nat: use SVR
[vpp.git] / src / plugins / nat / out2in.c
index b743c08..e9ca88f 100755 (executable)
 #include <vnet/fib/ip4_fib.h>
 #include <nat/nat.h>
 #include <nat/nat_ipfix_logging.h>
-#include <nat/nat_reass.h>
 #include <nat/nat_inlines.h>
+#include <nat/nat44_inlines.h>
 #include <nat/nat_syslog.h>
+#include <nat/nat_ha.h>
 
 #include <vppinfra/hash.h>
 #include <vppinfra/error.h>
@@ -106,7 +107,6 @@ typedef enum
   SNAT_OUT2IN_NEXT_DROP,
   SNAT_OUT2IN_NEXT_LOOKUP,
   SNAT_OUT2IN_NEXT_ICMP_ERROR,
-  SNAT_OUT2IN_NEXT_REASS,
   SNAT_OUT2IN_N_NEXT,
 } snat_out2in_next_t;
 
@@ -128,7 +128,7 @@ nat44_o2i_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
     {
       s_kv.key = s->in2out.as_u64;
       if (clib_bihash_add_del_8_8 (&tsm->in2out, &s_kv, 0))
-       nat_log_warn ("out2in key del failed");
+       nat_elog_warn ("out2in key del failed");
 
       snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
                                           s->in2out.addr.as_u32,
@@ -143,6 +143,10 @@ nat44_o2i_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
                               &s->out2in.addr, s->out2in.port,
                               s->in2out.protocol);
 
+      nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
+                  s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
+                  ctx->thread_index);
+
       if (!snat_is_session_static (s))
        snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
                                            &s->out2in);
@@ -184,10 +188,13 @@ create_session_for_static_mapping (snat_main_t * sm,
   udp_header_t *udp0;
   nat44_is_idle_session_ctx_t ctx0;
 
+  nat44_session_try_cleanup (&in2out.addr, in2out.fib_index, thread_index,
+                            now);
+
   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
     {
       b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_log_notice ("maximum sessions exceeded");
+      nat_elog_notice ("maximum sessions exceeded");
       return 0;
     }
 
@@ -198,15 +205,15 @@ create_session_for_static_mapping (snat_main_t * sm,
     nat_user_get_or_create (sm, &in2out.addr, in2out.fib_index, thread_index);
   if (!u)
     {
-      nat_log_warn ("create NAT user failed");
+      nat_elog_warn ("create NAT user failed");
       return 0;
     }
 
-  s = nat_session_alloc_or_recycle (sm, u, thread_index);
+  s = nat_session_alloc_or_recycle (sm, u, thread_index, now);
   if (!s)
     {
       nat44_delete_user_with_no_session (sm, u, thread_index);
-      nat_log_warn ("create NAT session failed");
+      nat_elog_warn ("create NAT session failed");
       return 0;
     }
 
@@ -226,14 +233,14 @@ create_session_for_static_mapping (snat_main_t * sm,
   if (clib_bihash_add_or_overwrite_stale_8_8
       (&sm->per_thread_data[thread_index].in2out, &kv0,
        nat44_i2o_is_idle_session_cb, &ctx0))
-    nat_log_notice ("in2out key add failed");
+    nat_elog_notice ("in2out key add failed");
 
   kv0.key = s->out2in.as_u64;
 
   if (clib_bihash_add_or_overwrite_stale_8_8
       (&sm->per_thread_data[thread_index].out2in, &kv0,
        nat44_o2i_is_idle_session_cb, &ctx0))
-    nat_log_notice ("out2in key add failed");
+    nat_elog_notice ("out2in key add failed");
 
   /* log NAT event */
   snat_ipfix_logging_nat44_ses_create (thread_index,
@@ -247,12 +254,18 @@ create_session_for_static_mapping (snat_main_t * sm,
                           &s->in2out.addr, s->in2out.port, &s->out2in.addr,
                           s->out2in.port, s->in2out.protocol);
 
