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DOT11_EXTSTA_RECV_CONTEXT (Compact 7)

  • Article

3/12/2014

This structure defines the Native 802.11 attributes of a packet that is received by the 802.11 station and that is indicated by the miniport driver that is operating in either Extensible Station (ExtSTA) or Network Monitor (NetMon) modes.

Syntax

typedef struct DOT11_EXTSTA_RECV_CONTEXT {
  NDIS_OBJECT_HEADER  Header;
  ULONG  uReceiveFlags;
  ULONG  uPhyId;
  ULONG  uChCenterFrequency;
  USHORT  usNumberOfMPDUsReceived;
  LONG  lRSSI;
  UCHAR  ucDataRate;
  ULONG  uSizeMediaSpecificInfo;
  PVOID  pvMediaSpecificInfo;
  ULONGLONG  ullTimestamp;
} DOT11_EXTSTA_RECV_CONTEXT, *PDOT11_EXTSTA_RECV_CONTEXT;

Members

  • Header
    The type, revision, and size of the DOT11_EXTSTA_RECV_CONTEXT structure. This member is formatted as an NDIS_OBJECT_HEADER structure.

    The miniport driver must set the members of Header to the following values:

    Type

    This member must be set to NDIS_OBJECT_TYPE_DEFAULT

    Revision

    DOT11_EXTSTA_RECV_CONTEXT_REVISION_1

    Size

    This member must be set to sizeof(DOT11_EXTSTA_RECV_CONTEXT)

  • uReceiveFlags
    The attributes of the received packet data specified through a bitmask.

    If the miniport driver is operating in ExtSTA mode, the driver must always set uReceiveFlags to zero.

    The following flag values are valid for the miniport driver if is operating in NetMon mode.

    DOT11_RECV_FLAG_RAW_PACKET

    If this bit is set, the packet contains the data as it was originally received by the 802.11 station. For more information about raw packets, see Indicating Raw 802.11 Packets.

    DOT11_RECV_FLAG_RAW_PACKET_FCS_FAILURE

    If this bit is set, the raw packet data was received with frame check sequence (FCS) failures.

    Note

    The miniport driver must set DOT11_RECV_FLAG_RAW_PACKET when it sets DOT11_RECV_FLAG_RAW_PACKET_FCS_FAILURE.

    DOT11_RECV_FLAG_RAW_PACKET_TIMESTAMP

    If this bit is set, the network adapter sets the time stamp information in the ullTimestamp member.

  • uPhID
    The identifier (ID) of the PHY on which the 802.11 station received the packet
  • uChCenterFrequency
    The channel center frequency, in units of megahertz (MHz), of the frequency band on which the 802.11 station received the packet
  • usNumberOfMPDUsReceived
    The number of media access control (MAC) protocol data unit (MPDU) fragments received and reassembled by the 802.11 station for the packet. The value of usNumberOfMPDUsReceived must be from one through the value of DOT11_MAX_NUM_OF_FRAGMENTS.
  • lRSSI
    The received signal strength indication (RSSI) value for the last received MPDU fragment of the 802.11 packet. The RSSI value is in units of decibels referenced to 1.0 milliwatts (dBm).
  • ucDataRate
    The data rate at which the 802.11 station received the packet. The value of ucDataRate is the value of the ucDataRateIndex member of the data rate from the 802.11 station’s data rate mapping table. For more information about the data rate mapping table, see OID_DOT11_DATA_RATE_MAPPING_TABLE.

  • uSizeMediaSpecificInfo
    The size, in bytes, of the media specific information at the pvMediaSpecificInfo member. uSizeMediaSpecificInfo supports copying of the media-specific information and passing it to an IHV extension.

    Note

    This member is reserved; set to 0 (zero).

  • pvMediaSpecificInfo
    A pointer to a buffer that contains media-specific information. The mininiport driver can set this member if the miniport driver passes media-specific OOB data to an IHV-specific 802.3 protocol driver.

    The native 802.11 framework copies this pointer to the MediaSpecificInformation entry at the NetBufferListInfo member of the 802.3 NET_BUFFER_LIST structures in NDIS receive indications.

    Note

    IHV extensions are currently unable to receive the MediaSpecificInformation.

  • ullTimestamp
    An 802.11 timing synchronization function (TSF) timer value, in microseconds, that specifies the time that the packet was received. This member is provided to support indicating raw 802.11 packets.

    If a network adapter does not support ullTimestamp, it must not set the DOT11_RECV_FLAG_RAW_PACKET_TIMESTAMP flag in the uReceiveFlags member.

Remarks

When it performs a Native 802.11 receive operation, the miniport driver must format each received 802.11 packet as a NET_BUFFER_LIST structure, with the packet data formatted as a NET_BUFFER structure and linked to the NET_BUFFER_LIST structure. Each NET_BUFFER_LIST structure must include out-of-band (OOB) data. The OOB data specifies the attributes of the received packet that are specific to the wireless LAN (WLAN) media.

The miniport driver accesses the Native 802.11 OOB data through the NET_BUFFER_LIST_INFO macro with the following parameters:

  • The _NBL parameter, which is passed the pointer to the NET_BUFFER_LIST structure that is used for the received 802.11 packet
  • The _Id parameter, which is passed the identifier (ID) value of MediaSpecificInformation

If the miniport driver sets DOT11_RECV_FLAG_RAW_PACKET in the uReceiveFlags member, the driver must follow these guidelines when it prepares the DOT11_EXTSTA_RECV_CONTEXT structure:

  • Set the value of usNumberOfMPDUsReceived to one
  • Set the value of lRSSI to the RSSI value for the raw packet itself
  • Set the value of ucDataRate to the ucDataRateIndex value for the raw packet itself
  • Set the value of ucRSSI to the normalized RSSI value for the raw packet itself

Requirements

Header

windot11.h

See Also

Reference

Native 802.11 Data Types
NDIS_OBJECT_HEADER
OID_DOT11_DATA_RATE_MAPPING_TABLE
NET_BUFFER
NET_BUFFER_LIST_INFO
Native 802.11 Wireless LAN Reference