src/vnet/fib/ip4_fib.c

   1 /*
   2  * Copyright (c) 2016 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 #include <vnet/fib/fib_table.h>
  17 #include <vnet/fib/fib_entry.h>
  18 #include <vnet/fib/ip4_fib.h>
  19
  20 /*
  21  * A table of prefixes to be added to tables and the sources for them
  22  */
  23 typedef struct ip4_fib_table_special_prefix_t_ {
  24     fib_prefix_t ift_prefix;
  25     fib_source_t ift_source;
  26     fib_entry_flag_t ift_flag;
  27 } ip4_fib_table_special_prefix_t;
  28
  29 static const ip4_fib_table_special_prefix_t ip4_specials[] = {
  30     {
  31         /* 0.0.0.0/0*/
  32         .ift_prefix = {
  33             .fp_addr = {
  34                 .ip4.data_u32 = 0,
  35             },
  36             .fp_len  = 0,
  37             .fp_proto = FIB_PROTOCOL_IP4,
  38         },
  39         .ift_source = FIB_SOURCE_DEFAULT_ROUTE,
  40         .ift_flag   = FIB_ENTRY_FLAG_DROP,
  41     },
  42     {
  43         /* 0.0.0.0/32*/
  44         .ift_prefix = {
  45             .fp_addr = {
  46                 .ip4.data_u32 = 0,
  47             },
  48             .fp_len  = 32,
  49             .fp_proto = FIB_PROTOCOL_IP4,
  50         },
  51         .ift_source = FIB_SOURCE_DEFAULT_ROUTE,
  52         .ift_flag   = FIB_ENTRY_FLAG_DROP,
  53     },
  54     {
  55         /*
  56          * 240.0.0.0/4
  57          * drop class E
  58          */
  59         .ift_prefix = {
  60             .fp_addr = {
  61                 .ip4.data_u32 = 0xf0000000,
  62             },
  63             .fp_len   = 4,
  64             .fp_proto = FIB_PROTOCOL_IP4,
  65         },
  66         .ift_source = FIB_SOURCE_SPECIAL,
  67         .ift_flag   = FIB_ENTRY_FLAG_DROP,
  68
  69     },
  70     {
  71         /*
  72          * 224.0.0.0/4
  73          * drop all mcast
  74          */
  75         .ift_prefix = {
  76             .fp_addr = {
  77                 .ip4.data_u32 = 0xe0000000,
  78             },
  79             .fp_len   = 4,
  80             .fp_proto = FIB_PROTOCOL_IP4,
  81         },
  82         .ift_source = FIB_SOURCE_SPECIAL,
  83         .ift_flag    = FIB_ENTRY_FLAG_DROP,
  84     },
  85     {
  86         /*
  87          * 255.255.255.255/32
  88          * drop, but we'll allow it to be usurped by the likes of DHCP
  89          */
  90         .ift_prefix = {
  91             .fp_addr = {
  92                 .ip4.data_u32 = 0xffffffff,
  93             },
  94             .fp_len   = 32,
  95             .fp_proto = FIB_PROTOCOL_IP4,
  96         },
  97         .ift_source = FIB_SOURCE_DEFAULT_ROUTE,
  98         .ift_flag   = FIB_ENTRY_FLAG_DROP,
  99     }
 100 };
 101
 102
 103 static u32
 104 ip4_create_fib_with_table_id (u32 table_id,
 105                               fib_source_t src)
 106 {
 107     fib_table_t *fib_table;
 108     ip4_fib_t *v4_fib;
 109
 110     pool_get(ip4_main.fibs, fib_table);
 111     clib_memset(fib_table, 0, sizeof(*fib_table));
 112
 113     pool_get_aligned(ip4_main.v4_fibs, v4_fib, CLIB_CACHE_LINE_BYTES);
 114
 115     ASSERT((fib_table - ip4_main.fibs) ==
 116            (v4_fib - ip4_main.v4_fibs));
 117
 118     fib_table->ft_proto = FIB_PROTOCOL_IP4;
 119     fib_table->ft_index =
 120         v4_fib->index =
 121             (fib_table - ip4_main.fibs);
 122
 123     hash_set (ip4_main.fib_index_by_table_id, table_id, fib_table->ft_index);
 124
 125     fib_table->ft_table_id =
 126         v4_fib->table_id =
 127             table_id;
 128     fib_table->ft_flow_hash_config = IP_FLOW_HASH_DEFAULT;
 129
 130     fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP4, src);
 131
 132     ip4_mtrie_16_init(&v4_fib->mtrie);
 133
 134     /*
 135      * add the special entries into the new FIB
 136      */
 137     int ii;
 138
 139     for (ii = 0; ii < ARRAY_LEN(ip4_specials); ii++)
 140     {
 141         fib_prefix_t prefix = ip4_specials[ii].ift_prefix;
 142
 143         prefix.fp_addr.ip4.data_u32 =
 144             clib_host_to_net_u32(prefix.fp_addr.ip4.data_u32);
 145
 146         fib_table_entry_special_add(fib_table->ft_index,
 147                                     &prefix,
 148                                     ip4_specials[ii].ift_source,
 149                                     ip4_specials[ii].ift_flag);
 150     }
 151
 152     return (fib_table->ft_index);
 153 }
 154
 155 void
 156 ip4_fib_table_destroy (u32 fib_index)
 157 {
 158     fib_table_t *fib_table = pool_elt_at_index(ip4_main.fibs, fib_index);
 159     ip4_fib_t *v4_fib = pool_elt_at_index(ip4_main.v4_fibs, fib_index);
 160     u32 *n_locks;
 161     int ii;
 162
 163     /*
 164      * remove all the specials we added when the table was created.
