cnat: flag to disable rsession
[vpp.git] / src / plugins / cnat / cnat_node.h
index 2e3b0e0..d81f674 100644 (file)
 #define __CNAT_NODE_H__
 
 #include <vlibmemory/api.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/load_balance_map.h>
+#include <vnet/ip/ip_psh_cksum.h>
+
 #include <cnat/cnat_session.h>
 #include <cnat/cnat_client.h>
+#include <cnat/cnat_inline.h>
+#include <cnat/cnat_translation.h>
+
+#include <vnet/ip/ip4_inlines.h>
+#include <vnet/ip/ip6_inlines.h>
 
 typedef uword (*cnat_node_sub_t) (vlib_main_t * vm,
                                  vlib_node_runtime_t * node,
@@ -26,6 +35,77 @@ typedef uword (*cnat_node_sub_t) (vlib_main_t * vm,
                                  cnat_node_ctx_t * ctx, int rv,
                                  cnat_session_t * session);
 
+typedef struct cnat_trace_element_t_
+{
+  cnat_session_t session;
+  cnat_translation_t tr;
+  u32 sw_if_index[VLIB_N_RX_TX];
+  u32 snat_policy_result;
+  u8 flags;
+} cnat_trace_element_t;
+
+typedef enum cnat_trace_element_flag_t_
+{
+  CNAT_TRACE_SESSION_FOUND = (1 << 0),
+  CNAT_TRACE_SESSION_CREATED = (1 << 1),
+  CNAT_TRACE_TRANSLATION_FOUND = (1 << 2),
+  CNAT_TRACE_NO_NAT = (1 << 3),
+} cnat_trace_element_flag_t;
+
+static_always_inline void
+cnat_add_trace (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_buffer_t *b,
+               cnat_session_t *session, const cnat_translation_t *ct,
+               u8 flags)
+{
+  cnat_trace_element_t *t;
+  if (NULL != ct)
+    flags |= CNAT_TRACE_TRANSLATION_FOUND;
+
+  t = vlib_add_trace (vm, node, b, sizeof (*t));
+  t->sw_if_index[VLIB_RX] = vnet_buffer (b)->sw_if_index[VLIB_RX];
+  t->sw_if_index[VLIB_TX] = vnet_buffer (b)->sw_if_index[VLIB_TX];
+
+  if (flags & (CNAT_TRACE_SESSION_FOUND | CNAT_TRACE_SESSION_CREATED))
+    clib_memcpy (&t->session, session, sizeof (t->session));
+  if (flags & CNAT_TRACE_TRANSLATION_FOUND)
+    clib_memcpy (&t->tr, ct, sizeof (cnat_translation_t));
+  t->flags = flags;
+}
+
+static u8 *
+format_cnat_trace (u8 *s, va_list *args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  cnat_trace_element_t *t = va_arg (*args, cnat_trace_element_t *);
+  u32 indent = format_get_indent (s);
+  vnet_main_t *vnm = vnet_get_main ();
+
+  if (t->flags & CNAT_TRACE_SESSION_CREATED)
+    s = format (s, "created session");
+  else if (t->flags & CNAT_TRACE_SESSION_FOUND)
+    s = format (s, "found session");
+  else
+    s = format (s, "session not found");
+
+  if (t->flags & (CNAT_TRACE_NO_NAT))
+    s = format (s, " [policy:skip]");
+
+  s = format (s, "\n%Uin:%U out:%U ", format_white_space, indent,
+             format_vnet_sw_if_index_name, vnm, t->sw_if_index[VLIB_RX],
+             format_vnet_sw_if_index_name, vnm, t->sw_if_index[VLIB_TX]);
+
+  if (t->flags & (CNAT_TRACE_SESSION_CREATED | CNAT_TRACE_SESSION_FOUND))
+    s = format (s, "\n%U%U", format_white_space, indent, format_cnat_session,
+               &t->session, 1);
+
+  if (t->flags & CNAT_TRACE_TRANSLATION_FOUND)
+    s = format (s, "\n%Utranslation: %U", format_white_space, indent,
+               format_cnat_translation, &t->tr, 0);
+
+  return s;
+}
+
 static_always_inline u8
 icmp_type_is_error_message (u8 icmp_type)
 {
@@ -90,86 +170,92 @@ cmp_ip6_address (const ip6_address_t * a1, const ip6_address_t * a2)
  * Inline translation functions
  */
 
-static_always_inline u8
-has_ip6_address (ip6_address_t * a)
+static_always_inline u16
+ip4_pseudo_header_cksum2 (ip4_header_t *ip4, ip4_address_t address[VLIB_N_DIR])
 {
-  return ((0 != a->as_u64[0]) || (0 != a->as_u64[1]));
+  ip4_psh_t psh = { 0 };
+  psh.src = address[VLIB_RX];
+  psh.dst = address[VLIB_TX];
+  psh.proto = ip4->protocol;
+  psh.l4len = clib_host_to_net_u16 (clib_net_to_host_u16 (ip4->length) -
+                                   sizeof (ip4_header_t));
+  return ~(clib_ip_csum ((u8 *) &psh, sizeof (ip4_psh_t)));
 }
 
 static_always_inline void
-cnat_ip4_translate_l4 (ip4_header_t * ip4, udp_header_t * udp,
-                      ip_csum_t * sum,
+cnat_ip4_translate_l4 (ip4_header_t *ip4, udp_header_t *udp, ip_csum_t *sum,
                       ip4_address_t new_addr[VLIB_N_DIR],
-                      u16 new_port[VLIB_N_DIR])
+                      u16 new_port[VLIB_N_DIR], u32 oflags)
 {
   u16 old_port[VLIB_N_DIR];
-  ip4_address_t old_addr[VLIB_N_DIR];
+  old_port[VLIB_TX] = udp->dst_port;
+  old_port[VLIB_RX] = udp->src_port;
 
-  /* Fastpath no checksum */
-  if (PREDICT_TRUE (0 == *sum))
+  udp->dst_port = new_port[VLIB_TX];
+  udp->src_port = new_port[VLIB_RX];
+
+  if (oflags &
+      (VNET_BUFFER_OFFLOAD_F_TCP_CKSUM | VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
     {
-      udp->dst_port = new_port[VLIB_TX];
-      udp->src_port = new_port[VLIB_RX];
+      *sum = ip4_pseudo_header_cksum2 (ip4, new_addr);
       return;
     }
 
-  old_port[VLIB_TX] = udp->dst_port;
-  old_port[VLIB_RX] = udp->src_port;
-  old_addr[VLIB_TX] = ip4->dst_address;
-  old_addr[VLIB_RX] = ip4->src_address;
+  *sum = ip_csum_update (*sum, ip4->dst_address.as_u32,
+                        new_addr[VLIB_TX].as_u32, ip4_header_t, dst_address);
+  *sum = ip_csum_update (*sum, ip4->src_address.as_u32,
+                        new_addr[VLIB_RX].as_u32, ip4_header_t, src_address);
+
+  *sum = ip_csum_update (*sum, old_port[VLIB_TX], new_port[VLIB_TX],
+                        udp_header_t, dst_port);
+  *sum = ip_csum_update (*sum, old_port[VLIB_RX], new_port[VLIB_RX],
+                        udp_header_t, src_port);
+}
 
