Subject: Re: [RFC 2/9] net: dsa: add basic support for VLAN operations

From: Guenter Roeck <[email-masked]>
Date: Mon, 01 Jun 2015 23:52:41 -0700

On 06/01/2015 06:27 PM, Vivien Didelot wrote:
> This patch adds the glue between DSA and switchdev to add and delete
> SWITCHDEV_OBJ_PORT_VLAN objects.
>
> This will allow the DSA switch drivers implementing the port_vlan_add
> and port_vlan_del functions to access the switch VLAN database through
> userspace commands such as "bridge vlan".
>
> Signed-off-by: Vivien Didelot <[email-masked]>
> ---
>   include/net/dsa.h |  7 +++++++
>   net/dsa/slave.c   | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
>   2 files changed, 66 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index fbca63b..726357b 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -302,6 +302,13 @@ struct dsa_switch_driver {
>   			   const unsigned char *addr, u16 vid);
>   	int	(*fdb_getnext)(struct dsa_switch *ds, int port,
>   			       unsigned char *addr, bool *is_static);
> +
> +	/*
> +	 * VLAN support
> +	 */
> +	int	(*port_vlan_add)(struct dsa_switch *ds, int port, u16 vid,
> +				 u16 bridge_flags);
> +	int	(*port_vlan_del)(struct dsa_switch *ds, int port, u16 vid);
>   };
>
>   void register_switch_driver(struct dsa_switch_driver *type);
> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
> index cbda00a..52ba5a1 100644
> --- a/net/dsa/slave.c
> +++ b/net/dsa/slave.c
> @@ -363,6 +363,25 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
>   	return ret;
>   }
>
> +static int dsa_slave_port_vlans_add(struct net_device *dev,
> +				    struct switchdev_obj_vlan *vlan)
> +{
> +	struct dsa_slave_priv *p = netdev_priv(dev);
> +	struct dsa_switch *ds = p->parent;
> +	int vid, err = 0;
> +
> +	if (!ds->drv->port_vlan_add)
> +		return -ENOTSUPP;
> +
> +	for (vid = vlan->vid_start; vid <= vlan->vid_end; ++vid) {
> +		err = ds->drv->port_vlan_add(ds, p->port, vid, vlan->flags);
> +		if (err)
> +			break;
> +	}
> +
> +	return err;
> +}
> +
>   static int dsa_slave_port_obj_add(struct net_device *dev,
>   				  struct switchdev_obj *obj)
>   {
> @@ -378,6 +397,9 @@ static int dsa_slave_port_obj_add(struct net_device *dev,
>   		return 0;
>
>   	switch (obj->id) {
> +	case SWITCHDEV_OBJ_PORT_VLAN:
> +		err = dsa_slave_port_vlans_add(dev, &obj->u.vlan);
> +		break;
>   	default:
>   		err = -ENOTSUPP;
>   		break;
> @@ -386,12 +408,34 @@ static int dsa_slave_port_obj_add(struct net_device *dev,
>   	return err;
>   }
>
> +static int dsa_slave_port_vlans_del(struct net_device *dev,
> +				    struct switchdev_obj_vlan *vlan)
> +{
> +	struct dsa_slave_priv *p = netdev_priv(dev);
> +	struct dsa_switch *ds = p->parent;
> +	int vid, err = 0;
> +
> +	if (!ds->drv->port_vlan_del)
> +		return -ENOTSUPP;
> +
> +	for (vid = vlan->vid_start; vid <= vlan->vid_end; ++vid) {
> +		err = ds->drv->port_vlan_del(ds, p->port, vid);
> +		if (err)
> +			break;
> +	}
> +
> +	return err;
> +}
> +
>   static int dsa_slave_port_obj_del(struct net_device *dev,
>   				  struct switchdev_obj *obj)
>   {
>   	int err;
>
>   	switch (obj->id) {
> +	case SWITCHDEV_OBJ_PORT_VLAN:
> +		err = dsa_slave_port_vlans_del(dev, &obj->u.vlan);
> +		break;
>   	default:
>   		err = -EOPNOTSUPP;
>   		break;
> @@ -473,6 +517,15 @@ static netdev_tx_t dsa_slave_notag_xmit(struct sk_buff *skb,
>   	return NETDEV_TX_OK;
>   }
>
> +static int dsa_slave_vlan_noop(struct net_device *dev, __be16 proto, u16 vid)
> +{
> +	/* NETIF_F_HW_VLAN_CTAG_FILTER requires ndo_vlan_rx_add_vid and
> +	 * ndo_vlan_rx_kill_vid, otherwise the VLAN acceleration is considered
> +	 * buggy (see net/core/dev.c).
> +	 */

As Scott mentioned, just don't set NETIF_F_HW_VLAN_CTAG_FILTER.

I don't entirely understand why we would not want to filter VLANs in the switch.
Can you explain ?

Thanks,
Guenter