src/vnet/ip/ip4.h - 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/ip4.h: ip4 main include file
  *
  * 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.
  */

 #ifndef included_ip_ip4_h
 #define included_ip_ip4_h

 #include <vnet/ip/ip4_packet.h>
 #include <vnet/ip/lookup.h>
 #include <vnet/buffer.h>
 #include <vnet/feature/feature.h>
 #include <vnet/ip/icmp46_packet.h>
 #include <vnet/util/throttle.h>

 typedef struct ip4_mfib_t
 {
   /* Hash table for each prefix length mapping. */
   uword *fib_entry_by_dst_address[65];

   /* Table ID (hash key) for this FIB. */
   u32 table_id;

   /* Index into FIB vector. */
   u32 index;
 } ip4_mfib_t;

 struct ip4_main_t;

 typedef void (ip4_add_del_interface_address_function_t)
   (struct ip4_main_t * im,
    uword opaque,
    u32 sw_if_index,
    ip4_address_t * address,
    u32 address_length, u32 if_address_index, u32 is_del);

 typedef struct
 {
   ip4_add_del_interface_address_function_t *function;
   uword function_opaque;
 } ip4_add_del_interface_address_callback_t;

 typedef void (ip4_enable_disable_interface_function_t)
   (struct ip4_main_t * im, uword opaque, u32 sw_if_index, u32 is_enable);

 typedef struct
 {
   ip4_enable_disable_interface_function_t *function;
   uword function_opaque;
 } ip4_enable_disable_interface_callback_t;

 typedef void (ip4_table_bind_function_t)
   (struct ip4_main_t * im,
    uword opaque, u32 sw_if_index, u32 new_fib_index, u32 old_fib_index);

 typedef struct
 {
   ip4_table_bind_function_t *function;
   uword function_opaque;
 } ip4_table_bind_callback_t;

 /**
  * @brief IPv4 main type.
  *
  * State of IPv4 VPP processing including:
  * - FIBs
  * - Feature indices used in feature topological sort
  * - Feature node run time references
  */

 typedef struct ip4_main_t
 {
   ip_lookup_main_t lookup_main;

   /** Vector of FIBs. */
   struct fib_table_t_ *fibs;

   /** Vector of MTries. */
   struct ip4_fib_t_ *v4_fibs;

   /** Vector of MFIBs. */
   struct mfib_table_t_ *mfibs;

   u32 fib_masks[33];

   /** Table index indexed by software interface. */
   u32 *fib_index_by_sw_if_index;

   /** Table index indexed by software interface. */
   u32 *mfib_index_by_sw_if_index;

   /* IP4 enabled count by software interface */
   u8 *ip_enabled_by_sw_if_index;

   /** Hash table mapping table id to fib index.
      ID space is not necessarily dense; index space is dense. */
   uword *fib_index_by_table_id;

   /** Hash table mapping table id to multicast fib index.
      ID space is not necessarily dense; index space is dense. */
   uword *mfib_index_by_table_id;

   /** Functions to call when interface address changes. */
     ip4_add_del_interface_address_callback_t
     * add_del_interface_address_callbacks;

   /** Functions to call when interface becomes IPv4 enabled/disable. */
     ip4_enable_disable_interface_callback_t
     * enable_disable_interface_callbacks;

   /** Functions to call when interface to table biding changes. */
   ip4_table_bind_callback_t *table_bind_callbacks;

   /** Template used to generate IP4 ARP packets. */
   vlib_packet_template_t ip4_arp_request_packet_template;

   /** Seed for Jenkins hash used to compute ip4 flow hash. */
   u32 flow_hash_seed;

   /** @brief Template information for VPP generated packets */
   struct
   {
     /** TTL to use for host generated packets. */
     u8 ttl;

     /** TOS byte to use for host generated packets. */
     u8 tos;

     u8 pad[2];
   } host_config;

   /** Heapsize for the Mtries */
   uword mtrie_heap_size;

   /** The memory heap for the mtries */
   void *mtrie_mheap;

   /** ARP throttling */
   throttle_t arp_throttle;

 } ip4_main_t;

 #define ARP_THROTTLE_BITS	(512)

 /** Global ip4 main structure. */
 extern ip4_main_t ip4_main;
 extern char *ip4_error_strings[];