+  nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
+              s->out2in.port, &s->ext_host_addr, s->ext_host_port,
+              &s->ext_host_nat_addr, s->ext_host_nat_port,
+              s->in2out.protocol, s->in2out.fib_index, s->flags,
+              thread_index, 0);
+
   return s;
 }
 
 #ifndef CLIB_MARCH_VARIANT
 static_always_inline
-  snat_out2in_error_t icmp_get_key (ip4_header_t * ip0,
+  snat_out2in_error_t icmp_get_key (vlib_buffer_t * b, ip4_header_t * ip0,
                                    snat_session_key_t * p_key0)
 {
   icmp46_header_t *icmp0;
@@ -265,11 +278,12 @@ static_always_inline
   icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
   echo0 = (icmp_echo_header_t *) (icmp0 + 1);
 
-  if (!icmp_is_error_message (icmp0))
+  if (!icmp_type_is_error_message
+      (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
     {
       key0.protocol = SNAT_PROTOCOL_ICMP;
       key0.addr = ip0->dst_address;
-      key0.port = echo0->identifier;
+      key0.port = vnet_buffer (b)->ip.reass.l4_src_port;       // TODO should this be dst port?
     }
   else
     {
@@ -317,7 +331,6 @@ icmp_match_out2in_slow (snat_main_t * sm, vlib_node_runtime_t * node,
                        snat_session_key_t * p_value,
                        u8 * p_dont_translate, void *d, void *e)
 {
-  icmp46_header_t *icmp0;
   u32 sw_if_index0;
   u32 rx_fib_index0;
   snat_session_key_t key0;
@@ -330,13 +343,12 @@ icmp_match_out2in_slow (snat_main_t * sm, vlib_node_runtime_t * node,
   int err;
   u8 identity_nat;
 
-  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
   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);
 
   key0.protocol = 0;
 
-  err = icmp_get_key (ip0, &key0);
+  err = icmp_get_key (b0, ip0, &key0);
   if (err != -1)
     {
       b0->error = node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
@@ -375,9 +387,11 @@ icmp_match_out2in_slow (snat_main_t * sm, vlib_node_runtime_t * node,
            }
        }
 
-      if (PREDICT_FALSE (icmp0->type != ICMP4_echo_reply &&
-                        (icmp0->type != ICMP4_echo_request
-                         || !is_addr_only)))
+      if (PREDICT_FALSE
+         (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
+          ICMP4_echo_reply
+          && (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
+              ICMP4_echo_request || !is_addr_only)))
        {
          b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
          next0 = SNAT_OUT2IN_NEXT_DROP;
@@ -402,9 +416,13 @@ icmp_match_out2in_slow (snat_main_t * sm, vlib_node_runtime_t * node,
     }
   else
     {
-      if (PREDICT_FALSE (icmp0->type != ICMP4_echo_reply &&
-                        icmp0->type != ICMP4_echo_request &&
-                        !icmp_is_error_message (icmp0)))
+      if (PREDICT_FALSE
+         (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
+          ICMP4_echo_reply
+          && vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
+          ICMP4_echo_request
+          && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
+                                          reass.icmp_type_or_tcp_flags)))
        {
          b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
          next0 = SNAT_OUT2IN_NEXT_DROP;
@@ -447,7 +465,6 @@ icmp_match_out2in_fast (snat_main_t * sm, vlib_node_runtime_t * node,
                        snat_session_key_t * p_value,
                        u8 * p_dont_translate, void *d, void *e)
 {
-  icmp46_header_t *icmp0;
   u32 sw_if_index0;
   u32 rx_fib_index0;
   snat_session_key_t key0;
@@ -457,11 +474,10 @@ icmp_match_out2in_fast (snat_main_t * sm, vlib_node_runtime_t * node,
   u32 next0 = ~0;
   int err;
 
-  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
   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);
 
-  err = icmp_get_key (ip0, &key0);
+  err = icmp_get_key (b0, ip0, &key0);
   if (err != -1)
     {
       b0->error = node->errors[err];
@@ -484,9 +500,12 @@ icmp_match_out2in_fast (snat_main_t * sm, vlib_node_runtime_t * node,
       goto out;
     }
 
