[PATCH net-next] net: usb: cdc-ncm: check for filtering capability

[PATCH net-next] net: usb: cdc-ncm: check for filtering capability

[Oliver Neukum]

If the decice does not support filtering, filtering
must not be used and all packets delivered for the
upper layers to sort.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/usb/cdc_ncm.c   | 20 ++++++++++++++++----
 include/linux/usb/cdc_ncm.h |  1 +
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 34e82f1e37d9..ea0e5e276cd6 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -892,6 +892,10 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 		}
 	}
 
+	if (ctx->func_desc)
+		ctx->filtering_supported = !!(ctx->func_desc->bmNetworkCapabilities
+			& USB_CDC_NCM_NCAP_ETH_FILTER);
+
 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
 
 	/* Device-specific flags */
@@ -1898,6 +1902,14 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
 	}
 }
 
+static void cdc_ncm_update_filter(struct usbnet *dev)
+{
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+	if (ctx->filtering_supported)
+		usbnet_cdc_update_filter(dev);
+}
+
 static const struct driver_info cdc_ncm_info = {
 	.description = "CDC NCM (NO ZLP)",
 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
@@ -1908,7 +1920,7 @@ static const struct driver_info cdc_ncm_info = {
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,
 	.tx_fixup = cdc_ncm_tx_fixup,
-	.set_rx_mode = usbnet_cdc_update_filter,
+	.set_rx_mode = cdc_ncm_update_filter,
 };
 
 /* Same as cdc_ncm_info, but with FLAG_SEND_ZLP  */
@@ -1922,7 +1934,7 @@ static const struct driver_info cdc_ncm_zlp_info = {
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,
 	.tx_fixup = cdc_ncm_tx_fixup,
-	.set_rx_mode = usbnet_cdc_update_filter,
+	.set_rx_mode = cdc_ncm_update_filter,
 };
 
 /* Same as cdc_ncm_info, but with FLAG_SEND_ZLP */
@@ -1964,7 +1976,7 @@ static const struct driver_info wwan_info = {
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,
 	.tx_fixup = cdc_ncm_tx_fixup,
-	.set_rx_mode = usbnet_cdc_update_filter,
+	.set_rx_mode = cdc_ncm_update_filter,
 };
 
 /* Same as wwan_info, but with FLAG_NOARP  */
@@ -1978,7 +1990,7 @@ static const struct driver_info wwan_noarp_info = {
 	.status = cdc_ncm_status,
 	.rx_fixup = cdc_ncm_rx_fixup,
 	.tx_fixup = cdc_ncm_tx_fixup,
-	.set_rx_mode = usbnet_cdc_update_filter,
+	.set_rx_mode = cdc_ncm_update_filter,
 };
 
 static const struct usb_device_id cdc_devs[] = {
diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index 2d207cb4837d..4ac082a63173 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -119,6 +119,7 @@ struct cdc_ncm_ctx {
 	u32 timer_interval;
 	u32 max_ndp_size;
 	u8 is_ndp16;
+	u8 filtering_supported;
 	union {
 		struct usb_cdc_ncm_ndp16 *delayed_ndp16;
 		struct usb_cdc_ncm_ndp32 *delayed_ndp32;
-- 
2.50.1

Re: [PATCH net-next] net: usb: cdc-ncm: check for filtering capability

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 17 Jul 2025 14:06:17 +0200 you wrote:
> If the decice does not support filtering, filtering
> must not be used and all packets delivered for the
> upper layers to sort.
> 
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> ---
>  drivers/net/usb/cdc_ncm.c   | 20 ++++++++++++++++----
>  include/linux/usb/cdc_ncm.h |  1 +
>  2 files changed, 17 insertions(+), 4 deletions(-)

Here is the summary with links:
  - [net-next] net: usb: cdc-ncm: check for filtering capability
    https://git.kernel.org/netdev/net-next/c/61c3e8940f2d

You are awesome, thank you!
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