Initial Commit: VPP cicn VPP plugin

Change-Id: If1b965f0a4b7cfacda8f6caf6925072a9007ffb4
Signed-off-by: Jim Gibson <gibson@cisco.com>

1 files changed, 945 insertions, 0 deletions

diff --git a/cicn-plugin/cicn/cicn_pg.c b/cicn-plugin/cicn/cicn_pg.c
new file mode 100644
index 00000000..91bf1759
--- /dev/null
+++ b/cicn-plugin/cicn/cicn_pg.c
@@ -0,0 +1,945 @@
+/*
+ * 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.
+ */
+/*
+ * cicn_pg.c: VPP packet-generator ('pg') graph nodes and assorted utilities.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+
+#include <cicn/cicn.h>
+
+/* Registration struct for a graph node */
+vlib_node_registration_t icn_pg_node;
+
+/* Stats, which end up called "error" even though they aren't... */
+#define foreach_icnpg_error			\
+    _(PROCESSED, "ICN PG packets processed")	\
+    _(DROPPED, "ICN PG packets dropped") 	\
+    _(INTEREST_MSGS_GENERATED, "ICN PG Interests generated") \
+    _(CONTENT_MSGS_RECEIVED, "ICN PG Content msgs received") \
+    _(NACKS_RECEIVED, "ICN PG NACKs received")
+
+typedef enum
+{
+#define _(sym,str) ICNPG_ERROR_##sym,
+  foreach_icnpg_error
+#undef _
+    ICNPG_N_ERROR,
+} icnpg_error_t;
+
+static char *icnpg_error_strings[] = {
+#define _(sym,string) string,
+  foreach_icnpg_error
+#undef _
+};
+
+/* Next graph nodes, which reference the list in the actual registration
+ * block below
+ */
+typedef enum
+{
+  ICNPG_NEXT_LOOKUP,
+  ICNPG_NEXT_DROP,
+  ICNPG_N_NEXT,
+} icnpg_next_t;
+
+/* Trace context struct */
+typedef struct
+{
+  u32 next_index;
+  u32 sw_if_index;
+  u8 pkt_type;
+  u16 msg_type;
+} icnpg_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_icnpg_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 *);
+  icnpg_trace_t *t = va_arg (*args, icnpg_trace_t *);
+
+  s = format (s, "ICNPG: pkt: %d, msg %d, sw_if_index %d, next index %d",
+	      (int) t->pkt_type, (int) t->msg_type,
+	      t->sw_if_index, t->next_index);
+  return (s);
+}
+
+/*
+ * Node function for the icn packet-generator client. The goal here is to
+ * manipulate/tweak a stream of packets that have been injected by the
+ * vpp packet generator to generate icn request traffic.
+ */
+static uword
+icnpg_client_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		      vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  icnpg_next_t next_index;
+  u32 pkts_processed = 0, pkts_dropped = 0;
+  u32 interest_msgs_generated = 0, content_msgs_received = 0;
+  u32 nacks_received = 0;
+  uint64_t namecounter = 1LL;
+  u32 bi0, bi1;
+  vlib_buffer_t *b0, *b1;
+  u8 pkt_type0 = 0, pkt_type1 = 0;
+  u16 msg_type0 = 0, msg_type1 = 0;
+  cicn_pkt_hdr_desc_t pkt_hdr_desc0, pkt_hdr_desc1;
+  u8 *body0, *body1;
+  u32 len0, len1;
+  udp_header_t *udp0, *udp1;
+  ip4_header_t *ip0, *ip1;
+  uint8_t *name0, *name1;
+  uint32_t namelen0, namelen1;
+  cicn_main_t *sm = &cicn_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 >= 4 && n_left_to_next >= 2)
+	{
+	  u32 next0 = ICNPG_NEXT_DROP;
+	  u32 next1 = ICNPG_NEXT_DROP;
+	  u32 sw_if_index0, sw_if_index1;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t *p2, *p3;
+
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, (2 * CLIB_CACHE_LINE_BYTES), STORE);
+	    CLIB_PREFETCH (p3->data, (2 * CLIB_CACHE_LINE_BYTES), STORE);
+	  }
+
+	  /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+	  /* We think that the udp code has handed us the payloads,
+	   * so we need to walk back to the IP headers
+	   */
+	  ASSERT (b0->current_data >=