-  if (new_addr[VLIB_TX].as_u32)
+static_always_inline void
+cnat_ip4_translate_sctp (ip4_header_t *ip4, sctp_header_t *sctp,
+                        u16 new_port[VLIB_N_DIR])
+{
+  /* Fastpath no checksum */
+  if (PREDICT_TRUE (0 == sctp->checksum))
     {
-      *sum =
-       ip_csum_update (*sum, old_addr[VLIB_TX].as_u32,
-                       new_addr[VLIB_TX].as_u32, ip4_header_t, dst_address);
+      sctp->dst_port = new_port[VLIB_TX];
+      sctp->src_port = new_port[VLIB_RX];
+      return;
     }
+
   if (new_port[VLIB_TX])
-    {
-      udp->dst_port = new_port[VLIB_TX];
-      *sum = ip_csum_update (*sum, old_port[VLIB_TX], new_port[VLIB_TX],
-                            ip4_header_t /* cheat */ ,
-                            length /* changed member */ );
-    }
-  if (new_addr[VLIB_RX].as_u32)
-    {
-      *sum =
-       ip_csum_update (*sum, old_addr[VLIB_RX].as_u32,
-                       new_addr[VLIB_RX].as_u32, ip4_header_t, src_address);
-    }
+    sctp->dst_port = new_port[VLIB_TX];
   if (new_port[VLIB_RX])
-    {
-      udp->src_port = new_port[VLIB_RX];
-      *sum = ip_csum_update (*sum, old_port[VLIB_RX], new_port[VLIB_RX],
-                            ip4_header_t /* cheat */ ,
-                            length /* changed member */ );
-    }
+    sctp->src_port = new_port[VLIB_RX];
+
+  sctp->checksum = 0;
+  sctp->checksum = clib_host_to_little_u32 (~clib_crc32c_with_init (
+    (u8 *) sctp, ntohs (ip4->length) - sizeof (ip4_header_t),
+    ~0 /* init value */));
 }
 
 static_always_inline void
-cnat_ip4_translate_l3 (ip4_header_t * ip4, ip4_address_t new_addr[VLIB_N_DIR])
+cnat_ip4_translate_l3 (ip4_header_t *ip4, ip4_address_t new_addr[VLIB_N_DIR],
+                      u32 oflags)
 {
   ip4_address_t old_addr[VLIB_N_DIR];
   ip_csum_t sum;
-
   old_addr[VLIB_TX] = ip4->dst_address;
   old_addr[VLIB_RX] = ip4->src_address;
 
+  ip4->dst_address = new_addr[VLIB_TX];
+  ip4->src_address = new_addr[VLIB_RX];
+
+  // We always compute the IP checksum even if oflags &
+  // VNET_BUFFER_OFFLOAD_F_IP_CKSUM is set as this is relatively inexpensive
+  // and will allow avoiding issues in driver that do not behave properly
+  // downstream.
   sum = ip4->checksum;
-  if (new_addr[VLIB_TX].as_u32)
-    {
-      ip4->dst_address = new_addr[VLIB_TX];
-      sum =
-       ip_csum_update (sum, old_addr[VLIB_TX].as_u32,
+  sum = ip_csum_update (sum, old_addr[VLIB_TX].as_u32,
                        new_addr[VLIB_TX].as_u32, ip4_header_t, dst_address);
-    }
-  if (new_addr[VLIB_RX].as_u32)
-    {
-      ip4->src_address = new_addr[VLIB_RX];
-      sum =
-       ip_csum_update (sum, old_addr[VLIB_RX].as_u32,
+  sum = ip_csum_update (sum, old_addr[VLIB_RX].as_u32,
                        new_addr[VLIB_RX].as_u32, ip4_header_t, src_address);
-    }
   ip4->checksum = ip_csum_fold (sum);
 }
 
@@ -178,48 +264,40 @@ cnat_tcp_update_session_lifetime (tcp_header_t * tcp, u32 index)
 {
   cnat_main_t *cm = &cnat_main;
   if (PREDICT_FALSE (tcp_fin (tcp)))
-    {
-      cnat_timestamp_set_lifetime (index, CNAT_DEFAULT_TCP_RST_TIMEOUT);
-    }
+    cnat_timestamp_set_lifetime (index, CNAT_DEFAULT_TCP_RST_TIMEOUT);
 
   if (PREDICT_FALSE (tcp_rst (tcp)))
-    {
-      cnat_timestamp_set_lifetime (index, CNAT_DEFAULT_TCP_RST_TIMEOUT);
-    }
+    cnat_timestamp_set_lifetime (index, CNAT_DEFAULT_TCP_RST_TIMEOUT);
 
   if (PREDICT_FALSE (tcp_syn (tcp) && tcp_ack (tcp)))
-    {
-      cnat_timestamp_set_lifetime (index, cm->tcp_max_age);
-    }
+    cnat_timestamp_set_lifetime (index, cm->tcp_max_age);
 }
 
 static_always_inline void
-cnat_translation_icmp4_echo (ip4_header_t * ip4, icmp46_header_t * icmp,
+cnat_translation_icmp4_echo (ip4_header_t *ip4, icmp46_header_t *icmp,
                             ip4_address_t new_addr[VLIB_N_DIR],
-                            u16 new_port[VLIB_N_DIR])
+                            u16 new_port[VLIB_N_DIR], u32 oflags)
 {
   ip_csum_t sum;
   u16 old_port;
   cnat_echo_header_t *echo = (cnat_echo_header_t *) (icmp + 1);
 
-  cnat_ip4_translate_l3 (ip4, new_addr);
+  cnat_ip4_translate_l3 (ip4, new_addr, oflags);
   old_port = echo->identifier;
   echo->identifier = new_port[VLIB_RX];
 
   sum = icmp->checksum;
-  sum = ip_csum_update (sum, old_port, new_port[VLIB_RX],
-                       ip4_header_t /* cheat */ ,
-                       length /* changed member */ );
+  sum =
+    ip_csum_update (sum, old_port, new_port[VLIB_RX], udp_header_t, src_port);
 
