src/vnet/ip-neighbor/ip6_neighbor.c - fdio/vpp - Gitiles

 /*
  * ip/ip6_neighbor.c: IP6 neighbor handling
  *
  * Copyright (c) 2010 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/ip-neighbor/ip6_neighbor.h>
 #include <vnet/util/throttle.h>

 /** ND throttling */
 static throttle_t nd_throttle;

 void
 ip6_neighbor_probe_dst (const ip_adjacency_t * adj, const ip6_address_t * dst)
 {
   ip_interface_address_t *ia;
   ip6_address_t *src;

   src = ip6_interface_address_matching_destination
     (&ip6_main, dst, adj->rewrite_header.sw_if_index, &ia);

   if (!src)
     return;

   ip6_neighbor_probe (vlib_get_main (), vnet_get_main (), adj, src, dst);
 }

 void
 ip6_neighbor_advertise (vlib_main_t * vm,
 			vnet_main_t * vnm,
 			u32 sw_if_index, const ip6_address_t * addr)
 {
   vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
   ip6_main_t *i6m = &ip6_main;
   u8 *rewrite, rewrite_len;
   u8 dst_address[6];

   if (NULL == addr)
     addr = ip6_interface_first_address (i6m, sw_if_index);

   if (addr)
     {
       clib_warning
 	("Sending unsolicitated NA IP6 address %U on sw_if_idex %d",
 	 format_ip6_address, addr, sw_if_index);

       /* Form unsolicited neighbor advertisement packet from NS pkt template */
       int bogus_length;
       u32 bi = 0;
       icmp6_neighbor_solicitation_header_t *h =
 	vlib_packet_template_get_packet (vm,
 					 &ip6_neighbor_packet_template,
 					 &bi);
       if (!h)
 	return;

       ip6_set_reserved_multicast_address (&h->ip.dst_address,
 					  IP6_MULTICAST_SCOPE_link_local,
 					  IP6_MULTICAST_GROUP_ID_all_hosts);
       h->ip.src_address = addr[0];
       h->neighbor.icmp.type = ICMP6_neighbor_advertisement;
       h->neighbor.target_address = addr[0];
       h->neighbor.advertisement_flags = clib_host_to_net_u32
 	(ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
       h->link_layer_option.header.type =
 	ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address;
       clib_memcpy (h->link_layer_option.ethernet_address,
 		   hi->hw_address, vec_len (hi->hw_address));
       h->neighbor.icmp.checksum =
 	ip6_tcp_udp_icmp_compute_checksum (vm, 0, &h->ip, &bogus_length);
       ASSERT (bogus_length == 0);

       /* Setup MAC header with IP6 Etype and mcast DMAC */
       vlib_buffer_t *b = vlib_get_buffer (vm, bi);
       ip6_multicast_ethernet_address (dst_address,
 				      IP6_MULTICAST_GROUP_ID_all_hosts);
       rewrite =
 	ethernet_build_rewrite (vnm, sw_if_index, VNET_LINK_IP6, dst_address);
       rewrite_len = vec_len (rewrite);
       vlib_buffer_advance (b, -rewrite_len);
       ethernet_header_t *e = vlib_buffer_get_current (b);
       clib_memcpy (e->dst_address, rewrite, rewrite_len);
       vec_free (rewrite);

       /* Send unsolicited ND advertisement packet out the specified interface */
       vnet_buffer (b)->sw_if_index[VLIB_RX] =
 	vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
       vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
       u32 *to_next = vlib_frame_vector_args (f);
       to_next[0] = bi;
       f->n_vectors = 1;
       vlib_put_frame_to_node (vm, hi->output_node_index, f);
     }
 }

 typedef enum
 {
   IP6_NBR_NEXT_DROP,
   IP6_NBR_NEXT_REPLY_TX,
   IP6_NBR_N_NEXT,
 } ip6_discover_neighbor_next_t;

 typedef enum
 {
   IP6_NBR_ERROR_DROP,
   IP6_NBR_ERROR_REQUEST_SENT,
   IP6_NBR_ERROR_NO_SOURCE_ADDRESS,
   IP6_NBR_ERROR_NO_BUFFERS,
 } ip6_discover_neighbor_error_t;

