vnet/vnet/ip/lookup.h

   1 /*
   2  * Copyright (c) 2015 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 /*
  16  * ip/ip_lookup.h: ip (4 or 6) lookup structures, adjacencies, ...
  17  *
  18  * Copyright (c) 2008 Eliot Dresselhaus
  19  *
  20  * Permission is hereby granted, free of charge, to any person obtaining
  21  * a copy of this software and associated documentation files (the
  22  * "Software"), to deal in the Software without restriction, including
  23  * without limitation the rights to use, copy, modify, merge, publish,
  24  * distribute, sublicense, and/or sell copies of the Software, and to
  25  * permit persons to whom the Software is furnished to do so, subject to
  26  * the following conditions:
  27  *
  28  * The above copyright notice and this permission notice shall be
  29  * included in all copies or substantial portions of the Software.
  30  *
  31  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  32  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  33  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  34  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  35  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  36  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  37  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  38  */
  39
  40 #ifndef included_ip_lookup_h
  41 #define included_ip_lookup_h
  42
  43 #include <vnet/vnet.h>
  44 #include <vlib/buffer.h>
  45 #include <vnet/ip/ip4_packet.h>
  46 #include <vnet/ip/ip6_packet.h>
  47
  48 /* Common (IP4/IP6) next index stored in adjacency. */
  49 typedef enum {
  50   /* Packet does not match any route in table. */
  51   IP_LOOKUP_NEXT_MISS,
  52
  53   /* Adjacency says to drop or punt this packet. */
  54   IP_LOOKUP_NEXT_DROP,
  55   IP_LOOKUP_NEXT_PUNT,
  56
  57   /* This packet is for one of our own IP addresses. */
  58   IP_LOOKUP_NEXT_LOCAL,
  59
  60   /* This packet matches an "interface route" and packets
  61      need to be passed to ARP to find rewrite string for
  62      this destination. */
  63   IP_LOOKUP_NEXT_ARP,
  64
  65   /* This packet is to be rewritten and forwarded to the next
  66      processing node.  This is typically the output interface but
  67      might be another node for further output processing. */
  68   IP_LOOKUP_NEXT_REWRITE,
  69
  70   /* This packet needs to be classified */
  71   IP_LOOKUP_NEXT_CLASSIFY,
  72
  73   /* This packet needs to go to MAP - RFC7596, RFC7597 */
  74   IP_LOOKUP_NEXT_MAP,
  75
  76   /* This packet needs to go to MAP with Translation - RFC7599 */
  77   IP_LOOKUP_NEXT_MAP_T,
  78
  79   /* This packets needs to go to 6RD (RFC5969) */
  80   IP_LOOKUP_NEXT_SIXRD,
  81
  82   /* This packets needs to go to indirect next hop */
  83   IP_LOOKUP_NEXT_INDIRECT,
  84
  85   IP_LOOKUP_NEXT_ICMP_ERROR,
  86
  87   IP_LOOKUP_N_NEXT,
  88 } ip_lookup_next_t;
  89
  90 typedef enum {
  91   IP4_LOOKUP_N_NEXT = IP_LOOKUP_N_NEXT,
  92 } ip4_lookup_next_t;
  93
  94 typedef enum {
  95   /* Hop-by-hop header handling */
  96   IP6_LOOKUP_NEXT_HOP_BY_HOP = IP_LOOKUP_N_NEXT,
  97   IP6_LOOKUP_NEXT_ADD_HOP_BY_HOP,
  98   IP6_LOOKUP_NEXT_POP_HOP_BY_HOP,
  99   IP6_LOOKUP_N_NEXT,
 100 } ip6_lookup_next_t;
 101
 102 #define IP4_LOOKUP_NEXT_NODES {                                 \
 103     [IP_LOOKUP_NEXT_MISS] = "ip4-miss",                         \
 104     [IP_LOOKUP_NEXT_DROP] = "ip4-drop",                         \
 105     [IP_LOOKUP_NEXT_PUNT] = "ip4-punt",                         \
 106     [IP_LOOKUP_NEXT_LOCAL] = "ip4-local",                       \
 107     [IP_LOOKUP_NEXT_ARP] = "ip4-arp",                           \
 108     [IP_LOOKUP_NEXT_REWRITE] = "ip4-rewrite-transit",           \
 109     [IP_LOOKUP_NEXT_CLASSIFY] = "ip4-classify",                 \
 110     [IP_LOOKUP_NEXT_MAP] = "ip4-map",                           \
 111     [IP_LOOKUP_NEXT_MAP_T] = "ip4-map-t",                       \
 112     [IP_LOOKUP_NEXT_SIXRD] = "ip4-sixrd",                       \
 113     [IP_LOOKUP_NEXT_INDIRECT] = "ip4-indirect",                 \
 114     [IP_LOOKUP_NEXT_ICMP_ERROR] = "ip4-icmp-error",             \
 115 }
 116
 117 #define IP6_LOOKUP_NEXT_NODES {                                 \
 118     [IP_LOOKUP_NEXT_MISS] = "ip6-miss",                         \
 119     [IP_LOOKUP_NEXT_DROP] = "ip6-drop",                         \
 120     [IP_LOOKUP_NEXT_PUNT] = "ip6-punt",                         \
 121     [IP_LOOKUP_NEXT_LOCAL] = "ip6-local",                       \
 122     [IP_LOOKUP_NEXT_ARP] = "ip6-discover-neighbor",             \
 123     [IP_LOOKUP_NEXT_REWRITE] = "ip6-rewrite",                   \
 124     [IP_LOOKUP_NEXT_CLASSIFY] = "ip6-classify",                 \
 125     [IP_LOOKUP_NEXT_MAP] = "ip6-map",                           \
 126     [IP_LOOKUP_NEXT_MAP_T] = "ip6-map-t",                       \
 127     [IP_LOOKUP_NEXT_SIXRD] = "ip6-sixrd",                       \
 128     [IP_LOOKUP_NEXT_INDIRECT] = "ip6-indirect",                 \
 129     [IP_LOOKUP_NEXT_ICMP_ERROR] = "ip6-icmp-error",             \
 130     [IP6_LOOKUP_NEXT_HOP_BY_HOP] = "ip6-hop-by-hop",            \
 131     [IP6_LOOKUP_NEXT_ADD_HOP_BY_HOP] = "ip6-add-hop-by-hop",    \
 132     [IP6_LOOKUP_NEXT_POP_HOP_BY_HOP] = "ip6-pop-hop-by-hop",    \
 133 }
 134
 135 /* Flow hash configuration */
 136 #define IP_FLOW_HASH_SRC_ADDR (1<<0)
 137 #define IP_FLOW_HASH_DST_ADDR (1<<1)
 138 #define IP_FLOW_HASH_PROTO (1<<2)
 139 #define IP_FLOW_HASH_SRC_PORT (1<<3)
 140 #define IP_FLOW_HASH_DST_PORT (1<<4)
 141 #define IP_FLOW_HASH_REVERSE_SRC_DST (1<<5)
 142
 143 /* Default: 5-tuple without the "reverse" bit */
 144 #define IP_FLOW_HASH_DEFAULT (0x1F)
 145
 146 #define foreach_flow_hash_bit                   \
 147 _(src, IP_FLOW_HASH_SRC_ADDR)                   \
 148 _(dst, IP_FLOW_HASH_DST_ADDR)                   \
 149 _(sport, IP_FLOW_HASH_SRC_PORT)                 \
 150 _(dport, IP_FLOW_HASH_DST_PORT)                 \
 151 _(proto, IP_FLOW_HASH_PROTO)                    \
 152 _(reverse, IP_FLOW_HASH_REVERSE_SRC_DST)
 153
 154 /* IP unicast adjacency. */
 155 typedef struct {
 156   CLIB_CACHE_LINE_ALIGN_MARK(cacheline0);
 157   /* Handle for this adjacency in adjacency heap. */
 158   u32 heap_handle;
 159
 160   STRUCT_MARK(signature_start);
 161
 162   /* Interface address index for this local/arp adjacency. */
 163   u32 if_address_index;
 164
 165   /* Number of adjecencies in block.  Greater than 1 means multipath;
