/* 

 * netof - return the net address part of an ip address in a sockaddr_storage structure

 *         (zero out host part)

 */

#include <config.h>

#include <stdio.h>

#include <syslog.h>

#include "ntp_fp.h"

#include "ntp_net.h"

#include "ntp_stdlib.h"

#include "ntp.h"

sockaddr_u *

netof(

  sockaddr_u *hostaddr

  )

{

  static sockaddr_u netofbuf[8];

  static int    next_netofbuf;

  u_int32     netnum;

  sockaddr_u *    netaddr;

  netaddr = &netofbuf[next_netofbuf];

  next_netofbuf = (next_netofbuf + 1) % COUNTOF(netofbuf);

  memcpy(netaddr, hostaddr, sizeof(*netaddr));

  if (IS_IPV4(netaddr)) {

    netnum = SRCADR(netaddr);

    /*

     * We live in a modern CIDR world where the basement nets, which

     * used to be class A, are now probably associated with each

     * host address. So, for class-A nets, all bits are significant.

     */

    if (IN_CLASSC(netnum))

      netnum &= IN_CLASSC_NET;

    else if (IN_CLASSB(netnum))

      netnum &= IN_CLASSB_NET;

    SET_ADDR4(netaddr, netnum);

  } else if (IS_IPV6(netaddr))

    /* assume the typical /64 subnet size */

    zero_mem(&NSRCADR6(netaddr)[8], 8);

#ifdef DEBUG

  else {

    msyslog(LOG_ERR, "netof unknown AF %d", AF(netaddr));

    exit(1);

  }

#endif

  return netaddr;

}