nat: fixed input validation
[vpp.git] / src / plugins / nat / in2out_ed.c
index ca1d0cd..54c866b 100644 (file)
@@ -31,6 +31,8 @@
 #include <nat/nat44/inlines.h>
 #include <nat/nat_syslog.h>
 #include <nat/nat_ha.h>
+#include <nat/nat44/ed_inlines.h>
+#include <nat/lib/nat_inlines.h>
 
 static char *nat_in2out_ed_error_strings[] = {
 #define _(sym,string) string,
@@ -72,7 +74,10 @@ nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
   nat44_is_idle_session_ctx_t *ctx = arg;
   snat_session_t *s;
   u64 sess_timeout_time;
-  nat_ed_ses_key_t ed_key;
+  u8 proto;
+  u16 r_port, l_port;
+  ip4_address_t *l_addr, *r_addr;
+  u32 fib_index;
   clib_bihash_kv_16_8_t ed_kv;
   int i;
   snat_address_t *a;
@@ -80,31 +85,32 @@ nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
                                                       ctx->thread_index);
 
-  s = pool_elt_at_index (tsm->sessions, kv->value);
+  ASSERT (ctx->thread_index == ed_value_get_thread_index (kv));
+  s = pool_elt_at_index (tsm->sessions, ed_value_get_session_index (kv));
   sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
   if (ctx->now >= sess_timeout_time)
     {
       if (is_fwd_bypass_session (s))
        goto delete;
 
-      ed_key.l_addr = s->out2in.addr;
-      ed_key.r_addr = s->ext_host_addr;
-      ed_key.fib_index = s->out2in.fib_index;
+      l_addr = &s->out2in.addr;
+      r_addr = &s->ext_host_addr;
+      fib_index = s->out2in.fib_index;
       if (snat_is_unk_proto_session (s))
        {
-         ed_key.proto = s->in2out.port;
-         ed_key.r_port = 0;
-         ed_key.l_port = 0;
+         proto = s->in2out.port;
+         r_port = 0;
+         l_port = 0;
        }
       else
        {
-         ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
-         ed_key.l_port = s->out2in.port;
-         ed_key.r_port = s->ext_host_port;
+         proto = nat_proto_to_ip_proto (s->in2out.protocol);
+         l_port = s->out2in.port;
+         r_port = s->ext_host_port;
        }
-      ed_kv.key[0] = ed_key.as_u64[0];
-      ed_kv.key[1] = ed_key.as_u64[1];
-      if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &ed_kv, 0))
+      make_ed_kv (l_addr, r_addr, proto, fib_index, l_port, r_port, ~0, ~0,
+                 &ed_kv);
+      if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &ed_kv, 0))
        nat_elog_warn ("out2in_ed key del failed");
 
       if (snat_is_unk_proto_session (s))
@@ -152,7 +158,7 @@ nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
       snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
                                          &s->out2in);
     delete:
-      nat44_delete_session (sm, s, ctx->thread_index);
+      nat_ed_session_delete (sm, s, ctx->thread_index, 1);
       return 1;
     }
 
@@ -167,6 +173,8 @@ icmp_in2out_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
                          vlib_node_runtime_t * node, u32 next0, f64 now,
                          u32 thread_index, snat_session_t ** p_s0)
 {
+  vlib_main_t *vm = vlib_get_main ();
+
   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
                       next0, thread_index, p_s0, 0);
   snat_session_t *s0 = *p_s0;
@@ -175,7 +183,7 @@ icmp_in2out_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
       /* Accounting */
       nat44_session_update_counters (s0, now,
                                     vlib_buffer_length_in_chain
-                                    (sm->vlib_main, b0), thread_index);
+                                    (vm, b0), thread_index);
       /* Per-user LRU list maintenance */
       nat44_session_update_lru (sm, s0, thread_index);
     }
@@ -191,11 +199,13 @@ snat_random_port (u16 min, u16 max)
 }
 
