gre: move to a plugin

Move GRE folder under vnet to the plugin folder, and modify some of path
of the #inlude<header> to the new path.

Add a plugin.c file to register a plugin.

JIRA: VPP-2044

Type: improvement
Change-Id: I7f64cecd97538a7492e56a41558dab58281a9fa5
Signed-off-by: Chuhao Tang <nicotang@cisco.com>

1 files changed, 576 insertions, 0 deletions

diff --git a/src/plugins/gre/node.c b/src/plugins/gre/node.c
new file mode 100644
index 00000000000..7ee22c3cb11
--- /dev/null
+++ b/src/plugins/gre/node.c
@@ -0,0 +1,576 @@
+/*
+ * node.c: gre packet processing
+ *
+ * Copyright (c) 2012 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/pg/pg.h>
+#include <gre/gre.h>
+#include <vnet/mpls/mpls.h>
+#include <vppinfra/sparse_vec.h>
+
+#define foreach_gre_input_next                                                \
+  _ (PUNT, "error-punt")                                                      \
+  _ (DROP, "error-drop")                                                      \
+  _ (ETHERNET_INPUT, "ethernet-input")                                        \
+  _ (IP4_INPUT, "ip4-input")                                                  \
+  _ (IP6_INPUT, "ip6-input")                                                  \
+  _ (MPLS_INPUT, "mpls-input")
+
+typedef enum
+{
+#define _(s, n) GRE_INPUT_NEXT_##s,
+  foreach_gre_input_next
+#undef _
+    GRE_INPUT_N_NEXT,
+} gre_input_next_t;
+
+typedef struct
+{
+  u32 tunnel_id;
+  u32 length;
+  ip46_address_t src;
+  ip46_address_t dst;
+} gre_rx_trace_t;
+
+extern u8 *format_gre_rx_trace (u8 *s, va_list *args);
+
+#ifndef CLIB_MARCH_VARIANT
+u8 *
+format_gre_rx_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 *);
+  gre_rx_trace_t *t = va_arg (*args, gre_rx_trace_t *);
+
+  s = format (s, "GRE: tunnel %d len %d src %U dst %U", t->tunnel_id,
+	      clib_net_to_host_u16 (t->length), format_ip46_address, &t->src,
+	      IP46_TYPE_ANY, format_ip46_address, &t->dst, IP46_TYPE_ANY);
+  return s;
+}
+#endif /* CLIB_MARCH_VARIANT */
+
+typedef struct
+{
+  /* Sparse vector mapping gre protocol in network byte order
+     to next index. */
+  u16 *next_by_protocol;
+} gre_input_runtime_t;
+
+always_inline void
+gre_trace (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_buffer_t *b,
+	   u32 tun_sw_if_index, const ip6_header_t *ip6,
+	   const ip4_header_t *ip4, int is_ipv6)
+{
+  gre_rx_trace_t *tr = vlib_add_trace (vm, node, b, sizeof (*tr));
+  tr->tunnel_id = tun_sw_if_index;
+  if (is_ipv6)
+    {
+      tr->length = ip6->payload_length;
+      tr->src.ip6.as_u64[0] = ip6->src_address.as_u64[0];
+      tr->src.ip6.as_u64[1] = ip6->src_address.as_u64[1];
+      tr->dst.ip6.as_u64[0] = ip6->dst_address.as_u64[0];
+      tr->dst.ip6.as_u64[1] = ip6->dst_address.as_u64[1];
+    }
+  else
+    {
+      tr->length = ip4->length;
+      tr->src.as_u64[0] = tr->src.as_u64[1] = 0;
+      tr->dst.as_u64[0] = tr->dst.as_u64[1] = 0;
+      tr->src.ip4.as_u32 = ip4->src_address.as_u32;
+      tr->dst.ip4.as_u32 = ip4->dst_address.as_u32;
+    }
+}
+
+always_inline void
+gre_tunnel_get (const gre_main_t *gm, vlib_node_runtime_t *node,
+		vlib_buffer_t *b, u16 *next, const gre_tunnel_key_t *key,
+		gre_tunnel_key_t *cached_key, u32 *tun_sw_if_index,
+		u32 *cached_tun_sw_if_index, int is_ipv6)
+{
+  const uword *p;
+  p = is_ipv6 ? hash_get_mem (gm->tunnel_by_key6, &key->gtk_v6) :
