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  * NB: should send a message to the session logger to avoid blocking.
 416  */
 417 static void
 418 stall(const char *message, ...)
 419 {
 420         va_list ap;
 421
 422         va_start(ap, message);
 423
 424         vsyslog(LOG_ALERT, message, ap);
 425         va_end(ap);
 426         sleep(STALL_TIMEOUT);
 427 }
 428
 429 /*
 430  * Like stall(), but doesn't sleep.
 431  * If cpp had variadic macros, the two functions could be #defines for another.
 432  * NB: should send a message to the session logger to avoid blocking.
 433  */
 434 static void
 435 warning(const char *message, ...)
 436 {
 437         va_list ap;
 438
 439         va_start(ap, message);
 440
 441         vsyslog(LOG_ALERT, message, ap);
 442         va_end(ap);
 443 }
 444
 445 /*
 446  * Log an emergency message.
 447  * NB: should send a message to the session logger to avoid blocking.
 448  */
 449 static void
 450 emergency(const char *message, ...)
 451 {
 452         va_list ap;
 453
 454         va_start(ap, message);
 455
 456         vsyslog(LOG_EMERG, message, ap);
 457         va_end(ap);
 458 }
 459
 460 /*
 461  * Catch a SIGSYS signal.
 462  *
 463  * These may arise if a system does not support sysctl.
 464  * We tolerate up to 25 of these, then throw in the towel.
 465  */
 466 static void
 467 badsys(int sig)
 468 {
 469         static int badcount = 0;
 470
 471         if (badcount++ < 25)
 472                 return;
 473         disaster(sig);
 474 }
 475
 476 /*
 477  * Catch an unexpected signal.
 478  */
 479 static void
 480 disaster(int sig)
 481 {
 482         emergency("fatal signal: %s",
 483                 (unsigned)sig < NSIG ? sys_siglist[sig] : "unknown signal");
 484
 485         sleep(STALL_TIMEOUT);
 486         _exit(sig);             /* reboot */
 487 }
 488
 489 /*
 490  * Get the security level of the kernel.
 491  */
 492 static int
 493 getsecuritylevel(void)
 494 {
 495 #ifdef KERN_SECURELVL
 496         int name[2], curlevel;
 497         size_t len;
 498
 499         name[0] = CTL_KERN;
 500         name[1] = KERN_SECURELVL;
 501         len = sizeof curlevel;
 502         if (sysctl(name, 2, &curlevel, &len, NULL, 0) == -1) {
 503                 emergency("cannot get kernel security level: %s",
 504                     strerror(errno));
 505                 return (-1);
 506         }
 507         return (curlevel);
 508 #else
 509         return (-1);
 510 #endif
 511 }
 512
 513 /*
 514  * Get the value of the "init_chroot" variable from the
 515  * kernel environment (or NULL if not set).
 516  */
 517
 518 static char *
 519 get_chroot(void)
 520 {
 521         static const char ichname[] = "init_chroot=";   /* includes '=' */
 522         const int ichlen = strlen(ichname);
 523         int real_oid[CTL_MAXNAME];
 524         char sbuf[1024];
 525         size_t oidlen, slen;
 526         char *res;
 527         int i;
 528
 529         oidlen = NELEM(real_oid);
 530         if (sysctlnametomib("kern.environment", real_oid, &oidlen)) {
 531                 warning("cannot find kern.environment base sysctl OID");
 532                 return NULL;
 533         }
 534         if (oidlen + 1 >= NELEM(real_oid)) {
 535                 warning("kern.environment OID is too large!");
 536                 return NULL;
 537         }
 538         res = NULL;
 539         real_oid[oidlen] = 0;
 540
 541         for (i = 0; ; i++) {
 542                 real_oid[oidlen + 1] = i;
 543                 slen = sizeof(sbuf);
 544                 if (sysctl(real_oid, oidlen + 2, sbuf, &slen, NULL, 0) < 0) {
 545                         if (errno != ENOENT)
 546                                 warning("sysctl kern.environment.%d: %m", i);
 547                         break;
 548                 }
 549
 550                 /*
 551                  * slen includes the terminating \0, but do a few sanity
 552                  * checks anyway.
 553                  */
 554                 if (slen == 0)
 555                         continue;
 556                 sbuf[slen - 1] = 0;
 557                 if (strncmp(sbuf, ichname, ichlen) != 0)
 558                         continue;
 559                 if (sbuf[ichlen])
 560                         res = strdup(sbuf + ichlen);
 561                 break;
 562         }
 563         return (res);
 564 }
 565
 566 /*
 567  * Set the security level of the kernel.
 568  */
 569 static void
 570 setsecuritylevel(int newlevel)
 571 {
 572 #ifdef KERN_SECURELVL
 573         int name[2], curlevel;
 574
 575         curlevel = getsecuritylevel();
 576         if (newlevel == curlevel)
 577                 return;
 578         name[0] = CTL_KERN;
 579         name[1] = KERN_SECURELVL;
 580         if (sysctl(name, 2, NULL, NULL, &newlevel, sizeof newlevel) == -1) {
 581                 emergency(
 582                     "cannot change kernel security level from %d to %d: %s",
 583                     curlevel, newlevel, strerror(errno));
 584                 return;
 585         }
 586 #ifdef SECURE
 587         warning("kernel security level changed from %d to %d",
 588             curlevel, newlevel);
 589 #endif
 590 #endif
 591 }
 592
 593 /*
 594  * Change states in the finite state machine.
 595  * The initial state is passed as an argument.
 596  */
 597 static void
 598 transition(state_t s)
 599 {
 600         for (;;) {
 601 #ifdef SUPPORT_UTMPX
 602                 utmpx_set_runlevel(get_runlevel(current_state),
 603                     get_runlevel(s));
 604                 current_state = s;
 605 #endif
 606                 s = (*state_funcs[s])();
 607         }
 608 }
 609
 610 /*
 611  * Close out the accounting files for a login session.
 612  * NB: should send a message to the session logger to avoid blocking.
