NAT: remove worker_by_out lookup hash table (VPP-989)

Change-Id: Ibcd2cf22348ae5a72770a8f8ad25cbe8df7fd390
Signed-off-by: Matus Fabian <matfabia@cisco.com>

3 files changed, 120 insertions, 133 deletions

diff --git a/src/plugins/nat/in2out.c b/src/plugins/nat/in2out.c
index 8b658302c91..dfe103033ae 100755
--- a/src/plugins/nat/in2out.c
+++ b/src/plugins/nat/in2out.c
@@ -241,7 +241,6 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
   u32 address_index = ~0;
   u32 outside_fib_index;
   uword * p;
-  snat_worker_key_t worker_by_out_key;
 
   p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->outside_vrf_id);
   if (! p)
@@ -447,14 +446,6 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
                                1 /* is_add */))
       clib_warning ("out2in key add failed");
 
-  /* Add to translated packets worker lookup */
-  worker_by_out_key.addr = s->out2in.addr;
-  worker_by_out_key.port = s->out2in.port;
-  worker_by_out_key.fib_index = s->out2in.fib_index;
-  kv0.key = worker_by_out_key.as_u64;
-  kv0.value = thread_index;
-  clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv0, 1);
-
   /* log NAT event */
   snat_ipfix_logging_nat44_ses_create(s->in2out.addr.as_u32,
                                       s->out2in.addr.as_u32,
@@ -836,7 +827,6 @@ snat_hairpinning (snat_main_t *sm,
                   u32 proto0)
 {
   snat_session_key_t key0, sm0;
-  snat_worker_key_t k0;
   snat_session_t * s0;
   clib_bihash_kv_8_8_t kv0, value0;
   ip_csum_t sum0;
@@ -849,39 +839,30 @@ snat_hairpinning (snat_main_t *sm,
   key0.fib_index = sm->outside_fib_index;
   kv0.key = key0.as_u64;
 
-  if (sm->num_workers > 1)
+  /* Check if destination is static mappings */
+  if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
     {
-      k0.addr = ip0->dst_address;
-      k0.port = udp0->dst_port;
-      k0.fib_index = sm->outside_fib_index;
-      kv0.key = k0.as_u64;
-      if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
-        return;
-      else
-        ti = value0.value;
+      new_dst_addr0 = sm0.addr.as_u32;
+      new_dst_port0 = sm0.port;
+      vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
     }
+  /* or active session */
   else
-    ti = sm->num_workers;
-
-  /* Check if destination is in active sessions */
-  if (clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0, &value0))
     {
-      /* or static mappings */
-      if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+      if (sm->num_workers > 1)
+        ti = (clib_net_to_host_u16 (udp0->dst_port) - 1024) / sm->port_per_thread;
+      else
+        ti = sm->num_workers;
+
+      if (!clib_bihash_search_8_8 (&sm->per_thread_data[ti].out2in, &kv0, &value0))
         {
-          new_dst_addr0 = sm0.addr.as_u32;
-          new_dst_port0 = sm0.port;
-          vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
-        }
-    }
-  else
-    {
-      si = value0.value;
+          si = value0.value;
 
-      s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
-      new_dst_addr0 = s0->in2out.addr.as_u32;
-      new_dst_port0 = s0->in2out.port;
-      vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+          s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
+          new_dst_addr0 = s0->in2out.addr.as_u32;
+          new_dst_port0 = s0->in2out.port;
+          vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+        }
     }
 
   /* Destination is behind the same NAT, use internal address and port */
@@ -934,7 +915,6 @@ snat_icmp_hairpinning (snat_main_t *sm,
 {
   snat_session_key_t key0, sm0;
   clib_bihash_kv_8_8_t kv0, value0;
-  snat_worker_key_t k0;
   u32 new_dst_addr0 = 0, old_dst_addr0, si, ti = 0;
   ip_csum_t sum0;
   snat_session_t *s0;
@@ -950,16 +930,7 @@ snat_icmp_hairpinning (snat_main_t *sm,
       kv0.key = key0.as_u64;
 
       if (sm->num_workers > 1)
-        {
-          k0.addr = ip0->dst_address;
-          k0.port = icmp_id0;
-          k0.fib_index = sm->outside_fib_index;
-          kv0.key = k0.as_u64;
-          if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
-            return;
-          else
-            ti = value0.value;
-        }
+        ti = (clib_net_to_host_u16 (icmp_id0) - 1024) / sm->port_per_thread;
       else
         ti = sm->num_workers;
 
