freebsd-dev/sbin/shutdown/shutdown.c
Alexander Langer f6faa785f2 Pass an actual empty environment to execle() as per POSIX rather than
rely on undocumented behavior.

The following fixes were obtained from OpenBSD:

  o -Wall fixes to tlist array initialization and assignment used
    as truth value.
  o Use a restricted environment.
  o Improved error message when shutdown fails to exec reboot or halt.
1998-01-10 20:11:06 +00:00

486 lines
11 KiB
C

/*
* Copyright (c) 1988, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: shutdown.c,v 1.11 1998/01/08 20:05:45 alex Exp $
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1988, 1990, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)shutdown.c 8.2 (Berkeley) 2/16/94";
#endif /* not lint */
#include <sys/param.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/syslog.h>
#include <ctype.h>
#include <fcntl.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include "pathnames.h"
#ifdef DEBUG
#undef _PATH_NOLOGIN
#define _PATH_NOLOGIN "./nologin"
#endif
#define H *60*60
#define M *60
#define S *1
#define NOLOG_TIME 5*60
struct interval {
int timeleft, timetowait;
} tlist[] = {
{ 10 H, 5 H },
{ 5 H, 3 H },
{ 2 H, 1 H },
{ 1 H, 30 M },
{ 30 M, 10 M },
{ 20 M, 10 M },
{ 10 M, 5 M },
{ 5 M, 3 M },
{ 2 M, 1 M },
{ 1 M, 30 S },
{ 30 S, 30 S },
{ 0 , 0 }
};
#undef H
#undef M
#undef S
static time_t offset, shuttime;
static int dohalt, doreboot, killflg, mbuflen;
static char *nosync, *whom, mbuf[BUFSIZ];
void badtime __P((void));
void die_you_gravy_sucking_pig_dog __P((void));
void finish __P((int));
void getoffset __P((char *));
void loop __P((void));
void nolog __P((void));
void timeout __P((int));
void timewarn __P((int));
void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
extern int optind;
register char *p, *endp;
struct passwd *pw;
int arglen, ch, len, readstdin;
#ifndef DEBUG
if (geteuid())
errx(1, "NOT super-user");
#endif
nosync = NULL;
readstdin = 0;
while ((ch = getopt(argc, argv, "-hknr")) != -1)
switch (ch) {
case '-':
readstdin = 1;
break;
case 'h':
dohalt = 1;
break;
case 'k':
killflg = 1;
break;
case 'n':
nosync = "-n";
break;
case 'r':
doreboot = 1;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc < 1)
usage();
if (doreboot && dohalt) {
warnx("incompatible switches -h and -r.");
usage();
}
getoffset(*argv++);
if (*argv) {
for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
arglen = strlen(*argv);
if ((len -= arglen) <= 2)
break;
if (p != mbuf)
*p++ = ' ';
bcopy(*argv, p, arglen);
p += arglen;
}
*p = '\n';
*++p = '\0';
}
if (readstdin) {
p = mbuf;
endp = mbuf + sizeof(mbuf) - 2;
for (;;) {
if (!fgets(p, endp - p + 1, stdin))
break;
for (; *p && p < endp; ++p);
if (p == endp) {
*p = '\n';
*++p = '\0';
break;
}
}
}
mbuflen = strlen(mbuf);
if (offset)
(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
else
(void)printf("Shutdown NOW!\n");
if (!(whom = getlogin()))
whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
#ifdef DEBUG
(void)putc('\n', stdout);
#else
(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
{
int forkpid;
forkpid = fork();
if (forkpid == -1)
err(1, "fork");
if (forkpid)
errx(0, "[pid %d]", forkpid);
}
setsid();
#endif
openlog("shutdown", LOG_CONS, LOG_AUTH);
loop();
/* NOTREACHED */
}
void
loop()
{
struct interval *tp;
u_int sltime;
int logged;
if (offset <= NOLOG_TIME) {
logged = 1;
nolog();
}
else
logged = 0;
tp = tlist;
if (tp->timeleft < offset)
(void)sleep((u_int)(offset - tp->timeleft));
else {
while (offset < tp->timeleft)
++tp;
/*
* Warn now, if going to sleep more than a fifth of
* the next wait time.
*/
if ((sltime = offset - tp->timeleft)) {
if (sltime > tp->timetowait / 5)
timewarn(offset);
(void)sleep(sltime);
}
}
for (;; ++tp) {
timewarn(tp->timeleft);
if (!logged && tp->timeleft <= NOLOG_TIME) {
logged = 1;
nolog();
}
(void)sleep((u_int)tp->timetowait);
if (!tp->timeleft)
break;
}
die_you_gravy_sucking_pig_dog();
}
static jmp_buf alarmbuf;
static char *restricted_environ[] = {
"PATH=" _PATH_STDPATH,
NULL
};
void
timewarn(timeleft)
int timeleft;
{
static int first;
static char hostname[MAXHOSTNAMELEN + 1];
FILE *pf;
char wcmd[MAXPATHLEN + 4];
extern char **environ;
if (!first++)
(void)gethostname(hostname, sizeof(hostname));
/* undoc -n option to wall suppresses normal wall banner */
(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