 613  */
 614 static void
 615 clear_session_logs(session_t *sp)
 616 {
 617         char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
 618
 619 #ifdef SUPPORT_UTMPX
 620         if (logoutx(line, 0, DEAD_PROCESS))
 621                  logwtmpx(line, "", "", 0, DEAD_PROCESS);
 622 #endif
 623         if (logout(line))
 624                 logwtmp(line, "", "");
 625 }
 626
 627 /*
 628  * Start a session and allocate a controlling terminal.
 629  * Only called by children of init after forking.
 630  */
 631 static void
 632 setctty(const char *name)
 633 {
 634         int fd;
 635
 636         revoke(name);
 637         if ((fd = open(name, O_RDWR)) == -1) {
 638                 stall("can't open %s: %m", name);
 639                 _exit(1);
 640         }
 641         if (login_tty(fd) == -1) {
 642                 stall("can't get %s for controlling terminal: %m", name);
 643                 _exit(1);
 644         }
 645 }
 646
 647 /*
 648  * Bring the system up single user.
 649  */
 650 static state_t
 651 f_single_user(void)
 652 {
 653         pid_t pid, wpid;
 654         int status;
 655         sigset_t mask;
 656         const char *shell = _PATH_BSHELL;
 657         const char *argv[2];
 658 #ifdef SECURE
 659         struct ttyent *typ;
 660         struct passwd *pp;
 661         static const char banner[] =
 662                 "Enter root password, or ^D to go multi-user\n";
 663         char *clear, *password;
 664 #endif
 665 #ifdef DEBUGSHELL
 666         char altshell[128];
 667 #endif
 668
 669         if (Reboot) {
 670                 /* Instead of going single user, let's reboot the machine */
 671                 sync();
 672                 alarm(2);
 673                 pause();
 674                 reboot(howto);
 675                 _exit(0);
 676         }
 677
 678         if ((pid = fork()) == 0) {
 679                 /*
 680                  * Start the single user session.
 681                  */
 682                 setctty(_PATH_CONSOLE);
 683
 684 #ifdef SECURE
 685                 /*
 686                  * Check the root password.
 687                  * We don't care if the console is 'on' by default;
 688                  * it's the only tty that can be 'off' and 'secure'.
 689                  */
 690                 typ = getttynam("console");
 691                 pp = getpwnam("root");
 692                 if (typ && (typ->ty_status & TTY_SECURE) == 0 &&
 693                     pp && *pp->pw_passwd) {
 694                         write(2, banner, sizeof banner - 1);
 695                         for (;;) {
 696                                 clear = getpass("Password:");
 697                                 if (clear == NULL || *clear == '\0')
 698                                         _exit(0);
 699                                 password = crypt(clear, pp->pw_passwd);
 700                                 bzero(clear, _PASSWORD_LEN);
 701                                 if (password != NULL && strcmp(password, pp->pw_passwd) == 0)
 702                                         break;
 703                                 warning("single-user login failed\n");
 704                         }
 705                 }
 706                 endttyent();
 707                 endpwent();
 708 #endif /* SECURE */
 709
 710 #ifdef DEBUGSHELL
 711                 {
 712                         char *cp = altshell;
 713                         int num;
 714
 715 #define SHREQUEST \
 716         "Enter full pathname of shell or RETURN for " _PATH_BSHELL ": "
 717                         write(STDERR_FILENO, SHREQUEST, sizeof(SHREQUEST) - 1);
 718                         while ((num = read(STDIN_FILENO, cp, 1)) != -1 &&
 719                             num != 0 && *cp != '\n' && cp < &altshell[127])
 720                                         cp++;
 721                         *cp = '\0';
 722                         if (altshell[0] != '\0')
 723                                 shell = altshell;
 724                 }
 725 #endif /* DEBUGSHELL */
 726
 727                 /*
 728                  * Unblock signals.
 729                  * We catch all the interesting ones,
 730                  * and those are reset to SIG_DFL on exec.
 731                  */
 732                 sigemptyset(&mask);
 733                 sigprocmask(SIG_SETMASK, &mask, NULL);
 734
 735                 /*
 736                  * Fire off a shell.
 737                  * If the default one doesn't work, try the Bourne shell.
 738                  */
 739                 argv[0] = "-sh";
 740                 argv[1] = NULL;
 741                 execv(shell, __DECONST(char **, argv));
 742                 emergency("can't exec %s for single user: %m", shell);
 743                 execv(_PATH_BSHELL, __DECONST(char **, argv));
 744                 emergency("can't exec %s for single user: %m", _PATH_BSHELL);
 745                 sleep(STALL_TIMEOUT);
 746                 _exit(1);
 747         }
 748
 749         if (pid == -1) {
 750                 /*
 751                  * We are seriously hosed.  Do our best.
 752                  */
 753                 emergency("can't fork single-user shell, trying again");
 754                 while (waitpid(-1, NULL, WNOHANG) > 0)
 755                         continue;
 756                 return single_user;
 757         }
 758
 759         requested_transition = 0;
 760         do {
 761                 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
 762                         collect_child(wpid);
 763                 if (wpid == -1) {
 764                         if (errno == EINTR)
 765                                 continue;
 766                         warning("wait for single-user shell failed: %m; restarting");
 767                         return single_user;
 768                 }
 769                 if (wpid == pid && WIFSTOPPED(status)) {
 770                         warning("init: shell stopped, restarting\n");
 771                         kill(pid, SIGCONT);
 772                         wpid = -1;
 773                 }
 774         } while (wpid != pid && !requested_transition);
 775
 776         if (requested_transition)
 777                 return requested_transition;
 778
 779         if (!WIFEXITED(status)) {
 780                 if (WTERMSIG(status) == SIGKILL) {
 781                         /*
 782                          *  reboot(8) killed shell?
