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get_addrs.c revision 1.10 
      1 /*	$NetBSD: get_addrs.c,v 1.10 2011/09/06 18:32:03 joerg Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)get_addrs.c	8.1 (Berkeley) 6/6/93";
     36 #endif
     37 __RCSID("$NetBSD: get_addrs.c,v 1.10 2011/09/06 18:32:03 joerg Exp $");
     38 #endif /* not lint */
     39 
     40 #include "talk.h"
     41 #include <netdb.h>
     42 #include <stdio.h>
     43 #include <stdlib.h>
     44 #include <unistd.h>
     45 #include "talk_ctl.h"
     46 
     47 void
     48 get_addrs(const char *my_machine_name, const char *his_machine_name)
     49 {
     50 	struct hostent *hp;
     51 	struct servent *sp;
     52 
     53 	msg.pid = htonl(getpid());
     54 	/* look up the address of the local host */
     55 	hp = gethostbyname(my_machine_name);
     56 	if (hp == NULL) {
     57 		fprintf(stderr, "talk: %s: ", my_machine_name);
     58 		herror(NULL);
     59 		exit(1);
     60 	}
     61 	memmove((char *)&my_machine_addr, hp->h_addr, hp->h_length);
     62 	/*
     63 	 * If the callee is on-machine, just copy the
     64 	 * network address, otherwise do a lookup...
     65 	 */
     66 	if (strcmp(his_machine_name, my_machine_name)) {
     67 		hp = gethostbyname(his_machine_name);
     68 		if (hp == NULL) {
     69 			fprintf(stderr, "talk: %s: ", his_machine_name);
     70 			herror(NULL);
     71 			exit(1);
     72 		}
     73 		memmove((char *) &his_machine_addr, hp->h_addr, hp->h_length);
     74 	} else
     75 		his_machine_addr = my_machine_addr;
     76 	/* find the server's port */
     77 	sp = getservbyname("ntalk", "udp");
     78 	if (sp == 0) {
     79 		fprintf(stderr, "talk: %s/%s: service is not registered.\n",
     80 		     "ntalk", "udp");
     81 		exit(1);
     82 	}
     83 	daemon_port = sp->s_port;
     84 }
     85