+		      hash_get_mem (gm->tunnel_by_key4, &key->gtk_v4);
+  if (PREDICT_FALSE (!p))
+    {
+      *next = GRE_INPUT_NEXT_DROP;
+      b->error = node->errors[GRE_ERROR_NO_SUCH_TUNNEL];
+      *tun_sw_if_index = ~0;
+    }
+  else
+    {
+      const gre_tunnel_t *tun;
+      tun = pool_elt_at_index (gm->tunnels, *p);
+      *cached_tun_sw_if_index = *tun_sw_if_index = tun->sw_if_index;
+      if (is_ipv6)
+	cached_key->gtk_v6 = key->gtk_v6;
+      else
+	cached_key->gtk_v4 = key->gtk_v4;
+    }
+}
+
+always_inline uword
+gre_input (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame,
+	   const int is_ipv6)
+{
+  gre_main_t *gm = &gre_main;
+  u32 *from, n_left_from;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
+  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
+  u16 cached_protocol = ~0;
+  u32 cached_next_index = SPARSE_VEC_INVALID_INDEX;
+  u32 cached_tun_sw_if_index = ~0;
+  gre_tunnel_key_t cached_key;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  vlib_get_buffers (vm, from, bufs, n_left_from);
+
+  if (is_ipv6)
+    clib_memset (&cached_key.gtk_v6, 0xff, sizeof (cached_key.gtk_v6));
+  else
+    clib_memset (&cached_key.gtk_v4, 0xff, sizeof (cached_key.gtk_v4));
+
+  while (n_left_from >= 2)
+    {
+      const ip6_header_t *ip6[2];
+      const ip4_header_t *ip4[2];
+      const gre_header_t *gre[2];
+      u32 nidx[2];
+      next_info_t ni[2];
+      u8 type[2];
+      u16 version[2];
+      u32 len[2];
+      gre_tunnel_key_t key[2];
+      u8 matched[2];
+      u32 tun_sw_if_index[2];
+
+      if (PREDICT_TRUE (n_left_from >= 6))
+	{
+	  vlib_prefetch_buffer_data (b[2], LOAD);
+	  vlib_prefetch_buffer_data (b[3], LOAD);
+	  vlib_prefetch_buffer_header (b[4], STORE);
+	  vlib_prefetch_buffer_header (b[5], STORE);
+	}
+
+      if (is_ipv6)
+	{
+	  /* ip6_local hands us the ip header, not the gre header */
+	  ip6[0] = vlib_buffer_get_current (b[0]);
+	  ip6[1] = vlib_buffer_get_current (b[1]);
+	  gre[0] = (void *) (ip6[0] + 1);
+	  gre[1] = (void *) (ip6[1] + 1);
+	  vlib_buffer_advance (b[0], sizeof (*ip6[0]) + sizeof (*gre[0]));
+	  vlib_buffer_advance (b[1], sizeof (*ip6[0]) + sizeof (*gre[0]));
+	}
+      else
+	{
+	  /* ip4_local hands us the ip header, not the gre header */
+	  ip4[0] = vlib_buffer_get_current (b[0]);
+	  ip4[1] = vlib_buffer_get_current (b[1]);
+	  gre[0] = (void *) (ip4[0] + 1);
+	  gre[1] = (void *) (ip4[1] + 1);
+	  vlib_buffer_advance (b[0], sizeof (*ip4[0]) + sizeof (*gre[0]));
+	  vlib_buffer_advance (b[1], sizeof (*ip4[0]) + sizeof (*gre[0]));
+	}
+
+      if (PREDICT_TRUE (cached_protocol == gre[0]->protocol))
+	{
+	  nidx[0] = cached_next_index;
+	}
+      else
+	{
+	  cached_next_index = nidx[0] =
+	    sparse_vec_index (gm->next_by_protocol, gre[0]->protocol);
+	  cached_protocol = gre[0]->protocol;
+	}
+      if (PREDICT_TRUE (cached_protocol == gre[1]->protocol))
+	{
+	  nidx[1] = cached_next_index;
+	}
+      else
+	{
+	  cached_next_index = nidx[1] =
+	    sparse_vec_index (gm->next_by_protocol, gre[1]->protocol);
+	  cached_protocol = gre[1]->protocol;
+	}
+
+      ni[0] = vec_elt (gm->next_by_protocol, nidx[0]);
+      ni[1] = vec_elt (gm->next_by_protocol, nidx[1]);
+      next[0] = ni[0].next_index;
+      next[1] = ni[1].next_index;
+      type[0] = ni[0].tunnel_type;
+      type[1] = ni[1].tunnel_type;
+
+      b[0]->error = nidx[0] == SPARSE_VEC_INVALID_INDEX ?
