Hi, On Saturday, 15 October 2016 00:43:13 CEST wujiangbo wrote: > On Fri, Oct 14, 2016 at 05:19:38PM +0300, Johan Hedberg wrote: > > Hi Jiangbo, > > > > Please don't top-post on this list. > > > > On Fri, Oct 14, 2016, Wu, Jiangbo wrote: > > > If pair a device that unpair firstly that remove encryption key, > > > encryption key event will be emitted. kernel will receive > > > 'L2CAP_CID_SMP_BREDR' frame, and then it will use SMP to distribute > > > key. SMP would like to use LTK, IRK and CRSK to notify user. If it > > > don't identify device by which conn type they are, only marks LE as > > > the device type, > > > > Why would that happen? Before SMP over BR/EDR happens pairing would have > > happened over BR/EDR, so bluetoothd should know that BR/EDR is supported > > as well (it would even be aware of an existing BR/EDR connection). Are > > you perhaps trying to work around some bluetoothd bug with all this? > > I use upstream bluez source code without change. > > Yes, bluetoothd scan will find device type is BR/EDR or LE. As my case, > device is BR/EDR. But if kernel report CRSK notify, bluetoothd will change > the device type to LE. The code you can see: > new_csrk_callback -> btd_adapter_get_device -> btd_adapter_find_device > if (bdaddr_type == BDADDR_BREDR) > device_set_bredr_support(device); > else > device_set_le_support(device, bdaddr_type); > As Marcel mentioned before, LTK, IRK and CRSK are only valid for LE link. > So the rootcause is why remote start to pair a BR/EDR device, the kernel > will receive CRSK event. > > This is the first pair, and it will pair success even if receive CRSK > notify. And the second and the next all pair will be failed with remote > device unpair and then pair again. > > > > while Bluetoothd will use this 'addr' and 'addr type' to reply the > > > comfirm to kernel. > > > > What reply are you talking about? There's no user interaction involved > > with SMP over BR/EDR - that would already have occurred when SSP over > > BR/EDR happened. > > Sorry to confuse the case, the pairing failed coming with next pair > procedure. Because at the last pair with CRSK notify, device type will be > changed to LE, following is the failed scenario after last success with > CRSK notify. Remote unpair and pair again. > > This reply is SPP, user confirm passkey reply. When pairing proceduce, User > confirm the pairing request through bluetoothd, that will send mgmt op > 'MGMT_OP_USER_CONFIRM_REPLY' with device address and device type in > mgmt_cp_user_confirm_reply. Kernel use the device address and type to lookup > hci conn. Unfortunately, it will lookup hci_conn from LE hashtable, that > don't include hci conn. So spp reply couldn't send to remote, caused pair > failed. > > > At the same time kernel always uses them to lookup hci_conn in LE > > > hashtable firstly, because addr type always marks as LE. Obviously it > > > will failed with SMP over BR/EDR. > > > > I don't follow this either since there shouldn't have been any "reply" > > from user space for SMP over BR/EDR. All there should be are events from > > the kernel for the generated LE keys. > > > > > Actually, SPM is only for LE in SPEC, > > > > That's not true. SMP is specified both for LE-U and ACL-U. > > > > > but kernel already support and use SMP over BR/EDR. if BR/EDR > > > exchanges key with SMP, it will never reply pairing response to > > > remote, in other words it will be never paired, that is happened in > > > our products. > > > > Szymon recently implemented SMP over BR/EDR for Zephyr and used > > Linux/BlueZ as a reference for testing. He didn't report any issues like > > this. It might help if you could provide some logs (particularly > > HCI/btmon but also from bluetoothd) to understand what's the actual > > issue you're seeing. > > > > Johan > > Sorry to confuse this issue, the log is not in my hand right now, > so it maybe later. So I was able to reproduce this issue. This is bluetoothd bug and not kernel one. This bug is no specific to cross-transport pairing. It can happen with any dual-mode device that is doing BR/EDR pairing while being known as dual mode by bluetoothd when agent replies with passkey or confirmation. To fix this we probably need to hold extra information in 'struct authentication_req' in device.c about type of pairing (LE or BR/EDR). This is not a one-liner-fix so I don't have a patch ready yet. -- pozdrawiam Szymon Janc -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
