contrib/ipfilter/lib/hostname.c

   1 /*      $FreeBSD$       */
   2
   3
   4 #include "ipf.h"
   5
   6 char *hostname(v, ip)
   7 int v;
   8 void *ip;
   9 {
  10         static char hostbuf[MAXHOSTNAMELEN+1];
  11         struct hostent *hp;
  12         struct in_addr ipa;
  13         struct netent *np;
  14
  15         if (v == 4) {
  16                 ipa.s_addr = *(u_32_t *)ip;
  17                 if (ipa.s_addr == htonl(0xfedcba98))
  18                         return "test.host.dots";
  19         }
  20
  21         if ((opts & OPT_NORESOLVE) == 0) {
  22                 if (v == 4) {
  23                         hp = gethostbyaddr(ip, 4, AF_INET);
  24                         if (hp != NULL && hp->h_name != NULL &&
  25                             *hp->h_name != '\0') {
  26                                 strncpy(hostbuf, hp->h_name, sizeof(hostbuf));
  27                                 hostbuf[sizeof(hostbuf) - 1] = '\0';
  28                                 return hostbuf;
  29                         }
  30
  31                         np = getnetbyaddr(ipa.s_addr, AF_INET);
  32                         if (np != NULL && np->n_name != NULL &&
  33                             *np->n_name != '\0') {
  34                                 strncpy(hostbuf, np->n_name, sizeof(hostbuf));
  35                                 hostbuf[sizeof(hostbuf) - 1] = '\0';
  36                                 return hostbuf;
  37                         }
  38                 }
  39         }
  40
  41         if (v == 4) {
  42                 return inet_ntoa(ipa);
  43         }
  44 #ifdef  USE_INET6
  45         (void) inet_ntop(AF_INET6, ip, hostbuf, sizeof(hostbuf) - 1);
  46         hostbuf[MAXHOSTNAMELEN] = '\0';
  47         return hostbuf;
  48 #else
  49         return "IPv6";
  50 #endif
  51 }