 static uword
 ip6_discover_neighbor_inline (vlib_main_t * vm,
 			      vlib_node_runtime_t * node,
 			      vlib_frame_t * frame, int is_glean)
 {
   vnet_main_t *vnm = vnet_get_main ();
   u32 *from, *to_next_drop;
   uword n_left_from, n_left_to_next_drop;
   u64 seed;
   u32 thread_index = vm->thread_index;

   if (node->flags & VLIB_NODE_FLAG_TRACE)
     ip6_forward_next_trace (vm, node, frame, VLIB_TX);

   seed = throttle_seed (&nd_throttle, thread_index, vlib_time_now (vm));

   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;

   while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, IP6_NBR_NEXT_DROP,
 			   to_next_drop, n_left_to_next_drop);

       while (n_left_from > 0 && n_left_to_next_drop > 0)
 	{
 	  u32 pi0, adj_index0, sw_if_index0, drop0, r0;
 	  vnet_hw_interface_t *hw_if0;
 	  vlib_buffer_t *p0, *b0;
 	  ip_adjacency_t *adj0;
 	  ip6_address_t src;
 	  ip6_header_t *ip0;

 	  pi0 = from[0];

 	  p0 = vlib_get_buffer (vm, pi0);

 	  adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];

 	  ip0 = vlib_buffer_get_current (p0);

 	  adj0 = adj_get (adj_index0);

 	  if (!is_glean)
 	    {
 	      ip0->dst_address.as_u64[0] =
 		adj0->sub_type.nbr.next_hop.ip6.as_u64[0];
 	      ip0->dst_address.as_u64[1] =
 		adj0->sub_type.nbr.next_hop.ip6.as_u64[1];
 	    }

 	  sw_if_index0 = adj0->rewrite_header.sw_if_index;
 	  vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;

 	  /* combine the address and interface for a hash */
 	  r0 = ip6_address_hash_to_u64 (&ip0->dst_address) ^ sw_if_index0;

 	  drop0 = throttle_check (&nd_throttle, thread_index, r0, seed);

 	  from += 1;
 	  n_left_from -= 1;
 	  to_next_drop[0] = pi0;
 	  to_next_drop += 1;
 	  n_left_to_next_drop -= 1;

 	  hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);

 	  /* If the interface is link-down, drop the pkt */
 	  if (!(hw_if0->flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
 	    drop0 = 1;

 	  if (!ip6_link_is_enabled (sw_if_index0))
 	    drop0 = 1;

 	  /*
 	   * the adj has been updated to a rewrite but the node the DPO that got
 	   * us here hasn't - yet. no big deal. we'll drop while we wait.
 	   */
 	  if (IP_LOOKUP_NEXT_REWRITE == adj0->lookup_next_index)
 	    drop0 = 1;

 	  if (drop0)
 	    {
 	      p0->error = node->errors[IP6_NBR_ERROR_DROP];
 	      continue;
 	    }

 	  /*
 	   * Choose source address based on destination lookup
 	   * adjacency.
 	   */
 	  if (!ip6_src_address_for_packet (sw_if_index0,
 					   &ip0->dst_address, &src))
 	    {
 	      /* There is no address on the interface */
 	      p0->error = node->errors[IP6_NBR_ERROR_NO_SOURCE_ADDRESS];
 	      continue;
 	    }

 	  b0 = ip6_neighbor_probe (vm, vnm, adj0, &src, &ip0->dst_address);

 	  if (PREDICT_TRUE (NULL != b0))
 	    {
 	      clib_memcpy_fast (b0->opaque2, p0->opaque2,
 				sizeof (p0->opaque2));
 	      b0->flags |= p0->flags & VLIB_BUFFER_IS_TRACED;
 	      b0->trace_handle = p0->trace_handle;
 	      p0->error = node->errors[IP6_NBR_ERROR_REQUEST_SENT];
 	    }
 	  else
 	    {
 	      /* There is no address on the interface */
 	      p0->error = node->errors[IP6_NBR_ERROR_NO_BUFFERS];
 	      continue;
 	    }
 	}

