nat: Final NAT44 EI/ED split patch

This patch achieves complete separation of
endpoint-dependent and endpoint-independent IPv4 NAT
features. Some common stuff is also moved to NAT
library.

Type: refactor

Change-Id: I52468b7e2b5ac28958a2baf8e2ea01787322e801
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 362 insertions, 0 deletions

diff --git a/src/plugins/nat/nat44-ed/nat44_ed_classify.c b/src/plugins/nat/nat44-ed/nat44_ed_classify.c
new file mode 100644
index 00000000000..5a9f4e42657
--- /dev/null
+++ b/src/plugins/nat/nat44-ed/nat44_ed_classify.c
@@ -0,0 +1,362 @@
+/*
+ * Copyright (c) 2018 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 Classify for one armed NAT44 (in+out interface)
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/fib/ip4_fib.h>
+
+#include <nat/nat44-ed/nat44_ed.h>
+#include <nat/nat44-ed/nat44_ed_inlines.h>
+
+#define foreach_nat44_classify_error                      \
+_(NEXT_IN2OUT, "next in2out")                             \
+_(NEXT_OUT2IN, "next out2in")                             \
+_(FRAG_CACHED, "fragment cached")
+
+typedef enum
+{
+#define _(sym,str) NAT44_CLASSIFY_ERROR_##sym,
+  foreach_nat44_classify_error
+#undef _
+    NAT44_CLASSIFY_N_ERROR,
+} nat44_classify_error_t;
+
+typedef enum
+{
+  NAT44_CLASSIFY_NEXT_IN2OUT,
+  NAT44_CLASSIFY_NEXT_OUT2IN,
+  NAT44_CLASSIFY_NEXT_DROP,
+  NAT44_CLASSIFY_N_NEXT,
+} nat44_classify_next_t;
+
+typedef struct
+{
+  u8 next_in2out;
+  u8 cached;
+} nat44_classify_trace_t;
+
+static u8 *
+format_nat44_classify_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  nat44_classify_trace_t *t = va_arg (*args, nat44_classify_trace_t *);
+  char *next;
+
+  if (t->cached)
+    s = format (s, "nat44-classify: fragment cached");
+  else
+    {
+      next = t->next_in2out ? "nat44-ed-in2out" : "nat44-ed-out2in";
+      s = format (s, "nat44-classify: next %s", next);
+    }
+
+  return s;
+}
+
+static inline uword
+nat44_handoff_classify_node_fn_inline (vlib_main_t * vm,
+				       vlib_node_runtime_t * node,
+				       vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  nat44_classify_next_t next_index;
+  snat_main_t *sm = &snat_main;
+  snat_static_mapping_t *m;
+  u32 next_in2out = 0, next_out2in = 0;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  u32 next0 = NAT_NEXT_IN2OUT_CLASSIFY;
+	  ip4_header_t *ip0;
+	  snat_address_t *ap;
+	  clib_bihash_kv_8_8_t kv0, value0;
+
+	  /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ip0 = vlib_buffer_get_current (b0);
+
+          vec_foreach (ap, sm->addresses)
+            {
+              if (ip0->dst_address.as_u32 == ap->addr.as_u32)
+                {
+                  next0 = NAT_NEXT_OUT2IN_CLASSIFY;
+                  goto enqueue0;
+                }
+            }
+
+	  if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
+	    {
+	      init_nat_k (&kv0, ip0->dst_address, 0, 0, 0);
+	      /* try to classify the fragment based on IP header alone */
+	      if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
+					   &kv0, &value0))
+		{
+		  m = pool_elt_at_index (sm->static_mappings, value0.value);
+		  if (m->local_addr.as_u32 != m->external_addr.as_u32)
+		    next0 = NAT_NEXT_OUT2IN_CLASSIFY;
+		  goto enqueue0;
+		}
+	      init_nat_k (&kv0, ip0->dst_address,
+			  vnet_buffer (b0)->ip.reass.l4_dst_port, 0,
+			  ip_proto_to_nat_proto (ip0->protocol));
+	      if (!clib_bihash_search_8_8
+		  (&sm->static_mapping_by_external, &kv0, &value0))
+		{
+		  m = pool_elt_at_index (sm->static_mappings, value0.value);
+		  if (m->local_addr.as_u32 != m->external_addr.as_u32)
+		    next0 = NAT_NEXT_OUT2IN_CLASSIFY;
+		}
+	    }
+
+	enqueue0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      nat44_classify_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->cached = 0;
+	      t->next_in2out = next0 == NAT_NEXT_IN2OUT_CLASSIFY ? 1 : 0;
+	    }
+
+	  next_in2out += next0 == NAT_NEXT_IN2OUT_CLASSIFY;
+	  next_out2in += next0 == NAT_NEXT_OUT2IN_CLASSIFY;
+
+	  /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, node->node_index,
+			       NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out);
+  vlib_node_increment_counter (vm, node->node_index,
+			       NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in);
+  return frame->n_vectors;
+}
+
+static inline uword
+nat44_ed_classify_node_fn_inline (vlib_main_t * vm,
+				  vlib_node_runtime_t * node,
+				  vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  nat44_classify_next_t next_index;
+  snat_main_t *sm = &snat_main;
+  snat_static_mapping_t *m;
+  u32 next_in2out = 0, next_out2in = 0;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  u32 next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
