/*      $NetBSD: shutdown.c,v 1.60 2026/05/11 23:21:07 kre Exp $        */

/*
 * 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. 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1990, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)shutdown.c  8.4 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: shutdown.c,v 1.60 2026/05/11 23:21:07 kre Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/syslog.h>

#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>
#include <unistd.h>
#include <errno.h>

#include "pathnames.h"

#ifdef DEBUG
#undef _PATH_NOLOGIN
#define _PATH_NOLOGIN   "./nologin"
#undef _PATH_FASTBOOT
#define _PATH_FASTBOOT  "./fastboot"
#endif

#define H               *60*60
#define M               *60
#define S               *1
#define NOLOG_TIME      5*60
static const struct interval {
        time_t 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 dofast, dohalt, doreboot, kidding, nofork, nosync, dodump;
static size_t mbuflen;
static int dopowerdown;
static int dodebug, dosilent, doverbose;
static const char *whom;
static char mbuf[BUFSIZ];
static char *bootstr;

static void badtime(void) __dead;
static void die_you_gravy_sucking_pig_dog(void) __dead;
static void doitfast(void);
static void dorcshutdown(const char *what);
static void finish(int) __dead;
static void getoffset(char *);
static void loop(void) __dead;
static void nolog(void);
static void timeout(int) __dead;
static void timewarn(time_t);
static void usage(void) __dead;

int
main(int argc, char *argv[])
{
        char *p, *endp;
        struct passwd *pw;
        size_t arglen, len;
        int ch;

        (void)setprogname(argv[0]);
#ifndef DEBUG
        if (geteuid())
                errx(1, "%s: Not super-user", strerror(EPERM));
#endif
        while ((ch = getopt(argc, argv, "b:Ddfhknprvxz")) != -1)
                switch (ch) {
                case 'b':
                        bootstr = optarg;
                        break;
                case 'd':
                        dodump = 1;
                        break;
                case 'D':
                        nofork = 1;
                        break;
                case 'f':
                        dofast = 1;
                        break;
                case 'p':
                        dopowerdown = 1;
                        /* FALLTHROUGH */
                case 'h':
                        dohalt = 1;
                        break;
                case 'k':
                        kidding = 1;
                        break;
                case 'n':
                        nosync = 1;
                        break;
                case 'r':
                        doreboot = 1;
                        break;
                case 'v':
                        doverbose = 1;
                        break;
                case 'x':
                        dodebug = 1;
                        break;
                case 'z':
                        dosilent = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc < 1)
                usage();

        if (dodump && !dohalt && !doreboot)
                doreboot = 1;

        if (dofast && nosync) {
                warnx("Incompatible options -f and -n");
                usage();
        }
        if (dohalt && doreboot) {
                const char *which_flag = dopowerdown ? "p" : "h";

                warnx("Incompatible options -%s and -r", which_flag);
                usage();
        }

        getoffset(*argv++);

        if (argv[0]) {
                if (strcmp(argv[0], "-") || argv[1]) {
                        for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
                                arglen = strlen(*argv);
                                if ((len -= arglen) <= 2)
                                        break;
                                if (p != mbuf)
                                        *p++ = ' ';
                                (void)memmove(p, *argv, arglen);
                                p += arglen;
                        }
                        *p = '\n';
                        *++p = '\0';
                } else {
                        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);
        if (nofork == 0) {
                int forkpid;

                forkpid = fork();
                if (forkpid == -1) {
                        perror("shutdown: fork");
                        exit(1);
                }
                if (forkpid) {
                        (void)printf("shutdown: [pid %d]\n", forkpid);
                        exit(0);
                }
                (void)setsid();
        }
#endif
        openlog("shutdown", LOG_CONS, LOG_AUTH);
        loop();
        /* NOTREACHED */
#ifdef __GNUC__
        return 1;
#endif
}

static void
loop(void)
{
        const 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) != 0) {
                        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;

#define plural(n)       ((n) == 1 ? "" : "s")

static void
timewarn(time_t timeleft)
{
        static int first;
        static char hostname[MAXHOSTNAMELEN + 1];
        FILE *pf;
        char wcmd[MAXPATHLEN + 4];

        if (!first++) {
                (void)gethostname(hostname, sizeof(hostname));
                hostname[sizeof(hostname) - 1] = '\0';
        }

        /* undoc -n option to wall suppresses normal wall banner */
        (void)snprintf(wcmd, sizeof wcmd, "%s -n", _PATH_WALL);
        if ((pf = popen(wcmd, "w")) == NULL) {
                syslog(LOG_ERR, "%s: Can't find `%s' (%m)", getprogname(),
                    _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 %ld minute%s\n\n",
                    (long)timeleft / 60, plural((long)timeleft / 60));
        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, 1, mbuflen, pf);

        /*
         * play some games, just in case wall doesn't come back
         * probably unnecessary, 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);
        }
}

static void
/*ARGSUSED*/
timeout(int signo)
{
        longjmp(alarmbuf, 1);
}

static void
die_you_gravy_sucking_pig_dog(void)
{
        const char *what;

        if (doreboot) {
                what = "reboot";
        } else if (dohalt && dopowerdown) {
                what = "poweroff";
        } else if (dohalt) {
                what = "halt";
        } else {
                what = "shutdown";
        }

        syslog(LOG_NOTICE, "%s by %s: %s", what, whom, mbuf);
        (void)sleep(2);