 static int
-nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 fib_index,
-                           u32 thread_index, nat_ed_ses_key_t * key,
-                           snat_session_key_t * key1, u16 port_per_thread,
-                           u32 snat_thread_index,
+nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 rx_fib_index,
+                           u32 nat_proto, u32 thread_index,
+                           ip4_address_t r_addr, u16 r_port, u8 proto,
+                           u16 port_per_thread, u32 snat_thread_index,
                            snat_session_t * s,
+                           ip4_address_t * allocated_addr,
+                           u16 * allocated_port,
                            clib_bihash_kv_16_8_t * out2in_ed_kv)
 {
   int i;
@@ -208,11 +218,11 @@ nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 fib_index,
   for (i = 0; i < vec_len (sm->addresses); i++)
     {
       a = sm->addresses + i;
-      switch (key1->protocol)
+      switch (nat_proto)
        {
 #define _(N, j, n, unused)                                                    \
-  case SNAT_PROTOCOL_##N:                                                     \
-    if (a->fib_index == fib_index)                                            \
+  case NAT_PROTOCOL_##N:                                                     \
+    if (a->fib_index == rx_fib_index)                                         \
       {                                                                       \
         u16 port = snat_random_port (1, port_per_thread);                     \
         u16 attempts = port_per_thread;                                       \
@@ -220,19 +230,18 @@ nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 fib_index,
           {                                                                   \
             --attempts;                                                       \
             portnum = port_thread_offset + port;                              \
-            make_ed_kv (out2in_ed_kv, &a->addr, &key->r_addr, key->proto,     \
-                        s->out2in.fib_index, clib_host_to_net_u16 (portnum),  \
-                        key->r_port);                                         \
-            out2in_ed_kv->value = s - tsm->sessions;                          \
-            int rv = clib_bihash_add_del_16_8 (&tsm->out2in_ed, out2in_ed_kv, \
+            make_ed_kv (&a->addr, &r_addr, proto, s->out2in.fib_index,        \
+                        clib_host_to_net_u16 (portnum), r_port, thread_index, \
+                        s - tsm->sessions, out2in_ed_kv);                     \
+            int rv = clib_bihash_add_del_16_8 (&sm->out2in_ed, out2in_ed_kv,  \
                                                2 /* is_add */);               \
             if (0 == rv)                                                      \
               {                                                               \
                 ++a->busy_##n##_port_refcounts[portnum];                      \
                 a->busy_##n##_ports_per_thread[thread_index]++;               \
                 a->busy_##n##_ports++;                                        \
-                key1->addr = a->addr;                                         \
-                key1->port = clib_host_to_net_u16 (portnum);                  \
+                *allocated_addr = a->addr;                                    \
+                *allocated_port = clib_host_to_net_u16 (portnum);             \
                 return 0;                                                     \
               }                                                               \
             port = (port + 1) % port_per_thread;                              \
@@ -244,7 +253,7 @@ nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 fib_index,
       }                                                                       \
     break;
 
-         foreach_snat_protocol;
+         foreach_nat_protocol;
        default:
          nat_elog_info ("unknown protocol");
          return 1;
@@ -254,11 +263,11 @@ nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 fib_index,
   if (ga)
     {
       /* fake fib_index to reuse macro */
-      fib_index = ~0;
+      rx_fib_index = ~0;
       a = ga;
-      switch (key1->protocol)
+      switch (nat_proto)
        {
-         foreach_snat_protocol;
+         foreach_nat_protocol;
        default:
          nat_elog_info ("unknown protocol");
          return 1;
@@ -272,36 +281,61 @@ nat_ed_alloc_addr_and_port (snat_main_t * sm, u32 fib_index,
   return 1;
 }
 
+static_always_inline u32
+nat_outside_fib_index_lookup (snat_main_t * sm, ip4_address_t addr)
+{
+  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+  nat_outside_fib_t *outside_fib;
+  fib_prefix_t pfx = {
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_len = 32,
+    .fp_addr = {.ip4.as_u32 = addr.as_u32,}
+    ,
+  };
+  // TODO: multiple vrfs none can resolve addr
+  /* *INDENT-OFF* */
+  vec_foreach (outside_fib, sm->outside_fibs)
+    {
+      fei = fib_table_lookup (outside_fib->fib_index, &pfx);
+      if (FIB_NODE_INDEX_INVALID != fei)
+        {
+          if (fib_entry_get_resolving_interface (fei) != ~0)
+            {
+              return outside_fib->fib_index;
+            }
+        }
+    }
+  /* *INDENT-ON* */
+  return ~0;
+}
+
 static u32
 slow_path_ed (snat_main_t * sm,
              vlib_buffer_t * b,
+             ip4_address_t l_addr,
+             ip4_address_t r_addr,
+             u16 l_port,
+             u16 r_port,
+             u8 proto,
              u32 rx_fib_index,
-             clib_bihash_kv_16_8_t * kv,
              snat_session_t ** sessionp,
              vlib_node_runtime_t * node, u32 next, u32 thread_index, f64 now)
 {
-  snat_session_t *s = NULL;
-  snat_user_t *u = NULL;
-  snat_session_key_t key0, key1;
-  lb_nat_type_t lb = 0, is_sm = 0;
+
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  nat_ed_ses_key_t *key = (nat_ed_ses_key_t *) kv->key;
-  u32 proto = ip_proto_to_snat_proto (key->proto);
-  nat_outside_fib_t *outside_fib;
-  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
   clib_bihash_kv_16_8_t out2in_ed_kv;
-  bool out2in_ed_inserted = false;
-  u8 identity_nat;
-  fib_prefix_t pfx = {
-    .fp_proto = FIB_PROTOCOL_IP4,
-    .fp_len = 32,
-    .fp_addr = {
-               .ip4.as_u32 = key->r_addr.as_u32,
-               },
-  };
   nat44_is_idle_session_ctx_t ctx;
+  snat_session_key_t key0, key1;
+  ip4_address_t allocated_addr;
+  u16 allocated_port;
+  u32 tx_fib_index;
+  u8 identity_nat;
+
+  u32 nat_proto = ip_proto_to_nat_proto (proto);
+  snat_session_t *s = NULL;
+  lb_nat_type_t lb = 0;
 
-  if (PREDICT_TRUE (proto == SNAT_PROTOCOL_TCP))
+  if (PREDICT_TRUE (nat_proto == NAT_PROTOCOL_TCP))
     {
       if (PREDICT_FALSE
          (!tcp_flags_is_init
@@ -312,9 +346,10 @@ slow_path_ed (snat_main_t * sm,
        }
     }
 
-  if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
+  if (PREDICT_FALSE
+      (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
     {
-      if (!nat_global_lru_free_one (sm, thread_index, now))
+      if (!nat_lru_free_one (sm, thread_index, now))
        {
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
          nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
@@ -323,71 +358,53 @@ slow_path_ed (snat_main_t * sm,
        }
     }
 
-  key0.addr = key->l_addr;
-  key0.port = key->l_port;
-  key1.protocol = key0.protocol = proto;
+  key0.addr = l_addr;
+  key0.port = l_port;
+  key1.protocol = key0.protocol = nat_proto;
   key0.fib_index = rx_fib_index;
   key1.fib_index = sm->outside_fib_index;
+  tx_fib_index = sm->outside_fib_index;
 
   /* First try to match static mapping by local address and port */
   if (snat_static_mapping_match
       (sm, key0, &key1, 0, 0, 0, &lb, 0, &identity_nat))
     {
-      u =
-       nat_user_get_or_create (sm, &key->l_addr, rx_fib_index, thread_index);
-      if (!u)
-       {
-         nat_elog_warn ("create NAT user failed");
-         b->error = node->errors[NAT_IN2OUT_ED_ERROR_CANNOT_CREATE_USER];
-         goto drop;
-       }
-
-      s = nat_ed_session_alloc (sm, u, thread_index, now);
+      s = nat_ed_session_alloc (sm, thread_index, now, proto);
       if (!s)
        {
          nat_elog_warn ("create NAT session failed");
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
-         goto drop;
+         return NAT_NEXT_DROP;
        }
       switch (vec_len (sm->outside_fibs))
        {
        case 0:
-         s->out2in.fib_index = sm->outside_fib_index;
+         tx_fib_index = sm->outside_fib_index;
          break;
        case 1:
-         s->out2in.fib_index = sm->outside_fibs[0].fib_index;
+         tx_fib_index = sm->outside_fibs[0].fib_index;
          break;
        default:
-          /* *INDENT-OFF* */
-          vec_foreach (outside_fib, sm->outside_fibs)
-          {
-            fei = fib_table_lookup (outside_fib->fib_index, &pfx);
-            if (FIB_NODE_INDEX_INVALID != fei)
-              {
-                if (fib_entry_get_resolving_interface (fei) != ~0)
-                  {
-                    s->out2in.fib_index = outside_fib->fib_index;
-                    break;
-                  }
-              }
-          }
-          /* *INDENT-ON* */
+         tx_fib_index = nat_outside_fib_index_lookup (sm, r_addr);
          break;
        }
 
+      s->out2in.fib_index = tx_fib_index;
       /* Try to create dynamic translation */
-      if (nat_ed_alloc_addr_and_port (sm, rx_fib_index,
-                                     thread_index, key, &key1,
+      if (nat_ed_alloc_addr_and_port (sm, rx_fib_index, nat_proto,
+                                     thread_index, r_addr, r_port, proto,
                                      sm->port_per_thread,
                                      tsm->snat_thread_index, s,
-                                     &out2in_ed_kv))
+                                     &allocated_addr,
+                                     &allocated_port, &out2in_ed_kv))
        {
          nat_elog_notice ("addresses exhausted");
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
-         goto drop;
+         nat_ed_session_delete (sm, s, thread_index, 1);
+         return NAT_NEXT_DROP;
        }
-
-      out2in_ed_inserted = true;
+      key1.addr = allocated_addr;
+      key1.port = allocated_port;
     }
   else
     {
@@ -396,77 +413,54 @@ slow_path_ed (snat_main_t * sm,
          *sessionp = s;
          return next;
        }
-      is_sm = 1;
-      u =
-       nat_user_get_or_create (sm, &key->l_addr, rx_fib_index, thread_index);
-      if (!u)
-       {
-         nat_elog_warn ("create NAT user failed");
-         b->error = node->errors[NAT_IN2OUT_ED_ERROR_CANNOT_CREATE_USER];
-         goto drop;
-       }
-
-      s = nat_ed_session_alloc (sm, u, thread_index, now);
+      s = nat_ed_session_alloc (sm, thread_index, now, proto);
       if (!s)
        {
-         nat44_delete_user_with_no_session (sm, u, thread_index);
          nat_elog_warn ("create NAT session failed");
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
-         goto drop;
+         return NAT_NEXT_DROP;
        }
       switch (vec_len (sm->outside_fibs))
        {
        case 0:
-         s->out2in.fib_index = sm->outside_fib_index;
+         tx_fib_index = sm->outside_fib_index;
          break;
        case 1:
-         s->out2in.fib_index = sm->outside_fibs[0].fib_index;
+         tx_fib_index = sm->outside_fibs[0].fib_index;
          break;
        default:
-          /* *INDENT-OFF* */
-          vec_foreach (outside_fib, sm->outside_fibs)
-          {
-            fei = fib_table_lookup (outside_fib->fib_index, &pfx);
-            if (FIB_NODE_INDEX_INVALID != fei)
-              {
-                if (fib_entry_get_resolving_interface (fei) != ~0)
-                  {
-                    s->out2in.fib_index = outside_fib->fib_index;
-                    break;
-                  }
-              }
-          }
-          /* *INDENT-ON* */
+         tx_fib_index = nat_outside_fib_index_lookup (sm, r_addr);
          break;
        }
 
