SRv6 masquerading proxy plugin

Change-Id: Ia65cf2c7b7fdf84c64e60af4cc815251022c53a9
Signed-off-by: Francois Clad <fclad@cisco.com>

1 files changed, 355 insertions, 0 deletions

diff --git a/src/plugins/srv6-am/node.c b/src/plugins/srv6-am/node.c
new file mode 100644
index 00000000000..8643aa42532
--- /dev/null
+++ b/src/plugins/srv6-am/node.c
@@ -0,0 +1,355 @@
+/*
+ * Copyright (c) 2015 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 <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vppinfra/error.h>
+#include <srv6-am/am.h>
+
+
+/******************************* Packet tracing *******************************/
+
+typedef struct
+{
+  u32 localsid_index;
+} srv6_am_localsid_trace_t;
+
+typedef struct
+{
+  ip6_address_t src, dst;
+} srv6_am_rewrite_trace_t;
+
+static u8 *
+format_srv6_am_localsid_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 *);
+  srv6_am_localsid_trace_t *t = va_arg (*args, srv6_am_localsid_trace_t *);
+
+  return format (s, "SRv6-AM-localsid: localsid_index %d", t->localsid_index);
+}
+
+static u8 *
+format_srv6_am_rewrite_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 *);
+  srv6_am_rewrite_trace_t *t = va_arg (*args, srv6_am_rewrite_trace_t *);
+
+  return format (s, "SRv6-AM-rewrite: src %U dst %U",
+		 format_ip6_address, &t->src, format_ip6_address, &t->dst);
+}
+
+
+/***************************** Node registration ******************************/
+
+vlib_node_registration_t srv6_am_rewrite_node;
+
+
+/****************************** Packet counters *******************************/
+
+#define foreach_srv6_am_rewrite_counter \
+_(PROCESSED, "srv6-am rewritten packets") \
+_(NO_SRH, "(Error) No SRH.")
+
+typedef enum
+{
+#define _(sym,str) SRV6_AM_REWRITE_COUNTER_##sym,
+  foreach_srv6_am_rewrite_counter
+#undef _
+    SRV6_AM_REWRITE_N_COUNTERS,
+} srv6_am_rewrite_counters;
+
+static char *srv6_am_rewrite_counter_strings[] = {
+#define _(sym,string) string,
+  foreach_srv6_am_rewrite_counter
+#undef _
+};
+
+
+/********************************* Next nodes *********************************/
+
+typedef enum
+{
+  SRV6_AM_LOCALSID_NEXT_ERROR,
+  SRV6_AM_LOCALSID_NEXT_REWRITE,
+  SRV6_AM_LOCALSID_N_NEXT,
+} srv6_am_localsid_next_t;
+
+typedef enum
+{
+  SRV6_AM_REWRITE_NEXT_ERROR,
+  SRV6_AM_REWRITE_NEXT_LOOKUP,
+  SRV6_AM_REWRITE_N_NEXT,
+} srv6_am_rewrite_next_t;
+
+
+/******************************* Local SID node *******************************/
+
+/**
+ * @brief SRv6 masquerading.
+ */
+static_always_inline void
+end_am_processing (vlib_buffer_t * b0,
+		   ip6_header_t * ip0,
+		   ip6_sr_header_t * sr0,
+		   ip6_sr_localsid_t * ls0, u32 * next0)
+{
+  ip6_address_t *new_dst0;
+
+  if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_IPV6_ROUTE ||
+		     sr0->type != ROUTING_HEADER_TYPE_SR))
+    {
+      *next0 = SRV6_AM_LOCALSID_NEXT_ERROR;
+      return;
+    }
+
+  if (PREDICT_FALSE (sr0->segments_left == 0))
+    {
+      *next0 = SRV6_AM_LOCALSID_NEXT_ERROR;
+      return;
+    }
+
+  /* Decrement Segments Left */
+  sr0->segments_left -= 1;
+
+  /* Set Destination Address to Last Segment (index 0) */
+  new_dst0 = (ip6_address_t *) (sr0->segments);
+  ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
+  ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
+
+  /* Set Xconnect adjacency to VNF */
+  vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
+}
+
+/**
+ * @brief Graph node for applying SRv6 masquerading.
+ */
+static uword
+srv6_am_localsid_fn (vlib_main_t * vm,
+		     vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  ip6_sr_main_t *sm = &sr_main;
+  u32 n_left_from, next_index, *from, *to_next;
+  u32 cnt_packets = 0;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+
+  u32 thread_index = vlib_get_thread_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);
+
+      /* TODO: Dual/quad loop */
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  ip6_header_t *ip0 = 0;
+	  ip6_sr_header_t *sr0;
+	  ip6_sr_localsid_t *ls0;
+	  u32 next0 = SRV6_AM_LOCALSID_NEXT_REWRITE;
+
+	  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);
+	  sr0 = (ip6_sr_header_t *) (ip0 + 1);
+
+	  /* Lookup the SR End behavior based on IP DA (adj) */
+	  ls0 = pool_elt_at_index (sm->localsids,
+				   vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
+
+	  /* SRH processing */
+	  end_am_processing (b0, ip0, sr0, ls0, &next0);
+
+	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      srv6_am_localsid_trace_t *tr =
+		vlib_add_trace (vm, node, b0, sizeof *tr);
+	      tr->localsid_index = ls0 - sm->localsids;
+	    }
+
+	  /* This increments the SRv6 per LocalSID counters. */
+	  vlib_increment_combined_counter (((next0 ==
+					     SRV6_AM_LOCALSID_NEXT_ERROR) ?
+					    &(sm->sr_ls_invalid_counters) :
+					    &(sm->sr_ls_valid_counters)),
+					   thread_index, ls0 - sm->localsids,
+					   1, vlib_buffer_length_in_chain (vm,
+									   b0));
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+
+	  cnt_packets++;
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (srv6_am_localsid_node) = {
+  .function = srv6_am_localsid_fn,
+  .name = "srv6-am-localsid",
+  .vector_size = sizeof (u32),
+  .format_trace = format_srv6_am_localsid_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_next_nodes = SRV6_AM_LOCALSID_N_NEXT,
+  .next_nodes = {
+    [SRV6_AM_LOCALSID_NEXT_REWRITE] = "ip6-rewrite",
+    [SRV6_AM_LOCALSID_NEXT_ERROR] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
+
+
+/******************************* Rewriting node *******************************/
+
+/**
+ * @brief SRv6 de-masquerading.
+ */
+static_always_inline void
+end_am_rewriting (vlib_node_runtime_t * node,
+		  vlib_buffer_t * b0,
+		  ip6_header_t * ip0, ip6_sr_header_t * sr0, u32 * next0)
+{
+  if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_IPV6_ROUTE ||
+		     sr0->type != ROUTING_HEADER_TYPE_SR))
+    {
+      b0->error = node->errors[SRV6_AM_REWRITE_COUNTER_NO_SRH];
+      *next0 = SRV6_AM_REWRITE_NEXT_ERROR;
+      return;
+    }
+
+  /* Restore Destination Address to active segment (index SL) */
+  if (sr0->segments_left != 0)
+    {
+      ip6_address_t *new_dst0;
+      new_dst0 = (ip6_address_t *) (sr0->segments) + sr0->segments_left;
+      ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
+      ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
+    }
+}
+
+/**
+ * @brief Graph node for applying SRv6 de-masquerading.
+ */
+static uword
+srv6_am_rewrite_fn (vlib_main_t * vm,
+		    vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, next_index, *from, *to_next;
+  u32 cnt_packets = 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);
+
+      /* TODO: Dual/quad loop */
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  ip6_header_t *ip0 = 0;
+	  ip6_sr_header_t *sr0;
+	  u32 next0 = SRV6_AM_REWRITE_NEXT_LOOKUP;
+
+	  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);
+	  sr0 = (ip6_sr_header_t *) (ip0 + 1);
+
+	  /* SRH processing */
+	  end_am_rewriting (node, b0, ip0, sr0, &next0);
+
+	  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
+	      PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      srv6_am_rewrite_trace_t *tr =
+		vlib_add_trace (vm, node, b0, sizeof *tr);
+	      clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
+			   sizeof tr->src.as_u8);
+	      clib_memcpy (tr->dst.as_u8, ip0->dst_address.as_u8,
+			   sizeof tr->dst.as_u8);
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+
+	  cnt_packets++;
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  /* Update counters */
+  vlib_node_increment_counter (vm, srv6_am_rewrite_node.index,
+			       SRV6_AM_REWRITE_COUNTER_PROCESSED,
+			       cnt_packets);
+
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (srv6_am_rewrite_node) = {
+  .function = srv6_am_rewrite_fn,
+  .name = "srv6-am-rewrite",
+  .vector_size = sizeof (u32),
+  .format_trace = format_srv6_am_rewrite_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = SRV6_AM_REWRITE_N_COUNTERS,
+  .error_strings = srv6_am_rewrite_counter_strings,
+  .n_next_nodes = SRV6_AM_REWRITE_N_NEXT,
+  .next_nodes = {
+      [SRV6_AM_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
+      [SRV6_AM_REWRITE_NEXT_ERROR] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
+
+/*
+* fd.io coding-style-patch-verification: ON
+*
+* Local Variables:
+* eval: (c-set-style "gnu")
+* End:
+*/