 783                          */
 784                         warning("single user shell terminated.");
 785                         sleep(STALL_TIMEOUT);
 786                         _exit(0);
 787                 } else {
 788                         warning("single user shell terminated, restarting");
 789                         return single_user;
 790                 }
 791         }
 792
 793         runcom_mode = FASTBOOT;
 794         return runcom;
 795 }
 796
 797 /*
 798  * Run the system startup script.
 799  */
 800 static state_t
 801 f_runcom(void)
 802 {
 803         pid_t pid, wpid;
 804         int status;
 805         const char *argv[4];
 806         struct sigaction sa;
 807
 808         if ((pid = fork()) == 0) {
 809                 sigemptyset(&sa.sa_mask);
 810                 sa.sa_flags = 0;
 811                 sa.sa_handler = SIG_IGN;
 812                 sigaction(SIGTSTP, &sa, NULL);
 813                 sigaction(SIGHUP, &sa, NULL);
 814
 815                 setctty(_PATH_CONSOLE);
 816
 817                 argv[0] = "sh";
 818                 argv[1] = _PATH_RUNCOM;
 819                 argv[2] = runcom_mode == AUTOBOOT ? "autoboot" : 0;
 820                 argv[3] = NULL;
 821
 822                 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
 823
 824 #ifdef LOGIN_CAP
 825                 setprocresources(RESOURCE_RC);
 826 #endif
 827                 execv(_PATH_BSHELL, __DECONST(char **, argv));
 828                 stall("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNCOM);
 829                 _exit(1);       /* force single user mode */
 830         }
 831
 832         if (pid == -1) {
 833                 emergency("can't fork for %s on %s: %m",
 834                         _PATH_BSHELL, _PATH_RUNCOM);
 835                 while (waitpid(-1, NULL, WNOHANG) > 0)
 836                         continue;
 837                 sleep(STALL_TIMEOUT);
 838                 return single_user;
 839         }
 840
 841         /*
 842          * Copied from single_user().  This is a bit paranoid.
 843          */
 844         requested_transition = 0;
 845         do {
 846                 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
 847                         collect_child(wpid);
 848                 if (wpid == -1) {
 849                         if (requested_transition == death)
 850                                 return death;
 851                         if (errno == EINTR)
 852                                 continue;
 853                         warning("wait for %s on %s failed: %m; going to single user mode",
 854                                 _PATH_BSHELL, _PATH_RUNCOM);
 855                         return single_user;
 856                 }
 857                 if (wpid == pid && WIFSTOPPED(status)) {
 858                         warning("init: %s on %s stopped, restarting\n",
 859                                 _PATH_BSHELL, _PATH_RUNCOM);
 860                         kill(pid, SIGCONT);
 861                         wpid = -1;
 862                 }
 863         } while (wpid != pid);
 864
 865         if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
 866             requested_transition == catatonia) {
 867                 /* /etc/rc executed /sbin/reboot; wait for the end quietly */
 868                 sigset_t s;
 869
 870                 sigfillset(&s);
 871                 for (;;)
 872                         sigsuspend(&s);
 873         }
 874
 875         if (!WIFEXITED(status)) {
 876                 warning("%s on %s terminated abnormally, going to single user mode",
 877                         _PATH_BSHELL, _PATH_RUNCOM);
 878                 return single_user;
 879         }
 880
 881         if (WEXITSTATUS(status))
 882                 return single_user;
 883
 884         runcom_mode = AUTOBOOT;         /* the default */
 885         /* NB: should send a message to the session logger to avoid blocking. */
 886 #ifdef SUPPORT_UTMPX
 887         logwtmpx("~", "reboot", "", 0, INIT_PROCESS);
 888 #endif
 889         logwtmp("~", "reboot", "");
 890         return read_ttys;
 891 }
 892
 893 /*
 894  * Open the session database.
 895  *
 896  * NB: We could pass in the size here; is it necessary?
 897  */
 898 static int
 899 start_session_db(void)
 900 {
 901         if (session_db && (*session_db->close)(session_db))
 902                 emergency("session database close: %s", strerror(errno));
 903         if ((session_db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) {
 904                 emergency("session database open: %s", strerror(errno));
 905                 return (1);
 906         }
 907         return (0);
 908
 909 }
 910
 911 /*
 912  * Add a new login session.
 913  */
 914 static void
 915 add_session(session_t *sp)
 916 {
 917         DBT key;
 918         DBT data;
 919
 920         key.data = &sp->se_process;
 921         key.size = sizeof sp->se_process;
 922         data.data = &sp;
 923         data.size = sizeof sp;
 924
 925         if ((*session_db->put)(session_db, &key, &data, 0))
 926                 emergency("insert %d: %s", sp->se_process, strerror(errno));
 927 #ifdef SUPPORT_UTMPX
 928         session_utmpx(sp, 1);
 929 #endif
 930 }
 931
 932 /*
 933  * Delete an old login session.
 934  */
 935 static void
 936 del_session(session_t *sp)
 937 {
 938         DBT key;
 939
 940         key.data = &sp->se_process;
 941         key.size = sizeof sp->se_process;
 942
 943         if ((*session_db->del)(session_db, &key, 0))
 944                 emergency("delete %d: %s", sp->se_process, strerror(errno));
 945 #ifdef SUPPORT_UTMPX
 946         session_utmpx(sp, 0);
 947 #endif
 948 }
 949
 950 /*
 951  * Look up a login session by pid.
 952  */
 953 static session_t *
 954 find_session(pid_t pid)
 955 {
 956         DBT key;
 957         DBT data;
 958         session_t *ret;
 959
 960         key.data = &pid;
 961         key.size = sizeof pid;
 962         if ((*session_db->get)(session_db, &key, &data, 0) != 0)
 963                 return 0;
 964         bcopy(data.data, (char *)&ret, sizeof(ret));
 965         return ret;
 966 }
 967
 968 /*
 969  * Construct an argument vector from a command line.
