openvswitch: Allow attaching helpers to ct action

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

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Joe Stringer 2015-08-26 11:31:53 -07:00 committed by David S. Miller
parent c2ac667358
commit cae3a26275
2 changed files with 110 additions and 2 deletions

View file

@ -626,6 +626,7 @@ struct ovs_action_hash {
* @OVS_CT_ATTR_LABEL: %OVS_CT_LABEL_LEN value followed by %OVS_CT_LABEL_LEN
* mask. For each bit set in the mask, the corresponding bit in the value is
* copied to the connection tracking label field in the connection.
* @OVS_CT_ATTR_HELPER: variable length string defining conntrack ALG.
*/
enum ovs_ct_attr {
OVS_CT_ATTR_UNSPEC,
@ -633,6 +634,8 @@ enum ovs_ct_attr {
OVS_CT_ATTR_ZONE, /* u16 zone id. */
OVS_CT_ATTR_MARK, /* mark to associate with this connection. */
OVS_CT_ATTR_LABEL, /* label to associate with this connection. */
OVS_CT_ATTR_HELPER, /* netlink helper to assist detection of
related connections. */
__OVS_CT_ATTR_MAX
};