raw.c

代码在ti的c67系列单片机上实现了完整的TCPIP协议栈

//--------------------------------------------------------------------------
// Ip Stack
//--------------------------------------------------------------------------
// RAW.C
//
// RAW General Functions
//
// Author: Michael A. Denio
// Copyright 1999 by Texas Instruments Inc.
//-------------------------------------------------------------------------
#include <stkmain.h>

// Private and Public Globals
RAWSTATS raws;                      // Stats

#define RAW_MSS_DEFAULT     1500    // Default Max seg size (including IP)

//--------------------------------------------------------------------
// RawOutput()
//
// Called when RAW packet should be sent
//--------------------------------------------------------------------
int RawOutput( HANDLE hSock, UINT8 *buf, INT32 size, INT32 *pRetSize)
{
    HANDLE      hPkt,hFrag,hRoute,hIFTx;
    UINT8       *pb;
    uint        Offset;
    INT32       mss;
    int         error;

    //
    // Bound the size to something we can handle
    //
    // We'll try and get the MTU from the route, then the egress IF,
    // or finally we just assume a default.
    //
    if( (hRoute = SockGetRoute( hSock )) )
    {
        mss = (INT32)RtGetMTU( hRoute );
        hIFTx = 0;
    }
    else if( (hIFTx = SockGetIFTx( hSock )) )
        mss = (INT32)IFGetMTU( hIFTx );
    else
        mss = RAW_MSS_DEFAULT;

    mss -= SockGetIpHdrSize(hSock);     // Sub off IpHdr (if any)

    if( size > mss )
        return( EMSGSIZE );

    //
    // Create the packet
    //
    if( !(hPkt = SockCreatePacket( hSock, (uint)size, 0 )) )
    {
        raws.dwSndNoPacket++;
        return( ENOBUFS );
    }

    // Get the frag
    hFrag = PktGetFrag( hPkt );

    // Get the buffer parameters
    pb = FragGetBufParams( hFrag, 0, 0, &Offset );

    // Copy the data
    mmCopy( (pb + Offset + PktGetSizeNet(hPkt)), buf, (uint)size );

    // Indicate the preferred route and IF
    PktSetRoute( hPkt, hRoute );
    PktSetIFTx( hPkt, hIFTx );

    // Count it
    raws.dwSndTotal++;

    // Send the packet
    error=(int)IPTxPacket(hPkt,SockGetOptionFlags(hSock)&FLG_IPTX_SOSUPPORTED);

    if( !error )
        *pRetSize = size;

    return( error );
}

//--------------------------------------------------------------------
// RawInput()
//
// Rx RAW Packet
//--------------------------------------------------------------------
void RawInput( HANDLE hPkt )
{
    HANDLE     hFrag,hFragCopy,hSock,hSBRx,hIFTx;
    uint       w,Offset,Valid,RawLen,fBcast = 0;
    IPN        dwIPSrc,dwIPDst;
    UINT8      *pb;
    IPHDR      *pIpHdr;

    if( !(hFrag = PktGetFrag( hPkt )) )
    {
        DbgPrintf(DBG_ERROR,"RawInput: No frag data");
        PktFree( hPkt );
        return;
    }

    // Get the size of the IP Header and pointer to our data
    w = PktGetFlags( hPkt );
    if( !(w & FLG_PKT_IP_VALID) || (w & FLG_PKT_LLC_VALID) )
    {
        DbgPrintf(DBG_ERROR,"RawInput: Bad packet");
        PktFree( hPkt );
        return;
    }

    // Get the buffer parameters
    pb = FragGetBufParams( hFrag, 0, &Valid, &Offset );

    // Assign an IP header pointer
    pIpHdr = (IPHDR *)(pb + Offset);

    // Count the total number of packets in
    raws.dwRcvTotal++;

    // Get the total length of the message
    RawLen = (uint)(HNC16( pIpHdr->TotalLen ));

    // Get source and destination
    dwIPSrc = RdNet32(&pIpHdr->dwIPSrc);
    dwIPDst = RdNet32(&pIpHdr->dwIPDst);

    // Set the Frag Parms to hand off to a SB
    FragSetAux1( hFrag, 0x10000 );
    FragSetAux2( hFrag, dwIPSrc );
    FragSetBufParams( hFrag, RawLen, Offset );


    // Cache whether we are doing BROADCAST/MULTICAST
    if( dwIPDst == INADDR_BROADCAST || IN_MULTICAST( dwIPDst ) ||
            (PktGetFlags(hPkt) & (FLG_PKT_MACMCAST|FLG_PKT_MACBCAST)) )
        fBcast = 1;

    // We have to copy the frag for each socket with a matchng PCB
    hSock = 0;
    while( (hSock = SockPcbResolveChain( hSock, SOCKPROT_RAW, pIpHdr->Protocol,
                                         dwIPDst, 0, dwIPSrc, 0)) )
    {
        // Filter Broadcast and Multicast
        if( fBcast )
        {
            // Get the broadcast IF of this socket
            hIFTx = SockGetIFTx( hSock );

            // If there is a specified BCAST device, and the packet's
            // Rx device doesn't match it, then we ignore the packet
            if( hIFTx && ( hIFTx != PktGetIFRx(hPkt) ) )
                continue;
        }

        // Get the Linear Receive Buffer
        hSBRx = SockGetRx( hSock );

        if( SBGetSpace( hSBRx ) < (INT32)RawLen )
            raws.dwRcvFull++;
        else if( hFragCopy = FragCopy( hFrag ) )
        {
            // Give the frag to the SB
            SBWrite( hSBRx, (INT32)RawLen, 0, hFragCopy );

            // Notify the Socket
            SockNotify( hSock, SOCK_NOTIFY_RCVDATA );
        }
    }

    PktFree( hPkt );
    return;
}