 /** Global ip4 input node.  Errors get attached to ip4 input node. */
 extern vlib_node_registration_t ip4_input_node;
 extern vlib_node_registration_t ip4_lookup_node;
 extern vlib_node_registration_t ip4_local_node;
 extern vlib_node_registration_t ip4_rewrite_node;
 extern vlib_node_registration_t ip4_rewrite_mcast_node;
 extern vlib_node_registration_t ip4_rewrite_local_node;
 extern vlib_node_registration_t ip4_arp_node;
 extern vlib_node_registration_t ip4_glean_node;
 extern vlib_node_registration_t ip4_midchain_node;
 extern vlib_node_registration_t ip4_punt_node;

 always_inline uword
 ip4_destination_matches_route (const ip4_main_t * im,
 			       const ip4_address_t * key,
 			       const ip4_address_t * dest, uword dest_length)
 {
   return 0 == ((key->data_u32 ^ dest->data_u32) & im->fib_masks[dest_length]);
 }

 always_inline uword
 ip4_destination_matches_interface (ip4_main_t * im,
 				   ip4_address_t * key,
 				   ip_interface_address_t * ia)
 {
   ip4_address_t *a = ip_interface_address_get_address (&im->lookup_main, ia);
   return ip4_destination_matches_route (im, key, a, ia->address_length);
 }

 always_inline int
 ip4_src_address_for_packet (ip_lookup_main_t * lm,
 			    u32 sw_if_index, ip4_address_t * src)
 {
   u32 if_add_index = lm->if_address_pool_index_by_sw_if_index[sw_if_index];
   if (PREDICT_TRUE (if_add_index != ~0))
     {
       ip_interface_address_t *if_add =
 	pool_elt_at_index (lm->if_address_pool, if_add_index);
       ip4_address_t *if_ip = ip_interface_address_get_address (lm, if_add);
       *src = *if_ip;
       return 0;
     }
   else
     {
       src->as_u32 = 0;
     }
   return (!0);
 }

 /* Find interface address which matches destination. */
 always_inline ip4_address_t *
 ip4_interface_address_matching_destination (ip4_main_t * im,
 					    const ip4_address_t * dst,
 					    u32 sw_if_index,
 					    ip_interface_address_t **
 					    result_ia)
 {
   ip_lookup_main_t *lm = &im->lookup_main;
   ip_interface_address_t *ia;
   ip4_address_t *result = 0;

   /* *INDENT-OFF* */
   foreach_ip_interface_address (lm, ia, sw_if_index,
                                 1 /* honor unnumbered */,
   ({
     ip4_address_t * a = ip_interface_address_get_address (lm, ia);
     if (ip4_destination_matches_route (im, dst, a, ia->address_length))
       {
 	result = a;
 	break;
       }
   }));
   /* *INDENT-ON* */
   if (result_ia)
     *result_ia = result ? ia : 0;
   return result;
 }

 ip4_address_t *ip4_interface_first_address (ip4_main_t * im, u32 sw_if_index,
 					    ip_interface_address_t **
 					    result_ia);

 clib_error_t *ip4_add_del_interface_address (vlib_main_t * vm,
 					     u32 sw_if_index,
 					     ip4_address_t * address,
 					     u32 address_length, u32 is_del);

 void ip4_directed_broadcast (u32 sw_if_index, u8 enable);

 void ip4_sw_interface_enable_disable (u32 sw_if_index, u32 is_enable);

 int ip4_address_compare (ip4_address_t * a1, ip4_address_t * a2);

 uword
 ip4_udp_register_listener (vlib_main_t * vm,
 			   u16 dst_port, u32 next_node_index);

 u16 ip4_tcp_udp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
 				  ip4_header_t * ip0);

 void ip4_register_protocol (u32 protocol, u32 node_index);
 void ip4_unregister_protocol (u32 protocolx);

 serialize_function_t serialize_vnet_ip4_main, unserialize_vnet_ip4_main;

 int vnet_set_ip4_flow_hash (u32 table_id,
 			    flow_hash_config_t flow_hash_config);

 int vnet_set_ip4_classify_intfc (vlib_main_t * vm, u32 sw_if_index,
 				 u32 table_index);

 void ip4_punt_policer_add_del (u8 is_add, u32 policer_index);

 void ip4_punt_redirect_add (u32 rx_sw_if_index,
 			    u32 tx_sw_if_index, ip46_address_t * nh);
 void ip4_punt_redirect_add_paths (u32 rx_sw_if_index,
 				  fib_route_path_t * paths);

 void ip4_punt_redirect_del (u32 rx_sw_if_index);

