sbin/shutdown/shutdown.c

   1 /*
   2  * Copyright (c) 1988, 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1988, 1990, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)shutdown.c       8.4 (Berkeley) 4/28/95
  31  * $FreeBSD: src/sbin/shutdown/shutdown.c,v 1.21.2.1 2001/07/30 10:38:08 dd Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/time.h>
  36 #include <sys/resource.h>
  37 #include <sys/syslog.h>
  38
  39 #include <ctype.h>
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <pwd.h>
  44 #include <setjmp.h>
  45 #include <signal.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50
  51 #include "pathnames.h"
  52
  53 #ifdef DEBUG
  54 #undef _PATH_NOLOGIN
  55 #define _PATH_NOLOGIN   "./nologin"
  56 #endif
  57
  58 #define H               *60*60
  59 #define M               *60
  60 #define S               *1
  61 #define NOLOG_TIME      5*60
  62 static struct interval {
  63         int timeleft, timetowait;
  64 } tlist[] = {
  65         { 10 H,  5 H },
  66         {  5 H,  3 H },
  67         {  2 H,  1 H },
  68         {  1 H, 30 M },
  69         { 30 M, 10 M },
  70         { 20 M, 10 M },
  71         { 10 M,  5 M },
  72         {  5 M,  3 M },
  73         {  2 M,  1 M },
  74         {  1 M, 30 S },
  75         { 30 S, 30 S },
  76         {  0  ,  0   }
  77 };
  78 #undef H
  79 #undef M
  80 #undef S
  81
  82 static time_t offset, shuttime;
  83 static int dohalt, dopower, doreboot, killflg, mbuflen, oflag;
  84 static char mbuf[BUFSIZ];
  85 static const char *nosync, *whom;
  86
  87 static void badtime(void);
  88 static void die_you_gravy_sucking_pig_dog(void);
  89 static void finish(int);
  90 static void getoffset(char *);
  91 static void loop(void);
  92 static void nolog(void);
  93 static void timeout(int);
  94 static void timewarn(int);
  95 static void usage(const char *);
  96
  97 extern const char **environ;
  98
  99 int
 100 main(int argc, char **argv)
 101 {
 102         char *p, *endp;
 103         struct passwd *pw;
 104         int arglen, ch, len, readstdin;
 105
 106 #ifndef DEBUG
 107         if (geteuid())
 108                 errx(1, "NOT super-user");
 109 #endif
 110
 111         nosync = NULL;
 112         readstdin = 0;
 113
 114         /*
 115          * Test for the special case where the utility is called as
 116          * "poweroff", for which it runs 'shutdown -p now'.
 117          */
 118         if ((p = strrchr(argv[0], '/')) == NULL)
 119                 p = argv[0];
 120         else
 121                 ++p;
 122         if (strcmp(p, "poweroff") == 0) {
 123                 if (getopt(argc, argv, "") != -1)
 124                         usage(NULL);
 125                 argc -= optind;
 126                 argv += optind;
 127                 if (argc != 0)
 128                         usage(NULL);
 129                 dopower = 1;
 130                 offset = 0;
 131                 (void)time(&shuttime);
 132                 goto poweroff;
 133         }
 134
 135         while ((ch = getopt(argc, argv, "-hknopr")) != -1)
 136                 switch (ch) {
 137                 case '-':
 138                         readstdin = 1;
 139                         break;
 140                 case 'h':
 141                         dohalt = 1;
 142                         break;
 143                 case 'k':
 144                         killflg = 1;
 145                         break;
 146                 case 'n':
 147                         nosync = "-n";
 148                         break;
 149                 case 'o':
 150                         oflag = 1;
 151                         break;
 152                 case 'p':
 153                         dopower = 1;
 154                         break;
 155                 case 'r':
 156                         doreboot = 1;
 157                         break;
 158                 case '?':
 159                 default:
 160                         usage(NULL);
 161                 }
 162         argc -= optind;
 163         argv += optind;
 164
 165 #ifdef RESCUE
 166         oflag = 1;
 167 #endif
 168
 169         if (argc < 1)
 170                 usage(NULL);
 171
 172         if (killflg + doreboot + dohalt + dopower > 1)
 173                 usage("incompatible switches -h, -k, -p and -r");
 174
 175         if (oflag && !(dohalt || dopower || doreboot))
 176                 usage("-o requires -h, -p or -r");
 177
 178         if (nosync != NULL && !oflag)
 179                 usage("-n requires -o");
 180
 181         getoffset(*argv++);
 182
 183 poweroff:
 184         if (*argv) {
 185                 for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
 186                         arglen = strlen(*argv);
 187                         if ((len -= arglen) <= 2)
 188                                 break;
 189                         if (p != mbuf)
 190                                 *p++ = ' ';
