdev) {
1028                         typ->ty_status &= ~TTY_ON;
1029                 }
1030                 free(devpath);
1031         }
1032 }
1033
1034 /*
1035  * Allocate a new session descriptor.
1036  * Mark it SE_PRESENT.
1037  */
1038 static session_t *
1039 new_session(session_t *sprev, int session_index, struct ttyent *typ)
1040 {
1041         session_t *sp;
1042         int fd;
1043
1044         if (typ->ty_name == NULL || typ->ty_getty == NULL)
1045                 return 0;
1046
1047         if ((typ->ty_status & TTY_ON) == 0)
1048                 return 0;
1049
1050         sp = (session_t *) calloc(1, sizeof (session_t));
1051
1052         asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
1053         sp->se_index = session_index;
1054         sp->se_flags |= SE_PRESENT;
1055
1056         /*
1057          * Attempt to open the device, if we get "device not configured"
1058          * then don't add the device to the session list.
1059          */
1060         if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
1061                 if (errno == ENXIO) {
1062                         free_session(sp);
1063                         return (0);
1064                 }
1065         } else
1066                 close(fd);
1067
1068         if (setupargv(sp, typ) == 0) {
1069                 free_session(sp);
1070                 return (0);
1071         }
1072
1073         sp->se_next = NULL;
1074         if (sprev == NULL) {
1075                 sessions = sp;
1076                 sp->se_prev = NULL;
1077         } else {
1078                 sprev->se_next = sp;
1079                 sp->se_prev = sprev;
1080         }
1081
1082         return sp;
1083 }
1084
1085 /*
1086  * Calculate getty and if useful window argv vectors.
1087  */
1088 static int
1089 setupargv(session_t *sp, struct ttyent *typ)
1090 {
1091
1092         if (sp->se_getty) {
1093                 free(sp->se_getty);
1094                 free(sp->se_getty_argv_space);
1095                 free(sp->se_getty_argv);
1096         }
1097         sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1098         sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1099         sp->se_getty_argv_space = strdup(sp->se_getty);
1100         sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1101         if (sp->se_getty_argv == NULL) {
1102                 warning("can't parse getty for port %s", sp->se_device);
1103                 free(sp->se_getty);
1104                 free(sp->se_getty_argv_space);
1105                 sp->se_getty = sp->se_getty_argv_space = NULL;
1106                 return (0);
1107         }
1108         if (sp->se_window) {
1109                 free(sp->se_window);
1110                 free(sp->se_window_argv_space);
1111                 free(sp->se_window_argv);
1112         }
1113         sp->se_window = sp->se_window_argv_space = NULL;
1114         sp->se_window_argv = NULL;
1115         if (typ->ty_window) {
1116                 sp->se_window = strdup(typ->ty_window);
1117                 sp->se_window_argv_space = strdup(sp->se_window);
1118                 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1119                 if (sp->se_window_argv == NULL) {
1120                         warning("can't parse window for port %s",
1121                                 sp->se_device);
1122                         free(sp->se_window_argv_space);
1123                         free(sp->se_window);
1124                         sp->se_window = sp->se_window_argv_space = NULL;
1125                         return (0);
1126                 }
1127         }
1128         if (sp->se_type)
1129                 free(sp->se_type);
1130         sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1131         return (1);
1132 }
1133
1134 /*
1135  * Walk the list of ttys and create sessions for each active line.
1136  */
1137 static state_t
1138 f_read_ttys(void)
1139 {
1140         int session_index = 0;
1141         session_t *sp, *snext;
1142         struct ttyent *typ;
1143
1144 #ifdef SUPPORT_UTMPX
1145         if (sessions == NULL) {
1146                 struct stat st;
1147
1148                 make_utmpx("", BOOT_MSG, BOOT_TIME, 0, &boot_time, 0);
1149
1150                 /*
1151                  * If wtmpx is not empty, pick the down time from there
1152                  */
1153                 if (stat(_PATH_WTMPX, &st) != -1 && st.st_size != 0) {
1154                         struct timeval down_time;
1155
1156                         TIMESPEC_TO_TIMEVAL(&down_time,
1157                             st.st_atime > st.st_mtime ?
1158                             &st.st_atimespec : &st.st_mtimespec);
1159                         make_utmpx("", DOWN_MSG, DOWN_TIME, 0, &down_time, 0);
1160                 }
1161         }
1162 #endif
1163         /*
1164          * Destroy any previous session state.
1165          * There shouldn't be any, but just in case...
