StackTsk.c

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/*********************************************************************
 * Software License Agreement
 *
 * Copyright (C) 2002-2008 Microchip Technology Inc.  All rights 
 * reserved.
 *
 * Microchip licenses to you the right to use, modify, copy, and 
 * distribute: 
 * (i)  the Software when embedded on a Microchip microcontroller or 
 *      digital signal controller product ("Device") which is 
 *      integrated into Licensee's product; or
 * (ii) ONLY the Software driver source files ENC28J60.c and 
 *      ENC28J60.h ported to a non-Microchip device used in 
 *      conjunction with a Microchip ethernet controller for the 
 *      sole purpose of interfacing with the ethernet controller. 
 *
 * You should refer to the license agreement accompanying this 
 * Software for additional information regarding your rights and 
 * obligations.
 *
 * THE SOFTWARE AND DOCUMENTATION ARE PROVIDED "AS IS" WITHOUT 
 * WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT 
 * LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A 
 * PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT SHALL 
 * MICROCHIP BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR 
 * CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA, COST OF 
 * PROCUREMENT OF SUBSTITUTE GOODS, TECHNOLOGY OR SERVICES, ANY CLAIMS 
 * BY THIRD PARTIES (INCLUDING BUT NOT LIMITED TO ANY DEFENSE 
 * THEREOF), ANY CLAIMS FOR INDEMNITY OR CONTRIBUTION, OR OTHER 
 * SIMILAR COSTS, WHETHER ASSERTED ON THE BASIS OF CONTRACT, TORT 
 * (INCLUDING NEGLIGENCE), BREACH OF WARRANTY, OR OTHERWISE.
 *
 *
 * Author               Date        Comment
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Nilesh Rajbharti     8/14/01     Original (Rev. 1.0)
 * Nilesh Rajbharti     2/9/02      Cleanup
 * Nilesh Rajbharti     5/22/02     Rev 2.0 (See version.log for detail)
 * Nilesh Rajbharti     12/5/02     Modified UDPProcess() and TCPProcess()
 *                                  to include localIP as third param.
 *                                  This was done to allow these functions
 *                                  to calculate checksum correctly.
 * Nilesh Rajbharti     7/26/04     Added code in StackTask() to not
 *                                  clear statically IP address if link is
 *                                  removed and DHCP module is disabled
 *                                  at runtime.
 * Howard Schlunder     03/16/07    Rewrote stack manager to be linear
********************************************************************/
#define __STACKTSK_C

#include "TCPIP.h"
#include "Reboot.h" // MODIFIX: added this include.

// MODIFIX: Removed external symbol "myDHCPBindCount"

// Stack FSM states.
typedef enum _SM_STACK
{
    SM_STACK_IDLE,
    SM_STACK_MAC,
    SM_STACK_IP,
    SM_STACK_ARP,
    SM_STACK_TCP,
    SM_STACK_UDP
} SM_STACK;
static SM_STACK smStack;

NODE_INFO remoteNode;



/*********************************************************************
 * Function:        void StackInit(void)
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          Stack and its componets are initialized
 *
 * Side Effects:    None
 *
 * Note:            This function must be called before any of the
 *                  stack or its component routines are used.
 *
 ********************************************************************/
void StackInit(void)
{
    smStack = SM_STACK_IDLE;

    // MODIFIX: Removed IP gleaning functionality.

    // Seed the rand() function
    srand(GenerateRandomDWORD());

//    MACInit();

    ARPInit();

    UDPInit();

    TCPInit();

    // MODIFIX: Removed Berkeley handling.

    // Initialize the HTTP module for the eWicht Webpage.
    HTTPInit();

    // MODIFIX: Removed DHCP handling because its handled completely from
    //          the eWicht application.

    // MODIFIX: Removed all other parts not used by the eWicht application.
}


/*********************************************************************
 * Function:        void StackTask(void)
 *
 * PreCondition:    StackInit() is already called.
 *
 * Input:           None
 *
 * Output:          Stack FSM is executed.
 *
 * Side Effects:    None
 *
 * Note:            This FSM checks for new incoming packets,
 *                  and routes it to appropriate stack components.
 *                  It also performs timed operations.
 *
 *                  This function must be called periodically to
 *                  ensure timely responses.
 *
 ********************************************************************/
void StackTask(void)
{
    WORD dataCount;
    IP_ADDR tempLocalIP;
    BYTE cFrameType;
    BYTE cIPFrameType;

    // MODIFIX: Modified DHCP handling because its handled from the eWicht
    //          application.
    if(sPCommonConfig.Flags.bIsDHCPEnabled)
    {
        // DHCP must be called all the time even after IP configuration is
        // discovered.
        // DHCP has to account lease expiration time and renew the configuration
        // time.
        DHCPTask();
    }


    // Perform all TCP time related tasks (retransmit, send acknowledge, close connection, etc)
    TCPTick();

    UDPTask();

    // Process as many incomming packets as we can
    while(1)
    {
        // MODIFIX: Removed the STACK_USE_RANDOM functionality.

        // We are about to fetch a new packet, make sure that the 
        // UDP module knows that any old RX data it has laying 
        // around will now be gone.
        UDPDiscard();

        // Fetch a packet (throws old one away, if not thrown away 
        // yet)
        if(!MACGetHeader(&remoteNode.MACAddr, &cFrameType))
            break;

        // Dispatch the packet to the appropriate handler
        switch(cFrameType)
        {
            case MAC_ARP:
                ARPProcess();
                break;
    
            case MAC_IP:
                if(!IPGetHeader(&tempLocalIP, &remoteNode, &cIPFrameType, &dataCount))
                    break;

                if(cIPFrameType == IP_PROT_ICMP)
                {
                    // MODIFIX: Removed IP gleaning functionality.

                    // Process this ICMP packet if it the destination IP address matches our address or one of the broadcast IP addressees
                    // MODIFIX: Use the eWicht structure sIPConfig (4 times)
                    if( (tempLocalIP.Val == sIPConfig.MyIPAddr.Val) ||
                        (tempLocalIP.Val == 0xFFFFFFFF) ||
                        (tempLocalIP.Val == ((sIPConfig.MyIPAddr.Val & sIPConfig.MyMask.Val) | ~sIPConfig.MyMask.Val)))
                    {
                        ICMPProcess(&remoteNode, dataCount);
                    }
                    break;
                }
                
                if(cIPFrameType == IP_PROT_TCP)
                {
                    TCPProcess(&remoteNode, &tempLocalIP, dataCount);
                    break;
                }
                
                if(cIPFrameType == IP_PROT_UDP)
                {
                    // Stop processing packets if we came upon a UDP frame with application data in it
                    if (UDPProcess(&remoteNode, &tempLocalIP, dataCount))
                        return;
                }

                break;
        }
    }
}

/*********************************************************************
 * Function:        void StackApplications(void)
 *
 * PreCondition:    StackInit() is already called.
 *
 * Input:           None
 *
 * Output:          Calls all loaded application modules.
 *
 * Side Effects:    None
 *
 * Note:            This function must be called periodically to
 *                  ensure timely responses.
 *
 ********************************************************************/
void StackApplications(void)
{
    HTTPServer();

    RebootTask();

    // MODIFIX: Removed unneeded parts.
}

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