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

   1 /*
   2  * Copyright (C) 2002 by Darren Reed.
   3  *
   4  * See the IPFILTER.LICENCE file for details on licencing.
   5  *
   6  * Copyright 2005 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 int ntomask(v, nbits, ap)
  15 int v, nbits;
  16 u_32_t *ap;
  17 {
  18         u_32_t mask;
  19
  20         if (nbits < 0)
  21                 return -1;
  22
  23         switch (v)
  24         {
  25         case 4 :
  26                 if (nbits > 32 || use_inet6 != 0)
  27                         return -1;
  28                 if (nbits == 0) {
  29                         mask = 0;
  30                 } else {
  31                         mask = 0xffffffff;
  32                         mask <<= (32 - nbits);
  33                 }
  34                 *ap = htonl(mask);
  35                 break;
  36
  37         case 6 :
  38                 if (nbits > 128)
  39                         return -1;
  40                 fill6bits(nbits, ap);
  41                 break;
  42
  43         default :
  44                 return -1;
  45         }
  46         return 0;
  47 }