4 files changed, 30 insertions, 97 deletions

diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
index 944162556d3..c2f9586ce7d 100644
--- a/src/plugins/nat/nat.c
+++ b/src/plugins/nat/nat.c
@@ -390,28 +390,12 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
       kv.value = m - sm->static_mappings;
       clib_bihash_add_del_8_8(&sm->static_mapping_by_external, &kv, 1);
 
-      /* Assign worker */
       if (sm->workers)
         {
-          snat_user_key_t w_key0;
-
-          w_key0.addr = m->local_addr;
-          w_key0.fib_index = m->fib_index;
-          kv.key = w_key0.as_u64;
-
-          if (clib_bihash_search_8_8 (&sm->worker_by_in, &kv, &value))
-            {
-              kv.value = sm->first_worker_index +
-                sm->workers[sm->next_worker++ % vec_len (sm->workers)];
-
-              clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv, 1);
-            }
-          else
-            {
-              kv.value = value.value;
-            }
-
-          m->worker_index = kv.value;
+          ip4_header_t ip = {
+            .src_address = m->local_addr,
+          };
+          m->worker_index = sm->worker_in2out_cb (&ip, m->fib_index);
         }
     }
   else
@@ -478,8 +462,8 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
           u_key.addr = m->local_addr;
           u_key.fib_index = m->fib_index;
           kv.key = u_key.as_u64;
-          if (!clib_bihash_search_8_8 (&sm->worker_by_in, &kv, &value))
-            tsm = vec_elt_at_index (sm->per_thread_data, value.value);
+          if (sm->num_workers)
+            tsm = vec_elt_at_index (sm->per_thread_data, m->worker_index);
           else
             tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
           if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
@@ -607,7 +591,6 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
   snat_address_t *a = 0;
   int i;
   nat44_lb_addr_port_t *local;
-  snat_user_key_t w_key0;
   u32 worker_index = 0;
   snat_main_per_thread_data_t *tsm;
 
@@ -694,16 +677,8 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
       /* Assign worker */
       if (sm->workers)
         {
-          w_key0.addr = locals[0].addr;
-          w_key0.fib_index = fib_index;
-          kv.key = w_key0.as_u64;
-
-          if (clib_bihash_search_8_8 (&sm->worker_by_in, &kv, &value))
-            worker_index = sm->first_worker_index +
-              sm->workers[sm->next_worker++ % vec_len (sm->workers)];
-          else
-            worker_index = value.value;
-
+          worker_index = sm->first_worker_index +
+            sm->workers[sm->next_worker++ % vec_len (sm->workers)];
           tsm = vec_elt_at_index (sm->per_thread_data, worker_index);
           m->worker_index = worker_index;
         }
@@ -730,6 +705,7 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
           locals[i].prefix = (i == 0) ? locals[i].probability :\
             (locals[i - 1].prefix + locals[i].probability);
           vec_add1 (m->locals, locals[i]);
+
           m_key.port = clib_host_to_net_u16 (locals[i].port);
           kv.key = m_key.as_u64;
           kv.value = ~0ULL;
@@ -738,19 +714,6 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
               clib_warning ("in2out key add failed");
               return VNET_API_ERROR_UNSPECIFIED;
             }
-          /* Assign worker */
-          if (sm->workers)
-            {
-              w_key0.addr = locals[i].addr;
-              w_key0.fib_index = fib_index;
-              kv.key = w_key0.as_u64;
-              kv.value = worker_index;
-              if (clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv, 1))
-                {
-                  clib_warning ("worker-by-in key add failed");
-                  return VNET_API_ERROR_UNSPECIFIED;
-                }
-            }
         }
     }
   else
@@ -801,6 +764,7 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
           clib_warning ("static_mapping_by_external key del failed");
           return VNET_API_ERROR_UNSPECIFIED;
         }
+
       m_key.port = clib_host_to_net_u16 (m->external_port);
       kv.key = m_key.as_u64;
       if (clib_bihash_add_del_8_8(&tsm->out2in, &kv, 0))
@@ -820,6 +784,7 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
               clib_warning ("static_mapping_by_local key del failed");
               return VNET_API_ERROR_UNSPECIFIED;
             }
+
           m_key.port = clib_host_to_net_u16 (local->port);
           kv.key = m_key.as_u64;
           if (clib_bihash_add_del_8_8(&tsm->in2out, &kv, 0))
@@ -2017,32 +1982,17 @@ static u32
 snat_get_worker_in2out_cb (ip4_header_t * ip0, u32 rx_fib_index0)
 {
   snat_main_t *sm = &snat_main;
-  snat_user_key_t key0;
-  clib_bihash_kv_8_8_t kv0, value0;
   u32 next_worker_index = 0;
+  u32 hash;
 
-  key0.addr = ip0->src_address;
-  key0.fib_index = rx_fib_index0;
-
-  kv0.key = key0.as_u64;
+  next_worker_index = sm->first_worker_index;
+  hash = ip0->src_address.as_u32 + (ip0->src_address.as_u32 >> 8) +
+         (ip0->src_address.as_u32 >> 16) + (ip0->src_address.as_u32 >>24);
 
