Handling PnP Events and Power Management Events in a Protocol Driver

When the operating system issues a Plug and Play (PnP) I/O request packet (IRP) or a power management IRP to a target device object that represents a network interface card (NIC), NDIS intercepts the IRP. NDIS indicates the event to each bound protocol driver and each bound intermediate driver by calling the driver's ProtocolNetPnPEvent function. In the call to ProtocolNetPnPEvent, NDIS passes a pointer to a NET_PNP_EVENT_NOTIFICATION that contains a NET_PNP_EVENT structure. The NET_PNP_EVENT structure describes the PnP event or power management event being indicated. For more information about the protocol driver PnP interface, see Handling PnP Event Notifications in a Protocol Driver.

The following list contains PnP and power management events, as indicated by the NetEvent code in the NET_PNP_EVENT structure:

• NetEventSetPower

  Indicates a Set Power request, which specifies that the miniport adapter should transition to a particular power state. A power management–aware protocol driver should always succeed this event by returning NDIS_STATUS_SUCCESS. An old protocol driver can return NDIS_STATUS_NOT_SUPPORTED to indicate that NDIS should unbind it from the miniport adapter.

  After issuing the set power request, NDIS pauses the driver stack if the miniport adapter is transitioning to a low-power state. NDIS restarts the driver stack before the set-power request if the miniport adapter is transitioning to the working state (D0). For more information about pausing and restarting the driver stack, see Pausing a Driver Stack.

  If the miniport adapter is in a low-power state, the protocol driver cannot issue any OID requests. This requirement is an additional power management restriction that is added to the other restrictions that apply when the driver stack is in the Paused state.

  If the underlying miniport adapter is not power management–aware, the miniport driver sets the PowerManagementCapabilities member of NDIS_MINIPORT_ADAPTER_GENERAL_ATTRIBUTES to NULL and NDIS sets the PowerManagementCapabilities member of NDIS_BIND_PARAMETERS to NULL.

  Note Starting with NDIS 6.30, after being notified of this event, the protocol driver must stop generating new I/O requests and should not wait for the completion of any pending I/O requests within the context of the call to ProtocolNetPnPEvent.

  For more information about set-power events, see Handling PnP Events and Power Management Events in an Intermediate Driver.

• NetEventQueryPower

  Indicates a Query Power request, which queries whether the underlying miniport adapter can make a transition to a particular power state. A protocol driver should always succeed a NetEventQueryPower . After establishing an active connection, a protocol driver can call PoRegisterSystemState to register a continuous busy state. As long as the state registration is in effect, the power manager does not attempt to put the system to sleep. After the connection becomes inactive, the protocol driver cancels the state registration by calling PoUnregisterSystemState. A protocol driver should never try to prevent the system from transitioning to the sleeping state by failing a NetEventQueryRemoveDevice. Note that a NetEventQueryPower is always followed by a NetEventSetPower. A NetEventSetPower that sets the device's current power state in effect cancels the NetEventQueryPower.

  Note Starting with NDIS 6.30, after being notified of this event, the protocol driver should not wait for the completion of any pending I/O requests within the context of the call to ProtocolNetPnPEvent.

• NetEventQueryRemoveDevice

  Indicates a Query Remove Device request, which queries whether the NIC can be removed without disrupting operations. If a protocol driver cannot release a device (for example, because the device is in use), it must fail a NetEventQueryRemoveDevice by returning NDIS_STATUS_FAILURE.

• NetEventCancelRemoveDevice

  Indicates a Cancel Remove Device request, which cancels the removal of an underlying NIC. The protocol driver should always succeed this event by returning NDIS_STATUS_SUCCESS.

• NetEventReconfigure

  Indicates that the configuration has changed for a network component. For example, if a user changes the IP address for TCP/IP, NDIS indicates this event to the TCP/IP protocol with the NetEventReconfigure code. The protocol driver can, in rare circumstances, return a failure code if it is not able to apply the indicated configuration changes and there are no available default values. A failed attempt to allocate memory is an example of a case in which the protocol returns a failure code. Returning an error code can result in prompting the user to restart the system.

  A protocol should validate NetEventReconfigure-related data passed to its ProtocolNetPnPEvent function. For more information about such data, see NET_PNP_EVENT for Protocol Drivers.

• NetEventBindList

  Indicates to a protocol driver that its bind list processing order has been reconfigured. This list indicates a relative order to be applied to the protocol's bindings when processing, for example, a user request that might be routed to one of several bindings. The buffer passed with this event contains a list of device names formatted as NULL-terminated Unicode strings. The format of each device name is identical to the DeviceName parameter that is passed to a call to ProtocolBindAdapterEx.

  A protocol should validate NetEventBindList-related data passed to its ProtocolNetPnPEvent function. For more information about such data, see NET_PNP_EVENT for Protocol Drivers.

  A protocol should validate NetEventBindList-related data passed to its ProtocolNetPnPEvent function. For more information about such data, see NET_PNP_EVENT for Protocol Drivers.

• NetEventBindsComplete

  Indicates that a protocol driver has bound to all the NICs to which it can bind. NDIS will not indicate any more bindings to the protocol driver unless, for example, a PnP NIC is plugged into the system.

• NetEventPnPCapabilities

  Indicates that the user enabled or disabled the wake-up capabilities of the underlying adapter. (The ProtocolBindingContext parameter that NDIS passes to ProtocolNetPnPEvent specifies the binding .)

• NetEventPause

  Indicates that the specified protocol binding should enter thePausing state. The binding will enter the Paused state after NDIS has completed all of the outstanding send requests for the binding. For more information about pausing a binding, see Pausing a Binding.

• NetEventRestart

  Indicates that the specified protocol binding has entered the Restarting state. After the protocol driver is ready to resume send and receive operations for the binding, the binding enters the Running state. For more information about restarting a binding, see Restarting a Binding.

• NetEventPortActivation

  Indicates the activation of a list of ports that are associated with the specified binding. For more information about pausing a binding, see Handling the Port Activation PnP Event.

• NetEventPortDeactivation

  Indicates the deactivation of a list of ports that are associated with the specified binding. For more information about pausing a binding, see Handling the Port Deactivation PnP Event.

• NetEventIMReEnableDevice

  Indicates that the configuration has changed for a virtual miniport of an NDIS 6.0 or later intermediate driver. NetEventIMReEnableDevice is similar to the NetEventReconfigure event except that the intermediate driver receives this event for a single virtual miniport and the NetEventReconfigure event applies to all of the intermediate driver's virtual miniports. For example, an intermediate driver receives the NetEventIMReEnableDevice event when a user disables and then enables a single virtual miniport from the Device Manager or another source. For examples of intermediate driver power management, see the NDIS MUX Intermediate Driver and Notify Object driver sample available in the Windows driver samples repository on GitHub.

The Buffer member of the NET_PNP_EVENT structure points to a buffer that contains information specific to the event being indicated.

A protocol driver can complete the call to ProtocolNetPnPEvent asynchronously with NdisCompleteNetPnPEvent.