1166          */
1167         for (sp = sessions; sp; sp = snext) {
1168                 if (sp->se_process)
1169                         clear_session_logs(sp);
1170                 snext = sp->se_next;
1171                 free_session(sp);
1172         }
1173         sessions = NULL;
1174         if (start_session_db())
1175                 return single_user;
1176
1177         /*
1178          * Allocate a session entry for each active port.
1179          * Note that sp starts at 0.
1180          */
1181         while ((typ = getttyent()) != NULL) {
1182                 adjttyent(typ);
1183                 if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1184                         sp = snext;
1185         }
1186
1187         endttyent();
1188
1189         return multi_user;
1190 }
1191
1192 /*
1193  * Start a window system running.
1194  */
1195 static void
1196 start_window_system(session_t *sp)
1197 {
1198         pid_t pid;
1199         sigset_t mask;
1200         char term[64], *env[2];
1201
1202         if ((pid = fork()) == -1) {
1203                 emergency("can't fork for window system on port %s: %m",
1204                         sp->se_device);
1205                 /* hope that getty fails and we can try again */
1206                 return;
1207         }
1208
1209         if (pid)
1210                 return;
1211
1212         sigemptyset(&mask);
1213         sigprocmask(SIG_SETMASK, &mask, NULL);
1214
1215         if (setsid() < 0)
1216                 emergency("setsid failed (window) %m");
1217
1218 #ifdef LOGIN_CAP
1219         setprocresources(RESOURCE_WINDOW);
1220 #endif
1221         if (sp->se_type) {
1222                 /* Don't use malloc after fork */
1223                 strcpy(term, "TERM=");
1224                 strncat(term, sp->se_type, sizeof(term) - 6);
1225                 env[0] = term;
1226                 env[1] = NULL;
1227         }
1228         else
1229                 env[0] = NULL;
1230         execve(sp->se_window_argv[0], sp->se_window_argv, env);
1231         stall("can't exec window system '%s' for port %s: %m",
1232                 sp->se_window_argv[0], sp->se_device);
1233         _exit(1);
1234 }
1235
1236 /*
1237  * Start a login session running.
1238  */
1239 static pid_t
1240 start_getty(session_t *sp)
1241 {
1242         pid_t pid;
1243         sigset_t mask;
1244         time_t current_time = time(NULL);
1245         int too_quick = 0;
1246         char term[64], *env[2];
1247
1248         if (current_time >= sp->se_started.tv_sec &&
1249             current_time - sp->se_started.tv_sec < GETTY_SPACING) {
1250                 if (++sp->se_nspace > GETTY_NSPACE) {
1251                         sp->se_nspace = 0;
1252                         too_quick = 1;
1253                 }
1254         } else
1255                 sp->se_nspace = 0;
1256
1257         /*
1258          * fork(), not vfork() -- we can't afford to block.
1259          */
1260         if ((pid = fork()) == -1) {
1261                 emergency("can't fork for getty on port %s: %m", sp->se_device);
1262                 return -1;
1263         }
1264
1265         if (pid)
1266                 return pid;
1267
1268         if (too_quick) {
1269                 warning("getty repeating too quickly on port %s, sleeping %d secs",
1270                         sp->se_device, GETTY_SLEEP);
1271                 sleep((unsigned) GETTY_SLEEP);
1272         }
1273
1274         if (sp->se_window) {
1275                 start_window_system(sp);
1276                 sleep(WINDOW_WAIT);
1277         }
1278
1279         sigemptyset(&mask);
1280         sigprocmask(SIG_SETMASK, &mask, NULL);
1281
1282 #ifdef LOGIN_CAP
1283         setprocresources(RESOURCE_GETTY);
1284 #endif
1285         if (sp->se_type) {
1286                 /* Don't use malloc after fork */
1287                 strcpy(term, "TERM=");
1288                 strncat(term, sp->se_type, sizeof(term) - 6);
1289                 env[0] = term;
1290                 env[1] = NULL;
1291         }
1292         else
1293                 env[0] = NULL;
1294         execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1295         stall("can't exec getty '%s' for port %s: %m",
1296                 sp->se_getty_argv[0], sp->se_device);
1297         _exit(1);
1298 }
1299
1300 /*
1301  * Collect exit status for a child.
1302  * If an exiting login, start a new login running.
1303  */
1304 static void
1305 collect_child(pid_t pid)
1306 {
1307         session_t *sp, *sprev, *snext;
1308
1309         if (! sessions)
1310                 return;
1311
1312         if (! (sp = find_session(pid)))
1313                 return;
1314
1315         clear_session_logs(sp);
1316         del_session(sp);
1317         sp->se_process = 0;
1318
1319         if (sp->se_flags & SE_SHUTDOWN) {
1320                 if ((sprev = sp->se_prev) != NULL)
1321                         sprev->se_next = sp->se_next;
1322                 else
1323                         sessions = sp->se_next;
1324                 if ((snext = sp->se_next) != NULL)
1325                         snext->se_prev = sp->se_prev;
1326                 free_session(sp);
1327                 return;
1328         }
1329
1330         if ((pid = start_getty(sp)) == -1) {
1331                 /* serious trouble */
1332                 requested_transition = clean_ttys;
1333                 return;
1334         }
1335
1336         sp->se_process = pid;
1337         gettimeofday(&sp->se_started, NULL);
1338         add_session(sp);
1339 }
1340
1341 /*
1342  * Catch a signal and request a state transition.
1343  */
1344 static void
1345 transition_handler(int sig)
1346 {
1347
1348         switch (sig) {
1349         case SIGHUP:
1350                 requested_transition = clean_ttys;
1351                 break;
1352         case SIGUSR2:
1353                 howto = RB_POWEROFF;
1354                 /* FALLTHROUGH */
1355         case SIGUSR1:
1356                 howto |= RB_HALT;
1357                 /* FALLTHROUGH */
1358         case SIGINT:
1359                 Reboot = TRUE;
1360                 /* FALLTHROUGH */
1361         case SIGTERM:
1362                 requested_transition = death;
1363                 break;
1364         case SIGTSTP:
1365                 requested_transition = catatonia;
1366                 break;
1367         default:
1368                 requested_transition = 0;
1369                 break;
1370         }
1371 }
1372
1373 /*
1374  * Take the system multiuser.
1375  */
1376 static state_t
1377 f_multi_user(void)
1378 {
1379         pid_t pid;
1380         session_t *sp;
1381
1382         requested_transition = 0;
1383
1384         /*
1385          * If the administrator has not set the security level to -1
1386          * to indicate that the kernel should not run multiuser in secure
1387          * mode, and the run script has not set a higher level of security
1388          * than level 1, then put the kernel into secure mode.
1389          */
1390         if (getsecuritylevel() == 0)
1391                 setsecuritylevel(1);
1392
1393         for (sp = sessions; sp; sp = sp->se_next) {
1394                 if (sp->se_process)
1395                         continue;
1396                 if ((pid = start_getty(sp)) == -1) {
1397                         /* serious trouble */
1398                         requested_transition = clean_ttys;
1399                         break;
1400                 }
1401                 sp->se_process = pid;
1402                 gettimeofday(&sp->se_started, NULL);
1403                 add_session(sp);
1404         }
1405
1406         while (!requested_transition)
1407                 if ((pid = waitpid(-1, NULL, 0)) != -1)
1408                         collect_child(pid);
1409
1410         return requested_transition;
1411 }
1412
1413 /*
1414  * This is an (n*2)+(n^2) algorithm.  We hope it isn't run often...
1415  */
1416 static state_t
1417 f_clean_ttys(void)
1418 {
1419         session_t *sp, *sprev;
1420         struct ttyent *typ;
1421         int session_index = 0;
1422         int devlen;
1423         char *old_getty, *old_window, *old_type;
1424
1425         if (! sessions)
1426                 return multi_user;
1427
1428         /*
1429          * mark all sessions for death, (!SE_PRESENT)
1430          * as we find or create new ones they'll be marked as keepers,
1431          * we'll later nuke all the ones not found in /etc/ttys
1432          */
1433         for (sp = sessions; sp != NULL; sp = sp->se_next)
1434                 sp->se_flags &= ~SE_PRESENT;
1435
1436         devlen = sizeof(_PATH_DEV) - 1;
1437         while ((typ = getttyent()) != NULL) {
1438                 ++session_index;
1439
1440                 adjttyent(typ);
1441                 for (sprev = NULL, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1442                         if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1443                                 break;
1444
1445                 if (sp) {
1446                         /* we want this one to live */
1447                         sp->se_flags |= SE_PRESENT;
1448                         if (sp->se_index != session_index) {
1449                                 warning("port %s changed utmp index from %d to %d",
1450                                        sp->se_device, sp->se_index,
1451                                        session_index);
1452                                 sp->se_index = session_index;
1453                         }
1454                         if ((typ->ty_status & TTY_ON) == 0 ||
1455                             typ->ty_getty == 0) {
1456                                 sp->se_flags |= SE_SHUTDOWN;
1457                                 kill(sp->se_process, SIGHUP);
1458                                 continue;
1459                         }
1460                         sp->se_flags &= ~SE_SHUTDOWN;
1461                         old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1462                         old_window = sp->se_window ? strdup(sp->se_window) : 0;
1463                         old_type = sp->se_type ? strdup(sp->se_type) : 0;
1464                         if (setupargv(sp, typ) == 0) {
1465                                 warning("can't parse getty for port %s",
1466                                         sp->se_device);
1467                                 sp->se_flags |= SE_SHUTDOWN;
1468                                 kill(sp->se_process, SIGHUP);
1469                         }
1470                         else if (   !old_getty
1471                                  || (!old_type && sp->se_type)
1472                                  || (old_type && !sp->se_type)
1473                                  || (!old_window && sp->se_window)
1474                                  || (old_window && !sp->se_window)
1475                                  || (strcmp(old_getty, sp->se_getty) != 0)
1476                                  || (old_window && strcmp(old_window, sp->se_window) != 0)
1477                                  || (old_type && strcmp(old_type, sp->se_type) != 0)
1478                                 ) {
1479                                 /* Don't set SE_SHUTDOWN here */
1480                                 sp->se_nspace = 0;
1481                                 sp->se_started.tv_sec = sp->se_started.tv_usec = 0;
1482                                 kill(sp->se_process, SIGHUP);
1483                         }
1484                         if (old_getty)
1485                                 free(old_getty);
1486                         if (old_window)
1487                                 free(old_window);
1488                         if (old_type)
1489                                 free(old_type);
1490                         continue;
1491                 }
1492
1493                 new_session(sprev, session_index, typ);
1494         }
1495
1496         endttyent();
1497
1498         /*
1499          * sweep through and kill all deleted sessions
1500          * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1501          */
1502         for (sp = sessions; sp != NULL; sp = sp->se_next) {
1503                 if ((sp->se_flags & SE_PRESENT) == 0) {
1504                         sp->se_flags |= SE_SHUTDOWN;
1505                         kill(sp->se_process, SIGHUP);
1506                 }
1507         }
1508
1509         return multi_user;
1510 }
1511
1512 /*
1513  * Block further logins.
1514  */
1515 static state_t
1516 f_catatonia(void)
1517 {
1518         session_t *sp;
1519
1520         for (sp = sessions; sp; sp = sp->se_next)
1521                 sp->se_flags |= SE_SHUTDOWN;
1522
1523         return multi_user;
1524 }
1525
1526 /*
1527  * Note SIGALRM.
1528  */
1529 static void
1530 alrm_handler(int sig __unused)
1531 {
1532         clang = 1;
1533 }
1534
1535 /*
1536  * Bring the system down to single user.
1537  */
1538 static state_t
1539 f_death(void)
1540 {
1541         session_t *sp;
1542         int i;
1543         pid_t pid;
1544         static const int death_sigs[2] = { SIGTERM, SIGKILL };
1545
1546 #ifdef SUPPORT_UTMPX
1547         logwtmpx("~", "shutdown", "", 0, INIT_PROCESS);
1548 #endif
1549         logwtmp("~", "shutdown", "");
1550
1551         for (sp = sessions; sp; sp = sp->se_next) {
1552                 sp->se_flags |= SE_SHUTDOWN;
1553                 kill(sp->se_process, SIGHUP);
1554         }
1555
1556         /* Try to run the rc.shutdown script within a period of time */
1557         runshutdown();
1558
1559         for (i = 0; i < 2; ++i) {
1560                 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1561                         return single_user;
1562
1563                 clang = 0;
1564                 alarm(DEATH_WATCH);
1565                 do
1566                         if ((pid = waitpid(-1, NULL, 0)) != -1)
1567                                 collect_child(pid);
1568                 while (clang == 0 && errno != ECHILD);
1569
1570                 if (errno == ECHILD)
1571                         return single_user;
1572         }
1573
1574         warning("some processes would not die; ps axl advised");
1575
1576         return single_user;
1577 }
1578
1579 /*
1580  * Run the system shutdown script.
1581  *
1582  * Exit codes:      XXX I should document more
1583  * -2       shutdown script terminated abnormally
1584  * -1       fatal error - can't run script
1585  * 0        good.