@@ -1048,7 +1019,6 @@ snat_hairpinning_unknown_proto (snat_main_t *sm,
   clib_bihash_kv_16_8_t s_kv, s_value;
   nat_ed_ses_key_t key;
   snat_session_key_t m_key;
-  snat_worker_key_t w_key;
   snat_static_mapping_t *m;
   ip_csum_t sum;
   snat_session_t *s;
@@ -1080,16 +1050,7 @@ snat_hairpinning_unknown_proto (snat_main_t *sm,
   else
     {
       if (sm->num_workers > 1)
-        {
-          w_key.addr = ip->dst_address;
-          w_key.port = 0;
-          w_key.fib_index = sm->outside_fib_index;
-          kv.key = w_key.as_u64;
-          if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv, &value))
-            return;
-          else
-            ti = value.value;
-        }
+        ti = sm->worker_out2in_cb (ip, sm->outside_fib_index);
       else
         ti = sm->num_workers;
 
diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
index 876b6aad07a..5f3b006efda 100644
--- a/src/plugins/nat/nat.c
+++ b/src/plugins/nat/nat.c
@@ -344,7 +344,7 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports++; \
-                          a->busy_##n##_ports_per_thread[e_port / sm->port_per_thread]++; \
+                          a->busy_##n##_ports_per_thread[(e_port - 1024) / sm->port_per_thread]++; \
                         } \
                       break;
                       foreach_snat_protocol
@@ -394,7 +394,6 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
       if (sm->workers)
         {
           snat_user_key_t w_key0;
-          snat_worker_key_t w_key1;
 
           w_key0.addr = m->local_addr;
           w_key0.fib_index = m->fib_index;
@@ -412,11 +411,7 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
               kv.value = value.value;
             }
 
-          w_key1.addr = m->external_addr;
-          w_key1.port = clib_host_to_net_u16 (m->external_port);
-          w_key1.fib_index = sm->outside_fib_index;
-          kv.key = w_key1.as_u64;
-          clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv, 1);
+          m->worker_index = kv.value;
         }
     }
   else
@@ -440,7 +435,7 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports--; \
-                          a->busy_##n##_ports_per_thread[e_port / sm->port_per_thread]--; \
+                          a->busy_##n##_ports_per_thread[(e_port - 1024) / sm->port_per_thread]--; \
                         } \
                       break;
                       foreach_snat_protocol
@@ -613,7 +608,6 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
   int i;
   nat44_lb_addr_port_t *local;
   snat_user_key_t w_key0;
-  snat_worker_key_t w_key1;
   u32 worker_index = 0;
   snat_main_per_thread_data_t *tsm;
 
@@ -659,7 +653,7 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports++; \
-                          a->busy_##n##_ports_per_thread[e_port / sm->port_per_thread]++; \
+                          a->busy_##n##_ports_per_thread[(e_port - 1024) / sm->port_per_thread]++; \
                         } \
                       break;
                       foreach_snat_protocol
@@ -710,17 +704,8 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
           else
             worker_index = value.value;
 
-          w_key1.addr = m->external_addr;
-          w_key1.port = clib_host_to_net_u16 (m->external_port);
-          w_key1.fib_index = sm->outside_fib_index;
-          kv.key = w_key1.as_u64;
-          kv.value = worker_index;
-          if (clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv, 1))
-            {
-              clib_warning ("worker-by-out add key failed");
-              return VNET_API_ERROR_UNSPECIFIED;
-            }
           tsm = vec_elt_at_index (sm->per_thread_data, worker_index);
+          m->worker_index = worker_index;
         }
       else
         tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
@@ -791,7 +776,7 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
                       if (e_port > 1024) \
                         { \
                           a->busy_##n##_ports--; \
-                          a->busy_##n##_ports_per_thread[e_port / sm->port_per_thread]--; \
+                          a->busy_##n##_ports_per_thread[(e_port - 1024) / sm->port_per_thread]--; \
                         } \
                       break;
                       foreach_snat_protocol
@@ -805,15 +790,7 @@ int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
             }
         }
 
-      w_key1.addr = m->external_addr;
-      w_key1.port = clib_host_to_net_u16 (m->external_port);
-      w_key1.fib_index = sm->outside_fib_index;
-      kv.key = w_key1.as_u64;
-      if (!clib_bihash_search_8_8 (&sm->worker_by_out, &kv, &value))
-        tsm = vec_elt_at_index (sm->per_thread_data, value.value);
-      else
-        tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
-
+      tsm = vec_elt_at_index (sm->per_thread_data, m->worker_index);
       m_key.addr = m->external_addr;
       m_key.port = m->external_port;
       m_key.protocol = m->proto;
@@ -2074,58 +2051,114 @@ static u32
 snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
 {
   snat_main_t *sm = &snat_main;
-  snat_worker_key_t key0;
-  clib_bihash_kv_8_8_t kv0, value0;
-  udp_header_t * udp0;
-  u32 next_worker_index = 0;
-
-  udp0 = ip4_next_header (ip0);
-
-  key0.addr = ip0->dst_address;
-  key0.port = udp0->dst_port;
-  key0.fib_index = rx_fib_index0;
+  udp_header_t *udp;
+  u16 port;
+  snat_session_key_t m_key;
+  clib_bihash_kv_8_8_t kv, value;
+  snat_static_mapping_t *m;
+  nat_ed_ses_key_t key;
+  clib_bihash_kv_16_8_t s_kv, s_value;
+  snat_main_per_thread_data_t *tsm;
+  snat_session_t *s;
+  int i;
+  u32 proto;
 
-  if (PREDICT_FALSE(ip0->protocol == IP_PROTOCOL_ICMP))
+  /* first try static mappings without port */
+  if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
     {
-      icmp46_header_t * icmp0 = (icmp46_header_t *) udp0;
-      icmp_echo_header_t *echo0 = (icmp_echo_header_t *)(icmp0+1);
-      key0.port = echo0->identifier;
+      m_key.addr = ip0->dst_address;
+      m_key.port = 0;
+      m_key.protocol = 0;
+      m_key.fib_index = rx_fib_index0;
+      kv.key = m_key.as_u64;
+      if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+        {
+          m = pool_elt_at_index (sm->static_mappings, value.value);
+          return m->worker_index;
+        }
     }
 
-  kv0.key = key0.as_u64;
+  proto = ip_proto_to_snat_proto (ip0->protocol);
+  udp = ip4_next_header (ip0);
+  port = udp->dst_port;
 
-  /* Ever heard of of the "user" before? */
-  if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+  /* unknown protocol */
+  if (PREDICT_FALSE (proto == ~0))
     {
-      key0.port = 0;
-      kv0.key = key0.as_u64;
+      key.l_addr = ip0->dst_address;
+      key.r_addr = ip0->src_address;
+      key.fib_index = rx_fib_index0;
+      key.proto = ip0->protocol;
+      key.rsvd = 0;
+      key.l_port = 0;
+      s_kv.key[0] = key.as_u64[0];
+      s_kv.key[1] = key.as_u64[1];
 
