Changes for supoprting iOAM/ NSH export. Add a separate node for POP only

handling to support iOAM export dynamic node.

Change-Id: I411ee93ea3ec34ed24c18c1ba4b5dc1c9533e483
Signed-off-by: Vengada <venggovi@cisco.com>

8 files changed, 789 insertions, 15 deletions

diff --git a/nsh-plugin/Makefile.am b/nsh-plugin/Makefile.am
index 2da0460..64be6b6 100644
--- a/nsh-plugin/Makefile.am
+++ b/nsh-plugin/Makefile.am
@@ -22,11 +22,15 @@ CPPFLAGS += -DDEBUG -g
 
 lib_LTLIBRARIES = nsh_plugin.la nsh_test_plugin.la
 nsh_plugin_la_SOURCES = nsh/nsh.c  \
+	nsh/nsh_pop.c \
 	vpp-api/nsh.api.h \
 	nsh-md2-ioam/nsh_md2_ioam.c \
 	nsh-md2-ioam/nsh_md2_ioam_trace.c \
 	nsh-md2-ioam/md2_ioam_transit.c \
-	nsh-md2-ioam/nsh_md2_ioam_api.c
+	nsh-md2-ioam/nsh_md2_ioam_api.c \
+	nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export.c \
+	nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export_thread.c \
+	nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_node.c
 
