xref: /openbsd/usr.bin/talk/get_addrs.c (revision 8d688443)
1 /*	$OpenBSD: get_addrs.c,v 1.10 2016/02/01 07:29:25 mestre Exp $	*/
2 /*	$NetBSD: get_addrs.c,v 1.3 1994/12/09 02:14:14 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1983, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <err.h>
34 #include <netdb.h>
35 #include <string.h>
36 #include <unistd.h>
37 
38 #include "talk.h"
39 #include "talk_ctl.h"
40 
41 void
get_addrs(char * my_machine_name,char * his_machine_name)42 get_addrs(char *my_machine_name, char *his_machine_name)
43 {
44 	struct hostent *hp;
45 	struct servent *sp;
46 
47 	msg.pid = htonl(getpid());
48 	/* look up the address of the local host */
49 	hp = gethostbyname(my_machine_name);
50 	if (hp == NULL)
51 		errx(1, "%s: %s", my_machine_name, hstrerror(h_errno));
52 	bcopy(hp->h_addr, &my_machine_addr, hp->h_length);
53 	/*
54 	 * If the callee is on-machine, just copy the
55 	 * network address, otherwise do a lookup...
56 	 */
57 	if (strcmp(his_machine_name, my_machine_name)) {
58 		hp = gethostbyname(his_machine_name);
59 		if (hp == NULL)
60 			errx(1, "%s: %s", his_machine_name, hstrerror(h_errno));
61 		bcopy(hp->h_addr, &his_machine_addr, hp->h_length);
62 	} else
63 		his_machine_addr = my_machine_addr;
64 	/* find the server's port */
65 	sp = getservbyname("ntalk", "udp");
66 	if (sp == NULL)
67 		errx(1, "ntalk/udp: service is not registered.");
68 	daemon_port = sp->s_port;
69 }
70