Subject: Re: [PATCH net-next 1/2] openvswitch: add tunnel protocol to sw_flow_key

From: Jiri Benc <[email-masked]>
Date: Wed, 30 Sep 2015 09:09:46 +0200

On Tue, 29 Sep 2015 13:41:34 -0700, Pravin Shelar wrote:
> We can add rather add TUNNEL_IPV6 flag to distinguish IPv4 and IPv6
> tunnel keys. This can be stored in ip_tunnel_key.tun_flags.

Not really. This was my original approach, too, but openvswitch is not
the only user of struct ip_tunnel_key, and in the lwtunnel core,
tun_flags are handled in the way that makes this impractical. Most
importantly, the tun_flags value is directly taken from/stored to
LWTUNNEL_IP_FLAGS/LWTUNNEL_IP6_FLAGS netlink attributes in
net/ipv4/ip_tunnel_core.c. This would mean complicated masking, etc.

> That also saves space in flow key.

The field was added to a 2 byte hole in the struct sw_flow_key (leaving
still 1 byte free), thus there's no additional space used.

 Jiri

-- 
Jiri Benc