usr/src/sbin/reboot/reboot.c

/*
 * Copyright (c) 1980, 1986 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980, 1986 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)reboot.c    5.13 (Berkeley) %G%";
#endif /* not lint */

#include <sys/reboot.h>
#include <signal.h>
#include <pwd.h>
#include <errno.h>
#include <syslog.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void err __P((const char *fmt, ...));
void usage __P((void));

int dohalt;

int
main(argc, argv)
        int argc;
        char *argv[];
{
        register int i;
        struct passwd *pw;
        int ch, howto, lflag, nflag, qflag, sverrno;
        char *p, *user;

        if (!strcmp((p = rindex(*argv, '/')) ? p + 1 : *argv, "halt")) {
                dohalt = 1;
                howto = RB_HALT;
        } else
                howto = 0;
        lflag = nflag = qflag = 0;
        while ((ch = getopt(argc, argv, "lnq")) != EOF)
                switch(ch) {
                case 'l':               /* Undocumented; used by shutdown. */
                        lflag = 1;
                        break;
                case 'n':
                        nflag = 1;
                        howto |= RB_NOSYNC;
                        break;
                case 'q':
                        qflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (geteuid())
                err("%s", strerror(EPERM));

        if (qflag) {
                reboot(howto);
                err("%s", strerror(errno));
        }

        /* Log the reboot. */
        if (!lflag)  {
                if ((user = getlogin()) == NULL)
                        user = (pw = getpwuid(getuid())) ?
                            pw->pw_name : "???";
                if (dohalt) {
                        openlog("halt", 0, LOG_AUTH | LOG_CONS);
                        syslog(LOG_CRIT, "halted by %s", user);
                } else {
                        openlog("reboot", 0, LOG_AUTH | LOG_CONS);
                        syslog(LOG_CRIT, "rebooted by %s", user);
                }
        }
        logwtmp("~", "shutdown", "");

        /*
         * 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();

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

        /* Ignore the SIGHUP we get when our parent shell dies. */
        (void)signal(SIGHUP, SIG_IGN);

        /* Send a SIGTERM first, a chance to save the buffers. */
        if (kill(-1, SIGTERM) == -1)
                err("SIGTERM processes: %s", strerror(errno));

        /*
         * 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 give everybody a chance.
         */
        sleep(2);
        if (!nflag)
                sync();
        sleep(3);

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

        reboot(howto);
        /* FALLTHROUGH */

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

void
usage()
{
        (void)fprintf(stderr, "usage: %s [-nq]\n", dohalt ? "halt" : "reboot");
        exit(1);
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)fprintf(stderr, "%s: ", dohalt ? "halt" : "reboot");
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        exit(1);
        /* NOTREACHED */
}