Bluetooth: Fix sending write_le_host_supporte for LE-only controllers

The Bluetooth Core Specification (4.0) defines the Write LE Host
Supported HCI command as only available for controllers supporting
BR/EDR. This is further reflected in the Read Local Extended Features
HCI command also not being available for LE-only controllers. In other
words, host-side LE support is implicit for single-mode LE controllers
and doesn't have explicit HCI-level enablement.

This patch ensures that the LE setting is always exposed as enabled
through mgmt and returns a "rejected" response if user space tries to
toggle the setting. The patch also ensures that Write LE Host Supported
is never sent for LE-only controllers.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 4c830c6..35fef227 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1351,6 +1351,11 @@
 		return cmd_status(sk, hdev->id, MGMT_OP_SET_LE,
 				  MGMT_STATUS_INVALID_PARAMS);
 
+	/* LE-only devices do not allow toggling LE on/off */
+	if (!lmp_bredr_capable(hdev))
+		return cmd_status(sk, hdev->id, MGMT_OP_SET_LE,
+				  MGMT_STATUS_REJECTED);
+
 	hci_dev_lock(hdev);
 
 	val = !!cp->val;
@@ -3347,7 +3352,8 @@
 		hci_req_add(&req, HCI_OP_WRITE_SSP_MODE, 1, &ssp);
 	}
 
-	if (test_bit(HCI_LE_ENABLED, &hdev->dev_flags)) {
+	if (test_bit(HCI_LE_ENABLED, &hdev->dev_flags) &&
+	    lmp_bredr_capable(hdev)) {
 		struct hci_cp_write_le_host_supported cp;
 
 		cp.le = 1;