src/vnet/ip/icmp4.c - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2015 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 /*
  * ip/icmp4.c: ipv4 icmp
  *
  * Copyright (c) 2008 Eliot Dresselhaus
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sublicense, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */

 #include <vlib/vlib.h>
 #include <vnet/ip/ip.h>
 #include <vnet/pg/pg.h>
 #include <vnet/ip/ip_sas.h>
 #include <vnet/util/throttle.h>

 /** ICMP throttling */
 static throttle_t icmp_throttle;

 static u8 *
 format_ip4_icmp_type_and_code (u8 * s, va_list * args)
 {
   icmp4_type_t type = va_arg (*args, int);
   u8 code = va_arg (*args, int);
   char *t = 0;

 #define _(n,f) case n: t = #f; break;

   switch (type)
     {
       foreach_icmp4_type;

     default:
       break;
     }

 #undef _

   if (!t)
     return format (s, "unknown 0x%x", type);

   s = format (s, "%s", t);

   t = 0;
   switch ((type << 8) | code)
     {
 #define _(a,n,f) case (ICMP4_##a << 8) | (n): t = #f; break;

       foreach_icmp4_code;

 #undef _
     }

   if (t)
     s = format (s, " %s", t);

   return s;
 }

 static u8 *
 format_ip4_icmp_header (u8 * s, va_list * args)
 {
   icmp46_header_t *icmp = va_arg (*args, icmp46_header_t *);
   u32 max_header_bytes = va_arg (*args, u32);

   /* Nothing to do. */
   if (max_header_bytes < sizeof (icmp[0]))
     return format (s, "ICMP header truncated");

   s = format (s, "ICMP %U checksum 0x%x",
 	      format_ip4_icmp_type_and_code, icmp->type, icmp->code,
 	      clib_net_to_host_u16 (icmp->checksum));

   if ((ICMP4_echo_request == icmp->type || ICMP4_echo_reply == icmp->type)
       && sizeof (icmp[0]) + sizeof (u16) < max_header_bytes)
     {
       s = format (s, " id %u", clib_net_to_host_u16 (*(u16 *) (icmp + 1)));
     }

   return s;
 }

 static u8 *
 format_icmp_input_trace (u8 * s, va_list * va)
 {
   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
   CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
   icmp_input_trace_t *t = va_arg (*va, icmp_input_trace_t *);

   s = format (s, "%U",
 	      format_ip4_header, t->packet_data, sizeof (t->packet_data));

   return s;
 }

 typedef enum
 {
   ICMP_INPUT_NEXT_ERROR,
   ICMP_INPUT_N_NEXT,
 } icmp_input_next_t;

 typedef struct
 {
   uword *type_and_code_by_name;

   uword *type_by_name;

   /* Vector dispatch table indexed by [icmp type]. */
   u8 ip4_input_next_index_by_type[256];
 } icmp4_main_t;

 icmp4_main_t icmp4_main;

 static uword
 ip4_icmp_input (vlib_main_t * vm,
 		vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   icmp4_main_t *im = &icmp4_main;
   uword n_packets = frame->n_vectors;
   u32 *from, *to_next;
   u32 n_left_from, n_left_to_next, next;

   from = vlib_frame_vector_args (frame);
   n_left_from = n_packets;
   next = node->cached_next_index;

   if (node->flags & VLIB_NODE_FLAG_TRACE)
     vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
 				   /* stride */ 1,
 				   sizeof (icmp_input_trace_t));

   while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, next, to_next, n_left_to_next);

       while (n_left_from > 0 && n_left_to_next > 0)
 	{
 	  vlib_buffer_t *p0;
 	  ip4_header_t *ip0;
 	  icmp46_header_t *icmp0;
 	  icmp4_type_t type0;
 	  u32 bi0, next0;

 	  if (PREDICT_TRUE (n_left_from > 2))
 	    {
 	      vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
 	      p0 = vlib_get_buffer (vm, from[1]);
 	      ip0 = vlib_buffer_get_current (p0);
 	      clib_prefetch_load (ip0);
 	    }

 	  bi0 = to_next[0] = from[0];

 	  from += 1;
 	  n_left_from -= 1;
 	  to_next += 1;
 	  n_left_to_next -= 1;

 	  p0 = vlib_get_buffer (vm, bi0);
 	  ip0 = vlib_buffer_get_current (p0);
 	  icmp0 = ip4_next_header (ip0);
 	  type0 = icmp0->type;
 	  next0 = im->ip4_input_next_index_by_type[type0];

 	  p0->error = node->errors[ICMP4_ERROR_UNKNOWN_TYPE];

 	  /* Verify speculative enqueue, maybe switch current next frame */
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next, to_next,
 					   n_left_to_next, bi0, next0);
 	}

       vlib_put_next_frame (vm, node, next, n_left_to_next);
     }

   return frame->n_vectors;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip4_icmp_input_node) = {
   .function = ip4_icmp_input,
   .name = "ip4-icmp-input",

   .vector_size = sizeof (u32),

   .format_trace = format_icmp_input_trace,

   .n_errors = ICMP4_N_ERROR,
   .error_counters = icmp4_error_counters,

   .n_next_nodes = 1,
   .next_nodes = {
     [ICMP_INPUT_NEXT_ERROR] = "ip4-punt",
   },
 };
 /* *INDENT-ON* */

 typedef enum
 {
   IP4_ICMP_ERROR_NEXT_DROP,
   IP4_ICMP_ERROR_NEXT_LOOKUP,
   IP4_ICMP_ERROR_N_NEXT,
 } ip4_icmp_error_next_t;

 static u8
 icmp4_icmp_type_to_error (u8 type)
 {
   switch (type)
     {
     case ICMP4_destination_unreachable:
       return ICMP4_ERROR_DEST_UNREACH_SENT;
     case ICMP4_time_exceeded:
       return ICMP4_ERROR_TTL_EXPIRE_SENT;
     case ICMP4_parameter_problem:
       return ICMP4_ERROR_PARAM_PROBLEM_SENT;
     default:
       return ICMP4_ERROR_DROP;
     }
 }

 static uword
 ip4_icmp_error (vlib_main_t * vm,
 		vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   u32 *from, *to_next;
   uword n_left_from, n_left_to_next;
   ip4_icmp_error_next_t next_index;
   u32 thread_index = vm->thread_index;

   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
   next_index = node->cached_next_index;

   u64 seed = throttle_seed (&icmp_throttle, thread_index, vlib_time_now (vm));

   if (node->flags & VLIB_NODE_FLAG_TRACE)
     vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
 				   /* stride */ 1,
 				   sizeof (icmp_input_trace_t));

   while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

       while (n_left_from > 0 && n_left_to_next > 0)
 	{
 	  /*
 	   * Duplicate first buffer and free the original chain.  Keep
 	   * as much of the original packet as possible, within the
 	   * minimum MTU. We chat "a little" here by keeping whatever
 	   * is available in the first buffer.
 	   */

 	  u32 pi0 = ~0;
 	  u32 org_pi0 = from[0];
 	  u32 next0 = IP4_ICMP_ERROR_NEXT_LOOKUP;
 	  u8 error0 = ICMP4_ERROR_NONE;
 	  vlib_buffer_t *p0, *org_p0;
 	  ip4_header_t *ip0, *out_ip0;
 	  icmp46_header_t *icmp0;
 	  u32 sw_if_index0;
 	  ip_csum_t sum;

 	  org_p0 = vlib_get_buffer (vm, org_pi0);
 	  ip0 = vlib_buffer_get_current (org_p0);

 	  /* Rate limit based on the src,dst addresses in the original packet
 	   */
 	  u64 r0 =
 	    (u64) ip0->dst_address.as_u32 << 32 | ip0->src_address.as_u32;

 	  if (throttle_check (&icmp_throttle, thread_index, r0, seed))
 	    {
 	      vlib_error_count (vm, node->node_index, ICMP4_ERROR_DROP, 1);
 	      from += 1;
 	      n_left_from -= 1;
 	      continue;
 	    }

 	  p0 = vlib_buffer_copy_no_chain (vm, org_p0, &pi0);
 	  if (!p0 || pi0 == ~0)	/* Out of buffers */
 	    continue;

 	  /* Speculatively enqueue p0 to the current next frame */
 	  to_next[0] = pi0;
 	  from += 1;
 	  to_next += 1;
 	  n_left_from -= 1;
 	  n_left_to_next -= 1;

 	  sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];

 	  vlib_buffer_copy_trace_flag (vm, p0, pi0);

 	  /* Add IP header and ICMPv4 header including a 4 byte data field */
 	  vlib_buffer_advance (p0,
 			       -sizeof (ip4_header_t) -
 			       sizeof (icmp46_header_t) - 4);

 	  p0->current_length =
 	    p0->current_length > 576 ? 576 : p0->current_length;
 	  out_ip0 = vlib_buffer_get_current (p0);
 	  icmp0 = (icmp46_header_t *) & out_ip0[1];