 166      otherwise equal to 1. */
 167   u16 n_adj;
 168
 169   /* Next hop after ip4-lookup. */
 170   union {
 171     ip_lookup_next_t lookup_next_index : 16;
 172     u16 lookup_next_index_as_int;
 173   };
 174
 175   /* Force re-lookup in a different FIB. ~0 => normal behavior */
 176   i16 explicit_fib_index;
 177   u16 mcast_group_index;
 178
 179   /* Highest possible perf subgraph arc interposition, e.g. for ip6 ioam */
 180   u16 saved_lookup_next_index;
 181
 182   union {
 183     /* IP_LOOKUP_NEXT_ARP only */
 184     struct {
 185       ip46_address_t next_hop;
 186     } arp;
 187     /* IP_LOOKUP_NEXT_CLASSIFY only */
 188     struct {
 189       u16 table_index;
 190     } classify;
 191     /* IP_LOOKUP_NEXT_INDIRECT only */
 192     struct {
 193         ip46_address_t next_hop;
 194     } indirect;
 195   };
 196
 197   STRUCT_MARK(signature_end);
 198
 199   /* Number of FIB entries sharing this adjacency */
 200   u32 share_count;
 201   /* Use this adjacency instead */
 202   u32 next_adj_with_signature;
 203
 204   CLIB_CACHE_LINE_ALIGN_MARK(cacheline1);
 205
 206   /* Rewrite in second/third cache lines */
 207   vnet_declare_rewrite (VLIB_BUFFER_PRE_DATA_SIZE);
 208 } ip_adjacency_t;
 209
 210 static inline uword
 211 vnet_ip_adjacency_signature (ip_adjacency_t * adj)
 212 {
 213   uword signature = 0xfeedfaceULL;
 214
 215   /* Skip heap handle, sum everything up to but not including share_count */
 216   signature = hash_memory
 217       (STRUCT_MARK_PTR(adj, signature_start),
 218        STRUCT_OFFSET_OF(ip_adjacency_t, signature_end)
 219        - STRUCT_OFFSET_OF(ip_adjacency_t, signature_start),
 220        signature);
 221
 222   /* and the rewrite */
 223   signature = hash_memory (&adj->rewrite_header, VLIB_BUFFER_PRE_DATA_SIZE,
 224                              signature);
 225   return signature;
 226 }
 227
 228 static inline int
 229 vnet_ip_adjacency_share_compare (ip_adjacency_t * a1, ip_adjacency_t *a2)
 230 {
 231   if (memcmp (STRUCT_MARK_PTR(a1, signature_start),
 232               STRUCT_MARK_PTR(a2, signature_start),
 233               STRUCT_OFFSET_OF(ip_adjacency_t, signature_end)
 234               - STRUCT_OFFSET_OF(ip_adjacency_t, signature_start)))
 235     return 0;
 236   if (memcmp (&a1->rewrite_header, &a2->rewrite_header,
 237               VLIB_BUFFER_PRE_DATA_SIZE))
 238     return 0;
 239   return 1;
 240 }
 241
 242 /* Index into adjacency table. */
 243 typedef u32 ip_adjacency_index_t;
 244
 245 typedef struct {
 246   /* Directly connected next-hop adjacency index. */
 247   u32 next_hop_adj_index;
 248
 249   /* Path weight for this adjacency. */
 250   u32 weight;
 251 } ip_multipath_next_hop_t;
 252
 253 typedef struct {
 254   /* Adjacency index of first index in block. */
 255   u32 adj_index;
 256
 257   /* Power of 2 size of adjacency block. */
 258   u32 n_adj_in_block;
 259
 260   /* Number of prefixes that point to this adjacency. */
 261   u32 reference_count;
 262
 263   /* Normalized next hops are used as hash keys: they are sorted by weight
 264      and weights are chosen so they add up to 1 << log2_n_adj_in_block (with
 265      zero-weighted next hops being deleted).