       vlib_put_next_frame (vm, node, IP6_NBR_NEXT_DROP, n_left_to_next_drop);
     }

   return frame->n_vectors;
 }

 static uword
 ip6_discover_neighbor (vlib_main_t * vm,
 		       vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   return (ip6_discover_neighbor_inline (vm, node, frame, 0));
 }

 static uword
 ip6_glean (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   return (ip6_discover_neighbor_inline (vm, node, frame, 1));
 }

 static char *ip6_discover_neighbor_error_strings[] = {
   [IP6_NBR_ERROR_DROP] = "address overflow drops",
   [IP6_NBR_ERROR_REQUEST_SENT] = "neighbor solicitations sent",
   [IP6_NBR_ERROR_NO_SOURCE_ADDRESS] = "no source address for ND solicitation",
   [IP6_NBR_ERROR_NO_BUFFERS] = "no buffers",
 };

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip6_glean_node) =
 {
   .function = ip6_glean,
   .name = "ip6-glean",
   .vector_size = sizeof (u32),
   .format_trace = format_ip6_forward_next_trace,
   .n_errors = ARRAY_LEN (ip6_discover_neighbor_error_strings),
   .error_strings = ip6_discover_neighbor_error_strings,
   .n_next_nodes = IP6_NBR_N_NEXT,
   .next_nodes =
   {
     [IP6_NBR_NEXT_DROP] = "ip6-drop",
     [IP6_NBR_NEXT_REPLY_TX] = "ip6-rewrite-mcast",
   },
 };
 VLIB_REGISTER_NODE (ip6_discover_neighbor_node) =
 {
   .function = ip6_discover_neighbor,
   .name = "ip6-discover-neighbor",
   .vector_size = sizeof (u32),
   .format_trace = format_ip6_forward_next_trace,
   .n_errors = ARRAY_LEN (ip6_discover_neighbor_error_strings),
   .error_strings = ip6_discover_neighbor_error_strings,
   .n_next_nodes = IP6_NBR_N_NEXT,
   .next_nodes =
   {
     [IP6_NBR_NEXT_DROP] = "ip6-drop",
     [IP6_NBR_NEXT_REPLY_TX] = "ip6-rewrite-mcast",
   },
 };
 /* *INDENT-ON* */

 /* Template used to generate IP6 neighbor solicitation packets. */
 vlib_packet_template_t ip6_neighbor_packet_template;

 static clib_error_t *
 ip6_neighbor_init (vlib_main_t * vm)
 {
   icmp6_neighbor_solicitation_header_t p;

   clib_memset (&p, 0, sizeof (p));

   p.ip.ip_version_traffic_class_and_flow_label =
     clib_host_to_net_u32 (0x6 << 28);
   p.ip.payload_length =
     clib_host_to_net_u16 (sizeof (p) -
 			  STRUCT_OFFSET_OF
 			  (icmp6_neighbor_solicitation_header_t, neighbor));
   p.ip.protocol = IP_PROTOCOL_ICMP6;
   p.ip.hop_limit = 255;
   ip6_set_solicited_node_multicast_address (&p.ip.dst_address, 0);

   p.neighbor.icmp.type = ICMP6_neighbor_solicitation;

   p.link_layer_option.header.type =
     ICMP6_NEIGHBOR_DISCOVERY_OPTION_source_link_layer_address;
   p.link_layer_option.header.n_data_u64s =
     sizeof (p.link_layer_option) / sizeof (u64);

   vlib_packet_template_init (vm,
 			     &ip6_neighbor_packet_template, &p, sizeof (p),
 			     /* alloc chunk size */ 8,
 			     "ip6 neighbor discovery");

   return NULL;
 }

 VLIB_INIT_FUNCTION (ip6_neighbor_init);

 static clib_error_t *
 ip6_nd_main_loop_enter (vlib_main_t * vm)
 {
   vlib_thread_main_t *tm = &vlib_thread_main;

   throttle_init (&nd_throttle, tm->n_vlib_mains, 1e-3);

   return 0;
 }

 VLIB_MAIN_LOOP_ENTER_FUNCTION (ip6_nd_main_loop_enter);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* ip/ip6_neighbor.c: IP6 neighbor handling
	*
	* Copyright (c) 2010 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/ip-neighbor/ip6_neighbor.h>
	#include <vnet/util/throttle.h>