 /* Compute flow hash.  We'll use it to select which adjacency to use for this
    flow.  And other things. */
 always_inline u32
 ip4_compute_flow_hash (const ip4_header_t * ip,
 		       flow_hash_config_t flow_hash_config)
 {
   tcp_header_t *tcp = (void *) (ip + 1);
   u32 a, b, c, t1, t2;
   uword is_tcp_udp = (ip->protocol == IP_PROTOCOL_TCP
 		      || ip->protocol == IP_PROTOCOL_UDP);

   t1 = (flow_hash_config & IP_FLOW_HASH_SRC_ADDR)
     ? ip->src_address.data_u32 : 0;
   t2 = (flow_hash_config & IP_FLOW_HASH_DST_ADDR)
     ? ip->dst_address.data_u32 : 0;

   a = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t2 : t1;
   b = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t1 : t2;

   t1 = is_tcp_udp ? tcp->src : 0;
   t2 = is_tcp_udp ? tcp->dst : 0;

   t1 = (flow_hash_config & IP_FLOW_HASH_SRC_PORT) ? t1 : 0;
   t2 = (flow_hash_config & IP_FLOW_HASH_DST_PORT) ? t2 : 0;

   if (flow_hash_config & IP_FLOW_HASH_SYMMETRIC)
     {
       if (b < a)
 	{
 	  c = a;
 	  a = b;
 	  b = c;
 	}
       if (t2 < t1)
 	{
 	  t2 += t1;
 	  t1 = t2 - t1;
 	  t2 = t2 - t1;
 	}
     }

   b ^= (flow_hash_config & IP_FLOW_HASH_PROTO) ? ip->protocol : 0;
   c = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ?
     (t1 << 16) | t2 : (t2 << 16) | t1;

   hash_v3_mix32 (a, b, c);
   hash_v3_finalize32 (a, b, c);

   return c;
 }

 void
 ip4_forward_next_trace (vlib_main_t * vm,
 			vlib_node_runtime_t * node,
 			vlib_frame_t * frame,
 			vlib_rx_or_tx_t which_adj_index);

 u8 *format_ip4_forward_next_trace (u8 * s, va_list * args);

 u32 ip4_tcp_udp_validate_checksum (vlib_main_t * vm, vlib_buffer_t * p0);

 #define IP_DF 0x4000		/* don't fragment */

 always_inline void *
 vlib_buffer_push_ip4_custom (vlib_main_t * vm, vlib_buffer_t * b,
 			     ip4_address_t * src, ip4_address_t * dst,
 			     int proto, u8 csum_offload, u8 is_df)
 {
   ip4_header_t *ih;

   /* make some room */
   ih = vlib_buffer_push_uninit (b, sizeof (ip4_header_t));

   ih->ip_version_and_header_length = 0x45;
   ih->tos = 0;
   ih->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));

   /* No fragments */
   ih->flags_and_fragment_offset = is_df ? clib_host_to_net_u16 (IP_DF) : 0;
   ih->ttl = 255;
   ih->protocol = proto;
   ih->src_address.as_u32 = src->as_u32;
   ih->dst_address.as_u32 = dst->as_u32;

   vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data;
   b->flags |= VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L3_HDR_OFFSET_VALID;

   /* Offload ip4 header checksum generation */
   if (csum_offload)
     {
       ih->checksum = 0;
       b->flags |= VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
     }
   else
     ih->checksum = ip4_header_checksum (ih);

   return ih;
 }

 /**
  * Push IPv4 header to buffer
  *
  * This does not support fragmentation.
  *
  * @param vm - vlib_main
  * @param b - buffer to write the header to
  * @param src - source IP
  * @param dst - destination IP
  * @param prot - payload proto
  *
  * @return - pointer to start of IP header
  */
 always_inline void *
 vlib_buffer_push_ip4 (vlib_main_t * vm, vlib_buffer_t * b,
 		      ip4_address_t * src, ip4_address_t * dst, int proto,
 		      u8 csum_offload)
 {
   return vlib_buffer_push_ip4_custom (vm, b, src, dst, proto, csum_offload,
 				      1 /* is_df */ );
 }

 always_inline u32
 vlib_buffer_get_ip4_fib_index (vlib_buffer_t * b)
 {
   u32 fib_index, sw_if_index;
   sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
   fib_index = vnet_buffer (b)->sw_if_index[VLIB_TX];
   return (fib_index == (u32) ~ 0) ?
     vec_elt (ip4_main.fib_index_by_sw_if_index, sw_if_index) : fib_index;
 }
 #endif /* included_ip_ip4_h */

