Windows 2000 Network Drivers

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Windows 2000 Network Drivers

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Roadmap

• Microsoft Windows 2000 support Three basic types
  of kernel-mode network drivers
• Miniport NIC drivers
• A miniport driver directly manages a network
  interface card (NIC) and provides an interface to
  higher-level drivers.
• Intermediate drivers
• An intermediate protocol driver interfaces
  between upper-level protocol drivers, such as a
  legacy transport driver, and a miniport.
• Protocol drivers
• An upper level protocol driver implements a TDI
  interface, or possibly another application-specifi
  c interface at its upper-edge
• At its lower edge, this type of driver provides a
  protocol interface to pass packets to and receive
  incoming packets from the next-lower driver.

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Roadmap

• Another type of kernel-mode driver supported by
  Windows 2000
• filter-hook driver
• Filter packets
• Extends the functionality of the IP filter driver

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Windows 2000 Network Architecture and the OSI
Model

• Windows 2000 is Based on the OSI 7-layer
  networking model

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Windows 2000 Network Architecture and the OSI
Model

• Physical Layer
• involves the reception and transmission of the
  unstructured raw bit stream over a physical
  medium
• Implemented by the network interface card(NIC),
  its transceiver, and the medium to which the NIC
  is attached
• can include low-level network software

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Windows 2000 Network Architecture and the OSI
Model

• Data Link Layer
• LLC
• establishes and terminates logical links,
  controls frames flow, sequences frames,
  acknowledges frames, and retransmits
  unacknowledged frames.
• Implemented in the transport driver
• MAC
• manages access to the network media, checks frame
  errors, and manages address recognition of
  received frames.
• implemented in the network interface card (NIC)
• The NIC is controlled by a software device driver
  called the NIC driver.

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Windows 2000 Network Architecture and the OSI
Model

• Network Layer
• controls the operation of the subnet and
  determines the physical path the data should take
• Transport Layer
• ensure that messages are delivered error-free, in
  sequence, and with no loss or duplication
• In the Windows 2000 network architecture
• the LLC, Network, and Transport layer -gt
  transport drivers

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NDIS Drivers

• The Network Driver Interface Specification(NDIS)
  library
• abstracts the network hardware from network
  drivers
• specifies a standard interface between layered
  network drivers
• abstract lower-level drivers
• maintains state information and parameters for
  network drivers
• support
• Miniport drivers
• Intermediate drivers
• Protocol drivers

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NDIS Drivers
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NDIS Drivers

• NDIS Miniport Drivers(miniport NIC driver)
• two basic functions
• managing a NIC
• interfacing with higher-level drivers
• The NDIS library exports a full set of
  functions(NdisXXX functions) that encapsulate all
  the OS functions.
• Called by Miniport
• The miniport must export a set of entry
  points(MiniportXxx functions).
• Called by NDIS

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NDIS Drivers

• The interaction of miniport NIC drivers with NDIS
  and with higher-level drivers
• Send
• transport driver calls an NdisXxx functions.
• NDIS passes the packet to the miniport by calling
  the appropriate MiniportXxx function.
• The miniport driver then forwards the packet to
  the NIC by calling the appropriate NdisXxx
  functions.
• Receive
• NIC post a hardware interrupt.
• NDIS call MiniportXxx function
• The miniport sets up the transfer of data from
  the NIC and then indicates the presence of the
  received packet to bound higher-level drivers by
  calling the NdisXxx function.

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NDIS Drivers

• Connectionless miniport
• Serialized drivers
• rely on NDIS to serialize calls to their
  miniportXxx functions and to manage their send
  queues.
• Deserialized drivers
• serialize the operation of their own MiniportXxx
  functions
• queue internally all incoming send packets.
• connectionless network media Ethernet,
  FDDI,Token Ring.
• connection-oriendted network media ATM and ISDN
• Always deserialized.
• An NDIS miniport driver can have a non-NDIS lower
  edge

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NDIS Drivers

• NDIS Intermediate Drivers

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NDIS Drivers

• NDIS Intermediate Drivers
• At it lower edge, exposes protocol entry
  points(ProtocolXxx functions)
• At it upper edge, exposes miniport entry
  points(MiniportXxx functions)
• It does not actually manage a physical NIC
• it exports one or more virtual adapters.
• Intermediate drivers are typically used in the
  following ways
• To translate between different network media
• To filter packets
• To balance packet transmission across more than
  on NIC

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NDIS Drivers

• NDIS Protocol Drivers
• The highest driver in the NDIS drivers
• often used as the lowest-level driver in a
  transport driver that implements a transport
  protocol stack(TCP/IP, IPX).
• At its lower edge, a protocol driver interfaces
  with intermediate network drivers and miniport
  NIC drivers.
• Use NDIS funcions(NdisXxxx)
• export a set of entry points(ProtocolXxx
  functions)
• At its upper edge, a transport protocol driver
  has a private interface to a higher-level driver
  in the protocol stack.

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NDIS Drivers

• TDI(Transport Driver Interface) Drivers
• defines a kernel-mode network interface that is
  exposed at the upper edge of transport protocol
  stacks.

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NDIS Drivers

• TDI Client
• kernel-mode driver such as redirector and Server.
• Interface with such transports through TDI
• simplifies the task of developing transport
  drivers in that only the TDI interface needs to
  be coded.
• Transport drivers that expose only the TDI
  interface can be used only by TDI client.

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Network Driver Environments

• Network Driver Environments
• Connectionless drivers
• Connection-oriented drivers
• WAN drivers

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Network Driver Environments

• Connectionless Environment for Network Drivers
• the standard network driver environment for
  connectionless media, such as Ethernet and Token
  Ring.

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Network Driver Environments

• Connection-Oriented Environment for Network
  Drivers
• NDIS supports
• Connection-oriented miniports
• Connection-oriented clients
• Call managers
• Integrated miniport call managers(MCM)

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Network Driver Environments
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Network Driver Environments

• A connection-oriented miniport
• control one or more network interface cards(NIC)
• provides an interface between connection-oriented
  protocols and the NIC hardware
• A call manager
• NDIS protocol that provide call setup and
  tear-down services for connection-oriented
  clients
• An MCM driver
• connection-oriented miniport that also provides
  call manager services to connection-oriented
  clients.

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Network Driver Environments

• Environment for WAN Network Drivers
• Windows 2000 supports wide area network (WAN)
  connections over both connectionless and
  connection-oriented media

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Network Driver Environments
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Network Driver Environments

• Remote Access Service(RAS)
• allows user-mode applications to make dial-up
  connections
• TAPI service provider
• user-mode component that accepts call setup and
  teardown requests from RAS clients and from
  TAPI-aware applications through the SPI
• NDISTAPI
• kernel-mode component that exposes connectionless
  miniports to the TAPI device space.

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Network Driver Environments

• NDPROXY
• a kernel-mode component that exposes
  connection-oriented miniports to the TAPI device
  space.
• NDISWAN
• an intermediate NDIS driver that performs PPP
  protocol/link framing, compression, and
  encryption.
• WAN miniport
• calls many of the same NDIS functions and
  supplies many of the same handlers as does a
  non-WAN NDIS miniport
• Serial driver
• standard device driver for internal serial ports
  or multiport serial cards.

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Network Driver Programming Considerations

• Design Goals for Network drivers written for
  Windows 2000.
• Portability across platforms
• Scalable to multiprocessor systems
• Simple configuration of hardware and software
• Object-based interfaces
• Support for asynchronous I/O

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Reference

• Microsoft Windows 2000 DDK
• Network Driver
• Design guide part 1.