+			    node->errors[GRE_ERROR_UNKNOWN_PROTOCOL] :
+			    node->errors[GRE_ERROR_NONE];
+      b[1]->error = nidx[1] == SPARSE_VEC_INVALID_INDEX ?
+			    node->errors[GRE_ERROR_UNKNOWN_PROTOCOL] :
+			    node->errors[GRE_ERROR_NONE];
+
+      version[0] = clib_net_to_host_u16 (gre[0]->flags_and_version);
+      version[1] = clib_net_to_host_u16 (gre[1]->flags_and_version);
+      version[0] &= GRE_VERSION_MASK;
+      version[1] &= GRE_VERSION_MASK;
+
+      b[0]->error =
+	version[0] ? node->errors[GRE_ERROR_UNSUPPORTED_VERSION] : b[0]->error;
+      next[0] = version[0] ? GRE_INPUT_NEXT_DROP : next[0];
+      b[1]->error =
+	version[1] ? node->errors[GRE_ERROR_UNSUPPORTED_VERSION] : b[1]->error;
+      next[1] = version[1] ? GRE_INPUT_NEXT_DROP : next[1];
+
+      len[0] = vlib_buffer_length_in_chain (vm, b[0]);
+      len[1] = vlib_buffer_length_in_chain (vm, b[1]);
+
+      /* always search for P2P types in the DP */
+      if (is_ipv6)
+	{
+	  gre_mk_key6 (&ip6[0]->dst_address, &ip6[0]->src_address,
+		       vnet_buffer (b[0])->ip.fib_index, type[0],
+		       TUNNEL_MODE_P2P, 0, &key[0].gtk_v6);
+	  gre_mk_key6 (&ip6[1]->dst_address, &ip6[1]->src_address,
+		       vnet_buffer (b[1])->ip.fib_index, type[1],
+		       TUNNEL_MODE_P2P, 0, &key[1].gtk_v6);
+	  matched[0] = gre_match_key6 (&cached_key.gtk_v6, &key[0].gtk_v6);
+	  matched[1] = gre_match_key6 (&cached_key.gtk_v6, &key[1].gtk_v6);
+	}
+      else
+	{
+	  gre_mk_key4 (ip4[0]->dst_address, ip4[0]->src_address,
+		       vnet_buffer (b[0])->ip.fib_index, type[0],
+		       TUNNEL_MODE_P2P, 0, &key[0].gtk_v4);
+	  gre_mk_key4 (ip4[1]->dst_address, ip4[1]->src_address,
+		       vnet_buffer (b[1])->ip.fib_index, type[1],
+		       TUNNEL_MODE_P2P, 0, &key[1].gtk_v4);
+	  matched[0] = gre_match_key4 (&cached_key.gtk_v4, &key[0].gtk_v4);
+	  matched[1] = gre_match_key4 (&cached_key.gtk_v4, &key[1].gtk_v4);
+	}
+
+      tun_sw_if_index[0] = cached_tun_sw_if_index;
+      tun_sw_if_index[1] = cached_tun_sw_if_index;
+      if (PREDICT_FALSE (!matched[0]))
+	gre_tunnel_get (gm, node, b[0], &next[0], &key[0], &cached_key,
+			&tun_sw_if_index[0], &cached_tun_sw_if_index, is_ipv6);
+      if (PREDICT_FALSE (!matched[1]))
+	gre_tunnel_get (gm, node, b[1], &next[1], &key[1], &cached_key,
+			&tun_sw_if_index[1], &cached_tun_sw_if_index, is_ipv6);
+
+      if (PREDICT_TRUE (next[0] > GRE_INPUT_NEXT_DROP))
+	{
+	  vlib_increment_combined_counter (
+	    &gm->vnet_main->interface_main