-  /* Ever heard of of the "user" before? */
-  if (clib_bihash_search_8_8 (&sm->worker_by_in, &kv0, &value0))
-    {
-      /* No, assign next available worker (RR) */
-      next_worker_index = sm->first_worker_index;
-      if (vec_len (sm->workers))
-        {
-          next_worker_index +=
-            sm->workers[sm->next_worker++ % _vec_len (sm->workers)];
-        }
-
-      /* add non-traslated packets worker lookup */
-      kv0.value = next_worker_index;
-      clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv0, 1);
-    }
+  if (PREDICT_TRUE (is_pow2 (_vec_len (sm->workers))))
+    next_worker_index += sm->workers[hash & (_vec_len (sm->workers) - 1)];
   else
-    next_worker_index = value0.value;
+    next_worker_index += sm->workers[hash % _vec_len (sm->workers)];
 
   return next_worker_index;
 }
@@ -2265,9 +2215,6 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
                                     user_memory_size);
             }
 
-          clib_bihash_init_8_8 (&sm->worker_by_in, "worker-by-in", user_buckets,
-                                user_memory_size);
-
           clib_bihash_init_16_8 (&sm->in2out_ed, "in2out-ed",
                                  translation_buckets, translation_memory_size);
 
@@ -2648,8 +2595,6 @@ show_snat_command_fn (vlib_main_t * vm,
                                verbose - 1);
               vlib_cli_output (vm, "%U", format_bihash_16_8, &sm->out2in_ed,
                                verbose - 1);
-              vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->worker_by_in,
-                               verbose - 1);
               vec_foreach_index (j, sm->per_thread_data)
                 {
                   tsm = vec_elt_at_index (sm->per_thread_data, j);
diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
index d34ff07b7fe..e467fde75f3 100644
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -95,19 +95,6 @@ typedef struct {
   };
 } snat_user_key_t;
 
-typedef struct {
-  union
-  {
-    struct
-    {
-      ip4_address_t addr;
-      u16 port;
-      u16 fib_index;
-    };
-    u64 as_u64;
-  };
-} snat_worker_key_t;
-
 
 #define foreach_snat_protocol \
   _(UDP, 0, udp, "udp")       \
@@ -283,9 +270,6 @@ typedef struct snat_main_s {
   clib_bihash_16_8_t out2in_ed;
   clib_bihash_16_8_t in2out_ed;
 
-  /* Non-translated packets worker lookup => src address + VRF */
-  clib_bihash_8_8_t worker_by_in;
-
   snat_icmp_match_function_t * icmp_match_in2out_cb;
   snat_icmp_match_function_t * icmp_match_out2in_cb;
 
diff --git a/src/plugins/nat/nat_api.c b/src/plugins/nat/nat_api.c
index 50b4a9ae8e1..b56b4436adc 100644
--- a/src/plugins/nat/nat_api.c
+++ b/src/plugins/nat/nat_api.c
@@ -856,6 +856,7 @@ static void
   snat_user_t *u;
   u32 session_index, head_index, elt_index;
   dlist_elt_t *head, *elt;
+  ip4_header_t ip;
 
   q = vl_api_client_index_to_input_queue (mp->client_index);
   if (q == 0)
@@ -864,10 +865,13 @@ static void
     return;
 
   clib_memcpy (&ukey.addr, mp->ip_address, 4);
+  ip.src_address.as_u32 = ukey.addr.as_u32;
   ukey.fib_index = fib_table_find (FIB_PROTOCOL_IP4, ntohl (mp->vrf_id));
   key.key = ukey.as_u64;
-  if (!clib_bihash_search_8_8 (&sm->worker_by_in, &key, &value))
-    tsm = vec_elt_at_index (sm->per_thread_data, value.value);
+  if (sm->num_workers)
+    tsm =
+      vec_elt_at_index (sm->per_thread_data,
+			sm->worker_in2out_cb (&ip, ukey.fib_index));
   else
     tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
   if (clib_bihash_search_8_8 (&tsm->user_hash, &key, &value))
@@ -2093,16 +2097,20 @@ vl_api_nat44_user_session_dump_t_handler (vl_api_nat44_user_session_dump_t *
   snat_user_t *u;
   u32 session_index, head_index, elt_index;
   dlist_elt_t *head, *elt;
+  ip4_header_t ip;
 
   q = vl_api_client_index_to_input_queue (mp->client_index);
   if (q == 0)
     return;
 
   clib_memcpy (&ukey.addr, mp->ip_address, 4);
+  ip.src_address.as_u32 = ukey.addr.as_u32;
   ukey.fib_index = fib_table_find (FIB_PROTOCOL_IP4, ntohl (mp->vrf_id));
   key.key = ukey.as_u64;
-  if (!clib_bihash_search_8_8 (&sm->worker_by_in, &key, &value))
-    tsm = vec_elt_at_index (sm->per_thread_data, value.value);
+  if (sm->num_workers)
+    tsm =
+      vec_elt_at_index (sm->per_thread_data,
+			sm->worker_in2out_cb (&ip, ukey.fib_index));
   else
     tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
   if (clib_bihash_search_8_8 (&tsm->user_hash, &key, &value))
diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
index e5426c1a80e..802c3312a84 100755
--- a/src/plugins/nat/out2in.c
+++ b/src/plugins/nat/out2in.c
@@ -176,10 +176,6 @@ create_session_for_static_mapping (snat_main_t *sm,
       /* add user */
       clib_bihash_add_del_8_8 (&sm->per_thread_data[thread_index].user_hash,
                                &kv0, 1 /* is_add */);
-
-      /* add non-traslated packets worker lookup */
-      kv0.value = thread_index;
-      clib_bihash_add_del_8_8 (&sm->worker_by_in, &kv0, 1);
     }
   else
     {