Move java,lua api and remaining plugins to src/

Change-Id: I1c3b87e886603678368428ae56a6bd3327cbc90d
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 1597 insertions, 0 deletions

diff --git a/src/plugins/snat/in2out.c b/src/plugins/snat/in2out.c
new file mode 100644
index 00000000000..c78fdd76631
--- /dev/null
+++ b/src/plugins/snat/in2out.c
@@ -0,0 +1,1597 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vnet/handoff.h>
+
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/fib/ip4_fib.h>
+#include <snat/snat.h>
+
+#include <vppinfra/hash.h>
+#include <vppinfra/error.h>
+#include <vppinfra/elog.h>
+
+typedef struct {
+  u32 sw_if_index;
+  u32 next_index;
+  u32 session_index;
+  u32 is_slow_path;
+} snat_in2out_trace_t;
+
+typedef struct {
+  u32 next_worker_index;
+  u8 do_handoff;
+} snat_in2out_worker_handoff_trace_t;
+
+/* packet trace format function */
+static u8 * format_snat_in2out_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 *);
+  snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
+  char * tag;
+
+  tag = t->is_slow_path ? "SNAT_IN2OUT_SLOW_PATH" : "SNAT_IN2OUT_FAST_PATH";
+  
+  s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
+              t->sw_if_index, t->next_index, t->session_index);
+
+  return s;
+}
+
+static u8 * format_snat_in2out_fast_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 *);
+  snat_in2out_trace_t * t = va_arg (*args, snat_in2out_trace_t *);
+
+  s = format (s, "SANT_IN2OUT_FAST: sw_if_index %d, next index %d", 
+              t->sw_if_index, t->next_index);
+
+  return s;
+}
+
+static u8 * format_snat_in2out_worker_handoff_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 *);
+  snat_in2out_worker_handoff_trace_t * t =
+    va_arg (*args, snat_in2out_worker_handoff_trace_t *);
+  char * m;
+
+  m = t->do_handoff ? "next worker" : "same worker";
+  s = format (s, "SNAT_IN2OUT_WORKER_HANDOFF: %s %d", m, t->next_worker_index);
+
+  return s;
+}
+
+vlib_node_registration_t snat_in2out_node;
+vlib_node_registration_t snat_in2out_slowpath_node;
+vlib_node_registration_t snat_in2out_fast_node;
+vlib_node_registration_t snat_in2out_worker_handoff_node;
+
+#define foreach_snat_in2out_error                       \
+_(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
+_(IN2OUT_PACKETS, "Good in2out packets processed")      \
+_(OUT_OF_PORTS, "Out of ports")                         \
+_(BAD_OUTSIDE_FIB, "Outside VRF ID not found")          \
+_(BAD_ICMP_TYPE, "icmp type not echo-request")          \
+_(NO_TRANSLATION, "No translation")
+  
+typedef enum {
+#define _(sym,str) SNAT_IN2OUT_ERROR_##sym,
+  foreach_snat_in2out_error
+#undef _
+  SNAT_IN2OUT_N_ERROR,
+} snat_in2out_error_t;
+
+static char * snat_in2out_error_strings[] = {
+#define _(sym,string) string,
+  foreach_snat_in2out_error
+#undef _
+};
+
+typedef enum {
+  SNAT_IN2OUT_NEXT_LOOKUP,
+  SNAT_IN2OUT_NEXT_DROP,
+  SNAT_IN2OUT_NEXT_SLOW_PATH,
+  SNAT_IN2OUT_N_NEXT,
+} snat_in2out_next_t;
+
+static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
+                      ip4_header_t * ip0,
+                      u32 rx_fib_index0,
+                      snat_session_key_t * key0,
+                      snat_session_t ** sessionp,
+                      vlib_node_runtime_t * node,
+                      u32 next0,
+                      u32 cpu_index)
+{
+  snat_user_t *u;
+  snat_user_key_t user_key;
+  snat_session_t *s;
+  clib_bihash_kv_8_8_t kv0, value0;
+  u32 oldest_per_user_translation_list_index;
+  dlist_elt_t * oldest_per_user_translation_list_elt;
+  dlist_elt_t * per_user_translation_list_elt;
+  dlist_elt_t * per_user_list_head_elt;
+  u32 session_index;
+  snat_session_key_t key1;
+  u32 address_index = ~0;
+  u32 outside_fib_index;
+  uword * p;
+  snat_static_mapping_key_t worker_by_out_key;
+
+  p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->outside_vrf_id);
+  if (! p)
+    {
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_OUTSIDE_FIB];
+      return SNAT_IN2OUT_NEXT_DROP;
+    }
+  outside_fib_index = p[0];
+
+  user_key.addr = ip0->src_address;
+  user_key.fib_index = rx_fib_index0;
+  kv0.key = user_key.as_u64;
+  
+  /* Ever heard of the "user" = src ip4 address before? */
+  if (clib_bihash_search_8_8 (&sm->user_hash, &kv0, &value0))
+    {
+      /* no, make a new one */
+      pool_get (sm->per_thread_data[cpu_index].users, u);
+      memset (u, 0, sizeof (*u));
+      u->addr = ip0->src_address;
+
+      pool_get (sm->per_thread_data[cpu_index].list_pool, per_user_list_head_elt);
+
+      u->sessions_per_user_list_head_index = per_user_list_head_elt -
+        sm->per_thread_data[cpu_index].list_pool;
+
+      clib_dlist_init (sm->per_thread_data[cpu_index].list_pool,
+                       u->sessions_per_user_list_head_index);
+
+      kv0.value = u - sm->per_thread_data[cpu_index].users;
+
+      /* add user */
+      clib_bihash_add_del_8_8 (&sm->user_hash, &kv0, 1 /* is_add */);
+    }
+  else
+    {
+      u = pool_elt_at_index (sm->per_thread_data[cpu_index].users,
+                             value0.value);
+    }
+
+  /* Over quota? Recycle the least recently used dynamic translation */
+  if (u->nsessions >= sm->max_translations_per_user)
+    {
+      /* Remove the oldest dynamic translation */
+      do {
+          oldest_per_user_translation_list_index =
+            clib_dlist_remove_head (sm->per_thread_data[cpu_index].list_pool,
+                                    u->sessions_per_user_list_head_index);
+
+          ASSERT (oldest_per_user_translation_list_index != ~0);
+
+          /* add it back to the end of the LRU list */
+          clib_dlist_addtail (sm->per_thread_data[cpu_index].list_pool,
+                              u->sessions_per_user_list_head_index,
+                              oldest_per_user_translation_list_index);
+          /* Get the list element */
+          oldest_per_user_translation_list_elt =
+            pool_elt_at_index (sm->per_thread_data[cpu_index].list_pool,
+                               oldest_per_user_translation_list_index);
+
+          /* Get the session index from the list element */