 nsh_plugin_la_LDFLAGS = -module
 
diff --git a/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export.c b/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export.c
new file mode 100644
index 0000000..4860846
--- /dev/null
+++ b/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export.c
@@ -0,0 +1,180 @@
+/*
+ * Copyright (c) 2016 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.
+ */
+/*
+ *------------------------------------------------------------------
+ * nsh_md2_ioam_export.c - ioam export API / debug CLI handling
+ *------------------------------------------------------------------
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/plugin/plugin.h>
+#include <ioam/export-common/ioam_export.h>
+
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vlibsocket/api.h>
+
+#include <nsh/nsh.h>
+#include <nsh-md2-ioam/nsh_md2_ioam.h>
+
+
+ioam_export_main_t nsh_md2_ioam_export_main;
+
+
+extern vlib_node_registration_t nsh_md2_ioam_export_node;
+extern void nsh_md2_set_next_ioam_export_override (uword next);
+/* Action function shared between message handler and debug CLI */
+int
+nsh_md2_ioam_export_enable_disable (ioam_export_main_t * em,
+				      u8 is_disable,
+				      ip4_address_t * collector_address,
+				      ip4_address_t * src_address)
+{
+  vlib_main_t *vm = em->vlib_main;
+  u32 node_index = nsh_md2_ioam_export_node.index;
+  vlib_node_t *nsh_input_node = NULL;
+
+  if (is_disable == 0)
+    {
+      if (em->my_hbh_slot == ~0)
+	{
+	  /* Hook this export node to nsh-input */
+	  nsh_input_node =
+	    vlib_get_node_by_name (vm, (u8 *) "nsh-input");
+	  if (!nsh_input_node)
+	    {
+	      /* node does not exist give up */
+	      return (-1);
+	    }
+	  em->my_hbh_slot =
+	    vlib_node_add_next (vm, nsh_input_node->index,
+				node_index);
+	}
+      if (1 == ioam_export_header_create (em, collector_address, src_address))
+	{
+	  ioam_export_thread_buffer_init (em, vm);
+	  nsh_md2_set_next_ioam_export_override (em->my_hbh_slot);
+	  /* Turn on the export buffer check process */
+	  vlib_process_signal_event (vm, em->export_process_node_index, 1, 0);
+
+	}
+      else
+	{
+	  return (-2);
+	}
+    }
+  else
+    {
+      nsh_md2_set_next_ioam_export_override (0); // VXLAN_GPE_DECAP_IOAM_V4_NEXT_POP
+      ioam_export_header_cleanup (em, collector_address, src_address);
+      ioam_export_thread_buffer_free (em);
+      /* Turn off the export buffer check process */
+      vlib_process_signal_event (vm, em->export_process_node_index, 2, 0);
+
+    }
+
+  return 0;
+}
+
+
+
+static clib_error_t *
+set_nsh_md2_ioam_export_ipfix_command_fn (vlib_main_t * vm,
+					    unformat_input_t * input,
+					    vlib_cli_command_t * cmd)
+{
+  ioam_export_main_t *em = &nsh_md2_ioam_export_main;
+  ip4_address_t collector, src;
+  u8 is_disable = 0;
+
+  collector.as_u32 = 0;
+  src.as_u32 = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "collector %U", unformat_ip4_address, &collector))
+	;
+      else if (unformat (input, "src %U", unformat_ip4_address, &src))
+	;
+      else if (unformat (input, "disable"))
+	is_disable = 1;
+      else
+	break;
+    }
+
+  if (collector.as_u32 == 0)
+    return clib_error_return (0, "collector address required");
+
+  if (src.as_u32 == 0)
+    return clib_error_return (0, "src address required");
+
+  em->ipfix_collector.as_u32 = collector.as_u32;
+  em->src_address.as_u32 = src.as_u32;
+
+  vlib_cli_output (vm, "Collector %U, src address %U",
+		   format_ip4_address, &em->ipfix_collector,
+		   format_ip4_address, &em->src_address);
+
+  /* Turn on the export timer process */
+  // vlib_process_signal_event (vm, flow_report_process_node.index,
+  //1, 0);
+  if (0 !=
+      nsh_md2_ioam_export_enable_disable (em, is_disable, &collector, &src))
+    {
+      return clib_error_return (0, "Unable to set ioam nsh-md2 export");
+    }
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (set_nsh_md2_ioam_ipfix_command, static) =
+{
+.path = "set nsh-md2-ioam export ipfix",
+.short_help = "set nsh-md2-ioam export ipfix collector <ip4-address> src <ip4-address>",
+.function = set_nsh_md2_ioam_export_ipfix_command_fn,
+};
+/* *INDENT-ON* */
+
+
+#define IPFIX_NSH_MD2_IOAM_EXPORT_ID 274 // TODO: Move this to ioam/ioam_export.h
+static clib_error_t *
+nsh_md2_ioam_export_init (vlib_main_t * vm)
+{
+  ioam_export_main_t *em = &nsh_md2_ioam_export_main;
+  clib_error_t *error = 0;
+
+  em->set_id = IPFIX_NSH_MD2_IOAM_EXPORT_ID;
+  em->unix_time_0 = (u32) time (0);	/* Store starting time */
+  em->vlib_time_0 = vlib_time_now (vm);
+
+  em->my_hbh_slot = ~0;
+  em->vlib_main = vm;
+  em->vnet_main = vnet_get_main ();
+  ioam_export_reset_next_node (em);
+
+  return error;
+}
+
+VLIB_INIT_FUNCTION (nsh_md2_ioam_export_init);
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export_thread.c b/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export_thread.c
new file mode 100644
index 0000000..cf6b2e2
--- /dev/null
+++ b/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_export_thread.c
@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+/*
+ * nsh_md2_ioam_export_thread.c
+ */
+#include <vnet/api_errno.h>
+#include <vppinfra/pool.h>
+#include <ioam/export-common/ioam_export.h>
+
+static vlib_node_registration_t nsh_md2_ioam_export_process_node;
+extern ioam_export_main_t nsh_md2_ioam_export_main;
+
+static uword
+nsh_md2_ioam_export_process (vlib_main_t * vm,
+			       vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  return (ioam_export_process_common (&nsh_md2_ioam_export_main,
+				      vm, rt, f,
+				      nsh_md2_ioam_export_process_node.index));
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nsh_md2_ioam_export_process_node, static) =
+{
+ .function = nsh_md2_ioam_export_process,
+ .type = VLIB_NODE_TYPE_PROCESS,
+ .name = "nsh-md2-ioam-export-process",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_node.c b/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_node.c
new file mode 100644
index 0000000..fb76c60
--- /dev/null
+++ b/nsh-plugin/nsh-md2-ioam/export-nsh-md2-ioam/nsh_md2_ioam_node.c
@@ -0,0 +1,155 @@
+/*
+ * 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.
+ */
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+#include <vnet/ip/ip.h>
+#include <nsh/nsh.h>
+#include <nsh/nsh_packet.h>
+#include <ioam/export-common/ioam_export.h>
+
+typedef struct
+{
+  u32 next_index;
+  u32 flow_label;
+} export_trace_t;
+
+extern ioam_export_main_t nsh_md2_ioam_export_main;
+vlib_node_registration_t export_node;
+/* packet trace format function */
+static u8 *
+format_export_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 *);
+  export_trace_t *t = va_arg (*args, export_trace_t *);
+
+  s = format (s, "EXPORT: flow_label %d, next index %d",
+	      t->flow_label, t->next_index);
+  return s;
+}
+
+vlib_node_registration_t nsh_md2_ioam_export_node;
+
+#define foreach_export_error \
+_(RECORDED, "Packets recorded for export")
+
+typedef enum
+{
+#define _(sym,str) EXPORT_ERROR_##sym,
+  foreach_export_error
+#undef _
+    EXPORT_N_ERROR,
+} export_error_t;
+
+static char *export_error_strings[] = {
+#define _(sym,string) string,
+  foreach_export_error
+#undef _
+};
+
+typedef enum
+{
+  EXPORT_NEXT_NSH_MD2_IOAM_INPUT,
+  EXPORT_N_NEXT,
+} export_next_t;
+
+always_inline void
+copy3cachelines (void *dst, const void *src, size_t n)
+{
+
+  u64 *copy_dst, *copy_src;
+  int i;
+  copy_dst = (u64 *) dst;
+  copy_src = (u64 *) src;
+  if (PREDICT_FALSE (n < DEFAULT_EXPORT_SIZE))
+    {
+      for (i = 0; i < n / 64; i++)
+	{
+	  copy_dst[0] = copy_src[0];
+	  copy_dst[1] = copy_src[1];
+	  copy_dst[2] = copy_src[2];
+	  copy_dst[3] = copy_src[3];
+	  copy_dst[4] = copy_src[4];
+	  copy_dst[5] = copy_src[5];
+	  copy_dst[6] = copy_src[6];
+	  copy_dst[7] = copy_src[7];
+	  copy_dst += 8;
+	  copy_src += 8;
+	}
+      return;
+    }
+  for (i = 0; i < 3; i++)
+    {
+      copy_dst[0] = copy_src[0];
+      copy_dst[1] = copy_src[1];
+      copy_dst[2] = copy_src[2];
+      copy_dst[3] = copy_src[3];
+      copy_dst[4] = copy_src[4];
+      copy_dst[5] = copy_src[5];
+      copy_dst[6] = copy_src[6];
+      copy_dst[7] = copy_src[7];
+      copy_dst += 8;
+      copy_src += 8;
+    }
+}
+
+static void
+nsh_md2_ioam_export_fixup_func (vlib_buffer_t * export_buf,
+			     vlib_buffer_t * pak_buf)
+{
+  /* Todo: on implementing analyse */
+}
+
+static uword
+nsh_md2_ioam_export_node_fn (vlib_main_t * vm,
+			  vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  ioam_export_main_t *em = &nsh_md2_ioam_export_main;
+  ioam_export_node_common (em, vm, node, frame, ip4_header_t, length,
+			   ip_version_and_header_length,
+			   EXPORT_NEXT_NSH_MD2_IOAM_INPUT,
+			   nsh_md2_ioam_export_fixup_func);
+  return frame->n_vectors;
+}
+
+/*
+ * Node for iOAM export
+ */
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nsh_md2_ioam_export_node) =
+{
+  .function = nsh_md2_ioam_export_node_fn,
+  .name = "nsh-md2-ioam-export",
+  .vector_size = sizeof (u32),
+  .format_trace = format_export_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (export_error_strings),
+  .error_strings = export_error_strings,
+  .n_next_nodes = EXPORT_N_NEXT,
+    /* edit / add dispositions here */
+    .next_nodes =
+  {[EXPORT_NEXT_NSH_MD2_IOAM_INPUT] = "nsh-pop"},
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/nsh-plugin/nsh/nsh.api b/nsh-plugin/nsh/nsh.api
index ee3f91f..1ef3c7b 100644
--- a/nsh-plugin/nsh/nsh.api
+++ b/nsh-plugin/nsh/nsh.api
@@ -88,6 +88,7 @@ define nsh_add_del_map {
     u32 mapped_nsp_nsi;
     u32 nsh_action;
     u32 sw_if_index;
+    u32 rx_sw_if_index;
     u32 next_node;
 };
 
