/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice, 
 *   this list of conditions and the following disclaimer.
 * - 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.
 * - Neither the name of Sun Microsystems, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
 */

/*
 * Copyright (c) 1988 by Sun Microsystems, Inc.

 */

/*
 * rtime - get time from remote machine
 *
 * gets time, obtaining value from host
 * on the udp/time socket.  Since timeserver returns
 * with time of day in seconds since Jan 1, 1900,  must
 * subtract seconds before Jan 1, 1970 to get
 * what unix uses.
 */
#include "namespace.h"
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <stdio.h>
#include <netdb.h>
#include "un-namespace.h"

extern int _rpc_dtablesize( void );

#define NYEARS  (unsigned long)(1970 - 1900)
#define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))

static void do_close( int );

int
rtime(struct sockaddr_in *addrp, struct timeval *timep,
    struct timeval *timeout)
{
        int s;
        fd_set readfds;
        int res;
        unsigned long thetime;
        struct sockaddr_in from;
        socklen_t fromlen;
        int type;
        struct servent *serv;

        if (timeout == NULL) {
                type = SOCK_STREAM;
        } else {
                type = SOCK_DGRAM;
        }
        s = _socket(AF_INET, type, 0);
        if (s < 0) {
                return(-1);
        }
        addrp->sin_family = AF_INET;

        /* TCP and UDP port are the same in this case */
        if ((serv = getservbyname("time", "tcp")) == NULL) {
                return(-1);
        }

        addrp->sin_port = serv->s_port;

        if (type == SOCK_DGRAM) {
                res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
                             (struct sockaddr *)addrp, sizeof(*addrp));
                if (res < 0) {
                        do_close(s);
                        return(-1);
                }
                do {
                        FD_ZERO(&readfds);
                        FD_SET(s, &readfds);
                        res = _select(_rpc_dtablesize(), &readfds,
                                     (fd_set *)NULL, (fd_set *)NULL, timeout);
                } while (res < 0 && errno == EINTR);
                if (res <= 0) {
                        if (res == 0) {
                                errno = ETIMEDOUT;
                        }
                        do_close(s);
                        return(-1);
                }
                fromlen = sizeof(from);
                res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
                               (struct sockaddr *)&from, &fromlen);
                do_close(s);
                if (res < 0) {
                        return(-1);
                }
        } else {
                if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
                        do_close(s);
                        return(-1);
                }
                res = _read(s, (char *)&thetime, sizeof(thetime));
                do_close(s);
                if (res < 0) {
                        return(-1);
                }
        }
        if (res != sizeof(thetime)) {
                errno = EIO;
                return(-1);
        }
        thetime = ntohl(thetime);
        timep->tv_sec = thetime - TOFFSET;
        timep->tv_usec = 0;
        return(0);
}

static void
do_close(int s)
{
        int save;

        save = errno;
        (void)_close(s);
        errno = save;
}