 970  */
 971 static char **
 972 construct_argv(char *command)
 973 {
 974         int argc = 0;
 975         char **argv = malloc(((strlen(command) + 1) / 2 + 1)
 976                                                 * sizeof (char *));
 977
 978         if ((argv[argc++] = strk(command)) == NULL) {
 979                 free(argv);
 980                 return (NULL);
 981         }
 982         while ((argv[argc++] = strk(NULL)) != NULL)
 983                 continue;
 984         return argv;
 985 }
 986
 987 /*
 988  * Deallocate a session descriptor.
 989  */
 990 static void
 991 free_session(session_t *sp)
 992 {
 993         free(sp->se_device);
 994         if (sp->se_getty) {
 995                 free(sp->se_getty);
 996                 free(sp->se_getty_argv_space);
 997                 free(sp->se_getty_argv);
 998         }
 999         if (sp->se_window) {
1000                 free(sp->se_window);
1001                 free(sp->se_window_argv_space);
1002                 free(sp->se_window_argv);
1003         }
1004         if (sp->se_type)
1005                 free(sp->se_type);
1006         free(sp);
1007 }
1008
1009 static
1010 void
1011 adjttyent(struct ttyent *typ)
1012 {
1013         struct stat st;
1014         uint32_t rdev;
1015         char *devpath;
1016         size_t rdev_size = sizeof(rdev);
1017
1018         if (typ->ty_name == NULL)
1019                 return;
1020
1021         /*
1022          * IFCONSOLE option forces tty off if not the console.
1023          */
1024         if (typ->ty_status & TTY_IFCONSOLE) {
1025                 asprintf(&devpath, "%s%s", _PATH_DEV, typ->ty_name);
1026                 if (stat(devpath, &st) < 0 ||
1027                     sysctlbyname("kern.console_rdev",
1028                                  &rdev, &rdev_size,
1029                                  NULL, 0) < 0) {
1030                         /* device does not exist or no sysctl, disable */
1031                         typ->ty_status &= ~TTY_ON;
1032                 } else if (rdev != st.st_rdev) {
1033                         typ->ty_status &= ~TTY_ON;
1034                 }
1035                 free(devpath);
1036         }
1037 }
1038
1039 /*
1040  * Allocate a new session descriptor.
1041  * Mark it SE_PRESENT.
1042  */
1043 static session_t *
1044 new_session(session_t *sprev, int session_index, struct ttyent *typ)
1045 {
1046         session_t *sp;
1047         int fd;
1048
1049         if (typ->ty_name == NULL || typ->ty_getty == NULL)
1050                 return 0;
1051
1052         if ((typ->ty_status & TTY_ON) == 0)
1053                 return 0;
1054
1055         sp = (session_t *) calloc(1, sizeof (session_t));
1056
1057         asprintf(&sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
1058         sp->se_index = session_index;
1059         sp->se_flags |= SE_PRESENT;
1060
1061         /*
1062          * Attempt to open the device, if we get "device not configured"
1063          * then don't add the device to the session list.
1064          */
1065         if ((fd = open(sp->se_device, O_RDONLY | O_NONBLOCK, 0)) < 0) {
1066                 if (errno == ENXIO) {
1067                         free_session(sp);
1068                         return (0);
1069                 }
1070         } else
1071                 close(fd);
1072
1073         if (setupargv(sp, typ) == 0) {
1074                 free_session(sp);
1075                 return (0);
1076         }
1077
1078         sp->se_next = NULL;
1079         if (sprev == NULL) {
1080                 sessions = sp;
1081                 sp->se_prev = NULL;
1082         } else {
1083                 sprev->se_next = sp;
1084                 sp->se_prev = sprev;
1085         }
1086
1087         return sp;
1088 }
1089
1090 /*
1091  * Calculate getty and if useful window argv vectors.
1092  */
1093 static int
1094 setupargv(session_t *sp, struct ttyent *typ)
1095 {
1096
1097         if (sp->se_getty) {
1098                 free(sp->se_getty);
1099                 free(sp->se_getty_argv_space);
1100                 free(sp->se_getty_argv);
1101         }
1102         sp->se_getty = malloc(strlen(typ->ty_getty) + strlen(typ->ty_name) + 2);
1103         sprintf(sp->se_getty, "%s %s", typ->ty_getty, typ->ty_name);
1104         sp->se_getty_argv_space = strdup(sp->se_getty);
1105         sp->se_getty_argv = construct_argv(sp->se_getty_argv_space);
1106         if (sp->se_getty_argv == NULL) {
1107                 warning("can't parse getty for port %s", sp->se_device);
1108                 free(sp->se_getty);
1109                 free(sp->se_getty_argv_space);
1110                 sp->se_getty = sp->se_getty_argv_space = NULL;
1111                 return (0);
1112         }
1113         if (sp->se_window) {
1114                 free(sp->se_window);
1115                 free(sp->se_window_argv_space);
1116                 free(sp->se_window_argv);
1117         }
1118         sp->se_window = sp->se_window_argv_space = NULL;
1119         sp->se_window_argv = NULL;
1120         if (typ->ty_window) {
1121                 sp->se_window = strdup(typ->ty_window);
1122                 sp->se_window_argv_space = strdup(sp->se_window);
1123                 sp->se_window_argv = construct_argv(sp->se_window_argv_space);
1124                 if (sp->se_window_argv == NULL) {
1125                         warning("can't parse window for port %s",
1126                                 sp->se_device);
1127                         free(sp->se_window_argv_space);
1128                         free(sp->se_window);
1129                         sp->se_window = sp->se_window_argv_space = NULL;
1130                         return (0);
1131                 }
1132         }
1133         if (sp->se_type)
1134                 free(sp->se_type);
1135         sp->se_type = typ->ty_type ? strdup(typ->ty_type) : 0;
1136         return (1);
1137 }
1138
1139 /*
1140  * Walk the list of ttys and create sessions for each active line.