 266      Unnormalized next hops are saved so that control plane has a record of exactly
 267      what the RIB told it. */
 268   struct {
 269     /* Number of hops in the multipath. */
 270     u32 count;
 271
 272     /* Offset into next hop heap for this block. */
 273     u32 heap_offset;
 274
 275     /* Heap handle used to for example free block when we're done with it. */
 276     u32 heap_handle;
 277   } normalized_next_hops, unnormalized_next_hops;
 278 } ip_multipath_adjacency_t;
 279
 280 /* IP multicast adjacency. */
 281 typedef struct {
 282   /* Handle for this adjacency in adjacency heap. */
 283   u32 heap_handle;
 284
 285   /* Number of adjecencies in block. */
 286   u32 n_adj;
 287
 288   /* Rewrite string. */
 289   vnet_declare_rewrite (64 - 2*sizeof(u32));
 290 } ip_multicast_rewrite_t;
 291
 292 typedef struct {
 293   /* ip4-multicast-rewrite next index. */
 294   u32 next_index;
 295
 296   u8 n_rewrite_bytes;
 297
 298   u8 rewrite_string[64 - 1*sizeof(u32) - 1*sizeof(u8)];
 299 } ip_multicast_rewrite_string_t;
 300
 301 typedef struct {
 302   ip_multicast_rewrite_t * rewrite_heap;
 303
 304   ip_multicast_rewrite_string_t * rewrite_strings;
 305
 306   /* Negative rewrite string index; >= 0 sw_if_index.
 307      Sorted.  Used to hash. */
 308   i32 ** adjacency_id_vector;
 309
 310   uword * adjacency_by_id_vector;
 311 } ip_multicast_lookup_main_t;
 312
 313 typedef struct {
 314   /* Key for mhash; in fact, just a byte offset into mhash key vector. */
 315   u32 address_key;
 316
 317   /* Interface which has this address. */
 318   u32 sw_if_index;
 319
 320   /* Adjacency for neighbor probe (ARP) for this interface address. */
 321   u32 neighbor_probe_adj_index;
 322
 323   /* Address (prefix) length for this interface. */
 324   u16 address_length;
 325
 326   /* Will be used for something eventually.  Primary vs. secondary? */
 327   u16 flags;
 328
 329   /* Next and previous pointers for doubly linked list of
 330      addresses per software interface. */
 331   u32 next_this_sw_interface;
 332   u32 prev_this_sw_interface;
 333 } ip_interface_address_t;
 334
 335 typedef enum {
 336   IP_LOCAL_NEXT_DROP,
 337   IP_LOCAL_NEXT_PUNT,
 338   IP_LOCAL_NEXT_UDP_LOOKUP,
 339   IP_LOCAL_NEXT_ICMP,
 340   IP_LOCAL_N_NEXT,
 341 } ip_local_next_t;
 342
 343 struct ip_lookup_main_t;
 344
 345 typedef void (* ip_add_del_adjacency_callback_t) (struct ip_lookup_main_t * lm,
 346                                                   u32 adj_index,
 347                                                   ip_adjacency_t * adj,
 348                                                   u32 is_del);
 349
 350 typedef struct {
 351   vnet_config_main_t config_main;
 352
 353   u32 * config_index_by_sw_if_index;
 354 } ip_config_main_t;
 355
 356 typedef struct ip_lookup_main_t {
 357   /* Adjacency heap. */
 358   ip_adjacency_t * adjacency_heap;
 359
 360   /* Adjacency packet/byte counters indexed by adjacency index. */
 361   vlib_combined_counter_main_t adjacency_counters;
 362
 363   /* Heap of (next hop, weight) blocks.  Sorted by next hop. */
 364   ip_multipath_next_hop_t * next_hop_heap;
 365
 366   /* Indexed by heap_handle from ip_adjacency_t. */
 367   ip_multipath_adjacency_t * multipath_adjacencies;
 368
 369   /* Adjacency by signature hash */
 370   uword * adj_index_by_signature;
 371
 372   /* Temporary vectors for looking up next hops in hash. */
 373   ip_multipath_next_hop_t * next_hop_hash_lookup_key;
 374   ip_multipath_next_hop_t * next_hop_hash_lookup_key_normalized;
 375
 376   /* Hash table mapping normalized next hops and weights
 377      to multipath adjacency index. */
 378   uword * multipath_adjacency_by_next_hops;
 379
 380   u32 * adjacency_remap_table;
 381   u32 n_adjacency_remaps;
 382
 383   /* If average error per adjacency is less than this threshold adjacency block
 384      size is accepted. */
 385   f64 multipath_next_hop_error_tolerance;
 386
 387   /* Adjacency index for routing table misses, local punts, and drops. */
 388   u32 miss_adj_index, drop_adj_index, local_adj_index;
 389
 390   /* Miss adjacency is always first in adjacency table. */
 391 #define IP_LOOKUP_MISS_ADJ_INDEX 0
 392
 393   ip_add_del_adjacency_callback_t * add_del_adjacency_callbacks;
 394
 395   /* Pool of addresses that are assigned to interfaces. */
 396   ip_interface_address_t * if_address_pool;
 397
 398   /* Hash table mapping address to index in interface address pool. */
 399   mhash_t address_to_if_address_index;
 400
 401   /* Head of doubly linked list of interface addresses for each software interface.
