HAM_Return_Port_Info (Function 0x0C)
Mandatory function for Fibre Channel drivers. Allows NWPA to discover switch port information in the path to the device.
The HAM must return a handle in the 4-byte buffer pointed at by the HACB's vDataBufferPtr field to identify a unique, persistent port value. This port handle identifies the I/O path to the active device and facilitates multi-path failover.