Re: [PATCHv5 net-next 10/10] openvswitch: Allow attaching helpers to ct action

On 08/24/15 at 05:32pm, Joe Stringer wrote:

Add support for using conntrack helpers to assist protocol detection.
The new OVS_CT_ATTR_HELPER attribute of the CT action specifies a helper
to be used for this connection. If no helper is specified, then helpers
will be automatically applied as per the sysctl configuration of
net.netfilter.nf_conntrack_helper.

The helper may be specified as part of the conntrack action, eg:
ct(helper=ftp). Initial packets for related connections should be
committed to allow later packets for the flow to be considered
established.

Example ovs-ofctl flows allowing FTP connections from ports 1->2:
in_port=1,tcp,action=ct(helper=ftp,commit),2
in_port=2,tcp,ct_state=-trk,action=ct(recirc)
in_port=2,tcp,ct_state=+trk-new+est,action=1
in_port=2,tcp,ct_state=+trk+rel,action=1

Not subject to this patch but we may want to revisit the syntax of the
state flags. It's neatly compressed like this but ct_state=untracked
ct_state=related might be more readable. The +trk should be implicit
for anything !untracked

Signed-off-by: Joe Stringer <redacted>

Acked-by: Thomas Graf <tgraf@suug.ch>