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  * 4. 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  * $DragonFly: src/sbin/shutdown/shutdown.c,v 1.6 2005/01/02 01:22:49 cpressey Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/time.h>
  37 #include <sys/resource.h>
  38 #include <sys/syslog.h>
  39
  40 #include <ctype.h>
  41 #include <err.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 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 void badtime(void);
  88 void die_you_gravy_sucking_pig_dog(void);
  89 void finish(int);
  90 void getoffset(char *);
  91 void loop(void);
  92 void nolog(void);
  93 void timeout(int);
  94 void timewarn(int);
  95 void usage(const char *);
  96
  97 int
  98 main(int argc, char **argv)
  99 {
 100         char *p, *endp;
 101         struct passwd *pw;
 102         int arglen, ch, len, readstdin;
 103
 104 #ifndef DEBUG
 105         if (geteuid())
 106                 errx(1, "NOT super-user");
 107 #endif
 108         nosync = NULL;
 109         readstdin = 0;
 110         while ((ch = getopt(argc, argv, "-hknopr")) != -1)
 111                 switch (ch) {
 112                 case '-':
 113                         readstdin = 1;
 114                         break;
 115                 case 'h':
 116                         dohalt = 1;
 117                         break;
 118                 case 'k':
 119                         killflg = 1;
 120                         break;
 121                 case 'n':
 122                         nosync = "-n";
 123                         break;
 124                 case 'o':
 125                         oflag = 1;
 126                         break;
 127                 case 'p':
 128                         dopower = 1;
 129                         break;
 130                 case 'r':
 131                         doreboot = 1;
 132                         break;
 133                 case '?':
 134                 default:
 135                         usage(NULL);
 136                 }
 137         argc -= optind;
 138         argv += optind;
 139
 140         if (argc < 1)
 141                 usage(NULL);
 142
 143         if (killflg + doreboot + dohalt + dopower > 1)
 144                 usage("incompatible switches -h, -k, -p and -r");
 145
 146         if (oflag && !(dohalt || dopower || doreboot))
 147                 usage("-o requires -h, -p or -r");
 148
 149         if (nosync != NULL && !oflag)
 150                 usage("-n requires -o");
 151
 152         getoffset(*argv++);
 153
 154         if (*argv) {
 155                 for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
 156                         arglen = strlen(*argv);
 157                         if ((len -= arglen) <= 2)
 158                                 break;
 159                         if (p != mbuf)
 160                                 *p++ = ' ';
 161                         memmove(p, *argv, arglen);
 162                         p += arglen;
 163                 }
 164                 *p = '\n';
 165                 *++p = '\0';
 166         }
 167
 168         if (readstdin) {
 169                 p = mbuf;
 170                 endp = mbuf + sizeof(mbuf) - 2;
 171                 for (;;) {
 172                         if (!fgets(p, endp - p + 1, stdin))
 173                                 break;
 174                         for (; *p &&  p < endp; ++p);
 175                         if (p == endp) {
 176                                 *p = '\n';
 177                                 *++p = '\0';
 178                                 break;
 179                         }
 180                 }
 181         }
 182         mbuflen = strlen(mbuf);
 183
 184         if (offset)
 185                 printf("Shutdown at %.24s.\n", ctime(&shuttime));
 186         else
 187                 printf("Shutdown NOW!\n");
 188
 189         if (!(whom = getlogin()))
 190                 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 191
 192 #ifdef DEBUG
 193         putc('\n', stdout);
 194 #else
 195         setpriority(PRIO_PROCESS, 0, PRIO_MIN);
 196         {
 197                 int forkpid;
 198
 199                 forkpid = fork();
 200                 if (forkpid == -1)
 201                         err(1, "fork");
 202                 if (forkpid)
 203                         errx(0, "[pid %d]", forkpid);
 204         }
 205         setsid();
 206 #endif
 207         openlog("shutdown", LOG_CONS, LOG_AUTH);
 208         loop();
 209         return(0);
 210 }
 211
 212 void
 213 loop(void)
 214 {
 215         struct interval *tp;
 216         u_int sltime;
 217         int logged;
 218
 219         if (offset <= NOLOG_TIME) {
 220                 logged = 1;
 221                 nolog();
 222         }
 223         else
 224                 logged = 0;
 225         tp = tlist;
 226         if (tp->timeleft < offset)
 227                 sleep((u_int)(offset - tp->timeleft));
 228         else {
 229                 while (tp->timeleft && offset < tp->timeleft)
 230                         ++tp;
 231                 /*
 232                  * Warn now, if going to sleep more than a fifth of
 233                  * the next wait time.
