Microsoft Internet Security and Acceleration Server 2000


The buffer object points to a reference-counted memory buffer and provides means of managing the buffer.

The following rules apply to these buffers:

The Send, SendTo, and Recv methods increment the reference count on the buffer. This reference is kept until CompleteAsyncIO returns. You must call Release for each AddRef that you called, and once more if you also created the buffer. Call AddRef if you keep a pointer to the buffer.

Methods in Vtable Order

IUnknown Methods Description
QueryInterface Returns pointers to supported interfaces.
AddRef Increments the reference count.
Release Decrements the reference count.

IFWXIOBuffer Methods Description
GetBufferAndSize Gets the actual buffer and its size.
SetDataSize Sets the actual size of the buffer that was used.
Append Appends a specified number of bytes of data to the buffer object.
ReadAt Reads a specified number of bytes starting at a specified offset from the beginning of the buffer.
SendToBuffer Appends data from this buffer to another buffer.
GetBufferSizes Gets the allocated and actual buffer sizes.


This interface is generally implemented by the Firewall service. You may want to implement IFWXIOBuffer in your filter if:


  Windows NT/2000: Requires Windows 2000.
  Version: Requires ISA Server 2000.
  Header: Wspfwext.idl.