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802.11 WLAN Adapter Removal

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When a wireless LAN (WLAN) adapter is removed or disabled, the operating system calls Dot11ExtIhvDeinitAdapter to notify the IHV Extensions DLL of the adapter's removal. The operating system also calls the Dot11ExtIhvDeinitAdapter function for every adapter managed by the IHV Extensions DLL before the operating system unloads the DLL.

When Dot11ExtIhvDeinitAdapter is called, the IHV Extensions DLL must follow these guidelines.

  • The IHV Extensions DLL must free any allocated resources for the WLAN adapter. In particular, all memory allocated through calls to Dot11ExtAllocateBuffer must be freed through calls to Dot11ExtFreeBuffer.

  • The handle used by the operating system to reference the WLAN adapter is no longer valid when Dot11ExtIhvDeinitAdapter is called. The operating system passes its handle to the IHV Extensions DLL through the hDot11SvcHandle parameter when Dot11ExtIhvInitAdapter is called.

    Within the call to the Dot11ExtIhvDeinitAdapter function and after returning from the call, the DLL must not use the handle value when calling any IHV Extensibility function that declares an hDot11SvcHandle parameter, such as Dot11ExtSendPacket.

  • If the IHV Extensions DLL had a pending pre-association operation, which was initiated through a call to the Dot11ExtIhvPerformPreAssociate IHV Handler function, the operating system regards the operation as canceled through the call to the Dot11ExtIhvDeinitAdapter function. Within the call, the DLL must cancel the pre-association operation internally but must not call Dot11ExtPreAssociateCompletion to complete the pre-association operation.

    For more information about the pre-association operation, see Pre-Association Operations.

  • If the IHV Extensions DLL had a pending post-association operation, which was initiated through a call to the Dot11ExtIhvPerformPostAssociate IHV Handler function, the operating system cancels the operation by calling the Dot11ExtIhvStopPostAssociate function before it calls Dot11ExtIhvDeinitAdapter.

    For more information about the post-association operation, see Post-Association Operations.

  • The operating system calls the Dot11ExtIhvDeinitAdapter function for every adapter managed by the IHV Extensions DLL before the operating system unloads the DLL. In this situation, the operating system calls the Dot11ExtIhvDeinitService IHV Handler function after the last WLAN adapter has been halted through a call to Dot11ExtIhvDeinitAdapter.

    For more information about this operation, see DLL Stop Operations.