library

/*! \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 "global.h"
#include "net.h"
#include "nic.h"
#include "arp.h"
#include "icmp.h"

#include "rprintf.h"
#include "debug.h"

//extern void nicSend(unsigned int len, unsigned char* packet);

// global variables


// 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;
        
        // change type to reply
        packet->icmp.type = ICMP_TYPE_ECHOREPLY;
        // recalculate checksum
        packet->icmp.icmpchksum = 0;
        packet->icmp.icmpchksum = netChecksum((u08*)&packet->icmp, htons(packet->ip.len)-IP_HEADER_LEN);
        // 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, (((u08*)packet)-ETH_HEADER_LEN));
}

#ifdef ICMP_DEBUG_PRINT
void icmpPrintHeader(icmpip_hdr* packet)
{
        rprintfProgStrM("ICMP Packet:\r\n");
        // print source IP address
        rprintfProgStrM("SrcIpAddr: "); netPrintIPAddr(htonl(packet->ip.srcipaddr));    rprintfCRLF();
        // print dest IP address
        rprintfProgStrM("DstIpAddr: "); netPrintIPAddr(htonl(packet->ip.destipaddr));   rprintfCRLF();
        // print type
        rprintfProgStrM("Type   : ");
        switch(packet->icmp.type)
        {
        case ICMP_TYPE_ECHOREQUEST:             rprintfProgStrM("ECHO REQUEST"); break;
        case ICMP_TYPE_ECHOREPLY:               rprintfProgStrM("ECHO REPLY"); break;
        default:                                                rprintfProgStrM("UNKNOWN"); break;
        }
        rprintfCRLF();
        // print code
        rprintfProgStrM("Code   : 0x"); rprintfu08(packet->icmp.icode);                 rprintfCRLF();
}
#endif