Re: [PATCH v2] Bluetooth: Fix advertising address type when toggling connectable

[Marcel Holtmann <marcel@holtmann.org>]

Hi Johan,

> When the connectable setting is toggled using mgmt_set_connectable the
> HCI_CONNECTABLE flag will only be set once the related HCI commands
> succeed. When determining what kind of advertising to do we need to
> therefore also check whether there is a pending Set Connectable command
> in addition to the current flag value.
> 
> The enable_advertising function was already taking care of this for the
> advertising type with the help of the get_adv_type function, but was
> failing to do the same for the address type selection. This patch
> converts the get_adv_type function to be more generic in that it returns
> the expected connectable state and updates the enable_advertising
> function to use the return value both for the advertising type as well
> as the advertising address type.
> 
> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
> ---
> net/bluetooth/mgmt.c | 21 +++++++++++----------
> 1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 25b8b278debd..16782b5860c5 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -817,10 +817,9 @@ static void update_class(struct hci_request *req)
> 	hci_req_add(req, HCI_OP_WRITE_CLASS_OF_DEV, sizeof(cod), cod);
> }
> 
> -static u8 get_adv_type(struct hci_dev *hdev)
> +static bool get_connectable(struct hci_dev *hdev)
> {
> 	struct pending_cmd *cmd;
> -	bool connectable;
> 
> 	/* If there's a pending mgmt command the flag will not yet have
> 	 * it's final value, so check for this first.
> @@ -828,12 +827,10 @@ static u8 get_adv_type(struct hci_dev *hdev)
> 	cmd = mgmt_pending_find(MGMT_OP_SET_CONNECTABLE, hdev);
> 	if (cmd) {
> 		struct mgmt_mode *cp = cmd->param;
> -		connectable = !!cp->val;
> -	} else {
> -		connectable = test_bit(HCI_CONNECTABLE, &hdev->dev_flags);
> +		return cp->val;
> 	}
> 
> -	return connectable ? LE_ADV_IND : LE_ADV_NONCONN_IND;
> +	return test_bit(HCI_CONNECTABLE, &hdev->dev_flags);
> }
> 
> static void enable_advertising(struct hci_request *req)
> @@ -841,17 +838,21 @@ static void enable_advertising(struct hci_request *req)
> 	struct hci_dev *hdev = req->hdev;
> 	struct hci_cp_le_set_adv_param cp;
> 	u8 own_addr_type, enable = 0x01;
> -	bool require_privacy;
> +	bool connectable;
> 
> -	require_privacy = !test_bit(HCI_CONNECTABLE, &hdev->dev_flags);
> +	connectable = get_connectable(hdev);
> 
> -	if (hci_update_random_address(req, require_privacy, &own_addr_type) < 0)
> +	/* If we're connectable set require_privacy to false as we
> +	 * shouldn't use NRPAs in that case. If we're non-connectable
> +	 * however we can allow NRPAs to be used.
> +	 */
> +	if (hci_update_random_address(req, !connectable, &own_addr_type) < 0)
> 		return;

I really do not want to be pedantic, but this comment is misleading. It is a bit hard to understand. Also I am not sure if it NRPA or URPA. I think using an acronym here is confusing.

	/* Set require_privacy to true only when non-connectable advertising
	 * is used. In that case it is fine to use an unresolvable private
	 * address.
	 */ 

Regards

Marcel