NdisQueryBufferOffset (Windows Embedded CE 6.0)

1/6/2010

This function retrieves the base virtual address of the range specified in a specified buffer descriptor.

Syntax

VOID NdisQueryBufferOffset(
  PNDIS_BUFFER Buffer,
  PUINT Offset,
  PUINT Length
);

Parameters

• Buffer
  [in] Pointer to the buffer descriptor.

• Offset
  [out] Pointer to a caller-supplied variable in which this function returns the 0-based byte offset within the physical page containing the buffer.

• Length
  [out] Pointer to a caller-supplied variable in which this function returns the size, in bytes, of the given buffer.

Return Value

None.

Remarks

This function returns the offset within a physical page at which a given buffer begins. Usually, the buffer descriptor is part of a packet chain.

This function runs faster than the NdisQueryBuffer function. NDIS drivers call this function in situations in which they need to constrain packets by certain criteria. For example, this function can be used to determine if a buffer crosses a page boundary, if it is odd-byte aligned, and so on.

Requirements

See Also

Reference

NDIS Library Functions
NdisAllocateBuffer
NdisQueryBuffer
NdisUnchainBufferAtBack
NdisUnchainBufferAtFront