 402      ~0 means this interface has no address. */
 403   u32 * if_address_pool_index_by_sw_if_index;
 404
 405   /* First table index to use for this interface, ~0 => none */
 406   u32 * classify_table_index_by_sw_if_index;
 407
 408   /* rx/tx interface/feature configuration. */
 409   ip_config_main_t rx_config_mains[VNET_N_CAST], tx_config_main;
 410
 411   /* Number of bytes in a fib result.  Must be at least
 412      sizeof (uword).  First word is always adjacency index. */
 413   u32 fib_result_n_bytes, fib_result_n_words;
 414
 415   format_function_t * format_fib_result;
 416
 417   /* 1 for ip6; 0 for ip4. */
 418   u32 is_ip6;
 419
 420   /* Either format_ip4_address_and_length or format_ip6_address_and_length. */
 421   format_function_t * format_address_and_length;
 422
 423   /* Table mapping ip protocol to ip[46]-local node next index. */
 424   u8 local_next_by_ip_protocol[256];
 425
 426   /* IP_BUILTIN_PROTOCOL_{TCP,UDP,ICMP,OTHER} by protocol in IP header. */
 427   u8 builtin_protocol_by_ip_protocol[256];
 428 } ip_lookup_main_t;
 429
 430 always_inline ip_adjacency_t *
 431 ip_get_adjacency (ip_lookup_main_t * lm,
 432                   u32 adj_index)
 433 {
 434   ip_adjacency_t * adj;
 435
 436   adj = vec_elt_at_index (lm->adjacency_heap, adj_index);
 437
 438   ASSERT (adj->heap_handle != ~0);
 439
 440   return adj;
 441 }
 442
 443 #define ip_prefetch_adjacency(lm,adj_index,type)                \
 444 do {                                                            \
 445   ip_adjacency_t * _adj = (lm)->adjacency_heap + (adj_index);   \
 446   CLIB_PREFETCH (_adj, sizeof (_adj[0]), type);                 \
 447 } while (0)
 448
 449 static inline void
 450 ip_register_add_del_adjacency_callback(ip_lookup_main_t * lm,
 451                                        ip_add_del_adjacency_callback_t cb)
 452 {
 453   vec_add1(lm->add_del_adjacency_callbacks, cb);
 454 }
 455
 456 always_inline void
 457 ip_call_add_del_adjacency_callbacks (ip_lookup_main_t * lm, u32 adj_index, u32 is_del)
 458 {
 459   ip_adjacency_t * adj;
 460   uword i;
 461   adj = ip_get_adjacency (lm, adj_index);
 462   for (i = 0; i < vec_len (lm->add_del_adjacency_callbacks); i++)
 463     lm->add_del_adjacency_callbacks[i] (lm, adj_index, adj, is_del);
 464 }
 465
 466 /* Create new block of given number of contiguous adjacencies. */
 467 ip_adjacency_t *
 468 ip_add_adjacency (ip_lookup_main_t * lm,
 469                   ip_adjacency_t * adj,
 470                   u32 n_adj,
 471                   u32 * adj_index_result);
 472
 473 void ip_del_adjacency (ip_lookup_main_t * lm, u32 adj_index);
 474 void
 475 ip_update_adjacency (ip_lookup_main_t * lm,
 476                      u32 adj_index,
 477                      ip_adjacency_t * copy_adj);
 478
 479 static inline int
 480 ip_adjacency_is_multipath(ip_lookup_main_t * lm, u32 adj_index)
 481 {
 482   if (!vec_len(lm->multipath_adjacencies))
 483     return 0;
 484
 485   if (vec_len(lm->multipath_adjacencies) < adj_index - 1)
 486     return 0;
 487
 488
 489   return (lm->multipath_adjacencies[adj_index].adj_index == adj_index &&
 490           lm->multipath_adjacencies[adj_index].n_adj_in_block > 0);
 491 }
 492
 493 void
 494 ip_multipath_adjacency_free (ip_lookup_main_t * lm,
 495                              ip_multipath_adjacency_t * a);
 496
 497 u32
 498 ip_multipath_adjacency_add_del_next_hop (ip_lookup_main_t * lm,
 499                                          u32 is_del,
 500                                          u32 old_mp_adj_index,
 501                                          u32 next_hop_adj_index,
 502                                          u32 next_hop_weight,
 503                                          u32 * new_mp_adj_index);
 504
 505 clib_error_t *
 506 ip_interface_address_add_del (ip_lookup_main_t * lm,
 507                               u32 sw_if_index,
 508                               void * address,
 509                               u32 address_length,
 510                               u32 is_del,
 511                               u32 * result_index);
 512
 513 always_inline ip_interface_address_t *
 514 ip_get_interface_address (ip_lookup_main_t * lm, void * addr_fib)
 515 {
 516   uword * p = mhash_get (&lm->address_to_if_address_index, addr_fib);
 517   return p ? pool_elt_at_index (lm->if_address_pool, p[0]) : 0;
 518 }
 519
 520 always_inline void *
 521 ip_interface_address_get_address (ip_lookup_main_t * lm, ip_interface_address_t * a)
 522 { return mhash_key_to_mem (&lm->address_to_if_address_index, a->address_key); }
 523
 524 always_inline ip_interface_address_t *
 525 ip_interface_address_for_packet (ip_lookup_main_t * lm, vlib_buffer_t * b, u32 sw_if_index)
 526 {
 527   ip_adjacency_t * adj;
 528   u32 if_address_index;
 529
 530   adj = ip_get_adjacency (lm, vnet_buffer (b)->ip.adj_index[VLIB_TX]);
 531
 532   ASSERT (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP
 533           || adj->lookup_next_index == IP_LOOKUP_NEXT_LOCAL);
 534   if_address_index = adj->if_address_index;
 535   if_address_index = (if_address_index == ~0 ?
 536                       vec_elt (lm->if_address_pool_index_by_sw_if_index, sw_if_index)
 537                       : if_address_index);
 538
 539   return pool_elt_at_index (lm->if_address_pool, if_address_index);
 540 }
 541
 542 #define foreach_ip_interface_address(lm,a,sw_if_index,loop,body)        \
 543 do {                                                                    \
 544     vnet_main_t *_vnm = vnet_get_main();                                     \
 545     u32 _sw_if_index = sw_if_index;                                     \
 546     vnet_sw_interface_t *_swif;                                         \
 547     _swif = vnet_get_sw_interface (_vnm, _sw_if_index);                 \
 548                                                                         \
 549     /*                                                                  \
 550      * Loop => honor unnumbered interface addressing.                   \
 551      */                                                                 \
 552     if (loop && _swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)       \
 553       _sw_if_index = _swif->unnumbered_sw_if_index;                     \
 554     u32 _ia =                                                           \
 555       (vec_len((lm)->if_address_pool_index_by_sw_if_index)              \
 556        > (_sw_if_index))                                                \
 557         ? vec_elt ((lm)->if_address_pool_index_by_sw_if_index,          \
 558                    (_sw_if_index)) : (u32)~0;                           \
 559     ip_interface_address_t * _a;                                        \
 560     while (_ia != ~0)                                                   \
 561     {                                                                   \
 562         _a = pool_elt_at_index ((lm)->if_address_pool, _ia);            \
 563         _ia = _a->next_this_sw_interface;                               \
 564         (a) = _a;                                                       \
 565         body;                                                           \
 566     }                                                                   \
 567 } while (0)
 568
 569 void ip_lookup_init (ip_lookup_main_t * lm, u32 ip_lookup_node_index);
 570
 571 #endif /* included_ip_lookup_h */