+      s->out2in.fib_index = tx_fib_index;
       s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
 
-
-      make_ed_kv (&out2in_ed_kv, &key1.addr, &key->r_addr, key->proto,
-                 s->out2in.fib_index, key1.port, key->r_port);
-      out2in_ed_kv.value = s - tsm->sessions;
+      make_ed_kv (&key1.addr, &r_addr, proto,
+                 s->out2in.fib_index, key1.port, r_port, thread_index,
+                 s - tsm->sessions, &out2in_ed_kv);
       if (clib_bihash_add_or_overwrite_stale_16_8
-         (&tsm->out2in_ed, &out2in_ed_kv, nat44_o2i_ed_is_idle_session_cb,
+         (&sm->out2in_ed, &out2in_ed_kv, nat44_o2i_ed_is_idle_session_cb,
           &ctx))
        nat_elog_notice ("out2in-ed key add failed");
-      out2in_ed_inserted = true;
     }
 
-  user_session_increment (sm, u, is_sm);
   if (lb)
     s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
   s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
-  s->ext_host_addr = key->r_addr;
-  s->ext_host_port = key->r_port;
+  s->ext_host_addr = r_addr;
+  s->ext_host_port = r_port;
   s->in2out = key0;
   s->out2in = key1;
+  s->out2in.fib_index = tx_fib_index;
   s->out2in.protocol = key0.protocol;
 
-  kv->value = s - tsm->sessions;
+  clib_bihash_kv_16_8_t in2out_ed_kv;
+  make_ed_kv (&l_addr, &r_addr, proto, rx_fib_index, l_port, r_port,
+             thread_index, s - tsm->sessions, &in2out_ed_kv);
   ctx.now = now;
   ctx.thread_index = thread_index;
-  if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, kv,
+  if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &in2out_ed_kv,
                                               nat44_i2o_ed_is_idle_session_cb,
                                               &ctx))
     nat_elog_notice ("in2out-ed key add failed");
@@ -495,22 +489,6 @@ slow_path_ed (snat_main_t * sm,
               thread_index, 0);
 
   return next;
-drop:
-  if (out2in_ed_inserted)
-    {
-      if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &out2in_ed_kv, 0))
-       nat_elog_notice ("out2in-ed key del failed");
-    }
-  if (s)
-    {
-      nat_free_session_data (sm, s, thread_index, 0);
-      nat44_ed_delete_session (sm, s, thread_index, 1);
-    }
-  if (u)
-    {
-      nat44_delete_user_with_no_session (sm, u, thread_index);
-    }
-  return NAT_NEXT_DROP;
 }
 
 static_always_inline int
@@ -519,16 +497,15 @@ nat44_ed_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
                        u32 rx_fib_index, u32 thread_index)
 {
   udp_header_t *udp = ip4_next_header (ip);
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
   clib_bihash_kv_16_8_t kv, value;
   snat_session_key_t key0, key1;
 
-  make_ed_kv (&kv, &ip->dst_address, &ip->src_address, ip->protocol,
-             sm->outside_fib_index, udp->dst_port, udp->src_port);
+  make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
+             sm->outside_fib_index, udp->dst_port, udp->src_port, ~0, ~0,
+             &kv);
 
-  /* NAT packet aimed at external address if */
-  /* has active sessions */
-  if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
+  /* NAT packet aimed at external address if has active sessions */
+  if (clib_bihash_search_16_8 (&sm->out2in_ed, &kv, &value))
     {
       key0.addr = ip->dst_address;
       key0.port = udp->dst_port;
@@ -553,7 +530,6 @@ nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
                                      u32 thread_index, f64 now,
                                      vlib_main_t * vm, vlib_buffer_t * b)
 {
-  nat_ed_ses_key_t key;
   clib_bihash_kv_16_8_t kv, value;
   snat_session_t *s = 0;
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
@@ -563,28 +539,27 @@ nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
 
