/*
 * COPYRIGHT:   See COPYING in the top level directory
 * PROJECT:     ReactOS TCP/IP protocol driver
 * FILE:        tcpip/buffer.c
 * PURPOSE:     Miscellaneous operations on NDIS_BUFFERs and packets.
 * PROGRAMMERS: Casper S. Hornstrup (chorns@users.sourceforge.net)
 * REVISIONS:
 *   CSH 01/08-2000 Created
 */

#include "precomp.h"

static inline
INT SkipToOffset(
    PNDIS_BUFFER Buffer,
    UINT Offset,
    PCHAR *Data,
    PUINT Size)
/*
 * FUNCTION: Skip Offset bytes into a buffer chain
 * ARGUMENTS:
 *     Buffer = Pointer to NDIS buffer
 *     Offset = Number of bytes to skip
 *     Data   = Address of a pointer that on return will contain the
 *              address of the offset in the buffer
 *     Size   = Address of a pointer that on return will contain the
 *              size of the destination buffer
 * RETURNS:
 *     Offset into buffer, -1 if buffer chain was smaller than Offset bytes
 * NOTES:
 *     Buffer may be NULL
 */
{
    for (;;) {

        if (!Buffer)
            return -1;

        NdisQueryBuffer(Buffer, (PVOID)Data, Size);

        if (Offset < *Size) {
            *Data = (PCHAR)((ULONG_PTR) *Data + Offset);
            *Size              -= Offset;
            break;
        }

        Offset -= *Size;

        NdisGetNextBuffer(Buffer, &Buffer);
    }

    return Offset;
}


UINT CopyBufferToBufferChain(
    PNDIS_BUFFER DstBuffer,
    UINT DstOffset,
    PCHAR SrcData,
    UINT Length)
/*
 * FUNCTION: Copies data from a buffer to an NDIS buffer chain
 * ARGUMENTS:
 *     DstBuffer = Pointer to destination NDIS buffer
 *     DstOffset = Destination start offset
 *     SrcData   = Pointer to source buffer
 *     Length    = Number of bytes to copy
 * RETURNS:
 *     Number of bytes copied to destination buffer
 * NOTES:
 *     The number of bytes copied may be limited by the destination
 *     buffer size
 */
{
    UINT BytesCopied, BytesToCopy, DstSize;
    PCHAR DstData;

    TI_DbgPrint(DEBUG_PBUFFER, ("DstBuffer (0x%X)  DstOffset (0x%X)  SrcData (0x%X)  Length (%d)\n", DstBuffer, DstOffset, SrcData, Length));

    /* Skip DstOffset bytes in the destination buffer chain */
    if (SkipToOffset(DstBuffer, DstOffset, &DstData, &DstSize) == -1)
        return 0;

    /* Start copying the data */
    BytesCopied = 0;
    for (;;) {
        BytesToCopy = MIN(DstSize, Length);

        RtlCopyMemory((PVOID)DstData, (PVOID)SrcData, BytesToCopy);
        BytesCopied += BytesToCopy;
        SrcData      = (PCHAR)((ULONG_PTR)SrcData + BytesToCopy);

        Length -= BytesToCopy;
        if (Length == 0)
            break;

        DstSize -= BytesToCopy;
        if (DstSize == 0) {
            /* No more bytes in destination buffer. Proceed to
               the next buffer in the destination buffer chain */
            NdisGetNextBuffer(DstBuffer, &DstBuffer);
            if (!DstBuffer)
                break;

            NdisQueryBuffer(DstBuffer, (PVOID)&DstData, &DstSize);
        }
    }

    return BytesCopied;
}


UINT CopyBufferChainToBuffer(
    PCHAR DstData,
    PNDIS_BUFFER SrcBuffer,
    UINT SrcOffset,
    UINT Length)
/*
 * FUNCTION: Copies data from an NDIS buffer chain to a buffer
 * ARGUMENTS:
 *     DstData   = Pointer to destination buffer
 *     SrcBuffer = Pointer to source NDIS buffer
 *     SrcOffset = Source start offset
 *     Length    = Number of bytes to copy
 * RETURNS:
 *     Number of bytes copied to destination buffer
 * NOTES:
 *     The number of bytes copied may be limited by the source
 *     buffer size
 */
{
    UINT BytesCopied, BytesToCopy, SrcSize;
    PCHAR SrcData;

    TI_DbgPrint(DEBUG_PBUFFER, ("DstData 0x%X  SrcBuffer 0x%X  SrcOffset 0x%X  Length %d\n",DstData,SrcBuffer, SrcOffset, Length));

