[ovs-dev] [bisected] every IP fragment now goes to userspace

[Jesse Gross]

On Wed, Jun 8, 2011 at 10:51 AM, Ben Pfaff <blp at nicira.com> wrote:
> I accidentally discovered that on "master" every IP fragment ends up
> being sent to userspace.  My test case is "netperf -H 192.168.0.2 -t
> UDP_STREAM" (which generates 64 kB UDP packets), then observing that
> the datapath "miss" counter goes up quickly while the "hit" counter
> stays put, as well as noticing that the packet counter for the UDP
> datapath flow stays stuck at 0.

Thanks, good catch.  In flow_extract() we currently act as if there is
no L4 header at all if the packet is a fragment, however, we should
match against a set of zeroed fields instead of effectively
wildcarding them.

I write a patch for this in a little bit.