 191                         memmove(p, *argv, arglen);
 192                         p += arglen;
 193                 }
 194                 *p = '\n';
 195                 *++p = '\0';
 196         }
 197
 198         if (readstdin) {
 199                 p = mbuf;
 200                 endp = mbuf + sizeof(mbuf) - 2;
 201                 for (;;) {
 202                         if (!fgets(p, endp - p + 1, stdin))
 203                                 break;
 204                         for (; *p &&  p < endp; ++p);
 205                         if (p == endp) {
 206                                 *p = '\n';
 207                                 *++p = '\0';
 208                                 break;
 209                         }
 210                 }
 211         }
 212         mbuflen = strlen(mbuf);
 213
 214         if (offset)
 215                 printf("Shutdown at %.24s.\n", ctime(&shuttime));
 216         else
 217                 printf("Shutdown NOW!\n");
 218
 219         if (!(whom = getlogin()))
 220                 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 221
 222 #ifdef DEBUG
 223         putc('\n', stdout);
 224 #else
 225         setpriority(PRIO_PROCESS, 0, PRIO_MIN);
 226         {
 227                 int forkpid;
 228
 229                 forkpid = fork();
 230                 if (forkpid == -1)
 231                         err(1, "fork");
 232                 if (forkpid)
 233                         errx(0, "[pid %d]", forkpid);
 234         }
 235         setsid();
 236 #endif
 237         openlog("shutdown", LOG_CONS, LOG_AUTH);
 238         loop();
 239         return(0);
 240 }
 241
 242 static void
 243 loop(void)
 244 {
 245         struct interval *tp;
 246         u_int sltime;
 247         int logged;
 248
 249         if (offset <= NOLOG_TIME) {
 250                 logged = 1;
 251                 nolog();
 252         }
 253         else
 254                 logged = 0;
 255         tp = tlist;
 256         if (tp->timeleft < offset)
 257                 sleep((u_int)(offset - tp->timeleft));
 258         else {
 259                 while (tp->timeleft && offset < tp->timeleft)
 260                         ++tp;
 261                 /*
 262                  * Warn now, if going to sleep more than a fifth of
 263                  * the next wait time.
 264                  */
 265                 if ((sltime = offset - tp->timeleft)) {
 266                         if (sltime > (u_int)(tp->timetowait / 5))
 267                                 timewarn(offset);
 268                         sleep(sltime);
 269                 }
 270         }
 271         for (;; ++tp) {
 272                 timewarn(tp->timeleft);
 273                 if (!logged && tp->timeleft <= NOLOG_TIME) {
 274                         logged = 1;
 275                         nolog();
 276                 }
 277                 sleep((u_int)tp->timetowait);
 278                 if (!tp->timeleft)
 279                         break;
 280         }
 281         die_you_gravy_sucking_pig_dog();
 282 }
 283
 284 static jmp_buf alarmbuf;
 285
 286 static const char *restricted_environ[] = {
 287         "PATH=" _PATH_STDPATH,
 288         NULL
 289 };
 290
 291 static void
 292 timewarn(int timeleft)
 293 {
 294         static int first;
 295         static char hostname[MAXHOSTNAMELEN + 1];
 296         FILE *pf;
 297         char wcmd[MAXPATHLEN + 4];
 298
 299         if (!first++)
 300                 gethostname(hostname, sizeof(hostname));
 301
 302         /* undoc -n option to wall suppresses normal wall banner */
 303         snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
 304         environ = restricted_environ;
 305         if (!(pf = popen(wcmd, "w"))) {
 306                 syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
 307                 return;
 308         }
 309
 310         fprintf(pf,
 311             "\007*** %sSystem shutdown message from %s@%s ***\007\n",
 312             timeleft ? "": "FINAL ", whom, hostname);
 313
 314         if (timeleft > 10*60)
 315                 fprintf(pf, "System going down at %5.5s\n\n",
 316                     ctime(&shuttime) + 11);
 317         else if (timeleft > 59)
 318                 fprintf(pf, "System going down in %d minute%s\n\n",
 319                     timeleft / 60, (timeleft > 60) ? "s" : "");
 320         else if (timeleft)
 321                 fprintf(pf, "System going down in %s30 seconds\n\n",
 322                               (offset > 0 && offset < 30 ? "less than " : ""));
 323         else
 324                 fprintf(pf, "System going down IMMEDIATELY\n\n");
 325
 326         if (mbuflen)
 327                 fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
 328
 329         /*
 330          * play some games, just in case wall doesn't come back
 331          * probably unnecessary, given that wall is careful.