1141  */
1142 static state_t
1143 f_read_ttys(void)
1144 {
1145         int session_index = 0;
1146         session_t *sp, *snext;
1147         struct ttyent *typ;
1148
1149 #ifdef SUPPORT_UTMPX
1150         if (sessions == NULL) {
1151                 struct stat st;
1152
1153                 make_utmpx("", BOOT_MSG, BOOT_TIME, 0, &boot_time, 0);
1154
1155                 /*
1156                  * If wtmpx is not empty, pick the down time from there
1157                  */
1158                 if (stat(_PATH_WTMPX, &st) != -1 && st.st_size != 0) {
1159                         struct timeval down_time;
1160
1161                         TIMESPEC_TO_TIMEVAL(&down_time,
1162                             st.st_atime > st.st_mtime ?
1163                             &st.st_atimespec : &st.st_mtimespec);
1164                         make_utmpx("", DOWN_MSG, DOWN_TIME, 0, &down_time, 0);
1165                 }
1166         }
1167 #endif
1168         /*
1169          * Destroy any previous session state.
1170          * There shouldn't be any, but just in case...
1171          */
1172         for (sp = sessions; sp; sp = snext) {
1173                 if (sp->se_process)
1174                         clear_session_logs(sp);
1175                 snext = sp->se_next;
1176                 free_session(sp);
1177         }
1178         sessions = NULL;
1179         if (start_session_db())
1180                 return single_user;
1181
1182         /*
1183          * Allocate a session entry for each active port.
1184          * Note that sp starts at 0.
1185          */
1186         while ((typ = getttyent()) != NULL) {
1187                 adjttyent(typ);
1188                 if ((snext = new_session(sp, ++session_index, typ)) != NULL)
1189                         sp = snext;
1190         }
1191
1192         endttyent();
1193
1194         return multi_user;
1195 }
1196
1197 /*
1198  * Start a window system running.
1199  */
1200 static void
1201 start_window_system(session_t *sp)
1202 {
1203         pid_t pid;
1204         sigset_t mask;
1205         char term[64], *env[2];
1206
1207         if ((pid = fork()) == -1) {
1208                 emergency("can't fork for window system on port %s: %m",
1209                         sp->se_device);
1210                 /* hope that getty fails and we can try again */
1211                 return;
1212         }
1213
1214         if (pid)
1215                 return;
1216
1217         sigemptyset(&mask);
1218         sigprocmask(SIG_SETMASK, &mask, NULL);
1219
1220         if (setsid() < 0)
1221                 emergency("setsid failed (window) %m");
1222
1223 #ifdef LOGIN_CAP
1224         setprocresources(RESOURCE_WINDOW);
1225 #endif
1226         if (sp->se_type) {
1227                 /* Don't use malloc after fork */
1228                 strcpy(term, "TERM=");
1229                 strncat(term, sp->se_type, sizeof(term) - 6);
1230                 env[0] = term;
1231                 env[1] = NULL;
1232         }
1233         else
1234                 env[0] = NULL;
1235         execve(sp->se_window_argv[0], sp->se_window_argv, env);
1236         stall("can't exec window system '%s' for port %s: %m",
1237                 sp->se_window_argv[0], sp->se_device);
1238         _exit(1);
1239 }
1240
1241 /*
1242  * Start a login session running.
1243  */
1244 static pid_t
1245 start_getty(session_t *sp)
1246 {
1247         pid_t pid;
1248         sigset_t mask;
1249         time_t current_time = time(NULL);
1250         int too_quick = 0;
1251         char term[64], *env[2];
1252
1253         if (current_time >= sp->se_started.tv_sec &&
1254             current_time - sp->se_started.tv_sec < GETTY_SPACING) {
1255                 if (++sp->se_nspace > GETTY_NSPACE) {
1256                         sp->se_nspace = 0;
1257                         too_quick = 1;
1258                 }
1259         } else
1260                 sp->se_nspace = 0;
1261
1262         /*
1263          * fork(), not vfork() -- we can't afford to block.
1264          */
1265         if ((pid = fork()) == -1) {
1266                 emergency("can't fork for getty on port %s: %m", sp->se_device);
1267                 return -1;
1268         }
1269
1270         if (pid)
1271                 return pid;
1272
1273         if (too_quick) {
1274                 warning("getty repeating too quickly on port %s, sleeping %d secs",
1275                         sp->se_device, GETTY_SLEEP);
1276                 sleep((unsigned) GETTY_SLEEP);
1277         }
1278
1279         if (sp->se_window) {
1280                 start_window_system(sp);
1281                 sleep(WINDOW_WAIT);
1282         }
1283
1284         sigemptyset(&mask);
1285         sigprocmask(SIG_SETMASK, &mask, NULL);
1286
1287 #ifdef LOGIN_CAP
1288         setprocresources(RESOURCE_GETTY);
1289 #endif
1290         if (sp->se_type) {
1291                 /* Don't use malloc after fork */
1292                 strcpy(term, "TERM=");
1293                 strncat(term, sp->se_type, sizeof(term) - 6);
1294                 env[0] = term;
1295                 env[1] = NULL;
1296         }
1297         else
1298                 env[0] = NULL;
1299         execve(sp->se_getty_argv[0], sp->se_getty_argv, env);
1300         stall("can't exec getty '%s' for port %s: %m",
1301                 sp->se_getty_argv[0], sp->se_device);
1302         _exit(1);
1303 }
1304
1305 /*
1306  * Collect exit status for a child.
1307  * If an exiting login, start a new login running.
1308  */
1309 static void
1310 collect_child(pid_t pid)
1311 {
1312         session_t *sp, *sprev, *snext;
1313
1314         if (! sessions)
1315                 return;
1316
1317         if (! (sp = find_session(pid)))
1318                 return;
1319
1320         clear_session_logs(sp);
1321         del_session(sp);
1322         sp->se_process = 0;
1323
1324         if (sp->se_flags & SE_SHUTDOWN) {
1325                 if ((sprev = sp->se_prev) != NULL)
1326                         sprev->se_next = sp->se_next;
1327                 else
1328                         sessions = sp->se_next;
1329                 if ((snext = sp->se_next) != NULL)
1330                         snext->se_prev = sp->se_prev;
1331                 free_session(sp);
1332                 return;
1333         }
1334
1335         if ((pid = start_getty(sp)) == -1) {
1336                 /* serious trouble */
1337                 requested_transition = clean_ttys;
1338                 return;
1339         }
1340
1341         sp->se_process = pid;
1342         gettimeofday(&sp->se_started, NULL);
1343         add_session(sp);
1344 }
1345
1346 /*
1347  * Catch a signal and request a state transition.
