Hi,
Problem background:
Most DSA switch tags shift the EtherType to the right, causing the
master to not parse the VLAN as VLAN.
However, not all switches do that (example: tail tags), and if the DSA
master has "rx-vlan-filter: on" in ethtool -k, then we have a problem.
Therefore, I was thinking we could populate the VLAN table of the
master, just in case, so that it can work with a VLAN filtering master.
It would look something like this:
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 19b98a7231ec..b8aca2301c59 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -307,9 +307,10 @@ static int dsa_slave_vlan_add(struct net_device *dev,
const struct switchdev_obj *obj,
struct switchdev_trans *trans)
{
+ struct net_device *master = dsa_slave_to_master(dev);
struct dsa_port *dp = dsa_slave_to_port(dev);
struct switchdev_obj_port_vlan vlan;
- int err;
+ int vid, err;
if (obj->orig_dev != dev)
return -EOPNOTSUPP;
@@ -336,6 +337,12 @@ static int dsa_slave_vlan_add(struct net_device *dev,
if (err)
return err;
+ for (vid = vlan.vid_begin; vid <= vlan.vid_end; vid++) {
+ err = vlan_vid_add(master, htons(ETH_P_8021Q), vid);
+ if (err)
+ return err;
+ }
+
return 0;
}
@@ -379,8 +386,10 @@ static int dsa_slave_port_obj_add(struct net_device *dev,
static int dsa_slave_vlan_del(struct net_device *dev,
const struct switchdev_obj *obj)
{
+ struct net_device *master = dsa_slave_to_master(dev);
struct dsa_port *dp = dsa_slave_to_port(dev);
struct switchdev_obj_port_vlan *vlan;
+ int vid, err;
if (obj->orig_dev != dev)
return -EOPNOTSUPP;
@@ -396,7 +405,14 @@ static int dsa_slave_vlan_del(struct net_device *dev,
/* Do not deprogram the CPU port as it may be shared with other user
* ports which can be members of this VLAN as well.
*/
- return dsa_port_vlan_del(dp, vlan);
+ err = dsa_port_vlan_del(dp, vlan);
+ if (err)
+ return err;
+
+ for (vid = vlan->vid_begin; vid <= vlan->vid_end; vid++)
+ vlan_vid_del(master, htons(ETH_P_8021Q), vid);
+
+ return 0;
}
static int dsa_slave_port_obj_del(struct net_device *dev,
@@ -1241,6 +1257,7 @@ static int dsa_slave_get_ts_info(struct net_device *dev,
static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
u16 vid)
{
+ struct net_device *master = dsa_slave_to_master(dev);
struct dsa_port *dp = dsa_slave_to_port(dev);
struct switchdev_obj_port_vlan vlan = {
.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
@@ -1294,12 +1311,13 @@ static int dsa_slave_vlan_rx_add_vid(struct net_device
*dev, __be16 proto,
if (ret)
return ret;
- return 0;
+ return vlan_vid_add(master, proto, vid);
}
static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
u16 vid)
{
+ struct net_device *master = dsa_slave_to_master(dev);
struct dsa_port *dp = dsa_slave_to_port(dev);
struct switchdev_obj_port_vlan vlan = {
.vid_begin = vid,
@@ -1332,7 +1350,13 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device
*dev, __be16 proto,
/* Do not deprogram the CPU port as it may be shared with other user
* ports which can be members of this VLAN as well.
*/
- return dsa_port_vlan_del(dp, &vlan);
+ ret = dsa_port_vlan_del(dp, &vlan);
+ if (ret)
+ return ret;
+
+ vlan_vid_del(master, proto, vid);
+
+ return 0;
}
struct dsa_hw_port {
--
2.25.1
Ok, now the problem.
This works, except when the master is another DSA switch.
You see, I hit this -EBUSY condition:
static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
u16 vid)
{
...
/* Check for a possible bridge VLAN entry now since there is no
* need to emulate the switchdev prepare + commit phase.
*/
if (dp->bridge_dev) {
...
/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
* device, respectively the VID is not found, returning
* 0 means success, which is a failure for us here.
*/
ret = br_vlan_get_info(dp->bridge_dev, vid, &info);
if (ret == 0)
return -EBUSY;
}
}
Introduced by:
commit 061f6a505ac33659eab007731c0f6374df39ab55
Author: Florian Fainelli <f.faine...@gmail.com>
Date: Wed Feb 20 14:35:39 2019 -0800
net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation
In order to properly support VLAN filtering being enabled/disabled on a
bridge, while having other ports being non bridge port members, we need
to support the ndo_vlan_rx_{add,kill}_vid callbacks in order to make
sure the non-bridge ports can continue receiving VLAN tags, even when
the switch is globally configured to do ingress/egress VID checking.
Since we can call dsa_port_vlan_{add,del} with a bridge_dev pointer
NULL, we now need to check that in these two functions.
We specifically deal with two possibly problematic cases:
- creating a bridge VLAN entry while there is an existing VLAN device
claiming that same VID
- creating a VLAN device while there is an existing bridge VLAN entry
with that VID
Those are both resolved with returning -EBUSY back to user-space.
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Florian, can you please reiterate what is the problem with calling
vlan_vid_add() with a VLAN that is installed by the bridge?
The effect of vlan_vid_add(), to my knowledge, is that the network
interface should add this VLAN to its filtering table, and not drop it.
So why return -EBUSY?
Thanks,
-Vladimir
