/*! \file icmp.c \brief ICMP Protocol Library. */
//*****************************************************************************
//
// File Name	: 'icmp.c'
// Title		: ICMP (Internet Control Message Protocol) Protocol Library
// Author		: Pascal Stang
// Created		: 9/10/2004
// Revised		: 7/3/2005
// Version		: 0.1
// Target MCU	: Atmel AVR series
// Editor Tabs	: 4
//
//*****************************************************************************

#include "net.h"
#include "nic.h"
#include "arp.h"
#include "icmp.h"

#include "HardwareSerial.h"
#include "debug.h"

#ifdef ICMP_DEBUG_PRINT
#include <avr/pgmspace.h>
#include "programStrings.h"
#include "HardwareSerial.h"
#endif

#ifdef NET_CHECKSUM_DEBUG
#include "enc28j60.h"
#endif

// functions
void icmpInit(void)
{
	
}

void icmpIpIn(icmpip_hdr* packet)
{
	// check ICMP type
	switch(packet->icmp.type)
	{
	case ICMP_TYPE_ECHOREQUEST:
		// echo request
		icmpEchoRequest(packet);
		break;
	default:
		break;
	}
}

void icmpEchoRequest(icmpip_hdr* packet)
{
	uint32_t tempIp;
	uint16_t tempId;
	
	// change type to reply
	packet->icmp.type = ICMP_TYPE_ECHOREPLY;
	
	// recalculate checksum
	packet->icmp.icmpchksum = 0x0000;
	packet->icmp.icmpchksum	= nicGetChecksum((uint8_t*)&packet->icmp, htons(packet->ip.len)-IP_HEADER_LEN);
	
	#ifdef NET_CHECKSUM_DEBUG
		SPrintln(" ");
		SPrint("Hardware Checksum: 0x");
		Serial.println((uint16_t)HTONS(packet->icmp.icmpchksum), HEX);
	#endif
	
	// return to sender
	tempIp = packet->ip.destipaddr;
	packet->ip.destipaddr = packet->ip.srcipaddr;
	packet->ip.srcipaddr = tempIp;
	
	// add ethernet routing
	arpIpOut((struct netEthIpHeader*)(((u08*)packet)-ETH_HEADER_LEN), 0);
	
	// debugging
	#if NET_DEBUG >= 2
		icmpPrintHeader(packet);
		debugPrintHexTable(htons(packet->ip.len), (u08*)packet);
	#endif
	
	// send it (packet->ip.len+ETH_HEADER_LEN
	nicSend(htons(packet->ip.len)+ETH_HEADER_LEN, (((uint8_t*)packet)-ETH_HEADER_LEN));
}

#ifdef ICMP_DEBUG_PRINT
void icmpPrintHeader(icmpip_hdr* packet)
{
	SPrint("ICMP Packet:\r\n");
	// print source IP address
	SPrint("SrcIpAddr: ");	netPrintIPAddr(htonl(packet->ip.srcipaddr));	Serial.println();
	// print dest IP address
	SPrint("DstIpAddr: ");	netPrintIPAddr(htonl(packet->ip.destipaddr));	Serial.println();
	// print type
	SPrint("Type   : ");
	switch(packet->icmp.type)
	{
	case ICMP_TYPE_ECHOREQUEST:		SPrint("ECHO REQUEST"); break;
	case ICMP_TYPE_ECHOREPLY:		SPrint("ECHO REPLY"); break;
	default:						SPrint("UNKNOWN"); break;
	}
	Serial.println();
	// print code
	SPrint("Code   : 0x");	Serial.print(packet->icmp.icode);			Serial.println();
}
#endif