+		  (sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+	  ASSERT (b1->current_data >=
+		  (sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+	  body0 = vlib_buffer_get_current (b0);
+	  len0 = b0->current_length;
+
+	  body1 = vlib_buffer_get_current (b1);
+	  len1 = b1->current_length;
+
+	  vlib_buffer_advance (b0, -(sizeof (udp_header_t)));
+	  udp0 = vlib_buffer_get_current (b0);
+	  vlib_buffer_advance (b0, -(sizeof (ip4_header_t)));
+	  ip0 = vlib_buffer_get_current (b0);
+
+	  vlib_buffer_advance (b1, -(sizeof (udp_header_t)));
+	  udp1 = vlib_buffer_get_current (b1);
+	  vlib_buffer_advance (b1, -(sizeof (ip4_header_t)));
+	  ip1 = vlib_buffer_get_current (b1);
+
+	  /* Check icn packets, locate names */
+	  if (cicn_parse_pkt (body0, len0, &pkt_type0, &msg_type0,
+			      &name0, &namelen0, &pkt_hdr_desc0) == AOK)
+	    {
+
+	      if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_INTEREST) &&
+				(msg_type0 == CICN_MSG_TYPE_INTEREST)))
+		{
+		  /* Increment the appropriate message counter */
+		  interest_msgs_generated++;
+
+		  /* Stuff the counter value into the last name-comp */
+		  C_PUTINT64 ((name0 + namelen0 - 8), namecounter);
+		  namecounter += 1LL;
+
+		  /* Rewrite and send */
+
+		  /* Rewrite and send */
+		  ip0->src_address.as_u32 = sm->pgen_clt_src_addr;
+		  ip0->dst_address.as_u32 = sm->pgen_clt_dest_addr;
+
+		  ip0->checksum = ip4_header_checksum (ip0);
+
+		  udp0->src_port = sm->pgen_clt_src_port;
+		  udp0->dst_port = sm->pgen_clt_dest_port;
+		  udp0->checksum = 0;
+
+		  next0 = ICNPG_NEXT_LOOKUP;
+		}
+	      else if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_CONTENT) &&
+				     (msg_type0 == CICN_MSG_TYPE_CONTENT)))
+		{
+		  /* If we receive a content message, increment a counter */
+		  content_msgs_received++;
+		}
+	      else if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_NAK)))
+		{
+		  /* If we receive a NACK, just increment a counter */
+		  nacks_received++;
+		}
+	    }
+
+	  if (cicn_parse_pkt (body1, len1, &pkt_type1, &msg_type1,
+			      &name1, &namelen1, &pkt_hdr_desc1) == AOK)
+	    {
+	      if (PREDICT_TRUE ((pkt_type1 == CICN_PKT_TYPE_INTEREST) &&
+				(msg_type1 == CICN_MSG_TYPE_INTEREST)))
+		{
+		  /* Increment the appropriate message counter */
+		  interest_msgs_generated++;
+
+		  /* Stuff the counter value into the last name-comp */
+		  C_PUTINT64 ((name1 + namelen1 - 8), namecounter);
+		  namecounter += 1LL;
+
+		  /* Rewrite and send */
+
+		  /* Rewrite and send */
+		  ip1->src_address.as_u32 = sm->pgen_clt_src_addr;
+		  ip1->dst_address.as_u32 = sm->pgen_clt_dest_addr;
+
+		  ip1->checksum = ip4_header_checksum (ip0);
+
+		  udp1->src_port = sm->pgen_clt_src_port;
+		  udp1->dst_port = sm->pgen_clt_dest_port;
+		  udp1->checksum = 0;
+
+		  next1 = ICNPG_NEXT_LOOKUP;
+		}
+	      else if (PREDICT_TRUE ((pkt_type1 == CICN_PKT_TYPE_CONTENT) &&
+				     (msg_type1 == CICN_MSG_TYPE_CONTENT)))
+		{
+		  /* If we receive a content message, increment a counter */
+		  content_msgs_received++;
+		}
+	      else if (PREDICT_TRUE ((pkt_type1 == CICN_PKT_TYPE_NAK)))
+		{
+		  /* If we receive a NACK, just increment a counter */
+		  nacks_received++;
+		}
+	    }
+
+	  /* Send pkt to next node */
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
+	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = ~0;
+
+	  pkts_processed += 2;
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
+	    {
+	      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+		{
+		  icnpg_trace_t *t =
+		    vlib_add_trace (vm, node, b0, sizeof (*t));
+		  t->pkt_type = pkt_type0;
+		  t->msg_type = msg_type0;
+		  t->sw_if_index = sw_if_index0;
+		  t->next_index = next0;
+		}
+	      if (b1->flags & VLIB_BUFFER_IS_TRACED)
+		{
+		  icnpg_trace_t *t =
+		    vlib_add_trace (vm, node, b1, sizeof (*t));
+		  t->pkt_type = pkt_type1;
+		  t->msg_type = msg_type1;
+		  t->sw_if_index = sw_if_index1;
+		  t->next_index = next1;
+		}
+	    }
+
+	  if (next0 == ICNPG_NEXT_DROP)
+	    {
+	      pkts_dropped++;
+	    }
+	  if (next1 == ICNPG_NEXT_DROP)
+	    {
+	      pkts_dropped++;
+	    }
+
+	  /* verify speculative enqueues, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, bi1, next0, next1);
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 next0 = ICNPG_NEXT_DROP;
+	  u32 sw_if_index0;
+
+	  /* 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);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+	  /* We think that the udp code has handed us the payloads,
+	   * so we need to walk back to the IP headers
+	   */
+	  ASSERT (b0->current_data >=
+		  (sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+	  body0 = vlib_buffer_get_current (b0);
+	  len0 = b0->current_length;
+
+	  vlib_buffer_advance (b0, -(sizeof (udp_header_t)));
+	  udp0 = vlib_buffer_get_current (b0);
+	  vlib_buffer_advance (b0, -(sizeof (ip4_header_t)));
+	  ip0 = vlib_buffer_get_current (b0);
+
+	  /* Check icn packets, locate names */
+	  if (cicn_parse_pkt (body0, len0, &pkt_type0, &msg_type0,
+			      &name0, &namelen0, &pkt_hdr_desc0) == AOK)
+	    {
+
+	      if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_INTEREST) &&
+				(msg_type0 == CICN_MSG_TYPE_INTEREST)))
+		{
+		  /* Increment the appropriate message counter */
+		  interest_msgs_generated++;
+
+		  /* Stuff the counter value into the last name-comp */
+		  C_PUTINT64 ((name0 + namelen0 - 8), namecounter);
+		  namecounter += 1LL;
+
+		  /* Rewrite and send */
+		  ip0->src_address.as_u32 = sm->pgen_clt_src_addr;
+		  ip0->dst_address.as_u32 = sm->pgen_clt_dest_addr;
+
+		  ip0->checksum = ip4_header_checksum (ip0);
+
+		  udp0->src_port = sm->pgen_clt_src_port;
+		  udp0->dst_port = sm->pgen_clt_dest_port;
+		  udp0->checksum = 0;
+
+		  next0 = ICNPG_NEXT_LOOKUP;
+		}
+	      else if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_CONTENT) &&
+				     (msg_type0 == CICN_MSG_TYPE_CONTENT)))
+		{
+		  /* If we receive a content message, increment a counter */
+		  content_msgs_received++;
+		}
+	      else if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_NAK)))
+		{
+		  /* If we receive a NACK, just increment a counter */
+		  nacks_received++;
+		}
+	    }
+
+	  /* Send pkt to ip lookup */
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      icnpg_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->pkt_type = pkt_type0;
+	      t->msg_type = msg_type0;
+	      t->sw_if_index = sw_if_index0;
+	      t->next_index = next0;
+	    }
+
+	  pkts_processed += 1;
+
+	  if (next0 == ICNPG_NEXT_DROP)
+	    {
+	      pkts_dropped++;
+	    }
+
+	  /* 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, icn_pg_node.index,
+			       ICNPG_ERROR_PROCESSED, pkts_processed);
+  vlib_node_increment_counter (vm, icn_pg_node.index,
+			       ICNPG_ERROR_DROPPED, pkts_dropped);
+  vlib_node_increment_counter (vm, icn_pg_node.index,
+			       ICNPG_ERROR_INTEREST_MSGS_GENERATED,
+			       interest_msgs_generated);