   if (ip->protocol == IP_PROTOCOL_ICMP)
     {
-      key.as_u64[0] = key.as_u64[1] = 0;
-      if (get_icmp_i2o_ed_key (b, ip, &key))
+      if (get_icmp_i2o_ed_key (b, ip, 0, ~0, ~0, 0, 0, 0, &kv))
        return 0;
-      key.fib_index = 0;
-      kv.key[0] = key.as_u64[0];
-      kv.key[1] = key.as_u64[1];
     }
   else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
     {
-      make_ed_kv (&kv, &ip->src_address, &ip->dst_address, ip->protocol, 0,
+      make_ed_kv (&ip->src_address, &ip->dst_address, ip->protocol, 0,
                  vnet_buffer (b)->ip.reass.l4_src_port,
-                 vnet_buffer (b)->ip.reass.l4_dst_port);
+                 vnet_buffer (b)->ip.reass.l4_dst_port, ~0, ~0, &kv);
     }
   else
     {
-      make_ed_kv (&kv, &ip->src_address, &ip->dst_address, ip->protocol, 0, 0,
-                 0);
+      make_ed_kv (&ip->src_address, &ip->dst_address, ip->protocol, 0, 0,
+                 0, ~0, ~0, &kv);
     }
 
   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
     {
-      s = pool_elt_at_index (tsm->sessions, value.value);
+      ASSERT (thread_index == ed_value_get_thread_index (&value));
+      s =
+       pool_elt_at_index (tsm->sessions,
+                          ed_value_get_session_index (&value));
       if (is_fwd_bypass_session (s))
        {
          if (ip->protocol == IP_PROTOCOL_TCP)
@@ -610,7 +585,7 @@ nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
 
 static_always_inline int
 nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
-                                      u8 proto, u16 src_port, u16 dst_port,
+                                      u16 src_port, u16 dst_port,
                                       u32 thread_index, u32 rx_sw_if_index,
                                       u32 tx_sw_if_index)
 {
@@ -622,15 +597,18 @@ nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
   u32 tx_fib_index = ip4_fib_table_get_index_for_sw_if_index (tx_sw_if_index);
 
   /* src NAT check */
-  make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto, tx_fib_index,
-             src_port, dst_port);
-  if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
+  make_ed_kv (&ip->src_address, &ip->dst_address, ip->protocol,
+             tx_fib_index, src_port, dst_port, ~0, ~0, &kv);
+  if (!clib_bihash_search_16_8 (&sm->out2in_ed, &kv, &value))
     {
-      s = pool_elt_at_index (tsm->sessions, value.value);
+      ASSERT (thread_index == ed_value_get_thread_index (&value));
+      s =
+       pool_elt_at_index (tsm->sessions,
+                          ed_value_get_session_index (&value));
       if (nat44_is_ses_closed (s))
        {
          nat_free_session_data (sm, s, thread_index, 0);
-         nat44_delete_session (sm, s, thread_index);
+         nat_ed_session_delete (sm, s, thread_index, 1);
        }
       else
        s->flags |= SNAT_SESSION_FLAG_OUTPUT_FEATURE;
@@ -638,11 +616,14 @@ nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
     }
 
   /* dst NAT check */
-  make_ed_kv (&kv, &ip->dst_address, &ip->src_address, proto, rx_fib_index,
-             dst_port, src_port);
+  make_ed_kv (&ip->dst_address, &ip->src_address, ip->protocol,
+             rx_fib_index, dst_port, src_port, ~0, ~0, &kv);
   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
     {
-      s = pool_elt_at_index (tsm->sessions, value.value);
+      ASSERT (thread_index == ed_value_get_thread_index (&value));
+      s =
+       pool_elt_at_index (tsm->sessions,
+                          ed_value_get_session_index (&value));
       if (is_fwd_bypass_session (s))
        return 0;
 
@@ -669,29 +650,27 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
 {
   u32 sw_if_index;
   u32 rx_fib_index;
-  nat_ed_ses_key_t key;
   snat_session_t *s = 0;
   u8 dont_translate = 0;
   clib_bihash_kv_16_8_t kv, value;
   u32 next = ~0;
   int err;
+  u16 l_port = 0, r_port = 0;  // initialize to workaround gcc warning
+  vlib_main_t *vm = vlib_get_main ();
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
 
   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 
-  key.as_u64[0] = key.as_u64[1] = 0;
-  err = get_icmp_i2o_ed_key (b, ip, &key);
+  err =
+    get_icmp_i2o_ed_key (b, ip, rx_fib_index, ~0, ~0, p_proto, &l_port,
+                        &r_port, &kv);
   if (err != 0)
     {
       b->error = node->errors[err];
       next = NAT_NEXT_DROP;
       goto out;
     }
-  key.fib_index = rx_fib_index;
-
-  kv.key[0] = key.as_u64[0];
-  kv.key[1] = key.as_u64[1];
 
   if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
     {
@@ -699,7 +678,7 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
        {
          if (PREDICT_FALSE
              (nat44_ed_not_translate_output_feature
-              (sm, ip, key.proto, key.l_port, key.r_port, thread_index,
+              (sm, ip, l_port, r_port, thread_index,
                sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_TX])))
            {
              dont_translate = 1;
@@ -709,7 +688,7 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
       else
        {
          if (PREDICT_FALSE (nat44_ed_not_translate (sm, node, sw_if_index,
-                                                    ip, SNAT_PROTOCOL_ICMP,
+                                                    ip, NAT_PROTOCOL_ICMP,
                                                     rx_fib_index,
                                                     thread_index)))
            {
@@ -727,8 +706,10 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
          goto out;
        }
 
-      next = slow_path_ed (sm, b, rx_fib_index, &kv, &s, node, next,
-                          thread_index, vlib_time_now (sm->vlib_main));
+      next =
+       slow_path_ed (sm, b, ip->src_address, ip->dst_address, l_port, r_port,
+                     ip->protocol, rx_fib_index, &s, node, next,
+                     thread_index, vlib_time_now (vm));
 
       if (PREDICT_FALSE (next == NAT_NEXT_DROP))
        goto out;
@@ -754,10 +735,11 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
          goto out;
        }
 
-      s = pool_elt_at_index (tsm->sessions, value.value);
+      ASSERT (thread_index == ed_value_get_thread_index (&value));
+      s =
+       pool_elt_at_index (tsm->sessions,
+                          ed_value_get_session_index (&value));
     }
-
-  *p_proto = ip_proto_to_snat_proto (key.proto);
 out:
   if (s)
     *p_value = s->out2in;
@@ -782,23 +764,11 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
   snat_static_mapping_t *m;
   u32 old_addr, new_addr = 0;
   ip_csum_t sum;
-  snat_user_t *u;
-  dlist_elt_t *head, *elt;
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  u32 elt_index, head_index, ses_index;
   snat_session_t *s;
   u32 outside_fib_index = sm->outside_fib_index;
   int i;
   u8 is_sm = 0;
-  nat_outside_fib_t *outside_fib;
-  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
-  fib_prefix_t pfx = {
-    .fp_proto = FIB_PROTOCOL_IP4,
-    .fp_len = 32,
-    .fp_addr = {
-               .ip4.as_u32 = ip->dst_address.as_u32,
-               },
-  };
 
   switch (vec_len (sm->outside_fibs))
     {
@@ -809,35 +779,27 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
       outside_fib_index = sm->outside_fibs[0].fib_index;
       break;
     default:
-      /* *INDENT-OFF* */
-      vec_foreach (outside_fib, sm->outside_fibs)
-        {
-         fei = fib_table_lookup (outside_fib->fib_index, &pfx);
-         if (FIB_NODE_INDEX_INVALID != fei)
-           {
-             if (fib_entry_get_resolving_interface (fei) != ~0)
-               {
-                 outside_fib_index = outside_fib->fib_index;
-                 break;
-               }
-           }
-        }
-      /* *INDENT-ON* */
+      outside_fib_index = nat_outside_fib_index_lookup (sm, ip->dst_address);
       break;
     }
   old_addr = ip->src_address.as_u32;
 
-  make_ed_kv (&s_kv, &ip->src_address, &ip->dst_address, ip->protocol,
-             rx_fib_index, 0, 0);
+  make_ed_kv (&ip->src_address, &ip->dst_address, ip->protocol,
+             rx_fib_index, 0, 0, ~0, ~0, &s_kv);
 
   if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &s_kv, &s_value))
     {
-      s = pool_elt_at_index (tsm->sessions, s_value.value);
+      ASSERT (thread_index == ed_value_get_thread_index (&s_value));
+      s =
+       pool_elt_at_index (tsm->sessions,
+                          ed_value_get_session_index (&s_value));
       new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
     }
   else
     {
-      if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
+      if (PREDICT_FALSE
+         (nat44_ed_maximum_sessions_exceeded
+          (sm, rx_fib_index, thread_index)))
        {
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
          nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
@@ -845,15 +807,6 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
          return 0;
        }
 
-      u = nat_user_get_or_create (sm, &ip->src_address, rx_fib_index,
-                                 thread_index);
-      if (!u)
-       {
-         b->error = node->errors[NAT_IN2OUT_ED_ERROR_CANNOT_CREATE_USER];
-         nat_elog_warn ("create NAT user failed");
-         return 0;
-       }
-
       make_sm_kv (&kv, &ip->src_address, 0, rx_fib_index, 0);
 
       /* Try to find static mapping first */
@@ -864,47 +817,30 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
          is_sm = 1;
          goto create_ses;
        }
-      /* Fallback to 3-tuple key */
       else
        {
-         /* Choose same out address as for TCP/UDP session to same destination */
-         head_index = u->sessions_per_user_list_head_index;
-         head = pool_elt_at_index (tsm->list_pool, head_index);
-         elt_index = head->next;
-         if (PREDICT_FALSE (elt_index == ~0))
-           ses_index = ~0;
-         else
-           {
-             elt = pool_elt_at_index (tsm->list_pool, elt_index);
-             ses_index = elt->value;
-           }
-
-         while (ses_index != ~0)
-           {
-             s = pool_elt_at_index (tsm->sessions, ses_index);
-             elt_index = elt->next;
-             elt = pool_elt_at_index (tsm->list_pool, elt_index);
-             ses_index = elt->value;
-
-             if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
-               {
-                 new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
-
-                 make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address,
-                             ip->protocol, outside_fib_index, 0, 0);
-                 if (clib_bihash_search_16_8
-                     (&tsm->out2in_ed, &s_kv, &s_value))
-                   goto create_ses;
-
-                 break;
-               }
-           }
+         /* *INDENT-OFF* */
+         pool_foreach (s, tsm->sessions, {
+           if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
+             {
+               new_addr = ip->src_address.as_u32 = s->out2in.addr.as_u32;
+
+               make_ed_kv (&s->out2in.addr, &ip->dst_address, ip->protocol,
+                           outside_fib_index, 0, 0, ~0, ~0, &s_kv);
+               if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
+                 goto create_ses;
+
+               break;
+             }
+         });
+         /* *INDENT-ON* */
 
          for (i = 0; i < vec_len (sm->addresses); i++)
            {
-             make_ed_kv (&s_kv, &sm->addresses[i].addr, &ip->dst_address,
-                         ip->protocol, outside_fib_index, 0, 0);
-             if (clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
+             make_ed_kv (&sm->addresses[i].addr, &ip->dst_address,
+                         ip->protocol, outside_fib_index, 0, 0, ~0, ~0,
+                         &s_kv);
+             if (clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
                {
                  new_addr = ip->src_address.as_u32 =
                    sm->addresses[i].addr.as_u32;
@@ -915,11 +851,10 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
        }
 
     create_ses:
-      s = nat_ed_session_alloc (sm, u, thread_index, now);
+      s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
       if (!s)
        {
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_USER_SESS_EXCEEDED];
-         nat44_delete_user_with_no_session (sm, u, thread_index);
          nat_elog_warn ("create NAT session failed");
          return 0;
        }
@@ -934,19 +869,17 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
       s->in2out.port = s->out2in.port = ip->protocol;
       if (is_sm)
        s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
-      user_session_increment (sm, u, is_sm);
 
       /* Add to lookup tables */
-      make_ed_kv (&s_kv, &s->in2out.addr, &ip->dst_address, ip->protocol,
-                 rx_fib_index, 0, 0);
-      s_kv.value = s - tsm->sessions;
+      make_ed_kv (&s->in2out.addr, &ip->dst_address, ip->protocol,
+                 rx_fib_index, 0, 0, thread_index, s - tsm->sessions, &s_kv);
       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
        nat_elog_notice ("in2out key add failed");
 
-      make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address, ip->protocol,
-                 outside_fib_index, 0, 0);
-      s_kv.value = s - tsm->sessions;
-      if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
+      make_ed_kv (&s->out2in.addr, &ip->dst_address, ip->protocol,
+                 outside_fib_index, 0, 0, thread_index, s - tsm->sessions,
+                 &s_kv);
+      if (clib_bihash_add_del_16_8 (&sm->out2in_ed, &s_kv, 1))
        nat_elog_notice ("out2in key add failed");
     }
 
@@ -1053,9 +986,9 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
 
          udp0 = ip4_next_header (ip0);
          tcp0 = (tcp_header_t *) udp0;
-         proto0 = ip_proto_to_snat_proto (ip0->protocol);
+         proto0 = ip_proto_to_nat_proto (ip0->protocol);
 
-         if (PREDICT_FALSE (proto0 == ~0))
+         if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
            {
              next0 = def_slow;
              goto trace0;
@@ -1068,16 +1001,16 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
                goto trace0;
            }
 
-         if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+         if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
            {
              next0 = def_slow;
              goto trace0;
            }
 
-         make_ed_kv (&kv0, &ip0->src_address, &ip0->dst_address,
+         make_ed_kv (&ip0->src_address, &ip0->dst_address,
                      ip0->protocol, rx_fib_index0,
                      vnet_buffer (b0)->ip.reass.l4_src_port,
-                     vnet_buffer (b0)->ip.reass.l4_dst_port);
+                     vnet_buffer (b0)->ip.reass.l4_dst_port, ~0, ~0, &kv0);
 
          // lookup for session
          if (clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
@@ -1086,11 +1019,14 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
              next0 = def_slow;
              goto trace0;
            }
-         s0 = pool_elt_at_index (tsm->sessions, value0.value);
+         ASSERT (thread_index == ed_value_get_thread_index (&value0));
+         s0 =
+           pool_elt_at_index (tsm->sessions,
+                              ed_value_get_session_index (&value0));
 