+          session_index = oldest_per_user_translation_list_elt->value;
+
+          /* Get the session */
+          s = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
+                                 session_index);
+      } while (snat_is_session_static (s));
+
+      /* Remove in2out, out2in keys */
+      kv0.key = s->in2out.as_u64;
+      if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 0 /* is_add */))
+          clib_warning ("in2out key delete failed");
+      kv0.key = s->out2in.as_u64;
+      if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 0 /* is_add */))
+          clib_warning ("out2in key delete failed");
+
+      snat_free_outside_address_and_port 
+        (sm, &s->out2in, s->outside_address_index);
+      s->outside_address_index = ~0;
+
+      if (snat_alloc_outside_address_and_port (sm, &key1, &address_index))
+        {
+          ASSERT(0);
+
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+          return SNAT_IN2OUT_NEXT_DROP;
+        }
+      s->outside_address_index = address_index;
+    }
+  else
+    {
+      u8 static_mapping = 1;
+
+      /* First try to match static mapping by local address and port */
+      if (snat_static_mapping_match (sm, *key0, &key1, 0))
+        {
+          static_mapping = 0;
+          /* Try to create dynamic translation */
+          if (snat_alloc_outside_address_and_port (sm, &key1, &address_index))
+            {
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+              return SNAT_IN2OUT_NEXT_DROP;
+            }
+        }
+
+      /* Create a new session */
+      pool_get (sm->per_thread_data[cpu_index].sessions, s);
+      memset (s, 0, sizeof (*s));
+      
+      s->outside_address_index = address_index;
+
+      if (static_mapping)
+        {
+          u->nstaticsessions++;
+          s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+        }
+      else
+        {
+          u->nsessions++;
+        }
+
+      /* Create list elts */
+      pool_get (sm->per_thread_data[cpu_index].list_pool,
+                per_user_translation_list_elt);
+      clib_dlist_init (sm->per_thread_data[cpu_index].list_pool,
+                       per_user_translation_list_elt -
+                       sm->per_thread_data[cpu_index].list_pool);
+
+      per_user_translation_list_elt->value =
+        s - sm->per_thread_data[cpu_index].sessions;
+      s->per_user_index = per_user_translation_list_elt -
+                          sm->per_thread_data[cpu_index].list_pool;
+      s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+
+      clib_dlist_addtail (sm->per_thread_data[cpu_index].list_pool,
+                          s->per_user_list_head_index,
+                          per_user_translation_list_elt -
+                          sm->per_thread_data[cpu_index].list_pool);
+   }
+  
+  s->in2out = *key0;
+  s->out2in = key1;
+  s->out2in.protocol = key0->protocol;
+  s->out2in.fib_index = outside_fib_index;
+  *sessionp = s;
+
+  /* Add to translation hashes */
+  kv0.key = s->in2out.as_u64;
+  kv0.value = s - sm->per_thread_data[cpu_index].sessions;
+  if (clib_bihash_add_del_8_8 (&sm->in2out, &kv0, 1 /* is_add */))
+      clib_warning ("in2out key add failed");
+  
+  kv0.key = s->out2in.as_u64;
+  kv0.value = s - sm->per_thread_data[cpu_index].sessions;
+  
+  if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 1 /* is_add */))
+      clib_warning ("out2in key add failed");
+
+  /* Add to translated packets worker lookup */
+  worker_by_out_key.addr = s->out2in.addr;
+  worker_by_out_key.port = s->out2in.port;
+  worker_by_out_key.fib_index = s->out2in.fib_index;
+  kv0.key = worker_by_out_key.as_u64;
+  kv0.value = cpu_index;
+  clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv0, 1);
+  return next0;
+}
+                      
+static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
+                                         vlib_buffer_t * b0,
+                                         ip4_header_t * ip0,
+                                         icmp46_header_t * icmp0,
+                                         u32 sw_if_index0,
+                                         u32 rx_fib_index0,
+                                         vlib_node_runtime_t * node,
+                                         u32 next0,
+                                         f64 now,
+                                         u32 cpu_index)
+{
+  snat_session_key_t key0;
+  icmp_echo_header_t *echo0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  snat_session_t * s0;
+  u32 new_addr0, old_addr0;
+  u16 old_id0, new_id0;
+  ip_csum_t sum0;
+  snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data;
+
+  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request))
+    {
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+      return SNAT_IN2OUT_NEXT_DROP;
+    }
+  
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  key0.addr = ip0->src_address;
+  key0.port = echo0->identifier;
+  key0.protocol = SNAT_PROTOCOL_ICMP;
+  key0.fib_index = rx_fib_index0;
+  
+  kv0.key = key0.as_u64;
+  
+  if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
+    {
+      ip4_address_t * first_int_addr;
+
+      if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
+        {
+          first_int_addr = 
+            ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+                                         0 /* just want the address */);
+          rt->cached_sw_if_index = sw_if_index0;
+          rt->cached_ip4_address = first_int_addr->as_u32;
+        }
+      
+      /* Don't NAT packet aimed at the intfc address */
+      if (PREDICT_FALSE(ip0->dst_address.as_u32 ==
+                                rt->cached_ip4_address))
+        return next0;
+      
+      next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
+                         &s0, node, next0, cpu_index);
+      
+      if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
+        return next0;
+    }
+  else
+    s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
+                            value0.value);
+
+  old_addr0 = ip0->src_address.as_u32;
