lib/common/hostname.c

/*
 * Copyright (C) 2003 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#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;

    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
}