[1/2] cdc_ncm: Handle multicast Ethernet traffic

[1/2] cdc_ncm: Handle multicast Ethernet traffic

[Greg KH]

On Fri, Jun 29, 2018 at 04:47:28PM +0200, Miguel Rodríguez Pérez wrote:
> Some CDC_NCM devices are used as docks for laptops. In this case, it
> makes sense to accept multicast Ethernet traffic, as these devices
> can reside in a proper LAN. Without this, mDNS or IPv6 simply do not
> work.
> 
> Signed-off-by: Miguel Rodríguez Pérez <miguel@det.uvigo.gal>
> ---
>  drivers/net/usb/cdc_ncm.c | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)

This had the same subject as the previous patch, which is not correct.

Also, please use scripts/get_maintainer.pl to determine what lists to
send this to, you need to add the netdev list for it to be picked up
properly.

thanks,

greg k-h
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[1/2] cdc_ncm: Handle multicast Ethernet traffic

[Miguel Rodríguez Pérez]

There is nothing wrong with it, but there was no way cdc_ncm driver
could use it, as it currently overwrites the struct net_device_ops, so
the usbnet function set_rx_mode was not ever getting called.

This patch restores the right behavior, so that usbnet's set _rx_mode
gets called again for cdn_ncm devices. The second patch (the one with
the wrong subject) hooks into set_rx_mode to accept multicast traffic
when asked to do so.

Regards.

On 29/06/18 22:37, Oliver Neukum wrote:
> On Fr, 2018-06-29 at 16:45 +0200, Miguel Rodríguez Pérez  wrote:
>> Subject: [PATCH 1/2] Hook into usbnet_change_mtu respecting usbnet
>> driver_info
>>
>> Change the way cdc_ncm_change_mtu hooks into the netdev_ops
>> structure so that changes into usbnet driver_info operations
>> can be respected. Without this, is was not possible to hook
>> into usbnet_set_rx_mode.
> 
> Hi,
> 
> what is wrong with the existing hook?
> 
> static void __handle_set_rx_mode(struct usbnet *dev)
> {
>         if (dev->driver_info->set_rx_mode)
>                 (dev->driver_info->set_rx_mode)(dev);
> 
>         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
> }
> 
> If you cannot use it, I would prefer you to actually fix that.
> 
> 	Regards
> 		Oliver
>

[1/2] cdc_ncm: Handle multicast Ethernet traffic

[Miguel Rodríguez Pérez]

There is nothing wrong with it, but there was no way cdc_ncm driver
could use it, as it currently overwrites the struct net_device_ops, so
the usbnet function set_rx_mode was not ever getting called.

This patch restores the right behavior, so that usbnet's set _rx_mode
gets called again for cdn_ncm devices. The second patch (the one with
the wrong subject) hooks into set_rx_mode to accept multicast traffic
when asked to do so.

Regards.

On 29/06/18 22:37, Oliver Neukum wrote:
> On Fr, 2018-06-29 at 16:45 +0200, Miguel Rodríguez Pérez  wrote:
>> Subject: [PATCH 1/2] Hook into usbnet_change_mtu respecting usbnet
>> driver_info
>>
>> Change the way cdc_ncm_change_mtu hooks into the netdev_ops
>> structure so that changes into usbnet driver_info operations
>> can be respected. Without this, is was not possible to hook
>> into usbnet_set_rx_mode.
> 
> Hi,
> 
> what is wrong with the existing hook?
> 
> static void __handle_set_rx_mode(struct usbnet *dev)
> {
>         if (dev->driver_info->set_rx_mode)
>                 (dev->driver_info->set_rx_mode)(dev);
> 
>         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
> }
> 
> If you cannot use it, I would prefer you to actually fix that.
> 
> 	Regards
> 		Oliver
>

[1/2] cdc_ncm: Handle multicast Ethernet traffic

[Oliver Neukum]

On Fr, 2018-06-29 at 16:45 +0200, Miguel Rodríguez Pérez  wrote:
> Subject: [PATCH 1/2] Hook into usbnet_change_mtu respecting usbnet
> driver_info
> 
> Change the way cdc_ncm_change_mtu hooks into the netdev_ops
> structure so that changes into usbnet driver_info operations
> can be respected. Without this, is was not possible to hook
> into usbnet_set_rx_mode.