-  if (PREDICT_FALSE (icmp0->type != ICMP4_echo_reply &&
-                    (icmp0->type != ICMP4_echo_request || !is_addr_only) &&
-                    !icmp_is_error_message (icmp0)))
+  if (PREDICT_FALSE
+      (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags != ICMP4_echo_reply
+       && (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
+          ICMP4_echo_request || !is_addr_only)
+       && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
+                                      reass.icmp_type_or_tcp_flags)))
     {
       b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
       next0 = SNAT_OUT2IN_NEXT_DROP;
@@ -560,72 +579,78 @@ icmp_out2in (snat_main_t * sm,
                         dst_address /* changed member */ );
   ip0->checksum = ip_csum_fold (sum0);
 
-  if (icmp0->checksum == 0)
-    icmp0->checksum = 0xffff;
 
-  if (!icmp_is_error_message (icmp0))
+  if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
     {
-      new_id0 = sm0.port;
-      if (PREDICT_FALSE (new_id0 != echo0->identifier))
+      if (icmp0->checksum == 0)
+       icmp0->checksum = 0xffff;
+
+      if (!icmp_type_is_error_message (icmp0->type))
        {
-         old_id0 = echo0->identifier;
          new_id0 = sm0.port;
-         echo0->identifier = new_id0;
-
-         sum0 = icmp0->checksum;
-         sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
-                                identifier /* changed member */ );
-         icmp0->checksum = ip_csum_fold (sum0);
+         if (PREDICT_FALSE (new_id0 != echo0->identifier))
+           {
+             old_id0 = echo0->identifier;
+             new_id0 = sm0.port;
+             echo0->identifier = new_id0;
+
+             sum0 = icmp0->checksum;
+             sum0 =
+               ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+                               identifier /* changed member */ );
+             icmp0->checksum = ip_csum_fold (sum0);
+           }
        }
-    }
-  else
-    {
-      inner_ip0 = (ip4_header_t *) (echo0 + 1);
-      l4_header = ip4_next_header (inner_ip0);
-
-      if (!ip4_header_checksum_is_valid (inner_ip0))
+      else
        {
-         next0 = SNAT_OUT2IN_NEXT_DROP;
-         goto out;
-       }
-
-      old_addr0 = inner_ip0->src_address.as_u32;
-      inner_ip0->src_address = sm0.addr;
-      new_addr0 = inner_ip0->src_address.as_u32;
-
-      sum0 = icmp0->checksum;
-      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
-                            src_address /* changed member */ );
-      icmp0->checksum = ip_csum_fold (sum0);
+         inner_ip0 = (ip4_header_t *) (echo0 + 1);
+         l4_header = ip4_next_header (inner_ip0);
 
-      switch (protocol)
-       {
-       case SNAT_PROTOCOL_ICMP:
-         inner_icmp0 = (icmp46_header_t *) l4_header;
-         inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
+         if (!ip4_header_checksum_is_valid (inner_ip0))
+           {
+             next0 = SNAT_OUT2IN_NEXT_DROP;
+             goto out;
+           }
 
-         old_id0 = inner_echo0->identifier;
-         new_id0 = sm0.port;
-         inner_echo0->identifier = new_id0;
+         old_addr0 = inner_ip0->src_address.as_u32;
+         inner_ip0->src_address = sm0.addr;
+         new_addr0 = inner_ip0->src_address.as_u32;
 
          sum0 = icmp0->checksum;
-         sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
-                                identifier);
+         sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                                src_address /* changed member */ );
          icmp0->checksum = ip_csum_fold (sum0);
-         break;
-       case SNAT_PROTOCOL_UDP:
-       case SNAT_PROTOCOL_TCP:
-         old_id0 = ((tcp_udp_header_t *) l4_header)->src_port;
-         new_id0 = sm0.port;
-         ((tcp_udp_header_t *) l4_header)->src_port = new_id0;
 
-         sum0 = icmp0->checksum;
-         sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
-                                src_port);
-         icmp0->checksum = ip_csum_fold (sum0);
-         break;
-       default:
-         ASSERT (0);
+         switch (protocol)
+           {
+           case SNAT_PROTOCOL_ICMP:
+             inner_icmp0 = (icmp46_header_t *) l4_header;
+             inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
+
+             old_id0 = inner_echo0->identifier;
+             new_id0 = sm0.port;
+             inner_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);
+             break;
+           case SNAT_PROTOCOL_UDP:
+           case SNAT_PROTOCOL_TCP:
+             old_id0 = ((tcp_udp_header_t *) l4_header)->src_port;
+             new_id0 = sm0.port;
+             ((tcp_udp_header_t *) l4_header)->src_port = new_id0;
+
+             sum0 = icmp0->checksum;
+             sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
+                                    src_port);
+             icmp0->checksum = ip_csum_fold (sum0);
+             break;
+           default:
+             ASSERT (0);
+           }
        }
     }
 
@@ -653,7 +678,7 @@ icmp_out2in_slow_path (snat_main_t * sm,
       /* Accounting */
       nat44_session_update_counters (s0, now,
                                     vlib_buffer_length_in_chain
-                                    (sm->vlib_main, b0));
+                                    (sm->vlib_main, b0), thread_index);
       /* Per-user LRU list maintenance */
       nat44_session_update_lru (sm, s0, thread_index);
     }
@@ -801,13 +826,6 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
              goto trace0;
            }
 
-         if (PREDICT_FALSE (ip4_is_fragment (ip0)))
-           {
-             next0 = SNAT_OUT2IN_NEXT_REASS;
-             fragments++;
-             goto trace0;
-           }
-
          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
            {
              next0 = icmp_out2in_slow_path
@@ -818,7 +836,7 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            }
 
          key0.addr = ip0->dst_address;
-         key0.port = udp0->dst_port;
+         key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
          key0.protocol = proto0;
          key0.fib_index = rx_fib_index0;
 
@@ -836,10 +854,11 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
                   * Send DHCP packets to the ipv4 stack, or we won't
                   * be able to use dhcp client on the outside interface
                   */
-                 if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
-                                    && (udp0->dst_port ==
-                                        clib_host_to_net_u16
-                                        (UDP_DST_PORT_dhcp_to_client))))
+                 if (PREDICT_FALSE
+                     (proto0 == SNAT_PROTOCOL_UDP
+                      && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
+                          clib_host_to_net_u16
+                          (UDP_DST_PORT_dhcp_to_client))))
                    {
                      vnet_feature_next (&next0, b0);
                      goto trace0;
@@ -884,33 +903,47 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
 
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
-             old_port0 = tcp0->dst_port;
-             tcp0->dst_port = s0->in2out.port;
-             new_port0 = tcp0->dst_port;
-
-             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);
+             if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
+               {
+                 old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
+                 new_port0 = udp0->dst_port = s0->in2out.port;
+                 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);
+               }
              tcp_packets++;
            }
          else
            {
-             old_port0 = udp0->dst_port;
-             udp0->dst_port = s0->in2out.port;
-             udp0->checksum = 0;
+             if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
+               {
+                 old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
+                 new_port0 = udp0->dst_port = s0->in2out.port;
+                 if (PREDICT_FALSE (udp0->checksum))
+                   {
+                     sum0 = udp0->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 */ );
+                     udp0->checksum = ip_csum_fold (sum0);
+                   }
+               }
              udp_packets++;
            }
 
          /* Accounting */
          nat44_session_update_counters (s0, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b0));
+                                        vlib_buffer_length_in_chain (vm, b0),
+                                        thread_index);
          /* Per-user LRU list maintenance */
          nat44_session_update_lru (sm, s0, thread_index);
        trace0:
@@ -967,13 +1000,6 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
              goto trace1;
            }
 
-         if (PREDICT_FALSE (ip4_is_fragment (ip1)))
-           {
-             next1 = SNAT_OUT2IN_NEXT_REASS;
-             fragments++;
-             goto trace1;
-           }
-
          if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
            {
              next1 = icmp_out2in_slow_path
@@ -984,7 +1010,7 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            }
 
          key1.addr = ip1->dst_address;
-         key1.port = udp1->dst_port;
+         key1.port = vnet_buffer (b1)->ip.reass.l4_dst_port;
          key1.protocol = proto1;
          key1.fib_index = rx_fib_index1;
 
@@ -1002,10 +1028,11 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
                   * Send DHCP packets to the ipv4 stack, or we won't
                   * be able to use dhcp client on the outside interface
                   */
-                 if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_UDP
-                                    && (udp1->dst_port ==
-                                        clib_host_to_net_u16
-                                        (UDP_DST_PORT_dhcp_to_client))))
+                 if (PREDICT_FALSE
+                     (proto1 == SNAT_PROTOCOL_UDP
+                      && (vnet_buffer (b1)->ip.reass.l4_dst_port ==
+                          clib_host_to_net_u16
+                          (UDP_DST_PORT_dhcp_to_client))))
                    {
                      vnet_feature_next (&next1, b1);
                      goto trace1;
@@ -1050,33 +1077,51 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
 
          if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
            {
-             old_port1 = tcp1->dst_port;
-             tcp1->dst_port = s1->in2out.port;
-             new_port1 = tcp1->dst_port;
-
-             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);
+             if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment)
+               {
+                 old_port1 = vnet_buffer (b1)->ip.reass.l4_dst_port;
+                 new_port1 = udp1->dst_port = s1->in2out.port;
+
+                 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);
+               }
              tcp_packets++;
            }
          else
            {
-             old_port1 = udp1->dst_port;
-             udp1->dst_port = s1->in2out.port;
-             udp1->checksum = 0;
+             if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment)
+               {
+                 old_port1 = vnet_buffer (b1)->ip.reass.l4_dst_port;
+                 new_port1 = udp1->dst_port = s1->in2out.port;
+                 if (PREDICT_FALSE (udp1->checksum))
+                   {
+
+                     sum1 = udp1->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 */ );
+                     udp1->checksum = ip_csum_fold (sum1);
+                   }
+               }
              udp_packets++;
            }
 
          /* Accounting */
          nat44_session_update_counters (s1, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b1));
+                                        vlib_buffer_length_in_chain (vm, b1),
+                                        thread_index);
          /* Per-user LRU list maintenance */
          nat44_session_update_lru (sm, s1, thread_index);
        trace1:
@@ -1170,13 +1215,6 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
              goto trace00;
            }
 
-         if (PREDICT_FALSE (ip4_is_fragment (ip0)))
-           {
-             next0 = SNAT_OUT2IN_NEXT_REASS;
-             fragments++;
-             goto trace00;
-           }
-
          if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
            {
              next0 = icmp_out2in_slow_path
@@ -1187,7 +1225,7 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
            }
 
          key0.addr = ip0->dst_address;
-         key0.port = udp0->dst_port;
+         key0.port = vnet_buffer (b0)->ip.reass.l4_dst_port;
          key0.protocol = proto0;
          key0.fib_index = rx_fib_index0;
 
@@ -1205,10 +1243,11 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
                   * Send DHCP packets to the ipv4 stack, or we won't
                   * be able to use dhcp client on the outside interface
                   */
-                 if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
-                                    && (udp0->dst_port ==
-                                        clib_host_to_net_u16
-                                        (UDP_DST_PORT_dhcp_to_client))))
+                 if (PREDICT_FALSE
+                     (proto0 == SNAT_PROTOCOL_UDP
+                      && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
+                          clib_host_to_net_u16
+                          (UDP_DST_PORT_dhcp_to_client))))
                    {
                      vnet_feature_next (&next0, b0);
                      goto trace00;
@@ -1253,33 +1292,48 @@ VLIB_NODE_FN (snat_out2in_node) (vlib_main_t * vm,
 