 	  /* Fill ip header fields */
 	  out_ip0->ip_version_and_header_length = 0x45;
 	  out_ip0->tos = 0;
 	  out_ip0->length = clib_host_to_net_u16 (p0->current_length);
 	  out_ip0->fragment_id = 0;
 	  out_ip0->flags_and_fragment_offset = 0;
 	  out_ip0->ttl = 0xff;
 	  out_ip0->protocol = IP_PROTOCOL_ICMP;
 	  out_ip0->dst_address = ip0->src_address;
 	  /* Prefer a source address from "offending interface" */
 	  if (!ip4_sas_by_sw_if_index (sw_if_index0, &out_ip0->dst_address,
 				       &out_ip0->src_address))
 	    { /* interface has no IP6 address - should not happen */
 	      next0 = IP4_ICMP_ERROR_NEXT_DROP;
 	      error0 = ICMP4_ERROR_DROP;
 	    }

 	  out_ip0->checksum = ip4_header_checksum (out_ip0);

 	  /* Fill icmp header fields */
 	  icmp0->type = vnet_buffer (p0)->ip.icmp.type;
 	  icmp0->code = vnet_buffer (p0)->ip.icmp.code;
 	  *((u32 *) (icmp0 + 1)) =
 	    clib_host_to_net_u32 (vnet_buffer (p0)->ip.icmp.data);
 	  icmp0->checksum = 0;
 	  sum =
 	    ip_incremental_checksum (0, icmp0,
 				     p0->current_length -
 				     sizeof (ip4_header_t));
 	  icmp0->checksum = ~ip_csum_fold (sum);

 	  /* Update error status */
 	  if (error0 == ICMP4_ERROR_NONE)
 	    error0 = icmp4_icmp_type_to_error (icmp0->type);

 	  vlib_error_count (vm, node->node_index, error0, 1);

 	  /* Verify speculative enqueue, maybe switch current next frame */
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next,
 					   pi0, next0);
 	}
       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }

   /*
    * push the original buffers to error-drop, so that
    * they can get the error counters handled, then freed
    */
   vlib_buffer_enqueue_to_single_next (vm, node,
 				      vlib_frame_vector_args (frame),
 				      IP4_ICMP_ERROR_NEXT_DROP,
 				      frame->n_vectors);

   return frame->n_vectors;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip4_icmp_error_node) = {
   .function = ip4_icmp_error,
   .name = "ip4-icmp-error",
   .vector_size = sizeof (u32),

   .n_errors = ICMP4_N_ERROR,
   .error_counters = icmp4_error_counters,

   .n_next_nodes = IP4_ICMP_ERROR_N_NEXT,
   .next_nodes = {
     [IP4_ICMP_ERROR_NEXT_DROP] = "ip4-drop",
     [IP4_ICMP_ERROR_NEXT_LOOKUP] = "ip4-lookup",
   },

   .format_trace = format_icmp_input_trace,
 };
 /* *INDENT-ON* */


 static uword
 unformat_icmp_type_and_code (unformat_input_t * input, va_list * args)
 {
   icmp46_header_t *h = va_arg (*args, icmp46_header_t *);
   icmp4_main_t *cm = &icmp4_main;
   u32 i;

   if (unformat_user (input, unformat_vlib_number_by_name,
 		     cm->type_and_code_by_name, &i))
     {
       h->type = (i >> 8) & 0xff;
       h->code = (i >> 0) & 0xff;
     }
   else if (unformat_user (input, unformat_vlib_number_by_name,
 			  cm->type_by_name, &i))
     {
       h->type = i;
       h->code = 0;
     }
   else
     return 0;

   return 1;
 }

 static void
 icmp4_pg_edit_function (pg_main_t * pg,
 			pg_stream_t * s,
 			pg_edit_group_t * g, u32 * packets, u32 n_packets)
 {
   vlib_main_t *vm = vlib_get_main ();
   u32 ip_offset, icmp_offset;

   icmp_offset = g->start_byte_offset;
   ip_offset = (g - 1)->start_byte_offset;

   while (n_packets >= 1)
     {
       vlib_buffer_t *p0;
       ip4_header_t *ip0;
       icmp46_header_t *icmp0;
       u32 len0;

       p0 = vlib_get_buffer (vm, packets[0]);
       n_packets -= 1;
       packets += 1;

       ASSERT (p0->current_data == 0);
       ip0 = (void *) (p0->data + ip_offset);
       icmp0 = (void *) (p0->data + icmp_offset);