@@ -114,5 +115,6 @@ define nsh_map_details {
     u32 mapped_nsp_nsi;
     u32 nsh_action;
     u32 sw_if_index;
+    u32 rx_sw_if_index;
     u32 next_node;
 };
diff --git a/nsh-plugin/nsh/nsh.c b/nsh-plugin/nsh/nsh.c
index bfa75fd..c97856c 100644
--- a/nsh-plugin/nsh/nsh.c
+++ b/nsh-plugin/nsh/nsh.c
@@ -234,10 +234,6 @@ nsh_md2_unregister_option (u16 class,
   return (0);
 }
 
-typedef struct {
-   u8 trace_data[256];
-} nsh_input_trace_t;
-
 /* format from network order */
 u8 * format_nsh_header (u8 * s, va_list * args)
 {
@@ -507,6 +503,7 @@ int nsh_add_del_map (nsh_add_del_map_args_t *a, u32 * map_indexp)
       map->mapped_nsp_nsi = a->map.mapped_nsp_nsi;
       map->nsh_action = a->map.nsh_action;
       map->sw_if_index = a->map.sw_if_index;
+      map->rx_sw_if_index = a->map.rx_sw_if_index;
       map->next_node = a->map.next_node;
 
 
@@ -666,6 +663,7 @@ nsh_add_del_map_command_fn (vlib_main_t * vm,
   int nsh_action_set = 0;
   u32 next_node = ~0;
   u32 sw_if_index = ~0; // temporary requirement to get this moved over to NSHSFC
+  u32 rx_sw_if_index = ~0; // temporary requirement to get this moved over to NSHSFC
   nsh_add_del_map_args_t _a, * a = &_a;
   u32 map_index;
   int rv;
@@ -698,7 +696,7 @@ nsh_add_del_map_command_fn (vlib_main_t * vm,
       next_node = NSH_NODE_NEXT_ENCAP_VXLAN4;
     else if (unformat (line_input, "encap-vxlan6-intf %d", &sw_if_index))
       next_node = NSH_NODE_NEXT_ENCAP_VXLAN6;
-    else if (unformat (line_input, "encap-none %d", &sw_if_index))
+    else if (unformat (line_input, "encap-none %d %d", &sw_if_index, &rx_sw_if_index))
       next_node = NSH_NODE_NEXT_DECAP_ETH_INPUT;
     else
       return clib_error_return (0, "parse error: '%U'",
@@ -717,7 +715,7 @@ nsh_add_del_map_command_fn (vlib_main_t * vm,
     return clib_error_return (0, "nsh_action required: swap|push|pop.");
 
   if (next_node == ~0)
-    return clib_error_return (0, "must specific action: [encap-gre-intf <nn> | encap-vxlan-gpe-intf <nn> | encap-lisp-gpe-intf <nn> | encap-none <rx_sw_if_index>]");
+    return clib_error_return (0, "must specific action: [encap-gre-intf <nn> | encap-vxlan-gpe-intf <nn> | encap-lisp-gpe-intf <nn> | encap-none <tx_sw_if_index> <rx_sw_if_index>]");
 
   memset (a, 0, sizeof (*a));
 
@@ -727,6 +725,7 @@ nsh_add_del_map_command_fn (vlib_main_t * vm,
   a->map.mapped_nsp_nsi = (mapped_nsp<< NSH_NSP_SHIFT) | mapped_nsi;
   a->map.nsh_action = nsh_action;
   a->map.sw_if_index = sw_if_index;
+  a->map.rx_sw_if_index = rx_sw_if_index;
   a->map.next_node = next_node;
 
   rv = nsh_add_del_map(a, &map_index);
@@ -793,6 +792,7 @@ static void vl_api_nsh_add_del_map_t_handler
   a->map.mapped_nsp_nsi = ntohl(mp->mapped_nsp_nsi);
   a->map.nsh_action = ntohl(mp->nsh_action);
   a->map.sw_if_index = ntohl(mp->sw_if_index);
+  a->map.rx_sw_if_index = ntohl(mp->rx_sw_if_index);
   a->map.next_node = ntohl(mp->next_node);
 
   rv = nsh_add_del_map (a, &map_index);
@@ -1309,6 +1309,7 @@ static void send_nsh_map_details
     rmp->mapped_nsp_nsi = htonl(t->mapped_nsp_nsi);
     rmp->nsh_action = htonl(t->nsh_action);
     rmp->sw_if_index = htonl(t->sw_if_index);
+    rmp->rx_sw_if_index = htonl(t->rx_sw_if_index);
     rmp->next_node = htonl(t->next_node);
 
     rmp->context = context;
@@ -1540,7 +1541,7 @@ next_tlv_md2:
 always_inline void
 nsh_md2_decap (vlib_buffer_t * b,
                nsh_base_header_t * hdr,
-	       u32 header_len,
+	       u32 *header_len,
 	       u32 * next,
 	       u32 drop_node_val)
 {
@@ -1552,7 +1553,7 @@ nsh_md2_decap (vlib_buffer_t * b,
 
