SNAT: in2out translation as an output feature hairpinning (VPP-913)
[vpp.git] / src / plugins / snat / out2in.c
index 3d7b106..329d67d 100644 (file)
@@ -137,6 +137,9 @@ create_session_for_static_mapping (snat_main_t *sm,
   clib_bihash_kv_8_8_t kv0, value0;
   dlist_elt_t * per_user_translation_list_elt;
   dlist_elt_t * per_user_list_head_elt;
+  ip4_header_t *ip0;
+
+  ip0 = vlib_buffer_get_current (b0);
 
   user_key.addr = in2out.addr;
   user_key.fib_index = in2out.fib_index;
@@ -180,6 +183,7 @@ create_session_for_static_mapping (snat_main_t *sm,
 
   s->outside_address_index = ~0;
   s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+  s->ext_host_addr.as_u32 = ip0->dst_address.as_u32;
   u->nstaticsessions++;
 
   /* Create list elts */
@@ -308,6 +312,8 @@ u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
   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);
   if (err != -1)
     {
@@ -609,6 +615,140 @@ static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
   return next0;
 }
 
+static void
+snat_out2in_unknown_proto (snat_main_t *sm,
+                           vlib_buffer_t * b,
+                           ip4_header_t * ip,
+                           u32 rx_fib_index,
+                           u32 thread_index,
+                           f64 now,
+                           vlib_main_t * vm)
+{
+  clib_bihash_kv_8_8_t kv, value;
+  clib_bihash_kv_16_8_t s_kv, s_value;
+  snat_static_mapping_t *m;
+  snat_session_key_t m_key;
+  u32 old_addr, new_addr;
+  ip_csum_t sum;
+  snat_unk_proto_ses_key_t key;
+  snat_session_t * s;
+  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
+  snat_user_key_t u_key;
+  snat_user_t *u;
+  dlist_elt_t *head, *elt;
+
+  old_addr = ip->dst_address.as_u32;
+
+  key.l_addr = ip->dst_address;
+  key.r_addr = ip->src_address;
+  key.fib_index = rx_fib_index;
+  key.proto = ip->protocol;
+  key.rsvd[0] = key.rsvd[1] = key.rsvd[2] = 0;
+  s_kv.key[0] = key.as_u64[0];
+  s_kv.key[1] = key.as_u64[1];
+
+  if (!clib_bihash_search_16_8 (&sm->out2in_unk_proto, &s_kv, &s_value))
+    {
+      s = pool_elt_at_index (tsm->sessions, s_value.value);
+      new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
+    }
+  else
+    {
+      m_key.addr = ip->dst_address;
+      m_key.port = 0;
+      m_key.protocol = 0;
+      m_key.fib_index = rx_fib_index;
+      kv.key = m_key.as_u64;
+      if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
+        return;
+
+      m = pool_elt_at_index (sm->static_mappings, value.value);
+
+      new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
+
+      u_key.addr = ip->src_address;
+      u_key.fib_index = m->fib_index;
+      kv.key = u_key.as_u64;
+
+      /* Ever heard of the "user" = src ip4 address before? */
+      if (clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
+        {
+          /* no, make a new one */
+          pool_get (tsm->users, u);
+          memset (u, 0, sizeof (*u));
+          u->addr = ip->src_address;
+          u->fib_index = rx_fib_index;
+
+          pool_get (tsm->list_pool, head);
+          u->sessions_per_user_list_head_index = head - tsm->list_pool;
+
+          clib_dlist_init (tsm->list_pool,
+                           u->sessions_per_user_list_head_index);
+
+          kv.value = u - tsm->users;
+
+          /* add user */
+          clib_bihash_add_del_8_8 (&sm->user_hash, &kv, 1);
+        }
+      else
+        {
+          u = pool_elt_at_index (tsm->users, value.value);
+        }
+
+      /* Create a new session */
+      pool_get (tsm->sessions, s);
+      memset (s, 0, sizeof (*s));
+
+      s->ext_host_addr.as_u32 = ip->src_address.as_u32;
+      s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
+      s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
+      s->outside_address_index = ~0;
+      s->out2in.addr.as_u32 = old_addr;
+      s->out2in.fib_index = rx_fib_index;
+      s->in2out.addr.as_u32 = new_addr;
+      s->in2out.fib_index = m->fib_index;
+      s->in2out.port = s->out2in.port = ip->protocol;
+      u->nstaticsessions++;
+
+      /* Create list elts */
+      pool_get (tsm->list_pool, elt);
+      clib_dlist_init (tsm->list_pool, elt - tsm->list_pool);
+      elt->value = s - tsm->sessions;
+      s->per_user_index = elt - tsm->list_pool;
+      s->per_user_list_head_index = u->sessions_per_user_list_head_index;
+      clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+                          s->per_user_index);
+
+      /* Add to lookup tables */
+      s_kv.value = s - tsm->sessions;
+      if (clib_bihash_add_del_16_8 (&sm->out2in_unk_proto, &s_kv, 1))
+        clib_warning ("out2in key add failed");
+
+      key.l_addr = ip->dst_address;
+      key.fib_index = m->fib_index;
+      s_kv.key[0] = key.as_u64[0];
+      s_kv.key[1] = key.as_u64[1];
+      if (clib_bihash_add_del_16_8 (&sm->in2out_unk_proto, &s_kv, 1))
+        clib_warning ("in2out key add failed");
+   }
+
+  /* Update IP checksum */
+  sum = ip->checksum;
+  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
+  ip->checksum = ip_csum_fold (sum);
+
+  vnet_buffer(b)->sw_if_index[VLIB_TX] = s->in2out.fib_index;
+
+  /* Accounting */
+  s->last_heard = now;
+  s->total_pkts++;
+  s->total_bytes += vlib_buffer_length_in_chain (vm, b);
+  /* Per-user LRU list maintenance */
+  clib_dlist_remove (tsm->list_pool, s->per_user_index);
+  clib_dlist_addtail (tsm->list_pool, s->per_user_list_head_index,
+                      s->per_user_index);
+}
+
 static uword
 snat_out2in_node_fn (vlib_main_t * vm,
                  vlib_node_runtime_t * node,
@@ -678,7 +818,10 @@ snat_out2in_node_fn (vlib_main_t * vm,
 
