contrib/ipfilter/lib/hostname.c

   1 /*      $FreeBSD$       */
   2
   3 /*
   4  * Copyright (C) 2002-2003 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  * $Id: hostname.c,v 1.6.2.2 2007/01/16 02:25:22 darrenr Exp $
   9  */
  10
  11 #include "ipf.h"
  12
  13 char *hostname(v, ip)
  14 int v;
  15 void *ip;
  16 {
  17         static char hostbuf[MAXHOSTNAMELEN+1];
  18         struct hostent *hp;
  19         struct in_addr ipa;
  20         struct netent *np;
  21
  22         memset(&ipa, 0, sizeof(ipa));   /* XXX gcc */
  23
  24         if (v == 4) {
  25                 ipa.s_addr = *(u_32_t *)ip;
  26                 if (ipa.s_addr == htonl(0xfedcba98))
  27                         return "test.host.dots";
  28         }
  29
  30         if ((opts & OPT_NORESOLVE) == 0) {
  31                 if (v == 4) {
  32                         hp = gethostbyaddr(ip, 4, AF_INET);
  33                         if (hp != NULL && hp->h_name != NULL &&
  34                             *hp->h_name != '\0') {
  35                                 strncpy(hostbuf, hp->h_name, sizeof(hostbuf));
  36                                 hostbuf[sizeof(hostbuf) - 1] = '\0';
  37                                 return hostbuf;
  38                         }
  39
  40                         np = getnetbyaddr(ipa.s_addr, AF_INET);
  41                         if (np != NULL && np->n_name != NULL &&
  42                             *np->n_name != '\0') {
  43                                 strncpy(hostbuf, np->n_name, sizeof(hostbuf));
  44                                 hostbuf[sizeof(hostbuf) - 1] = '\0';
  45                                 return hostbuf;
  46                         }
  47                 }
  48         }
  49
  50         if (v == 4) {
  51                 return inet_ntoa(ipa);
  52         }
  53 #ifdef  USE_INET6
  54         (void) inet_ntop(AF_INET6, ip, hostbuf, sizeof(hostbuf) - 1);
  55         hostbuf[MAXHOSTNAMELEN] = '\0';
  56         return hostbuf;
  57 #else
  58         return "IPv6";
  59 #endif
  60 }