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
-             old_port0 = tcp0->dst_port;
-             tcp0->dst_port = s0->in2out.port;
-             new_port0 = tcp0->dst_port;
-
-             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);
+             if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
+               {
+                 old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
+                 new_port0 = udp0->dst_port = s0->in2out.port;
+
+                 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);
+               }
              tcp_packets++;
            }
          else
            {
-             old_port0 = udp0->dst_port;
-             udp0->dst_port = s0->in2out.port;
-             udp0->checksum = 0;
+             if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
+               {
+                 old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
+                 new_port0 = udp0->dst_port = s0->in2out.port;
+                 if (PREDICT_FALSE (udp0->checksum))
+                   {
+                     sum0 = udp0->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 */ );
+                     udp0->checksum = ip_csum_fold (sum0);
+                   }
+               }
              udp_packets++;
            }
 
          /* Accounting */
          nat44_session_update_counters (s0, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b0));
+                                        vlib_buffer_length_in_chain (vm, b0),
+                                        thread_index);
          /* Per-user LRU list maintenance */
          nat44_session_update_lru (sm, s0, thread_index);
        trace00:
@@ -1345,340 +1399,6 @@ VLIB_REGISTER_NODE (snat_out2in_node) = {
     [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
-  },
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FN (nat44_out2in_reass_node) (vlib_main_t * vm,
-                                       vlib_node_runtime_t * node,
-                                       vlib_frame_t * frame)
-{
-  u32 n_left_from, *from, *to_next;
-  snat_out2in_next_t next_index;
-  u32 pkts_processed = 0, cached_fragments = 0;
-  snat_main_t *sm = &snat_main;
-  f64 now = vlib_time_now (vm);
-  u32 thread_index = vm->thread_index;
-  snat_main_per_thread_data_t *per_thread_data =
-    &sm->per_thread_data[thread_index];
-  u32 *fragments_to_drop = 0;
-  u32 *fragments_to_loopback = 0;
-
-  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, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
-         vlib_buffer_t *b0;
-         u32 next0;
-         u8 cached0 = 0;
-         ip4_header_t *ip0;
-         nat_reass_ip4_t *reass0;
-         udp_header_t *udp0;
-         tcp_header_t *tcp0;
-         icmp46_header_t *icmp0;
-         snat_session_key_t key0, sm0;
-         clib_bihash_kv_8_8_t kv0, value0;
-         snat_session_t *s0 = 0;
-         u16 old_port0, new_port0;
-         ip_csum_t sum0;
-         u8 identity_nat0;
-
-         /* 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_OUT2IN_NEXT_LOOKUP;
-
-         sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-         rx_fib_index0 =
-           fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
-                                                sw_if_index0);
-
-         if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
-           {
-             next0 = SNAT_OUT2IN_NEXT_DROP;
-             b0->error = node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT];
-             goto trace0;
-           }
-
-         ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
-         udp0 = ip4_next_header (ip0);
-         tcp0 = (tcp_header_t *) udp0;
-         icmp0 = (icmp46_header_t *) udp0;
-         proto0 = ip_proto_to_snat_proto (ip0->protocol);
-
-         reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
-                                                ip0->dst_address,
-                                                ip0->fragment_id,
-                                                ip0->protocol,
-                                                1, &fragments_to_drop);
-
-         if (PREDICT_FALSE (!reass0))
-           {
-             next0 = SNAT_OUT2IN_NEXT_DROP;
-             b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_REASS];
-             nat_log_notice ("maximum reassemblies exceeded");
-             goto trace0;
-           }
-
-         if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
-           {
-             if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
-               {
-                 next0 = icmp_out2in_slow_path
-                   (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
-                    next0, now, thread_index, &s0);
-
-                 if (PREDICT_TRUE (next0 != SNAT_OUT2IN_NEXT_DROP))
-                   {
-                     if (s0)
-                       reass0->sess_index = s0 - per_thread_data->sessions;
-                     else
-                       reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
-                     reass0->thread_index = thread_index;
-                     nat_ip4_reass_get_frags (reass0,
-                                              &fragments_to_loopback);
-                   }
-
-                 goto trace0;
-               }
-
-             key0.addr = ip0->dst_address;
-             key0.port = udp0->dst_port;
-             key0.protocol = proto0;
-             key0.fib_index = rx_fib_index0;
-             kv0.key = key0.as_u64;
-
-             if (clib_bihash_search_8_8
-                 (&per_thread_data->out2in, &kv0, &value0))
-               {
-                 /* Try to match static mapping by external address and port,
-                    destination address and port in packet */
-                 if (snat_static_mapping_match
-                     (sm, key0, &sm0, 1, 0, 0, 0, 0, &identity_nat0))
-                   {
-                     /*
-                      * Send DHCP packets to the ipv4 stack, or we won't
-                      * be able to use dhcp client on the outside interface
-                      */
-                     if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP
-                                        && (udp0->dst_port
-                                            ==
-                                            clib_host_to_net_u16
-                                            (UDP_DST_PORT_dhcp_to_client))))
-                       {
-                         vnet_feature_next (&next0, b0);
-                         goto trace0;
-                       }
-
-                     if (!sm->forwarding_enabled)
-                       {
-                         b0->error =
