/*      $NetBSD: reboot.c,v 1.41 2019/08/08 21:14:12 roy Exp $  */

/*
 * Copyright (c) 1980, 1986, 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) 1980, 1986, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)reboot.c    8.1 (Berkeley) 6/5/93";
#else
__RCSID("$NetBSD: reboot.c,v 1.41 2019/08/08 21:14:12 roy Exp $");
#endif
#endif /* not lint */

#include <sys/reboot.h>

#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <util.h>
#ifdef SUPPORT_UTMPX
#include <utmpx.h>
#endif

__dead static void usage(void);

static int dohalt;
static int dopoweroff;

int
main(int argc, char *argv[])
{
        const char *progname;
        int i;
        struct passwd *pw;
        int ch, howto, lflag, nflag, qflag, sverrno, len;
        const char *user;
        char *bootstr, **av;

        progname = getprogname();
        if (progname[0] == '-')
                progname++;
        if (strcmp(progname, "halt") == 0) {
                dohalt = 1;
                howto = RB_HALT;
        } else if (strcmp(progname, "poweroff") == 0) {
                dopoweroff = 1;
                howto = RB_HALT | RB_POWERDOWN;
        } else
                howto = 0;
        lflag = nflag = qflag = 0;
        while ((ch = getopt(argc, argv, "dlnpqvxz")) != -1)
                switch(ch) {
                case 'd':
                        howto |= RB_DUMP;
                        break;
                case 'l':
                        lflag = 1;
                        break;
                case 'n':
                        nflag = 1;
                        howto |= RB_NOSYNC;
                        break;
                case 'p':
                        if (dohalt == 0)
                                usage();
                        howto |= RB_POWERDOWN;
                        break;
                case 'q':
                        qflag = 1;
                        break;
                case 'v':
                        howto |= AB_VERBOSE;
                        break;
                case 'x':
                        howto |= AB_DEBUG;
                        break;
                case 'z':
                        howto |= AB_SILENT;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc) {
                for (av = argv, len = 0; *av; av++)
                        len += strlen(*av) + 1;
                bootstr = malloc(len + 1);
                *bootstr = '\0';                /* for first strcat */
                for (av = argv; *av; av++) {
                        strcat(bootstr, *av);
                        strcat(bootstr, " ");
                }
                bootstr[len - 1] = '\0';        /* to kill last space */
                howto |= RB_STRING;
        } else
                bootstr = NULL;

        if (geteuid())
                errx(1, "%s", strerror(EPERM));

        if (qflag) {
                reboot(howto, bootstr);
                err(1, "reboot");
        }

        /* Log the reboot. */
        if (!lflag)  {
                if ((user = getlogin()) == NULL)
                        user = (pw = getpwuid(getuid())) ?
                            pw->pw_name : "???";
                if (dohalt) {
                        openlog("halt", LOG_CONS, LOG_AUTH);
                        syslog(LOG_CRIT, "halted by %s", user);
                } else if (dopoweroff) {
                        openlog("poweroff", LOG_CONS, LOG_AUTH);
                        syslog(LOG_CRIT, "powered off by %s", user);
                } else {
                        openlog("reboot", LOG_CONS, LOG_AUTH);
                        if (bootstr)
                                syslog(LOG_CRIT, "rebooted by %s: %s", user,
                                    bootstr);
                        else
                                syslog(LOG_CRIT, "rebooted by %s", user);
                }
        }
#ifdef SUPPORT_UTMP
        logwtmp("~", "shutdown", "");
#endif
#ifdef SUPPORT_UTMPX
        logwtmpx("~", "shutdown", "", 0, INIT_PROCESS);
#endif

        /*
         * Do a sync early on, so disks start transfers while we're off
         * killing processes.  Don't worry about writes done before the
         * processes die, the reboot system call syncs the disks.
         */
        if (!nflag)
                sync();

        /* 
         * Ignore signals that we can get as a result of killing
         * parents, group leaders, etc.
         */
        (void)signal(SIGHUP,  SIG_IGN);
        (void)signal(SIGINT,  SIG_IGN);
        (void)signal(SIGQUIT, SIG_IGN);
        (void)signal(SIGTERM, SIG_IGN);
        (void)signal(SIGTSTP, SIG_IGN);

        /*
         * If we're running in a pipeline, we don't want to die
         * after killing whatever we're writing to.
         */
        (void)signal(SIGPIPE, SIG_IGN);

        /* Just stop init -- if we fail, we'll restart it. */
        if (kill(1, SIGTSTP) == -1)
                err(1, "SIGTSTP init");

        /* Send a SIGTERM first, a chance to save the buffers. */
        if (kill(-1, SIGTERM) == -1) {
                /*
                 * If ESRCH, everything's OK: we're the only non-system
                 * process!  That can happen e.g. via 'exec reboot' in
                 * single-user mode.
                 */
                if (errno != ESRCH) {
                        warn("SIGTERM all processes");
                        goto restart;
                }
        }

        /*
         * After the processes receive the signal, start the rest of the
         * buffers on their way.  Wait 5 seconds between the SIGTERM and
         * the SIGKILL to pretend to give everybody a chance.
         */
        sleep(2);
        if (!nflag)
                sync();
        sleep(3);

        for (i = 1;; ++i) {
                if (kill(-1, SIGKILL) == -1) {
                        if (errno == ESRCH)
                                break;
                        warn("SIGKILL all processes");
                        goto restart;
                }
                if (i > 5) {
                        warnx("WARNING: some process(es) wouldn't die");
                        break;
                }
                (void)sleep(2 * i);
        }

        reboot(howto, bootstr);
        warn("reboot()");
        /* FALLTHROUGH */

restart:
        sverrno = errno;
        errx(1, "%s%s", kill(1, SIGHUP) == -1 ? "(can't restart init): " : "",
            strerror(sverrno));
        /* NOTREACHED */
}

static void
usage(void)
{
        const char *pflag = dohalt ? "p" : "";

        (void)fprintf(stderr, "usage: %s [-dln%sqvxz] [-- <boot string>]\n",
            getprogname(), pflag);
        exit(1);
}