openvswitch: kernel datapath clone action

Add 'clone' action to kernel datapath by using existing functions.
When actions within clone don't modify the current flow, the flow
key is not cloned before executing clone actions.

This is a follow up patch for this incomplete work:
https://patchwork.ozlabs.org/patch/722096/

v1 -> v2:
Refactor as advised by reviewer.

Signed-off-by: Yifeng Sun <pkusunyifeng@gmail.com>
Signed-off-by: Andy Zhou <azhou@ovn.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/openvswitch.h b/include/linux/openvswitch.h
index e6b240b6196c..379affc63e24 100644
--- a/include/linux/openvswitch.h
+++ b/include/linux/openvswitch.h
@@ -21,4 +21,9 @@
 
 #include <uapi/linux/openvswitch.h>
 
+#define OVS_CLONE_ATTR_EXEC      0   /* Specify an u32 value. When nonzero,
+                                      * actions in clone will not change flow
+                                      * keys. False otherwise.
+                                      */
+
 #endif /* _LINUX_OPENVSWITCH_H */
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 863aabaa5cc9..dbe0cbe4f1b7 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -840,6 +840,8 @@ struct ovs_action_push_eth {
  * @OVS_ACTION_ATTR_POP_NSH: pop the outermost NSH header off the packet.
  * @OVS_ACTION_ATTR_METER: Run packet through a meter, which may drop the
  * packet, or modify the packet (e.g., change the DSCP field).
+ * @OVS_ACTION_ATTR_CLONE: make a copy of the packet and execute a list of
+ * actions without affecting the original packet and key.
  *
  * Only a single header can be set with a single %OVS_ACTION_ATTR_SET.  Not all
  * fields within a header are modifiable, e.g. the IPv4 protocol and fragment
@@ -873,6 +875,7 @@ enum ovs_action_attr {
         OVS_ACTION_ATTR_PUSH_NSH,     /* Nested OVS_NSH_KEY_ATTR_*. */
         OVS_ACTION_ATTR_POP_NSH,      /* No argument. */
         OVS_ACTION_ATTR_METER,        /* u32 meter ID. */
+        OVS_ACTION_ATTR_CLONE,        /* Nested OVS_CLONE_ATTR_*.  */
 
         __OVS_ACTION_ATTR_MAX,        /* Nothing past this will be accepted
                                        * from userspace. */