nat: deal with flows instead of sessions

This change introduces flow concept to endpoint-dependent NAT. Instead
of having a session and a plethora of special cases in code for e.g.
hairpinning, twice-nat and others, figure all this out and store it in
flow logic. Every flow has a match and a rewrite part. This unifies all
the NAT packet processing cases into one - match a flow and rewrite the
packet based on that flow. It also provides a cure for hairpinning
dilemma where one part of the flow is on one worker and another on
a different one. These cases are also sped up by not requiring
destination adress lookup every single time to be able to rewrite source
nat as this is now part of flow rewrite logic.

Type: improvement
Change-Id: Ib60c992e16792ea4d4129bc10202ebb99a73b5be
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/plugins/nat/nat44-ei/nat44_ei_ha.h b/src/plugins/nat/nat44-ei/nat44_ei_ha.h
index c466d4c9288..5639c8d0239 100644
--- a/src/plugins/nat/nat44-ei/nat44_ei_ha.h
+++ b/src/plugins/nat/nat44-ei/nat44_ei_ha.h
@@ -22,6 +22,7 @@
 
 #include <vnet/vnet.h>
 #include <vnet/ip/ip.h>
+#include <nat/nat.h>
 
 /* Call back functions for received HA events on passive/failover */
 typedef void (*nat_ha_sadd_cb_t) (ip4_address_t * in_addr, u16 in_port,
@@ -30,6 +31,7 @@ typedef void (*nat_ha_sadd_cb_t) (ip4_address_t * in_addr, u16 in_port,
 				  ip4_address_t * ehn_addr, u16 ehn_port,
 				  u8 proto, u32 fib_index, u16 flags,
 				  u32 thread_index);
+
 typedef void (*nat_ha_sdel_cb_t) (ip4_address_t * out_addr, u16 out_port,
 				  ip4_address_t * eh_addr, u16 eh_port,
 				  u8 proto, u32 fib_index, u32 thread_index);