dist/ipf/lib/fill6bits.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2000-2002 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  * Id: fill6bits.c,v 1.5.4.1 2006/06/16 17:20:58 darrenr Exp
   9  */
  10
  11 #include "ipf.h"
  12
  13
  14 void fill6bits(bits, msk)
  15 int bits;
  16 u_int *msk;
  17 {
  18         if (bits == 0) {
  19                 msk[0] = 0;
  20                 msk[1] = 0;
  21                 msk[2] = 0;
  22                 msk[3] = 0;
  23                 return;
  24         }
  25
  26         msk[0] = 0xffffffff;
  27         msk[1] = 0xffffffff;
  28         msk[2] = 0xffffffff;
  29         msk[3] = 0xffffffff;
  30
  31         if (bits == 128)
  32                 return;
  33         if (bits > 96) {
  34                 msk[3] = htonl(msk[3] << (128 - bits));
  35         } else if (bits > 64) {
  36                 msk[3] = 0;
  37                 msk[2] = htonl(msk[2] << (96 - bits));
  38         } else if (bits > 32) {
  39                 msk[3] = 0;
  40                 msk[2] = 0;
  41                 msk[1] = htonl(msk[1] << (64 - bits));
  42         } else {
  43                 msk[3] = 0;
  44                 msk[2] = 0;
  45                 msk[1] = 0;
  46                 msk[0] = htonl(msk[0] << (32 - bits));
  47         }
  48 }