+	  u32 sw_if_index0, rx_fib_index0;
+	  ip4_header_t *ip0;
+	  snat_address_t *ap;
+	  clib_bihash_kv_8_8_t kv0, value0;
+	  clib_bihash_kv_16_8_t ed_kv0, ed_value0;
+
+	  /* speculatively enqueue b0 to the current next frame */
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ip0 = vlib_buffer_get_current (b0);
+
+	  u32 arc_next;
+	  vnet_feature_next (&arc_next, b0);
+	  vnet_buffer2 (b0)->nat.arc_next = arc_next;
+
+	  if (ip0->protocol != IP_PROTOCOL_ICMP)
+	    {
+	      /* process leading fragment/whole packet (with L4 header) */
+	      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      rx_fib_index0 =
+		fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
+						     sw_if_index0);
+	      init_ed_k (&ed_kv0, ip0->src_address,
+			 vnet_buffer (b0)->ip.reass.l4_src_port,
+			 ip0->dst_address,
+			 vnet_buffer (b0)->ip.reass.l4_dst_port,
+			 rx_fib_index0, ip0->protocol);
+	      /* process whole packet */
+	      if (!clib_bihash_search_16_8 (&sm->flow_hash, &ed_kv0,
+					    &ed_value0))
+		{
+		  ASSERT (vm->thread_index ==
+			  ed_value_get_thread_index (&ed_value0));
+		  snat_main_per_thread_data_t *tsm =
+		    &sm->per_thread_data[vm->thread_index];
+		  snat_session_t *s = pool_elt_at_index (
+		    tsm->sessions, ed_value_get_session_index (&ed_value0));
+		  clib_bihash_kv_16_8_t i2o_kv;
+		  nat_6t_flow_to_ed_k (&i2o_kv, &s->i2o);
+		  vnet_buffer2 (b0)->nat.cached_session_index =
+		    ed_value_get_session_index (&ed_value0);
+		  if (i2o_kv.key[0] == ed_kv0.key[0] &&
+		      i2o_kv.key[1] == ed_kv0.key[1])
+		    {
+		      next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
+		    }
+		  else
+		    {
+		      next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
+		    }
+
+		  goto enqueue0;
+		}
+	      /* session doesn't exist so continue in code */
+	    }
+
+          vec_foreach (ap, sm->addresses)
+            {
+              if (ip0->dst_address.as_u32 == ap->addr.as_u32)
+                {
+                  next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
+                  goto enqueue0;
+                }
+            }
+
+	  if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
+	    {
+	      init_nat_k (&kv0, ip0->dst_address, 0, 0, 0);
+	      /* try to classify the fragment based on IP header alone */
+	      if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
+					   &kv0, &value0))
+		{
+		  m = pool_elt_at_index (sm->static_mappings, value0.value);
+		  if (m->local_addr.as_u32 != m->external_addr.as_u32)
+		    next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
+		  goto enqueue0;
+		}
+	      init_nat_k (&kv0, ip0->dst_address,
+			  vnet_buffer (b0)->ip.reass.l4_dst_port, 0,
+			  ip_proto_to_nat_proto (ip0->protocol));
+	      if (!clib_bihash_search_8_8
+		  (&sm->static_mapping_by_external, &kv0, &value0))
+		{
+		  m = pool_elt_at_index (sm->static_mappings, value0.value);
+		  if (m->local_addr.as_u32 != m->external_addr.as_u32)
+		    next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH;
+		}
+	    }
+
+	enqueue0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      nat44_classify_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->cached = 0;
+	      t->next_in2out = next0 == NAT_NEXT_IN2OUT_ED_FAST_PATH ? 1 : 0;
+	    }
+
+	  next_in2out += next0 == NAT_NEXT_IN2OUT_ED_FAST_PATH;
+	  next_out2in += next0 == NAT_NEXT_OUT2IN_ED_FAST_PATH;
+
+	  /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  vlib_node_increment_counter (vm, node->node_index,
+			       NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out);
+  vlib_node_increment_counter (vm, node->node_index,
+			       NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in);
+  return frame->n_vectors;
+}
+
+VLIB_NODE_FN (nat44_ed_classify_node) (vlib_main_t * vm,
+				       vlib_node_runtime_t * node,
+				       vlib_frame_t * frame)
+{
+  return nat44_ed_classify_node_fn_inline (vm, node, frame);
+}
+
+VLIB_REGISTER_NODE (nat44_ed_classify_node) = {
+  .name = "nat44-ed-classify",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat44_classify_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+};
+
+VLIB_NODE_FN (nat44_handoff_classify_node) (vlib_main_t * vm,
+					    vlib_node_runtime_t * node,
+					    vlib_frame_t * frame)
+{
+  return nat44_handoff_classify_node_fn_inline (vm, node, frame);
+}
+
+VLIB_REGISTER_NODE (nat44_handoff_classify_node) = {
+  .name = "nat44-handoff-classify",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat44_classify_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */