xref: /netbsd-src/external/bsd/ipf/dist/lib/hostname.c (revision 83ff0d3d9dcc94f07b6d52fe277a99aef579a9f0)
1 /*	$NetBSD: hostname.c,v 1.3 2012/10/22 01:21:57 christos Exp $	*/
2 
3 /*
4  * Copyright (C) 2012 by Darren Reed.
5  *
6  * See the IPFILTER.LICENCE file for details on licencing.
7  *
8  * Id: hostname.c,v 1.1.1.2 2012/07/22 13:44:38 darrenr Exp $
9  */
10 
11 #include "ipf.h"
12 
13 char *
hostname(int family,const void * ip)14 hostname(int family, const void *ip)
15 {
16 	static char hostbuf[MAXHOSTNAMELEN+1];
17 	struct hostent *hp;
18 	struct in_addr ipa;
19 	struct netent *np;
20 
21 	memset(&ipa, 0, sizeof(ipa));	/* XXX gcc */
22 
23 	if (family == AF_INET) {
24 		ipa.s_addr = *(const u_32_t *)ip;
25 		if (ipa.s_addr == htonl(0xfedcba98))
26 			return "test.host.dots";
27 	}
28 
29 	if ((opts & OPT_NORESOLVE) == 0) {
30 		if (family == AF_INET) {
31 			hp = gethostbyaddr(ip, 4, AF_INET);
32 			if (hp != NULL && hp->h_name != NULL &&
33 			    *hp->h_name != '\0') {
34 				strncpy(hostbuf, hp->h_name, sizeof(hostbuf));
35 				hostbuf[sizeof(hostbuf) - 1] = '\0';
36 				return hostbuf;
37 			}
38 
39 			np = getnetbyaddr(ipa.s_addr, AF_INET);
40 			if (np != NULL && np->n_name != NULL &&
41 			    *np->n_name != '\0') {
42 				strncpy(hostbuf, np->n_name, sizeof(hostbuf));
43 				hostbuf[sizeof(hostbuf) - 1] = '\0';
44 				return hostbuf;
45 			}
46 		}
47 	}
48 
49 	if (family == AF_INET) {
50 		return inet_ntoa(ipa);
51 	}
52 #ifdef  USE_INET6
53 	(void) inet_ntop(AF_INET6, ip, hostbuf, sizeof(hostbuf) - 1);
54 	hostbuf[MAXHOSTNAMELEN] = '\0';
55 	return hostbuf;
56 #else
57 	return "IPv6";
58 #endif
59 }
60