+  ip0->src_address = s0->out2in.addr;
+  new_addr0 = ip0->src_address.as_u32;
+  vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
+  
+  sum0 = ip0->checksum;
+  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                         ip4_header_t,
+                         src_address /* changed member */);
+  ip0->checksum = ip_csum_fold (sum0);
+  
+  old_id0 = echo0->identifier;
+  new_id0 = s0->out2in.port;
+  echo0->identifier = new_id0;
+
+  sum0 = icmp0->checksum;
+  sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                         identifier);
+  icmp0->checksum = ip_csum_fold (sum0);
+
+  /* Accounting */
+  s0->last_heard = now;
+  s0->total_pkts++;
+  s0->total_bytes += vlib_buffer_length_in_chain (sm->vlib_main, b0);
+  /* Per-user LRU list maintenance for dynamic translations */
+  if (!snat_is_session_static (s0))
+    {
+      clib_dlist_remove (sm->per_thread_data[cpu_index].list_pool,
+                         s0->per_user_index);
+      clib_dlist_addtail (sm->per_thread_data[cpu_index].list_pool,
+                          s0->per_user_list_head_index,
+                          s0->per_user_index);
+    }
+
+  return next0;
+}
+
+/**
+ * @brief Hairpinning
+ *
+ * Hairpinning allows two endpoints on the internal side of the NAT to
+ * communicate even if they only use each other's external IP addresses
+ * and ports.
+ *
+ * @param sm     SNAT main.
+ * @param b0     Vlib buffer.
+ * @param ip0    IP header.
+ * @param udp0   UDP header.
+ * @param tcp0   TCP header.
+ * @param proto0 SNAT protocol.
+ */
+static inline void
+snat_hairpinning (snat_main_t *sm,
+                  vlib_buffer_t * b0,
+                  ip4_header_t * ip0,
+                  udp_header_t * udp0,
+                  tcp_header_t * tcp0,
+                  u32 proto0)
+{
+  snat_session_key_t key0, sm0;
+  snat_static_mapping_key_t k0;
+  snat_session_t * s0;
+  clib_bihash_kv_8_8_t kv0, value0;
+  ip_csum_t sum0;
+  u32 new_dst_addr0 = 0, old_dst_addr0, ti = 0, si;
+  u16 new_dst_port0, old_dst_port0;
+
+  key0.addr = ip0->dst_address;
+  key0.port = udp0->dst_port;
+  key0.protocol = proto0;
+  key0.fib_index = sm->outside_fib_index;
+  kv0.key = key0.as_u64;
+
+  /* Check if destination is in active sessions */
+  if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+    {
+      /* or static mappings */
+      if (!snat_static_mapping_match(sm, key0, &sm0, 1))
+        {
+          new_dst_addr0 = sm0.addr.as_u32;
+          new_dst_port0 = sm0.port;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+        }
+    }
+  else
+    {
+      si = value0.value;
+      if (sm->num_workers > 1)
+        {
+          k0.addr = ip0->dst_address;
+          k0.port = udp0->dst_port;
+          k0.fib_index = sm->outside_fib_index;
+          kv0.key = k0.as_u64;
+          if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+            ASSERT(0);
+          else
+            ti = value0.value;
+        }
+      else
+        ti = sm->num_workers;
+
+      s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
+      new_dst_addr0 = s0->in2out.addr.as_u32;
+      new_dst_port0 = s0->in2out.port;
+      vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+    }
+
+  /* Destination is behind the same NAT, use internal address and port */
+  if (new_dst_addr0)
+    {
+      old_dst_addr0 = ip0->dst_address.as_u32;
+      ip0->dst_address.as_u32 = new_dst_addr0;
+      sum0 = ip0->checksum;
+      sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+                             ip4_header_t, dst_address);
+      ip0->checksum = ip_csum_fold (sum0);
+
+      old_dst_port0 = tcp0->ports.dst;
+      if (PREDICT_TRUE(new_dst_port0 != old_dst_port0))
+        {
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              tcp0->ports.dst = new_dst_port0;
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+                                     ip4_header_t, dst_address);
+              sum0 = ip_csum_update (sum0, old_dst_port0, new_dst_port0,
+                                     ip4_header_t /* cheat */, length);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              udp0->dst_port = new_dst_port0;
+              udp0->checksum = 0;
+            }
+        }
+    }
+}
+
+static inline uword
+snat_in2out_node_fn_inline (vlib_main_t * vm,
+                            vlib_node_runtime_t * node,
+                            vlib_frame_t * frame, int is_slow_path)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data;
+  f64 now = vlib_time_now (vm);
+  u32 stats_node_index;
+  u32 cpu_index = os_get_cpu_number ();
+
+  stats_node_index = is_slow_path ? snat_in2out_slowpath_node.index :
+    snat_in2out_node.index;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+	{
+          u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+          u32 next0, next1;
+          u32 sw_if_index0, sw_if_index1;
+          ip4_header_t * ip0, * ip1;
+          ip_csum_t sum0, sum1;
+          u32 new_addr0, old_addr0, new_addr1, old_addr1;
+          u16 old_port0, new_port0, old_port1, new_port1;
+          udp_header_t * udp0, * udp1;
+          tcp_header_t * tcp0, * tcp1;
+          icmp46_header_t * icmp0, * icmp1;
+          snat_session_key_t key0, key1;
+          u32 rx_fib_index0, rx_fib_index1;
+          u32 proto0, proto1;
+          snat_session_t * s0 = 0, * s1 = 0;
+          clib_bihash_kv_8_8_t kv0, value0, kv1, value1;
+          
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t * p2, * p3;
+            
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+            
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
+	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
+	  }
+
+          /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+          
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, 
+                                   sw_if_index0);
+
+          next0 = next1 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          proto0 = ~0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_UDP) 
