DOT11_EXTSTA_RECV_CONTEXT structure

Description

Important The Native 802.11 Wireless LAN interface is deprecated in Windows 10 and later. Please use the WLAN Device Driver Interface (WDI) instead. For more information about WDI, see WLAN Universal Windows driver model.

The DOT11_EXTSTA_RECV_CONTEXT structure defines the Native 802.11 attributes of a received packet by the 802.11 station and indicated by the miniport driver operating in either Extensible Station (ExtSTA) or Network Monitor (NetMon) modes. For more information about these operation modes, see Native 802.11 Operation Modes.

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

This member must be set to DOT11_EXTSTA_RECV_CONTEXT_REVISION_1.

Size

This member must be set to sizeof(DOT11_EXTSTA_RECV_CONTEXT).

For more information about these members, see NDIS_OBJECT_HEADER.

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 setting DOT11_RECV_FLAG_RAW_PACKET_FCS_FAILURE.

DOT11_RECV_FLAG_RAW_PACKET_TIMESTAMP

If this bit is set, the NIC sets the timestamp information in the ullTimestamp member.

uPhyId

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 currently reserved for future use and must contain zero.

pvMediaSpecificInfo

A pointer to a buffer that contains media-specific information. The miniport 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 when the packet was received. This member is provided to support indicating raw 802.11 packets.

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

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;

Remarks

When performing 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 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 preparing 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.

For more information about raw packets, see Indicating Raw 802.11 Packets.

For more information about Native 802.11 receive operations, see Native 802.11 Receive Operations.

See also

NdisMIndicateReceiveNetBufferLists

NET_BUFFER_LIST

NET_BUFFER

NET_BUFFER_LIST_INFO

OID_DOT11_DATA_RATE_MAPPING_TABLE

NDIS_OBJECT_HEADER