   /* Populate the NSH Header */
   opt0 = (nsh_md2_data_t *)(hdr + 1);
-  limit0 = (nsh_md2_data_t *) ((u8 *) hdr + header_len);
+  limit0 = (nsh_md2_data_t *) ((u8 *) hdr + *header_len);
 
   /* Scan the set of variable metadata, process ones that we understand */
   while (opt0 < limit0)
@@ -1575,6 +1576,8 @@ nsh_md2_decap (vlib_buffer_t * b,
       /* round to 4-byte */
       option_len = ( (opt0->length+3)>>2 ) << 2;
       opt0 = (nsh_md2_data_t *) (((u8 *) opt0) + sizeof (nsh_md2_data_t) + option_len);
+      *next = (nm->decap_v4_next_override) ? (nm->decap_v4_next_override) : (*next);
+      *header_len = (nm->decap_v4_next_override) ? 0 : (*header_len);
     }
 
   return;
@@ -1735,13 +1738,13 @@ nsh_input_map (vlib_main_t * vm,
 	      /* Manipulate MD2 */
               if(PREDICT_FALSE(hdr0->md_type == 2))
         	{
-	          vnet_buffer(b0)->sw_if_index[VLIB_RX] = map0->sw_if_index;
-        	  nsh_md2_decap(b0, hdr0, header_len0, &next0, NSH_NODE_NEXT_DROP);
+        	  nsh_md2_decap(b0, hdr0, &header_len0, &next0, NSH_NODE_NEXT_DROP);
         	  if (PREDICT_FALSE(next0 == NSH_NODE_NEXT_DROP))
         	    {
         	      error0 = NSH_NODE_ERROR_INVALID_OPTIONS;
         	      goto trace0;
         	    }
+	          vnet_buffer(b0)->sw_if_index[VLIB_RX] = map0->rx_sw_if_index;
         	}
 
               /* Pop NSH header */
@@ -1838,13 +1841,13 @@ nsh_input_map (vlib_main_t * vm,
 	      /* Manipulate MD2 */
               if(PREDICT_FALSE(hdr1->md_type == 2))
         	{
-	          vnet_buffer(b1)->sw_if_index[VLIB_RX] = map1->sw_if_index;
-        	  nsh_md2_decap(b1, hdr1, header_len1, &next1, NSH_NODE_NEXT_DROP);
+        	  nsh_md2_decap(b1, hdr1, &header_len1, &next1, NSH_NODE_NEXT_DROP);
         	  if (PREDICT_FALSE(next1 == NSH_NODE_NEXT_DROP))
         	    {
         	      error1 = NSH_NODE_ERROR_INVALID_OPTIONS;
         	      goto trace1;
         	    }
+	          vnet_buffer(b1)->sw_if_index[VLIB_RX] = map0->rx_sw_if_index;
         	}
 
               /* Pop NSH header */
@@ -2024,13 +2027,13 @@ nsh_input_map (vlib_main_t * vm,
 	      /* Manipulate MD2 */
               if(PREDICT_FALSE(hdr0->md_type == 2))
         	{
-	          vnet_buffer(b0)->sw_if_index[VLIB_RX] = map0->sw_if_index;
-        	  nsh_md2_decap(b0, hdr0, header_len0, &next0, NSH_NODE_NEXT_DROP);
+        	  nsh_md2_decap(b0, hdr0, &header_len0, &next0, NSH_NODE_NEXT_DROP);
         	  if (PREDICT_FALSE(next0 == NSH_NODE_NEXT_DROP))
         	    {
         	      error0 = NSH_NODE_ERROR_INVALID_OPTIONS;
         	      goto trace00;
         	    }
+	          vnet_buffer(b0)->sw_if_index[VLIB_RX] = map0->rx_sw_if_index;
         	}
 
               /* Pop NSH header */
@@ -2282,6 +2285,15 @@ VLIB_REGISTER_NODE (nsh_aware_vnf_proxy_node) = {
 
 VLIB_NODE_FUNCTION_MULTIARCH (nsh_aware_vnf_proxy_node, nsh_aware_vnf_proxy);
 
