Return-Path: MIME-Version: 1.0 In-Reply-To: References: Date: Wed, 2 Mar 2016 16:18:22 +0200 Message-ID: Subject: Re: Writing an out of the tree new GATT service (for Debian stable): plugin or DBus? From: Luiz Augusto von Dentz To: Olivier Martin Cc: "linux-bluetooth@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Olivier, On Wed, Mar 2, 2016 at 3:20 PM, Olivier Martin wrote: > Hello all, > I am looking at writing a new GATT (server) service for my Linux-based > bluetooth device using Bluez. > My device use Debian stable (Jessie) that uses Bluez v5.23. > Ideally, I would like to build my GATT service out of the Bluez tree. > As far as I understand I have two solutions: > > Solution A) Stay with Bluez v5.23 and write a plugin. I managed to > build `plugins/gatt-example.c` out of the tree. But when `bluetoothd` > loads the plugin, it fails to find the symbol `attrib_db_update`. I am > wondering if it is due to the fact `shared/gatt-server` has not been > added to v5.23 (https://git.kernel.org/cgit/bluetooth/bluez.git/tree/src/shared?h=5.23). > And in this case it would not be possible to have a GATT service out > of the tree for this Bluez version. It depends on the level of control you want to have, if you need extra permissions and low level of access than perhaps building as a plugin is probably a good idea. BlueZ daemon works kind similar to the kernel, the internal API may change so building out of the tree will never be very stable, and you still have to comply to GPL. > Solution B) Moving to the latest Bluez version and use the GATT server > D-BUS API. But it means I need to remove and replace Bluez on my > stable Debian. I understand this solution is the long term solution > but it might take a while before the Linux distributions used this > version of Bluez. If more people like you starting using this features it might become stable faster, thus we encourage people to go with this solution. Btw, you can disable the BlueZ from your distro and just run BlueZ from source without overwriting anything from your distro. > So, is it possible to have an out of the tree plugin with v5.23? I saw > `sixaxis` plugin. But this plugin does not manipulate GATT services > and characteristics. Possible, yes, but it is not recommended, but you can try to create a external plugin that is build within the source tree so that we keep it working as we change the internal APIs. -- Luiz Augusto von Dentz