       /* if IP length has been specified, then calculate the length based on buffer */
       if (ip0->length == 0)
 	len0 = vlib_buffer_length_in_chain (vm, p0) - icmp_offset;
       else
 	len0 = clib_net_to_host_u16 (ip0->length) - icmp_offset;

       icmp0->checksum =
 	~ip_csum_fold (ip_incremental_checksum (0, icmp0, len0));
     }
 }

 typedef struct
 {
   pg_edit_t type, code;
   pg_edit_t checksum;
 } pg_icmp46_header_t;

 always_inline void
 pg_icmp_header_init (pg_icmp46_header_t * p)
 {
   /* Initialize fields that are not bit fields in the IP header. */
 #define _(f) pg_edit_init (&p->f, icmp46_header_t, f);
   _(type);
   _(code);
   _(checksum);
 #undef _
 }

 static uword
 unformat_pg_icmp_header (unformat_input_t * input, va_list * args)
 {
   pg_stream_t *s = va_arg (*args, pg_stream_t *);
   pg_icmp46_header_t *p;
   u32 group_index;

   p = pg_create_edit_group (s, sizeof (p[0]), sizeof (icmp46_header_t),
 			    &group_index);
   pg_icmp_header_init (p);

   p->checksum.type = PG_EDIT_UNSPECIFIED;

   {
     icmp46_header_t tmp;

     if (!unformat (input, "ICMP %U", unformat_icmp_type_and_code, &tmp))
       goto error;

     pg_edit_set_fixed (&p->type, tmp.type);
     pg_edit_set_fixed (&p->code, tmp.code);
   }

   /* Parse options. */
   while (1)
     {
       if (unformat (input, "checksum %U",
 		    unformat_pg_edit, unformat_pg_number, &p->checksum))
 	;

       /* Can't parse input: try next protocol level. */
       else
 	break;
     }

   if (!unformat_user (input, unformat_pg_payload, s))
     goto error;

   if (p->checksum.type == PG_EDIT_UNSPECIFIED)
     {
       pg_edit_group_t *g = pg_stream_get_group (s, group_index);
       g->edit_function = icmp4_pg_edit_function;
       g->edit_function_opaque = 0;
     }

   return 1;

 error:
   /* Free up any edits we may have added. */
   pg_free_edit_group (s);
   return 0;
 }

 void
 ip4_icmp_register_type (vlib_main_t * vm, icmp4_type_t type, u32 node_index)
 {
   icmp4_main_t *im = &icmp4_main;
   u32 old_next_index;

   ASSERT ((int) type < ARRAY_LEN (im->ip4_input_next_index_by_type));
   old_next_index = im->ip4_input_next_index_by_type[type];

   im->ip4_input_next_index_by_type[type]
     = vlib_node_add_next (vm, ip4_icmp_input_node.index, node_index);

   if (old_next_index &&
       (old_next_index != im->ip4_input_next_index_by_type[type]))
     clib_warning ("WARNING: changed next_by_type[%d]", (int) type);
 }

 static clib_error_t *
 icmp4_init (vlib_main_t * vm)
 {
   ip_main_t *im = &ip_main;
   ip_protocol_info_t *pi;
   icmp4_main_t *cm = &icmp4_main;
   clib_error_t *error;

   error = vlib_call_init_function (vm, ip_main_init);

   if (error)
     return error;

   pi = ip_get_protocol_info (im, IP_PROTOCOL_ICMP);
   pi->format_header = format_ip4_icmp_header;
   pi->unformat_pg_edit = unformat_pg_icmp_header;

   cm->type_by_name = hash_create_string (0, sizeof (uword));
 #define _(n,t) hash_set_mem (cm->type_by_name, #t, (n));
   foreach_icmp4_type;
 #undef _

   cm->type_and_code_by_name = hash_create_string (0, sizeof (uword));
 #define _(a,n,t) hash_set_mem (cm->type_by_name, #t, (n) | (ICMP4_##a << 8));
   foreach_icmp4_code;
 #undef _

   clib_memset (cm->ip4_input_next_index_by_type,
 	       ICMP_INPUT_NEXT_ERROR,
 	       sizeof (cm->ip4_input_next_index_by_type));

   vlib_thread_main_t *tm = &vlib_thread_main;
   u32 n_vlib_mains = tm->n_vlib_mains;

   throttle_init (&icmp_throttle, n_vlib_mains, 1e-3);

   return 0;
 }

 VLIB_INIT_FUNCTION (icmp4_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* Copyright (c) 2015 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	/*
	* ip/icmp4.c: ipv4 icmp
	*
	* Copyright (c) 2008 Eliot Dresselhaus
	*
	* Permission is hereby granted, free of charge, to any person obtaining
	* a copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sublicense, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be
	* included in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
	* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
	* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/

	#include <vlib/vlib.h>
	#include <vnet/ip/ip.h>
	#include <vnet/pg/pg.h>
	#include <vnet/ip/ip_sas.h>
	#include <vnet/util/throttle.h>

	/** ICMP throttling */
	static throttle_t icmp_throttle;

	static u8 *
	format_ip4_icmp_type_and_code (u8 * s, va_list * args)
	{
	icmp4_type_t type = va_arg (*args, int);
	u8 code = va_arg (*args, int);
	char *t = 0;

	#define _(n,f) case n: t = #f; break;

	switch (type)
	{
	foreach_icmp4_type;

	default:
	break;
	}

	#undef _

	if (!t)
	return format (s, "unknown 0x%x", type);

	s = format (s, "%s", t);

	t = 0;
	switch ((type << 8) \| code)
	{
	#define _(a,n,f) case (ICMP4_##a << 8) \| (n): t = #f; break;

	foreach_icmp4_code;

	#undef _
	}

	if (t)
	s = format (s, " %s", t);

	return s;
	}

	static u8 *
	format_ip4_icmp_header (u8 * s, va_list * args)
	{
	icmp46_header_t icmp = va_arg (args, icmp46_header_t *);
	u32 max_header_bytes = va_arg (*args, u32);

	/* Nothing to do. */
	if (max_header_bytes < sizeof (icmp[0]))
	return format (s, "ICMP header truncated");

	s = format (s, "ICMP %U checksum 0x%x",
	format_ip4_icmp_type_and_code, icmp->type, icmp->code,
	clib_net_to_host_u16 (icmp->checksum));

	if ((ICMP4_echo_request == icmp->type \|\| ICMP4_echo_reply == icmp->type)
	&& sizeof (icmp[0]) + sizeof (u16) < max_header_bytes)
	{
	s = format (s, " id %u", clib_net_to_host_u16 ((u16 ) (icmp + 1)));
	}

	return s;
	}

	static u8 *
	format_icmp_input_trace (u8 * s, va_list * va)
	{
	CLIB_UNUSED (vlib_main_t * vm) = va_arg (va, vlib_main_t );
	CLIB_UNUSED (vlib_node_t * node) = va_arg (va, vlib_node_t );
	icmp_input_trace_t t = va_arg (va, icmp_input_trace_t *);

	s = format (s, "%U",
	format_ip4_header, t->packet_data, sizeof (t->packet_data));

	return s;
	}

	typedef enum
	{
	ICMP_INPUT_NEXT_ERROR,
	ICMP_INPUT_N_NEXT,
	} icmp_input_next_t;

	typedef struct
	{
	uword *type_and_code_by_name;

	uword *type_by_name;

	/* Vector dispatch table indexed by [icmp type]. */
	u8 ip4_input_next_index_by_type[256];
	} icmp4_main_t;

	icmp4_main_t icmp4_main;

	static uword
	ip4_icmp_input (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * frame)
	{
	icmp4_main_t *im = &icmp4_main;
	uword n_packets = frame->n_vectors;
	u32 from, to_next;
	u32 n_left_from, n_left_to_next, next;

	from = vlib_frame_vector_args (frame);
	n_left_from = n_packets;
	next = node->cached_next_index;

	if (node->flags & VLIB_NODE_FLAG_TRACE)
	vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
	/* stride */ 1,
	sizeof (icmp_input_trace_t));

	while (n_left_from > 0)
	{
	vlib_get_next_frame (vm, node, next, to_next, n_left_to_next);

	while (n_left_from > 0 && n_left_to_next > 0)
	{
	vlib_buffer_t *p0;
	ip4_header_t *ip0;
	icmp46_header_t *icmp0;
	icmp4_type_t type0;
	u32 bi0, next0;

	if (PREDICT_TRUE (n_left_from > 2))
	{
	vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
	p0 = vlib_get_buffer (vm, from[1]);
	ip0 = vlib_buffer_get_current (p0);
	clib_prefetch_load (ip0);
	}

	bi0 = to_next[0] = from[0];

	from += 1;
	n_left_from -= 1;
	to_next += 1;
	n_left_to_next -= 1;

	p0 = vlib_get_buffer (vm, bi0);
	ip0 = vlib_buffer_get_current (p0);
	icmp0 = ip4_next_header (ip0);
	type0 = icmp0->type;
	next0 = im->ip4_input_next_index_by_type[type0];

	p0->error = node->errors[ICMP4_ERROR_UNKNOWN_TYPE];

	/* Verify speculative enqueue, maybe switch current next frame */
	vlib_validate_buffer_enqueue_x1 (vm, node, next, to_next,
	n_left_to_next, bi0, next0);
	}

	vlib_put_next_frame (vm, node, next, n_left_to_next);
	}

	return frame->n_vectors;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ip4_icmp_input_node) = {
	.function = ip4_icmp_input,
	.name = "ip4-icmp-input",

	.vector_size = sizeof (u32),

	.format_trace = format_icmp_input_trace,

	.n_errors = ICMP4_N_ERROR,
	.error_counters = icmp4_error_counters,

	.n_next_nodes = 1,
	.next_nodes = {
	[ICMP_INPUT_NEXT_ERROR] = "ip4-punt",
	},
	};
	/* INDENT-ON */

	typedef enum
	{
	IP4_ICMP_ERROR_NEXT_DROP,
	IP4_ICMP_ERROR_NEXT_LOOKUP,
	IP4_ICMP_ERROR_N_NEXT,
	} ip4_icmp_error_next_t;

	static u8
	icmp4_icmp_type_to_error (u8 type)
	{
	switch (type)
	{
	case ICMP4_destination_unreachable:
	return ICMP4_ERROR_DEST_UNREACH_SENT;
	case ICMP4_time_exceeded:
	return ICMP4_ERROR_TTL_EXPIRE_SENT;
	case ICMP4_parameter_problem:
	return ICMP4_ERROR_PARAM_PROBLEM_SENT;
	default:
	return ICMP4_ERROR_DROP;
	}
	}

	static uword
	ip4_icmp_error (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * frame)
	{
	u32 from, to_next;
	uword n_left_from, n_left_to_next;
	ip4_icmp_error_next_t next_index;
	u32 thread_index = vm->thread_index;

	from = vlib_frame_vector_args (frame);
	n_left_from = frame->n_vectors;
	next_index = node->cached_next_index;

	u64 seed = throttle_seed (&icmp_throttle, thread_index, vlib_time_now (vm));

	if (node->flags & VLIB_NODE_FLAG_TRACE)
	vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
	/* stride */ 1,
	sizeof (icmp_input_trace_t));

	while (n_left_from > 0)
	{
	vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

	while (n_left_from > 0 && n_left_to_next > 0)
	{
	/*
	* Duplicate first buffer and free the original chain. Keep
	* as much of the original packet as possible, within the
	* minimum MTU. We chat "a little" here by keeping whatever
	* is available in the first buffer.
	*/

	u32 pi0 = ~0;
	u32 org_pi0 = from[0];
	u32 next0 = IP4_ICMP_ERROR_NEXT_LOOKUP;
	u8 error0 = ICMP4_ERROR_NONE;
	vlib_buffer_t p0, org_p0;
	ip4_header_t ip0, out_ip0;
	icmp46_header_t *icmp0;
	u32 sw_if_index0;
	ip_csum_t sum;

	org_p0 = vlib_get_buffer (vm, org_pi0);
	ip0 = vlib_buffer_get_current (org_p0);

	/* Rate limit based on the src,dst addresses in the original packet
	*/
	u64 r0 =
	(u64) ip0->dst_address.as_u32 << 32 \| ip0->src_address.as_u32;

	if (throttle_check (&icmp_throttle, thread_index, r0, seed))
	{
	vlib_error_count (vm, node->node_index, ICMP4_ERROR_DROP, 1);
	from += 1;
	n_left_from -= 1;
	continue;
	}

	p0 = vlib_buffer_copy_no_chain (vm, org_p0, &pi0);
	if (!p0 \|\| pi0 == ~0) /* Out of buffers */
	continue;

	/* Speculatively enqueue p0 to the current next frame */
	to_next[0] = pi0;
	from += 1;
	to_next += 1;
	n_left_from -= 1;
	n_left_to_next -= 1;

	sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];

	vlib_buffer_copy_trace_flag (vm, p0, pi0);

	/* Add IP header and ICMPv4 header including a 4 byte data field */
	vlib_buffer_advance (p0,
	-sizeof (ip4_header_t) -
	sizeof (icmp46_header_t) - 4);

	p0->current_length =
	p0->current_length > 576 ? 576 : p0->current_length;
	out_ip0 = vlib_buffer_get_current (p0);
	icmp0 = (icmp46_header_t *) & out_ip0[1];

	/* Fill ip header fields */
	out_ip0->ip_version_and_header_length = 0x45;
	out_ip0->tos = 0;
	out_ip0->length = clib_host_to_net_u16 (p0->current_length);
	out_ip0->fragment_id = 0;
	out_ip0->flags_and_fragment_offset = 0;
	out_ip0->ttl = 0xff;
	out_ip0->protocol = IP_PROTOCOL_ICMP;
	out_ip0->dst_address = ip0->src_address;
	/* Prefer a source address from "offending interface" */
	if (!ip4_sas_by_sw_if_index (sw_if_index0, &out_ip0->dst_address,
	&out_ip0->src_address))
	{ /* interface has no IP6 address - should not happen */
	next0 = IP4_ICMP_ERROR_NEXT_DROP;
	error0 = ICMP4_ERROR_DROP;
	}

	out_ip0->checksum = ip4_header_checksum (out_ip0);

	/* Fill icmp header fields */
	icmp0->type = vnet_buffer (p0)->ip.icmp.type;
	icmp0->code = vnet_buffer (p0)->ip.icmp.code;
	((u32 ) (icmp0 + 1)) =
	clib_host_to_net_u32 (vnet_buffer (p0)->ip.icmp.data);
	icmp0->checksum = 0;
	sum =
	ip_incremental_checksum (0, icmp0,
	p0->current_length -
	sizeof (ip4_header_t));
	icmp0->checksum = ~ip_csum_fold (sum);

	/* Update error status */
	if (error0 == ICMP4_ERROR_NONE)
	error0 = icmp4_icmp_type_to_error (icmp0->type);

	vlib_error_count (vm, node->node_index, error0, 1);

	/* Verify speculative enqueue, maybe switch current next frame */
	vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
	to_next, n_left_to_next,
	pi0, next0);
	}
	vlib_put_next_frame (vm, node, next_index, n_left_to_next);
	}

	/*
	* push the original buffers to error-drop, so that
	* they can get the error counters handled, then freed
	*/
	vlib_buffer_enqueue_to_single_next (vm, node,
	vlib_frame_vector_args (frame),
	IP4_ICMP_ERROR_NEXT_DROP,
	frame->n_vectors);

	return frame->n_vectors;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ip4_icmp_error_node) = {
	.function = ip4_icmp_error,
	.name = "ip4-icmp-error",
	.vector_size = sizeof (u32),

	.n_errors = ICMP4_N_ERROR,
	.error_counters = icmp4_error_counters,

	.n_next_nodes = IP4_ICMP_ERROR_N_NEXT,
	.next_nodes = {
	[IP4_ICMP_ERROR_NEXT_DROP] = "ip4-drop",
	[IP4_ICMP_ERROR_NEXT_LOOKUP] = "ip4-lookup",
	},

	.format_trace = format_icmp_input_trace,
	};
	/* INDENT-ON */


	static uword
	unformat_icmp_type_and_code (unformat_input_t * input, va_list * args)
	{
	icmp46_header_t h = va_arg (args, icmp46_header_t *);
	icmp4_main_t *cm = &icmp4_main;
	u32 i;

	if (unformat_user (input, unformat_vlib_number_by_name,
	cm->type_and_code_by_name, &i))
	{
	h->type = (i >> 8) & 0xff;
	h->code = (i >> 0) & 0xff;
	}
	else if (unformat_user (input, unformat_vlib_number_by_name,
	cm->type_by_name, &i))
	{
	h->type = i;
	h->code = 0;
	}
	else
	return 0;

	return 1;
	}

	static void
	icmp4_pg_edit_function (pg_main_t * pg,
	pg_stream_t * s,
	pg_edit_group_t * g, u32 * packets, u32 n_packets)
	{
	vlib_main_t *vm = vlib_get_main ();
	u32 ip_offset, icmp_offset;

	icmp_offset = g->start_byte_offset;
	ip_offset = (g - 1)->start_byte_offset;

	while (n_packets >= 1)
	{
	vlib_buffer_t *p0;
	ip4_header_t *ip0;
	icmp46_header_t *icmp0;
	u32 len0;

	p0 = vlib_get_buffer (vm, packets[0]);
	n_packets -= 1;
	packets += 1;

	ASSERT (p0->current_data == 0);
	ip0 = (void *) (p0->data + ip_offset);
	icmp0 = (void *) (p0->data + icmp_offset);

