Bluetooth: hci_sync: Set Privacy Mode when updating the resolving list

This adds support for Set Privacy Mode when updating the resolving list
when HCI_CONN_FLAG_DEVICE_PRIVACY so the controller shall use Device
Mode for devices programmed in the resolving list, Device Mode is
actually required when the remote device are not able to use RPA as
otherwise the default mode is Network Privacy Mode in which only
allows RPAs thus the controller would filter out advertisement using
identity addresses for which there is an IRK.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci.h

@@ -1940,6 +1940,16 @@ struct hci_rp_le_read_transmit_power {
 	__s8  max_le_tx_power;
 } __packed;
 
+#define HCI_NETWORK_PRIVACY		0x00
+#define HCI_DEVICE_PRIVACY		0x01
+
+#define HCI_OP_LE_SET_PRIVACY_MODE	0x204e
+struct hci_cp_le_set_privacy_mode {
+	__u8  bdaddr_type;
+	bdaddr_t  bdaddr;
+	__u8  mode;
+} __packed;
+
 #define HCI_OP_LE_READ_BUFFER_SIZE_V2	0x2060
 struct hci_rp_le_read_buffer_size_v2 {
 	__u8    status;

include/net/bluetooth/hci_core.h

@@ -757,6 +757,7 @@ struct hci_conn_params {
 	struct hci_conn *conn;
 	bool explicit_connect;
 	DECLARE_BITMAP(flags, __HCI_CONN_NUM_FLAGS);
+	u8  privacy_mode;
 };
 
 extern struct list_head hci_dev_list;

net/bluetooth/hci_event.c

@@ -1489,6 +1489,33 @@ static u8 hci_cc_le_read_transmit_power(struct hci_dev *hdev, void *data,
 	return rp->status;
 }
 
+static u8 hci_cc_le_set_privacy_mode(struct hci_dev *hdev, void *data,
+				     struct sk_buff *skb)
+{
+	struct hci_ev_status *rp = data;
+	struct hci_cp_le_set_privacy_mode *cp;
+	struct hci_conn_params *params;
+
+	bt_dev_dbg(hdev, "status 0x%2.2x", rp->status);
+
+	if (rp->status)
+		return rp->status;
+
+	cp = hci_sent_cmd_data(hdev, HCI_OP_LE_SET_PRIVACY_MODE);
+	if (!cp)
+		return rp->status;
+
+	hci_dev_lock(hdev);
+
+	params = hci_conn_params_lookup(hdev, &cp->bdaddr, cp->bdaddr_type);
+	if (params)
+		params->privacy_mode = cp->mode;
+
+	hci_dev_unlock(hdev);
+
+	return rp->status;
+}
+
 static u8 hci_cc_le_set_adv_enable(struct hci_dev *hdev, void *data,
 				   struct sk_buff *skb)
 {
@@ -3887,7 +3914,8 @@ static const struct hci_cc {
 	HCI_CC_STATUS(HCI_OP_LE_REMOVE_ADV_SET, hci_cc_le_remove_adv_set),
 	HCI_CC_STATUS(HCI_OP_LE_CLEAR_ADV_SETS, hci_cc_le_clear_adv_sets),
 	HCI_CC(HCI_OP_LE_READ_TRANSMIT_POWER, hci_cc_le_read_transmit_power,
-	       sizeof(struct hci_rp_le_read_transmit_power))
+	       sizeof(struct hci_rp_le_read_transmit_power)),
+	HCI_CC_STATUS(HCI_OP_LE_SET_PRIVACY_MODE, hci_cc_le_set_privacy_mode)
 };
 
 static u8 hci_cc_func(struct hci_dev *hdev, const struct hci_cc *cc,

net/bluetooth/hci_sync.c

@@ -1597,8 +1597,40 @@ static int hci_le_add_resolve_list_sync(struct hci_dev *hdev,
 				     sizeof(cp), &cp, HCI_CMD_TIMEOUT);
 }
 
+/* Set Device Privacy Mode. */
+static int hci_le_set_privacy_mode_sync(struct hci_dev *hdev,
+					struct hci_conn_params *params)
+{
+	struct hci_cp_le_set_privacy_mode cp;
+	struct smp_irk *irk;
+
+	/* If device privacy mode has already been set there is nothing to do */
+	if (params->privacy_mode == HCI_DEVICE_PRIVACY)
+		return 0;
+
+	/* Check if HCI_CONN_FLAG_DEVICE_PRIVACY has been set as it also
+	 * indicates that LL Privacy has been enabled and
+	 * HCI_OP_LE_SET_PRIVACY_MODE is supported.
+	 */
+	if (!test_bit(HCI_CONN_FLAG_DEVICE_PRIVACY, params->flags))
+		return 0;
+
+	irk = hci_find_irk_by_addr(hdev, &params->addr, params->addr_type);
+	if (!irk)
+		return 0;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.bdaddr_type = irk->addr_type;
+	bacpy(&cp.bdaddr, &irk->bdaddr);
+	cp.mode = HCI_DEVICE_PRIVACY;
+
+	return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_PRIVACY_MODE,
+				     sizeof(cp), &cp, HCI_CMD_TIMEOUT);
+}
+
 /* Adds connection to allow list if needed, if the device uses RPA (has IRK)
- * this attempts to program the device in the resolving list as well.
+ * this attempts to program the device in the resolving list as well and
+ * properly set the privacy mode.
  */
 static int hci_le_add_accept_list_sync(struct hci_dev *hdev,
 				       struct hci_conn_params *params,
@@ -1607,11 +1639,6 @@ static int hci_le_add_accept_list_sync(struct hci_dev *hdev,
 	struct hci_cp_le_add_to_accept_list cp;
 	int err;
 
-	/* Already in accept list */
-	if (hci_bdaddr_list_lookup(&hdev->le_accept_list, &params->addr,
-				   params->addr_type))
-		return 0;
-
 	/* Select filter policy to accept all advertising */
 	if (*num_entries >= hdev->le_accept_list_size)
 		return -ENOSPC;
@@ -1637,6 +1664,18 @@ static int hci_le_add_accept_list_sync(struct hci_dev *hdev,
 		return err;
 	}
 
+	/* Set Privacy Mode */
+	err = hci_le_set_privacy_mode_sync(hdev, params);
+	if (err) {
+		bt_dev_err(hdev, "Unable to set privacy mode: %d", err);
+		return err;
+	}
+
+	/* Check if already in accept list */
+	if (hci_bdaddr_list_lookup(&hdev->le_accept_list, &params->addr,
+				   params->addr_type))
+		return 0;
+
 	*num_entries += 1;
 	cp.bdaddr_type = params->addr_type;
 	bacpy(&cp.bdaddr, &params->addr);