Hi,

what is wrong with the existing hook?

static void __handle_set_rx_mode(struct usbnet *dev)
{
        if (dev->driver_info->set_rx_mode)
                (dev->driver_info->set_rx_mode)(dev);

        clear_bit(EVENT_SET_RX_MODE, &dev->flags);
}

If you cannot use it, I would prefer you to actually fix that.

	Regards
		Oliver
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[1/2] cdc_ncm: Handle multicast Ethernet traffic

[Miguel Rodríguez Pérez]

Some CDC_NCM devices are used as docks for laptops. In this case, it
makes sense to accept multicast Ethernet traffic, as these devices
can reside in a proper LAN. Without this, mDNS or IPv6 simply do not
work.

Signed-off-by: Miguel Rodríguez Pérez <miguel@det.uvigo.gal>
---
 drivers/net/usb/cdc_ncm.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

 	.get_link          = usbnet_get_link,
 	.nway_reset        = usbnet_nway_reset,
@@ -1652,6 +1679,7 @@ 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 = cdc_ncm_update_filter,
 };

 /* Same as cdc_ncm_info, but with FLAG_WWAN */

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d6b51e2b9495..50af1d9d0102 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -132,6 +132,33 @@ static void cdc_ncm_get_strings(struct net_device
__always_unused *netdev, u32 s

 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32
new_tx);

+static void cdc_ncm_update_filter(struct usbnet *dev)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+	struct net_device *net = dev->net;
+
+	u16 cdc_filter = USB_CDC_PACKET_TYPE_DIRECTED
+			| USB_CDC_PACKET_TYPE_BROADCAST;
+
+	/* filtering on the device is an optional feature and not worth
+	 * the hassle so we just roughly care about snooping and if any
+	 * multicast is requested, we take every multicast
+	 */
+	if (net->flags & IFF_PROMISC)
+		cdc_filter |= USB_CDC_PACKET_TYPE_PROMISCUOUS;
+	if (!netdev_mc_empty(net) || (net->flags & IFF_ALLMULTI))
+		cdc_filter |= USB_CDC_PACKET_TYPE_ALL_MULTICAST;
+
+	usbnet_write_cmd(dev,
+			USB_CDC_SET_ETHERNET_PACKET_FILTER,
+			USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
+			cdc_filter,
+			iface_no,
+			NULL,
+			0);
+}
+
 static const struct ethtool_ops cdc_ncm_ethtool_ops = {

[1/2] cdc_ncm: Handle multicast Ethernet traffic

[Miguel Rodríguez Pérez]

Subject: [PATCH 1/2] Hook into usbnet_change_mtu respecting usbnet
driver_info

Change the way cdc_ncm_change_mtu hooks into the netdev_ops
structure so that changes into usbnet driver_info operations
can be respected. Without this, is was not possible to hook
into usbnet_set_rx_mode.

Signed-off-by: Miguel Rodríguez Pérez <miguel@det.uvigo.gal>
---
 drivers/net/usb/cdc_ncm.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

u8 data_altsetting, int drvflags)
 {
@@ -939,6 +930,8 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct
usb_interface *intf, u8 data_
 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;

 	/* must handle MTU changes */
+	cdc_ncm_netdev_ops = *dev->net->netdev_ops;
+	cdc_ncm_netdev_ops.ndo_change_mtu = cdc_ncm_change_mtu;
 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 9e1b74590682..d6b51e2b9495 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -750,16 +750,7 @@ int cdc_ncm_change_mtu(struct net_device *net, int
new_mtu)
 }
 EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);

-static const struct net_device_ops cdc_ncm_netdev_ops = {
-	.ndo_open	     = usbnet_open,
-	.ndo_stop	     = usbnet_stop,
-	.ndo_start_xmit	     = usbnet_start_xmit,
-	.ndo_tx_timeout	     = usbnet_tx_timeout,
-	.ndo_get_stats64     = usbnet_get_stats64,
-	.ndo_change_mtu	     = cdc_ncm_change_mtu,
-	.ndo_set_mac_address = eth_mac_addr,
-	.ndo_validate_addr   = eth_validate_addr,
-};
+static struct net_device_ops cdc_ncm_netdev_ops;

 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf,