On 02/01/2013 08:15 PM, Michał Mirosław wrote:
2013/2/2 Michał Mirosław <mirqus@xxxxxxxxx>:
2013/2/1 Vlad Yasevich <vyasevic@xxxxxxxxxx>:
A user may designate a certain vlan as PVID. This means that
any ingress frame that does not contain a vlan tag is assigned to
this vlan and any forwarding decisions are made with this vlan in mind.
[...]
struct net_port_vlans {
u16 port_idx;
+ u16 pvid;
I'm confused about the implementation. I would expect pvid field in
net_bridge_port and adding a tag if it isn't there on ingress path.
The rest would be just like without PVIDs. But here you pvid field to
net_port_vlans, and don't do anything with it in receive nor transmit
path. Does it work? What am I missing?
Found the answer in next patch (you should merge #5 and #6).
It was split for incremental testing. #5 added the ability to set and
delete it without impacting anything. #6 added the actual work that
pvid does.
Still,
the implementation looks overly complicated. If you force the packet
to canonical form on ingress (keeping outer tag in skb->vlan_tci, and
setting skb->vlan_tci = pvid if there is no tag) the code should get
simpler.
What if there is no outer tag? That's what the ingress code is doing.
If there is no outer tag, pvid is written to vlan_tci. If there was
outer tag in vlan_tci, it's left alone. This way at the end of ingress
vlan_tci is always set.
At egress, we grab that tag and compare it against pvid if any. If it
matches, it's stripped. If it doesn't, we output with the tag thus
adding the header.
The only thing I can simplify is grab the tci directly at egress, but
that's what the code will do anyway.
-vlad
Best Regards,
Michał Mirosław
