[ovs-dev] [PATCH] datapath: Don't drop MTU-sized VLAN packets from userspace

Ben Pfaff blp at nicira.com
Sat Sep 5 04:40:52 UTC 2009

Justin Pettit <jpettit at nicira.com> writes:

> Before transimitting a packet, the datapath checks that the packet
> length is not greater than the MTU.  It determines the length based on
> the 'protocol' field in the skb.  If 'protocol' is ETH_P_8021Q, it reduces
> the packet length as stored in the 'len' field by four bytes, which
> is the size of a VLAN tag header.  Unfortunately, packets that arrived
> from userspace were not having the 'protocol' field set, which would
> cause MTU-sized packets to be dropped.  This commit sets the 'protocol'
> field appropriately.

It looks fine.

Should there be a comment saying that we're doing a subset of
what eth_type_trans() would otherwise do?

Should we do the funny test for Netware packets that
eth_type_trans() does?

More information about the dev mailing list