+	       .combined_sw_if_counters[VNET_INTERFACE_COUNTER_RX],
+	    vm->thread_index, tun_sw_if_index[0], 1 /* packets */,
+	    len[0] /* bytes */);
+	  vnet_buffer (b[0])->sw_if_index[VLIB_RX] = tun_sw_if_index[0];
+	}
+      if (PREDICT_TRUE (next[1] > GRE_INPUT_NEXT_DROP))
+	{
+	  vlib_increment_combined_counter (
+	    &gm->vnet_main->interface_main
+	       .combined_sw_if_counters[VNET_INTERFACE_COUNTER_RX],
+	    vm->thread_index, tun_sw_if_index[1], 1 /* packets */,
+	    len[1] /* bytes */);
+	  vnet_buffer (b[1])->sw_if_index[VLIB_RX] = tun_sw_if_index[1];
+	}
+
+      vnet_buffer (b[0])->sw_if_index[VLIB_TX] = (u32) ~0;
+      vnet_buffer (b[1])->sw_if_index[VLIB_TX] = (u32) ~0;
+
+      if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
+	gre_trace (vm, node, b[0], tun_sw_if_index[0], ip6[0], ip4[0],
+		   is_ipv6);
+      if (PREDICT_FALSE (b[1]->flags & VLIB_BUFFER_IS_TRACED))
+	gre_trace (vm, node, b[1], tun_sw_if_index[1], ip6[1], ip4[1],
+		   is_ipv6);
+
+      b += 2;
+      next += 2;
+      n_left_from -= 2;
+    }
+
+  while (n_left_from >= 1)
+    {
+      const ip6_header_t *ip6[1];
+      const ip4_header_t *ip4[1];
+      const gre_header_t *gre[1];
+      u32 nidx[1];
+      next_info_t ni[1];
+      u8 type[1];
+      u16 version[1];
+      u32 len[1];
+      gre_tunnel_key_t key[1];
+      u8 matched[1];
+      u32 tun_sw_if_index[1];
+
+      if (PREDICT_TRUE (n_left_from >= 3))
+	{
+	  vlib_prefetch_buffer_data (b[1], LOAD);
+	  vlib_prefetch_buffer_header (b[2], STORE);
+	}
+
+      if (is_ipv6)
+	{
+	  /* ip6_local hands us the ip header, not the gre header */
+	  ip6[0] = vlib_buffer_get_current (b[0]);
+	  gre[0] = (void *) (ip6[0] + 1);
+	  vlib_buffer_advance (b[0], sizeof (*ip6[0]) + sizeof (*gre[0]));
+	}
+      else
+	{
+	  /* ip4_local hands us the ip header, not the gre header */
+	  ip4[0] = vlib_buffer_get_current (b[0]);
+	  gre[0] = (void *) (ip4[0] + 1);
+	  vlib_buffer_advance (b[0], sizeof (*ip4[0]) + sizeof (*gre[0]));
+	}
+
+      if (PREDICT_TRUE (cached_protocol == gre[0]->protocol))
+	{
+	  nidx[0] = cached_next_index;
+	}
+      else
+	{
+	  cached_next_index = nidx[0] =
+	    sparse_vec_index (gm->next_by_protocol, gre[0]->protocol);
+	  cached_protocol = gre[0]->protocol;
+	}
+
+      ni[0] = vec_elt (gm->next_by_protocol, nidx[0]);
+      next[0] = ni[0].next_index;
+      type[0] = ni[0].tunnel_type;
+
+      b[0]->error = nidx[0] == SPARSE_VEC_INVALID_INDEX ?
