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From: Ying Hsu <yinghsu@chromium.org>
To: linux-bluetooth@vger.kernel.org
Cc: chromeos-bluetooth-upstreaming@chromium.org,
	Ying Hsu <yinghsu@chromium.org>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	Marcel Holtmann <marcel@holtmann.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] Bluetooth: vendor specific ISO data packet identification by handle
Date: Wed, 22 May 2024 11:11:37 +0000
Message-ID: <20240522111139.2612601-1-yinghsu@chromium.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

When HCI raw sockets are opened, the Bluetooth kernel module doesn't
track CIS/BIS connections. User-space applications have to identify
ISO data by maintaining connection information and look up the mapping
for each ACL data packet received. Besides, btsnoop log catpured in
kernel would couldn't tell ISO data from ACL data in this case.

By differentiating ISO data from ACL data earlier in btusb, we can
eliminate unnecessary lookups and improve btsnoop log clarity.
This patch enables vendor-specific differentiation between ISO and
ACL data packets.

Signed-off-by: Ying Hsu <yinghsu@chromium.org>
---
Tested LE unicast recording on a ChromeOS device with Intel AX211

 drivers/bluetooth/btusb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 79aefdb3324d..543961b6c671 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -889,6 +889,8 @@ struct btusb_data {
 	int (*recv_acl)(struct hci_dev *hdev, struct sk_buff *skb);
 	int (*recv_bulk)(struct btusb_data *data, void *buffer, int count);
 
+	int (*is_iso_data_pkt)(struct sk_buff *skb);
+
 	int (*setup_on_usb)(struct hci_dev *hdev);
 
 	int oob_wake_irq;   /* irq for out-of-band wake-on-bt */
@@ -1229,6 +1231,8 @@ static int btusb_recv_bulk(struct btusb_data *data, void *buffer, int count)
 
 		if (!hci_skb_expect(skb)) {
 			/* Complete frame */
+			if (data->is_iso_data_pkt && data->is_iso_data_pkt(skb))
+				hci_skb_pkt_type(skb) = HCI_ISODATA_PKT;
 			btusb_recv_acl(data, skb);
 			skb = NULL;
 		}
@@ -2539,6 +2543,13 @@ static int btusb_recv_bulk_intel(struct btusb_data *data, void *buffer,
 	return btusb_recv_bulk(data, buffer, count);
 }
 
+static int btusb_is_iso_data_pkt_intel(struct sk_buff *skb)
+{
+	__u16 handle = (__le16_to_cpu(hci_acl_hdr(skb)->handle) & 0xfff);
+
+	return (handle >= 0x900);
+}
+
 static int btusb_send_frame_intel(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct urb *urb;
@@ -4361,6 +4372,9 @@ static int btusb_probe(struct usb_interface *intf,
 		/* Override the rx handlers */
 		data->recv_event = btintel_recv_event;
 		data->recv_bulk = btusb_recv_bulk_intel;
+
+		/* Override for ISO data packet*/
+		data->is_iso_data_pkt = btusb_is_iso_data_pkt_intel;
 	} else if (id->driver_info & BTUSB_REALTEK) {
 		/* Allocate extra space for Realtek device */
 		priv_size += sizeof(struct btrealtek_data);
-- 
2.45.1.288.g0e0cd299f1-goog