/*      $OpenBSD: rdate.c,v 1.38 2026/03/27 14:33:58 deraadt Exp $      */
/*      $NetBSD: rdate.c,v 1.4 1996/03/16 12:37:45 pk Exp $     */

/*
 * Copyright (c) 1994 Christos Zoulas
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * rdate.c: Set the date from the specified host
 *
 *      Time is returned as the number of seconds since
 *      midnight January 1st 1900.
 */

#include <sys/socket.h>
#include <sys/time.h>
#include <sys/wait.h>

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <err.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

/* there are systems without libutil; for portability */
#ifndef NO_UTIL
#include <util.h>
#else
#define logwtmp(a,b,c)
#endif

void ntp_client(const char *, int, struct timeval *, struct timeval *, int);

extern char    *__progname;
__dead void     usage(void);

struct {
        char message[2048];
        struct timeval new;
        struct timeval adjust;
} pdata;

__dead void
usage(void)
{
        (void) fprintf(stderr, "usage: %s [-46acnpsv] host\n", __progname);
        exit(1);
}

int
main(int argc, char **argv)
{
        int             pr = 0, silent = 0, verbose = 0;
        int             slidetime = 0, corrleaps = 0;
        char           *hname;
        int             c, p[2], pid;
        int             family = PF_UNSPEC;

        while ((c = getopt(argc, argv, "46psanocv")) != -1) {
                switch (c) {
                case '4':
                        family = PF_INET;
                        break;

                case '6':
                        family = PF_INET6;
                        break;

                case 'p':
                        pr = 1;
                        break;

                case 's':
                        silent = 1;
                        break;

                case 'a':
                        slidetime = 1;
                        break;

                case 'n':
                        /* noop */
                        break;

                case 'c':
                        corrleaps = 1;
                        break;

                case 'v':
                        verbose = 1;
                        break;

                default:
                        usage();
                }
        }
        if (argc - 1 != optind)
                usage();
        hname = argv[optind];

        /*
         * Privilege separation increases safety, with a slight reduction
         * in precision because the time values have to return over a pipe.
         */
        if (pipe(p) == -1)
                err(1, "pipe");
        switch ((pid = fork())) {
        case -1:
                err(1, "fork");
                break;
        case 0:
                if (pledge("stdio inet dns", NULL) == -1)
                        err(1, "pledge");

                close(p[0]);    /* read side of pipe */
                dup2(p[1], STDIN_FILENO);
                if (p[1] != STDIN_FILENO)
                        close(p[1]);
                dup2(STDIN_FILENO, STDOUT_FILENO);
                dup2(STDOUT_FILENO, STDERR_FILENO);
                setvbuf(stdout, NULL, _IOFBF, 0);
                setvbuf(stderr, NULL, _IOFBF, 0);

                ntp_client(hname, family, &pdata.new,
                    &pdata.adjust, corrleaps);

                if (write(STDOUT_FILENO, &pdata, sizeof pdata) != sizeof pdata)
                        exit(1);
                exit(0);
        }

        if (pledge("stdio rpath wpath settime", NULL) == -1)
                err(1, "pledge");

        close(p[1]);    /* write side of pipe */
        if (read(p[0], &pdata, sizeof pdata) < 1)
                err(1, "child did not collect time");
        if (waitpid(pid, NULL, 0) == -1)
                err(1, "waitpid");

        /*
         * A viable timestamp from the child contains no message.
         */
        if (pdata.message[0]) {
                pdata.message[sizeof(pdata.message)- 1] = '\0';
                write(STDERR_FILENO, pdata.message, strlen(pdata.message));
                exit(1);
        }

        if (!pr) {
                if (!slidetime) {
                        logwtmp("|", "date", "");
                        if (settimeofday(&pdata.new, NULL) == -1)
                                err(1, "Could not set time of day");
                        logwtmp("{", "date", "");
                } else {
                        if (adjtime(&pdata.adjust, NULL) == -1)
                                err(1, "Could not adjust time of day");
                }
        }

        if (pledge("stdio rpath", NULL) == -1)
                err(1, "pledge");

        if (!silent) {
                struct tm      *ltm;
                char            buf[80];
                time_t          tim = pdata.new.tv_sec;
                double          adjsec;

                ltm = localtime(&tim);
                (void) strftime(buf, sizeof buf, "%a %b %e %H:%M:%S %Z %Y\n", ltm);
                (void) fputs(buf, stdout);

                adjsec  = pdata.adjust.tv_sec + pdata.adjust.tv_usec / 1.0e6;

                if (slidetime || verbose) {
                        (void) fprintf(stdout,
                           "%s: adjust local clock by %.6f seconds\n",
                           __progname, adjsec);
                }
        }

        return 0;
}