Bluetooth: mgmt: Add support for Set Link Security command

The Set Link Security mgmt command is used to enable or disable link
level security, also known as Security Mode 3. This is rarely enabled in
modern systems but the command needs to be available for completeness,
qualification purposes and those few systems that actually want to
enable it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -994,6 +994,7 @@ int mgmt_user_passkey_neg_reply_complete(struct hci_dev *hdev, bdaddr_t *bdaddr,
 					u8 link_type, u8 addr_type, u8 status);
 int mgmt_auth_failed(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 						u8 addr_type, u8 status);
+int mgmt_auth_enable_complete(struct hci_dev *hdev, u8 status);
 int mgmt_set_local_name_complete(struct hci_dev *hdev, u8 *name, u8 status);
 int mgmt_read_local_oob_data_reply_complete(struct hci_dev *hdev, u8 *hash,
 						u8 *randomizer, u8 status);

net/bluetooth/hci_event.c

@@ -254,6 +254,9 @@ static void hci_cc_write_auth_enable(struct hci_dev *hdev, struct sk_buff *skb)
 			clear_bit(HCI_AUTH, &hdev->flags);
 	}
 
+	if (test_bit(HCI_MGMT, &hdev->dev_flags))
+		mgmt_auth_enable_complete(hdev, status);
+
 	hci_req_complete(hdev, HCI_OP_WRITE_AUTH_ENABLE, status);
 }
 

net/bluetooth/mgmt.c

@@ -964,6 +964,65 @@ static int set_pairable(struct sock *sk, u16 index, void *data, u16 len)
 	return err;
 }
 
+static int set_link_security(struct sock *sk, u16 index, void *data, u16 len)
+{
+	struct mgmt_mode *cp = data;
+	struct pending_cmd *cmd;
+	struct hci_dev *hdev;
+	uint8_t val;
+	int err;
+
+	BT_DBG("request for hci%u", index);
+
+	if (len != sizeof(*cp))
+		return cmd_status(sk, index, MGMT_OP_SET_LINK_SECURITY,
+						MGMT_STATUS_INVALID_PARAMS);
+
+	hdev = hci_dev_get(index);
+	if (!hdev)
+		return cmd_status(sk, index, MGMT_OP_SET_LINK_SECURITY,
+						MGMT_STATUS_INVALID_PARAMS);
+
+	hci_dev_lock(hdev);
+
+	if (!test_bit(HCI_UP, &hdev->flags)) {
+		err = cmd_status(sk, index, MGMT_OP_SET_LINK_SECURITY,
+						MGMT_STATUS_NOT_POWERED);
+		goto failed;
+	}
+
+	if (mgmt_pending_find(MGMT_OP_SET_LINK_SECURITY, hdev)) {
+		err = cmd_status(sk, index, MGMT_OP_SET_LINK_SECURITY,
+							MGMT_STATUS_BUSY);
+		goto failed;
+	}
+
+	val = !!cp->val;
+
+	if (test_bit(HCI_AUTH, &hdev->flags) == val) {
+		err = send_settings_rsp(sk, MGMT_OP_SET_LINK_SECURITY, hdev);
+		goto failed;
+	}
+
+	cmd = mgmt_pending_add(sk, MGMT_OP_SET_LINK_SECURITY, hdev, data, len);
+	if (!cmd) {
+		err = -ENOMEM;
+		goto failed;
+	}
+
+	err = hci_send_cmd(hdev, HCI_OP_WRITE_AUTH_ENABLE, sizeof(val), &val);
+	if (err < 0) {
+		mgmt_pending_remove(cmd);
+		goto failed;
+	}
+
+failed:
+	hci_dev_unlock(hdev);
+	hci_dev_put(hdev);
+
+	return err;
+}
+
 static int add_uuid(struct sock *sk, u16 index, void *data, u16 len)
 {
 	struct mgmt_cp_add_uuid *cp = data;
@@ -2443,6 +2502,9 @@ int mgmt_control(struct sock *sk, struct msghdr *msg, size_t msglen)
 	case MGMT_OP_SET_PAIRABLE:
 		err = set_pairable(sk, index, cp, len);
 		break;
+	case MGMT_OP_SET_LINK_SECURITY:
+		err = set_link_security(sk, index, cp, len);
+		break;
 	case MGMT_OP_ADD_UUID:
 		err = add_uuid(sk, index, cp, len);
 		break;
@@ -2965,6 +3027,31 @@ int mgmt_auth_failed(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 	return mgmt_event(MGMT_EV_AUTH_FAILED, hdev, &ev, sizeof(ev), NULL);
 }
 
+int mgmt_auth_enable_complete(struct hci_dev *hdev, u8 status)
+{
+	struct cmd_lookup match = { NULL, hdev };
+	__le32 ev;
+	int err;
+
+	if (status) {
+		u8 mgmt_err = mgmt_status(status);
+		mgmt_pending_foreach(MGMT_OP_SET_LINK_SECURITY, hdev,
+						cmd_status_rsp, &mgmt_err);
+		return 0;
+	}
+
+	mgmt_pending_foreach(MGMT_OP_SET_LINK_SECURITY, hdev, settings_rsp,
+								&match);
+
+	ev = cpu_to_le32(get_current_settings(hdev));
+	err = mgmt_event(MGMT_EV_NEW_SETTINGS, hdev, &ev, sizeof(ev), match.sk);
+
+	if (match.sk)
+		sock_put(match.sk);
+
+	return err;
+}
+
 int mgmt_set_local_name_complete(struct hci_dev *hdev, u8 *name, u8 status)
 {
 	struct pending_cmd *cmd;