+			    node->errors[GRE_ERROR_UNKNOWN_PROTOCOL] :
+			    node->errors[GRE_ERROR_NONE];
+
+      version[0] = clib_net_to_host_u16 (gre[0]->flags_and_version);
+      version[0] &= GRE_VERSION_MASK;
+
+      b[0]->error =
+	version[0] ? node->errors[GRE_ERROR_UNSUPPORTED_VERSION] : b[0]->error;
+      next[0] = version[0] ? GRE_INPUT_NEXT_DROP : next[0];
+
+      len[0] = vlib_buffer_length_in_chain (vm, b[0]);
+
+      if (is_ipv6)
+	{
+	  gre_mk_key6 (&ip6[0]->dst_address, &ip6[0]->src_address,
+		       vnet_buffer (b[0])->ip.fib_index, type[0],
+		       TUNNEL_MODE_P2P, 0, &key[0].gtk_v6);
+	  matched[0] = gre_match_key6 (&cached_key.gtk_v6, &key[0].gtk_v6);
+	}
+      else
+	{
+	  gre_mk_key4 (ip4[0]->dst_address, ip4[0]->src_address,
+		       vnet_buffer (b[0])->ip.fib_index, type[0],
+		       TUNNEL_MODE_P2P, 0, &key[0].gtk_v4);
+	  matched[0] = gre_match_key4 (&cached_key.gtk_v4, &key[0].gtk_v4);
+	}
+
+      tun_sw_if_index[0] = cached_tun_sw_if_index;
+      if (PREDICT_FALSE (!matched[0]))
+	gre_tunnel_get (gm, node, b[0], &next[0], &key[0], &cached_key,
+			&tun_sw_if_index[0], &cached_tun_sw_if_index, is_ipv6);
+
+      if (PREDICT_TRUE (next[0] > GRE_INPUT_NEXT_DROP))
+	{
+	  vlib_increment_combined_counter (
+	    &gm->vnet_main->interface_main
+	       .combined_sw_if_counters[VNET_INTERFACE_COUNTER_RX],
+	    vm->thread_index, tun_sw_if_index[0], 1 /* packets */,
+	    len[0] /* bytes */);
+	  vnet_buffer (b[0])->sw_if_index[VLIB_RX] = tun_sw_if_index[0];
+	}
+
+      vnet_buffer (b[0])->sw_if_index[VLIB_TX] = (u32) ~0;
+
+      if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
+	gre_trace (vm, node, b[0], tun_sw_if_index[0], ip6[0], ip4[0],
+		   is_ipv6);
+
+      b += 1;
+      next += 1;
+      n_left_from -= 1;
+    }
+
+  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
+
+  vlib_node_increment_counter (
+    vm, is_ipv6 ? gre6_input_node.index : gre4_input_node.index,
+    GRE_ERROR_PKTS_DECAP, n_left_from);
+
+  return frame->n_vectors;
+}
+
+VLIB_NODE_FN (gre4_input_node)
+(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
+{
+  return gre_input (vm, node, from_frame, /* is_ip6 */ 0);
+}
+
+VLIB_NODE_FN (gre6_input_node)
+(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
+{
+  return gre_input (vm, node, from_frame, /* is_ip6 */ 1);
+}
+
+static char *gre_error_strings[] = {
+#define gre_error(n, s) s,
+#include "error.def"
+#undef gre_error
+};
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (gre4_input_node) = {
+  .name = "gre4-input",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = GRE_N_ERROR,
+  .error_strings = gre_error_strings,
+
+  .n_next_nodes = GRE_INPUT_N_NEXT,
+  .next_nodes = {
+#define _(s, n) [GRE_INPUT_NEXT_##s] = n,
+    foreach_gre_input_next
+#undef _
+  },
+
+  .format_buffer = format_gre_header_with_length,
+  .format_trace = format_gre_rx_trace,
+  .unformat_buffer = unformat_gre_header,
+};
+
+VLIB_REGISTER_NODE (gre6_input_node) = {
+  .name = "gre6-input",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .runtime_data_bytes = sizeof (gre_input_runtime_t),
+
+  .n_errors = GRE_N_ERROR,
+  .error_strings = gre_error_strings,
