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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1988, 1990, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)shutdown.c       8.4 (Berkeley) 4/28/95
  35  * $FreeBSD: src/sbin/shutdown/shutdown.c,v 1.21.2.1 2001/07/30 10:38:08 dd Exp $
  36  * $DragonFly: src/sbin/shutdown/shutdown.c,v 1.6 2005/01/02 01:22:49 cpressey Exp $
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/time.h>
  41 #include <sys/resource.h>
  42 #include <sys/syslog.h>
  43
  44 #include <ctype.h>
  45 #include <err.h>
  46 #include <fcntl.h>
  47 #include <pwd.h>
  48 #include <setjmp.h>
  49 #include <signal.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54
  55 #include "pathnames.h"
  56
  57 #ifdef DEBUG
  58 #undef _PATH_NOLOGIN
  59 #define _PATH_NOLOGIN   "./nologin"
  60 #endif
  61
  62 #define H               *60*60
  63 #define M               *60
  64 #define S               *1
  65 #define NOLOG_TIME      5*60
  66 struct interval {
  67         int timeleft, timetowait;
  68 } tlist[] = {
  69         { 10 H,  5 H },
  70         {  5 H,  3 H },
  71         {  2 H,  1 H },
  72         {  1 H, 30 M },
  73         { 30 M, 10 M },
  74         { 20 M, 10 M },
  75         { 10 M,  5 M },
  76         {  5 M,  3 M },
  77         {  2 M,  1 M },
  78         {  1 M, 30 S },
  79         { 30 S, 30 S },
  80         {  0  ,  0   }
  81 };
  82 #undef H
  83 #undef M
  84 #undef S
  85
  86 static time_t offset, shuttime;
  87 static int dohalt, dopower, doreboot, killflg, mbuflen, oflag;
  88 static char mbuf[BUFSIZ];
  89 static const char *nosync, *whom;
  90
  91 void badtime(void);
  92 void die_you_gravy_sucking_pig_dog(void);
  93 void finish(int);
  94 void getoffset(char *);
  95 void loop(void);
  96 void nolog(void);
  97 void timeout(int);
  98 void timewarn(int);
  99 void usage(const char *);
 100
 101 int
 102 main(int argc, char **argv)
 103 {
 104         char *p, *endp;
 105         struct passwd *pw;
 106         int arglen, ch, len, readstdin;
 107
 108 #ifndef DEBUG
 109         if (geteuid())
 110                 errx(1, "NOT super-user");
 111 #endif
 112         nosync = NULL;
 113         readstdin = 0;
 114         while ((ch = getopt(argc, argv, "-hknopr")) != -1)
 115                 switch (ch) {
 116                 case '-':
 117                         readstdin = 1;
 118                         break;
 119                 case 'h':
 120                         dohalt = 1;
 121                         break;
 122                 case 'k':
 123                         killflg = 1;
 124                         break;
 125                 case 'n':
 126                         nosync = "-n";
 127                         break;
 128                 case 'o':
 129                         oflag = 1;
 130                         break;
 131                 case 'p':
 132                         dopower = 1;
 133                         break;
 134                 case 'r':
 135                         doreboot = 1;
 136                         break;
 137                 case '?':
 138                 default:
 139                         usage(NULL);
 140                 }
 141         argc -= optind;
 142         argv += optind;
 143
 144         if (argc < 1)
 145                 usage(NULL);
 146
 147         if (killflg + doreboot + dohalt + dopower > 1)
 148                 usage("incompatible switches -h, -k, -p and -r");
 149
 150         if (oflag && !(dohalt || dopower || doreboot))
 151                 usage("-o requires -h, -p or -r");
 152
 153         if (nosync != NULL && !oflag)
 154                 usage("-n requires -o");
 155
 156         getoffset(*argv++);
 157
 158         if (*argv) {
 159                 for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
 160                         arglen = strlen(*argv);
 161                         if ((len -= arglen) <= 2)
 162                                 break;
 163                         if (p != mbuf)
 164                                 *p++ = ' ';
 165                         memmove(p, *argv, arglen);
 166                         p += arglen;
 167                 }
 168                 *p = '\n';
 169                 *++p = '\0';
 170         }
 171
 172         if (readstdin) {
 173                 p = mbuf;
 174                 endp = mbuf + sizeof(mbuf) - 2;
 175                 for (;;) {
 176                         if (!fgets(p, endp - p + 1, stdin))
 177                                 break;
 178                         for (; *p &&  p < endp; ++p);
 179                         if (p == endp) {
 180                                 *p = '\n';
 181                                 *++p = '\0';
 182                                 break;
 183                         }
 184                 }
 185         }
 186         mbuflen = strlen(mbuf);
 187
 188         if (offset)
 189                 printf("Shutdown at %.24s.\n", ctime(&shuttime));
 190         else
 191                 printf("Shutdown NOW!\n");
 192
 193         if (!(whom = getlogin()))
 194                 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 195
 196 #ifdef DEBUG
 197         putc('\n', stdout);
 198 #else
 199         setpriority(PRIO_PROCESS, 0, PRIO_MIN);
 200         {
 201                 int forkpid;
 202
 203                 forkpid = fork();
 204                 if (forkpid == -1)
 205                         err(1, "fork");
 206                 if (forkpid)
 207                         errx(0, "[pid %d]", forkpid);
 208         }
 209         setsid();
 210 #endif
 211         openlog("shutdown", LOG_CONS, LOG_AUTH);
 212         loop();
 213         return(0);
 214 }
 215
 216 void
 217 loop(void)
 218 {
 219         struct interval *tp;
 220         u_int sltime;
 221         int logged;
 222
 223         if (offset <= NOLOG_TIME) {
 224                 logged = 1;
 225                 nolog();
 226         }
 227         else
 228                 logged = 0;
 229         tp = tlist;
 230         if (tp->timeleft < offset)
 231                 sleep((u_int)(offset - tp->timeleft));
 232         else {
 233                 while (tp->timeleft && offset < tp->timeleft)
 234                         ++tp;
 235                 /*
 236                  * Warn now, if going to sleep more than a fifth of
 237                  * the next wait time.
 238                  */
 239                 if ((sltime = offset - tp->timeleft)) {
 240                         if (sltime > (u_int)(tp->timetowait / 5))
 241                                 timewarn(offset);
 242                         sleep(sltime);
 243                 }
 244         }
 245         for (;; ++tp) {
 246                 timewarn(tp->timeleft);
 247                 if (!logged && tp->timeleft <= NOLOG_TIME) {
 248                         logged = 1;
 249                         nolog();
 250                 }
 251                 sleep((u_int)tp->timetowait);
 252                 if (!tp->timeleft)
 253                         break;
 254         }
 255         die_you_gravy_sucking_pig_dog();
 256 }
 257
 258 static jmp_buf alarmbuf;
 259
 260 static const char *restricted_environ[] = {
 261         "PATH=" _PATH_STDPATH,
 262         NULL
 263 };
 264
 265 extern const char **environ;
 266
 267 void
 268 timewarn(int timeleft)
 269 {
 270         static int first;
 271         static char hostname[MAXHOSTNAMELEN + 1];
 272         FILE *pf;
 273         char wcmd[MAXPATHLEN + 4];
 274
 275         if (!first++)
 276                 gethostname(hostname, sizeof(hostname));
 277
 278         /* undoc -n option to wall suppresses normal wall banner */
 279         snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
 280         environ = restricted_environ;
 281         if (!(pf = popen(wcmd, "w"))) {
 282                 syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
 283                 return;
 284         }
 285
 286         fprintf(pf,
 287             "\007*** %sSystem shutdown message from %s@%s ***\007\n",
 288             timeleft ? "": "FINAL ", whom, hostname);
 289
 290         if (timeleft > 10*60)
 291                 fprintf(pf, "System going down at %5.5s\n\n",
 292                     ctime(&shuttime) + 11);
 293         else if (timeleft > 59)
 294                 fprintf(pf, "System going down in %d minute%s\n\n",
 295                     timeleft / 60, (timeleft > 60) ? "s" : "");
 296         else if (timeleft)
 297                 fprintf(pf, "System going down in 30 seconds\n\n");
 298         else
 299                 fprintf(pf, "System going down IMMEDIATELY\n\n");
 300
 301         if (mbuflen)
 302                 fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
 303
 304         /*
 305          * play some games, just in case wall doesn't come back
 306          * probably unnecessary, given that wall is careful.
 307          */
 308         if (!setjmp(alarmbuf)) {
 309                 signal(SIGALRM, timeout);
 310                 alarm((u_int)30);
 311                 pclose(pf);
 312                 alarm((u_int)0);
 313                 signal(SIGALRM, SIG_DFL);
 314         }
 315 }
 316
 317 void
 318 timeout(int signo __unused)
 319 {
 320         longjmp(alarmbuf, 1);
 321 }
 322
 323 void
 324 die_you_gravy_sucking_pig_dog(void)
 325 {
 326         char *empty_environ[] = { NULL };
 327
 328         syslog(LOG_NOTICE, "%s by %s: %s",
 329             doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
 330             "shutdown", whom, mbuf);
 331         sleep(2);
 332
 333         printf("\r\nSystem shutdown time has arrived\007\007\r\n");
 334         if (killflg) {
 335                 printf("\rbut you'll have to do it yourself\r\n");
 336                 exit(0);
 337         }
 338 #ifdef DEBUG
 339         if (doreboot)
 340                 printf("reboot");
 341         else if (dohalt)
 342                 printf("halt");
 343         else if (dopower)
 344                 printf("power-down");
 345         if (nosync != NULL)
 346                 printf(" no sync");
 347         printf("\nkill -HUP 1\n");
 348 #else
 349         if (!oflag) {
 350                 kill(1, doreboot ? SIGINT :     /* reboot */
 351                         dohalt ? SIGUSR1 :      /* halt */
 352                         dopower ? SIGUSR2 :     /* power-down */
 353                         SIGTERM);               /* single-user */
 354         } else {
 355                 if (doreboot) {
 356                         execle(_PATH_REBOOT, "reboot", "-l", nosync,
 357                                 NULL, empty_environ);
 358                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 359                                 _PATH_REBOOT);
 360                         warn(_PATH_REBOOT);
 361                 }
 362                 else if (dohalt) {
 363                         execle(_PATH_HALT, "halt", "-l", nosync,
 364                                 NULL, empty_environ);
 365                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 366                                 _PATH_HALT);
 367                         warn(_PATH_HALT);
 368                 }
 369                 else if (dopower) {
 370                         execle(_PATH_HALT, "halt", "-l", "-p", nosync,
 371                                 NULL, empty_environ);
 372                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 373                                 _PATH_HALT);
 374                         warn(_PATH_HALT);
 375                 }
 376                 kill(1, SIGTERM);               /* to single-user */
 377         }
 378 #endif
 379         finish(0);
 380 }
 381
 382 #define ATOI2(p)        (p[0] - '0') * 10 + (p[1] - '0'); p += 2;
 383
 384 void
 385 getoffset(char *timearg)
 386 {
 387         struct tm *lt;
 388         char *p;
 389         time_t now;
 390         int this_year;
 391
 392         time(&now);
 393
 394         if (!strcasecmp(timearg, "now")) {              /* now */
 395                 offset = 0;
 396                 shuttime = now;
 397                 return;
 398         }
 399
 400         if (*timearg == '+') {                          /* +minutes */
 401                 if (!isdigit(*++timearg))
 402                         badtime();
 403                 if ((offset = atoi(timearg) * 60) < 0)
 404                         badtime();
 405                 shuttime = now + offset;
 406                 return;
 407         }
 408
 409         /* handle hh:mm by getting rid of the colon */
 410         for (p = timearg; *p; ++p)
 411                 if (!isascii(*p) || !isdigit(*p)) {
 412                         if (*p == ':' && strlen(p) == 3) {
 413                                 p[0] = p[1];
 414                                 p[1] = p[2];
 415                                 p[2] = '\0';
 416                         }
 417                         else
 418                                 badtime();
 419                 }
 420
 421         unsetenv("TZ");                                 /* OUR timezone */
 422         lt = localtime(&now);                           /* current time val */
 423
 424         switch(strlen(timearg)) {
 425         case 10:
 426                 this_year = lt->tm_year;
 427                 lt->tm_year = ATOI2(timearg);
 428                 /*
 429                  * check if the specified year is in the next century.
 430                  * allow for one year of user error as many people will
 431                  * enter n - 1 at the start of year n.
 432                  */
 433                 if (lt->tm_year < (this_year % 100) - 1)
 434                         lt->tm_year += 100;
 435                 /* adjust for the year 2000 and beyond */
 436                 lt->tm_year += (this_year - (this_year % 100));
 437                 /* FALLTHROUGH */
 438         case 8:
 439                 lt->tm_mon = ATOI2(timearg);
 440                 if (--lt->tm_mon < 0 || lt->tm_mon > 11)
 441                         badtime();
 442                 /* FALLTHROUGH */
 443         case 6:
 444                 lt->tm_mday = ATOI2(timearg);
 445                 if (lt->tm_mday < 1 || lt->tm_mday > 31)
 446                         badtime();
 447                 /* FALLTHROUGH */
 448         case 4:
 449                 lt->tm_hour = ATOI2(timearg);
 450                 if (lt->tm_hour < 0 || lt->tm_hour > 23)
 451                         badtime();
 452                 lt->tm_min = ATOI2(timearg);
 453                 if (lt->tm_min < 0 || lt->tm_min > 59)
 454                         badtime();
 455                 lt->tm_sec = 0;
 456                 if ((shuttime = mktime(lt)) == -1)
 457                         badtime();
 458                 if ((offset = shuttime - now) < 0)
 459                         errx(1, "that time is already past.");
 460                 break;
 461         default:
 462                 badtime();
 463         }
 464 }
 465
 466 #define NOMSG   "\n\nNO LOGINS: System going down at "
 467 void
 468 nolog(void)
 469 {
 470         int logfd;
 471         char *ct;
 472
 473         unlink(_PATH_NOLOGIN);  /* in case linked to another file */
 474         signal(SIGINT, finish);
 475         signal(SIGHUP, finish);
 476         signal(SIGQUIT, finish);
 477         signal(SIGTERM, finish);
 478         if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
 479             0664)) >= 0) {
 480                 write(logfd, NOMSG, sizeof(NOMSG) - 1);
 481                 ct = ctime(&shuttime);
 482                 write(logfd, ct + 11, 5);
 483                 write(logfd, "\n\n", 2);
 484                 write(logfd, mbuf, strlen(mbuf));
 485                 close(logfd);
 486         }
 487 }
 488
 489 void
 490 finish(int signo __unused)
 491 {
 492         if (!killflg)
 493                 unlink(_PATH_NOLOGIN);
 494         exit(0);
 495 }
 496
 497 void
 498 badtime(void)
 499 {
 500         errx(1, "bad time format");
 501 }
 502
 503 void
 504 usage(const char *cp)
 505 {
 506         if (cp != NULL)
 507                 warnx("%s", cp);
 508         fprintf(stderr,
 509             "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]]"
 510             " time [warning-message ...]\n");
 511         exit(1);
 512 }