 234                  */
 235                 if ((sltime = offset - tp->timeleft)) {
 236                         if (sltime > (u_int)(tp->timetowait / 5))
 237                                 timewarn(offset);
 238                         sleep(sltime);
 239                 }
 240         }
 241         for (;; ++tp) {
 242                 timewarn(tp->timeleft);
 243                 if (!logged && tp->timeleft <= NOLOG_TIME) {
 244                         logged = 1;
 245                         nolog();
 246                 }
 247                 sleep((u_int)tp->timetowait);
 248                 if (!tp->timeleft)
 249                         break;
 250         }
 251         die_you_gravy_sucking_pig_dog();
 252 }
 253
 254 static jmp_buf alarmbuf;
 255
 256 static const char *restricted_environ[] = {
 257         "PATH=" _PATH_STDPATH,
 258         NULL
 259 };
 260
 261 extern const char **environ;
 262
 263 void
 264 timewarn(int timeleft)
 265 {
 266         static int first;
 267         static char hostname[MAXHOSTNAMELEN + 1];
 268         FILE *pf;
 269         char wcmd[MAXPATHLEN + 4];
 270
 271         if (!first++)
 272                 gethostname(hostname, sizeof(hostname));
 273
 274         /* undoc -n option to wall suppresses normal wall banner */
 275         snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
 276         environ = restricted_environ;
 277         if (!(pf = popen(wcmd, "w"))) {
 278                 syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
 279                 return;
 280         }
 281
 282         fprintf(pf,
 283             "\007*** %sSystem shutdown message from %s@%s ***\007\n",
 284             timeleft ? "": "FINAL ", whom, hostname);
 285
 286         if (timeleft > 10*60)
 287                 fprintf(pf, "System going down at %5.5s\n\n",
 288                     ctime(&shuttime) + 11);
 289         else if (timeleft > 59)
 290                 fprintf(pf, "System going down in %d minute%s\n\n",
 291                     timeleft / 60, (timeleft > 60) ? "s" : "");
 292         else if (timeleft)
 293                 fprintf(pf, "System going down in 30 seconds\n\n");
 294         else
 295                 fprintf(pf, "System going down IMMEDIATELY\n\n");
 296
 297         if (mbuflen)
 298                 fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
 299
 300         /*
 301          * play some games, just in case wall doesn't come back
 302          * probably unnecessary, given that wall is careful.
 303          */
 304         if (!setjmp(alarmbuf)) {
 305                 signal(SIGALRM, timeout);
 306                 alarm((u_int)30);
 307                 pclose(pf);
 308                 alarm((u_int)0);
 309                 signal(SIGALRM, SIG_DFL);
 310         }
 311 }
 312
 313 void
 314 timeout(int signo __unused)
 315 {
 316         longjmp(alarmbuf, 1);
 317 }
 318
 319 void
 320 die_you_gravy_sucking_pig_dog(void)
 321 {
 322         char *empty_environ[] = { NULL };
 323
 324         syslog(LOG_NOTICE, "%s by %s: %s",
 325             doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
 326             "shutdown", whom, mbuf);
 327         sleep(2);
 328
 329         printf("\r\nSystem shutdown time has arrived\007\007\r\n");
 330         if (killflg) {
 331                 printf("\rbut you'll have to do it yourself\r\n");
 332                 exit(0);
 333         }
 334 #ifdef DEBUG
 335         if (doreboot)
 336                 printf("reboot");
 337         else if (dohalt)
 338                 printf("halt");
 339         else if (dopower)
 340                 printf("power-down");
 341         if (nosync != NULL)
 342                 printf(" no sync");
 343         printf("\nkill -HUP 1\n");
 344 #else
 345         if (!oflag) {
 346                 kill(1, doreboot ? SIGINT :     /* reboot */
 347                         dohalt ? SIGUSR1 :      /* halt */
 348                         dopower ? SIGUSR2 :     /* power-down */
 349                         SIGTERM);               /* single-user */
 350         } else {
 351                 if (doreboot) {
 352                         execle(_PATH_REBOOT, "reboot", "-l", nosync,
 353                                 NULL, empty_environ);
 354                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 355                                 _PATH_REBOOT);
 356                         warn(_PATH_REBOOT);
 357                 }
 358                 else if (dohalt) {
 359                         execle(_PATH_HALT, "halt", "-l", nosync,
 360                                 NULL, empty_environ);
 361                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 362                                 _PATH_HALT);
 363                         warn(_PATH_HALT);
 364                 }
 365                 else if (dopower) {
 366                         execle(_PATH_HALT, "halt", "-l", "-p", nosync,
 367                                 NULL, empty_environ);
 368                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 369                                 _PATH_HALT);
 370                         warn(_PATH_HALT);
 371                 }
 372                 kill(1, SIGTERM);               /* to single-user */
 373         }
 374 #endif
 375         finish(0);
 376 }
 377
 378 #define ATOI2(p)        (p[0] - '0') * 10 + (p[1] - '0'); p += 2;
 379
 380 void
 381 getoffset(char *timearg)
 382 {
 383         struct tm *lt;
 384         char *p;
 385         time_t now;
 386         int this_year;
 387
 388         time(&now);
 389
 390         if (!strcasecmp(timearg, "now")) {              /* now */
 391                 offset = 0;
 392                 shuttime = now;
 393                 return;
 394         }
 395
 396         if (*timearg == '+') {                          /* +minutes */
 397                 if (!isdigit(*++timearg))
 398                         badtime();
 399                 if ((offset = atoi(timearg) * 60) < 0)
 400                         badtime();
 401                 shuttime = now + offset;
 402                 return;
 403         }
 404
 405         /* handle hh:mm by getting rid of the colon */
 406         for (p = timearg; *p; ++p)
 407                 if (!isascii(*p) || !isdigit(*p)) {
 408                         if (*p == ':' && strlen(p) == 3) {
 409                                 p[0] = p[1];
 410                                 p[1] = p[2];
 411                                 p[2] = '\0';
 412                         }
 413                         else
 414                                 badtime();
 415                 }
 416
 417         unsetenv("TZ");                                 /* OUR timezone */
 418         lt = localtime(&now);                           /* current time val */
 419
 420         switch(strlen(timearg)) {
 421         case 10:
 422                 this_year = lt->tm_year;
 423                 lt->tm_year = ATOI2(timearg);
 424                 /*
 425                  * check if the specified year is in the next century.
 426                  * allow for one year of user error as many people will
 427                  * enter n - 1 at the start of year n.
 428                  */
 429                 if (lt->tm_year < (this_year % 100) - 1)
 430                         lt->tm_year += 100;
 431                 /* adjust for the year 2000 and beyond */
 432                 lt->tm_year += (this_year - (this_year % 100));
 433                 /* FALLTHROUGH */
 434         case 8:
 435                 lt->tm_mon = ATOI2(timearg);
 436                 if (--lt->tm_mon < 0 || lt->tm_mon > 11)
 437                         badtime();
 438                 /* FALLTHROUGH */
 439         case 6:
 440                 lt->tm_mday = ATOI2(timearg);
 441                 if (lt->tm_mday < 1 || lt->tm_mday > 31)
 442                         badtime();
 443                 /* FALLTHROUGH */
 444         case 4:
 445                 lt->tm_hour = ATOI2(timearg);
 446                 if (lt->tm_hour < 0 || lt->tm_hour > 23)
 447                         badtime();
 448                 lt->tm_min = ATOI2(timearg);
 449                 if (lt->tm_min < 0 || lt->tm_min > 59)
 450                         badtime();
 451                 lt->tm_sec = 0;
 452                 if ((shuttime = mktime(lt)) == -1)
 453                         badtime();
 454                 if ((offset = shuttime - now) < 0)
 455                         errx(1, "that time is already past.");
 456                 break;
 457         default:
 458                 badtime();
 459         }
 460 }
 461
 462 #define NOMSG   "\n\nNO LOGINS: System going down at "
 463 void
 464 nolog(void)
 465 {
 466         int logfd;
 467         char *ct;
 468
 469         unlink(_PATH_NOLOGIN);  /* in case linked to another file */
 470         signal(SIGINT, finish);
 471         signal(SIGHUP, finish);
 472         signal(SIGQUIT, finish);
 473         signal(SIGTERM, finish);
 474         if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
 475             0664)) >= 0) {
 476                 write(logfd, NOMSG, sizeof(NOMSG) - 1);
 477                 ct = ctime(&shuttime);
 478                 write(logfd, ct + 11, 5);
 479                 write(logfd, "\n\n", 2);
 480                 write(logfd, mbuf, strlen(mbuf));
 481                 close(logfd);
 482         }
 483 }
 484
 485 void
 486 finish(int signo __unused)
 487 {
 488         if (!killflg)
 489                 unlink(_PATH_NOLOGIN);
 490         exit(0);
 491 }
 492
 493 void
 494 badtime(void)
 495 {
 496         errx(1, "bad time format");
 497 }
 498
 499 void
 500 usage(const char *cp)
 501 {
 502         if (cp != NULL)
 503                 warnx("%s", cp);
 504         fprintf(stderr,
 505             "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]]"
 506             " time [warning-message ...]\n");
 507         exit(1);
 508 }