   icmp->checksum = ip_csum_fold (sum);
 }
 
 static_always_inline void
-cnat_translation_icmp4_error (ip4_header_t * outer_ip4,
-                             icmp46_header_t * icmp,
+cnat_translation_icmp4_error (ip4_header_t *outer_ip4, icmp46_header_t *icmp,
                              ip4_address_t outer_new_addr[VLIB_N_DIR],
-                             u16 outer_new_port[VLIB_N_DIR],
-                             u8 snat_outer_ip)
+                             u16 outer_new_port[VLIB_N_DIR], u8 snat_outer_ip,
+                             u32 oflags)
 {
   ip4_address_t new_addr[VLIB_N_DIR];
   ip4_address_t old_addr[VLIB_N_DIR];
@@ -248,18 +326,20 @@ cnat_translation_icmp4_error (ip4_header_t * outer_ip4,
   /* translate outer ip. */
   if (!snat_outer_ip)
     outer_new_addr[VLIB_RX] = outer_ip4->src_address;
-  cnat_ip4_translate_l3 (outer_ip4, outer_new_addr);
+  cnat_ip4_translate_l3 (outer_ip4, outer_new_addr, oflags);
 
   if (ip4->protocol == IP_PROTOCOL_TCP)
     {
       inner_l4_old_sum = inner_l4_sum = tcp->checksum;
-      cnat_ip4_translate_l4 (ip4, udp, &inner_l4_sum, new_addr, new_port);
+      cnat_ip4_translate_l4 (ip4, udp, &inner_l4_sum, new_addr, new_port,
+                            0 /* flags */);
       tcp->checksum = ip_csum_fold (inner_l4_sum);
     }
   else if (ip4->protocol == IP_PROTOCOL_UDP)
     {
       inner_l4_old_sum = inner_l4_sum = udp->checksum;
-      cnat_ip4_translate_l4 (ip4, udp, &inner_l4_sum, new_addr, new_port);
+      cnat_ip4_translate_l4 (ip4, udp, &inner_l4_sum, new_addr, new_port,
+                            0 /* flags */);
       udp->checksum = ip_csum_fold (inner_l4_sum);
     }
   else
@@ -272,37 +352,30 @@ cnat_translation_icmp4_error (ip4_header_t * outer_ip4,
   /* UDP/TCP Ports changed */
   if (old_port[VLIB_TX] && new_port[VLIB_TX])
     sum = ip_csum_update (sum, old_port[VLIB_TX], new_port[VLIB_TX],
-                         ip4_header_t /* cheat */ ,
-                         length /* changed member */ );
+                         udp_header_t, dst_port);
 
   if (old_port[VLIB_RX] && new_port[VLIB_RX])
     sum = ip_csum_update (sum, old_port[VLIB_RX], new_port[VLIB_RX],
-                         ip4_header_t /* cheat */ ,
-                         length /* changed member */ );
-
+                         udp_header_t, src_port);
 
-  cnat_ip4_translate_l3 (ip4, new_addr);
+  cnat_ip4_translate_l3 (ip4, new_addr, 0 /* oflags */);
   ip_csum_t new_ip_sum = ip4->checksum;
   /* IP checksum changed */
   sum = ip_csum_update (sum, old_ip_sum, new_ip_sum, ip4_header_t, checksum);
 
   /* IP src/dst addr changed */
-  if (new_addr[VLIB_TX].as_u32)
-    sum =
-      ip_csum_update (sum, old_addr[VLIB_TX].as_u32, new_addr[VLIB_TX].as_u32,
-                     ip4_header_t, dst_address);
+  sum = ip_csum_update (sum, old_addr[VLIB_TX].as_u32,
+                       new_addr[VLIB_TX].as_u32, ip4_header_t, dst_address);
 
-  if (new_addr[VLIB_RX].as_u32)
-    sum =
-      ip_csum_update (sum, old_addr[VLIB_RX].as_u32, new_addr[VLIB_RX].as_u32,
-                     ip4_header_t, src_address);
+  sum = ip_csum_update (sum, old_addr[VLIB_RX].as_u32,
+                       new_addr[VLIB_RX].as_u32, ip4_header_t, src_address);
 
   icmp->checksum = ip_csum_fold (sum);
 }
 
 static_always_inline void
-cnat_translation_ip4 (const cnat_session_t * session,
-                     ip4_header_t * ip4, udp_header_t * udp)
+cnat_translation_ip4 (const cnat_session_t *session, ip4_header_t *ip4,
+                     udp_header_t *udp, u32 oflags)
 {
   tcp_header_t *tcp = (tcp_header_t *) udp;
   ip4_address_t new_addr[VLIB_N_DIR];
@@ -316,17 +389,23 @@ cnat_translation_ip4 (const cnat_session_t * session,
   if (ip4->protocol == IP_PROTOCOL_TCP)
     {
       ip_csum_t sum = tcp->checksum;
-      cnat_ip4_translate_l4 (ip4, udp, &sum, new_addr, new_port);
+      cnat_ip4_translate_l4 (ip4, udp, &sum, new_addr, new_port, oflags);
       tcp->checksum = ip_csum_fold (sum);
-      cnat_ip4_translate_l3 (ip4, new_addr);
+      cnat_ip4_translate_l3 (ip4, new_addr, oflags);
       cnat_tcp_update_session_lifetime (tcp, session->value.cs_ts_index);
     }
   else if (ip4->protocol == IP_PROTOCOL_UDP)
     {
       ip_csum_t sum = udp->checksum;
-      cnat_ip4_translate_l4 (ip4, udp, &sum, new_addr, new_port);
+      cnat_ip4_translate_l4 (ip4, udp, &sum, new_addr, new_port, oflags);
       udp->checksum = ip_csum_fold (sum);
-      cnat_ip4_translate_l3 (ip4, new_addr);
+      cnat_ip4_translate_l3 (ip4, new_addr, oflags);
+    }
+  else if (ip4->protocol == IP_PROTOCOL_SCTP)
+    {
+      sctp_header_t *sctp = (sctp_header_t *) udp;
+      cnat_ip4_translate_sctp (ip4, sctp, new_port);
+      cnat_ip4_translate_l3 (ip4, new_addr, oflags);
     }
   else if (ip4->protocol == IP_PROTOCOL_ICMP)
     {
@@ -338,74 +417,65 @@ cnat_translation_ip4 (const cnat_session_t * session,
            (ip4->src_address.as_u32 ==
             session->key.cs_ip[VLIB_RX].ip4.as_u32);
          cnat_translation_icmp4_error (ip4, icmp, new_addr, new_port,
-                                       snat_outer_ip);
+                                       snat_outer_ip, oflags);
        }
       else if (icmp_type_is_echo (icmp->type))
-       cnat_translation_icmp4_echo (ip4, icmp, new_addr, new_port);
+       cnat_translation_icmp4_echo (ip4, icmp, new_addr, new_port, oflags);
     }
 }
 