1586  * >0       some error (exit code)
1587  */
1588 static int
1589 runshutdown(void)
1590 {
1591         pid_t pid, wpid;
1592         int status;
1593         int shutdowntimeout;
1594         size_t len;
1595         const char *argv[4];
1596         struct sigaction sa;
1597         struct stat sb;
1598
1599         /*
1600          * rc.shutdown is optional, so to prevent any unnecessary
1601          * complaints from the shell we simply don't run it if the
1602          * file does not exist. If the stat() here fails for other
1603          * reasons, we'll let the shell complain.
1604          */
1605         if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1606                 return 0;
1607
1608         if ((pid = fork()) == 0) {
1609                 int     fd;
1610
1611                 /* Assume that init already grab console as ctty before */
1612
1613                 sigemptyset(&sa.sa_mask);
1614                 sa.sa_flags = 0;
1615                 sa.sa_handler = SIG_IGN;
1616                 sigaction(SIGTSTP, &sa, NULL);
1617                 sigaction(SIGHUP, &sa, NULL);
1618
1619                 if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1620                     warning("can't open %s: %m", _PATH_CONSOLE);
1621                 else {
1622                     dup2(fd, 0);
1623                     dup2(fd, 1);
1624                     dup2(fd, 2);
1625                     if (fd > 2)
1626                         close(fd);
1627                 }
1628
1629                 /*
1630                  * Run the shutdown script.
1631                  */
1632                 argv[0] = "sh";
1633                 argv[1] = _PATH_RUNDOWN;
1634                 if (Reboot)
1635                         argv[2] = "reboot";
1636                 else
1637                         argv[2] = "single";
1638                 argv[3] = NULL;
1639
1640                 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1641
1642 #ifdef LOGIN_CAP
1643                 setprocresources(RESOURCE_RC);
1644 #endif
1645                 execv(_PATH_BSHELL, __DECONST(char **, argv));
1646                 warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1647                 _exit(1);       /* force single user mode */
1648         }
1649
1650         if (pid == -1) {
1651                 emergency("can't fork for %s on %s: %m",
1652                         _PATH_BSHELL, _PATH_RUNDOWN);
1653                 while (waitpid(-1, NULL, WNOHANG) > 0)
1654                         continue;
1655                 sleep(STALL_TIMEOUT);
1656                 return -1;
1657         }
1658
1659         len = sizeof(shutdowntimeout);
1660         if (sysctlbyname("kern.init_shutdown_timeout",
1661                          &shutdowntimeout,
1662                          &len, NULL, 0) == -1 || shutdowntimeout < 2)
1663             shutdowntimeout = DEATH_SCRIPT;
1664         alarm(shutdowntimeout);
1665         clang = 0;
1666         /*
1667          * Copied from single_user().  This is a bit paranoid.
1668          * Use the same ALRM handler.
1669          */
1670         do {
1671                 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1672                         collect_child(wpid);
1673                 if (clang == 1) {
1674                         /* we were waiting for the sub-shell */
1675                         kill(wpid, SIGTERM);
1676                         warning("timeout expired for %s on %s: %m; going to single user mode",
1677                                 _PATH_BSHELL, _PATH_RUNDOWN);
1678                         return -1;
1679                 }
1680                 if (wpid == -1) {
1681                         if (errno == EINTR)
1682                                 continue;
1683                         warning("wait for %s on %s failed: %m; going to single user mode",
1684                                 _PATH_BSHELL, _PATH_RUNDOWN);
1685                         return -1;
1686                 }
1687                 if (wpid == pid && WIFSTOPPED(status)) {
1688                         warning("init: %s on %s stopped, restarting\n",
1689                                 _PATH_BSHELL, _PATH_RUNDOWN);
1690                         kill(pid, SIGCONT);
1691                         wpid = -1;
1692                 }
1693         } while (wpid != pid && !clang);
1694
1695         /* Turn off the alarm */
1696         alarm(0);
1697
1698         if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1699             requested_transition == catatonia) {
1700                 /*
1701                  * /etc/rc.shutdown executed /sbin/reboot;
1702                  * wait for the end quietly
1703                  */
1704                 sigset_t s;
1705
1706                 sigfillset(&s);
1707                 for (;;)
1708                         sigsuspend(&s);
1709         }
1710
1711         if (!WIFEXITED(status)) {
1712                 warning("%s on %s terminated abnormally, going to single user mode",
1713                         _PATH_BSHELL, _PATH_RUNDOWN);
1714                 return -2;
1715         }
1716
1717         if ((status = WEXITSTATUS(status)) != 0)
1718                 warning("%s returned status %d", _PATH_RUNDOWN, status);
1719
1720         return status;
1721 }
1722
1723 static char *
1724 strk(char *p)
1725 {
1726     static char *t;
1727     char *q;
1728     int c;
1729
1730     if (p)
1731         t = p;
1732     if (!t)
1733         return 0;
1734
1735     c = *t;
1736     while (c == ' ' || c == '\t' )
1737         c = *++t;
1738     if (!c) {
1739         t = NULL;
1740         return 0;
1741     }
1742     q = t;
1743     if (c == '\'') {
1744         c = *++t;
1745         q = t;
1746         while (c && c != '\'')
1747             c = *++t;
1748         if (!c)  /* unterminated string */
1749             q = t = NULL;
1750         else
1751             *t++ = 0;
1752     } else {
1753         while (c && c != ' ' && c != '\t' )
1754             c = *++t;
1755         *t++ = 0;
1756         if (!c)
1757             t = NULL;
1758     }
1759     return q;
1760 }
1761
1762 #ifdef LOGIN_CAP
1763 static void
1764 setprocresources(const char *cname)
1765 {
1766         login_cap_t *lc;
1767         if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1768                 setusercontext(lc, NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1769                 login_close(lc);
1770         }
1771 }
1772 #endif
1773
1774 #ifdef SUPPORT_UTMPX
1775 static void
1776 session_utmpx(const session_t *sp, int add)
1777 {
1778         const char *name = sp->se_getty ? sp->se_getty :
1779             (sp->se_window ? sp->se_window : "");
1780         const char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
1781
1782         make_utmpx(name, line, add ? LOGIN_PROCESS : DEAD_PROCESS,
1783             sp->se_process, &sp->se_started, sp->se_index);
1784 }
1785
1786 static void
1787 make_utmpx(const char *name, const char *line, int type, pid_t pid,
1788     const struct timeval *tv, int session)
1789 {
1790         struct utmpx ut;
1791         const char *eline;
1792
1793         (void)memset(&ut, 0, sizeof(ut));
1794         (void)strlcpy(ut.ut_name, name, sizeof(ut.ut_name));
1795         ut.ut_type = type;
1796         (void)strlcpy(ut.ut_line, line, sizeof(ut.ut_line));
1797         ut.ut_pid = pid;
1798         if (tv)
1799                 ut.ut_tv = *tv;
1800         else
1801                 (void)gettimeofday(&ut.ut_tv, NULL);
1802         ut.ut_session = session;
1803
1804         eline = line + strlen(line);
1805         if ((size_t)(eline - line) >= sizeof(ut.ut_id))
1806                 line = eline - sizeof(ut.ut_id);
1807         (void)strncpy(ut.ut_id, line, sizeof(ut.ut_id));
1808
1809         if (pututxline(&ut) == NULL)
1810                 warning("can't add utmpx record for `%s': %m", ut.ut_line);
1811         endutxent();
1812 }
1813
1814 static char
1815 get_runlevel(const state_t s)
1816 {
1817         if (s == single_user)
1818                 return SINGLE_USER;
1819         if (s == runcom)
1820                 return RUNCOM;
1821         if (s == read_ttys)
1822                 return READ_TTYS;
1823         if (s == multi_user)
1824                 return MULTI_USER;
1825         if (s == clean_ttys)
1826                 return CLEAN_TTYS;
1827         if (s == catatonia)
1828                 return CATATONIA;
1829         return DEATH;
1830 }
1831
1832 static void
1833 utmpx_set_runlevel(char old, char new)
1834 {
1835         struct utmpx ut;
1836
1837         /*
1838          * Don't record any transitions until we did the first transition
1839          * to read ttys, which is when we are guaranteed to have a read-write
1840          * /var. Perhaps use a different variable for this?
1841          */
1842         if (sessions == NULL)
1843                 return;
1844
1845         (void)memset(&ut, 0, sizeof(ut));
1846         (void)snprintf(ut.ut_line, sizeof(ut.ut_line), RUNLVL_MSG, new);
1847         ut.ut_type = RUN_LVL;
1848         (void)gettimeofday(&ut.ut_tv, NULL);
1849         ut.ut_exit.e_exit = old;
1850         ut.ut_exit.e_termination = new;
1851         if (pututxline(&ut) == NULL)
1852                 warning("can't add utmpx record for `runlevel': %m");
1853         endutxent();
1854 }
1855 #endif