+            ? SNAT_PROTOCOL_UDP : proto0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_TCP) 
+            ? SNAT_PROTOCOL_TCP : proto0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_ICMP) 
+            ? SNAT_PROTOCOL_ICMP : proto0;
+
+          /* Next configured feature, probably ip4-lookup */
+          if (is_slow_path)
+            {
+              if (PREDICT_FALSE (proto0 == ~0))
+                goto trace00;
+              
+              if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = icmp_in2out_slow_path 
+                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, 
+                     node, next0, now, cpu_index);
+                  goto trace00;
+                }
+            }
+          else
+            {
+              if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace00;
+                }
+            }
+
+          key0.addr = ip0->src_address;
+          key0.port = udp0->src_port;
+          key0.protocol = proto0;
+          key0.fib_index = rx_fib_index0;
+          
+          kv0.key = key0.as_u64;
+
+          if (PREDICT_FALSE (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0) != 0))
+            {
+              if (is_slow_path)
+                {
+                  ip4_address_t * first_int_addr;
+                  
+                  if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
+                    {
+                      first_int_addr = 
+                        ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+                                                     0 /* just want the address */);
+                      rt->cached_sw_if_index = sw_if_index0;
+                      rt->cached_ip4_address = first_int_addr->as_u32;
+                    }
+                  
+                  /* Don't NAT packet aimed at the intfc address */
+                  if (PREDICT_FALSE(ip0->dst_address.as_u32 ==
+                                    rt->cached_ip4_address))
+                    goto trace00;
+                  
+                  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
+                                     &s0, node, next0, cpu_index);
+                  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
+                    goto trace00;
+                }
+              else
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace00;
+                }
+            }
+          else
+            s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
+                                    value0.value);
+
+          old_addr0 = ip0->src_address.as_u32;
+          ip0->src_address = s0->out2in.addr;
+          new_addr0 = ip0->src_address.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              old_port0 = tcp0->ports.src;
+              tcp0->ports.src = s0->out2in.port;
+              new_port0 = tcp0->ports.src;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->src_port;
+              udp0->src_port = s0->out2in.port;
+              udp0->checksum = 0;
+            }
+
+          /* Hairpinning */
+          snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+
+          /* Accounting */
+          s0->last_heard = now;
+          s0->total_pkts++;
+          s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s0))
+            {
+              clib_dlist_remove (sm->per_thread_data[cpu_index].list_pool,
+                                 s0->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[cpu_index].list_pool,
+                                  s0->per_user_list_head_index,
+                                  s0->per_user_index);
+            }
+        trace00:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) 
+            {
+              snat_in2out_trace_t *t = 
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->is_slow_path = is_slow_path;
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+                  t->session_index = ~0;
+              if (s0)
+                t->session_index = s0 - sm->per_thread_data[cpu_index].sessions;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          ip1 = vlib_buffer_get_current (b1);
+          udp1 = ip4_next_header (ip1);
+          tcp1 = (tcp_header_t *) udp1;
+          icmp1 = (icmp46_header_t *) udp1;
+
+          sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
+	  rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, 
+                                   sw_if_index1);
+
+          proto1 = ~0;
+          proto1 = (ip1->protocol == IP_PROTOCOL_UDP) 
+            ? SNAT_PROTOCOL_UDP : proto1;
+          proto1 = (ip1->protocol == IP_PROTOCOL_TCP) 
+            ? SNAT_PROTOCOL_TCP : proto1;
+          proto1 = (ip1->protocol == IP_PROTOCOL_ICMP) 
+            ? SNAT_PROTOCOL_ICMP : proto1;
+
+          /* Next configured feature, probably ip4-lookup */
+          if (is_slow_path)
+            {
+              if (PREDICT_FALSE (proto1 == ~0))
+                goto trace01;
+              
+              if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
+                {
+                  next1 = icmp_in2out_slow_path 
+                    (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
+                     next1, now, cpu_index);
+                  goto trace01;
+                }
+            }
+          else
+            {
+              if (PREDICT_FALSE (proto1 == ~0 || proto1 == SNAT_PROTOCOL_ICMP))
+                {
+                  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace01;
+                }
+            }
+
+          key1.addr = ip1->src_address;
+          key1.port = udp1->src_port;
+          key1.protocol = proto1;
+          key1.fib_index = rx_fib_index1;
+          
+          kv1.key = key1.as_u64;
+
+            if (PREDICT_FALSE(clib_bihash_search_8_8 (&sm->in2out, &kv1, &value1) != 0))
+            {
+              if (is_slow_path)
+                {
+                  ip4_address_t * first_int_addr;
+                  
+                  if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index1))
+                    {
+                      first_int_addr = 
