src/kits/network/netresolv/inet/inet_netof.c

   1 /*      $NetBSD: inet_netof.c,v 1.1 2004/05/20 23:13:02 christos Exp $  */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 #if 0
  39 static char sccsid[] = "@(#)inet_netof.c        8.1 (Berkeley) 6/4/93";
  40 #else
  41 __RCSID("$NetBSD: inet_netof.c,v 1.1 2004/05/20 23:13:02 christos Exp $");
  42 #endif
  43 #endif /* LIBC_SCCS and not lint */
  44
  45 #include "port_before.h"
  46
  47 #include <sys/param.h>
  48 #include <netinet/in.h>
  49 #include <arpa/inet.h>
  50
  51 #include "port_after.h"
  52
  53 /*
  54  * Return the network number from an internet
  55  * address; handles class a/b/c network #'s.
  56  */
  57 in_addr_t
  58 inet_netof(struct in_addr in)
  59 {
  60         in_addr_t i = ntohl(in.s_addr);
  61
  62         if (IN_CLASSA(i))
  63                 return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
  64         else if (IN_CLASSB(i))
  65                 return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
  66         else
  67                 return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
  68 }
  69
  70 #undef inet_netof
  71 #pragma weak inet_netof = __inet_netof