+
+  .n_next_nodes = GRE_INPUT_N_NEXT,
+  .next_nodes = {
+#define _(s, n) [GRE_INPUT_NEXT_##s] = n,
+    foreach_gre_input_next
+#undef _
+  },
+
+  .format_buffer = format_gre_header_with_length,
+  .format_trace = format_gre_rx_trace,
+  .unformat_buffer = unformat_gre_header,
+};
+/* *INDENT-ON* */
+
+#ifndef CLIB_MARCH_VARIANT
+void
+gre_register_input_protocol (vlib_main_t *vm, gre_protocol_t protocol,
+			     u32 node_index, gre_tunnel_type_t tunnel_type)
+{
+  gre_main_t *em = &gre_main;
+  gre_protocol_info_t *pi;
+  next_info_t *n;
+  u32 i;
+
+  {
+    clib_error_t *error = vlib_call_init_function (vm, gre_input_init);
+    if (error)
+      clib_error_report (error);
+  }
+
+  pi = gre_get_protocol_info (em, protocol);
+  pi->node_index = node_index;
+  pi->tunnel_type = tunnel_type;
+  pi->next_index = vlib_node_add_next (vm, gre4_input_node.index, node_index);
+  i = vlib_node_add_next (vm, gre6_input_node.index, node_index);
+  ASSERT (i == pi->next_index);
+
+  /* Setup gre protocol -> next index sparse vector mapping. */
+  n = sparse_vec_validate (em->next_by_protocol,
+			   clib_host_to_net_u16 (protocol));
+  n->next_index = pi->next_index;
+  n->tunnel_type = tunnel_type;
+}
+
+static void
+gre_setup_node (vlib_main_t *vm, u32 node_index)
+{
+  vlib_node_t *n = vlib_get_node (vm, node_index);
+  pg_node_t *pn = pg_get_node (node_index);
+
+  n->format_buffer = format_gre_header_with_length;
+  n->unformat_buffer = unformat_gre_header;
+  pn->unformat_edit = unformat_pg_gre_header;
+}
+
+static clib_error_t *
+gre_input_init (vlib_main_t *vm)
+{
+  gre_main_t *gm = &gre_main;
+  vlib_node_t *ethernet_input, *ip4_input, *ip6_input, *mpls_unicast_input;
+
+  {
+    clib_error_t *error;
+    error = vlib_call_init_function (vm, gre_init);
+    if (error)
+      clib_error_report (error);
+  }
+
+  gre_setup_node (vm, gre4_input_node.index);
+  gre_setup_node (vm, gre6_input_node.index);
+
+  gm->next_by_protocol =
+    sparse_vec_new (/* elt bytes */ sizeof (gm->next_by_protocol[0]),
+		    /* bits in index */ BITS (((gre_header_t *) 0)->protocol));
+
+  /* These could be moved to the supported protocol input node defn's */
+  ethernet_input = vlib_get_node_by_name (vm, (u8 *) "ethernet-input");
+  ASSERT (ethernet_input);
+  ip4_input = vlib_get_node_by_name (vm, (u8 *) "ip4-input");
+  ASSERT (ip4_input);
+  ip6_input = vlib_get_node_by_name (vm, (u8 *) "ip6-input");
+  ASSERT (ip6_input);
+  mpls_unicast_input = vlib_get_node_by_name (vm, (u8 *) "mpls-input");
+  ASSERT (mpls_unicast_input);
+
+  gre_register_input_protocol (vm, GRE_PROTOCOL_teb, ethernet_input->index,
+			       GRE_TUNNEL_TYPE_TEB);
+
+  gre_register_input_protocol (vm, GRE_PROTOCOL_ip4, ip4_input->index,
+			       GRE_TUNNEL_TYPE_L3);
+
+  gre_register_input_protocol (vm, GRE_PROTOCOL_ip6, ip6_input->index,
+			       GRE_TUNNEL_TYPE_L3);
+
+  gre_register_input_protocol (vm, GRE_PROTOCOL_mpls_unicast,
+			       mpls_unicast_input->index, GRE_TUNNEL_TYPE_L3);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (gre_input_init);
+
+#endif /* CLIB_MARCH_VARIANT */
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */