IEEE EtherType Handling
The IHV Extensions DLL can specify a list of IEEE EtherTypes for special handling of packets received by the wireless LAN (WLAN) adapter. The following types of EtherType handling can be specified.
The IHV Extensions DLL can specify packet decryption exemptions for received packets. For example, the DLL can specify that a packet with a specified EtherType is allowed to be received unencrypted even if a matching cipher key is configured on the WLAN adapter.
The IHV Extensions DLL can register the EtherTypes that it will process and consume. The operating system forwards packets that match a registered EtherType to the DLL through calls to the Dot11ExtIhvReceivePacket function.
The IHV Extensions DLL specifies EtherType handling through a call to the Dot11ExtSetEtherTypeHandling function. When calling this function, the IHV Extensions DLL must follow these guidelines.
The IHV Extensions DLL specifies its list of privacy exemptions through an array of zero or more DOT11_PRIVACY_EXEMPTION structures. If the IHV Extensions DLL does not call Dot11ExtSetEtherTypeHandling, the operating system defaults to an empty list of privacy exemptions for any 802.11 association with an access point (AP). Note For Windows Vista, the IHV Extensions DLL supports only infrastructure basic service set (BSS) networks.
The IHV Extensions DLL registers a list of zero or more EtherTypes that it will receive. Typically, the DLL registers the EtherTypes for the security packets it processes during the post-association operation. For more information about this operation, see Post-Association Operations.
If the IHV Extensions DLL does not call Dot11ExtSetEtherTypeHandling, the operating system defaults to an empty list of registered EtherTypes for any 802.11 association with an AP.
After the IHV Extensions DLL completes the pre-association operation by calling Dot11ExtPreAssociateCompletion, the list of privacy exemptions and EtherType registrations specified through a call to Dot11ExtSetEtherTypeHandling is applied to every 802.11 association made by the WLAN adapter while connected to the basic service set (BSS) network.
The operating system clears the list of privacy exemptions and EtherType registrations before it calls Dot11ExtIhvAdapterReset.