[PATCH v3 2/2] Bluetooth: btusb: Read the supported features of Microsoft vendor extension

[Miao-chen Chou]

This adds a new header to facilitate the opcode and packet structures of
vendor extension(s). For now, we add only the
HCI_VS_MSFT_Read_Supported_Features command from Microsoft vendor
extension. See https://docs.microsoft.com/en-us/windows-hardware/drivers/
bluetooth/microsoft-defined-bluetooth-hci-commands-and-events#
microsoft-defined-bluetooth-hci-events for more details.
Upon initialization of a hci_dev, we issue a
HCI_VS_MSFT_Read_Supported_Features command to read the supported features
of Microsoft vendor extension if the opcode of Microsoft vendor extension
is valid. See https://docs.microsoft.com/en-us/windows-hardware/drivers/
bluetooth/microsoft-defined-bluetooth-hci-commands-and-events#
hci_vs_msft_read_supported_features for more details.
This was verified on a device with Intel ThunderPeak BT controller where
the Microsoft vendor extension features are 0x000000000000003f.

Signed-off-by: Miao-chen Chou <mcchou@xxxxxxxxxxxx>
---

Changes in v3:
- Introduce msft_vnd_ext_do_open() and msft_vnd_ext_do_close().

 net/bluetooth/hci_core.c | 95 ++++++++++++++++++++++++++++++++++++++++
 net/bluetooth/msft.c     | 27 ++++++++++++
 2 files changed, 122 insertions(+)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 286294540bed..1062692e8612 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1408,6 +1408,87 @@ static void hci_dev_get_bd_addr_from_property(struct hci_dev *hdev)
 	bacpy(&hdev->public_addr, &ba);
 }
 
+static void process_msft_vnd_ext_cmd_complete(struct hci_dev *hdev,
+					       struct sk_buff *skb)
+{
+	struct msft_cmd_cmp_info *info = (void *)skb->data;
+	struct msft_vnd_ext *msft_ext = (struct msft_vnd_ext *)hdev->msft_ext;
+	const u8 status = info->status;
+	const u16 sub_opcode = __le16_to_cpu(info->sub_opcode);
+
+	skb_pull(skb, sizeof(*info));
+
+	if (IS_ERR(skb)) {
+		bt_dev_warn(hdev, "Microsoft extension response packet invalid");
+		return;
+	}
+
+	if (status) {
+		bt_dev_warn(hdev, "Microsoft extension sub command 0x%2.2x failed",
+			    sub_opcode);
+		return;
+	}
+
+	bt_dev_dbg(hdev, "status 0x%2.2x sub opcode 0x%2.2x", status,
+		   sub_opcode);
+
+	switch (sub_opcode) {
+	case MSFT_OP_READ_SUPPORTED_FEATURES: {
+		struct msft_rp_read_supported_features *rp = (void *)skb->data;
+		u8 prefix_len = rp->evt_prefix_len;
+
+		msft_ext->features = __le64_to_cpu(rp->features);
+		msft_ext->evt_prefix_len = prefix_len;
+		msft_ext->evt_prefix = kmalloc(prefix_len, GFP_ATOMIC);
+		if (!msft_ext->evt_prefix) {
+			bt_dev_warn(hdev, "Microsoft extension invalid event prefix");
+			return;
+		}
+
+		memcpy(msft_ext->evt_prefix, rp->evt_prefix, prefix_len);
+		bt_dev_info(hdev, "Microsoft extension features 0x%016llx",
+			    msft_ext->features);
+		break;
+	}
+	default:
+		bt_dev_warn(hdev, "Microsoft extension unknown sub opcode 0x%2.2x",
+			    sub_opcode);
+		break;
+	}
+}
+
+static bool msft_vnd_ext_supported(struct hci_dev *hdev)
+{
+	struct msft_vnd_ext *msft_ext = (struct msft_vnd_ext *)hdev->msft_ext;
+
+	return msft_ext->opcode != HCI_OP_NOP;
+}
+
+static void msft_vnd_ext_do_open(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+	struct msft_vnd_ext *msft_ext = (struct msft_vnd_ext *)hdev->msft_ext;
+	struct msft_cp_read_supported_features cp;
+
+	msft_ext->features = 0;
+	msft_ext->evt_prefix_len = 0;
+	msft_ext->evt_prefix = NULL;
+
+	if (!msft_vnd_ext_supported(hdev))
+		return;
+
+	cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;
+	skb = __hci_cmd_sync(hdev, msft_ext->opcode, sizeof(cp), &cp,
+			     HCI_CMD_TIMEOUT);
+
+	process_msft_vnd_ext_cmd_complete(hdev, skb);
+
+	if (skb) {
+		kfree_skb(skb);
+		skb = NULL;
+	}
+}
+
 static int hci_dev_do_open(struct hci_dev *hdev)
 {
 	int ret = 0;
@@ -1555,6 +1636,8 @@ static int hci_dev_do_open(struct hci_dev *hdev)
 		}
 	}
 