+  vlib_node_increment_counter (vm, icn_pg_node.index,
+			       ICNPG_ERROR_CONTENT_MSGS_RECEIVED,
+			       content_msgs_received);
+  vlib_node_increment_counter (vm, icn_pg_node.index,
+			       ICNPG_ERROR_NACKS_RECEIVED, nacks_received);
+
+  return (frame->n_vectors);
+}
+
+
+VLIB_REGISTER_NODE (icn_pg_node) =
+{
+  .function = icnpg_client_node_fn,.name = "icnpg",.vector_size =
+    sizeof (u32),.format_trace = format_icnpg_trace,.type =
+    VLIB_NODE_TYPE_INTERNAL,.n_errors =
+    ARRAY_LEN (icnpg_error_strings),.error_strings =
+    icnpg_error_strings,.n_next_nodes = ICNPG_N_NEXT,
+    /* edit / add dispositions here */
+    .next_nodes =
+  {
+  [ICNPG_NEXT_LOOKUP] = "ip4-lookup",[ICNPG_NEXT_DROP] = "ip4-drop",}
+,};
+
+/*
+ * End of packet-generator client node
+ */
+
+/*
+ * Beginning of packet-generation server node
+ */
+
+/* Registration struct for a graph node */
+vlib_node_registration_t icn_pg_server_node;
+
+/* Stats, which end up called "error" even though they aren't... */
+#define foreach_icnpg_server_error		\
+_(PROCESSED, "ICN PG Server packets processed")	\
+_(DROPPED, "ICN PG Server packets dropped")
+
+typedef enum
+{
+#define _(sym,str) ICNPG_SERVER_ERROR_##sym,
+  foreach_icnpg_server_error
+#undef _
+    ICNPG_SERVER_N_ERROR,
+} icnpg_server_error_t;
+
+static char *icnpg_server_error_strings[] = {
+#define _(sym,string) string,
+  foreach_icnpg_server_error
+#undef _
+};
+
+/* Next graph nodes, which reference the list in the actual registration
+ * block below
+ */
+typedef enum
+{
+  ICNPG_SERVER_NEXT_LOOKUP,
+  ICNPG_SERVER_NEXT_DROP,
+  ICNPG_SERVER_N_NEXT,
+} icnpg_server_next_t;
+
+/* Trace context struct */
+typedef struct
+{
+  u32 next_index;
+  u32 sw_if_index;
+  u8 pkt_type;
+  u16 msg_type;
+} icnpg_server_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_icnpg_server_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 *);
+  icnpg_server_trace_t *t = va_arg (*args, icnpg_server_trace_t *);
+
+  s =
+    format (s, "ICNPG SERVER: pkt: %d, msg %d, sw_if_index %d, next index %d",
+	    (int) t->pkt_type, (int) t->msg_type, t->sw_if_index,
+	    t->next_index);
+  return (s);
+}
+
+/*
+ * Node function for the icn packet-generator server.
+ */
+static uword
+icnpg_node_server_fn (vlib_main_t * vm,
+		      vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next;
+  icnpg_server_next_t next_index;
+  u32 pkts_processed = 0, pkts_dropped = 0;
+  u32 bi0, bi1;
+  vlib_buffer_t *b0, *b1;
+  u8 pkt_type0 = 0, pkt_type1 = 0;
+  cicn_pkt_hdr_desc_t pkt_hdr_desc0, pkt_hdr_desc1;
+  u16 msg_type0 = 0, msg_type1 = 0;
+  u8 *body0, *body1;
+  u32 len0, len1;
+  udp_header_t *udp0, *udp1;
+  ip4_header_t *ip0, *ip1;
+  uint8_t *name0, *name1;
+  uint32_t namelen0, namelen1;
+  cicn_main_t *sm = &cicn_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 >= 4 && n_left_to_next >= 2)
+	{
+	  u32 next0 = ICNPG_SERVER_NEXT_DROP;
+	  u32 next1 = ICNPG_SERVER_NEXT_DROP;
+	  u32 sw_if_index0, sw_if_index1;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t *p2, *p3;
+
+	    p2 = vlib_get_buffer (vm, from[2]);
+	    p3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (p2, LOAD);
+	    vlib_prefetch_buffer_header (p3, LOAD);
+
+	    CLIB_PREFETCH (p2->data, (2 * CLIB_CACHE_LINE_BYTES), STORE);
+	    CLIB_PREFETCH (p3->data, (2 * CLIB_CACHE_LINE_BYTES), STORE);
+	  }
+
+	  /* speculatively enqueue b0 and b1 to the current next frame */
+	  to_next[0] = bi0 = from[0];
+	  to_next[1] = bi1 = from[1];