 /*
  * 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/ip4.h: ip4 main include file
	*
	* 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.
	*/

	#ifndef included_ip_ip4_h
	#define included_ip_ip4_h

	#include <vnet/ip/ip4_packet.h>
	#include <vnet/ip/lookup.h>
	#include <vnet/buffer.h>
	#include <vnet/feature/feature.h>
	#include <vnet/ip/icmp46_packet.h>
	#include <vnet/util/throttle.h>

	typedef struct ip4_mfib_t
	{
	/* Hash table for each prefix length mapping. */
	uword *fib_entry_by_dst_address[65];

	/* Table ID (hash key) for this FIB. */
	u32 table_id;

	/* Index into FIB vector. */
	u32 index;
	} ip4_mfib_t;

	struct ip4_main_t;

	typedef void (ip4_add_del_interface_address_function_t)
	(struct ip4_main_t * im,
	uword opaque,
	u32 sw_if_index,
	ip4_address_t * address,
	u32 address_length, u32 if_address_index, u32 is_del);

	typedef struct
	{
	ip4_add_del_interface_address_function_t *function;
	uword function_opaque;
	} ip4_add_del_interface_address_callback_t;

	typedef void (ip4_enable_disable_interface_function_t)
	(struct ip4_main_t * im, uword opaque, u32 sw_if_index, u32 is_enable);

	typedef struct
	{
	ip4_enable_disable_interface_function_t *function;
	uword function_opaque;
	} ip4_enable_disable_interface_callback_t;

	typedef void (ip4_table_bind_function_t)
	(struct ip4_main_t * im,
	uword opaque, u32 sw_if_index, u32 new_fib_index, u32 old_fib_index);

	typedef struct
	{
	ip4_table_bind_function_t *function;
	uword function_opaque;
	} ip4_table_bind_callback_t;

	/**
	* @brief IPv4 main type.
	*
	* State of IPv4 VPP processing including:
	* - FIBs
	* - Feature indices used in feature topological sort
	* - Feature node run time references
	*/

	typedef struct ip4_main_t
	{
	ip_lookup_main_t lookup_main;

	/** Vector of FIBs. */
	struct fib_table_t_ *fibs;

	/** Vector of MTries. */
	struct ip4_fib_t_ *v4_fibs;

	/** Vector of MFIBs. */
	struct mfib_table_t_ *mfibs;

	u32 fib_masks[33];

	/** Table index indexed by software interface. */
	u32 *fib_index_by_sw_if_index;

	/** Table index indexed by software interface. */
	u32 *mfib_index_by_sw_if_index;

	/* IP4 enabled count by software interface */
	u8 *ip_enabled_by_sw_if_index;

	/** Hash table mapping table id to fib index.
	ID space is not necessarily dense; index space is dense. */
	uword *fib_index_by_table_id;

	/** Hash table mapping table id to multicast fib index.
	ID space is not necessarily dense; index space is dense. */
	uword *mfib_index_by_table_id;

	/** Functions to call when interface address changes. */
	ip4_add_del_interface_address_callback_t
	* add_del_interface_address_callbacks;

	/** Functions to call when interface becomes IPv4 enabled/disable. */
	ip4_enable_disable_interface_callback_t
	* enable_disable_interface_callbacks;

	/** Functions to call when interface to table biding changes. */
	ip4_table_bind_callback_t *table_bind_callbacks;

	/** Template used to generate IP4 ARP packets. */
	vlib_packet_template_t ip4_arp_request_packet_template;

	/** Seed for Jenkins hash used to compute ip4 flow hash. */
	u32 flow_hash_seed;

	/** @brief Template information for VPP generated packets */
	struct
	{
	/** TTL to use for host generated packets. */
	u8 ttl;

	/** TOS byte to use for host generated packets. */
	u8 tos;

	u8 pad[2];
	} host_config;

	/** Heapsize for the Mtries */
	uword mtrie_heap_size;

	/** The memory heap for the mtries */
	void *mtrie_mheap;

	/** ARP throttling */
	throttle_t arp_throttle;

	} ip4_main_t;

	#define ARP_THROTTLE_BITS (512)

	/** Global ip4 main structure. */
	extern ip4_main_t ip4_main;
	extern char *ip4_error_strings[];

	/** Global ip4 input node. Errors get attached to ip4 input node. */
	extern vlib_node_registration_t ip4_input_node;
	extern vlib_node_registration_t ip4_lookup_node;
	extern vlib_node_registration_t ip4_local_node;
	extern vlib_node_registration_t ip4_rewrite_node;
	extern vlib_node_registration_t ip4_rewrite_mcast_node;
	extern vlib_node_registration_t ip4_rewrite_local_node;
	extern vlib_node_registration_t ip4_arp_node;
	extern vlib_node_registration_t ip4_glean_node;
	extern vlib_node_registration_t ip4_midchain_node;
	extern vlib_node_registration_t ip4_punt_node;

	always_inline uword
	ip4_destination_matches_route (const ip4_main_t * im,
	const ip4_address_t * key,
	const ip4_address_t * dest, uword dest_length)
	{
	return 0 == ((key->data_u32 ^ dest->data_u32) & im->fib_masks[dest_length]);
	}

	always_inline uword
	ip4_destination_matches_interface (ip4_main_t * im,
	ip4_address_t * key,
	ip_interface_address_t * ia)
	{
	ip4_address_t *a = ip_interface_address_get_address (&im->lookup_main, ia);
	return ip4_destination_matches_route (im, key, a, ia->address_length);
	}

	always_inline int
	ip4_src_address_for_packet (ip_lookup_main_t * lm,
	u32 sw_if_index, ip4_address_t * src)
	{
	u32 if_add_index = lm->if_address_pool_index_by_sw_if_index[sw_if_index];
	if (PREDICT_TRUE (if_add_index != ~0))
	{
	ip_interface_address_t *if_add =
	pool_elt_at_index (lm->if_address_pool, if_add_index);
	ip4_address_t *if_ip = ip_interface_address_get_address (lm, if_add);
	src = if_ip;
	return 0;
	}
	else
	{
	src->as_u32 = 0;
	}
	return (!0);
	}

	/* Find interface address which matches destination. */
	always_inline ip4_address_t *
	ip4_interface_address_matching_destination (ip4_main_t * im,
	const ip4_address_t * dst,
	u32 sw_if_index,
	ip_interface_address_t **
	result_ia)
	{
	ip_lookup_main_t *lm = &im->lookup_main;
	ip_interface_address_t *ia;
	ip4_address_t *result = 0;

	/* INDENT-OFF */
	foreach_ip_interface_address (lm, ia, sw_if_index,
	1 /* honor unnumbered */,
	({
	ip4_address_t * a = ip_interface_address_get_address (lm, ia);
	if (ip4_destination_matches_route (im, dst, a, ia->address_length))
	{
	result = a;
	break;
	}
	}));
	/* INDENT-ON */
	if (result_ia)
	*result_ia = result ? ia : 0;
	return result;
	}

	ip4_address_t ip4_interface_first_address (ip4_main_t im, u32 sw_if_index,
	ip_interface_address_t **
	result_ia);

	clib_error_t ip4_add_del_interface_address (vlib_main_t vm,
	u32 sw_if_index,
	ip4_address_t * address,
	u32 address_length, u32 is_del);

	void ip4_directed_broadcast (u32 sw_if_index, u8 enable);

	void ip4_sw_interface_enable_disable (u32 sw_if_index, u32 is_enable);

	int ip4_address_compare (ip4_address_t * a1, ip4_address_t * a2);

	uword
	ip4_udp_register_listener (vlib_main_t * vm,
	u16 dst_port, u32 next_node_index);

	u16 ip4_tcp_udp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
	ip4_header_t * ip0);

	void ip4_register_protocol (u32 protocol, u32 node_index);
	void ip4_unregister_protocol (u32 protocolx);

	serialize_function_t serialize_vnet_ip4_main, unserialize_vnet_ip4_main;

	int vnet_set_ip4_flow_hash (u32 table_id,
	flow_hash_config_t flow_hash_config);

	int vnet_set_ip4_classify_intfc (vlib_main_t * vm, u32 sw_if_index,
	u32 table_index);

	void ip4_punt_policer_add_del (u8 is_add, u32 policer_index);

	void ip4_punt_redirect_add (u32 rx_sw_if_index,
	u32 tx_sw_if_index, ip46_address_t * nh);
	void ip4_punt_redirect_add_paths (u32 rx_sw_if_index,
	fib_route_path_t * paths);

	void ip4_punt_redirect_del (u32 rx_sw_if_index);

	/* Compute flow hash. We'll use it to select which adjacency to use for this
	flow. And other things. */
	always_inline u32
	ip4_compute_flow_hash (const ip4_header_t * ip,
	flow_hash_config_t flow_hash_config)
	{
	tcp_header_t tcp = (void ) (ip + 1);
	u32 a, b, c, t1, t2;
	uword is_tcp_udp = (ip->protocol == IP_PROTOCOL_TCP
	\|\| ip->protocol == IP_PROTOCOL_UDP);

	t1 = (flow_hash_config & IP_FLOW_HASH_SRC_ADDR)
	? ip->src_address.data_u32 : 0;
	t2 = (flow_hash_config & IP_FLOW_HASH_DST_ADDR)
	? ip->dst_address.data_u32 : 0;

	a = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t2 : t1;
	b = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t1 : t2;

	t1 = is_tcp_udp ? tcp->src : 0;
	t2 = is_tcp_udp ? tcp->dst : 0;

	t1 = (flow_hash_config & IP_FLOW_HASH_SRC_PORT) ? t1 : 0;
	t2 = (flow_hash_config & IP_FLOW_HASH_DST_PORT) ? t2 : 0;

	if (flow_hash_config & IP_FLOW_HASH_SYMMETRIC)
	{
	if (b < a)
	{
	c = a;
	a = b;
	b = c;
	}
	if (t2 < t1)
	{
	t2 += t1;
	t1 = t2 - t1;
	t2 = t2 - t1;
	}
	}

	b ^= (flow_hash_config & IP_FLOW_HASH_PROTO) ? ip->protocol : 0;
	c = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ?
	(t1 << 16) \| t2 : (t2 << 16) \| t1;

	hash_v3_mix32 (a, b, c);
	hash_v3_finalize32 (a, b, c);

	return c;
	}

	void
	ip4_forward_next_trace (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * frame,
	vlib_rx_or_tx_t which_adj_index);

	u8 format_ip4_forward_next_trace (u8 s, va_list * args);

	u32 ip4_tcp_udp_validate_checksum (vlib_main_t * vm, vlib_buffer_t * p0);

	#define IP_DF 0x4000 /* don't fragment */

	always_inline void *
	vlib_buffer_push_ip4_custom (vlib_main_t * vm, vlib_buffer_t * b,
	ip4_address_t * src, ip4_address_t * dst,
	int proto, u8 csum_offload, u8 is_df)
	{
	ip4_header_t *ih;

	/* make some room */
	ih = vlib_buffer_push_uninit (b, sizeof (ip4_header_t));

	ih->ip_version_and_header_length = 0x45;
	ih->tos = 0;
	ih->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));

	/* No fragments */
	ih->flags_and_fragment_offset = is_df ? clib_host_to_net_u16 (IP_DF) : 0;
	ih->ttl = 255;
	ih->protocol = proto;
	ih->src_address.as_u32 = src->as_u32;
	ih->dst_address.as_u32 = dst->as_u32;

	vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data;
	b->flags \|= VNET_BUFFER_F_IS_IP4 \| VNET_BUFFER_F_L3_HDR_OFFSET_VALID;

	/* Offload ip4 header checksum generation */
	if (csum_offload)
	{
	ih->checksum = 0;
	b->flags \|= VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
	}
	else
	ih->checksum = ip4_header_checksum (ih);

	return ih;
	}

	/**
	* Push IPv4 header to buffer
	*
	* This does not support fragmentation.
	*
	* @param vm - vlib_main
	* @param b - buffer to write the header to
	* @param src - source IP
	* @param dst - destination IP
	* @param prot - payload proto
	*
	* @return - pointer to start of IP header
	*/
	always_inline void *
	vlib_buffer_push_ip4 (vlib_main_t * vm, vlib_buffer_t * b,
	ip4_address_t * src, ip4_address_t * dst, int proto,
	u8 csum_offload)
	{
	return vlib_buffer_push_ip4_custom (vm, b, src, dst, proto, csum_offload,
	1 /* is_df */ );
	}

	always_inline u32
	vlib_buffer_get_ip4_fib_index (vlib_buffer_t * b)
	{
	u32 fib_index, sw_if_index;
	sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
	fib_index = vnet_buffer (b)->sw_if_index[VLIB_TX];
	return (fib_index == (u32) ~ 0) ?
	vec_elt (ip4_main.fib_index_by_sw_if_index, sw_if_index) : fib_index;
	}
	#endif /* included_ip_ip4_h */

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