_BRB_L2CA_UPDATE_CHANNEL structure (bthddi.h)
The _BRB_L2CA_UPDATE_CHANNEL structure describes an update to the link characteristics of an open L2CAP channel to a remote device or to ascertain when certain channel attributes have changed.
Syntax
struct _BRB_L2CA_UPDATE_CHANNEL {
BRB_HEADER Hdr;
BTH_ADDR BtAddress;
L2CAP_CHANNEL_HANDLE ChannelHandle;
ULONG NewChannelFlags;
ULONG FailedChannelFlags;
};
Members
Hdr
A BRB_HEADER structure that contains information about the current BRB.
BtAddress
The Bluetooth address of the remote device.
ChannelHandle
The L2CAP channel handle that was returned by Bluetooth driver stack in response to an earlier BRB_L2CA_OPEN_CHANNEL or BRB_L2CA_OPEN_CHANNEL_RESPONSE request.
NewChannelFlags
A combination of flag values that specify the updated requirements for the channel. This member should be set to CF_ROLE_EITHER.
FailedChannelFlags
The flag or flags in the NewChannelFlags member that the Bluetooth driver stack was not able to honor. This member contains information only if the BRB call failed.
Remarks
To retrieve the current settings of a L2CAP channel, profile drivers should build and send a BRB_L2CA_UPDATE_CHANNEL request.
The profile driver can then determine when certain channel attributes have changed. Additionally, if the CF_LINK_PASSIVE_MODE flag is not set, the BRB will attempt to change the current channel settings to the remote device.
The primary use of BRB_L2CA_UPDATE_CHANNEL is to determine when authentication or encryption has been enabled for a connection.
In some cases, L2CAP connections can be established without the profile driver specifying that authentication is required, but authentication will happen automatically due to choices made by the user. In this case, a period of time passes between when the connection is established and when authentication and encryption begin working. Calls to BRB_L2CA_UPDATE_CHANNEL are blocked until authentication and encryption are complete.
By building and sending a BRB_L2CA_UPDATE_CHANNEL request, profile drivers can avoid using the connection prior to authentication.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Versions:_Supported in Windows Vista, and later. |
| Header | bthddi.h (include Bthddi.h) |