    /* Skip SrcOffset bytes in the source buffer chain */
    if (SkipToOffset(SrcBuffer, SrcOffset, &SrcData, &SrcSize) == -1)
        return 0;

    /* Start copying the data */
    BytesCopied = 0;
    for (;;) {
        BytesToCopy = MIN(SrcSize, Length);

        TI_DbgPrint(DEBUG_PBUFFER, ("Copying (%d) bytes from 0x%X to 0x%X\n", BytesToCopy, SrcData, DstData));

        RtlCopyMemory((PVOID)DstData, (PVOID)SrcData, BytesToCopy);
        BytesCopied += BytesToCopy;
        DstData      = (PCHAR)((ULONG_PTR)DstData + BytesToCopy);

        Length -= BytesToCopy;
        if (Length == 0)
            break;

        SrcSize -= BytesToCopy;
        if (SrcSize == 0) {
            /* No more bytes in source buffer. Proceed to
               the next buffer in the source buffer chain */
            NdisGetNextBuffer(SrcBuffer, &SrcBuffer);
            if (!SrcBuffer)
                break;

            NdisQueryBuffer(SrcBuffer, (PVOID)&SrcData, &SrcSize);
        }
    }

    return BytesCopied;
}


UINT CopyPacketToBuffer(
    PCHAR DstData,
    PNDIS_PACKET SrcPacket,
    UINT SrcOffset,
    UINT Length)
/*
 * FUNCTION: Copies data from an NDIS packet to a buffer
 * ARGUMENTS:
 *     DstData   = Pointer to destination buffer
 *     SrcPacket = Pointer to source NDIS packet
 *     SrcOffset = Source start offset
 *     Length    = Number of bytes to copy
 * RETURNS:
 *     Number of bytes copied to destination buffer
 * NOTES:
 *     The number of bytes copied may be limited by the source
 *     buffer size
 */
{
    PNDIS_BUFFER FirstBuffer;
    PVOID Address;
    UINT FirstLength;
    UINT TotalLength;

    TI_DbgPrint(DEBUG_PBUFFER, ("DstData (0x%X)  SrcPacket (0x%X)  SrcOffset (0x%X)  Length (%d)\n", DstData, SrcPacket, SrcOffset, Length));

    NdisGetFirstBufferFromPacket(SrcPacket,
                                 &FirstBuffer,
                                 &Address,
                                 &FirstLength,
                                 &TotalLength);

    return CopyBufferChainToBuffer(DstData, FirstBuffer, SrcOffset, Length);
}


UINT CopyPacketToBufferChain(
    PNDIS_BUFFER DstBuffer,
    UINT DstOffset,
    PNDIS_PACKET SrcPacket,
    UINT SrcOffset,
    UINT Length)
/*
 * FUNCTION: Copies data from an NDIS packet to an NDIS buffer chain
 * ARGUMENTS:
 *     DstBuffer = Pointer to destination NDIS buffer
 *     DstOffset = Destination start offset
 *     SrcPacket = Pointer to source NDIS packet
 *     SrcOffset = Source start offset
 *     Length    = Number of bytes to copy
 * RETURNS:
 *     Number of bytes copied to destination buffer
 * NOTES:
 *     The number of bytes copied may be limited by the source and
 *     destination buffer sizes
 */
{
    PNDIS_BUFFER SrcBuffer;
    PCHAR DstData, SrcData;
    UINT DstSize, SrcSize;
    UINT Count, Total;

    TI_DbgPrint(DEBUG_PBUFFER, ("DstBuffer (0x%X)  DstOffset (0x%X)  SrcPacket (0x%X)  SrcOffset (0x%X)  Length (%d)\n", DstBuffer, DstOffset, SrcPacket, SrcOffset, Length));

    /* Skip DstOffset bytes in the destination buffer chain */
    NdisQueryBuffer(DstBuffer, (PVOID)&DstData, &DstSize);
    if (SkipToOffset(DstBuffer, DstOffset, &DstData, &DstSize) == -1)
        return 0;

    /* Skip SrcOffset bytes in the source packet */
    NdisGetFirstBufferFromPacket(SrcPacket, &SrcBuffer, (PVOID)&SrcData, &SrcSize, &Total);
    if (SkipToOffset(SrcBuffer, SrcOffset, &SrcData, &SrcSize) == -1)
        return 0;

    /* Copy the data */
    for (Total = 0;;) {
        /* Find out how many bytes we can copy at one time */
        if (Length < SrcSize)
            Count = Length;
        else
            Count = SrcSize;
        if (DstSize < Count)
            Count = DstSize;