 332          */
 333         if (!setjmp(alarmbuf)) {
 334                 signal(SIGALRM, timeout);
 335                 alarm((u_int)30);
 336                 pclose(pf);
 337                 alarm((u_int)0);
 338                 signal(SIGALRM, SIG_DFL);
 339         }
 340 }
 341
 342 static void
 343 timeout(int signo __unused)
 344 {
 345         longjmp(alarmbuf, 1);
 346 }
 347
 348 static void
 349 die_you_gravy_sucking_pig_dog(void)
 350 {
 351 #ifndef DEBUG
 352         char *empty_environ[] = { NULL };
 353 #endif
 354
 355         syslog(LOG_NOTICE, "%s by %s: %s",
 356             doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
 357             "shutdown", whom, mbuf);
 358         sleep(2);
 359
 360         printf("\r\nSystem shutdown time has arrived\007\007\r\n");
 361         if (killflg) {
 362                 printf("\rbut you'll have to do it yourself\r\n");
 363                 exit(0);
 364         }
 365 #ifdef DEBUG
 366         if (doreboot)
 367                 printf("reboot");
 368         else if (dohalt)
 369                 printf("halt");
 370         else if (dopower)
 371                 printf("power-down");
 372         if (nosync != NULL)
 373                 printf(" no sync");
 374         printf("\nkill -HUP 1\n");
 375 #else
 376         if (!oflag) {
 377                 kill(1, doreboot ? SIGINT :     /* reboot */
 378                         dohalt ? SIGUSR1 :      /* halt */
 379                         dopower ? SIGUSR2 :     /* power-down */
 380                         SIGTERM);               /* single-user */
 381         } else {
 382                 if (doreboot) {
 383                         execle(_PATH_REBOOT, "reboot", "-l", nosync,
 384                                 NULL, empty_environ);
 385                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 386                                 _PATH_REBOOT);
 387                         warn(_PATH_REBOOT);
 388                 }
 389                 else if (dohalt) {
 390                         execle(_PATH_HALT, "halt", "-l", nosync,
 391                                 NULL, empty_environ);
 392                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 393                                 _PATH_HALT);
 394                         warn(_PATH_HALT);
 395                 }
 396                 else if (dopower) {
 397                         execle(_PATH_HALT, "halt", "-l", "-p", nosync,
 398                                 NULL, empty_environ);
 399                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 400                                 _PATH_HALT);
 401                         warn(_PATH_HALT);
 402                 }
 403                 kill(1, SIGTERM);               /* to single-user */
 404         }
 405 #endif
 406         finish(0);
 407 }
 408
 409 #define ATOI2(p)        (p[0] - '0') * 10 + (p[1] - '0'); p += 2;
 410
 411 static void
 412 getoffset(char *timearg)
 413 {
 414         struct tm *lt;
 415         char *p;
 416         time_t now;
 417         int maybe_today, this_year;
 418         char *timeunit;
 419
 420         time(&now);
 421
 422         if (!strcasecmp(timearg, "now")) {              /* now */
 423                 offset = 0;
 424                 shuttime = now;
 425                 return;
 426         }
 427
 428         if (*timearg == '+') {                          /* +minutes */
 429                 if (!isdigit(*++timearg))
 430                         badtime();
 431                 errno = 0;
 432                 offset = strtol(timearg, &timeunit, 10);
 433                 if (offset < 0 || offset == LONG_MAX || errno != 0)
 434                         badtime();
 435                 if (timeunit[0] == '\0' || strcasecmp(timeunit, "m") == 0 ||
 436                     strcasecmp(timeunit, "min") == 0 ||
 437                     strcasecmp(timeunit, "mins") == 0) {
 438                         offset *= 60;
 439                 } else if (strcasecmp(timeunit, "h") == 0 ||
 440                            strcasecmp(timeunit, "hour") == 0 ||
 441                            strcasecmp(timeunit, "hours") == 0) {
 442                         offset *= 60 * 60;
 443                 } else if (strcasecmp(timeunit, "s") == 0 ||
 444                            strcasecmp(timeunit, "sec") == 0 ||
 445                            strcasecmp(timeunit, "secs") == 0) {
 446                         offset *= 1;
 447                 } else {
 448                         badtime();
 449                 }
 450                 /* if ((offset = atoi(timearg) * 60) < 0) */
 451                 /*      badtime(); */
 452                 shuttime = now + offset;
 453                 return;
 454         }
 455
 456         /* handle hh:mm by getting rid of the colon */
 457         for (p = timearg; *p; ++p)
 458                 if (!isascii(*p) || !isdigit(*p)) {
 459                         if (*p == ':' && strlen(p) == 3) {
 460                                 p[0] = p[1];
 461                                 p[1] = p[2];
 462                                 p[2] = '\0';
 463                         }
 464                         else
 465                                 badtime();
 466                 }
 467
 468         unsetenv("TZ");                                 /* OUR timezone */
 469         lt = localtime(&now);                           /* current time val */
 470         maybe_today = 1;
 471
 472         switch(strlen(timearg)) {
 473         case 10:
 474                 this_year = lt->tm_year;
 475                 lt->tm_year = ATOI2(timearg);
 476                 /*
 477                  * check if the specified year is in the next century.
 478                  * allow for one year of user error as many people will
 479                  * enter n - 1 at the start of year n.
 480                  */
 481                 if (lt->tm_year < (this_year % 100) - 1)
 482                         lt->tm_year += 100;
 483                 /* adjust for the year 2000 and beyond */
 484                 lt->tm_year += (this_year - (this_year % 100));
 485                 /* FALLTHROUGH */
 486         case 8:
 487                 lt->tm_mon = ATOI2(timearg);
 488                 if (--lt->tm_mon < 0 || lt->tm_mon > 11)
 489                         badtime();
 490                 /* FALLTHROUGH */
 491         case 6:
 492                 maybe_today = 0;
 493                 lt->tm_mday = ATOI2(timearg);
 494                 if (lt->tm_mday < 1 || lt->tm_mday > 31)
 495                         badtime();
 496                 /* FALLTHROUGH */
 497         case 4:
 498                 lt->tm_hour = ATOI2(timearg);
 499                 if (lt->tm_hour < 0 || lt->tm_hour > 23)
 500                         badtime();
 501                 lt->tm_min = ATOI2(timearg);
 502                 if (lt->tm_min < 0 || lt->tm_min > 59)
 503                         badtime();
 504                 lt->tm_sec = 0;
 505                 if ((shuttime = mktime(lt)) == -1)
 506                         badtime();
 507
 508                 if ((offset = shuttime - now) < 0) {
 509                         if (!maybe_today)
 510                                 errx(1, "that time is already past.");
 511
 512                         /*
 513                          * If the user only gave a time, assume that
 514                          * any time earlier than the current time
 515                          * was intended to be that time tomorrow.
 516                          */
 517                         lt->tm_mday++;
 518                         if ((shuttime = mktime(lt)) == -1)
 519                                 badtime();
 520                         if ((offset = shuttime - now) < 0) {
 521                                 errx(1, "tomorrow is before today?");
 522                         }
 523                 }
 524                 break;
 525         default:
 526                 badtime();
 527         }
 528 }
 529
 530 #define NOMSG   "\n\nNO LOGINS: System going down at "
 531 static void
 532 nolog(void)
 533 {
 534         int logfd;
 535         char *ct;
 536
 537         unlink(_PATH_NOLOGIN);  /* in case linked to another file */
 538         signal(SIGINT, finish);
 539         signal(SIGHUP, finish);
 540         signal(SIGQUIT, finish);
 541         signal(SIGTERM, finish);
 542         if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
 543             0664)) >= 0) {
 544                 write(logfd, NOMSG, sizeof(NOMSG) - 1);
 545                 ct = ctime(&shuttime);
 546                 write(logfd, ct + 11, 5);
 547                 write(logfd, "\n\n", 2);
 548                 write(logfd, mbuf, strlen(mbuf));
 549                 close(logfd);
 550         }
 551 }
 552
 553 static void
 554 finish(int signo __unused)
 555 {
 556         if (!killflg)
 557                 unlink(_PATH_NOLOGIN);
 558         exit(0);
 559 }
 560
 561 static void
 562 badtime(void)
 563 {
 564         errx(1, "bad time format");
 565 }
 566
 567 static void
 568 usage(const char *cp)
 569 {
 570         if (cp != NULL)
 571                 warnx("%s", cp);
 572         fprintf(stderr,
 573             "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]]"
 574             " time [warning-message ...]\n"
 575             "       poweroff\n");
 576         exit(1);
 577 }