	/** ND throttling */
	static throttle_t nd_throttle;

	void
	ip6_neighbor_probe_dst (const ip_adjacency_t * adj, const ip6_address_t * dst)
	{
	ip_interface_address_t *ia;
	ip6_address_t *src;

	src = ip6_interface_address_matching_destination
	(&ip6_main, dst, adj->rewrite_header.sw_if_index, &ia);

	if (!src)
	return;

	ip6_neighbor_probe (vlib_get_main (), vnet_get_main (), adj, src, dst);
	}

	void
	ip6_neighbor_advertise (vlib_main_t * vm,
	vnet_main_t * vnm,
	u32 sw_if_index, const ip6_address_t * addr)
	{
	vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
	ip6_main_t *i6m = &ip6_main;
	u8 *rewrite, rewrite_len;
	u8 dst_address[6];

	if (NULL == addr)
	addr = ip6_interface_first_address (i6m, sw_if_index);

	if (addr)
	{
	clib_warning
	("Sending unsolicitated NA IP6 address %U on sw_if_idex %d",
	format_ip6_address, addr, sw_if_index);

	/* Form unsolicited neighbor advertisement packet from NS pkt template */
	int bogus_length;
	u32 bi = 0;
	icmp6_neighbor_solicitation_header_t *h =
	vlib_packet_template_get_packet (vm,
	&ip6_neighbor_packet_template,
	&bi);
	if (!h)
	return;

	ip6_set_reserved_multicast_address (&h->ip.dst_address,
	IP6_MULTICAST_SCOPE_link_local,
	IP6_MULTICAST_GROUP_ID_all_hosts);
	h->ip.src_address = addr[0];
	h->neighbor.icmp.type = ICMP6_neighbor_advertisement;
	h->neighbor.target_address = addr[0];
	h->neighbor.advertisement_flags = clib_host_to_net_u32
	(ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
	h->link_layer_option.header.type =
	ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address;
	clib_memcpy (h->link_layer_option.ethernet_address,
	hi->hw_address, vec_len (hi->hw_address));
	h->neighbor.icmp.checksum =
	ip6_tcp_udp_icmp_compute_checksum (vm, 0, &h->ip, &bogus_length);
	ASSERT (bogus_length == 0);

	/* Setup MAC header with IP6 Etype and mcast DMAC */
	vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	ip6_multicast_ethernet_address (dst_address,
	IP6_MULTICAST_GROUP_ID_all_hosts);
	rewrite =
	ethernet_build_rewrite (vnm, sw_if_index, VNET_LINK_IP6, dst_address);
	rewrite_len = vec_len (rewrite);
	vlib_buffer_advance (b, -rewrite_len);
	ethernet_header_t *e = vlib_buffer_get_current (b);
	clib_memcpy (e->dst_address, rewrite, rewrite_len);
	vec_free (rewrite);

	/* Send unsolicited ND advertisement packet out the specified interface */
	vnet_buffer (b)->sw_if_index[VLIB_RX] =
	vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
	vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
	u32 *to_next = vlib_frame_vector_args (f);
	to_next[0] = bi;
	f->n_vectors = 1;
	vlib_put_frame_to_node (vm, hi->output_node_index, f);
	}
	}

	typedef enum
	{
	IP6_NBR_NEXT_DROP,
	IP6_NBR_NEXT_REPLY_TX,
	IP6_NBR_N_NEXT,
	} ip6_discover_neighbor_next_t;