        RtlCopyMemory((PVOID)DstData, (PVOID)SrcData, Count);

        Total  += Count;
        Length -= Count;
        if (Length == 0)
            break;

        DstSize -= Count;
        if (DstSize == 0) {
            /* No more bytes in destination buffer. Proceed to
               the next buffer in the destination buffer chain */
            NdisGetNextBuffer(DstBuffer, &DstBuffer);
            if (!DstBuffer)
                break;

            NdisQueryBuffer(DstBuffer, (PVOID)&DstData, &DstSize);
        }

        SrcSize -= Count;
        if (SrcSize == 0) {
            /* No more bytes in source buffer. Proceed to
               the next buffer in the source buffer chain */
            NdisGetNextBuffer(SrcBuffer, &SrcBuffer);
            if (!SrcBuffer)
                break;

            NdisQueryBuffer(SrcBuffer, (PVOID)&SrcData, &SrcSize);
        }
    }

    return Total;
}


UINT ResizePacket(
    PNDIS_PACKET Packet,
    UINT Size)
/*
 * FUNCTION: Resizes an NDIS packet
 * ARGUMENTS:
 *     Packet = Pointer to packet
 *     Size   = Number of bytes in first buffer
 * RETURNS:
 *     Previous size of first buffer
 */
{
    PNDIS_BUFFER NdisBuffer;
    UINT OldSize;

    NdisQueryPacket(Packet, NULL, NULL, &NdisBuffer, NULL);

    OldSize = NdisBuffer->ByteCount;

    if (Size != OldSize)
        NdisBuffer->ByteCount = Size;

    return OldSize;
}

void GetDataPtr( PNDIS_PACKET Packet,
		 UINT Offset,
		 PCHAR *DataOut,
		 PUINT Size ) {
    PNDIS_BUFFER Buffer;

    NdisQueryPacket(Packet, NULL, NULL, &Buffer, NULL);
    if( !Buffer ) return;
    SkipToOffset( Buffer, Offset, DataOut, Size );
}

NDIS_STATUS AllocatePacketWithBuffer( PNDIS_PACKET *NdisPacket,
				      PCHAR Data, UINT Len ) {
    PNDIS_PACKET Packet;
    PNDIS_BUFFER Buffer;
    NDIS_STATUS Status;
    PCHAR NewData;

    NewData = ExAllocatePoolWithTag( NonPagedPool, Len, PACKET_BUFFER_TAG );
    if( !NewData ) return NDIS_STATUS_RESOURCES;

    if( Data ) RtlCopyMemory(NewData, Data, Len);

    NdisAllocatePacket( &Status, &Packet, GlobalPacketPool );
    if( Status != NDIS_STATUS_SUCCESS ) {
	ExFreePoolWithTag( NewData, PACKET_BUFFER_TAG );
	return Status;
    }

    NdisAllocateBuffer( &Status, &Buffer, GlobalBufferPool, NewData, Len );
    if( Status != NDIS_STATUS_SUCCESS ) {
	ExFreePoolWithTag( NewData, PACKET_BUFFER_TAG );
	FreeNdisPacket( Packet );
	return Status;
    }

    NdisChainBufferAtFront( Packet, Buffer );
    *NdisPacket = Packet;

    return NDIS_STATUS_SUCCESS;
}


VOID FreeNdisPacket
( PNDIS_PACKET Packet )
/*
 * FUNCTION: Frees an NDIS packet
 * ARGUMENTS:
 *     Packet = Pointer to NDIS packet to be freed
 */
{
    PNDIS_BUFFER Buffer, NextBuffer;

    TI_DbgPrint(DEBUG_PBUFFER, ("Packet (0x%X)\n", Packet));

    /* Free all the buffers in the packet first */
    NdisQueryPacket(Packet, NULL, NULL, &Buffer, NULL);
    for (; Buffer != NULL; Buffer = NextBuffer) {
        PVOID Data;
        UINT Length;

        NdisGetNextBuffer(Buffer, &NextBuffer);
        NdisQueryBuffer(Buffer, &Data, &Length);
	TI_DbgPrint(DEBUG_PBUFFER, ("Freeing ndis buffer (0x%X)\n", Buffer));
        NdisFreeBuffer(Buffer);
	TI_DbgPrint(DEBUG_PBUFFER, ("Freeing exal buffer (0x%X)\n", Data));
        ExFreePoolWithTag(Data, PACKET_BUFFER_TAG);
    }

    /* Finally free the NDIS packet descriptor */
    NdisFreePacket(Packet);
}
