/*
 * dhcpcd - DHCP client daemon
 * Copyright 2006-2008 Roy Marples <roy@marples.name>
 * All rights reserved

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <errno.h>
#include <stdlib.h>

#include "config.h"
#include "arp.h"
#include "ipv4ll.h"

#ifdef ENABLE_IPV4LL

#ifndef ENABLE_ARP
# error IPV4LL requires ARP
#endif

#define IPV4LL_LEASETIME 20

int ipv4ll_get_address (interface_t *iface, dhcp_t *dhcp)
{
  struct in_addr addr;

  for (;;)
    {
      addr.s_addr = htonl (LINKLOCAL_ADDR |
                           (((uint32_t) abs ((int) random ())
                             % 0xFD00) + 0x0100));
      errno = 0;
      if (! arp_claim (iface, addr))
        break;
      /* Our ARP may have been interrupted */
      if (errno)
        return (-1);
    }

  dhcp->address.s_addr = addr.s_addr;
  dhcp->netmask.s_addr = htonl (LINKLOCAL_MASK);
  dhcp->broadcast.s_addr = htonl (LINKLOCAL_BRDC);

  /* Finally configure some DHCP like lease times */
  dhcp->leasetime = IPV4LL_LEASETIME;
  dhcp->renewaltime = (dhcp->leasetime * 0.5);
  dhcp->rebindtime = (dhcp->leasetime * 0.875);

  return (0);
}

#endif