Bluetooth: Introduce a new HCI_BREDR_ENABLED flag

To allow treating dual-mode (BR/EDR/LE) controllers as single-mode ones
(LE-only) we want to introduce a new HCI_BREDR_ENABLED flag to track
whether BR/EDR is enabled or not (previously we simply looked at the
feature bit with lmp_bredr_enabled).

This patch add the new flag and updates the relevant places to test
against it instead of using lmp_bredr_enabled. The flag is by default
enabled when registering an adapter and only cleared if necessary once
the local features have been read during the HCI init procedure.

We cannot completely block BR/EDR usage in case user space uses raw HCI
sockets but the patch tries to block this in places where possible, such
as the various BR/EDR specific ioctls.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 19 insertions, 2 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 7cbdd33d9b38..14df032543b2 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -519,6 +519,8 @@ static void hci_init2_req(struct hci_request *req, unsigned long opt)
 
 	if (lmp_bredr_capable(hdev))
 		bredr_setup(req);
+	else
+		clear_bit(HCI_BREDR_ENABLED, &hdev->dev_flags);
 
 	if (lmp_le_capable(hdev))
 		le_setup(req);
@@ -1034,6 +1036,11 @@ int hci_inquiry(void __user *arg)
 		goto done;
 	}
 
+	if (!test_bit(HCI_BREDR_ENABLED, &hdev->dev_flags)) {
+		err = -EOPNOTSUPP;
+		goto done;
+	}
+
 	hci_dev_lock(hdev);
 	if (inquiry_cache_age(hdev) > INQUIRY_CACHE_AGE_MAX ||
 	    inquiry_cache_empty(hdev) || ir.flags & IREQ_CACHE_FLUSH) {
@@ -1101,7 +1108,7 @@ static u8 create_ad(struct hci_dev *hdev, u8 *ptr)
 	if (test_bit(HCI_LE_PERIPHERAL, &hdev->dev_flags))
 		flags |= LE_AD_GENERAL;
 
-	if (!lmp_bredr_capable(hdev))
+	if (!test_bit(HCI_BREDR_ENABLED, &hdev->dev_flags))
 		flags |= LE_AD_NO_BREDR;
 
 	if (lmp_le_br_capable(hdev))
@@ -1493,6 +1500,11 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
 		goto done;
 	}
 
+	if (!test_bit(HCI_BREDR_ENABLED, &hdev->dev_flags)) {
+		err = -EOPNOTSUPP;
+		goto done;
+	}
+
 	switch (cmd) {
 	case HCISETAUTH:
 		err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt,
@@ -2318,8 +2330,13 @@ int hci_register_dev(struct hci_dev *hdev)
 
 	set_bit(HCI_SETUP, &hdev->dev_flags);
 
-	if (hdev->dev_type != HCI_AMP)
+	if (hdev->dev_type != HCI_AMP) {
 		set_bit(HCI_AUTO_OFF, &hdev->dev_flags);
+		/* Assume BR/EDR support until proven otherwise (such as
+		 * through reading supported features during init.
+		 */
+		set_bit(HCI_BREDR_ENABLED, &hdev->dev_flags);
+	}
 
 	write_lock(&hci_dev_list_lock);
 	list_add(&hdev->list, &hci_dev_list);