1348  */
1349 static void
1350 transition_handler(int sig)
1351 {
1352
1353         switch (sig) {
1354         case SIGHUP:
1355                 requested_transition = clean_ttys;
1356                 break;
1357         case SIGUSR2:
1358                 howto = RB_POWEROFF;
1359                 /* FALLTHROUGH */
1360         case SIGUSR1:
1361                 howto |= RB_HALT;
1362                 /* FALLTHROUGH */
1363         case SIGINT:
1364                 Reboot = TRUE;
1365                 /* FALLTHROUGH */
1366         case SIGTERM:
1367                 requested_transition = death;
1368                 break;
1369         case SIGTSTP:
1370                 requested_transition = catatonia;
1371                 break;
1372         default:
1373                 requested_transition = 0;
1374                 break;
1375         }
1376 }
1377
1378 /*
1379  * Take the system multiuser.
1380  */
1381 static state_t
1382 f_multi_user(void)
1383 {
1384         pid_t pid;
1385         session_t *sp;
1386
1387         requested_transition = 0;
1388
1389         /*
1390          * If the administrator has not set the security level to -1
1391          * to indicate that the kernel should not run multiuser in secure
1392          * mode, and the run script has not set a higher level of security
1393          * than level 1, then put the kernel into secure mode.
1394          */
1395         if (getsecuritylevel() == 0)
1396                 setsecuritylevel(1);
1397
1398         for (sp = sessions; sp; sp = sp->se_next) {
1399                 if (sp->se_process)
1400                         continue;
1401                 if ((pid = start_getty(sp)) == -1) {
1402                         /* serious trouble */
1403                         requested_transition = clean_ttys;
1404                         break;
1405                 }
1406                 sp->se_process = pid;
1407                 gettimeofday(&sp->se_started, NULL);
1408                 add_session(sp);
1409         }
1410
1411         while (!requested_transition)
1412                 if ((pid = waitpid(-1, NULL, 0)) != -1)
1413                         collect_child(pid);
1414
1415         return requested_transition;
1416 }
1417
1418 /*
1419  * This is an (n*2)+(n^2) algorithm.  We hope it isn't run often...
1420  */
1421 static state_t
1422 f_clean_ttys(void)
1423 {
1424         session_t *sp, *sprev;
1425         struct ttyent *typ;
1426         int session_index = 0;
1427         int devlen;
1428         char *old_getty, *old_window, *old_type;
1429
1430         if (! sessions)
1431                 return multi_user;
1432
1433         /*
1434          * mark all sessions for death, (!SE_PRESENT)
1435          * as we find or create new ones they'll be marked as keepers,
1436          * we'll later nuke all the ones not found in /etc/ttys
1437          */
1438         for (sp = sessions; sp != NULL; sp = sp->se_next)
1439                 sp->se_flags &= ~SE_PRESENT;
1440
1441         devlen = sizeof(_PATH_DEV) - 1;
1442         while ((typ = getttyent()) != NULL) {
1443                 ++session_index;
1444
1445                 adjttyent(typ);
1446                 for (sprev = NULL, sp = sessions; sp; sprev = sp, sp = sp->se_next)
1447                         if (strcmp(typ->ty_name, sp->se_device + devlen) == 0)
1448                                 break;
1449
1450                 if (sp) {
1451                         /* we want this one to live */
1452                         sp->se_flags |= SE_PRESENT;
1453                         if (sp->se_index != session_index) {
1454                                 warning("port %s changed utmp index from %d to %d",
1455                                        sp->se_device, sp->se_index,
1456                                        session_index);
1457                                 sp->se_index = session_index;
1458                         }
1459                         if ((typ->ty_status & TTY_ON) == 0 ||
1460                             typ->ty_getty == 0) {
1461                                 sp->se_flags |= SE_SHUTDOWN;
1462                                 kill(sp->se_process, SIGHUP);
1463                                 continue;
1464                         }
1465                         sp->se_flags &= ~SE_SHUTDOWN;
1466                         old_getty = sp->se_getty ? strdup(sp->se_getty) : 0;
1467                         old_window = sp->se_window ? strdup(sp->se_window) : 0;
1468                         old_type = sp->se_type ? strdup(sp->se_type) : 0;
1469                         if (setupargv(sp, typ) == 0) {
1470                                 warning("can't parse getty for port %s",
1471                                         sp->se_device);
1472                                 sp->se_flags |= SE_SHUTDOWN;
1473                                 kill(sp->se_process, SIGHUP);
1474                         }
1475                         else if (   !old_getty
1476                                  || (!old_type && sp->se_type)
1477                                  || (old_type && !sp->se_type)
1478                                  || (!old_window && sp->se_window)
1479                                  || (old_window && !sp->se_window)
1480                                  || (strcmp(old_getty, sp->se_getty) != 0)
1481                                  || (old_window && strcmp(old_window, sp->se_window) != 0)
1482                                  || (old_type && strcmp(old_type, sp->se_type) != 0)
1483                                 ) {
1484                                 /* Don't set SE_SHUTDOWN here */
1485                                 sp->se_nspace = 0;
1486                                 sp->se_started.tv_sec = sp->se_started.tv_usec = 0;
1487                                 kill(sp->se_process, SIGHUP);
1488                         }
1489                         if (old_getty)
1490                                 free(old_getty);
1491                         if (old_window)
1492                                 free(old_window);
1493                         if (old_type)
1494                                 free(old_type);
1495                         continue;
1496                 }
1497
1498                 new_session(sprev, session_index, typ);
1499         }
1500
1501         endttyent();
1502
1503         /*
1504          * sweep through and kill all deleted sessions
1505          * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
1506          */
1507         for (sp = sessions; sp != NULL; sp = sp->se_next) {
1508                 if ((sp->se_flags & SE_PRESENT) == 0) {
1509                         sp->se_flags |= SE_SHUTDOWN;
1510                         kill(sp->se_process, SIGHUP);
1511                 }
1512         }
1513
1514         return multi_user;
1515 }
1516
1517 /*
1518  * Block further logins.