+                        ip4_interface_first_address (sm->ip4_main, sw_if_index1,
+                                                     0 /* just want the address */);
+                      rt->cached_sw_if_index = sw_if_index1;
+                      rt->cached_ip4_address = first_int_addr->as_u32;
+                    }
+                  
+                  /* Don't NAT packet aimed at the intfc address */
+                  if (PREDICT_FALSE(ip1->dst_address.as_u32 ==
+                                    rt->cached_ip4_address))
+                    goto trace01;
+                  
+                  next1 = slow_path (sm, b1, ip1, rx_fib_index1, &key1,
+                                     &s1, node, next1, cpu_index);
+                  if (PREDICT_FALSE (next1 == SNAT_IN2OUT_NEXT_DROP))
+                    goto trace01;
+                }
+              else
+                {
+                  next1 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace01;
+                }
+            }
+          else
+            s1 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
+                                    value1.value);
+
+          old_addr1 = ip1->src_address.as_u32;
+          ip1->src_address = s1->out2in.addr;
+          new_addr1 = ip1->src_address.as_u32;
+          vnet_buffer(b1)->sw_if_index[VLIB_TX] = s1->out2in.fib_index;
+
+          sum1 = ip1->checksum;
+          sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip1->checksum = ip_csum_fold (sum1);
+
+          if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
+            {
+              old_port1 = tcp1->ports.src;
+              tcp1->ports.src = s1->out2in.port;
+              new_port1 = tcp1->ports.src;
+
+              sum1 = tcp1->checksum;
+              sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum1 = ip_csum_update (sum1, old_port1, new_port1,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp1->checksum = ip_csum_fold(sum1);
+            }
+          else
+            {
+              old_port1 = udp1->src_port;
+              udp1->src_port = s1->out2in.port;
+              udp1->checksum = 0;
+            }
+
+          /* Hairpinning */
+          snat_hairpinning (sm, b1, ip1, udp1, tcp1, proto1);
+
+          /* Accounting */
+          s1->last_heard = now;
+          s1->total_pkts++;
+          s1->total_bytes += vlib_buffer_length_in_chain (vm, b1);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s1))
+            {
+              clib_dlist_remove (sm->per_thread_data[cpu_index].list_pool,
+                                 s1->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[cpu_index].list_pool,
+                                  s1->per_user_list_head_index,
+                                  s1->per_user_index);
+            }
+        trace01:
+
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
+                            && (b1->flags & VLIB_BUFFER_IS_TRACED))) 
+            {
+              snat_in2out_trace_t *t = 
+                 vlib_add_trace (vm, node, b1, sizeof (*t));
+              t->sw_if_index = sw_if_index1;
+              t->next_index = next1;
+              t->session_index = ~0;
+              if (s1)
+                t->session_index = s1 - sm->per_thread_data[cpu_index].sessions;
+            }
+
+          pkts_processed += next1 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueues, maybe switch current next frame */
+          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+                                           to_next, n_left_to_next,
+                                           bi0, bi1, next0, next1);
+        }
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          u32 new_addr0, old_addr0;
+          u16 old_port0, new_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          icmp46_header_t * icmp0;
+          snat_session_key_t key0;
+          u32 rx_fib_index0;
+          u32 proto0;
+          snat_session_t * s0 = 0;
+          clib_bihash_kv_8_8_t kv0, value0;
+          
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, 
+                                   sw_if_index0);
+
+          proto0 = ~0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_UDP) 
+            ? SNAT_PROTOCOL_UDP : proto0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_TCP) 
+            ? SNAT_PROTOCOL_TCP : proto0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_ICMP) 
+            ? SNAT_PROTOCOL_ICMP : proto0;
+
+          /* Next configured feature, probably ip4-lookup */
+          if (is_slow_path)
+            {
+              if (PREDICT_FALSE (proto0 == ~0))
+                goto trace0;
+              
+              if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = icmp_in2out_slow_path 
+                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
+                     next0, now, cpu_index);
+                  goto trace0;
+                }
+            }
+          else
+            {
+              if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP))
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace0;
+                }
+            }
+
+          key0.addr = ip0->src_address;
+          key0.port = udp0->src_port;
+          key0.protocol = proto0;
+          key0.fib_index = rx_fib_index0;
+          
+          kv0.key = key0.as_u64;
+
+          if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
+            {
+              if (is_slow_path)
+                {
+                  ip4_address_t * first_int_addr;
+                  
+                  if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
+                    {
+                      first_int_addr = 
+                        ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+                                                     0 /* just want the address */);
+                      rt->cached_sw_if_index = sw_if_index0;
+                      rt->cached_ip4_address = first_int_addr->as_u32;
+                    }
+                  
+                  /* Don't NAT packet aimed at the intfc address */
