L2CAP Extended Features on 2.6.36
On October 20th, Linus released the 2.6.36 kernel and one of the new features released with it was the support in the Linux Bluetooth stack
for the L2CAP Extended Features. Also called eL2CAP, the L2CAP Extended Features add some new features to the L2CAP layer, like the Enhanced
Retransmission Mode(ERTM), a reliable protocol with error and flow control; the Streaming Mode, an unreliable protocol for streaming purpouses; the
Frame Check Sequence, a checksum for each received packet; and Segmentation and Reassembly of L2CAP packets which make retransmission
easier. The L2CAP Extended Features were in the kernel before, but in an experimental mode and disabled by default.
Other Bluetooth changes in 2.6.36: In-kernel blacklist for incoming connections, that allow dropping selected incoming connections in
kernel space without having to wake up bluetoothd. Support for the Atheros AR300x chip. A new hci_recv_stream_fragment() function which is part of
a refactory in the HCI recv path to make the life of some drivers easier.