lib/libc/inet/inet_makeaddr.c

   1 /*      $NetBSD: inet_makeaddr.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. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)inet_makeaddr.c     8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: inet_makeaddr.c,v 1.1 2004/05/20 23:13:02 christos Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include <sys/param.h>
  43 #include <netinet/in.h>
  44 #include <arpa/inet.h>
  45
  46 #ifdef __weak_alias
  47 __weak_alias(inet_makeaddr,_inet_makeaddr)
  48 #endif
  49
  50 /*
  51  * Formulate an Internet address from network + host.  Used in
  52  * building addresses stored in the ifnet structure.
  53  */
  54 struct in_addr
  55 inet_makeaddr(in_addr_t net, in_addr_t host)
  56 {
  57         in_addr_t addr;
  58         struct in_addr ret;
  59
  60         if (net < 128)
  61                 addr = (net << IN_CLASSA_NSHIFT) | (host & IN_CLASSA_HOST);
  62         else if (net < 65536)
  63                 addr = (net << IN_CLASSB_NSHIFT) | (host & IN_CLASSB_HOST);
  64         else if (net < 16777216L)
  65                 addr = (net << IN_CLASSC_NSHIFT) | (host & IN_CLASSC_HOST);
  66         else
  67                 addr = net | host;
  68         ret.s_addr = htonl(addr);
  69         return ret;
  70 }