-                           node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-                         next0 = SNAT_OUT2IN_NEXT_DROP;
-                       }
-                     else
-                       {
-                         reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
-                         nat_ip4_reass_get_frags (reass0,
-                                                  &fragments_to_loopback);
-                       }
-                     goto trace0;
-                   }
-
-                 if (PREDICT_FALSE (identity_nat0))
-                   goto trace0;
-
-                 /* Create session initiated by host from external network */
-                 s0 =
-                   create_session_for_static_mapping (sm, b0, sm0, key0,
-                                                      node, thread_index,
-                                                      now);
-                 if (!s0)
-                   {
-                     b0->error =
-                       node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-                     next0 = SNAT_OUT2IN_NEXT_DROP;
-                     goto trace0;
-                   }
-                 reass0->sess_index = s0 - per_thread_data->sessions;
-                 reass0->thread_index = thread_index;
-               }
-             else
-               {
-                 s0 = pool_elt_at_index (per_thread_data->sessions,
-                                         value0.value);
-                 reass0->sess_index = value0.value;
-               }
-             nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
-           }
-         else
-           {
-             if (reass0->flags & NAT_REASS_FLAG_ED_DONT_TRANSLATE)
-               goto trace0;
-             if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
-               {
-                 if (nat_ip4_reass_add_fragment
-                     (thread_index, reass0, bi0, &fragments_to_drop))
-                   {
-                     b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_FRAG];
-                     nat_log_notice
-                       ("maximum fragments per reassembly exceeded");
-                     next0 = SNAT_OUT2IN_NEXT_DROP;
-                     goto trace0;
-                   }
-                 cached0 = 1;
-                 goto trace0;
-               }
-             s0 = pool_elt_at_index (per_thread_data->sessions,
-                                     reass0->sess_index);
-           }
-
-         old_addr0 = ip0->dst_address.as_u32;
-         ip0->dst_address = s0->in2out.addr;
-         new_addr0 = ip0->dst_address.as_u32;
-         vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
-
-         sum0 = ip0->checksum;
-         sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-                                ip4_header_t,
-                                dst_address /* changed member */ );
-         ip0->checksum = ip_csum_fold (sum0);
-
-         if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
-           {
-             if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
-               {
-                 old_port0 = tcp0->dst_port;
-                 tcp0->dst_port = s0->in2out.port;
-                 new_port0 = tcp0->dst_port;
-
-                 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->dst_port;
-                 udp0->dst_port = s0->in2out.port;
-                 udp0->checksum = 0;
-               }
-           }
-
-         /* Accounting */
-         nat44_session_update_counters (s0, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b0));
-         /* Per-user LRU list maintenance */
-         nat44_session_update_lru (sm, s0, thread_index);
-
-       trace0:
-         if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
-                            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
-           {
-             nat44_reass_trace_t *t =
-               vlib_add_trace (vm, node, b0, sizeof (*t));
-             t->cached = cached0;
-             t->sw_if_index = sw_if_index0;
-             t->next_index = next0;
-           }
-
-         if (cached0)
-           {
-             n_left_to_next++;
-             to_next--;
-             cached_fragments++;
-           }
-         else
-           {
-             pkts_processed += next0 != SNAT_OUT2IN_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);
-           }
-
-         if (n_left_from == 0 && vec_len (fragments_to_loopback))
-           {
-             from = vlib_frame_vector_args (frame);
-             u32 len = vec_len (fragments_to_loopback);
-             if (len <= VLIB_FRAME_SIZE)
-               {
-                 clib_memcpy_fast (from, fragments_to_loopback,
-                                   sizeof (u32) * len);
-                 n_left_from = len;
-                 vec_reset_length (fragments_to_loopback);
-               }
-             else
-               {
-                 clib_memcpy_fast (from, fragments_to_loopback +
-                                   (len - VLIB_FRAME_SIZE),
-                                   sizeof (u32) * VLIB_FRAME_SIZE);
-                 n_left_from = VLIB_FRAME_SIZE;
-                 _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
-               }
-           }
-       }
-
-      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
-    }
-
-  vlib_node_increment_counter (vm, sm->out2in_reass_node_index,
-                              SNAT_OUT2IN_ERROR_PROCESSED_FRAGMENTS,
-                              pkts_processed);
-  vlib_node_increment_counter (vm, sm->out2in_reass_node_index,
-                              SNAT_OUT2IN_ERROR_CACHED_FRAGMENTS,
-                              cached_fragments);
-
-  nat_send_all_to_node (vm, fragments_to_drop, node,
-                       &node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT],
-                       SNAT_OUT2IN_NEXT_DROP);
-
-  vec_free (fragments_to_drop);
-  vec_free (fragments_to_loopback);
-  return frame->n_vectors;
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_out2in_reass_node) = {
-  .name = "nat44-out2in-reass",
-  .vector_size = sizeof (u32),
-  .format_trace = format_nat44_reass_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-
-  .n_errors = ARRAY_LEN(snat_out2in_error_strings),
-  .error_strings = snat_out2in_error_strings,
-
-  .n_next_nodes = SNAT_OUT2IN_N_NEXT,
-
-  /* edit / add dispositions here */
-  .next_nodes = {
-    [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
-    [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
-    [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
   },
 };
 /* *INDENT-ON* */
@@ -1786,26 +1506,30 @@ VLIB_NODE_FN (snat_out2in_fast_node) (vlib_main_t * vm,
 
