/* $NetBSD: netdate.c,v 1.30 2011/01/29 02:16:52 christos Exp $ */

/*-
 * Copyright (c) 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
#if 0
static char sccsid[] = "@(#)netdate.c   8.2 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: netdate.c,v 1.30 2011/01/29 02:16:52 christos Exp $");
#endif
#endif /* not lint */

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

#include <netinet/in.h>
#include <netdb.h>
#define TSPTYPES
#include <protocols/timed.h>

#include <err.h>
#include <errno.h>
#include <poll.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "extern.h"

#define WAITACK         2000    /* milliseconds */
#define WAITDATEACK     5000    /* milliseconds */

static const char *
tsp_type_to_string(const struct tsp *msg)
{
        unsigned i;

        i = msg->tsp_type;
        return i < TSPTYPENUMBER ? tsptype[i] : "unknown";
}

/*
 * Set the date in the machines controlled by timedaemons by communicating the
 * new date to the local timedaemon.  If the timedaemon is in the master state,
 * it performs the correction on all slaves.  If it is in the slave state, it
 * notifies the master that a correction is needed.
 * Returns 0 on success.  Returns > 0 on failure.
 */
int
netsettime(time_t tval)
{
        struct sockaddr_in dest;
        struct tsp msg;
        char hostname[MAXHOSTNAMELEN];
        struct servent *sp;
        struct pollfd ready;
        int found, s, timed_ack, waittime;

        if ((sp = getservbyname("timed", "udp")) == NULL) {
                warnx("udp/timed: unknown service");
                return 2;
        }

        (void)memset(&dest, 0, sizeof(dest));
#ifdef BSD4_4
        dest.sin_len = sizeof(dest);
#endif
        dest.sin_family = AF_INET;
        dest.sin_port = sp->s_port;
        dest.sin_addr.s_addr = htonl(INADDR_ANY);
        s = socket(AF_INET, SOCK_DGRAM, 0);
        if (s == -1) {
                if (errno != EAFNOSUPPORT)
                        warn("timed");
                return 2;
        }

#ifdef IP_PORTRANGE
        {
                static const int on = IP_PORTRANGE_LOW;

                if (setsockopt(s, IPPROTO_IP, IP_PORTRANGE, &on,
                    sizeof(on)) == -1) {
                        warn("setsockopt");
                        goto bad;
                }
        }
#endif

        msg.tsp_type = TSP_SETDATE;
        msg.tsp_vers = TSPVERSION;
        if (gethostname(hostname, sizeof(hostname)) == -1) {
                warn("gethostname");
                goto bad;
        }
        (void)strlcpy(msg.tsp_name, hostname, sizeof(msg.tsp_name));
        msg.tsp_seq = htons((in_port_t)0);
        msg.tsp_time.tv_sec = htonl((in_addr_t)tval); /* XXX: y2038 */
        msg.tsp_time.tv_usec = htonl((in_addr_t)0);
        if (connect(s, (const void *)&dest, sizeof(dest)) == -1) {
                warn("connect");
                goto bad;
        }
        if (send(s, &msg, sizeof(msg), 0) == -1) {
                if (errno != ECONNREFUSED)
                        warn("send");
                goto bad;
        }

        timed_ack = -1;
        waittime = WAITACK;
        ready.fd = s;
        ready.events = POLLIN;
loop:
        found = poll(&ready, 1, waittime);

        {
                socklen_t len;
                int error;

                len = sizeof(error);
                if (getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &len) == -1) {
                        warn("getsockopt");
                        goto bad;
                }
                if (error) {
                        if (error != ECONNREFUSED) {
                                errno = error;
                                warn("send (delayed error)");
                        }
                        goto bad;
                }
        }

        if (found > 0 && ready.revents & POLLIN) {
                ssize_t ret;

                if ((ret = recv(s, &msg, sizeof(msg), 0)) == -1) {
                        if (errno != ECONNREFUSED)
                                warn("recv");
                        goto bad;
                } else if ((size_t)ret < sizeof(msg)) {
                        warnx("recv: incomplete packet");
                        goto bad;
                }

                msg.tsp_seq = ntohs(msg.tsp_seq);
                msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
                msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
                switch (msg.tsp_type) {
                case TSP_ACK:
                        timed_ack = TSP_ACK;
                        waittime = WAITDATEACK;
                        goto loop;
                case TSP_DATEACK:
                        (void)close(s);
                        return 0;
                default:
                        warnx("wrong ack received from timed: %s", 
                            tsp_type_to_string(&msg));
                        timed_ack = -1;
                        break;
                }
        }
        if (timed_ack == -1)
                warnx("can't reach time daemon, time set locally");

bad:
        (void)close(s);
        return 2;
}