+	msft_vnd_ext_do_open(hdev);
+
 	/* If the HCI Reset command is clearing all diagnostic settings,
 	 * then they need to be reprogrammed after the init procedure
 	 * completed.
@@ -1685,6 +1768,16 @@ static void hci_pend_le_actions_clear(struct hci_dev *hdev)
 	BT_DBG("All LE pending actions cleared");
 }
 
+static void msft_vnd_ext_do_close(struct hci_dev *hdev)
+{
+	struct msft_vnd_ext *msft_ext = (struct msft_vnd_ext *)hdev->msft_ext;
+
+	msft_ext->features = 0;
+	msft_ext->evt_prefix_len = 0;
+	kfree(msft_ext->evt_prefix);
+	msft_ext->evt_prefix = NULL;
+}
+
 int hci_dev_do_close(struct hci_dev *hdev)
 {
 	bool auto_off;
@@ -1734,6 +1827,8 @@ int hci_dev_do_close(struct hci_dev *hdev)
 			cancel_delayed_work_sync(&adv_instance->rpa_expired_cb);
 	}
 
+	msft_vnd_ext_do_close(hdev);
+
 	/* Avoid potential lockdep warnings from the *_flush() calls by
 	 * ensuring the workqueue is empty up front.
 	 */
diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
index c7ede27095be..21cb32105206 100644
--- a/net/bluetooth/msft.c
+++ b/net/bluetooth/msft.c
@@ -20,6 +20,33 @@
 // COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
 // SOFTWARE IS DISCLAIMED.
 
+#define MSFT_EVT_PREFIX_MAX_LEN			255
+
 struct msft_vnd_ext {
 	__u16	opcode;
+	__u64	features;
+	__u8	evt_prefix_len;
+	__u8	*evt_prefix;
 };
+
+struct msft_cmd_cmp_info {
+	__u8 status;
+	__u8 sub_opcode;
+} __packed;
+
+/* Microsoft Vendor HCI subcommands */
+#define MSFT_OP_READ_SUPPORTED_FEATURES		0x00
+#define MSFT_FEATURE_MASK_RSSI_MONITOR_BREDR_CONN	0x0000000000000001
+#define MSFT_FEATURE_MASK_RSSI_MONITOR_LE_CONN		0x0000000000000002
+#define MSFT_FEATURE_MASK_RSSI_MONITOR_LE_ADV		0x0000000000000004
+#define MSFT_FEATURE_MASK_ADV_MONITOR_LE_ADV		0x0000000000000008
+#define MSFT_FEATURE_MASK_VERIFY_CURVE			0x0000000000000010
+#define MSFT_FEATURE_MASK_CONCURRENT_ADV_MONITOR	0x0000000000000020
+struct msft_cp_read_supported_features {
+	__u8 sub_opcode;
+} __packed;
+struct msft_rp_read_supported_features {
+	__u64 features;
+	__u8  evt_prefix_len;
+	__u8  evt_prefix[0];
+} __packed;
-- 
2.24.1