root/usr.bin/talk/get_addrs.c
/*      $OpenBSD: get_addrs.c,v 1.10 2016/02/01 07:29:25 mestre Exp $   */
/*      $NetBSD: get_addrs.c,v 1.3 1994/12/09 02:14:14 jtc Exp $        */

/*
 * Copyright (c) 1983, 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 <err.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>

#include "talk.h"
#include "talk_ctl.h"

void
get_addrs(char *my_machine_name, char *his_machine_name)
{
        struct hostent *hp;
        struct servent *sp;

        msg.pid = htonl(getpid());
        /* look up the address of the local host */
        hp = gethostbyname(my_machine_name);
        if (hp == NULL)
                errx(1, "%s: %s", my_machine_name, hstrerror(h_errno));
        bcopy(hp->h_addr, &my_machine_addr, hp->h_length);
        /*
         * If the callee is on-machine, just copy the
         * network address, otherwise do a lookup...
         */
        if (strcmp(his_machine_name, my_machine_name)) {
                hp = gethostbyname(his_machine_name);
                if (hp == NULL)
                        errx(1, "%s: %s", his_machine_name, hstrerror(h_errno));
                bcopy(hp->h_addr, &his_machine_addr, hp->h_length);
        } else
                his_machine_addr = my_machine_addr;
        /* find the server's port */
        sp = getservbyname("ntalk", "udp");
        if (sp == NULL)
                errx(1, "ntalk/udp: service is not registered.");
        daemon_port = sp->s_port;
}