NAT66 1:1 mapping (VPP-1108)

Support the 1:1 translation of source address for IPv6

Change-Id: I934d18e5ec508bf7422d796ee5f172b79c048011
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 225 insertions, 0 deletions

diff --git a/src/plugins/nat/nat66_out2in.c b/src/plugins/nat/nat66_out2in.c
new file mode 100644
index 00000000000..a28a4c3ade5
--- /dev/null
+++ b/src/plugins/nat/nat66_out2in.c
@@ -0,0 +1,225 @@
+/*
+ * 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 NAT66 outside to inside network translation
+ */
+
+#include <nat/nat66.h>
+#include <vnet/ip/ip6_to_ip4.h>
+#include <vnet/fib/fib_table.h>
+
+typedef struct
+{
+  u32 sw_if_index;
+  u32 next_index;
+} nat66_out2in_trace_t;
+
+static u8 *
+format_nat66_out2in_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 *);
+  nat66_out2in_trace_t *t = va_arg (*args, nat66_out2in_trace_t *);
+
+  s =
+    format (s, "NAT66-out2in: sw_if_index %d, next index %d", t->sw_if_index,
+	    t->next_index);
+
+  return s;
+}
+
+vlib_node_registration_t nat66_out2in_node;
+
+#define foreach_nat66_out2in_error                       \
+_(OUT2IN_PACKETS, "good out2in packets processed")       \
+_(NO_TRANSLATION, "no translation")                      \
+_(UNKNOWN, "unknown")
+
+typedef enum
+{
+#define _(sym,str) NAT66_OUT2IN_ERROR_##sym,
+  foreach_nat66_out2in_error
+#undef _
+    NAT66_OUT2IN_N_ERROR,
+} nat66_out2in_error_t;
+
+static char *nat66_out2in_error_strings[] = {
+#define _(sym,string) string,
+  foreach_nat66_out2in_error
+#undef _
+};
+
+typedef enum
+{
+  NAT66_OUT2IN_NEXT_IP6_LOOKUP,
+  NAT66_OUT2IN_NEXT_DROP,
+  NAT66_OUT2IN_N_NEXT,
+} nat66_out2in_next_t;
+
+static inline uword
+nat66_out2in_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		      vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  nat66_out2in_next_t next_index;
+  u32 pkts_processed = 0;
+  u32 thread_index = vlib_get_thread_index ();
+  nat66_main_t *nm = &nat66_main;
+
+  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 = NAT66_OUT2IN_NEXT_IP6_LOOKUP;
+	  ip6_header_t *ip60;
+	  u16 l4_offset0, frag_offset0;
+	  u8 l4_protocol0;
+	  nat66_static_mapping_t *sm0;
+	  u32 sw_if_index0, fib_index0;
+	  udp_header_t *udp0;
+	  tcp_header_t *tcp0;
+	  icmp46_header_t *icmp0;
+	  u16 *checksum0 = 0;
+	  ip_csum_t csum0;
+
+	  /* 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);
+	  ip60 = vlib_buffer_get_current (b0);
+
+	  if (PREDICT_FALSE
+	      (ip6_parse
+	       (ip60, b0->current_length, &l4_protocol0, &l4_offset0,
+		&frag_offset0)))
+	    {
+	      next0 = NAT66_OUT2IN_NEXT_DROP;
+	      b0->error = node->errors[NAT66_OUT2IN_ERROR_UNKNOWN];
+	      goto trace0;
+	    }
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  fib_index0 =
+	    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6,
+						 sw_if_index0);
+
+	  sm0 = nat66_static_mapping_get (&ip60->dst_address, fib_index0, 0);
+	  if (PREDICT_FALSE (!sm0))
+	    {
+	      goto trace0;
+	    }
+
+	  if (l4_protocol0 == IP_PROTOCOL_UDP)
+	    {
+	      udp0 = (udp_header_t *) u8_ptr_add (ip60, l4_offset0);
+	      checksum0 = &udp0->checksum;
+	    }
+	  else if (l4_protocol0 == IP_PROTOCOL_TCP)
+	    {
+	      tcp0 = (tcp_header_t *) u8_ptr_add (ip60, l4_offset0);
+	      checksum0 = &tcp0->checksum;
+	    }
+	  else if (l4_protocol0 == IP_PROTOCOL_ICMP6)
+	    {
+	      icmp0 = (icmp46_header_t *) u8_ptr_add (ip60, l4_offset0);
+	      checksum0 = &icmp0->checksum;
+	    }
+	  else
+	    goto skip_csum0;
+
+	  csum0 = ip_csum_sub_even (*checksum0, ip60->dst_address.as_u64[0]);
+	  csum0 = ip_csum_sub_even (csum0, ip60->dst_address.as_u64[1]);
+	  csum0 = ip_csum_add_even (csum0, sm0->l_addr.as_u64[0]);
+	  csum0 = ip_csum_add_even (csum0, sm0->l_addr.as_u64[1]);
+	  *checksum0 = ip_csum_fold (csum0);
+
+	skip_csum0:
+	  ip60->dst_address.as_u64[0] = sm0->l_addr.as_u64[0];
+	  ip60->dst_address.as_u64[1] = sm0->l_addr.as_u64[1];
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm0->fib_index;
+
+	  vlib_increment_combined_counter (&nm->session_counters,
+					   thread_index, sm0 - nm->sm, 1,
+					   vlib_buffer_length_in_chain (vm,
+									b0));
+
+	trace0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      nat66_out2in_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->next_index = next0;
+	    }
+
+	  pkts_processed += next0 != NAT66_OUT2IN_NEXT_DROP;
+
+	  /* 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, nat66_out2in_node.index,
+			       NAT66_OUT2IN_ERROR_OUT2IN_PACKETS,
+			       pkts_processed);
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat66_out2in_node) = {
+  .function = nat66_out2in_node_fn,
+  .name = "nat66-out2in",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nat66_out2in_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat66_out2in_error_strings),
+  .error_strings = nat66_out2in_error_strings,
+  .n_next_nodes = NAT66_OUT2IN_N_NEXT,
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [NAT66_OUT2IN_NEXT_DROP] = "error-drop",
+    [NAT66_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (nat66_out2in_node, nat66_out2in_node_fn);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */