NAT64: Add NAT64 support for snat plugin (VPP-699)

Basic NAT64 feature (no hairpinning, no multi-thread).

Change-Id: I392fccbce93e70c117f4a9a7ec7cf08d6c537f2d
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 348 insertions, 0 deletions

diff --git a/src/plugins/snat/nat64_out2in.c b/src/plugins/snat/nat64_out2in.c
new file mode 100644
index 00000000000..3eed9974af2
--- /dev/null
+++ b/src/plugins/snat/nat64_out2in.c
@@ -0,0 +1,348 @@
+/*
+ * Copyright (c) 2017 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 NAT64 IPv4 to IPv6 translation (otside to inside network)
+ */
+
+#include <snat/nat64.h>
+#include <vnet/ip/ip4_to_ip6.h>
+#include <vnet/fib/ip4_fib.h>
+
+/* *INDENT-OFF* */
+static u8 well_known_prefix[] = {
+  0x00, 0x64, 0xff, 0x9b,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00
+ };
+/* *INDENT-ON* */
+typedef struct
+{
+  u32 sw_if_index;
+  u32 next_index;
+} nat64_out2in_trace_t;
+
+static u8 *
+format_nat64_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 *);
+  nat64_out2in_trace_t *t = va_arg (*args, nat64_out2in_trace_t *);
+
+  s =
+    format (s, "NAT64-out2in: sw_if_index %d, next index %d", t->sw_if_index,
+	    t->next_index);
+
+  return s;
+}
+
+vlib_node_registration_t nat64_out2in_node;
+
+#define foreach_nat64_out2in_error                 \
+_(UNSUPPORTED_PROTOCOL, "Unsupported protocol")    \
+_(OUT2IN_PACKETS, "Good out2in packets processed") \
+_(NO_TRANSLATION, "No translation")                \
+_(UNKNOWN, "unknown")
+
+typedef enum
+{
+#define _(sym,str) NAT64_OUT2IN_ERROR_##sym,
+  foreach_nat64_out2in_error
+#undef _
+    NAT64_OUT2IN_N_ERROR,
+} nat64_out2in_error_t;
+
+static char *nat64_out2in_error_strings[] = {
+#define _(sym,string) string,
+  foreach_nat64_out2in_error
+#undef _
+};
+
+typedef enum
+{
+  NAT64_OUT2IN_NEXT_LOOKUP,
+  NAT64_OUT2IN_NEXT_DROP,
+  NAT64_OUT2IN_N_NEXT,
+} nat64_out2in_next_t;
+
+typedef struct nat64_out2in_set_ctx_t_
+{
+  vlib_buffer_t *b;
+  vlib_main_t *vm;
+} nat64_out2in_set_ctx_t;
+
+static int
+nat64_out2in_tcp_udp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
+			     void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_out2in_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  ip6_address_t ip6_saddr;
+  udp_header_t *udp = ip4_next_header (ip4);
+  snat_protocol_t proto = ip_proto_to_snat_proto (ip4->protocol);
+  u16 dport = udp->dst_port;
+  u16 sport = udp->src_port;
+  u32 sw_if_index, fib_index;
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  saddr.ip4.as_u32 = ip4->src_address.as_u32;
+  memset (&daddr, 0, sizeof (daddr));
+  daddr.ip4.as_u32 = ip4->dst_address.as_u32;
+
+  memcpy (&ip6_saddr, well_known_prefix, sizeof (ip6_saddr));
+  ip6_saddr.as_u32[3] = ip4->src_address.as_u32;
+
+  ste =
+    nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto,
+			    fib_index, 0);
+  if (ste)
+    {
+      bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index);
+      if (!bibe)
+	return -1;
+    }
+  else
+    {
+      bibe =
+	nat64_db_bib_entry_find (&nm->db, &daddr, dport, proto, fib_index, 0);
+
+      if (!bibe)
+	return -1;
+
+      ste =
+	nat64_db_st_entry_create (&nm->db, bibe, &ip6_saddr, &saddr.ip4,
+				  sport);
+    }
+
+  nat64_session_reset_timeout (ste, ctx->vm);
+
+  ip6->src_address.as_u64[0] = ip6_saddr.as_u64[0];
+  ip6->src_address.as_u64[1] = ip6_saddr.as_u64[1];
+
+  ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+  ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+  udp->dst_port = bibe->in_port;
+
+  return 0;
+}
+
+static int
+nat64_out2in_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
+{
+  nat64_main_t *nm = &nat64_main;
+  nat64_out2in_set_ctx_t *ctx = arg;
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_st_entry_t *ste;
+  ip46_address_t saddr, daddr;
+  ip6_address_t ip6_saddr;
+  u32 sw_if_index, fib_index;
+  icmp46_header_t *icmp = ip4_next_header (ip4);
+
+  sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
+  fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  memset (&saddr, 0, sizeof (saddr));
+  saddr.ip4.as_u32 = ip4->src_address.as_u32;
+  memset (&daddr, 0, sizeof (daddr));
+  daddr.ip4.as_u32 = ip4->dst_address.as_u32;
+
+  memcpy (&ip6_saddr, well_known_prefix, sizeof (ip6_saddr));
+  ip6_saddr.as_u32[3] = ip4->src_address.as_u32;
+
+  if (icmp->type == ICMP6_echo_request || icmp->type == ICMP6_echo_reply)
+    {
+      u16 out_id = ((u16 *) (icmp))[2];
+      ste =
+	nat64_db_st_entry_find (&nm->db, &daddr, &saddr, out_id, 0,
+				SNAT_PROTOCOL_ICMP, fib_index, 0);
+
+      if (ste)
+	{
+	  bibe =
+	    nat64_db_bib_entry_by_index (&nm->db, SNAT_PROTOCOL_ICMP,
+					 ste->bibe_index);
+	  if (!bibe)
+	    return -1;
+	}
+      else
+	{
+	  bibe =
+	    nat64_db_bib_entry_find (&nm->db, &daddr, out_id,
+				     SNAT_PROTOCOL_ICMP, fib_index, 0);
+	  if (!bibe)
+	    return -1;
+
+	  ste =
+	    nat64_db_st_entry_create (&nm->db, bibe, &ip6_saddr, &saddr.ip4,
+				      0);
+	}
+
+      nat64_session_reset_timeout (ste, ctx->vm);
+
+      ip6->src_address.as_u64[0] = ip6_saddr.as_u64[0];
+      ip6->src_address.as_u64[1] = ip6_saddr.as_u64[1];
+
+      ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
+      ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
+      ((u16 *) (icmp))[2] = bibe->in_port;
+
+    }
+  else
+    {
+      //TODO: ICMP error
+      clib_warning ("not ICMP echo request/reply, %u", icmp->type);
+      return -1;
+    }
+
+  return 0;
+}
+
+static int
+nat64_out2in_inner_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
+				void *ctx)
+{
+  //TODO:
+  return -1;
+}
+
+static uword
+nat64_out2in_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		      vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  nat64_out2in_next_t next_index;
+  u32 pkts_processed = 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;
+	  ip4_header_t *ip40;
+	  u32 proto0;
+	  nat64_out2in_set_ctx_t ctx0;
+
+	  /* 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);
+	  ip40 = vlib_buffer_get_current (b0);
+
+	  ctx0.b = b0;
+	  ctx0.vm = vm;
+
+	  next0 = NAT64_OUT2IN_NEXT_LOOKUP;
+
+	  proto0 = ip_proto_to_snat_proto (ip40->protocol);
+	  if (PREDICT_FALSE (proto0 == ~0))
+	    {
+	      next0 = NAT64_OUT2IN_NEXT_DROP;
+	      b0->error =
+		node->errors[NAT64_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
+	      goto trace0;
+	    }
+
+	  if (proto0 == SNAT_PROTOCOL_ICMP)
+	    {
+	      if (icmp_to_icmp6
+		  (b0, nat64_out2in_icmp_set_cb, &ctx0,
+		   nat64_out2in_inner_icmp_set_cb, &ctx0))
+		{
+		  next0 = NAT64_OUT2IN_NEXT_DROP;
+		  b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+	  else
+	    {
+	      if (ip4_to_ip6_tcp_udp (b0, nat64_out2in_tcp_udp_set_cb, &ctx0))
+		{
+		  next0 = NAT64_OUT2IN_NEXT_DROP;
+		  b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
+		  goto trace0;
+		}
+	    }
+
+	trace0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      nat64_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 != NAT64_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, nat64_out2in_node.index,
+			       NAT64_OUT2IN_ERROR_OUT2IN_PACKETS,
+			       pkts_processed);
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat64_out2in_node) = {
+  .function = nat64_out2in_node_fn,
+  .name = "nat64-out2in",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nat64_out2in_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat64_out2in_error_strings),
+  .error_strings = nat64_out2in_error_strings,.n_next_nodes = 2,
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [NAT64_OUT2IN_NEXT_DROP] = "error-drop",
+    [NAT64_OUT2IN_NEXT_LOOKUP] = "ip6-lookup",
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_node, nat64_out2in_node_fn);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */