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 <fcntl.h>
  42 #include <pwd.h>
  43 #include <setjmp.h>
  44 #include <signal.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #include "pathnames.h"
  51
  52 #ifdef DEBUG
  53 #undef _PATH_NOLOGIN
  54 #define _PATH_NOLOGIN   "./nologin"
  55 #endif
  56
  57 #define H               *60*60
  58 #define M               *60
  59 #define S               *1
  60 #define NOLOG_TIME      5*60
  61 static struct interval {
  62         int timeleft, timetowait;
  63 } tlist[] = {
  64         { 10 H,  5 H },
  65         {  5 H,  3 H },
  66         {  2 H,  1 H },
  67         {  1 H, 30 M },
  68         { 30 M, 10 M },
  69         { 20 M, 10 M },
  70         { 10 M,  5 M },
  71         {  5 M,  3 M },
  72         {  2 M,  1 M },
  73         {  1 M, 30 S },
  74         { 30 S, 30 S },
  75         {  0  ,  0   }
  76 };
  77 #undef H
  78 #undef M
  79 #undef S
  80
  81 static time_t offset, shuttime;
  82 static int dohalt, dopower, doreboot, killflg, mbuflen, oflag;
  83 static char mbuf[BUFSIZ];
  84 static const char *nosync, *whom;
  85
  86 static void badtime(void);
  87 static void die_you_gravy_sucking_pig_dog(void);
  88 static void finish(int);
  89 static void getoffset(char *);
  90 static void loop(void);
  91 static void nolog(void);
  92 static void timeout(int);
  93 static void timewarn(int);
  94 static void usage(const char *);
  95
  96 extern const char **environ;
  97
  98 int
  99 main(int argc, char **argv)
 100 {
 101         char *p, *endp;
 102         struct passwd *pw;
 103         int arglen, ch, len, readstdin;
 104
 105 #ifndef DEBUG
 106         if (geteuid())
 107                 errx(1, "NOT super-user");
 108 #endif
 109
 110         nosync = NULL;
 111         readstdin = 0;
 112
 113         /*
 114          * Test for the special case where the utility is called as
 115          * "poweroff", for which it runs 'shutdown -p now'.
 116          */
 117         if ((p = strrchr(argv[0], '/')) == NULL)
 118                 p = argv[0];
 119         else
 120                 ++p;
 121         if (strcmp(p, "poweroff") == 0) {
 122                 if (getopt(argc, argv, "") != -1)
 123                         usage(NULL);
 124                 argc -= optind;
 125                 argv += optind;
 126                 if (argc != 0)
 127                         usage(NULL);
 128                 dopower = 1;
 129                 offset = 0;
 130                 (void)time(&shuttime);
 131                 goto poweroff;
 132         }
 133
 134         while ((ch = getopt(argc, argv, "-hknopr")) != -1)
 135                 switch (ch) {
 136                 case '-':
 137                         readstdin = 1;
 138                         break;
 139                 case 'h':
 140                         dohalt = 1;
 141                         break;
 142                 case 'k':
 143                         killflg = 1;
 144                         break;
 145                 case 'n':
 146                         nosync = "-n";
 147                         break;
 148                 case 'o':
 149                         oflag = 1;
 150                         break;
 151                 case 'p':
 152                         dopower = 1;
 153                         break;
 154                 case 'r':
 155                         doreboot = 1;
 156                         break;
 157                 case '?':
 158                 default:
 159                         usage(NULL);
 160                 }
 161         argc -= optind;
 162         argv += optind;
 163
 164         if (argc < 1)
 165                 usage(NULL);
 166
 167         if (killflg + doreboot + dohalt + dopower > 1)
 168                 usage("incompatible switches -h, -k, -p and -r");
 169
 170         if (oflag && !(dohalt || dopower || doreboot))
 171                 usage("-o requires -h, -p or -r");
 172
 173         if (nosync != NULL && !oflag)
 174                 usage("-n requires -o");
 175
 176         getoffset(*argv++);
 177
 178 poweroff:
 179         if (*argv) {
 180                 for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
 181                         arglen = strlen(*argv);
 182                         if ((len -= arglen) <= 2)
 183                                 break;
 184                         if (p != mbuf)
 185                                 *p++ = ' ';
 186                         memmove(p, *argv, arglen);
 187                         p += arglen;
 188                 }
 189                 *p = '\n';
 190                 *++p = '\0';
 191         }
 192
 193         if (readstdin) {
 194                 p = mbuf;
 195                 endp = mbuf + sizeof(mbuf) - 2;
 196                 for (;;) {
 197                         if (!fgets(p, endp - p + 1, stdin))
 198                                 break;
 199                         for (; *p &&  p < endp; ++p);
 200                         if (p == endp) {
 201                                 *p = '\n';
 202                                 *++p = '\0';
 203                                 break;
 204                         }
 205                 }
 206         }
 207         mbuflen = strlen(mbuf);
 208
 209         if (offset)
 210                 printf("Shutdown at %.24s.\n", ctime(&shuttime));
 211         else
 212                 printf("Shutdown NOW!\n");
 213
 214         if (!(whom = getlogin()))
 215                 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 216
 217 #ifdef DEBUG
 218         putc('\n', stdout);
 219 #else
 220         setpriority(PRIO_PROCESS, 0, PRIO_MIN);
 221         {
 222                 int forkpid;
 223
 224                 forkpid = fork();
 225                 if (forkpid == -1)
 226                         err(1, "fork");
 227                 if (forkpid)
 228                         errx(0, "[pid %d]", forkpid);
 229         }
 230         setsid();
 231 #endif
 232         openlog("shutdown", LOG_CONS, LOG_AUTH);
 233         loop();
 234         return(0);
 235 }
 236
 237 static void
 238 loop(void)
 239 {
 240         struct interval *tp;
 241         u_int sltime;
 242         int logged;
 243
 244         if (offset <= NOLOG_TIME) {
 245                 logged = 1;
 246                 nolog();
 247         }
 248         else
 249                 logged = 0;
 250         tp = tlist;
 251         if (tp->timeleft < offset)
 252                 sleep((u_int)(offset - tp->timeleft));
 253         else {
 254                 while (tp->timeleft && offset < tp->timeleft)
 255                         ++tp;
 256                 /*
 257                  * Warn now, if going to sleep more than a fifth of
 258                  * the next wait time.
 259                  */
 260                 if ((sltime = offset - tp->timeleft)) {
 261                         if (sltime > (u_int)(tp->timetowait / 5))
 262                                 timewarn(offset);
 263                         sleep(sltime);
 264                 }
 265         }
 266         for (;; ++tp) {
 267                 timewarn(tp->timeleft);
 268                 if (!logged && tp->timeleft <= NOLOG_TIME) {
 269                         logged = 1;
 270                         nolog();
 271                 }
 272                 sleep((u_int)tp->timetowait);
 273                 if (!tp->timeleft)
 274                         break;
 275         }
 276         die_you_gravy_sucking_pig_dog();
 277 }
 278
 279 static jmp_buf alarmbuf;
 280
 281 static const char *restricted_environ[] = {
 282         "PATH=" _PATH_STDPATH,
 283         NULL
 284 };
 285
 286 static void
 287 timewarn(int timeleft)
 288 {
 289         static int first;
 290         static char hostname[MAXHOSTNAMELEN + 1];
 291         FILE *pf;
 292         char wcmd[MAXPATHLEN + 4];
 293
 294         if (!first++)
 295                 gethostname(hostname, sizeof(hostname));
 296
 297         /* undoc -n option to wall suppresses normal wall banner */
 298         snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
 299         environ = restricted_environ;
 300         if (!(pf = popen(wcmd, "w"))) {
 301                 syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
 302                 return;
 303         }
 304
 305         fprintf(pf,
 306             "\007*** %sSystem shutdown message from %s@%s ***\007\n",
 307             timeleft ? "": "FINAL ", whom, hostname);
 308
 309         if (timeleft > 10*60)
 310                 fprintf(pf, "System going down at %5.5s\n\n",
 311                     ctime(&shuttime) + 11);
 312         else if (timeleft > 59)
 313                 fprintf(pf, "System going down in %d minute%s\n\n",
 314                     timeleft / 60, (timeleft > 60) ? "s" : "");
 315         else if (timeleft)
 316                 fprintf(pf, "System going down in 30 seconds\n\n");
 317         else
 318                 fprintf(pf, "System going down IMMEDIATELY\n\n");
 319
 320         if (mbuflen)
 321                 fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
 322
 323         /*
 324          * play some games, just in case wall doesn't come back
 325          * probably unnecessary, given that wall is careful.
 326          */
 327         if (!setjmp(alarmbuf)) {
 328                 signal(SIGALRM, timeout);
 329                 alarm((u_int)30);
 330                 pclose(pf);
 331                 alarm((u_int)0);
 332                 signal(SIGALRM, SIG_DFL);
 333         }
 334 }
 335
 336 static void
 337 timeout(int signo __unused)
 338 {
 339         longjmp(alarmbuf, 1);
 340 }
 341
 342 static void
 343 die_you_gravy_sucking_pig_dog(void)
 344 {
 345         char *empty_environ[] = { NULL };
 346
 347         syslog(LOG_NOTICE, "%s by %s: %s",
 348             doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
 349             "shutdown", whom, mbuf);
 350         sleep(2);
 351
 352         printf("\r\nSystem shutdown time has arrived\007\007\r\n");
 353         if (killflg) {
 354                 printf("\rbut you'll have to do it yourself\r\n");
 355                 exit(0);
 356         }
 357 #ifdef DEBUG
 358         if (doreboot)
 359                 printf("reboot");
 360         else if (dohalt)
 361                 printf("halt");
 362         else if (dopower)
 363                 printf("power-down");
 364         if (nosync != NULL)
 365                 printf(" no sync");
 366         printf("\nkill -HUP 1\n");
 367 #else
 368         if (!oflag) {
 369                 kill(1, doreboot ? SIGINT :     /* reboot */
 370                         dohalt ? SIGUSR1 :      /* halt */
 371                         dopower ? SIGUSR2 :     /* power-down */
 372                         SIGTERM);               /* single-user */
 373         } else {
 374                 if (doreboot) {
 375                         execle(_PATH_REBOOT, "reboot", "-l", nosync,
 376                                 NULL, empty_environ);
 377                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 378                                 _PATH_REBOOT);
 379                         warn(_PATH_REBOOT);
 380                 }
 381                 else if (dohalt) {
 382                         execle(_PATH_HALT, "halt", "-l", nosync,
 383                                 NULL, empty_environ);
 384                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 385                                 _PATH_HALT);
 386                         warn(_PATH_HALT);
 387                 }
 388                 else if (dopower) {
 389                         execle(_PATH_HALT, "halt", "-l", "-p", nosync,
 390                                 NULL, empty_environ);
 391                         syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
 392                                 _PATH_HALT);
 393                         warn(_PATH_HALT);
 394                 }
 395                 kill(1, SIGTERM);               /* to single-user */
 396         }
 397 #endif
 398         finish(0);
 399 }
 400
 401 #define ATOI2(p)        (p[0] - '0') * 10 + (p[1] - '0'); p += 2;
 402
 403 static void
 404 getoffset(char *timearg)
 405 {
 406         struct tm *lt;
 407         char *p;
 408         time_t now;
 409         int this_year;
 410
 411         time(&now);
 412
 413         if (!strcasecmp(timearg, "now")) {              /* now */
 414                 offset = 0;
 415                 shuttime = now;
 416                 return;
 417         }
 418
 419         if (*timearg == '+') {                          /* +minutes */
 420                 if (!isdigit(*++timearg))
 421                         badtime();
 422                 if ((offset = atoi(timearg) * 60) < 0)
 423                         badtime();
 424                 shuttime = now + offset;
 425                 return;
 426         }
 427
 428         /* handle hh:mm by getting rid of the colon */
 429         for (p = timearg; *p; ++p)
 430                 if (!isascii(*p) || !isdigit(*p)) {
 431                         if (*p == ':' && strlen(p) == 3) {
 432                                 p[0] = p[1];
 433                                 p[1] = p[2];
 434                                 p[2] = '\0';
 435                         }
 436                         else
 437                                 badtime();
 438                 }
 439
 440         unsetenv("TZ");                                 /* OUR timezone */
 441         lt = localtime(&now);                           /* current time val */
 442
 443         switch(strlen(timearg)) {
 444         case 10:
 445                 this_year = lt->tm_year;
 446                 lt->tm_year = ATOI2(timearg);
 447                 /*
 448                  * check if the specified year is in the next century.
 449                  * allow for one year of user error as many people will
 450                  * enter n - 1 at the start of year n.
 451                  */
 452                 if (lt->tm_year < (this_year % 100) - 1)
 453                         lt->tm_year += 100;
 454                 /* adjust for the year 2000 and beyond */
 455                 lt->tm_year += (this_year - (this_year % 100));
 456                 /* FALLTHROUGH */
 457         case 8:
 458                 lt->tm_mon = ATOI2(timearg);
 459                 if (--lt->tm_mon < 0 || lt->tm_mon > 11)
 460                         badtime();
 461                 /* FALLTHROUGH */
 462         case 6:
 463                 lt->tm_mday = ATOI2(timearg);
 464                 if (lt->tm_mday < 1 || lt->tm_mday > 31)
 465                         badtime();
 466                 /* FALLTHROUGH */
 467         case 4:
 468                 lt->tm_hour = ATOI2(timearg);
 469                 if (lt->tm_hour < 0 || lt->tm_hour > 23)
 470                         badtime();
 471                 lt->tm_min = ATOI2(timearg);
 472                 if (lt->tm_min < 0 || lt->tm_min > 59)
 473                         badtime();
 474                 lt->tm_sec = 0;
 475                 if ((shuttime = mktime(lt)) == -1)
 476                         badtime();
 477                 if ((offset = shuttime - now) < 0)
 478                         errx(1, "that time is already past.");
 479                 break;
 480         default:
 481                 badtime();
 482         }
 483 }
 484
 485 #define NOMSG   "\n\nNO LOGINS: System going down at "
 486 static void
 487 nolog(void)
 488 {
 489         int logfd;
 490         char *ct;
 491
 492         unlink(_PATH_NOLOGIN);  /* in case linked to another file */
 493         signal(SIGINT, finish);
 494         signal(SIGHUP, finish);
 495         signal(SIGQUIT, finish);
 496         signal(SIGTERM, finish);
 497         if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
 498             0664)) >= 0) {
 499                 write(logfd, NOMSG, sizeof(NOMSG) - 1);
 500                 ct = ctime(&shuttime);
 501                 write(logfd, ct + 11, 5);
 502                 write(logfd, "\n\n", 2);
 503                 write(logfd, mbuf, strlen(mbuf));
 504                 close(logfd);
 505         }
 506 }
 507
 508 static void
 509 finish(int signo __unused)
 510 {
 511         if (!killflg)
 512                 unlink(_PATH_NOLOGIN);
 513         exit(0);
 514 }
 515
 516 static void
 517 badtime(void)
 518 {
 519         errx(1, "bad time format");
 520 }
 521
 522 static void
 523 usage(const char *cp)
 524 {
 525         if (cp != NULL)
 526                 warnx("%s", cp);
 527         fprintf(stderr,
 528             "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]]"
 529             " time [warning-message ...]\n"
 530             "       poweroff\n");
 531         exit(1);
 532 }