nat: respect udp checksum
[vpp.git] / src / plugins / nat / in2out.c
index 15dae65..802202d 100755 (executable)
@@ -29,6 +29,7 @@
 #include <nat/nat_reass.h>
 #include <nat/nat_inlines.h>
 #include <nat/nat_syslog.h>
+#include <nat/nat_ha.h>
 
 #include <vppinfra/hash.h>
 #include <vppinfra/error.h>
@@ -72,13 +73,6 @@ format_snat_in2out_fast_trace (u8 * s, va_list * args)
   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_output_node;
-vlib_node_registration_t snat_in2out_output_slowpath_node;
-vlib_node_registration_t nat44_in2out_reass_node;
-
 #define foreach_snat_in2out_error                       \
 _(UNSUPPORTED_PROTOCOL, "unsupported protocol")         \
 _(IN2OUT_PACKETS, "good in2out packets processed")      \
@@ -198,6 +192,7 @@ nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
   return 0;
 }
 
+#ifndef CLIB_MARCH_VARIANT
 int
 nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
 {
@@ -215,9 +210,10 @@ nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
     {
       s_kv.key = s->out2in.as_u64;
       if (clib_bihash_add_del_8_8 (&tsm->out2in, &s_kv, 0))
-       nat_log_warn ("out2in key del failed");
+       nat_elog_warn ("out2in key del failed");
 
-      snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
+      snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
+                                          s->in2out.addr.as_u32,
                                           s->out2in.addr.as_u32,
                                           s->in2out.protocol,
                                           s->in2out.port,
@@ -229,6 +225,10 @@ nat44_i2o_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);
@@ -239,6 +239,7 @@ nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
 
   return 0;
 }
+#endif
 
 static u32
 slow_path (snat_main_t * sm, vlib_buffer_t * b0,
@@ -269,8 +270,8 @@ slow_path (snat_main_t * sm, vlib_buffer_t * b0,
   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
     {
       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_ipfix_logging_max_sessions (sm->max_translations);
-      nat_log_notice ("maximum sessions exceeded");
+      nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
+      nat_elog_notice ("maximum sessions exceeded");
       return SNAT_IN2OUT_NEXT_DROP;
     }
 
@@ -306,15 +307,15 @@ slow_path (snat_main_t * sm, vlib_buffer_t * b0,
                              thread_index);
   if (!u)
     {
-      nat_log_warn ("create NAT user failed");
+      nat_elog_warn ("create NAT user failed");
       return SNAT_IN2OUT_NEXT_DROP;
     }
 
-  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 SNAT_IN2OUT_NEXT_DROP;
     }
 
@@ -362,7 +363,7 @@ slow_path (snat_main_t * sm, vlib_buffer_t * b0,
   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;
   kv0.value = s - sm->per_thread_data[thread_index].sessions;
@@ -370,10 +371,11 @@ slow_path (snat_main_t * sm, vlib_buffer_t * b0,
   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 (s->in2out.addr.as_u32,
+  snat_ipfix_logging_nat44_ses_create (thread_index,
+                                      s->in2out.addr.as_u32,
                                       s->out2in.addr.as_u32,
                                       s->in2out.protocol,
                                       s->in2out.port,
@@ -383,9 +385,16 @@ slow_path (snat_main_t * sm, vlib_buffer_t * b0,
                           &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 next0;
 }
 
+#ifndef CLIB_MARCH_VARIANT
 static_always_inline
   snat_in2out_error_t icmp_get_key (ip4_header_t * ip0,
                                    snat_session_key_t * p_key0)
@@ -548,7 +557,9 @@ out:
     *(snat_session_t **) d = s0;
   return next0;
 }
+#endif
 
+#ifndef CLIB_MARCH_VARIANT
 /**
  * Get address and port values to be used for ICMP packet translation
  *
@@ -630,7 +641,9 @@ out2:
   *p_dont_translate = dont_translate;
   return next0;
 }
+#endif
 
+#ifndef CLIB_MARCH_VARIANT
 u32
 icmp_in2out (snat_main_t * sm,
             vlib_buffer_t * b0,
@@ -780,6 +793,7 @@ icmp_in2out (snat_main_t * sm,
 out:
   return next0;
 }
+#endif
 
 static inline u32
 icmp_in2out_slow_path (snat_main_t * sm,
@@ -800,7 +814,7 @@ icmp_in2out_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);
     }
@@ -861,8 +875,8 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
   u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
     0, fragments = 0;
 
-  stats_node_index = is_slow_path ? snat_in2out_slowpath_node.index :
-    snat_in2out_node.index;
+  stats_node_index = is_slow_path ? sm->in2out_slowpath_node_index :
+    sm->in2out_node_index;
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -1061,12 +1075,11 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                                 src_address /* changed member */ );
          ip0->checksum = ip_csum_fold (sum0);
 
