Re: [PATCHv6 net-next 05/10] openvswitch: Add conntrack action

From: Joe Stringer
Date: Wed Aug 26 2015 - 14:56:21 EST

On 26 August 2015 at 11:31, Joe Stringer <joestringer@xxxxxxxxxx> wrote:
> Expose the kernel connection tracker via OVS. Userspace components can
> make use of the CT action to populate the connection state (ct_state)
> field for a flow. This state can be subsequently matched.
> Exposed connection states are OVS_CS_F_*:
> - NEW (0x01) - Beginning of a new connection.
> - ESTABLISHED (0x02) - Part of an existing connection.
> - RELATED (0x04) - Related to an established connection.
> - INVALID (0x20) - Could not track the connection for this packet.
> - REPLY_DIR (0x40) - This packet is in the reply direction for the flow.
> - TRACKED (0x80) - This packet has been sent through conntrack.
> When the CT action is executed by itself, it will send the packet
> through the connection tracker and populate the ct_state field with one
> or more of the connection state flags above. The CT action will always
> set the TRACKED bit.
> When the COMMIT flag is passed to the conntrack action, this specifies
> that information about the connection should be stored. This allows
> subsequent packets for the same (or related) connections to be
> correlated with this connection. Sending subsequent packets for the
> connection through conntrack allows the connection tracker to consider
> the packets as ESTABLISHED, RELATED, and/or REPLY_DIR.
> The CT action may optionally take a zone to track the flow within. This
> allows connections with the same 5-tuple to be kept logically separate
> from connections in other zones. If the zone is specified, then the
> "ct_zone" match field will be subsequently populated with the zone id.
> IP fragments are handled by transparently assembling them as part of the
> CT action. The maximum received unit (MRU) size is tracked so that
> refragmentation can occur during output.
> IP frag handling contributed by Andy Zhou.

Based on original design by Justin Pettit.

> Signed-off-by: Joe Stringer <joestringer@xxxxxxxxxx>
> Signed-off-by: Justin Pettit <jpettit@xxxxxxxxxx>
> Signed-off-by: Andy Zhou <azhou@xxxxxxxxxx>
> Acked-by: Thomas Graf <tgraf@xxxxxxx>
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