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+	  /* We think that the udp code has handed us the payloads,
+	   * so we need to walk back to the IP headers
+	   */
+	  ASSERT (b0->current_data >=
+		  (sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+	  ASSERT (b1->current_data >=
+		  (sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+	  body0 = vlib_buffer_get_current (b0);
+	  len0 = b0->current_length;
+
+	  body1 = vlib_buffer_get_current (b1);
+	  len1 = b1->current_length;
+
+	  /* Check icn packets, locate names */
+	  if (cicn_parse_pkt (body0, len0, &pkt_type0, &msg_type0,
+			      &name0, &namelen0, &pkt_hdr_desc0) == AOK)
+	    {
+
+	      if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_INTEREST) &&
+				(msg_type0 == CICN_MSG_TYPE_INTEREST)))
+		{
+
+		  /* Change message and packet from Interest to Content */
+		  *(body0 + 1) = CICN_PKT_TYPE_CONTENT;
+		  C_PUTINT16 (body0 + 8, CICN_MSG_TYPE_CONTENT);
+
+		  vlib_buffer_t *rb = NULL;
+		  rb = vlib_get_buffer (vm, sm->pgen_svr_buffer_idx);
+
+		  /* Get the packet length */
+		  uint16_t pkt_len;
+		  C_GETINT16 (pkt_len, body0 + 2);
+
+		  /* Figure out how many bytes we can add to the content
+		   *
+		   * Rule of thumb: We want the size of the IP packet
+		   * to be <= 1400 bytes
+		   */
+		  u16 bytes_to_copy = rb->current_length;
+		  if (bytes_to_copy + pkt_len +
+		      sizeof (udp_header_t) + sizeof (ip4_header_t) > 1400)
+		    {
+		      bytes_to_copy = 1400 - pkt_len - sizeof (ip4_header_t) -
+			sizeof (ip4_header_t);
+		    }
+
+		  /* Add content to the data packet */
+		  u32 index = vlib_buffer_add_data (sm->vlib_main,
+						    b0->free_list_index, bi0,
+						    rb->data,
+						    bytes_to_copy);
+
+		  b0 = vlib_get_buffer (vm, index);
+		  body0 = vlib_buffer_get_current (b0);
+
+		  // Update the length of the message
+		  uint16_t msg_len;
+		  C_GETINT16 (msg_len, body0 + 10);
+		  C_PUTINT16 (body0 + 10, msg_len + bytes_to_copy);
+
+		  // Update the length of the packet
+		  C_PUTINT16 (body0 + 2, pkt_len + bytes_to_copy);
+
+		  vlib_buffer_advance (b0, -(sizeof (udp_header_t)));
+		  udp0 = vlib_buffer_get_current (b0);
+		  vlib_buffer_advance (b0, -(sizeof (ip4_header_t)));
+		  ip0 = vlib_buffer_get_current (b0);
+
+		  /* Rewrite and send */
+		  u32 src_addr = ip0->src_address.as_u32;
+		  ip0->src_address.as_u32 = ip0->dst_address.as_u32;
+		  ip0->dst_address.as_u32 = src_addr;
+
+		  udp0->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (sm->vlib_main,
+					   b0) - sizeof (ip4_header_t));
+
+		  ip0->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (sm->vlib_main, b0));
+
+		  ip0->checksum = ip4_header_checksum (ip0);
+
+		  u16 src_port = udp0->src_port;
+		  udp0->src_port = udp0->dst_port;
+		  udp0->dst_port = src_port;
+		  udp0->checksum = 0;
+
+		  next0 = ICNPG_SERVER_NEXT_LOOKUP;
+		}
+	    }
+
+	  if (cicn_parse_pkt (body1, len1, &pkt_type1, &msg_type1,
+			      &name1, &namelen1, &pkt_hdr_desc1) == AOK)
+	    {
+	      if (PREDICT_TRUE ((pkt_type1 == CICN_PKT_TYPE_INTEREST) &&
+				(msg_type1 == CICN_MSG_TYPE_INTEREST)))
+		{
+
+		  /* Change message and packet types from Interest to Content */
+		  *(body1 + 1) = CICN_PKT_TYPE_CONTENT;
+		  C_PUTINT16 (body1 + 8, CICN_MSG_TYPE_CONTENT);
+
+		  vlib_buffer_t *rb = NULL;
+		  rb = vlib_get_buffer (vm, sm->pgen_svr_buffer_idx);
+
+		  /* Get the packet length */
+		  uint16_t pkt_len;
+		  C_GETINT16 (pkt_len, body1 + 2);
+
+		  /* Figure out how many bytes we can add to the content