 static_always_inline void
 cnat_ip6_translate_l3 (ip6_header_t * ip6, ip6_address_t new_addr[VLIB_N_DIR])
 {
-  if (has_ip6_address (&new_addr[VLIB_TX]))
-    ip6_address_copy (&ip6->dst_address, &new_addr[VLIB_TX]);
-  if (has_ip6_address (&new_addr[VLIB_RX]))
-    ip6_address_copy (&ip6->src_address, &new_addr[VLIB_RX]);
+  ip6_address_copy (&ip6->dst_address, &new_addr[VLIB_TX]);
+  ip6_address_copy (&ip6->src_address, &new_addr[VLIB_RX]);
+}
+
+static_always_inline u16
+ip6_pseudo_header_cksum2 (ip6_header_t *ip6, ip6_address_t address[VLIB_N_DIR])
+{
+  ip6_psh_t psh = { 0 };
+  psh.src = address[VLIB_RX];
+  psh.dst = address[VLIB_TX];
+  psh.l4len = ip6->payload_length;
+  psh.proto = clib_host_to_net_u32 ((u32) ip6->protocol);
+  return ~(clib_ip_csum ((u8 *) &psh, sizeof (ip6_psh_t)));
 }
 
 static_always_inline void
-cnat_ip6_translate_l4 (ip6_header_t * ip6, udp_header_t * udp,
-                      ip_csum_t * sum,
+cnat_ip6_translate_l4 (ip6_header_t *ip6, udp_header_t *udp, ip_csum_t *sum,
                       ip6_address_t new_addr[VLIB_N_DIR],
-                      u16 new_port[VLIB_N_DIR])
+                      u16 new_port[VLIB_N_DIR], u32 oflags)
 {
   u16 old_port[VLIB_N_DIR];
-  ip6_address_t old_addr[VLIB_N_DIR];
+  old_port[VLIB_TX] = udp->dst_port;
+  old_port[VLIB_RX] = udp->src_port;
 
-  /* Fastpath no checksum */
-  if (PREDICT_TRUE (0 == *sum))
+  udp->dst_port = new_port[VLIB_TX];
+  udp->src_port = new_port[VLIB_RX];
+
+  if (oflags &
+      (VNET_BUFFER_OFFLOAD_F_TCP_CKSUM | VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
     {
-      udp->dst_port = new_port[VLIB_TX];
-      udp->src_port = new_port[VLIB_RX];
+      *sum = ip6_pseudo_header_cksum2 (ip6, new_addr);
       return;
     }
 
-  old_port[VLIB_TX] = udp->dst_port;
-  old_port[VLIB_RX] = udp->src_port;
-  ip6_address_copy (&old_addr[VLIB_TX], &ip6->dst_address);
-  ip6_address_copy (&old_addr[VLIB_RX], &ip6->src_address);
+  *sum = ip_csum_add_even (*sum, new_addr[VLIB_TX].as_u64[0]);
+  *sum = ip_csum_add_even (*sum, new_addr[VLIB_TX].as_u64[1]);
+  *sum = ip_csum_sub_even (*sum, ip6->dst_address.as_u64[0]);
+  *sum = ip_csum_sub_even (*sum, ip6->dst_address.as_u64[1]);
 
-  if (has_ip6_address (&new_addr[VLIB_TX]))
-    {
-      *sum = ip_csum_add_even (*sum, new_addr[VLIB_TX].as_u64[0]);
-      *sum = ip_csum_add_even (*sum, new_addr[VLIB_TX].as_u64[1]);
-      *sum = ip_csum_sub_even (*sum, old_addr[VLIB_TX].as_u64[0]);
-      *sum = ip_csum_sub_even (*sum, old_addr[VLIB_TX].as_u64[1]);
-    }
+  *sum = ip_csum_add_even (*sum, new_addr[VLIB_RX].as_u64[0]);
+  *sum = ip_csum_add_even (*sum, new_addr[VLIB_RX].as_u64[1]);
+  *sum = ip_csum_sub_even (*sum, ip6->src_address.as_u64[0]);
+  *sum = ip_csum_sub_even (*sum, ip6->src_address.as_u64[1]);
 
-  if (new_port[VLIB_TX])
-    {
-      udp->dst_port = new_port[VLIB_TX];
-      *sum = ip_csum_update (*sum, old_port[VLIB_TX], new_port[VLIB_TX],
-                            ip4_header_t /* cheat */ ,
-                            length /* changed member */ );
-    }
-  if (has_ip6_address (&new_addr[VLIB_RX]))
-    {
-      *sum = ip_csum_add_even (*sum, new_addr[VLIB_RX].as_u64[0]);
-      *sum = ip_csum_add_even (*sum, new_addr[VLIB_RX].as_u64[1]);
-      *sum = ip_csum_sub_even (*sum, old_addr[VLIB_RX].as_u64[0]);
-      *sum = ip_csum_sub_even (*sum, old_addr[VLIB_RX].as_u64[1]);
-    }
+  *sum = ip_csum_update (*sum, old_port[VLIB_TX], new_port[VLIB_TX],
+                        udp_header_t, dst_port);
 
-  if (new_port[VLIB_RX])
-    {
-      udp->src_port = new_port[VLIB_RX];
-      *sum = ip_csum_update (*sum, old_port[VLIB_RX], new_port[VLIB_RX],
-                            ip4_header_t /* cheat */ ,
-                            length /* changed member */ );
-    }
+  *sum = ip_csum_update (*sum, old_port[VLIB_RX], new_port[VLIB_RX],
+                        udp_header_t, src_port);
 }
 
 static_always_inline void
@@ -424,26 +494,20 @@ cnat_translation_icmp6_echo (ip6_header_t * ip6, icmp46_header_t * icmp,
   sum = icmp->checksum;
 
   cnat_ip6_translate_l3 (ip6, new_addr);
-  if (has_ip6_address (&new_addr[VLIB_TX]))
-    {
-      sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[0]);
-      sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[1]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[0]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[1]);
-    }
 
-  if (has_ip6_address (&new_addr[VLIB_RX]))
-    {
-      sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[0]);
-      sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[1]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[0]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[1]);
-    }
+  sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[0]);
+  sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[1]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[0]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[1]);
+
+  sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[0]);
+  sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[1]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[0]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[1]);
 
   echo->identifier = new_port[VLIB_RX];
-  sum = ip_csum_update (sum, old_port, new_port[VLIB_RX],
-                       ip4_header_t /* cheat */ ,
-                       length /* changed member */ );
+  sum =
+    ip_csum_update (sum, old_port, new_port[VLIB_RX], udp_header_t, src_port);
 
   icmp->checksum = ip_csum_fold (sum);
 }
@@ -487,79 +551,64 @@ cnat_translation_icmp6_error (ip6_header_t * outer_ip6,
   if (!snat_outer_ip)
     ip6_address_copy (&outer_new_addr[VLIB_RX], &outer_ip6->src_address);
   cnat_ip6_translate_l3 (outer_ip6, outer_new_addr);
-  if (has_ip6_address (&outer_new_addr[VLIB_TX]))
-    {
-      sum = ip_csum_add_even (sum, outer_new_addr[VLIB_TX].as_u64[0]);
-      sum = ip_csum_add_even (sum, outer_new_addr[VLIB_TX].as_u64[1]);
-      sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_TX].as_u64[0]);
-      sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_TX].as_u64[1]);
-    }
 
-  if (has_ip6_address (&outer_new_addr[VLIB_RX]))
-    {
-      sum = ip_csum_add_even (sum, outer_new_addr[VLIB_RX].as_u64[0]);
-      sum = ip_csum_add_even (sum, outer_new_addr[VLIB_RX].as_u64[1]);
-      sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_RX].as_u64[0]);
-      sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_RX].as_u64[1]);
-    }
+  sum = ip_csum_add_even (sum, outer_new_addr[VLIB_TX].as_u64[0]);
+  sum = ip_csum_add_even (sum, outer_new_addr[VLIB_TX].as_u64[1]);
+  sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_TX].as_u64[0]);
+  sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_TX].as_u64[1]);
+
+  sum = ip_csum_add_even (sum, outer_new_addr[VLIB_RX].as_u64[0]);
+  sum = ip_csum_add_even (sum, outer_new_addr[VLIB_RX].as_u64[1]);
+  sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_RX].as_u64[0]);
+  sum = ip_csum_sub_even (sum, outer_old_addr[VLIB_RX].as_u64[1]);
 
   /* Translate inner TCP / UDP */
   if (ip6->protocol == IP_PROTOCOL_TCP)
     {
       inner_l4_old_sum = inner_l4_sum = tcp->checksum;
-      cnat_ip6_translate_l4 (ip6, udp, &inner_l4_sum, new_addr, new_port);
+      cnat_ip6_translate_l4 (ip6, udp, &inner_l4_sum, new_addr, new_port,
+                            0 /* oflags */);
       tcp->checksum = ip_csum_fold (inner_l4_sum);
     }
   else if (ip6->protocol == IP_PROTOCOL_UDP)
     {
       inner_l4_old_sum = inner_l4_sum = udp->checksum;
-      cnat_ip6_translate_l4 (ip6, udp, &inner_l4_sum, new_addr, new_port);
+      cnat_ip6_translate_l4 (ip6, udp, &inner_l4_sum, new_addr, new_port,
+                            0 /* oflags */);
       udp->checksum = ip_csum_fold (inner_l4_sum);
     }
   else
     return;
 
   /* UDP/TCP checksum changed */
-  sum = ip_csum_update (sum, inner_l4_old_sum, inner_l4_sum,
-                       ip4_header_t /* cheat */ ,
+  sum = ip_csum_update (sum, inner_l4_old_sum, inner_l4_sum, ip4_header_t,
                        checksum);
 
   /* UDP/TCP Ports changed */
-  if (old_port[VLIB_TX] && new_port[VLIB_TX])
-    sum = ip_csum_update (sum, old_port[VLIB_TX], new_port[VLIB_TX],
-                         ip4_header_t /* cheat */ ,
-                         length /* changed member */ );
-
-  if (old_port[VLIB_RX] && new_port[VLIB_RX])
-    sum = ip_csum_update (sum, old_port[VLIB_RX], new_port[VLIB_RX],
-                         ip4_header_t /* cheat */ ,
-                         length /* changed member */ );
+  sum = ip_csum_update (sum, old_port[VLIB_TX], new_port[VLIB_TX],
+                       udp_header_t, dst_port);
 
+  sum = ip_csum_update (sum, old_port[VLIB_RX], new_port[VLIB_RX],
+                       udp_header_t, src_port);
 
   cnat_ip6_translate_l3 (ip6, new_addr);
   /* IP src/dst addr changed */
-  if (has_ip6_address (&new_addr[VLIB_TX]))
-    {
-      sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[0]);
-      sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[1]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[0]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[1]);
-    }
+  sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[0]);
+  sum = ip_csum_add_even (sum, new_addr[VLIB_TX].as_u64[1]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[0]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_TX].as_u64[1]);
 
-  if (has_ip6_address (&new_addr[VLIB_RX]))
-    {
-      sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[0]);
-      sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[1]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[0]);
-      sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[1]);
-    }
+  sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[0]);
+  sum = ip_csum_add_even (sum, new_addr[VLIB_RX].as_u64[1]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[0]);
+  sum = ip_csum_sub_even (sum, old_addr[VLIB_RX].as_u64[1]);
 
   icmp->checksum = ip_csum_fold (sum);
 }
 
 static_always_inline void
-cnat_translation_ip6 (const cnat_session_t * session,
-                     ip6_header_t * ip6, udp_header_t * udp)
+cnat_translation_ip6 (const cnat_session_t *session, ip6_header_t *ip6,
+                     udp_header_t *udp, u32 oflags)
 {
   tcp_header_t *tcp = (tcp_header_t *) udp;
   ip6_address_t new_addr[VLIB_N_DIR];
@@ -573,7 +622,7 @@ cnat_translation_ip6 (const cnat_session_t * session,
   if (ip6->protocol == IP_PROTOCOL_TCP)
     {
       ip_csum_t sum = tcp->checksum;
-      cnat_ip6_translate_l4 (ip6, udp, &sum, new_addr, new_port);
+      cnat_ip6_translate_l4 (ip6, udp, &sum, new_addr, new_port, oflags);
       tcp->checksum = ip_csum_fold (sum);
       cnat_ip6_translate_l3 (ip6, new_addr);
       cnat_tcp_update_session_lifetime (tcp, session->value.cs_ts_index);
@@ -581,7 +630,7 @@ cnat_translation_ip6 (const cnat_session_t * session,
   else if (ip6->protocol == IP_PROTOCOL_UDP)
     {
       ip_csum_t sum = udp->checksum;
-      cnat_ip6_translate_l4 (ip6, udp, &sum, new_addr, new_port);
+      cnat_ip6_translate_l4 (ip6, udp, &sum, new_addr, new_port, oflags);
       udp->checksum = ip_csum_fold (sum);
       cnat_ip6_translate_l3 (ip6, new_addr);
     }
@@ -603,18 +652,25 @@ cnat_translation_ip6 (const cnat_session_t * session,
 }
 
 static_always_inline void
-cnat_session_make_key (vlib_buffer_t * b, ip_address_family_t af,
-                      clib_bihash_kv_40_48_t * bkey)
+cnat_session_make_key (vlib_buffer_t *b, ip_address_family_t af,
+                      cnat_session_location_t cs_loc, cnat_bihash_kv_t *bkey)
 {
   udp_header_t *udp;
   cnat_session_t *session = (cnat_session_t *) bkey;
+  u32 iph_offset = 0;
   session->key.cs_af = af;
-  session->key.__cs_pad[0] = 0;
-  session->key.__cs_pad[1] = 0;
+
+  session->key.cs_loc = cs_loc;
+  session->key.__cs_pad = 0;
+  if (cs_loc == CNAT_LOCATION_OUTPUT)
+    /* rewind buffer */
+    iph_offset = vnet_buffer (b)->ip.save_rewrite_length;
+
   if (AF_IP4 == af)
     {
       ip4_header_t *ip4;
-      ip4 = vlib_buffer_get_current (b);
+      ip4 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b) + iph_offset);
+
       if (PREDICT_FALSE (ip4->protocol == IP_PROTOCOL_ICMP))
        {
          icmp46_header_t *icmp = (icmp46_header_t *) (ip4 + 1);
@@ -645,7 +701,8 @@ cnat_session_make_key (vlib_buffer_t * b, ip_address_family_t af,
          else
            goto error;
        }
-      else
+      else if (ip4->protocol == IP_PROTOCOL_UDP ||
+              ip4->protocol == IP_PROTOCOL_TCP)
        {
          udp = (udp_header_t *) (ip4 + 1);
          ip46_address_set_ip4 (&session->key.cs_ip[VLIB_TX],
@@ -656,12 +713,25 @@ cnat_session_make_key (vlib_buffer_t * b, ip_address_family_t af,
          session->key.cs_port[VLIB_RX] = udp->src_port;
          session->key.cs_port[VLIB_TX] = udp->dst_port;
        }
-
+      else if (ip4->protocol == IP_PROTOCOL_SCTP)
+       {
+         sctp_header_t *sctp;
+         sctp = (sctp_header_t *) (ip4 + 1);
+         ip46_address_set_ip4 (&session->key.cs_ip[VLIB_TX],
+                               &ip4->dst_address);
+         ip46_address_set_ip4 (&session->key.cs_ip[VLIB_RX],
+                               &ip4->src_address);
+         session->key.cs_proto = ip4->protocol;
+         session->key.cs_port[VLIB_RX] = sctp->src_port;
+         session->key.cs_port[VLIB_TX] = sctp->dst_port;
+       }
+      else
+       goto error;
     }
   else
     {
       ip6_header_t *ip6;
-      ip6 = vlib_buffer_get_current (b);
+      ip6 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b) + iph_offset);
       if (PREDICT_FALSE (ip6->protocol == IP_PROTOCOL_ICMP6))
        {
          icmp46_header_t *icmp = (icmp46_header_t *) (ip6 + 1);
@@ -692,7 +762,8 @@ cnat_session_make_key (vlib_buffer_t * b, ip_address_family_t af,
          else
            goto error;
        }
-      else
+      else if (ip6->protocol == IP_PROTOCOL_UDP ||
+              ip6->protocol == IP_PROTOCOL_TCP)
        {
          udp = (udp_header_t *) (ip6 + 1);
          ip46_address_set_ip6 (&session->key.cs_ip[VLIB_TX],
@@ -703,6 +774,8 @@ cnat_session_make_key (vlib_buffer_t * b, ip_address_family_t af,
          session->key.cs_port[VLIB_TX] = udp->dst_port;
          session->key.cs_proto = ip6->protocol;
        }
+      else
+       goto error;
     }
   return;
 
@@ -712,117 +785,164 @@ error:
   return;
 }
 
+static_always_inline cnat_ep_trk_t *
+cnat_load_balance (const cnat_translation_t *ct, ip_address_family_t af,
+                  ip4_header_t *ip4, ip6_header_t *ip6, u32 *dpoi_index)
+{
+  cnat_main_t *cm = &cnat_main;
+  const load_balance_t *lb0;
+  const dpo_id_t *dpo0;
+  u32 hash_c0, bucket0;
+
+  lb0 = load_balance_get (ct->ct_lb.dpoi_index);
+  if (PREDICT_FALSE (!lb0->lb_n_buckets))
+    return (NULL);
+
+  /* session table miss */
+  hash_c0 = (AF_IP4 == af ? ip4_compute_flow_hash (ip4, lb0->lb_hash_config) :
+                           ip6_compute_flow_hash (ip6, lb0->lb_hash_config));
+
+  if (PREDICT_FALSE (ct->lb_type == CNAT_LB_MAGLEV))
+    bucket0 = ct->lb_maglev[hash_c0 % cm->maglev_len];
+  else
+    bucket0 = hash_c0 % lb0->lb_n_buckets;
+
+  dpo0 = load_balance_get_fwd_bucket (lb0, bucket0);
+
+  *dpoi_index = dpo0->dpoi_index;
+
+  return &ct->ct_active_paths[bucket0];
+}
+
 /**
  * Create NAT sessions
+ * rsession_location is the location the (return) session will be
+ * matched at
  */
 
 static_always_inline void
-cnat_session_create (cnat_session_t * session, cnat_node_ctx_t * ctx,
-                    u8 rsession_flags)
+cnat_session_create (cnat_session_t *session, cnat_node_ctx_t *ctx)
 {
-  cnat_client_t *cc;
-  clib_bihash_kv_40_48_t rkey;
-  cnat_session_t *rsession = (cnat_session_t *) & rkey;
-  clib_bihash_kv_40_48_t *bkey = (clib_bihash_kv_40_48_t *) session;
-  clib_bihash_kv_40_48_t rvalue;
-  int rv;
+  cnat_bihash_kv_t *bkey = (cnat_bihash_kv_t *) session;
 
   session->value.cs_ts_index = cnat_timestamp_new (ctx->now);
-  clib_bihash_add_del_40_48 (&cnat_session_db, bkey, 1);
-
-  /* is this the first time we've seen this source address */
-  cc = (AF_IP4 == ctx->af ?
-       cnat_client_ip4_find (&session->value.cs_ip[VLIB_RX].ip4) :
-       cnat_client_ip6_find (&session->value.cs_ip[VLIB_RX].ip6));
+  cnat_bihash_add_del (&cnat_session_db, bkey, 1);
+}
 
-  if (NULL == cc)
-    {
-      u64 r0 = 17;
-      if (AF_IP4 == ctx->af)
-       r0 = (u64) session->value.cs_ip[VLIB_RX].ip4.as_u32;
-      else
-       {
-         r0 = r0 * 31 + session->value.cs_ip[VLIB_RX].ip6.as_u64[0];
-         r0 = r0 * 31 + session->value.cs_ip[VLIB_RX].ip6.as_u64[1];
-       }
+static_always_inline void
+cnat_rsession_create (cnat_session_t *session, cnat_node_ctx_t *ctx,
+                     cnat_session_location_t rsession_location,
+                     cnat_session_flag_t rsession_flags)
+{
+  cnat_client_t *cc;
+  cnat_bihash_kv_t rkey;
+  cnat_session_t *rsession = (cnat_session_t *) & rkey;
+  cnat_bihash_kv_t *bkey = (cnat_bihash_kv_t *) session;
+  int rv, n_retries = 0;
+  static u32 sport_seed = 0;
 
