/home/jander/temp/etherdune/ICMP.cpp

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// EtherDune ICMP Abstract base class
// Author: Javier Peletier <jm@friendev.com>
// Summary: Implements common ICMP packet building routines and ICMP checksum
// Summary: Used as base class for ICMP Echo (ping)
//
// Copyright (c) 2015 All Rights Reserved, http://friendev.com
//
// This source is subject to the GPLv2 license.
// Please see the License.txt file for more information.
// All other rights reserved.
//
// THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY 
// KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.

#include "ICMP.h"
#include "Checksum.h"

#define AC_LOGLEVEL 2
#include <ACLog.h>
ACROSS_MODULE("ICMP");

bool ICMP::onPacketReceived()
{
    if (!(packet.ip.protocol == IP_PROTO_ICMP))
    {
        return false;
    }
    

    return onICMPMessage();

}

bool ICMP::loadAll()
{
    NetworkService::loadAll(); //bring in the rest of the packet.

#if ENABLE_ICMP_RX_CHECKSUM

    calcICMPChecksum();
    if (packet.icmp.checksum != 0)
        return false; //checksum error, drop packet

#endif

    return true;
}

void ICMP::calcICMPChecksum()
{
    packet.icmp.checksum = ~Checksum::calc(packet.ip.totalLength - sizeof(IPHeader), (uint8_t*)&packet.icmp);
}

void ICMP::sendICMPPacket(const IPAddress& targetIP, uint16_t dataLength)
{
    ACASSERT(dataLength < EtherDune_BUFFER_SIZE - sizeof(EthernetHeader) - sizeof(IPHeader) - sizeof(ICMPHeader), "ICMP packet too big. Actual size=%d, max size=%d", dataLength, EtherDune_BUFFER_SIZE - sizeof(EthernetHeader) - sizeof(IPHeader) - sizeof(ICMPHeader));

    packet.ip.protocol = IP_PROTO_ICMP;
    dataLength += sizeof(IPHeader) + sizeof(ICMPHeader);
    packet.ip.totalLength = dataLength;
    prepareIPPacket(targetIP);

    packet.icmp.checksum = 0;
    calcICMPChecksum();
    sendIPPacket(dataLength);


}