lib/hostname.c

/*
 * Copyright (C) 2010 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * $Id$
 */

#include "ipf.h"

char *hostname(v, ip)
int v;
void *ip;
{
	static char hostbuf[MAXHOSTNAMELEN+1];
	struct hostent *hp;
	struct in_addr ipa;
	struct netent *np;

	memset(&ipa, 0, sizeof(ipa));	/* XXX gcc */

	if (v == 4) {
		ipa.s_addr = *(u_32_t *)ip;
		if (ipa.s_addr == htonl(0xfedcba98))
			return "test.host.dots";
	}

	if ((opts & OPT_NORESOLVE) == 0) {
		if (v == 4) {
			hp = gethostbyaddr(ip, 4, AF_INET);
			if (hp != NULL && hp->h_name != NULL &&
			    *hp->h_name != '\0') {
				strncpy(hostbuf, hp->h_name, sizeof(hostbuf));
				hostbuf[sizeof(hostbuf) - 1] = '\0';
				return hostbuf;
			}

			np = getnetbyaddr(ipa.s_addr, AF_INET);
			if (np != NULL && np->n_name != NULL &&
			    *np->n_name != '\0') {
				strncpy(hostbuf, np->n_name, sizeof(hostbuf));
				hostbuf[sizeof(hostbuf) - 1] = '\0';
				return hostbuf;
			}
		}
	}

	if (v == 4) {
		return inet_ntoa(ipa);
	}
#ifdef  USE_INET6
	(void) inet_ntop(AF_INET6, ip, hostbuf, sizeof(hostbuf) - 1);
	hostbuf[MAXHOSTNAMELEN] = '\0';
	return hostbuf;
#else
	return "IPv6";
#endif
}