Hi Chaojie, >> > + pdu_len += BT_ATT_SIGNATURE_LEN; >> > + att = op->user_data; >> >> I don't think that this code here works. op->user_data refers to user data provided in >> bt_att_send and not the bt_att structure. Instead, I would just add a "struct bt_att >> *att" field to struct att_send_op and remove the local variable "att". > > In my implementation , op->user_data in the signed write command code path refer to > the bt_att structure because struct bt_att provided in bt_att_send parameter user_data. > So it could be work. What would happen to the user passed user_data then? :) > But your proposal make more sense if extend the att_send_op struct to store struct bt_att *att > Because user_data should be provided for callback , current implementation style is ugly indeed. > Yep, sounds better. > This point is my major purpose for this patch discussion. We can see in android/gatt.c, > Csrk and sign counter get from struct device in new_csrk_callback by mgmt_register > event from kernel. And we can get att->csrk from struct device. However, in > btgatt-client tool, there is no struct device and no event notification handler. > So if we have to implemetnt bt_att_set_csrk, how can we get csrk ? We want a generic way to obtain the CSRK and the sign count. Eventually bluetoothd will do exactly that where src/device.c (which will own a struct bt_gatt_client instance) will give us the CSRK and initialize the sign count. For testing purposes you're welcome to add this functionality to tools/btgatt-client by directly hooking into shared/mgmt. > And for the lifecycle of sign_counter, it should be updated to store in files after signed write. > Btgatt-client need to create special file to do that? This is a good question. I think as far as btgatt-client is concerned, I wouldn't worry about persisting the sign count. btgatt-client is meant to be a simple tool and not maintain state the way the daemon does. So, keep it simple there. Maybe somehow reset the count to 0 every time btgatt-client restarts? Cheers, Arman -- 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