+void
+nsh_md2_set_next_ioam_export_override (uword next)
+{
+  nsh_main_t *hm = &nsh_main;
+  hm->decap_v4_next_override = next;
+  return;
+}
+
+
 clib_error_t *nsh_init (vlib_main_t *vm)
 {
   nsh_main_t *nm = &nsh_main;
diff --git a/nsh-plugin/nsh/nsh.h b/nsh-plugin/nsh/nsh.h
index 501f756..b03c8e7 100644
--- a/nsh-plugin/nsh/nsh.h
+++ b/nsh-plugin/nsh/nsh.h
@@ -74,6 +74,7 @@ typedef struct {
 
   /* encap if index */
   u32 sw_if_index;
+  u32 rx_sw_if_index;
   u32 next_node;
 } nsh_map_t;
 
@@ -145,6 +146,7 @@ typedef struct {
   int (*pop_options[MAX_MD2_OPTIONS]) (vlib_buffer_t * b,
 				       nsh_tlv_header_t * opt);
   u8 *(*trace[MAX_MD2_OPTIONS]) (u8 * s, nsh_tlv_header_t * opt);
+  uword decap_v4_next_override;
 
   /* convenience */
   vlib_main_t * vlib_main;
@@ -154,6 +156,9 @@ typedef struct {
 nsh_main_t nsh_main;
 
 extern vlib_node_registration_t nsh_aware_vnf_proxy_node;
+typedef struct {
+   u8 trace_data[256];
+} nsh_input_trace_t;
 