        (void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
        if (kidding) {
                (void)printf("\rbut you'll have to do it yourself\r\n");
                finish(0);
        }
        if (dofast)
                doitfast();
        dorcshutdown(what);
        if (doreboot || dohalt) {
                const char *args[20];
                const char **arg, *path;
#ifndef DEBUG
                int serrno;
#endif

                arg = &args[0];
                if (doreboot) {
                        path = _PATH_REBOOT;
                        *arg++ = "reboot";
                } else {
                        path = _PATH_HALT;
                        *arg++ = "halt";
                }
                if (doverbose)
                        *arg++ = "-v";
                if (dodebug)
                        *arg++ = "-x";
                if (dosilent)
                        *arg++ = "-z";
                if (dodump)
                        *arg++ = "-d";
                if (nosync)
                        *arg++ = "-n";
                if (dopowerdown)
                        *arg++ = "-p";
                *arg++ = "-l";
                if (bootstr)
                        *arg++ = bootstr;
                *arg++ = NULL;
#ifndef DEBUG
                (void)unlink(_PATH_NOLOGIN);
                (void)execve(path, __UNCONST(args), NULL);
                serrno = errno;
                syslog(LOG_ERR, "Can't exec `%s' (%m)", path);
                errno = serrno;
                warn("Can't exec `%s'", path);
#else
                printf("%s", path);
                for (arg = &args[0]; *arg; arg++)
                        printf(" %s", *arg);
                printf("\n");
#endif
        } else {
#ifndef DEBUG
                (void)kill(1, SIGTERM);         /* to single user */
#else
                printf("kill 1\n");
#endif
        }
        finish(0);
}

#define ATOI2(s)        ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))

static void
getoffset(char *timearg)
{
        struct tm *lt;
        char *p;
        time_t now;
        int yearset;

        (void)time(&now);
        if (!strcasecmp(timearg, "now")) {              /* now */
                offset = 0;
                shuttime = now;
                return;
        }

        if (*timearg == '+') {                          /* +minutes */
                if (!isdigit((unsigned char)*++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((unsigned char)*p)) {
                        if (*p == ':' && strlen(p) == 3) {
                                p[0] = p[1];
                                p[1] = p[2];
                                p[2] = '\0';
                        }
                        else
                                badtime();
                }

        (void)unsetenv("TZ");                           /* OUR timezone */
        lt = localtime(&now);                           /* current time val */

        lt->tm_sec = 0;

        yearset = 0;
        switch (strlen(timearg)) {
        case 12:
                lt->tm_year = ATOI2(timearg) * 100 - TM_YEAR_BASE;
                yearset = 1;
                /* FALLTHROUGH */
        case 10:
                if (yearset) {
                        lt->tm_year += ATOI2(timearg);
                } else {
                        yearset = ATOI2(timearg);
                        if (yearset < 20)
                                lt->tm_year = yearset + 2100 - TM_YEAR_BASE;
                        else
                                lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
                }
                /* FALLTHROUGH */
        case 8:
                lt->tm_mon = ATOI2(timearg);
                if (lt->tm_mon < 1 || lt->tm_mon > 12)
                        badtime();
                --lt->tm_mon;
                /* 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();
                /* FALLTHROUGH */
        case 2:
                lt->tm_min = ATOI2(timearg);
                /* ignore possibility of a leap second */
                if (lt->tm_min < 0 || lt->tm_min > 59)
                        badtime();
                break;
        default:
                badtime();
        }

        if ((shuttime = mktime(lt)) == -1)
                badtime();
        if ((offset = shuttime - now) < 0)
                errx(1, "time is already past");
}

static void
dorcshutdown(const char *arg)
{
        static char cmd[sizeof(_PATH_RCSHUTDOWN) + 64];

        if (arg) {
                snprintf(cmd, sizeof(cmd), "set -- %s && . " _PATH_RCSHUTDOWN,
                    arg);
                cmd[sizeof(cmd)-1] = 0;
                arg = cmd;
        } else {
                arg = ". " _PATH_RCSHUTDOWN;
        }

        (void)printf("\r\nAbout to run shutdown hooks...\r\n");
#ifndef DEBUG
        (void)setuid(0);
        (void)system(arg);
#endif
        (void)sleep(5);         /* Give operator a chance to abort this. */
        (void)printf("\r\nDone running shutdown hooks.\r\n");
}

#define FSMSG   "fastboot file for fsck\n"
static void
doitfast(void)
{
        int fastfd;

        if ((fastfd = open(_PATH_FASTBOOT, O_WRONLY|O_CREAT|O_TRUNC,
            0664)) >= 0) {
                (void)write(fastfd, FSMSG, sizeof(FSMSG) - 1);
                (void)close(fastfd);
        }
}

#define NOMSG   "\n\nNO LOGINS: System going down at "
static void
nolog(void)
{
        int logfd;
        char *ct;

        if (kidding)
                return;

        (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);
        }
}

static void
/*ARGSUSED*/
finish(int signo)
{

        if (!kidding)
                (void)unlink(_PATH_NOLOGIN);
        exit(0);
}

static void
badtime(void)
{

        warnx("illegal time format");
        usage();
}

static void
usage(void)
{

        (void)fprintf(stderr,
            "Usage: %s [-Ddfhknprvxz] [-b bootstr] time [message ... | -]\n",
            getprogname());
        exit(1);
}