-      /* Rate limit */
-      if (!throttle_check (&cnat_throttle, ctx->thread_index, r0, ctx->seed))
-       {
-         cnat_learn_arg_t l;
-         l.addr.version = ctx->af;
-         ip46_address_copy (&l.addr.ip, &session->value.cs_ip[VLIB_RX]);
-         /* fire client create to the main thread */
-         vl_api_rpc_call_main_thread (cnat_client_learn,
-                                      (u8 *) & l, sizeof (l));
-       }
-      else
-       {
-         /* Will still need to count those for session refcnt */
-         ip_address_t *addr;
-         clib_spinlock_lock (&cnat_client_db.throttle_pool_lock
-                             [ctx->thread_index]);
-         pool_get (cnat_client_db.throttle_pool[ctx->thread_index], addr);
-         addr->version = ctx->af;
-         ip46_address_copy (&addr->ip, &session->value.cs_ip[VLIB_RX]);
-         clib_spinlock_unlock (&cnat_client_db.throttle_pool_lock
-                               [ctx->thread_index]);
-       }
-    }
-  else
-    {
-      /* Refcount reverse session */
-      cnat_client_cnt_session (cc);
-    }
+  cnat_timestamp_inc_refcnt (session->value.cs_ts_index);
 
-  /* create the reverse flow key */
+  /* First create the return session */
   ip46_address_copy (&rsession->key.cs_ip[VLIB_RX],
                     &session->value.cs_ip[VLIB_TX]);
   ip46_address_copy (&rsession->key.cs_ip[VLIB_TX],
                     &session->value.cs_ip[VLIB_RX]);
   rsession->key.cs_proto = session->key.cs_proto;
-  rsession->key.__cs_pad[0] = 0;
-  rsession->key.__cs_pad[1] = 0;
+  rsession->key.cs_loc = rsession_location;
+  rsession->key.__cs_pad = 0;
   rsession->key.cs_af = ctx->af;
   rsession->key.cs_port[VLIB_RX] = session->value.cs_port[VLIB_TX];
   rsession->key.cs_port[VLIB_TX] = session->value.cs_port[VLIB_RX];
 
-  /* First search for existing reverse session */
-  rv = clib_bihash_search_inline_2_40_48 (&cnat_session_db, &rkey, &rvalue);
-  if (!rv)
-    {
-      /* Reverse session already exists
-         cleanup before creating for refcnts */
-      cnat_session_t *found_rsession = (cnat_session_t *) & rvalue;
-      cnat_session_free (found_rsession);
-    }
-  /* add the reverse flow */
   ip46_address_copy (&rsession->value.cs_ip[VLIB_RX],
                     &session->key.cs_ip[VLIB_TX]);
   ip46_address_copy (&rsession->value.cs_ip[VLIB_TX],
                     &session->key.cs_ip[VLIB_RX]);
   rsession->value.cs_ts_index = session->value.cs_ts_index;
   rsession->value.cs_lbi = INDEX_INVALID;
-  rsession->value.flags = rsession_flags;
+  rsession->value.flags = rsession_flags | CNAT_SESSION_IS_RETURN;
   rsession->value.cs_port[VLIB_TX] = session->key.cs_port[VLIB_RX];
   rsession->value.cs_port[VLIB_RX] = session->key.cs_port[VLIB_TX];
 
-  clib_bihash_add_del_40_48 (&cnat_session_db, &rkey, 1);
+retry_add_ression:
+  rv = cnat_bihash_add_del (&cnat_session_db, &rkey,
+                           2 /* add but don't overwrite */);
+  if (rv)
+    {
+      if (!(rsession_flags & CNAT_SESSION_RETRY_SNAT))
+       return;
+
+      /* return session add failed pick an new random src port */
+      rsession->value.cs_port[VLIB_TX] = session->key.cs_port[VLIB_RX] =
+       random_u32 (&sport_seed);
+      if (n_retries++ < 100)
+       goto retry_add_ression;
+      else
+       {
+         clib_warning ("Could not find a free port after 100 tries");
+         /* translate this packet, but don't create state */
+         return;
+       }
+    }
+
+  cnat_bihash_add_del (&cnat_session_db, bkey, 1 /* add */);
+
+  if (!(rsession_flags & CNAT_SESSION_FLAG_NO_CLIENT))
+    {
+      /* is this the first time we've seen this source address */
+      cc = (AF_IP4 == ctx->af ?
+             cnat_client_ip4_find (&session->value.cs_ip[VLIB_RX].ip4) :
+             cnat_client_ip6_find (&session->value.cs_ip[VLIB_RX].ip6));
+
+      if (NULL == cc)
+       {
+         ip_address_t addr;
+         uword *p;
+         u32 refcnt;
+
+         addr.version = ctx->af;
+         ip46_address_copy (&addr.ip, &session->value.cs_ip[VLIB_RX]);
+
+         /* Throttle */
+         clib_spinlock_lock (&cnat_client_db.throttle_lock);
+
+         p = hash_get_mem (cnat_client_db.throttle_mem, &addr);
+         if (p)
+           {
+             refcnt = p[0] + 1;
+             hash_set_mem (cnat_client_db.throttle_mem, &addr, refcnt);
+           }
+         else
+           hash_set_mem_alloc (&cnat_client_db.throttle_mem, &addr, 0);
+
+         clib_spinlock_unlock (&cnat_client_db.throttle_lock);
+
+         /* fire client create to the main thread */
+         if (!p)
+           vl_api_rpc_call_main_thread (cnat_client_learn, (u8 *) &addr,
+                                        sizeof (addr));
+       }
+      else
+       {
+         /* Refcount reverse session */
+         cnat_client_cnt_session (cc);
+       }
+    }
+
 }
 
 always_inline uword
-cnat_node_inline (vlib_main_t * vm,
-                 vlib_node_runtime_t * node,
-                 vlib_frame_t * frame,
-                 cnat_node_sub_t cnat_sub,
-                 ip_address_family_t af, u8 do_trace)
+cnat_node_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
+                 vlib_frame_t *frame, cnat_node_sub_t cnat_sub,
+                 ip_address_family_t af, cnat_session_location_t cs_loc,
+                 u8 do_trace)
 {
   u32 n_left, *from, thread_index;
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE];
   vlib_buffer_t **b = bufs;
   u16 nexts[VLIB_FRAME_SIZE], *next;
   f64 now;
-  u64 seed;
 
   thread_index = vm->thread_index;
   from = vlib_frame_vector_args (frame);
@@ -830,26 +950,25 @@ cnat_node_inline (vlib_main_t * vm,
   next = nexts;
   vlib_get_buffers (vm, from, bufs, n_left);
   now = vlib_time_now (vm);
-  seed = throttle_seed (&cnat_throttle, thread_index, vlib_time_now (vm));
   cnat_session_t *session[4];
-  clib_bihash_kv_40_48_t bkey[4], bvalue[4];
+  cnat_bihash_kv_t bkey[4], bvalue[4];
   u64 hash[4];
   int rv[4];
 
