Return-Path: MIME-Version: 1.0 In-Reply-To: References: <1302892422-32206-1-git-send-email-claudio.takahasi@openbossa.org> <20110415184728.GA2359@joana> <1302915790.2503.31.camel@aeonflux> <20110416070006.GA10860@jh-x301> Date: Mon, 30 May 2011 20:27:22 +0300 Message-ID: Subject: Re: [RFC] Proposal to distinguish address device types From: Luiz Augusto von Dentz To: Claudio Takahasi Cc: Marcel Holtmann , Johan Hedberg , "Gustavo F. Padovan" , linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 List-ID: Hi, On Mon, Apr 18, 2011 at 9:20 PM, Claudio Takahasi wrote: > Hi Marcel/Johan/Gustavo, > > On Sat, Apr 16, 2011 at 5:04 PM, Claudio Takahasi > wrote: >> Hi Marcel, >> >> On Sat, Apr 16, 2011 at 7:00 AM, Johan Hedberg = wrote: >>> Hi Marcel, >>> >>> On Fri, Apr 15, 2011, Marcel Holtmann wrote: >>>> > > + BDADDR_TYPE_LE_PUBLIC, >>>> > > + BRADDR_TYPE_LE_RANDOM >>>> > > +}; >>>> >>>> I am also not sure the we should have this BR/EDR differentiation sinc= e >>>> the specification only talks about public and random addresses. And we >>>> should follow the specification type value here. I am against >>>> introducing our enum here. >>> >>> The HCI specification only has values for public and random because >>> everywhere they are used it is already clear from the context (the HCI >>> command or event in question) if we're talking about LE or BR/EDR. We o= n >>> the other hand don't have this contextual information with the >>> mgmt_pair_device command. Saying "public" there could mean both BR/EDR >>> public or LE public, i.e. an enum with just two possible values is not >>> going to be of much use to us. Because of this difference between our >>> API and that of HCI I don't think it's fair to apply the HCI >>> convention/restriction to us. >>> >>> Johan >>> >> >> I added 3 values because it gives more flexibility. Possible use cases: >> - Whitelist needs the address type >> - SMP >> - As input to decide to store or not information about the device >> since private address can change every 15minutes >> >> =A0At the moment we only need to know if the address is basic rate or LE >> to select the discovery type: SDP or LE Discovery primary. For >> pairing, Vinicius is using the kernel advertising cache to discover >> the address type, passing the address type could avoid wrong fallback >> to basic rate if the entry is not found in the cache. >> >> Claudio >> > > Any objection to add the address type in the MGMT_EV_DEVICE_CONNECTED eve= nt? > Inside event.c there are a lot of get_adapter_and_device calls, for > some contexts it creates a new device object if it doesn't exist(eg: > incoming pairing). But the type is required to create a new device, > otherwise it will not be possible to trigger the reverse service > search. Obtain the type later based on the link key type will not > work, unless we create a device with unknown type to be able to call > the agent methods. > > BTW, is there a reason why it is necessary to "force" device > creation(get_adapter_and_device option)? In my opinion we could create > the device(if it doesn't exist) it inside btd_event_conn_complete > only. There is a potential race condition: other application calling > RemoveDevice, but for this case reference counting should work. > > Currently, controllers doesn't support simultaneous BR/EDR/LE, this is > another argument to export the address type or connection type through > management interface avoiding future changes on the API. What about having a different socket family for le e.g. AF_BLUETOOTH_LE? With that we could have more direct mapping with the spec, with proper 49 bit addresses and things like that so we don't have to break existing code. --=20 Luiz Augusto von Dentz Computer Engineer