+		   *
+		   * Rule of thumb: We want the size of the IP packet
+		   * to be <= 1400 bytes
+		   */
+		  u16 bytes_to_copy = rb->current_length;
+		  if (bytes_to_copy + pkt_len +
+		      sizeof (udp_header_t) + sizeof (ip4_header_t) > 1400)
+		    {
+		      bytes_to_copy = 1400 - pkt_len - sizeof (ip4_header_t) -
+			sizeof (ip4_header_t);
+		    }
+
+		  /* Add content to the data packet */
+		  u32 index = vlib_buffer_add_data (sm->vlib_main,
+						    b1->free_list_index, bi1,
+						    rb->data,
+						    bytes_to_copy);
+
+		  b1 = vlib_get_buffer (vm, index);
+		  body1 = vlib_buffer_get_current (b1);
+
+		  // Update the length of the message
+		  uint16_t msg_len;
+		  C_GETINT16 (msg_len, body1 + 10);
+		  C_PUTINT16 (body1 + 10, msg_len + bytes_to_copy);
+
+		  // Update the length of the packet
+		  C_PUTINT16 (body1 + 2, pkt_len + bytes_to_copy);
+
+		  vlib_buffer_advance (b1, -(sizeof (udp_header_t)));
+		  udp1 = vlib_buffer_get_current (b1);
+		  vlib_buffer_advance (b1, -(sizeof (ip4_header_t)));
+		  ip1 = vlib_buffer_get_current (b1);
+
+		  /* Rewrite and send */
+		  u32 src_addr = ip1->src_address.as_u32;
+		  ip1->src_address.as_u32 = ip1->dst_address.as_u32;
+		  ip1->dst_address.as_u32 = src_addr;
+
+		  udp1->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (sm->vlib_main,
+					   b1) - sizeof (ip4_header_t));
+
+		  ip1->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (sm->vlib_main, b1));
+
+		  ip1->checksum = ip4_header_checksum (ip1);
+
+		  u16 src_port = udp1->src_port;
+		  udp1->src_port = udp1->dst_port;
+		  udp1->dst_port = src_port;
+		  udp1->checksum = 0;
+
+		  next1 = ICNPG_SERVER_NEXT_LOOKUP;
+		}
+	    }
+
+	  /* Send pkt to next node */
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
+	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = ~0;
+
+	  pkts_processed += 2;
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
+	    {
+	      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+		{
+		  icnpg_server_trace_t *t =
+		    vlib_add_trace (vm, node, b0, sizeof (*t));
+		  t->pkt_type = pkt_type0;
+		  t->msg_type = msg_type0;
+		  t->sw_if_index = sw_if_index0;
+		  t->next_index = next0;
+		}
+	      if (b1->flags & VLIB_BUFFER_IS_TRACED)
+		{
+		  icnpg_server_trace_t *t =
+		    vlib_add_trace (vm, node, b1, sizeof (*t));
+		  t->pkt_type = pkt_type1;
+		  t->msg_type = msg_type1;
+		  t->sw_if_index = sw_if_index1;
+		  t->next_index = next1;
+		}
+	    }
+
+	  if (next0 == ICNPG_SERVER_NEXT_DROP)
+	    {
+	      pkts_dropped++;
+	    }
+	  if (next1 == ICNPG_SERVER_NEXT_DROP)
+	    {
+	      pkts_dropped++;
+	    }
+
+	  /* verify speculative enqueues, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, bi1, next0, next1);
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 next0 = ICNPG_SERVER_NEXT_DROP;
+	  u32 sw_if_index0;
+
+	  /* 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);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+	  /* We think that the udp code has handed us the payloads,
+	   * so we need to walk back to the IP headers
+	   */
+	  ASSERT (b0->current_data >=
+		  (sizeof (ip4_header_t) + sizeof (udp_header_t)));
+
+	  body0 = vlib_buffer_get_current (b0);
+	  len0 = b0->current_length;
+
+	  /* Check icn packets, locate names */
+	  if (cicn_parse_pkt (body0, len0, &pkt_type0, &msg_type0,
+			      &name0, &namelen0, &pkt_hdr_desc0) == AOK)
+	    {
+
+	      if (PREDICT_TRUE ((pkt_type0 == CICN_PKT_TYPE_INTEREST) &&
+				(msg_type0 == CICN_MSG_TYPE_INTEREST)))
+		{
+
+		  /* Change message and packet types from Interest to Content */
+		  *(body0 + 1) = CICN_PKT_TYPE_CONTENT;
+		  C_PUTINT16 (body0 + 8, CICN_MSG_TYPE_CONTENT);
+
+		  vlib_buffer_t *rb = NULL;
+		  rb = vlib_get_buffer (vm, sm->pgen_svr_buffer_idx);
+
+		  /* Get the packet length */
+		  uint16_t pkt_len;
+		  C_GETINT16 (pkt_len, body0 + 2);
+
+		  /* Figure out how many bytes we can add to the content
+		   *
+		   * Rule of thumb: We want the size of the IP packet
+		   * to be <= 1400 bytes
+		   */
+		  u16 bytes_to_copy = rb->current_length;
+		  if (bytes_to_copy + pkt_len +
+		      sizeof (udp_header_t) + sizeof (ip4_header_t) > 1400)
+		    {
+		      bytes_to_copy = 1400 - pkt_len - sizeof (ip4_header_t) -
+			sizeof (ip4_header_t);
+		    }
+
+		  /* Add content to the data packet */
+		  u32 index = vlib_buffer_add_data (sm->vlib_main,
+						    b0->free_list_index, bi0,
+						    rb->data,
+						    bytes_to_copy);
+
+		  b0 = vlib_get_buffer (vm, index);
+		  body0 = vlib_buffer_get_current (b0);
+
+		  // Update the length of the message
+		  uint16_t msg_len;
+		  C_GETINT16 (msg_len, body0 + 10);
+		  C_PUTINT16 (body0 + 10, msg_len + bytes_to_copy);
+
+		  // Update the length of the packet
+		  C_PUTINT16 (body0 + 2, pkt_len + bytes_to_copy);
+
+		  vlib_buffer_advance (b0, -(sizeof (udp_header_t)));
+		  udp0 = vlib_buffer_get_current (b0);
+		  vlib_buffer_advance (b0, -(sizeof (ip4_header_t)));
+		  ip0 = vlib_buffer_get_current (b0);
+
+		  /* Rewrite and send */
+		  u32 src_addr = ip0->src_address.as_u32;
+		  ip0->src_address.as_u32 = ip0->dst_address.as_u32;
+		  ip0->dst_address.as_u32 = src_addr;
+		  udp0->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (sm->vlib_main,
+					   b0) - sizeof (ip4_header_t));
+
+		  ip0->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (sm->vlib_main, b0));
+
+		  ip0->checksum = ip4_header_checksum (ip0);
+
+		  u16 src_port = udp0->src_port;
+		  udp0->src_port = udp0->dst_port;
+		  udp0->dst_port = src_port;
+		  udp0->checksum = 0;
+
+		  next0 = ICNPG_SERVER_NEXT_LOOKUP;
+		}
+	    }
+
+	  /* Send pkt to ip lookup */
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
+
+	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      icnpg_server_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->pkt_type = pkt_type0;
+	      t->msg_type = msg_type0;
+	      t->sw_if_index = sw_if_index0;
+	      t->next_index = next0;
+	    }
+
+	  pkts_processed += 1;
+
+	  if (next0 == ICNPG_SERVER_NEXT_DROP)
+	    {
+	      pkts_dropped++;
+	    }
+
+	  /* 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, icn_pg_server_node.index,
+			       ICNPG_SERVER_ERROR_PROCESSED, pkts_processed);
+  vlib_node_increment_counter (vm, icn_pg_server_node.index,
+			       ICNPG_SERVER_ERROR_DROPPED, pkts_dropped);
+
+  return (frame->n_vectors);
+}
+
+VLIB_REGISTER_NODE (icn_pg_server_node) =
+{
+  .function = icnpg_node_server_fn,.name = "icnpg-server",.vector_size =
+    sizeof (u32),.format_trace = format_icnpg_server_trace,.type =
+    VLIB_NODE_TYPE_INTERNAL,.n_errors =
+    ARRAY_LEN (icnpg_server_error_strings),.error_strings =
+    icnpg_server_error_strings,.n_next_nodes = ICNPG_SERVER_N_NEXT,
+    /* edit / add dispositions here */
+    .next_nodes =
+  {
+  [ICNPG_SERVER_NEXT_LOOKUP] = "ip4-lookup",
+      [ICNPG_SERVER_NEXT_DROP] = "ip4-drop",}
+,};
+
+/*
+ * End of packet-generator server node
+ */