-         if (s0->tcp_close_timestamp)
+         if (s0->tcp_closed_timestamp)
            {
-             if (now >= s0->tcp_close_timestamp)
+             if (now >= s0->tcp_closed_timestamp)
                {
                  // session is closed, go slow path
                  next0 = def_slow;
@@ -1111,7 +1047,7 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
          if (now >= sess_timeout_time)
            {
              nat_free_session_data (sm, s0, thread_index, 0);
-             nat44_delete_session (sm, s0, thread_index);
+             nat_ed_session_delete (sm, s0, thread_index, 1);
              // session is closed, go slow path
              next0 = def_slow;
              goto trace0;
@@ -1135,7 +1071,7 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
 
          old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
 
-         if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
+         if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
            {
              if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
                {
@@ -1161,7 +1097,7 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
                      tcp0->dst_port = s0->ext_host_port;
                      ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
                    }
-                 mss_clamping (sm, tcp0, &sum0);
+                 mss_clamping (sm->mss_clamping, tcp0, &sum0);
                  tcp0->checksum = ip_csum_fold (sum0);
                }
              tcp_packets++;
@@ -1335,9 +1271,9 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
          udp0 = ip4_next_header (ip0);
          tcp0 = (tcp_header_t *) udp0;
          icmp0 = (icmp46_header_t *) udp0;
-         proto0 = ip_proto_to_snat_proto (ip0->protocol);
+         proto0 = ip_proto_to_nat_proto (ip0->protocol);
 
-         if (PREDICT_FALSE (proto0 == ~0))
+         if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
            {
              s0 = nat44_ed_in2out_unknown_proto (sm, b0, ip0,
                                                  rx_fib_index0,
@@ -1350,7 +1286,7 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
              goto trace0;
            }
 
-         if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
+         if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
            {
              next0 = icmp_in2out_ed_slow_path
                (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
@@ -1359,20 +1295,22 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
              goto trace0;
            }
 
-         // move down
-         make_ed_kv (&kv0, &ip0->src_address, &ip0->dst_address,
+         make_ed_kv (&ip0->src_address, &ip0->dst_address,
                      ip0->protocol, rx_fib_index0,
                      vnet_buffer (b0)->ip.reass.l4_src_port,
-                     vnet_buffer (b0)->ip.reass.l4_dst_port);
+                     vnet_buffer (b0)->ip.reass.l4_dst_port, ~0, ~0, &kv0);
 
          if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv0, &value0))
            {
-             s0 = pool_elt_at_index (tsm->sessions, value0.value);
+             ASSERT (thread_index == ed_value_get_thread_index (&value0));
+             s0 =
+               pool_elt_at_index (tsm->sessions,
+                                  ed_value_get_session_index (&value0));
 
-             if (s0->tcp_close_timestamp && now >= s0->tcp_close_timestamp)
+             if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
                {
                  nat_free_session_data (sm, s0, thread_index, 0);
-                 nat44_delete_session (sm, s0, thread_index);
+                 nat_ed_session_delete (sm, s0, thread_index, 1);
                  s0 = NULL;
                }
            }
@@ -1383,10 +1321,9 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
                {
                  if (PREDICT_FALSE
                      (nat44_ed_not_translate_output_feature
-                      (sm, ip0, ip0->protocol,
-                       vnet_buffer (b0)->ip.reass.l4_src_port,
-                       vnet_buffer (b0)->ip.reass.l4_dst_port,
-                       thread_index, sw_if_index0,
+                      (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
+                       vnet_buffer (b0)->ip.reass.l4_dst_port, thread_index,
+                       sw_if_index0,
                        vnet_buffer (b0)->sw_if_index[VLIB_TX])))
                    goto trace0;
 
@@ -1395,7 +1332,7 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
                   * be able to use dhcp client on the outside interface
                   */
                  if (PREDICT_FALSE
-                     (proto0 == SNAT_PROTOCOL_UDP
+                     (proto0 == NAT_PROTOCOL_UDP
                       && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
                           clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_server))
                       && ip0->dst_address.as_u32 == 0xffffffff))
@@ -1410,8 +1347,12 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
                    goto trace0;
                }
 
-             next0 = slow_path_ed (sm, b0, rx_fib_index0, &kv0, &s0, node,
-                                   next0, thread_index, now);
+             next0 =
+               slow_path_ed (sm, b0, ip0->src_address, ip0->dst_address,
+                             vnet_buffer (b0)->ip.reass.l4_src_port,
+                             vnet_buffer (b0)->ip.reass.l4_dst_port,
+                             ip0->protocol, rx_fib_index0, &s0, node, next0,
+                             thread_index, now);
 
              if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
                goto trace0;
@@ -1439,7 +1380,7 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
 
          old_port0 = vnet_buffer (b0)->ip.reass.l4_src_port;
 
-         if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
+         if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
            {
              if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
                {
@@ -1465,7 +1406,7 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
                      tcp0->dst_port = s0->ext_host_port;
                      ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
                    }
-                 mss_clamping (sm, tcp0, &sum0);
+                 mss_clamping (sm->mss_clamping, tcp0, &sum0);
                  tcp0->checksum = ip_csum_fold (sum0);
                }
              tcp_packets++;
@@ -1650,7 +1591,8 @@ format_nat_pre_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 *);
   nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
-  return format (s, "in2out next_index %d", t->next_index);
+  return format (s, "in2out next_index %d arc_next_index %d", t->next_index,
+                t->arc_next_index);
 }
 
 VLIB_NODE_FN (nat_pre_in2out_node)