+         old_port0 = udp0->src_port;
+         new_port0 = udp0->src_port = s0->out2in.port;
+
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
-             old_port0 = tcp0->src_port;
-             tcp0->src_port = s0->out2in.port;
-             new_port0 = tcp0->src_port;
-
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                     ip4_header_t,
@@ -1080,16 +1093,24 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
            }
          else
            {
-             old_port0 = udp0->src_port;
-             udp0->src_port = s0->out2in.port;
-             udp0->checksum = 0;
+             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:
@@ -1250,12 +1271,11 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                                 src_address /* changed member */ );
          ip1->checksum = ip_csum_fold (sum1);
 
+         old_port1 = udp1->src_port;
+         new_port1 = udp1->src_port = s1->out2in.port;
+
          if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
            {
-             old_port1 = tcp1->src_port;
-             tcp1->src_port = s1->out2in.port;
-             new_port1 = tcp1->src_port;
-
              sum1 = tcp1->checksum;
              sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
                                     ip4_header_t,
@@ -1269,16 +1289,24 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
            }
          else
            {
-             old_port1 = udp1->src_port;
-             udp1->src_port = s1->out2in.port;
-             udp1->checksum = 0;
+             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);
        trace01:
@@ -1474,12 +1502,11 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                                 src_address /* changed member */ );
          ip0->checksum = ip_csum_fold (sum0);
 
+         old_port0 = udp0->src_port;
+         new_port0 = udp0->src_port = s0->out2in.port;
+
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
-             old_port0 = tcp0->src_port;
-             tcp0->src_port = s0->out2in.port;
-             new_port0 = tcp0->src_port;
-
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                     ip4_header_t,
@@ -1493,16 +1520,24 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
            }
          else
            {
-             old_port0 = udp0->src_port;
-             udp0->src_port = s0->out2in.port;
-             udp0->checksum = 0;
+             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);
 
@@ -1550,9 +1585,9 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
   return frame->n_vectors;
 }
 
-static uword
-snat_in2out_fast_path_fn (vlib_main_t * vm,
-                         vlib_node_runtime_t * node, vlib_frame_t * frame)
+VLIB_NODE_FN (snat_in2out_node) (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 */ ,
                                     0);
@@ -1560,7 +1595,6 @@ snat_in2out_fast_path_fn (vlib_main_t * vm,
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (snat_in2out_node) = {
-  .function = snat_in2out_fast_path_fn,
   .name = "nat44-in2out",
   .vector_size = sizeof (u32),
   .format_trace = format_snat_in2out_trace,
@@ -1584,12 +1618,9 @@ VLIB_REGISTER_NODE (snat_in2out_node) = {
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_node, snat_in2out_fast_path_fn);
-
-static uword
-snat_in2out_output_fast_path_fn (vlib_main_t * vm,
-                                vlib_node_runtime_t * node,
-                                vlib_frame_t * frame)
+VLIB_NODE_FN (snat_in2out_output_node) (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 */ ,
                                     1);
@@ -1597,7 +1628,6 @@ snat_in2out_output_fast_path_fn (vlib_main_t * vm,
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (snat_in2out_output_node) = {
-  .function = snat_in2out_output_fast_path_fn,
   .name = "nat44-in2out-output",
   .vector_size = sizeof (u32),
   .format_trace = format_snat_in2out_trace,
@@ -1621,12 +1651,9 @@ VLIB_REGISTER_NODE (snat_in2out_output_node) = {
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_node,
-                             snat_in2out_output_fast_path_fn);
-
-static uword
-snat_in2out_slow_path_fn (vlib_main_t * vm,
-                         vlib_node_runtime_t * node, vlib_frame_t * frame)
+VLIB_NODE_FN (snat_in2out_slowpath_node) (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 */ ,
                                     0);
@@ -1634,7 +1661,6 @@ snat_in2out_slow_path_fn (vlib_main_t * vm,
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
-  .function = snat_in2out_slow_path_fn,
   .name = "nat44-in2out-slowpath",
   .vector_size = sizeof (u32),
   .format_trace = format_snat_in2out_trace,
@@ -1658,13 +1684,9 @@ VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_slowpath_node,
-                             snat_in2out_slow_path_fn);
-
-static uword
-snat_in2out_output_slow_path_fn (vlib_main_t * vm,
-                                vlib_node_runtime_t * node,
-                                vlib_frame_t * frame)
+VLIB_NODE_FN (snat_in2out_output_slowpath_node) (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 */ ,
                                     1);
@@ -1672,7 +1694,6 @@ snat_in2out_output_slow_path_fn (vlib_main_t * vm,
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
-  .function = snat_in2out_output_slow_path_fn,
   .name = "nat44-in2out-output-slowpath",
   .vector_size = sizeof (u32),
   .format_trace = format_snat_in2out_trace,
@@ -1696,12 +1717,9 @@ VLIB_REGISTER_NODE (snat_in2out_output_slowpath_node) = {
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_output_slowpath_node,
-                             snat_in2out_output_slow_path_fn);
-
-static uword
-nat44_in2out_reass_node_fn (vlib_main_t * vm,
-                           vlib_node_runtime_t * node, vlib_frame_t * frame)
+VLIB_NODE_FN (nat44_in2out_reass_node) (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;
@@ -1780,7 +1798,7 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
            {
              next0 = SNAT_IN2OUT_NEXT_DROP;
              b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_REASS];
-             nat_log_notice ("maximum reassemblies exceeded");
+             nat_elog_notice ("maximum reassemblies exceeded");
              goto trace0;
            }
 
@@ -1844,10 +1862,10 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
              if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
                {
                  if (nat_ip4_reass_add_fragment
-                     (reass0, bi0, &fragments_to_drop))
+                     (thread_index, reass0, bi0, &fragments_to_drop))
                    {
                      b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_FRAG];
-                     nat_log_notice
+                     nat_elog_notice
                        ("maximum fragments per reassembly exceeded");
                      next0 = SNAT_IN2OUT_NEXT_DROP;
                      goto trace0;
@@ -1872,12 +1890,11 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
 
          if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
            {
+             old_port0 = udp0->src_port;
+             new_port0 = udp0->src_port = s0->out2in.port;
+
              if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
                {
-                 old_port0 = tcp0->src_port;
-                 tcp0->src_port = s0->out2in.port;
-                 new_port0 = tcp0->src_port;
-
                  sum0 = tcp0->checksum;
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
@@ -1887,11 +1904,16 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
                                         length /* changed member */ );
                  tcp0->checksum = ip_csum_fold (sum0);
                }
-             else
+             else if (PREDICT_FALSE (udp0->checksum))
                {
-                 old_port0 = udp0->src_port;
-                 udp0->src_port = s0->out2in.port;
-                 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);
                }
            }
 
@@ -1901,8 +1923,8 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
 
          /* 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);
 
@@ -1958,10 +1980,10 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
 
-  vlib_node_increment_counter (vm, nat44_in2out_reass_node.index,
+  vlib_node_increment_counter (vm, sm->in2out_reass_node_index,
                               SNAT_IN2OUT_ERROR_PROCESSED_FRAGMENTS,
                               pkts_processed);
-  vlib_node_increment_counter (vm, nat44_in2out_reass_node.index,
+  vlib_node_increment_counter (vm, sm->in2out_reass_node_index,
                               SNAT_IN2OUT_ERROR_CACHED_FRAGMENTS,
                               cached_fragments);
 
@@ -1976,7 +1998,6 @@ nat44_in2out_reass_node_fn (vlib_main_t * vm,
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (nat44_in2out_reass_node) = {
-  .function = nat44_in2out_reass_node_fn,
   .name = "nat44-in2out-reass",
   .vector_size = sizeof (u32),
   .format_trace = format_nat44_reass_trace,
@@ -1996,13 +2017,9 @@ VLIB_REGISTER_NODE (nat44_in2out_reass_node) = {
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_in2out_reass_node,
-                             nat44_in2out_reass_node_fn);
-
-static uword
-snat_in2out_fast_static_map_fn (vlib_main_t * vm,
-                               vlib_node_runtime_t * node,
-                               vlib_frame_t * frame)
+VLIB_NODE_FN (snat_in2out_fast_node) (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;
@@ -2010,7 +2027,7 @@ snat_in2out_fast_static_map_fn (vlib_main_t * vm,
   snat_main_t *sm = &snat_main;
   u32 stats_node_index;
 
-  stats_node_index = snat_in2out_fast_node.index;
+  stats_node_index = sm->in2out_fast_node_index;
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -2107,11 +2124,11 @@ snat_in2out_fast_static_map_fn (vlib_main_t * vm,
 
          if (PREDICT_FALSE (new_port0 != udp0->dst_port))
            {
+             old_port0 = udp0->src_port;
+             udp0->src_port = new_port0;
+
              if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
                {
-                 old_port0 = tcp0->src_port;
-                 tcp0->src_port = new_port0;
-
                  sum0 = tcp0->checksum;
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
@@ -2122,11 +2139,16 @@ snat_in2out_fast_static_map_fn (vlib_main_t * vm,
                  mss_clamping (sm, tcp0, &sum0);
                  tcp0->checksum = ip_csum_fold (sum0);
                }
-             else
+             else if (udp0->checksum)
                {
-                 old_port0 = udp0->src_port;
-                 udp0->src_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
@@ -2140,6 +2162,14 @@ snat_in2out_fast_static_map_fn (vlib_main_t * vm,
                  mss_clamping (sm, tcp0, &sum0);
                  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);
+               }
            }
 
          /* Hairpinning */
@@ -2175,7 +2205,6 @@ snat_in2out_fast_static_map_fn (vlib_main_t * vm,
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
-  .function = snat_in2out_fast_static_map_fn,
   .name = "nat44-in2out-fast",
   .vector_size = sizeof (u32),
   .format_trace = format_snat_in2out_fast_trace,
@@ -2199,9 +2228,6 @@ VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (snat_in2out_fast_node,
-                             snat_in2out_fast_static_map_fn);
-
 /*
  * fd.io coding-style-patch-verification: ON
  *