environ = restricted_environ;
if (!(pf = popen(wcmd, "w"))) {
syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
return;
}
(void)fprintf(pf,
"\007*** %sSystem shutdown message from %s@%s ***\007\n",
timeleft ? "": "FINAL ", whom, hostname);
if (timeleft > 10*60)
(void)fprintf(pf, "System going down at %5.5s\n\n",
ctime(&shuttime) + 11);
else if (timeleft > 59)
(void)fprintf(pf, "System going down in %d minute%s\n\n",
timeleft / 60, (timeleft > 60) ? "s" : "");
else if (timeleft)
(void)fprintf(pf, "System going down in 30 seconds\n\n");
else
(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
if (mbuflen)
(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
/*
* play some games, just in case wall doesn't come back
* probably unecessary, given that wall is careful.
*/
if (!setjmp(alarmbuf)) {
(void)signal(SIGALRM, timeout);
(void)alarm((u_int)30);
(void)pclose(pf);
(void)alarm((u_int)0);
(void)signal(SIGALRM, SIG_DFL);
}
}
void
timeout(signo)
int signo;
{
longjmp(alarmbuf, 1);
}
void
die_you_gravy_sucking_pig_dog()
{
char *empty_environ[] = { NULL };
syslog(LOG_NOTICE, "%s by %s: %s",
doreboot ? "reboot" : dohalt ? "halt" : "shutdown", whom, mbuf);
(void)sleep(2);
(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
if (killflg) {
(void)printf("\rbut you'll have to do it yourself\r\n");
exit(0);
}
#ifdef DEBUG
if (doreboot)
(void)printf("reboot");
else if (dohalt)
(void)printf("halt");
if (nosync)
(void)printf(" no sync");
(void)printf("\nkill -HUP 1\n");
#else
if (doreboot) {
execle(_PATH_REBOOT, "reboot", "-l", nosync,
(char *)NULL, empty_environ);
syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_REBOOT);
warn(_PATH_REBOOT);
}
else if (dohalt) {
execle(_PATH_HALT, "halt", "-l", nosync,
(char *)NULL, empty_environ);
syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_HALT);
warn(_PATH_HALT);
}
(void)kill(1, SIGTERM); /* to single user */
#endif
finish(0);
}
#define ATOI2(p) (p[0] - '0') * 10 + (p[1] - '0'); p += 2;
void
getoffset(timearg)
register char *timearg;
{
register struct tm *lt;
register char *p;
time_t now;
int this_year;
if (!strcasecmp(timearg, "now")) { /* now */
offset = 0;
return;
}
(void)time(&now);
if (*timearg == '+') { /* +minutes */
if (!isdigit(*++timearg))
badtime();
offset = atoi(timearg) * 60;
shuttime = now + offset;
return;
}
/* handle hh:mm by getting rid of the colon */
for (p = timearg; *p; ++p)
if (!isascii(*p) || !isdigit(*p))
if (*p == ':' && strlen(p) == 3) {
p[0] = p[1];
p[1] = p[2];
p[2] = '\0';
}
else
badtime();
unsetenv("TZ"); /* OUR timezone */
lt = localtime(&now); /* current time val */
switch(strlen(timearg)) {
case 10:
this_year = lt->tm_year;
lt->tm_year = ATOI2(timearg);
/*
* check if the specified year is in the next century.
* allow for one year of user error as many people will
* enter n - 1 at the start of year n.
*/
if (lt->tm_year < (this_year % 100) - 1)
lt->tm_year += 100;
/* adjust for the year 2000 and beyond */
lt->tm_year += (this_year - (this_year % 100));
/* FALLTHROUGH */
case 8:
lt->tm_mon = ATOI2(timearg);
if (--lt->tm_mon < 0 || lt->tm_mon > 11)
badtime();
/* FALLTHROUGH */
case 6:
lt->tm_mday = ATOI2(timearg);
if (lt->tm_mday < 1 || lt->tm_mday > 31)
badtime();
/* FALLTHROUGH */
case 4:
lt->tm_hour = ATOI2(timearg);
if (lt->tm_hour < 0 || lt->tm_hour > 23)
badtime();
lt->tm_min = ATOI2(timearg);
if (lt->tm_min < 0 || lt->tm_min > 59)
badtime();
lt->tm_sec = 0;
if ((shuttime = mktime(lt)) == -1)
badtime();
if ((offset = shuttime - now) < 0)
errx(1, "that time is already past.");
break;
default:
badtime();
}
}
#define NOMSG "\n\nNO LOGINS: System going down at "
void
nolog()
{
int logfd;
char *ct;
(void)unlink(_PATH_NOLOGIN); /* in case linked to another file */
(void)signal(SIGINT, finish);
(void)signal(SIGHUP, finish);
(void)signal(SIGQUIT, finish);
(void)signal(SIGTERM, finish);
if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
0664)) >= 0) {
(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
ct = ctime(&shuttime);
(void)write(logfd, ct + 11, 5);
(void)write(logfd, "\n\n", 2);
(void)write(logfd, mbuf, strlen(mbuf));
(void)close(logfd);
}
}
void
finish(signo)
int signo;
{
(void)unlink(_PATH_NOLOGIN);
exit(0);
}
void
badtime()
{
errx(1, "bad time format.");
}
void
usage()
{
fprintf(stderr, "usage: shutdown [-hknr] shutdowntime [ message ]\n");
exit(1);
}