Bluetooth: advertisement handling in new connect procedure

Currently, when trying to connect to already paired device that just
rotated its RPA MAC address, old address would be used and connection
would fail. In order to fix that, kernel must scan and receive
advertisement with fresh RPA before connecting.

This path makes sure that after advertisement is received from device that
we try to connect to, it is properly handled in check_pending_le_conn and
trigger connect attempt.

It also modifies hci_le_connect to make sure that connect attempt will be
properly continued.

Signed-off-by: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 37 insertions, 15 deletions

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 534feb7956a3..85c6aa5d5bbc 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -679,15 +679,18 @@ static void create_le_conn_complete(struct hci_dev *hdev, u8 status, u16 opcode)
 {
 	struct hci_conn *conn;
 
-	if (status == 0)
-		return;
+	hci_dev_lock(hdev);
+
+	conn = hci_lookup_le_connect(hdev);
+
+	if (!status) {
+		hci_connect_le_scan_cleanup(conn);
+		goto done;
+	}
 
 	BT_ERR("HCI request failed to create LE connection: status 0x%2.2x",
 	       status);
 
-	hci_dev_lock(hdev);
-
-	conn = hci_lookup_le_connect(hdev);
 	if (!conn)
 		goto done;
 
@@ -727,6 +730,7 @@ static void hci_req_add_le_create_conn(struct hci_request *req,
 	hci_req_add(req, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
 
 	conn->state = BT_CONNECT;
+	clear_bit(HCI_CONN_SCANNING, &conn->flags);
 }
 
 static void hci_req_directed_advertising(struct hci_request *req,
@@ -770,7 +774,7 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 				u8 role)
 {
 	struct hci_conn_params *params;
-	struct hci_conn *conn;
+	struct hci_conn *conn, *conn_unfinished;
 	struct smp_irk *irk;
 	struct hci_request req;
 	int err;
@@ -793,9 +797,17 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 	 * and return the object found.
 	 */
 	conn = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
+	conn_unfinished = NULL;
 	if (conn) {
-		conn->pending_sec_level = sec_level;
-		goto done;
+		if (conn->state == BT_CONNECT &&
+		    test_bit(HCI_CONN_SCANNING, &conn->flags)) {
+			BT_DBG("will continue unfinished conn %pMR", dst);
+			conn_unfinished = conn;
+		} else {
+			if (conn->pending_sec_level < sec_level)
+				conn->pending_sec_level = sec_level;
+			goto done;
+		}
 	}
 
 	/* Since the controller supports only one LE connection attempt at a
@@ -808,10 +820,6 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 	 * resolving key, the connection needs to be established
 	 * to a resolvable random address.
 	 *
-	 * This uses the cached random resolvable address from
-	 * a previous scan. When no cached address is available,
-	 * try connecting to the identity address instead.
-	 *
 	 * Storing the resolvable random address is required here
 	 * to handle connection failures. The address will later
 	 * be resolved back into the original identity address
@@ -823,15 +831,23 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 		dst_type = ADDR_LE_DEV_RANDOM;
 	}
 
-	conn = hci_conn_add(hdev, LE_LINK, dst, role);
+	if (conn_unfinished) {
+		conn = conn_unfinished;
+		bacpy(&conn->dst, dst);
+	} else {
+		conn = hci_conn_add(hdev, LE_LINK, dst, role);
+	}
+
 	if (!conn)
 		return ERR_PTR(-ENOMEM);
 
 	conn->dst_type = dst_type;
 	conn->sec_level = BT_SECURITY_LOW;
-	conn->pending_sec_level = sec_level;
 	conn->conn_timeout = conn_timeout;
 
+	if (!conn_unfinished)
+		conn->pending_sec_level = sec_level;
+
 	hci_req_init(&req, hdev);
 
 	/* Disable advertising if we're active. For master role
@@ -896,7 +912,13 @@ create_conn:
 	}
 
 done:
-	hci_conn_hold(conn);
+	/* If this is continuation of connect started by hci_connect_le_scan,
+	 * it already called hci_conn_hold and calling it again would mess the
+	 * counter.
+	 */
+	if (!conn_unfinished)
+		hci_conn_hold(conn);
+
 	return conn;
 }