          if (PREDICT_FALSE (new_port0 != udp0->dst_port))
            {
+             old_port0 = udp0->dst_port;
+             udp0->dst_port = new_port0;
+
              if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
                {
-                 old_port0 = tcp0->dst_port;
-                 tcp0->dst_port = 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
+             else if (udp0->checksum)
                {
-                 old_port0 = udp0->dst_port;
-                 udp0->dst_port = new_port0;
-                 udp0->checksum = 0;
+                 sum0 = udp0->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 */ );
+                 udp0->checksum = ip_csum_fold (sum0);
                }
            }
          else
@@ -1816,9 +1540,16 @@ VLIB_NODE_FN (snat_out2in_fast_node) (vlib_main_t * vm,
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
                                         dst_address /* changed member */ );
-
                  tcp0->checksum = ip_csum_fold (sum0);
                }
+             else if (udp0->checksum)
+               {
+                 sum0 = udp0->checksum;
+                 sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
+                                        ip4_header_t,
+                                        dst_address /* changed member */ );
+                 udp0->checksum = ip_csum_fold (sum0);
+               }
            }
 
        trace00:
@@ -1868,7 +1599,6 @@ VLIB_REGISTER_NODE (snat_out2in_fast_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
   },
 };
 /* *INDENT-ON* */