 u8 * format_nsh_input_map_trace (u8 * s, va_list * args);
 u8 * format_nsh_header_with_length (u8 * s, va_list * args);
diff --git a/nsh-plugin/nsh/nsh_pop.c b/nsh-plugin/nsh/nsh_pop.c
new file mode 100644
index 0000000..ed3d84a
--- /dev/null
+++ b/nsh-plugin/nsh/nsh_pop.c
@@ -0,0 +1,366 @@
+/*
+ * nsh_pop.c - nsh POP only processing
+ *
+ * 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.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/plugin/plugin.h>
+#include <nsh/nsh.h>
+#include <vnet/gre/gre.h>
+#include <vnet/vxlan/vxlan.h>
+#include <vnet/vxlan-gpe/vxlan_gpe.h>
+#include <vnet/l2/l2_classify.h>
+
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vlibsocket/api.h>
+
+extern nsh_option_map_t * nsh_md2_lookup_option (u16 class, u8 type);
+
+extern u8 * format_nsh_header (u8 * s, va_list * args);
+extern u8 * format_nsh_node_map_trace (u8 * s, va_list * args);
+
+/* format from network order */
+u8 * format_nsh_pop_header (u8 * s, va_list * args)
+{
+  return format_nsh_header(s, args);
+}
+
+
+
+u8 * format_nsh_pop_node_map_trace (u8 * s, va_list * args)
+{
+  return format_nsh_node_map_trace(s, args);
+}
+
+
+static uword
+nsh_pop_inline (vlib_main_t * vm,
+               vlib_node_runtime_t * node,
+               vlib_frame_t * from_frame)
+{
+  u32 n_left_from, next_index, *from, *to_next;
+  nsh_main_t * nm = &nsh_main;
+
+  from = vlib_frame_vector_args(from_frame);
+  n_left_from = 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 bi0, bi1;
+	  vlib_buffer_t * b0, *b1;
+	  u32 next0 = NSH_NODE_NEXT_DROP, next1 = NSH_NODE_NEXT_DROP;
+	  uword * entry0, *entry1;
+	  nsh_base_header_t * hdr0 = 0, *hdr1 = 0;
+	  u32 header_len0 = 0, header_len1 = 0;
+	  u32 nsp_nsi0, nsp_nsi1;
+	  u32 error0, error1;
+	  nsh_map_t * map0 = 0, *map1 = 0;
+
+	  /* 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, LOAD);
+	    CLIB_PREFETCH(p3->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
+	  }
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  from += 2;
+	  to_next += 2;
+	  n_left_from -= 2;
+	  n_left_to_next -= 2;
+
+	  error0 = 0;
+	  error1 = 0;
+
+	  b0 = vlib_get_buffer(vm, bi0);
+	  b1 = vlib_get_buffer(vm, bi1);
+	  hdr0 = vlib_buffer_get_current(b0);
+          nsp_nsi0 = hdr0->nsp_nsi;
+          header_len0 = hdr0->length * 4;
+
+          hdr1 = vlib_buffer_get_current(b1);
+	  nsp_nsi1 = hdr1->nsp_nsi;
+	  header_len1 = hdr1->length * 4;
+
+	  /* Process packet 0 */
+	  entry0 = hash_get_mem(nm->nsh_mapping_by_key, &nsp_nsi0);
+	  if (PREDICT_FALSE(entry0 == 0))
+	    {
+	      error0 = NSH_NODE_ERROR_NO_MAPPING;
+	      goto trace0;
+	    }
+
+	  /* Entry should point to a mapping ...*/
+	  map0 = pool_elt_at_index(nm->nsh_mappings, entry0[0]);
+	  if (PREDICT_FALSE(map0 == 0))
+	    {
+	      error0 = NSH_NODE_ERROR_NO_MAPPING;
+	      goto trace0;
+	    }
+
+	  /* set up things for next node to transmit ie which node to handle it and where */
+	  next0 = map0->next_node;
+	  //vnet_buffer(b0)->sw_if_index[VLIB_TX] = map0->sw_if_index;
+
+	  if(PREDICT_FALSE(map0->nsh_action == NSH_ACTION_POP))
+	    {
+	      /* Manipulate MD2 */
+              if(PREDICT_FALSE(hdr0->md_type == 2))
+        	{
+        	  if (PREDICT_FALSE(next0 == NSH_NODE_NEXT_DROP))
+        	    {
+        	      error0 = NSH_NODE_ERROR_INVALID_OPTIONS;
+        	      goto trace0;
+        	    }
+	          //vnet_buffer(b0)->sw_if_index[VLIB_RX] = map0->sw_if_index;
+        	}
+
+              /* Pop NSH header */
+	      vlib_buffer_advance(b0, (word)header_len0);
+	      goto trace0;
+	    }
+
+	  entry0 = hash_get_mem(nm->nsh_entry_by_key, &map0->mapped_nsp_nsi);
+	  if (PREDICT_FALSE(entry0 == 0))
+	    {
+	      error0 = NSH_NODE_ERROR_NO_ENTRY;
+	      goto trace0;
+	    }
+
+        trace0: b0->error = error0 ? node->errors[error0] : 0;
+
+          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+            {
+              nsh_input_trace_t *tr = vlib_add_trace(vm, node, b0, sizeof(*tr));
+              clib_memcpy ( &(tr->trace_data), hdr0, (hdr0->length*4) );
+            }
+
+	  /* Process packet 1 */
+	  entry1 = hash_get_mem(nm->nsh_mapping_by_key, &nsp_nsi1);
+	  if (PREDICT_FALSE(entry1 == 0))
+	    {
+	      error1 = NSH_NODE_ERROR_NO_MAPPING;
+	      goto trace1;
+	    }
+
+	  /* Entry should point to a mapping ...*/
+	  map1 = pool_elt_at_index(nm->nsh_mappings, entry1[0]);
+	  if (PREDICT_FALSE(map1 == 0))
+	    {
+	      error1 = NSH_NODE_ERROR_NO_MAPPING;
