1  /*
       2   * Copyright (c) 1983, 1993
       3   *	The Regents of the University of California.  All rights reserved.
       4   *
       5   * Redistribution and use in source and binary forms, with or without
       6   * modification, are permitted provided that the following conditions
       7   * are met:
       8   * 1. Redistributions of source code must retain the above copyright
       9   *    notice, this list of conditions and the following disclaimer.
      10   * 2. Redistributions in binary form must reproduce the above copyright
      11   *    notice, this list of conditions and the following disclaimer in the
      12   *    documentation and/or other materials provided with the distribution.
      13   * 4. Neither the name of the University nor the names of its contributors
      14   *    may be used to endorse or promote products derived from this software
      15   *    without specific prior written permission.
      16   *
      17   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      18   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      19   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      20   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      21   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      22   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      23   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      24   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      25   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      26   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      27   * SUCH DAMAGE.
      28   */
      29  
      30  #include <sys/param.h>
      31  #include <netinet/in.h>
      32  #include <arpa/inet.h>
      33  
      34  /*
      35   * Return the local network address portion of an
      36   * internet address; handles class a/b/c network
      37   * number formats.
      38   */
      39  in_addr_t
      40  inet_lnaof (struct in_addr in)
      41  {
      42  	uint32_t i = ntohl(in.s_addr);
      43  
      44  	if (IN_CLASSA(i))
      45  		return ((i)&IN_CLASSA_HOST);
      46  	else if (IN_CLASSB(i))
      47  		return ((i)&IN_CLASSB_HOST);
      48  	else
      49  		return ((i)&IN_CLASSC_HOST);
      50  }