	/* if IP length has been specified, then calculate the length based on buffer */
	if (ip0->length == 0)
	len0 = vlib_buffer_length_in_chain (vm, p0) - icmp_offset;
	else
	len0 = clib_net_to_host_u16 (ip0->length) - icmp_offset;

	icmp0->checksum =
	~ip_csum_fold (ip_incremental_checksum (0, icmp0, len0));
	}
	}

	typedef struct
	{
	pg_edit_t type, code;
	pg_edit_t checksum;
	} pg_icmp46_header_t;

	always_inline void
	pg_icmp_header_init (pg_icmp46_header_t * p)
	{
	/* Initialize fields that are not bit fields in the IP header. */
	#define _(f) pg_edit_init (&p->f, icmp46_header_t, f);
	_(type);
	_(code);
	_(checksum);
	#undef _
	}

	static uword
	unformat_pg_icmp_header (unformat_input_t * input, va_list * args)
	{
	pg_stream_t s = va_arg (args, pg_stream_t *);
	pg_icmp46_header_t *p;
	u32 group_index;

	p = pg_create_edit_group (s, sizeof (p[0]), sizeof (icmp46_header_t),
	&group_index);
	pg_icmp_header_init (p);

	p->checksum.type = PG_EDIT_UNSPECIFIED;

	{
	icmp46_header_t tmp;

	if (!unformat (input, "ICMP %U", unformat_icmp_type_and_code, &tmp))
	goto error;

	pg_edit_set_fixed (&p->type, tmp.type);
	pg_edit_set_fixed (&p->code, tmp.code);
	}

	/* Parse options. */
	while (1)
	{
	if (unformat (input, "checksum %U",
	unformat_pg_edit, unformat_pg_number, &p->checksum))
	;

	/* Can't parse input: try next protocol level. */
	else
	break;
	}

	if (!unformat_user (input, unformat_pg_payload, s))
	goto error;

	if (p->checksum.type == PG_EDIT_UNSPECIFIED)
	{
	pg_edit_group_t *g = pg_stream_get_group (s, group_index);
	g->edit_function = icmp4_pg_edit_function;
	g->edit_function_opaque = 0;
	}

	return 1;

	error:
	/* Free up any edits we may have added. */
	pg_free_edit_group (s);
	return 0;
	}

	void
	ip4_icmp_register_type (vlib_main_t * vm, icmp4_type_t type, u32 node_index)
	{
	icmp4_main_t *im = &icmp4_main;
	u32 old_next_index;

	ASSERT ((int) type < ARRAY_LEN (im->ip4_input_next_index_by_type));
	old_next_index = im->ip4_input_next_index_by_type[type];

	im->ip4_input_next_index_by_type[type]
	= vlib_node_add_next (vm, ip4_icmp_input_node.index, node_index);

	if (old_next_index &&
	(old_next_index != im->ip4_input_next_index_by_type[type]))
	clib_warning ("WARNING: changed next_by_type[%d]", (int) type);
	}

	static clib_error_t *
	icmp4_init (vlib_main_t * vm)
	{
	ip_main_t *im = &ip_main;
	ip_protocol_info_t *pi;
	icmp4_main_t *cm = &icmp4_main;
	clib_error_t *error;

	error = vlib_call_init_function (vm, ip_main_init);

	if (error)
	return error;

	pi = ip_get_protocol_info (im, IP_PROTOCOL_ICMP);
	pi->format_header = format_ip4_icmp_header;
	pi->unformat_pg_edit = unformat_pg_icmp_header;

	cm->type_by_name = hash_create_string (0, sizeof (uword));
	#define _(n,t) hash_set_mem (cm->type_by_name, #t, (n));
	foreach_icmp4_type;
	#undef _

	cm->type_and_code_by_name = hash_create_string (0, sizeof (uword));
	#define _(a,n,t) hash_set_mem (cm->type_by_name, #t, (n) \| (ICMP4_##a << 8));
	foreach_icmp4_code;
	#undef _

	clib_memset (cm->ip4_input_next_index_by_type,
	ICMP_INPUT_NEXT_ERROR,
	sizeof (cm->ip4_input_next_index_by_type));

	vlib_thread_main_t *tm = &vlib_thread_main;
	u32 n_vlib_mains = tm->n_vlib_mains;

	throttle_init (&icmp_throttle, n_vlib_mains, 1e-3);

	return 0;
	}

	VLIB_INIT_FUNCTION (icmp4_init);

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