+	      goto trace1;
+	    }
+
+	  /* set up things for next node to transmit ie which node to handle it and where */
+	  next1 = map1->next_node;
+	  //vnet_buffer(b1)->sw_if_index[VLIB_TX] = map1->sw_if_index;
+
+	  if(PREDICT_FALSE(map1->nsh_action == NSH_ACTION_POP))
+	    {
+	      /* Manipulate MD2 */
+              if(PREDICT_FALSE(hdr1->md_type == 2))
+        	{
+        	  if (PREDICT_FALSE(next1 == NSH_NODE_NEXT_DROP))
+        	    {
+        	      error1 = NSH_NODE_ERROR_INVALID_OPTIONS;
+        	      goto trace1;
+        	    }
+	          //vnet_buffer(b1)->sw_if_index[VLIB_RX] = map1->sw_if_index;
+        	}
+
+              /* Pop NSH header */
+	      vlib_buffer_advance(b1, (word)header_len1);
+	      goto trace1;
+	    }
+
+	  entry1 = hash_get_mem(nm->nsh_entry_by_key, &map1->mapped_nsp_nsi);
+	  if (PREDICT_FALSE(entry1 == 0))
+	    {
+	      error1 = NSH_NODE_ERROR_NO_ENTRY;
+	      goto trace1;
+	    }
+
+
+	trace1: b1->error = error1 ? node->errors[error1] : 0;
+
+	  if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      nsh_input_trace_t *tr = vlib_add_trace(vm, node, b1, sizeof(*tr));
+	      clib_memcpy ( &(tr->trace_data), hdr1, (hdr1->length*4) );
+	    }
+
+	  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 bi0 = 0;
+	  vlib_buffer_t * b0 = NULL;
+	  u32 next0 = NSH_NODE_NEXT_DROP;
+	  uword * entry0;
+	  nsh_base_header_t * hdr0 = 0;
+	  u32 header_len0 = 0;
+	  u32 nsp_nsi0;
+	  u32 error0;
+	  nsh_map_t * map0 = 0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+	  error0 = 0;
+
+	  b0 = vlib_get_buffer(vm, bi0);
+	  hdr0 = vlib_buffer_get_current(b0);
+
+          nsp_nsi0 = hdr0->nsp_nsi;
+          header_len0 = hdr0->length * 4;
+
+	  entry0 = hash_get_mem(nm->nsh_mapping_by_key, &nsp_nsi0);
+
+	  if (PREDICT_FALSE(entry0 == 0))
+	    {
+	      error0 = NSH_NODE_ERROR_NO_MAPPING;
+	      goto trace00;
+	    }
+
+	  /* Entry should point to a mapping ...*/
+	  map0 = pool_elt_at_index(nm->nsh_mappings, entry0[0]);
+
+	  if (PREDICT_FALSE(map0 == 0))
+	    {
+	      error0 = NSH_NODE_ERROR_NO_MAPPING;
+	      goto trace00;
+	    }
+
+	  /* set up things for next node to transmit ie which node to handle it and where */
+	  next0 = map0->next_node;
+	  //vnet_buffer(b0)->sw_if_index[VLIB_TX] = map0->sw_if_index;
+
+	  if(PREDICT_FALSE(map0->nsh_action == NSH_ACTION_POP))
+	    {
+	      /* Manipulate MD2 */
+              if(PREDICT_FALSE(hdr0->md_type == 2))
+        	{
+        	  if (PREDICT_FALSE(next0 == NSH_NODE_NEXT_DROP))
+        	    {
+        	      error0 = NSH_NODE_ERROR_INVALID_OPTIONS;
+        	      goto trace00;
+        	    }
+	          //vnet_buffer(b0)->sw_if_index[VLIB_RX] = map0->sw_if_index;
+        	}
+
+              /* Pop NSH header */
+	      vlib_buffer_advance(b0, (word)header_len0);
+	      goto trace00;
+	    }
+
+	  entry0 = hash_get_mem(nm->nsh_entry_by_key, &map0->mapped_nsp_nsi);
+	  if (PREDICT_FALSE(entry0 == 0))
+	    {
+	      error0 = NSH_NODE_ERROR_NO_ENTRY;
+	      goto trace00;
+	    }
+
+	  trace00: b0->error = error0 ? node->errors[error0] : 0;
+
+	  if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      nsh_input_trace_t *tr = vlib_add_trace(vm, node, b0, sizeof(*tr));
+	      clib_memcpy ( &(tr->trace_data[0]), hdr0, (hdr0->length*4) );
+	    }
+
+	  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 from_frame->n_vectors;
+}
+
+/**
+ * @brief Graph processing dispatch function for NSH Input
+ *
+ * @node nsh_input
+ * @param *vm
+ * @param *node
+ * @param *from_frame
+ *
+ * @return from_frame->n_vectors
+ *
+ */
+static uword
+nsh_pop (vlib_main_t * vm, vlib_node_runtime_t * node,
+                  vlib_frame_t * from_frame)
+{
+  return nsh_pop_inline (vm, node, from_frame);
+}
+
+static char * nsh_pop_node_error_strings[] = {
+#define _(sym,string) string,
+  foreach_nsh_node_error
+#undef _
+};
+
+/* register nsh-input node */
+VLIB_REGISTER_NODE (nsh_pop_node) = {
+  .function = nsh_pop,
+  .name = "nsh-pop",
+  .vector_size = sizeof (u32),
+  .format_trace = format_nsh_pop_node_map_trace,
+  .format_buffer = format_nsh_pop_header,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(nsh_pop_node_error_strings),
+  .error_strings = nsh_pop_node_error_strings,
+
+  .n_next_nodes = NSH_NODE_N_NEXT,
+
+  .next_nodes = {
+#define _(s,n) [NSH_NODE_NEXT_##s] = n,
+    foreach_nsh_node_next
+#undef _
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (nsh_pop_node, nsh_pop);
+
+