-  cnat_node_ctx_t ctx = { now, seed, thread_index, af, do_trace };
+  cnat_node_ctx_t ctx = { now, thread_index, af, do_trace };
 
   if (n_left >= 8)
     {
       /* Kickstart our state */
-      cnat_session_make_key (b[3], af, &bkey[3]);
-      cnat_session_make_key (b[2], af, &bkey[2]);
-      cnat_session_make_key (b[1], af, &bkey[1]);
-      cnat_session_make_key (b[0], af, &bkey[0]);
-
-      hash[3] = clib_bihash_hash_40_48 (&bkey[3]);
-      hash[2] = clib_bihash_hash_40_48 (&bkey[2]);
-      hash[1] = clib_bihash_hash_40_48 (&bkey[1]);
-      hash[0] = clib_bihash_hash_40_48 (&bkey[0]);
+      cnat_session_make_key (b[3], af, cs_loc, &bkey[3]);
+      cnat_session_make_key (b[2], af, cs_loc, &bkey[2]);
+      cnat_session_make_key (b[1], af, cs_loc, &bkey[1]);
+      cnat_session_make_key (b[0], af, cs_loc, &bkey[0]);
+
+      hash[3] = cnat_bihash_hash (&bkey[3]);
+      hash[2] = cnat_bihash_hash (&bkey[2]);
+      hash[1] = cnat_bihash_hash (&bkey[1]);
+      hash[0] = cnat_bihash_hash (&bkey[0]);
     }
 
   while (n_left >= 8)
@@ -862,53 +981,45 @@ cnat_node_inline (vlib_main_t * vm,
          vlib_prefetch_buffer_header (b[8], LOAD);
        }
 
-      rv[3] =
-       clib_bihash_search_inline_2_with_hash_40_48 (&cnat_session_db,
-                                                    hash[3], &bkey[3],
-                                                    &bvalue[3]);
+      rv[3] = cnat_bihash_search_i2_hash (&cnat_session_db, hash[3], &bkey[3],
+                                         &bvalue[3]);
       session[3] = (cnat_session_t *) (rv[3] ? &bkey[3] : &bvalue[3]);
       next[3] = cnat_sub (vm, node, b[3], &ctx, rv[3], session[3]);
 
-      rv[2] =
-       clib_bihash_search_inline_2_with_hash_40_48 (&cnat_session_db,
-                                                    hash[2], &bkey[2],
-                                                    &bvalue[2]);
+      rv[2] = cnat_bihash_search_i2_hash (&cnat_session_db, hash[2], &bkey[2],
+                                         &bvalue[2]);
       session[2] = (cnat_session_t *) (rv[2] ? &bkey[2] : &bvalue[2]);
       next[2] = cnat_sub (vm, node, b[2], &ctx, rv[2], session[2]);
 
-      rv[1] =
-       clib_bihash_search_inline_2_with_hash_40_48 (&cnat_session_db,
-                                                    hash[1], &bkey[1],
-                                                    &bvalue[1]);
+      rv[1] = cnat_bihash_search_i2_hash (&cnat_session_db, hash[1], &bkey[1],
+                                         &bvalue[1]);
       session[1] = (cnat_session_t *) (rv[1] ? &bkey[1] : &bvalue[1]);
       next[1] = cnat_sub (vm, node, b[1], &ctx, rv[1], session[1]);
 
-      rv[0] =
-       clib_bihash_search_inline_2_with_hash_40_48 (&cnat_session_db,
-                                                    hash[0], &bkey[0],
-                                                    &bvalue[0]);
+      rv[0] = cnat_bihash_search_i2_hash (&cnat_session_db, hash[0], &bkey[0],
+                                         &bvalue[0]);
       session[0] = (cnat_session_t *) (rv[0] ? &bkey[0] : &bvalue[0]);
       next[0] = cnat_sub (vm, node, b[0], &ctx, rv[0], session[0]);
 
-      cnat_session_make_key (b[7], af, &bkey[3]);
-      cnat_session_make_key (b[6], af, &bkey[2]);
-      cnat_session_make_key (b[5], af, &bkey[1]);
-      cnat_session_make_key (b[4], af, &bkey[0]);
+      cnat_session_make_key (b[7], af, cs_loc, &bkey[3]);
+      cnat_session_make_key (b[6], af, cs_loc, &bkey[2]);
+      cnat_session_make_key (b[5], af, cs_loc, &bkey[1]);
+      cnat_session_make_key (b[4], af, cs_loc, &bkey[0]);
 
-      hash[3] = clib_bihash_hash_40_48 (&bkey[3]);
-      hash[2] = clib_bihash_hash_40_48 (&bkey[2]);
-      hash[1] = clib_bihash_hash_40_48 (&bkey[1]);
-      hash[0] = clib_bihash_hash_40_48 (&bkey[0]);
+      hash[3] = cnat_bihash_hash (&bkey[3]);
+      hash[2] = cnat_bihash_hash (&bkey[2]);
+      hash[1] = cnat_bihash_hash (&bkey[1]);
+      hash[0] = cnat_bihash_hash (&bkey[0]);
 
-      clib_bihash_prefetch_bucket_40_48 (&cnat_session_db, hash[3]);
-      clib_bihash_prefetch_bucket_40_48 (&cnat_session_db, hash[2]);
-      clib_bihash_prefetch_bucket_40_48 (&cnat_session_db, hash[1]);
-      clib_bihash_prefetch_bucket_40_48 (&cnat_session_db, hash[0]);
+      cnat_bihash_prefetch_bucket (&cnat_session_db, hash[3]);
+      cnat_bihash_prefetch_bucket (&cnat_session_db, hash[2]);
+      cnat_bihash_prefetch_bucket (&cnat_session_db, hash[1]);
+      cnat_bihash_prefetch_bucket (&cnat_session_db, hash[0]);
 
-      clib_bihash_prefetch_data_40_48 (&cnat_session_db, hash[3]);
-      clib_bihash_prefetch_data_40_48 (&cnat_session_db, hash[2]);
-      clib_bihash_prefetch_data_40_48 (&cnat_session_db, hash[1]);
-      clib_bihash_prefetch_data_40_48 (&cnat_session_db, hash[0]);
+      cnat_bihash_prefetch_data (&cnat_session_db, hash[3]);
+      cnat_bihash_prefetch_data (&cnat_session_db, hash[2]);
+      cnat_bihash_prefetch_data (&cnat_session_db, hash[1]);
+      cnat_bihash_prefetch_data (&cnat_session_db, hash[0]);
 
       b += 4;
       next += 4;
@@ -917,9 +1028,8 @@ cnat_node_inline (vlib_main_t * vm,
 
   while (n_left > 0)
     {
-      cnat_session_make_key (b[0], af, &bkey[0]);
-      rv[0] = clib_bihash_search_inline_2_40_48 (&cnat_session_db,
-                                                &bkey[0], &bvalue[0]);
+      cnat_session_make_key (b[0], af, cs_loc, &bkey[0]);
+      rv[0] = cnat_bihash_search_i2 (&cnat_session_db, &bkey[0], &bvalue[0]);
 
       session[0] = (cnat_session_t *) (rv[0] ? &bkey[0] : &bvalue[0]);
       next[0] = cnat_sub (vm, node, b[0], &ctx, rv[0], session[0]);