Subversion Repositories HomeAutomation

/*********************************************************************

 *

 *                  ARP Module for Microchip TCP/IP Stack

 *

 *********************************************************************

 * FileName:        ARP.c

 * Dependencies:    string.h

 *                  stacktsk.h

 *                  helpers.h

 *                  arp.h

 *                  mac.h

 * Processor:       PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F

 * Complier:        Microchip C18 v3.02 or higher

 *                  Microchip C30 v2.01 or higher

 * Company:         Microchip Technology, Inc.

 *

 * Software License Agreement

 *

 * This software is owned by Microchip Technology Inc. ("Microchip")

 * and is supplied to you for use exclusively as described in the

 * associated software agreement.  This software is protected by

 * software and other intellectual property laws.  Any use in

 * violation of the software license may subject the user to criminal

 * sanctions as well as civil liability.  Copyright 2006 Microchip

 * Technology Inc.  All rights reserved.

 *

 * This software is provided "AS IS."  MICROCHIP DISCLAIMS ALL

 * WARRANTIES, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, NOT LIMITED

 * TO MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND

 * INFRINGEMENT.  Microchip shall in no event be liable for special,

 * incidental, or consequential damages.

 *

 *

 * Author               Date    Comment

 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 * Nilesh Rajbharti     5/1/01  Original        (Rev 1.0)

 * Nilesh Rajbharti     2/9/02  Cleanup

 * Nilesh Rajbharti     5/22/02 Rev 2.0 (See version.log for detail)

 ********************************************************************/

#include <string.h>

#include "..\Include\StackTsk.h"

#include "..\Include\Helpers.h"

#include "..\Include\ARP.h"

#include "..\Include\MAC.h"

// ARP Operation codes.

#define ARP_OPERATION_REQ       0x01u

#define ARP_OPERATION_RESP      0x02u

// ETHERNET packet type as defined by IEEE 802.3

#define HW_ETHERNET             (0x0001u)

#define ARP_IP                  (0x0800u)

// ARP packet

typedef struct _ARP_PACKET

{

    WORD        HardwareType;

    WORD        Protocol;

    BYTE        MACAddrLen;

    BYTE        ProtocolLen;

    WORD        Operation;

    MAC_ADDR    SenderMACAddr;

    IP_ADDR     SenderIPAddr;

    MAC_ADDR    TargetMACAddr;

    IP_ADDR     TargetIPAddr;

} ARP_PACKET;

// Helper function

static void SwapARPPacket(ARP_PACKET *p);

/*********************************************************************

 * Function:        BOOL ARPGet(NODE_INFO* remote, BYTE* opCode)

 *

 * PreCondition:    ARP packet is ready in MAC buffer.

 *

 * Input:           remote  - Remote node info

 *                  opCode  - Buffer to hold ARP op code.

 *

 * Output:          TRUE if a valid ARP packet was received.

 *                  FALSE otherwise.

 *

 * Side Effects:    None

 *

 * Overview:        None

 *

 * Note:            None

 ********************************************************************/

BOOL ARPGet(NODE_INFO *remote, BYTE *opCode)

{

    ARP_PACKET packet;

    MACGetArray((BYTE*)&packet, sizeof(packet));

    MACDiscardRx();

    SwapARPPacket(&packet);

    if ( packet.HardwareType != HW_ETHERNET     ||

         packet.MACAddrLen != sizeof(MAC_ADDR)  ||

         packet.ProtocolLen != sizeof(IP_ADDR) )

    {

         return FALSE;

    }

    if ( packet.Operation == ARP_OPERATION_RESP )

    {  

        *opCode = ARP_REPLY;

    }

    else if ( packet.Operation == ARP_OPERATION_REQ )

        *opCode = ARP_REQUEST;

    else

    {

        *opCode = ARP_UNKNOWN;

        return FALSE;

    }

    if(packet.TargetIPAddr.Val == AppConfig.MyIPAddr.Val)

    {

        remote->MACAddr     = packet.SenderMACAddr;

        remote->IPAddr      = packet.SenderIPAddr;

        return TRUE;

    }

    else

        return FALSE;

}

/*********************************************************************

 * Function:        BOOL ARPPut(NODE_INFO* more, BYTE opCode)

 *

 * PreCondition:    None

 *

 * Input:           remote  - Remote node info

 *                  opCode  - ARP op code to send

 *

 * Output:          TRUE - The ARP packet was generated properly

 *                  FALSE - Unable to allocate a TX buffer

 *

 * Side Effects:    None

 *

 * Overview:        None

 *

 * Note:            None

 ********************************************************************/

BOOL ARPPut(NODE_INFO *remote, BYTE opCode)

{

    ARP_PACKET packet;

    BUFFER MyTxBuffer = MACGetTxBuffer(TRUE);

    // Do not respond if there is no room to generate the ARP reply

    if(MyTxBuffer == INVALID_BUFFER)

        return FALSE;

    MACSetTxBuffer(MyTxBuffer, 0);

    packet.HardwareType             = HW_ETHERNET;

    packet.Protocol                 = ARP_IP;

    packet.MACAddrLen               = sizeof(MAC_ADDR);

    packet.ProtocolLen              = sizeof(IP_ADDR);

    if ( opCode == ARP_REQUEST )

    {

        packet.Operation            = ARP_OPERATION_REQ;

        packet.TargetMACAddr.v[0]   = 0xff;

        packet.TargetMACAddr.v[1]   = 0xff;

        packet.TargetMACAddr.v[2]   = 0xff;

        packet.TargetMACAddr.v[3]   = 0xff;

        packet.TargetMACAddr.v[4]   = 0xff;

        packet.TargetMACAddr.v[5]   = 0xff;

    }

    else

    {

        packet.Operation            = ARP_OPERATION_RESP;

        packet.TargetMACAddr        = remote->MACAddr;

    }

    packet.SenderMACAddr = AppConfig.MyMACAddr;

    packet.SenderIPAddr  = AppConfig.MyIPAddr;

    // Check to see if target is on same subnet, if not, find Gateway MAC.

    // Once we get Gateway MAC, all access to remote host will go through Gateway.

    if((packet.SenderIPAddr.Val ^ remote->IPAddr.Val) & AppConfig.MyMask.Val)

    {

        packet.TargetIPAddr = AppConfig.MyGateway;

    }

    else

        packet.TargetIPAddr = remote->IPAddr;

    SwapARPPacket(&packet);

    MACPutHeader(&packet.TargetMACAddr, MAC_ARP, sizeof(packet));

    MACPutArray((BYTE*)&packet, sizeof(packet));

    MACFlush();

    return TRUE;

}

/*********************************************************************

 * Function:        static void SwapARPPacket(ARP_PACKET* p)

 *

 * PreCondition:    None

 *

 * Input:           p   - ARP packet to be swapped.

 *

 * Output:          None

 *

 * Side Effects:    None

 *

 * Overview:        None

 *

 * Note:            None

 ********************************************************************/

static void SwapARPPacket(ARP_PACKET *p)

{

    p->HardwareType     = swaps(p->HardwareType);

    p->Protocol         = swaps(p->Protocol);

    p->Operation        = swaps(p->Operation);

}