xref: /netbsd-src/usr.bin/talk/get_addrs.c (revision 5bbd2a12505d72a8177929a37b5cee489d0a1cfd)
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