dist/ipf/lib/ntomask.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2002-2005 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  * Id: ntomask.c,v 1.6.2.1 2006/06/16 17:21:07 darrenr Exp
   9  */
  10
  11 #include "ipf.h"
  12
  13 int ntomask(v, nbits, ap)
  14 int v, nbits;
  15 u_32_t *ap;
  16 {
  17         u_32_t mask;
  18
  19         if (nbits < 0)
  20                 return -1;
  21
  22         switch (v)
  23         {
  24         case 4 :
  25                 if (nbits > 32 || use_inet6 != 0)
  26                         return -1;
  27                 if (nbits == 0) {
  28                         mask = 0;
  29                 } else {
  30                         mask = 0xffffffff;
  31                         mask <<= (32 - nbits);
  32                 }
  33                 *ap = htonl(mask);
  34                 break;
  35
  36         case 6 :
  37                 if ((nbits > 128) || (use_inet6 == 0))
  38                         return -1;
  39                 fill6bits(nbits, ap);
  40                 break;
  41
  42         default :
  43                 return -1;
  44         }
  45         return 0;
  46 }