+                  if (PREDICT_FALSE(ip0->dst_address.as_u32 ==
+                                    rt->cached_ip4_address))
+                    goto trace0;
+                  
+                  next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
+                                     &s0, node, next0, cpu_index);
+                  if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
+                    goto trace0;
+                }
+              else
+                {
+                  next0 = SNAT_IN2OUT_NEXT_SLOW_PATH;
+                  goto trace0;
+                }
+            }
+          else
+            s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
+                                    value0.value);
+
+          old_addr0 = ip0->src_address.as_u32;
+          ip0->src_address = s0->out2in.addr;
+          new_addr0 = ip0->src_address.as_u32;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+            {
+              old_port0 = tcp0->ports.src;
+              tcp0->ports.src = s0->out2in.port;
+              new_port0 = tcp0->ports.src;
+
+              sum0 = tcp0->checksum;
+              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                     ip4_header_t,
+                                     dst_address /* changed member */);
+              sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                     ip4_header_t /* cheat */,
+                                     length /* changed member */);
+              tcp0->checksum = ip_csum_fold(sum0);
+            }
+          else
+            {
+              old_port0 = udp0->src_port;
+              udp0->src_port = s0->out2in.port;
+              udp0->checksum = 0;
+            }
+
+          /* Hairpinning */
+          snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+
+          /* Accounting */
+          s0->last_heard = now;
+          s0->total_pkts++;
+          s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
+          /* Per-user LRU list maintenance for dynamic translation */
+          if (!snat_is_session_static (s0))
+            {
+              clib_dlist_remove (sm->per_thread_data[cpu_index].list_pool,
+                                 s0->per_user_index);
+              clib_dlist_addtail (sm->per_thread_data[cpu_index].list_pool,
+                                  s0->per_user_list_head_index,
+                                  s0->per_user_index);
+            }
+
+        trace0:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) 
+            {
+              snat_in2out_trace_t *t = 
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->is_slow_path = is_slow_path;
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+                  t->session_index = ~0;
+              if (s0)
+                t->session_index = s0 - sm->per_thread_data[cpu_index].sessions;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, stats_node_index, 
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS, 
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+static uword
+snat_in2out_fast_path_fn (vlib_main_t * vm,
+                          vlib_node_runtime_t * node,
+                          vlib_frame_t * frame)
+{
+  return snat_in2out_node_fn_inline (vm, node, frame, 0 /* is_slow_path */);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_node) = {
+  .function = snat_in2out_fast_path_fn,
+  .name = "snat-in2out",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+  
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_node, snat_in2out_fast_path_fn);
+
+static uword
+snat_in2out_slow_path_fn (vlib_main_t * vm,
+                          vlib_node_runtime_t * node,
+                          vlib_frame_t * frame)
+{
+  return snat_in2out_node_fn_inline (vm, node, frame, 1 /* is_slow_path */);
+}
+
+VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
+  .function = snat_in2out_slow_path_fn,
+  .name = "snat-in2out-slowpath",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+  
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_slowpath_node, snat_in2out_slow_path_fn);
+
+static uword
+snat_in2out_worker_handoff_fn (vlib_main_t * vm,
+                               vlib_node_runtime_t * node,
+                               vlib_frame_t * frame)
+{
+  snat_main_t *sm = &snat_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  u32 n_left_from, *from, *to_next = 0;
+  static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
+  static __thread vlib_frame_queue_t **congested_handoff_queue_by_worker_index
+    = 0;
+  vlib_frame_queue_elt_t *hf = 0;
+  vlib_frame_t *f = 0;
+  int i;
+  u32 n_left_to_next_worker = 0, *to_next_worker = 0;
+  u32 next_worker_index = 0;
+  u32 current_worker_index = ~0;
+  u32 cpu_index = os_get_cpu_number ();
+
+  ASSERT (vec_len (sm->workers));
+
+  if (PREDICT_FALSE (handoff_queue_elt_by_worker_index == 0))
+    {
+      vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
+
+      vec_validate_init_empty (congested_handoff_queue_by_worker_index,
+			       sm->first_worker_index + sm->num_workers - 1,
+			       (vlib_frame_queue_t *) (~0));
+    }
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+
+  while (n_left_from > 0)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      u32 sw_if_index0;
+      u32 rx_fib_index0;
+      ip4_header_t * ip0;
+      snat_user_key_t key0;
+      clib_bihash_kv_8_8_t kv0, value0;
+      u8 do_handoff;
+
+      bi0 = from[0];
+      from += 1;
+      n_left_from -= 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+
+      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+      rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+
+      ip0 = vlib_buffer_get_current (b0);
+
+      key0.addr = ip0->src_address;
+      key0.fib_index = rx_fib_index0;
+
+      kv0.key = key0.as_u64;
+
+      /* Ever heard of of the "user" before? */
+      if (clib_bihash_search_8_8 (&sm->worker_by_in, &kv0, &value0))
+        {
+          /* No, assign next available worker (RR) */
+          next_worker_index = sm->first_worker_index +
+            sm->workers[sm->next_worker++ % vec_len (sm->workers)];
+
+          /* add non-traslated packets worker lookup */
+          kv0.value = next_worker_index;
+          clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv0, 1);
+        }
+      else
+        next_worker_index = value0.value;
+
+      if (PREDICT_FALSE (next_worker_index != cpu_index))
+        {
+          do_handoff = 1;
+
+          if (next_worker_index != current_worker_index)
+            {
+              if (hf)
+                hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
+
+              hf = vlib_get_worker_handoff_queue_elt (sm->fq_in2out_index,
+                                                      next_worker_index,
+                                                      handoff_queue_elt_by_worker_index);
+
+              n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
+              to_next_worker = &hf->buffer_index[hf->n_vectors];
+              current_worker_index = next_worker_index;
+            }
+
+          /* enqueue to correct worker thread */
+          to_next_worker[0] = bi0;
+          to_next_worker++;
+          n_left_to_next_worker--;
+
+          if (n_left_to_next_worker == 0)
+            {
+              hf->n_vectors = VLIB_FRAME_SIZE;
+              vlib_put_frame_queue_elt (hf);
+              current_worker_index = ~0;
+              handoff_queue_elt_by_worker_index[next_worker_index] = 0;
+              hf = 0;
+            }
+        }
+      else
+        {
+          do_handoff = 0;
+          /* if this is 1st frame */
+          if (!f)
+            {
+              f = vlib_get_frame_to_node (vm, snat_in2out_node.index);
+              to_next = vlib_frame_vector_args (f);
+            }
+
+          to_next[0] = bi0;
+          to_next += 1;
+          f->n_vectors++;
+        }
+
+      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	{
+          snat_in2out_worker_handoff_trace_t *t =
+            vlib_add_trace (vm, node, b0, sizeof (*t));
+          t->next_worker_index = next_worker_index;
+          t->do_handoff = do_handoff;
+        }
+    }
+
+  if (f)
+    vlib_put_frame_to_node (vm, snat_in2out_node.index, f);
+
+  if (hf)
+    hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
+
+  /* Ship frames to the worker nodes */
+  for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
+    {
+      if (handoff_queue_elt_by_worker_index[i])
+	{
+	  hf = handoff_queue_elt_by_worker_index[i];
+	  /*
+	   * It works better to let the handoff node
+	   * rate-adapt, always ship the handoff queue element.
+	   */
+	  if (1 || hf->n_vectors == hf->last_n_vectors)
+	    {
+	      vlib_put_frame_queue_elt (hf);
+	      handoff_queue_elt_by_worker_index[i] = 0;
+	    }
+	  else
+	    hf->last_n_vectors = hf->n_vectors;
+	}
+      congested_handoff_queue_by_worker_index[i] =
+	(vlib_frame_queue_t *) (~0);
+    }
+  hf = 0;
+  current_worker_index = ~0;
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (snat_in2out_worker_handoff_node) = {
+  .function = snat_in2out_worker_handoff_fn,
+  .name = "snat-in2out-worker-handoff",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_worker_handoff_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  
+  .n_next_nodes = 1,
+
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_worker_handoff_node, snat_in2out_worker_handoff_fn);
+
+static inline u32 icmp_in2out_static_map (snat_main_t *sm,
+                                          vlib_buffer_t * b0,
+                                          ip4_header_t * ip0,
+                                          icmp46_header_t * icmp0,
+                                          u32 sw_if_index0,
+                                          vlib_node_runtime_t * node,
+                                          u32 next0,
+                                          u32 rx_fib_index0)
+{
+  snat_session_key_t key0, sm0;
+  icmp_echo_header_t *echo0;
+  u32 new_addr0, old_addr0;
+  u16 old_id0, new_id0;
+  ip_csum_t sum0;
+  snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data;
+
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  key0.addr = ip0->src_address;
+  key0.port = echo0->identifier;
+  key0.fib_index = rx_fib_index0;
+  
+  if (snat_static_mapping_match(sm, key0, &sm0, 0))
+    {
+      ip4_address_t * first_int_addr;
+
+      if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
+        {
+          first_int_addr =
+            ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+                                         0 /* just want the address */);
+          rt->cached_sw_if_index = sw_if_index0;
+          rt->cached_ip4_address = first_int_addr->as_u32;
+        }
+
+      /* Don't NAT packet aimed at the intfc address */
+      if (PREDICT_FALSE(ip0->dst_address.as_u32 ==
+                                rt->cached_ip4_address))
+        return next0;
+
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+      return SNAT_IN2OUT_NEXT_DROP;
+    }
+
+  new_addr0 = sm0.addr.as_u32;
+  new_id0 = sm0.port;
+  vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+  old_addr0 = ip0->src_address.as_u32;
+  ip0->src_address.as_u32 = new_addr0;
+  
+  sum0 = ip0->checksum;
+  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                         ip4_header_t,
+                         src_address /* changed member */);
+  ip0->checksum = ip_csum_fold (sum0);
+  
+  if (PREDICT_FALSE(new_id0 != echo0->identifier))
+    {
+      old_id0 = echo0->identifier;
+      echo0->identifier = new_id0;
+
+      sum0 = icmp0->checksum;
+      sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                             identifier);
+      icmp0->checksum = ip_csum_fold (sum0);
+    }
+
+  return next0;
+}
+
+static uword
+snat_in2out_fast_static_map_fn (vlib_main_t * vm,
+                                vlib_node_runtime_t * node,
+                                vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  snat_in2out_next_t next_index;
+  u32 pkts_processed = 0;
+  snat_main_t * sm = &snat_main;
+  snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data;
+  u32 stats_node_index;
+
+  stats_node_index = snat_in2out_fast_node.index;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index,
+			   to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+          u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 next0;
+          u32 sw_if_index0;
+          ip4_header_t * ip0;
+          ip_csum_t sum0;
+          u32 new_addr0, old_addr0;
+          u16 old_port0, new_port0;
+          udp_header_t * udp0;
+          tcp_header_t * tcp0;
+          icmp46_header_t * icmp0;
+          snat_session_key_t key0, sm0;
+          u32 proto0;
+          u32 rx_fib_index0;
+
+          /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+          next0 = SNAT_IN2OUT_NEXT_LOOKUP;
+
+          ip0 = vlib_buffer_get_current (b0);
+          udp0 = ip4_next_header (ip0);
+          tcp0 = (tcp_header_t *) udp0;
+          icmp0 = (icmp46_header_t *) udp0;
+
+          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+	  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index(sw_if_index0);
+
+          proto0 = ~0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_UDP)
+            ? SNAT_PROTOCOL_UDP : proto0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_TCP)
+            ? SNAT_PROTOCOL_TCP : proto0;
+          proto0 = (ip0->protocol == IP_PROTOCOL_ICMP)
+            ? SNAT_PROTOCOL_ICMP : proto0;
+
+          if (PREDICT_FALSE (proto0 == ~0))
+              goto trace0;
+
+          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+            {
+              ip4_address_t * first_int_addr;
+              
+              if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
+                {
+                  first_int_addr = 
+                    ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+                                                 0 /* just want the address */);
+                  rt->cached_sw_if_index = sw_if_index0;
+                  rt->cached_ip4_address = first_int_addr->as_u32;
+                }
+              
+              /* Don't NAT packet aimed at the intfc address */
+              if (PREDICT_FALSE(ip0->dst_address.as_u32 ==
+                                rt->cached_ip4_address))
+                goto trace0;
+
+              next0 = icmp_in2out_static_map
+                (sm, b0, ip0, icmp0, sw_if_index0, node, next0, rx_fib_index0);
+              goto trace0;
+            }
+
+          key0.addr = ip0->src_address;
+          key0.port = udp0->src_port;
+          key0.fib_index = rx_fib_index0;
+
+          if (snat_static_mapping_match(sm, key0, &sm0, 0))
+            {
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
+              next0= SNAT_IN2OUT_NEXT_DROP;
+              goto trace0;
+            }
+
+          new_addr0 = sm0.addr.as_u32;
+          new_port0 = sm0.port;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+          old_addr0 = ip0->src_address.as_u32;
+          ip0->src_address.as_u32 = new_addr0;
+
+          sum0 = ip0->checksum;
+          sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                 ip4_header_t,
+                                 src_address /* changed member */);
+          ip0->checksum = ip_csum_fold (sum0);
+
+          if (PREDICT_FALSE(new_port0 != udp0->dst_port))
+            {
+              if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+                {
+                  old_port0 = tcp0->ports.src;
+                  tcp0->ports.src = new_port0;
+
+                  sum0 = tcp0->checksum;
+                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                         ip4_header_t,
+                                         dst_address /* changed member */);
+                  sum0 = ip_csum_update (sum0, old_port0, new_port0,
+                                         ip4_header_t /* cheat */,
+                                         length /* changed member */);
+                  tcp0->checksum = ip_csum_fold(sum0);
+                }
+              else
+                {
+                  old_port0 = udp0->src_port;
+                  udp0->src_port = new_port0;
+                  udp0->checksum = 0;
+                }
+            }
+          else
+            {
+              if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
+                {
+                  sum0 = tcp0->checksum;
+                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                         ip4_header_t,
+                                         dst_address /* changed member */);
+                  tcp0->checksum = ip_csum_fold(sum0);
+                }
+            }
+
+          /* Hairpinning */
+          snat_hairpinning (sm, b0, ip0, udp0, tcp0, proto0);
+
+        trace0:
+          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
+                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+            {
+              snat_in2out_trace_t *t =
+                 vlib_add_trace (vm, node, b0, sizeof (*t));
+              t->sw_if_index = sw_if_index0;
+              t->next_index = next0;
+            }
+
+          pkts_processed += next0 != SNAT_IN2OUT_NEXT_DROP;
+
+          /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, stats_node_index,
+                               SNAT_IN2OUT_ERROR_IN2OUT_PACKETS,
+                               pkts_processed);
+  return frame->n_vectors;
+}
+
+
+VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
+  .function = snat_in2out_fast_static_map_fn,
+  .name = "snat-in2out-fast",
+  .vector_size = sizeof (u32),
+  .format_trace = format_snat_in2out_fast_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  
+  .n_errors = ARRAY_LEN(snat_in2out_error_strings),
+  .error_strings = snat_in2out_error_strings,
+
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+  
+  .n_next_nodes = SNAT_IN2OUT_N_NEXT,
+
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [SNAT_IN2OUT_NEXT_DROP] = "error-drop",
+    [SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
+    [SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_fast_node, snat_in2out_fast_static_map_fn);