	typedef enum
	{
	IP6_NBR_ERROR_DROP,
	IP6_NBR_ERROR_REQUEST_SENT,
	IP6_NBR_ERROR_NO_SOURCE_ADDRESS,
	IP6_NBR_ERROR_NO_BUFFERS,
	} ip6_discover_neighbor_error_t;

	static uword
	ip6_discover_neighbor_inline (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * frame, int is_glean)
	{
	vnet_main_t *vnm = vnet_get_main ();
	u32 from, to_next_drop;
	uword n_left_from, n_left_to_next_drop;
	u64 seed;
	u32 thread_index = vm->thread_index;

	if (node->flags & VLIB_NODE_FLAG_TRACE)
	ip6_forward_next_trace (vm, node, frame, VLIB_TX);

	seed = throttle_seed (&nd_throttle, thread_index, vlib_time_now (vm));

	from = vlib_frame_vector_args (frame);
	n_left_from = frame->n_vectors;

	while (n_left_from > 0)
	{
	vlib_get_next_frame (vm, node, IP6_NBR_NEXT_DROP,
	to_next_drop, n_left_to_next_drop);

	while (n_left_from > 0 && n_left_to_next_drop > 0)
	{
	u32 pi0, adj_index0, sw_if_index0, drop0, r0;
	vnet_hw_interface_t *hw_if0;
	vlib_buffer_t p0, b0;
	ip_adjacency_t *adj0;
	ip6_address_t src;
	ip6_header_t *ip0;

	pi0 = from[0];

	p0 = vlib_get_buffer (vm, pi0);

	adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];

	ip0 = vlib_buffer_get_current (p0);

	adj0 = adj_get (adj_index0);

	if (!is_glean)
	{
	ip0->dst_address.as_u64[0] =
	adj0->sub_type.nbr.next_hop.ip6.as_u64[0];
	ip0->dst_address.as_u64[1] =
	adj0->sub_type.nbr.next_hop.ip6.as_u64[1];
	}

	sw_if_index0 = adj0->rewrite_header.sw_if_index;
	vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;

	/* combine the address and interface for a hash */
	r0 = ip6_address_hash_to_u64 (&ip0->dst_address) ^ sw_if_index0;

	drop0 = throttle_check (&nd_throttle, thread_index, r0, seed);

	from += 1;
	n_left_from -= 1;
	to_next_drop[0] = pi0;
	to_next_drop += 1;
	n_left_to_next_drop -= 1;

	hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);

	/* If the interface is link-down, drop the pkt */
	if (!(hw_if0->flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
	drop0 = 1;

	if (!ip6_link_is_enabled (sw_if_index0))
	drop0 = 1;

	/*
	* the adj has been updated to a rewrite but the node the DPO that got
	* us here hasn't - yet. no big deal. we'll drop while we wait.
	*/
	if (IP_LOOKUP_NEXT_REWRITE == adj0->lookup_next_index)
	drop0 = 1;

	if (drop0)
	{
	p0->error = node->errors[IP6_NBR_ERROR_DROP];
	continue;
	}

	/*
	* Choose source address based on destination lookup
	* adjacency.
	*/
	if (!ip6_src_address_for_packet (sw_if_index0,
	&ip0->dst_address, &src))
	{
	/* There is no address on the interface */
	p0->error = node->errors[IP6_NBR_ERROR_NO_SOURCE_ADDRESS];
	continue;
	}

	b0 = ip6_neighbor_probe (vm, vnm, adj0, &src, &ip0->dst_address);

	if (PREDICT_TRUE (NULL != b0))
	{
	clib_memcpy_fast (b0->opaque2, p0->opaque2,
	sizeof (p0->opaque2));
	b0->flags \|= p0->flags & VLIB_BUFFER_IS_TRACED;
	b0->trace_handle = p0->trace_handle;
	p0->error = node->errors[IP6_NBR_ERROR_REQUEST_SENT];
	}
	else
	{
	/* There is no address on the interface */
	p0->error = node->errors[IP6_NBR_ERROR_NO_BUFFERS];
	continue;
	}
	}