-      if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+      if (!clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value))
         {
-          /* No, assign next available worker (RR) */
-          next_worker_index = sm->first_worker_index;
-          if (vec_len (sm->workers))
+          for (i = 0; i < _vec_len (sm->per_thread_data); i++)
             {
-              next_worker_index +=
-                sm->workers[sm->next_worker++ % _vec_len (sm->workers)];
+              tsm = vec_elt_at_index (sm->per_thread_data, i);
+              if (!pool_is_free_index(tsm->sessions, s_value.value))
+                {
+                  s = pool_elt_at_index (tsm->sessions, s_value.value);
+                  if (s->out2in.addr.as_u32 == ip0->dst_address.as_u32 &&
+                      s->out2in.port == ip0->protocol &&
+                      snat_is_unk_proto_session (s))
+                    return i;
+                }
             }
-        }
+         }
+
+      /* if no session use current thread */
+      return vlib_get_thread_index ();
+    }
+
+  if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_ICMP))
+    {
+      icmp46_header_t * icmp = (icmp46_header_t *) udp;
+      icmp_echo_header_t *echo = (icmp_echo_header_t *)(icmp + 1);
+      if (!icmp_is_error_message (icmp))
+        port = echo->identifier;
       else
         {
-          /* Static mapping without port */
-          next_worker_index = value0.value;
+          ip4_header_t *inner_ip = (ip4_header_t *)(echo + 1);
+          proto = ip_proto_to_snat_proto (inner_ip->protocol);
+          void *l4_header = ip4_next_header (inner_ip);
+          switch (proto)
+            {
+            case SNAT_PROTOCOL_ICMP:
+              icmp = (icmp46_header_t*)l4_header;
+              echo = (icmp_echo_header_t *)(icmp + 1);
+              port = echo->identifier;
+              break;
+            case SNAT_PROTOCOL_UDP:
+            case SNAT_PROTOCOL_TCP:
+              port = ((tcp_udp_header_t*)l4_header)->src_port;
+              break;
+            default:
+              return vlib_get_thread_index ();
+            }
         }
+    }
 
-      /* Add to translated packets worker lookup */
-      key0.port = udp0->dst_port;
-      kv0.key = key0.as_u64;
-      kv0.value = next_worker_index;
-      clib_bihash_add_del_8_8 (&sm->worker_by_out, &kv0, 1);
+  /* try static mappings with port */
+  if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
+    {
+      m_key.addr = ip0->dst_address;
+      m_key.port = clib_net_to_host_u16 (port);
+      m_key.protocol = proto;
+      m_key.fib_index = rx_fib_index0;
+      kv.key = m_key.as_u64;
+      if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+        {
+          m = pool_elt_at_index (sm->static_mappings, value.value);
+          return m->worker_index;
+        }
     }
-  else
-    next_worker_index = value0.value;
 
-  return next_worker_index;
+  /* worker by outside port */
+  return (u32) ((clib_net_to_host_u16 (port) - 1024) / sm->port_per_thread);
 }
 
 static clib_error_t *
@@ -2233,9 +2266,6 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
           clib_bihash_init_8_8 (&sm->worker_by_in, "worker-by-in", user_buckets,
                                 user_memory_size);
 
-          clib_bihash_init_8_8 (&sm->worker_by_out, "worker-by-out",
-                                translation_buckets, translation_memory_size);
-
           clib_bihash_init_16_8 (&sm->in2out_ed, "in2out-ed",
                                  translation_buckets, translation_memory_size);
 
@@ -2618,8 +2648,6 @@ show_snat_command_fn (vlib_main_t * vm,
                                verbose - 1);
               vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->worker_by_in,
                                verbose - 1);
-              vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->worker_by_out,
-                               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 f970821b1c9..20e45952d55 100644
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -224,6 +224,7 @@ typedef struct {
   u32 vrf_id;
   u32 fib_index;
   snat_protocol_t proto;
+  u32 worker_index;
   nat44_lb_addr_port_t *locals;
 } snat_static_mapping_t;
 
@@ -285,9 +286,6 @@ typedef struct snat_main_s {
   /* Non-translated packets worker lookup => src address + VRF */
   clib_bihash_8_8_t worker_by_in;
 
-  /* Translated packets worker lookup => IP address + port number */
-  clib_bihash_8_8_t worker_by_out;
-
   snat_icmp_match_function_t * icmp_match_in2out_cb;
   snat_icmp_match_function_t * icmp_match_out2in_cb;