/****************************************************************************
 * net/utils/net_icmpchksum.c
 *
 *   Copyright (C) 2007-2010, 2012, 2014-2015 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * 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.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT OWNER 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>
#ifdef CONFIG_NET

#include <stdint.h>
#include <debug.h>

#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/icmp.h>

#include "utils/utils.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define IPv4BUF     ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define ICMPBUF(hl) ((FAR struct icmp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + (hl)])
#define ICMPv6BUF   ((struct icmp_ipv6hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: icmp_chksum
 *
 * Description:
 *   Calculate the checksum of the ICMP message
 *
 ****************************************************************************/

#if defined(CONFIG_NET_ICMP) && defined(CONFIG_NET_ICMP_SOCKET)
uint16_t icmp_chksum(FAR struct net_driver_s *dev, int len)
{
  FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
  FAR struct icmp_hdr_s *icmp;
  uint16_t iphdrlen;

  /* Get the IP header length (accounting for possible options). */

  iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2;

  /* The ICMP header immediately follows the IP header */

  icmp = ICMPBUF(iphdrlen);
  return net_chksum((FAR uint16_t *)&icmp->type, len);
}
#endif /* CONFIG_NET_ICMP && CONFIG_NET_ICMP_SOCKET */

/****************************************************************************
 * Name: icmpv6_chksum
 *
 * Description:
 *   Calculate the checksum of the ICMPv6 message
 *
 ****************************************************************************/

#ifdef CONFIG_NET_ICMPv6
uint16_t icmpv6_chksum(FAR struct net_driver_s *dev, unsigned int iplen)
{
  return ipv6_upperlayer_chksum(dev, IP_PROTO_ICMP6, iplen);
}
#endif

#endif /* CONFIG_NET */