Add basic support for DS-Lite CE (VPP-1059)

Change-Id: Ifcca60da3f77c0a4959f98b3365c846badbdc2d0
Signed-off-by: Juraj Sloboda <jsloboda@cisco.com>

1 files changed, 138 insertions, 0 deletions

diff --git a/src/plugins/nat/dslite_ce_encap.c b/src/plugins/nat/dslite_ce_encap.c
new file mode 100644
index 00000000000..f098d75ca70
--- /dev/null
+++ b/src/plugins/nat/dslite_ce_encap.c
@@ -0,0 +1,138 @@
+/*
+ * 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.
+ */
+#include <nat/dslite.h>
+
+vlib_node_registration_t dslite_ce_encap_node;
+
+typedef enum
+{
+  DSLITE_CE_ENCAP_NEXT_IP6_LOOKUP,
+  DSLITE_CE_ENCAP_NEXT_DROP,
+  DSLITE_CE_ENCAP_N_NEXT,
+} dslite_ce_encap_next_t;
+
+static char *dslite_ce_encap_error_strings[] = {
+#define _(sym,string) string,
+  foreach_dslite_error
+#undef _
+};
+
+static uword
+dslite_ce_encap_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+			 vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  dslite_ce_encap_next_t next_index;
+  dslite_main_t *dm = &dslite_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 = DSLITE_CE_ENCAP_NEXT_IP6_LOOKUP;
+	  u8 error0 = DSLITE_ERROR_CE_ENCAP;
+	  ip4_header_t *ip40;
+	  ip6_header_t *ip60;
+	  u32 proto0;
+
+	  /* 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);
+	  proto0 = ip_proto_to_snat_proto (ip40->protocol);
+
+	  if (PREDICT_FALSE (proto0 == ~0))
+	    {
+	      error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
+	      next0 = DSLITE_CE_ENCAP_NEXT_DROP;
+	      goto trace0;
+	    }
+
+	  /* Construct IPv6 header */
+	  vlib_buffer_advance (b0, -(sizeof (ip6_header_t)));
+	  ip60 = vlib_buffer_get_current (b0);
+	  ip60->ip_version_traffic_class_and_flow_label =
+	    clib_host_to_net_u32 ((6 << 28) + (ip40->tos << 20));
+	  ip60->payload_length = ip40->length;
+	  ip60->protocol = IP_PROTOCOL_IP_IN_IP;
+	  ip60->hop_limit = ip40->ttl;
+	  ip60->dst_address.as_u64[0] = dm->aftr_ip6_addr.as_u64[0];
+	  ip60->dst_address.as_u64[1] = dm->aftr_ip6_addr.as_u64[1];
+	  ip60->src_address.as_u64[0] = dm->b4_ip6_addr.as_u64[0];
+	  ip60->src_address.as_u64[1] = dm->b4_ip6_addr.as_u64[1];
+
+	trace0:
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->next_index = next0;
+	    }
+
+	  b0->error = node->errors[error0];
+
+	  /* 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);
+    }
+
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (dslite_ce_encap_node) = {
+  .function = dslite_ce_encap_node_fn,
+  .name = "dslite-ce-encap",
+  .vector_size = sizeof (u32),
+  .format_trace = format_dslite_ce_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (dslite_ce_encap_error_strings),
+  .error_strings = dslite_ce_encap_error_strings,
+  .n_next_nodes = DSLITE_CE_ENCAP_N_NEXT,
+  /* edit / add dispositions here */
+  .next_nodes = {
+    [DSLITE_CE_ENCAP_NEXT_DROP] = "error-drop",
+    [DSLITE_CE_ENCAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (dslite_ce_encap_node, dslite_ce_encap_node_fn);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */