Bluetooth: Don't bother user space without IO capabilities

If user space has a NoInputNoOutput IO capability it makes no sense to
bother it with confirmation requests. This patch updates both SSP and
SMP to check for the local IO capability before sending a user
confirmation request to user space.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_event.c

@@ -3752,9 +3752,11 @@ static void hci_user_confirm_request_evt(struct hci_dev *hdev,
 		/* If we're not the initiators request authorization to
 		 * proceed from user space (mgmt_user_confirm with
 		 * confirm_hint set to 1). The exception is if neither
-		 * side had MITM in which case we do auto-accept.
+		 * side had MITM or if the local IO capability is
+		 * NoInputNoOutput, in which case we do auto-accept
 		 */
 		if (!test_bit(HCI_CONN_AUTH_PEND, &conn->flags) &&
+		    conn->io_capability != HCI_IO_NO_INPUT_OUTPUT &&
 		    (loc_mitm || rem_mitm)) {
 			BT_DBG("Confirming auto-accept as acceptor");
 			confirm_hint = 1;

net/bluetooth/smp.c

@@ -431,6 +431,10 @@ static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
 	if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
 		method = JUST_WORKS;
 
+	/* Don't bother user space with no IO capabilities */
+	if (method == JUST_CFM && hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
+		method = JUST_WORKS;
+
 	/* If Just Works, Continue with Zero TK */
 	if (method == JUST_WORKS) {
 		set_bit(SMP_FLAG_TK_VALID, &smp->flags);