	vlib_put_next_frame (vm, node, IP6_NBR_NEXT_DROP, n_left_to_next_drop);
	}

	return frame->n_vectors;
	}

	static uword
	ip6_discover_neighbor (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * frame)
	{
	return (ip6_discover_neighbor_inline (vm, node, frame, 0));
	}

	static uword
	ip6_glean (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
	{
	return (ip6_discover_neighbor_inline (vm, node, frame, 1));
	}

	static char *ip6_discover_neighbor_error_strings[] = {
	[IP6_NBR_ERROR_DROP] = "address overflow drops",
	[IP6_NBR_ERROR_REQUEST_SENT] = "neighbor solicitations sent",
	[IP6_NBR_ERROR_NO_SOURCE_ADDRESS] = "no source address for ND solicitation",
	[IP6_NBR_ERROR_NO_BUFFERS] = "no buffers",
	};

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ip6_glean_node) =
	{
	.function = ip6_glean,
	.name = "ip6-glean",
	.vector_size = sizeof (u32),
	.format_trace = format_ip6_forward_next_trace,
	.n_errors = ARRAY_LEN (ip6_discover_neighbor_error_strings),
	.error_strings = ip6_discover_neighbor_error_strings,
	.n_next_nodes = IP6_NBR_N_NEXT,
	.next_nodes =
	{
	[IP6_NBR_NEXT_DROP] = "ip6-drop",
	[IP6_NBR_NEXT_REPLY_TX] = "ip6-rewrite-mcast",
	},
	};
	VLIB_REGISTER_NODE (ip6_discover_neighbor_node) =
	{
	.function = ip6_discover_neighbor,
	.name = "ip6-discover-neighbor",
	.vector_size = sizeof (u32),
	.format_trace = format_ip6_forward_next_trace,
	.n_errors = ARRAY_LEN (ip6_discover_neighbor_error_strings),
	.error_strings = ip6_discover_neighbor_error_strings,
	.n_next_nodes = IP6_NBR_N_NEXT,
	.next_nodes =
	{
	[IP6_NBR_NEXT_DROP] = "ip6-drop",
	[IP6_NBR_NEXT_REPLY_TX] = "ip6-rewrite-mcast",
	},
	};
	/* INDENT-ON */

	/* Template used to generate IP6 neighbor solicitation packets. */
	vlib_packet_template_t ip6_neighbor_packet_template;

	static clib_error_t *
	ip6_neighbor_init (vlib_main_t * vm)
	{
	icmp6_neighbor_solicitation_header_t p;

	clib_memset (&p, 0, sizeof (p));

	p.ip.ip_version_traffic_class_and_flow_label =
	clib_host_to_net_u32 (0x6 << 28);
	p.ip.payload_length =
	clib_host_to_net_u16 (sizeof (p) -
	STRUCT_OFFSET_OF
	(icmp6_neighbor_solicitation_header_t, neighbor));
	p.ip.protocol = IP_PROTOCOL_ICMP6;
	p.ip.hop_limit = 255;
	ip6_set_solicited_node_multicast_address (&p.ip.dst_address, 0);

	p.neighbor.icmp.type = ICMP6_neighbor_solicitation;

	p.link_layer_option.header.type =
	ICMP6_NEIGHBOR_DISCOVERY_OPTION_source_link_layer_address;
	p.link_layer_option.header.n_data_u64s =
	sizeof (p.link_layer_option) / sizeof (u64);

	vlib_packet_template_init (vm,
	&ip6_neighbor_packet_template, &p, sizeof (p),
	/* alloc chunk size */ 8,
	"ip6 neighbor discovery");

	return NULL;
	}

	VLIB_INIT_FUNCTION (ip6_neighbor_init);

	static clib_error_t *
	ip6_nd_main_loop_enter (vlib_main_t * vm)
	{
	vlib_thread_main_t *tm = &vlib_thread_main;

	throttle_init (&nd_throttle, tm->n_vlib_mains, 1e-3);

	return 0;
	}

	VLIB_MAIN_LOOP_ENTER_FUNCTION (ip6_nd_main_loop_enter);

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/