Bluetooth: Provide function to create and set connection parameters

In some cases it is useful to not overwrite connection parametes and
instead just create default ones if they don't exist. This function
does exactly that. hci_conn_params_add will allow to create new
default connection parameters. hci_conn_params_set will set the
values and also create new parameters if they don't exist.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci_core.h

@@ -852,7 +852,8 @@ int hci_white_list_del(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 
 struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev,
 					       bdaddr_t *addr, u8 addr_type);
-int hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
+int hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
+int hci_conn_params_set(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 			u8 auto_connect, u16 conn_min_interval,
 			u16 conn_max_interval);
 void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);

net/bluetooth/hci_core.c

@@ -3472,7 +3472,41 @@ void hci_pend_le_conns_clear(struct hci_dev *hdev)
 }
 
 /* This function requires the caller holds hdev->lock */
-int hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
+int hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
+{
+	struct hci_conn_params *params;
+
+	if (!is_identity_address(addr, addr_type))
+		return -EINVAL;
+
+	params = hci_conn_params_lookup(hdev, addr, addr_type);
+	if (params)
+		return 0;
+
+	params = kzalloc(sizeof(*params), GFP_KERNEL);
+	if (!params) {
+		BT_ERR("Out of memory");
+		return -ENOMEM;
+	}
+
+	bacpy(&params->addr, addr);
+	params->addr_type = addr_type;
+
+	list_add(&params->list, &hdev->le_conn_params);
+
+	params->conn_min_interval = hdev->le_conn_min_interval;
+	params->conn_max_interval = hdev->le_conn_max_interval;
+	params->conn_latency = hdev->le_conn_latency;
+	params->supervision_timeout = hdev->le_supv_timeout;
+	params->auto_connect = HCI_AUTO_CONN_DISABLED;
+
+	BT_DBG("addr %pMR (type %u)", addr, addr_type);
+
+	return 0;
+}
+
+/* This function requires the caller holds hdev->lock */
+int hci_conn_params_set(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 			u8 auto_connect, u16 conn_min_interval,
 			u16 conn_max_interval)
 {

net/bluetooth/mgmt.c

@@ -5014,7 +5014,10 @@ static int add_device(struct sock *sk, struct hci_dev *hdev,
 	else
 		auto_conn = HCI_AUTO_CONN_DISABLED;
 
-	if (hci_conn_params_add(hdev, &cp->addr.bdaddr, addr_type, auto_conn,
+	/* If the connection parameters don't exist for this device,
+	 * they will be created and configured with defaults.
+	 */
+	if (hci_conn_params_set(hdev, &cp->addr.bdaddr, addr_type, auto_conn,
 				hdev->le_conn_min_interval,
 				hdev->le_conn_max_interval) < 0) {
 		err = cmd_complete(sk, hdev->id, MGMT_OP_ADD_DEVICE,