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NdisAllocateBuffer function (ndis.h)

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Note   NDIS 5. x has been deprecated and is superseded by NDIS 6. x. For new NDIS driver development, see Network Drivers Starting with Windows Vista. For information about porting NDIS 5. x drivers to NDIS 6. x, see Porting NDIS 5.x Drivers to NDIS 6.0.

NdisAllocateBuffer creates a buffer descriptor mapping a specified virtual (sub)range within an already allocated, nonpaged memory block.

Syntax

void NdisAllocateBuffer(
  [out]          PNDIS_STATUS Status,
  [out]          PNDIS_BUFFER *Buffer,
  [in, optional] NDIS_HANDLE  PoolHandle,
  [in]           PVOID        VirtualAddress,
  [in]           UINT         Length
);

Parameters

[out] Status

Pointer to a caller-supplied variable in which this function returns the final status of the buffer allocation, which is NDIS_STATUS_SUCCESS if it returned a valid buffer descriptor pointer at Buffer and otherwise NDIS_STATUS_FAILURE.

[out] Buffer

Pointer to a caller-supplied variable in which this function returns a pointer to the allocated buffer descriptor.

[in, optional] PoolHandle

Specifies the handle returned by a preceding call to NdisAllocateBufferPool.

[in] VirtualAddress

Pointer to the base virtual address of previously allocated system-space memory to be mapped in the returned buffer descriptor.

[in] Length

Specifies the number of bytes to be mapped.

Return value

None

Remarks

Return value: None

NdisAllocateBuffer allocates storage for and initializes a buffer descriptor to map a specified range of previously allocated memory, such as memory used for a packet header or a NIC receive buffer.

Buffer descriptor allocation draws on the buffer pool that NdisAllocateBufferPool creates. A driver can call NdisAllocateBuffer as many times as necessary to allocate the buffer descriptors that it requires if it called NdisAllocateBufferPool during initialization.

All lower-level NDIS drivers must allocate all buffer descriptors that they chain to packets from buffer pool. Only highest-level protocol drivers can be given OS-dependent descriptors mapping virtual memory ranges, and, if these memory descriptors are equivalent to NDIS buffer descriptors, a highest-level protocol can pass such descriptors as parameters to NdisXxx functions.

Requirements

Requirement Value
Header ndis.h (include Ndis.h)
Library Ndis.lib
IRQL IRQL <= DISPATCH_LEVEL

See also