usb: device: fix Bluetooth buffer handling

In both implementation, when comparing received data length take into
account that the buffer obtained from bt_buf_get_tx() stores the type at
the top. The buffer types are H:4 and in the TX path we need to check for
BT_HCI_H4_* types not BT_BUF_*.

In the legacy implementation, the hci_acl_pkt_len() function obtains the
length from the USB transaction buffer, which does not contain a buffer
type at the top.

In the new implementation, partially revert the changes and restore
hci_pkt_get_len(), this will be required for any further changes anyway.

Fixes commit f85d63a ("Bluetooth: Remove USB H4 mode support").

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

subsys/usb/device/class/bluetooth.c

@@ -154,20 +154,20 @@ static void hci_tx_thread(void *p1, void *p2, void *p3)
 
 		type = net_buf_pull_u8(buf);
 		switch (type) {
-		case BT_BUF_EVT:
+		case BT_HCI_H4_EVT:
 			usb_transfer_sync(
 				bluetooth_ep_data[HCI_INT_EP_IDX].ep_addr,
 				buf->data, buf->len,
 				USB_TRANS_WRITE | USB_TRANS_NO_ZLP);
 			break;
-		case BT_BUF_ACL_IN:
+		case BT_HCI_H4_ACL:
 			usb_transfer_sync(
 				bluetooth_ep_data[HCI_IN_EP_IDX].ep_addr,
 				buf->data, buf->len,
 				USB_TRANS_WRITE);
 			break;
 		default:
-			LOG_ERR("Unknown type %u", type);
+			LOG_ERR("Unsupported type %u", type);
 			break;
 		}
 
@@ -200,11 +200,11 @@ static uint16_t hci_acl_pkt_len(const uint8_t *data, size_t data_len)
 	struct bt_hci_acl_hdr *acl_hdr;
 	size_t hdr_len = sizeof(*acl_hdr);
 
-	if (data_len - 1 < hdr_len) {
+	if (data_len < hdr_len) {
 		return 0;
 	}
 
-	acl_hdr = (struct bt_hci_acl_hdr *)(data + 1);
+	acl_hdr = (struct bt_hci_acl_hdr *)data;
 
 	return sys_le16_to_cpu(acl_hdr->len) + hdr_len;
 }
@@ -250,7 +250,7 @@ static void acl_read_cb(uint8_t ep, int size, void *priv)
 		LOG_DBG("len %u, chunk %u", buf->len, size);
 	}
 
-	if (buf != NULL && pkt_len == buf->len) {
+	if (buf != NULL && pkt_len == buf->len - 1) {
 		k_fifo_put(&rx_queue, buf);
 		LOG_DBG("put");
 		buf = NULL;

subsys/usb/device_next/class/bt_hci.c

@@ -210,14 +210,14 @@ static void bt_hci_tx_thread(void *p1, void *p2, void *p3)
 		type = net_buf_pull_u8(bt_buf);
 
 		switch (type) {
-		case BT_BUF_EVT:
+		case BT_HCI_H4_EVT:
 			ep = bt_hci_get_int_in(c_data);
 			break;
-		case BT_BUF_ACL_IN:
+		case BT_HCI_H4_ACL:
 			ep = bt_hci_get_bulk_in(c_data);
 			break;
 		default:
-			LOG_ERR("Unknown type %u", type);
+			LOG_ERR("Unsupported type %u", type);
 			continue;
 		}
 
@@ -273,19 +273,43 @@ static int bt_hci_acl_out_start(struct usbd_class_data *const c_data)
 	return  ret;
 }
 
-static uint16_t hci_acl_pkt_len(struct net_buf *const buf)
+static uint16_t hci_pkt_get_len(const uint8_t h4_type,
+				const uint8_t *data, const size_t size)
 {
-	struct bt_hci_acl_hdr *acl_hdr;
-	size_t hdr_len;
+	size_t hdr_len = 0;
+	uint16_t len = 0;
 
-	hdr_len = sizeof(*acl_hdr);
-	if (buf->len - 1 < hdr_len) {
-		return 0;
+	switch (h4_type) {
+	case BT_HCI_H4_CMD: {
+		struct bt_hci_cmd_hdr *cmd_hdr;
+
+		hdr_len = sizeof(*cmd_hdr);
+		cmd_hdr = (struct bt_hci_cmd_hdr *)data;
+		len = cmd_hdr->param_len + hdr_len;
+		break;
+	}
+	case BT_HCI_H4_ACL: {
+		struct bt_hci_acl_hdr *acl_hdr;
+
+		hdr_len = sizeof(*acl_hdr);
+		acl_hdr = (struct bt_hci_acl_hdr *)data;
+		len = sys_le16_to_cpu(acl_hdr->len) + hdr_len;
+		break;
 	}
+	case BT_HCI_H4_ISO: {
+		struct bt_hci_iso_hdr *iso_hdr;
 
-	acl_hdr = (struct bt_hci_acl_hdr *)(buf->data + 1);
+		hdr_len = sizeof(*iso_hdr);
+		iso_hdr = (struct bt_hci_iso_hdr *)data;
+		len = bt_iso_hdr_len(sys_le16_to_cpu(iso_hdr->len)) + hdr_len;
+		break;
+	}
+	default:
+		LOG_ERR("Unknown H4 buffer type");
+		return 0;
+	}
 
-	return sys_le16_to_cpu(acl_hdr->len) + hdr_len;
+	return (size < hdr_len) ? 0 : len;
 }
 
 static int bt_hci_acl_out_cb(struct usbd_class_data *const c_data,
@@ -305,7 +329,9 @@ static int bt_hci_acl_out_cb(struct usbd_class_data *const c_data,
 			goto restart_out_transfer;
 		}
 
-		hci_data->acl_len = hci_acl_pkt_len(hci_data->acl_buf);
+		hci_data->acl_len = hci_pkt_get_len(BT_HCI_H4_ACL,
+						    buf->data,
+						    buf->len);
 
 		LOG_DBG("acl_len %u, chunk %u", hci_data->acl_len, buf->len);
 
@@ -330,7 +356,11 @@ static int bt_hci_acl_out_cb(struct usbd_class_data *const c_data,
 		LOG_INF("len %u, chunk %u", hci_data->acl_buf->len, buf->len);
 	}
 
-	if (hci_data->acl_buf != NULL && hci_data->acl_len == hci_data->acl_buf->len) {
+	/*
+	 * The buffer obtained from bt_buf_get_tx() stores the type at the top.
+	 * Take this into account when comparing received data length.
+	 */
+	if (hci_data->acl_buf != NULL && hci_data->acl_len == hci_data->acl_buf->len - 1) {
 		k_fifo_put(&bt_hci_rx_queue, hci_data->acl_buf);
 		hci_data->acl_buf = NULL;
 		hci_data->acl_len = 0;