usr/src/cmd/ipf/lib/common/hostname.c

   1 /*
   2  * Copyright (C) 2003 by Darren Reed.
   3  *
   4  * See the IPFILTER.LICENCE file for details on licencing.
   5  *
   6  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   7  * Use is subject to license terms.
   8  */
   9
  10 #pragma ident   "%Z%%M% %I%     %E% SMI"
  11
  12 #include "ipf.h"
  13
  14 char *hostname(v, ip)
  15 int v;
  16 void *ip;
  17 {
  18         static char hostbuf[MAXHOSTNAMELEN+1];
  19         struct hostent *hp;
  20         struct in_addr ipa;
  21         struct netent *np;
  22
  23         if (v == 4) {
  24                 ipa.s_addr = *(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 (v == 4) {
  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 (v == 4) {
  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 }