usr/src/usr.bin/talk/get_addrs.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)get_addrs.c 5.5 (Berkeley) %G%";
#endif /* not lint */

#include "talk_ctl.h"
#include <netdb.h>

get_addrs(my_machine_name, his_machine_name)
        char *my_machine_name, *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) {
                fprintf(stderr, "talk: %s: ", my_machine_name);
                herror((char *)NULL);
                exit(-1);
        }
        bcopy(hp->h_addr, (char *)&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) {
                        fprintf(stderr, "talk: %s: ", his_machine_name);
                        herror((char *)NULL);
                        exit(-1);
                }
                bcopy(hp->h_addr, (char *) &his_machine_addr, hp->h_length);
        } else
                his_machine_addr = my_machine_addr;
        /* find the server's port */
        sp = getservbyname("ntalk", "udp");
        if (sp == 0) {
                fprintf(stderr, "talk: %s/%s: service is not registered.\n",
                     "ntalk", "udp");
                exit(-1);
        }
        daemon_port = sp->s_port;
}