1519  */
1520 static state_t
1521 f_catatonia(void)
1522 {
1523         session_t *sp;
1524
1525         for (sp = sessions; sp; sp = sp->se_next)
1526                 sp->se_flags |= SE_SHUTDOWN;
1527
1528         return multi_user;
1529 }
1530
1531 /*
1532  * Note SIGALRM.
1533  */
1534 static void
1535 alrm_handler(int sig __unused)
1536 {
1537         clang = 1;
1538 }
1539
1540 /*
1541  * Bring the system down to single user.
1542  */
1543 static state_t
1544 f_death(void)
1545 {
1546         session_t *sp;
1547         int i;
1548         pid_t pid;
1549         static const int death_sigs[2] = { SIGTERM, SIGKILL };
1550
1551         /* NB: should send a message to the session logger to avoid blocking. */
1552 #ifdef SUPPORT_UTMPX
1553         logwtmpx("~", "shutdown", "", 0, INIT_PROCESS);
1554 #endif
1555         logwtmp("~", "shutdown", "");
1556
1557         for (sp = sessions; sp; sp = sp->se_next) {
1558                 sp->se_flags |= SE_SHUTDOWN;
1559                 kill(sp->se_process, SIGHUP);
1560         }
1561
1562         /* Try to run the rc.shutdown script within a period of time */
1563         runshutdown();
1564
1565         for (i = 0; i < 2; ++i) {
1566                 if (kill(-1, death_sigs[i]) == -1 && errno == ESRCH)
1567                         return single_user;
1568
1569                 clang = 0;
1570                 alarm(DEATH_WATCH);
1571                 do
1572                         if ((pid = waitpid(-1, NULL, 0)) != -1)
1573                                 collect_child(pid);
1574                 while (clang == 0 && errno != ECHILD);
1575
1576                 if (errno == ECHILD)
1577                         return single_user;
1578         }
1579
1580         warning("some processes would not die; ps axl advised");
1581
1582         return single_user;
1583 }
1584
1585 /*
1586  * Run the system shutdown script.
1587  *
1588  * Exit codes:      XXX I should document more
1589  * -2       shutdown script terminated abnormally
1590  * -1       fatal error - can't run script
1591  * 0        good.
1592  * >0       some error (exit code)
1593  */
1594 static int
1595 runshutdown(void)
1596 {
1597         pid_t pid, wpid;
1598         int status;
1599         int shutdowntimeout;
1600         size_t len;
1601         const char *argv[4];
1602         struct sigaction sa;
1603         struct stat sb;
1604
1605         /*
1606          * rc.shutdown is optional, so to prevent any unnecessary
1607          * complaints from the shell we simply don't run it if the
1608          * file does not exist. If the stat() here fails for other
1609          * reasons, we'll let the shell complain.
1610          */
1611         if (stat(_PATH_RUNDOWN, &sb) == -1 && errno == ENOENT)
1612                 return 0;
1613
1614         if ((pid = fork()) == 0) {
1615                 int     fd;
1616
1617                 /* Assume that init already grab console as ctty before */
1618
1619                 sigemptyset(&sa.sa_mask);
1620                 sa.sa_flags = 0;
1621                 sa.sa_handler = SIG_IGN;
1622                 sigaction(SIGTSTP, &sa, NULL);
1623                 sigaction(SIGHUP, &sa, NULL);
1624
1625                 if ((fd = open(_PATH_CONSOLE, O_RDWR)) == -1)
1626                     warning("can't open %s: %m", _PATH_CONSOLE);
1627                 else {
1628                     dup2(fd, 0);
1629                     dup2(fd, 1);
1630                     dup2(fd, 2);
1631                     if (fd > 2)
1632                         close(fd);
1633                 }
1634
1635                 /*
1636                  * Run the shutdown script.
1637                  */
1638                 argv[0] = "sh";
1639                 argv[1] = _PATH_RUNDOWN;
1640                 if (Reboot)
1641                         argv[2] = "reboot";
1642                 else
1643                         argv[2] = "single";
1644                 argv[3] = NULL;
1645
1646                 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
1647
1648 #ifdef LOGIN_CAP
1649                 setprocresources(RESOURCE_RC);
1650 #endif
1651                 execv(_PATH_BSHELL, __DECONST(char **, argv));
1652                 warning("can't exec %s for %s: %m", _PATH_BSHELL, _PATH_RUNDOWN);
1653                 _exit(1);       /* force single user mode */
1654         }
1655
1656         if (pid == -1) {
1657                 emergency("can't fork for %s on %s: %m",
1658                         _PATH_BSHELL, _PATH_RUNDOWN);
1659                 while (waitpid(-1, NULL, WNOHANG) > 0)
1660                         continue;
1661                 sleep(STALL_TIMEOUT);
1662                 return -1;
1663         }
1664
1665         len = sizeof(shutdowntimeout);
1666         if (sysctlbyname("kern.init_shutdown_timeout",
1667                          &shutdowntimeout,
1668                          &len, NULL, 0) == -1 || shutdowntimeout < 2)
1669             shutdowntimeout = DEATH_SCRIPT;
1670         alarm(shutdowntimeout);
1671         clang = 0;
1672         /*
1673          * Copied from single_user().  This is a bit paranoid.
1674          * Use the same ALRM handler.
1675          */
1676         do {
1677                 if ((wpid = waitpid(-1, &status, WUNTRACED)) != -1)
1678                         collect_child(wpid);
1679                 if (clang == 1) {
1680                         /* we were waiting for the sub-shell */
1681                         kill(wpid, SIGTERM);
1682                         warning("timeout expired for %s on %s: %m; going to single user mode",
1683                                 _PATH_BSHELL, _PATH_RUNDOWN);
1684                         return -1;
1685                 }
1686                 if (wpid == -1) {
1687                         if (errno == EINTR)
1688                                 continue;
1689                         warning("wait for %s on %s failed: %m; going to single user mode",
1690                                 _PATH_BSHELL, _PATH_RUNDOWN);
1691                         return -1;
1692                 }
1693                 if (wpid == pid && WIFSTOPPED(status)) {
1694                         warning("init: %s on %s stopped, restarting\n",
1695                                 _PATH_BSHELL, _PATH_RUNDOWN);
1696                         kill(pid, SIGCONT);
1697                         wpid = -1;
1698                 }
1699         } while (wpid != pid && !clang);
1700
1701         /* Turn off the alarm */
1702         alarm(0);
1703
1704         if (WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM &&
1705             requested_transition == catatonia) {
1706                 /*
1707                  * /etc/rc.shutdown executed /sbin/reboot;
1708                  * wait for the end quietly
1709                  */
1710                 sigset_t s;
1711
1712                 sigfillset(&s);
1713                 for (;;)
1714                         sigsuspend(&s);
1715         }
1716
1717         if (!WIFEXITED(status)) {
1718                 warning("%s on %s terminated abnormally, going to single user mode",
1719                         _PATH_BSHELL, _PATH_RUNDOWN);
1720                 return -2;
1721         }
1722
1723         if ((status = WEXITSTATUS(status)) != 0)
1724                 warning("%s returned status %d", _PATH_RUNDOWN, status);
1725
1726         return status;
1727 }
1728
1729 static char *
1730 strk(char *p)
1731 {
1732     static char *t;
1733     char *q;
1734     int c;
1735
1736     if (p)
1737         t = p;
1738     if (!t)
1739         return 0;
1740
1741     c = *t;
1742     while (c == ' ' || c == '\t' )
1743         c = *++t;
1744     if (!c) {
1745         t = NULL;
1746         return 0;
1747     }
1748     q = t;
1749     if (c == '\'') {
1750         c = *++t;
1751         q = t;
1752         while (c && c != '\'')
1753             c = *++t;
1754         if (!c)  /* unterminated string */
1755             q = t = NULL;
1756         else
1757             *t++ = 0;
1758     } else {
1759         while (c && c != ' ' && c != '\t' )
1760             c = *++t;
1761         *t++ = 0;
1762         if (!c)
1763             t = NULL;
1764     }
1765     return q;
1766 }
1767
1768 #ifdef LOGIN_CAP
1769 static void
1770 setprocresources(const char *cname)
1771 {
1772         login_cap_t *lc;
1773         if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
1774                 setusercontext(lc, NULL, 0, LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
1775                 login_close(lc);
1776         }
1777 }
1778 #endif
1779
1780 #ifdef SUPPORT_UTMPX
1781 static void
1782 session_utmpx(const session_t *sp, int add)
1783 {
1784         const char *name = sp->se_getty ? sp->se_getty :
1785             (sp->se_window ? sp->se_window : "");
1786         const char *line = sp->se_device + sizeof(_PATH_DEV) - 1;
1787
1788         make_utmpx(name, line, add ? LOGIN_PROCESS : DEAD_PROCESS,
1789             sp->se_process, &sp->se_started, sp->se_index);
1790 }
1791
1792 static void
1793 make_utmpx(const char *name, const char *line, int type, pid_t pid,
1794     const struct timeval *tv, int session)
1795 {
1796         struct utmpx ut;
1797         const char *eline;
1798
1799         (void)memset(&ut, 0, sizeof(ut));
1800         (void)strlcpy(ut.ut_name, name, sizeof(ut.ut_name));
1801         ut.ut_type = type;
1802         (void)strlcpy(ut.ut_line, line, sizeof(ut.ut_line));
1803         ut.ut_pid = pid;
1804         if (tv)
1805                 ut.ut_tv = *tv;
1806         else
1807                 (void)gettimeofday(&ut.ut_tv, NULL);
1808         ut.ut_session = session;
1809
1810         eline = line + strlen(line);
1811         if ((size_t)(eline - line) >= sizeof(ut.ut_id))
1812                 line = eline - sizeof(ut.ut_id);
1813         (void)strncpy(ut.ut_id, line, sizeof(ut.ut_id));
1814
1815         if (pututxline(&ut) == NULL)
1816                 warning("can't add utmpx record for `%s': %m", ut.ut_line);
1817         endutxent();
1818 }
1819
1820 static char
1821 get_runlevel(const state_t s)
1822 {
1823         if (s == single_user)
1824                 return SINGLE_USER;
1825         if (s == runcom)
1826                 return RUNCOM;
1827         if (s == read_ttys)
1828                 return READ_TTYS;
1829         if (s == multi_user)
1830                 return MULTI_USER;
1831         if (s == clean_ttys)
1832                 return CLEAN_TTYS;
1833         if (s == catatonia)
1834                 return CATATONIA;
1835         return DEATH;
1836 }
1837
1838 static void
1839 utmpx_set_runlevel(char old, char new)
1840 {
1841         struct utmpx ut;
1842
1843         /*
1844          * Don't record any transitions until we did the first transition
1845          * to read ttys, which is when we are guaranteed to have a read-write
1846          * /var. Perhaps use a different variable for this?
1847          */
1848         if (sessions == NULL)
1849                 return;
1850
1851         (void)memset(&ut, 0, sizeof(ut));
1852         (void)snprintf(ut.ut_line, sizeof(ut.ut_line), RUNLVL_MSG, new);
1853         ut.ut_type = RUN_LVL;
1854         (void)gettimeofday(&ut.ut_tv, NULL);
1855         ut.ut_exit.e_exit = old;
1856         ut.ut_exit.e_termination = new;
1857         if (pututxline(&ut) == NULL)
1858                 warning("can't add utmpx record for `runlevel': %m");
1859         endutxent();
1860 }
1861 #endif