          b0 = vlib_get_buffer (vm, bi0);
          b1 = vlib_get_buffer (vm, bi1);
-            
+
+          vnet_buffer (b0)->snat.flags = 0;
+          vnet_buffer (b1)->snat.flags = 0;
+
           ip0 = vlib_buffer_get_current (b0);
           udp0 = ip4_next_header (ip0);
           tcp0 = (tcp_header_t *) udp0;
@@ -701,7 +844,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 
           if (PREDICT_FALSE (proto0 == ~0))
+            {
+              snat_out2in_unknown_proto(sm, b0, ip0, rx_fib_index0,
+                                        thread_index, now, vm);
               goto trace0;
+            }
 
           if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
             {
@@ -836,7 +983,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
           proto1 = ip_proto_to_snat_proto (ip1->protocol);
 
           if (PREDICT_FALSE (proto1 == ~0))
+            {
+              snat_out2in_unknown_proto(sm, b1, ip1, rx_fib_index1,
+                                        thread_index, now, vm);
               goto trace1;
+            }
 
           if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
             {
@@ -983,6 +1134,8 @@ snat_out2in_node_fn (vlib_main_t * vm,
 
          b0 = vlib_get_buffer (vm, bi0);
 
+          vnet_buffer (b0)->snat.flags = 0;
+
           ip0 = vlib_buffer_get_current (b0);
           udp0 = ip4_next_header (ip0);
           tcp0 = (tcp_header_t *) udp0;
@@ -995,7 +1148,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
           proto0 = ip_proto_to_snat_proto (ip0->protocol);
 
           if (PREDICT_FALSE (proto0 == ~0))
+            {
+              snat_out2in_unknown_proto(sm, b0, ip0, rx_fib_index0,
+                                        thread_index, now, vm);
               goto trace00;
+            }
 
           if (PREDICT_FALSE(ip0->ttl == 1))
             {
@@ -1168,7 +1325,7 @@ snat_det_out2in_node_fn (vlib_main_t * vm,
   snat_out2in_next_t next_index;
   u32 pkts_processed = 0;
   snat_main_t * sm = &snat_main;
-  u32 thread_index = os_get_cpu_number ();
+  u32 thread_index = vlib_get_thread_index ();
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;