nat: move deterministic nat to det44 sub feature

Type: refactor

Change-Id: I0bb203102a0e13dd7448e2125925ab356bbd7937
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 130 insertions, 0 deletions

diff --git a/src/plugins/nat/det44/det44_inlines.h b/src/plugins/nat/det44/det44_inlines.h
new file mode 100644
index 00000000000..e4be469562c
--- /dev/null
+++ b/src/plugins/nat/det44/det44_inlines.h
@@ -0,0 +1,130 @@
+/*
+ * det44.h - deterministic NAT definitions
+ *
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @file
+ * @brief Deterministic NAT (CGN) inlines
+ */
+
+#ifndef __included_det44_inlines_h__
+#define __included_det44_inlines_h__
+
+static_always_inline int
+det44_is_interface_addr (vlib_node_runtime_t * node,
+			 u32 sw_if_index0, u32 ip4_addr)
+{
+  det44_runtime_t *rt = (det44_runtime_t *) node->runtime_data;
+  det44_main_t *dm = &det44_main;
+  ip4_address_t *first_int_addr;
+
+  if (PREDICT_FALSE (rt->cached_sw_if_index != sw_if_index0))
+    {
+      first_int_addr = ip4_interface_first_address (dm->ip4_main,
+						    sw_if_index0, 0);
+      rt->cached_sw_if_index = sw_if_index0;
+      if (first_int_addr)
+	rt->cached_ip4_address = first_int_addr->as_u32;
+      else
+	rt->cached_ip4_address = 0;
+    }
+  if (PREDICT_FALSE (rt->cached_ip4_address == ip4_addr))
+    return 0;
+  return 1;
+}
+
+/**
+ * @brief Check if packet should be translated
+ *
+ * Packets aimed at outside interface and external address with active session
+ * should be translated.
+ *
+ * @param node          NAT runtime data
+ * @param sw_if_index0  index of the inside interface
+ * @param ip0           IPv4 header
+ * @param proto0        NAT protocol
+ * @param rx_fib_index0 RX FIB index
+ *
+ * @returns 0 if packet should be translated otherwise 1
+ */
+static_always_inline int
+det44_translate (vlib_node_runtime_t * node, u32 sw_if_index0,
+		 ip4_header_t * ip0, u32 proto0, u32 rx_fib_index0)
+{
+  det44_main_t *dm = &det44_main;
+  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+  det44_fib_t *outside_fib;
+  fib_prefix_t pfx = {
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_len = 32,
+    .fp_addr = {
+		.ip4.as_u32 = ip0->dst_address.as_u32,
+		}
+    ,
+  };
+
+  /* Don't NAT packet aimed at the interface address */
+  if (PREDICT_FALSE (!det44_is_interface_addr (node, sw_if_index0,
+					       ip0->dst_address.as_u32)))
+    {
+      return 1;
+    }
+
+  /* find out if there is outside feature enabled for this destination */
+  fei = fib_table_lookup (rx_fib_index0, &pfx);
+  if (FIB_NODE_INDEX_INVALID != fei)
+    {
+      u32 sw_if_index = fib_entry_get_resolving_interface (fei);
+      if (sw_if_index == ~0)
+	{
+	  // TODO: go over use cases
+          /* *INDENT-OFF* */
+	  vec_foreach (outside_fib, dm->outside_fibs)
+	    {
+	      fei = fib_table_lookup (outside_fib->fib_index, &pfx);
+	      if (FIB_NODE_INDEX_INVALID != fei)
+	        {
+		  sw_if_index = fib_entry_get_resolving_interface (fei);
+		  if (sw_if_index != ~0)
+		    break;
+	        }
+	    }
+          /* *INDENT-ON* */
+	}
+      if (sw_if_index != ~0)
+	{
+	  det44_interface_t *i;
+          /* *INDENT-OFF* */
+          pool_foreach (i, dm->interfaces, ({
+            /* NAT packet aimed at outside interface */
+	    if ((det44_interface_is_outside (i)) && (sw_if_index == i->sw_if_index))
+              return 0;
+          }));
+          /* *INDENT-ON* */
+	}
+    }
+  return 1;
+}
+
+#endif /* __included_det44_inlines_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */