Return-Path: Date: Wed, 20 Jul 2016 10:39:44 +0300 From: Johan Hedberg To: Alexander Aring Cc: Luiz Augusto von Dentz , linux-wpan@vger.kernel.org, kernel@pengutronix.de, kaspar@schleiser.de, Jukka Rissanen , "linux-bluetooth@vger.kernel.org" , Patrik Flykt , carlesgo@entel.upc.edu Subject: Re: [RFC bluetooth-next 20/20] 6lowpan: bluetooth: add new implementation Message-ID: <20160720073944.GA20780@t440s> References: <20160711195044.25343-1-aar@pengutronix.de> <20160711195044.25343-21-aar@pengutronix.de> <11469f72-fa15-5545-387c-ecd051b74897@pengutronix.de> <190983bc-9467-8ff8-436c-ca1fcdfe001b@pengutronix.de> <20160719054501.GA17979@t440s.P-661HNU-F1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-wpan-owner@vger.kernel.org List-ID: Hi Alex, On Tue, Jul 19, 2016, Alexander Aring wrote: > mhhh, I am not a bluetooth expert. What really means "periodically > change is RPA" and how is this done in the Linux bluetooth? > > When "changing the RPA" happens, does that mean the all connections will > be lost (unregister interface). Then the previous connections will be > recreated (register interface) with a complete different MAC address? Connections aren't lost when the random address is changed. That's why we track the hci_conn->init_addr and hci_conn->resp_addr. The way this is dealt with e.g. the Security Manager protocol is that the connection creation address *is* the address for the remote device throughout the entire connection, no matter what happens to the local and remote random address during the connection. I would expect 6LoWPAN do do something similar. What was still unclear to me (maybe I missed it in the thread): does the 6LoWPAN for LE spec require using the connection creation address or the identity address? If it would be the latter then that's something that will never change and the whole interface recreation issue goes away. Johan