 165      * In reverse order so the default route is last.
 166      */
 167     for (ii = ARRAY_LEN(ip4_specials) - 1; ii >= 0; ii--)
 168     {
 169         fib_prefix_t prefix = ip4_specials[ii].ift_prefix;
 170
 171         prefix.fp_addr.ip4.data_u32 =
 172             clib_host_to_net_u32(prefix.fp_addr.ip4.data_u32);
 173
 174         fib_table_entry_special_remove(fib_table->ft_index,
 175                                        &prefix,
 176                                        ip4_specials[ii].ift_source);
 177     }
 178
 179     /*
 180      * validate no more routes.
 181      */
 182 #if CLIB_DEBUG > 0
 183     if (0 != fib_table->ft_total_route_counts)
 184         fib_table_assert_empty(fib_table);
 185 #endif
 186
 187     vec_foreach(n_locks, fib_table->ft_src_route_counts)
 188     {
 189         ASSERT(0 == *n_locks);
 190     }
 191
 192     if (~0 != fib_table->ft_table_id)
 193     {
 194         hash_unset (ip4_main.fib_index_by_table_id, fib_table->ft_table_id);
 195     }
 196
 197     vec_free(fib_table->ft_src_route_counts);
 198     ip4_mtrie_16_free(&v4_fib->mtrie);
 199
 200     pool_put(ip4_main.v4_fibs, v4_fib);
 201     pool_put(ip4_main.fibs, fib_table);
 202 }
 203
 204
 205 u32
 206 ip4_fib_table_find_or_create_and_lock (u32 table_id,
 207                                        fib_source_t src)
 208 {
 209     u32 index;
 210
 211     index = ip4_fib_index_from_table_id(table_id);
 212     if (~0 == index)
 213         return ip4_create_fib_with_table_id(table_id, src);
 214
 215     fib_table_lock(index, FIB_PROTOCOL_IP4, src);
 216
 217     return (index);
 218 }
 219
 220 u32
 221 ip4_fib_table_create_and_lock (fib_source_t src)
 222 {
 223     return (ip4_create_fib_with_table_id(~0, src));
 224 }
 225
 226 u32
 227 ip4_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
 228 {
 229     if (sw_if_index >= vec_len(ip4_main.fib_index_by_sw_if_index))
 230     {
 231         /*
 232          * This is the case for interfaces that are not yet mapped to
 233          * a IP table
 234          */
 235         return (~0);
 236     }
 237     return (ip4_main.fib_index_by_sw_if_index[sw_if_index]);
 238 }
 239
 240 /*
 241  * ip4_fib_table_lookup_exact_match
 242  *
 243  * Exact match prefix lookup
 244  */
 245 fib_node_index_t
 246 ip4_fib_table_lookup_exact_match (const ip4_fib_t *fib,
 247                                   const ip4_address_t *addr,
 248                                   u32 len)
 249 {
 250     uword * hash, * result;
 251     u32 key;
 252
 253     hash = fib->fib_entry_by_dst_address[len];
 254     key  = (addr->data_u32 & ip4_main.fib_masks[len]);
 255
 256     result = hash_get(hash, key);
 257
 258     if (NULL != result) {
 259         return (result[0]);
 260     }
 261     return (FIB_NODE_INDEX_INVALID);
 262 }
 263
 264 /*
 265  * ip4_fib_table_lookup_adj
 266  *
 267  * Longest prefix match
 268  */
 269 index_t
 270 ip4_fib_table_lookup_lb (ip4_fib_t *fib,
 271                          const ip4_address_t *addr)
 272 {
 273     fib_node_index_t fei;
 274
 275     fei = ip4_fib_table_lookup(fib, addr, 32);
 276
 277     if (FIB_NODE_INDEX_INVALID != fei)
 278     {
 279         const dpo_id_t *dpo;
 280
 281         dpo = fib_entry_contribute_ip_forwarding(fei);
 282
 283         return (dpo->dpoi_index);
 284     }
 285     return (INDEX_INVALID);
 286 }
 287
 288 /*
 289  * ip4_fib_table_lookup
 290  *
 291  * Longest prefix match
 292  */
 293 fib_node_index_t
 294 ip4_fib_table_lookup (const ip4_fib_t *fib,
 295                       const ip4_address_t *addr,
 296                       u32 len)
 297 {
 298     uword * hash, * result;
 299     i32 mask_len;
 300     u32 key;
 301
 302     for (mask_len = len; mask_len >= 0; mask_len--)
 303     {
 304         hash = fib->fib_entry_by_dst_address[mask_len];
 305         key = (addr->data_u32 & ip4_main.fib_masks[mask_len]);
 306
 307         result = hash_get (hash, key);
 308
 309         if (NULL != result) {
 310             return (result[0]);
 311         }
 312     }
 313     return (FIB_NODE_INDEX_INVALID);
 314 }
 315
 316 void
 317 ip4_fib_table_entry_insert (ip4_fib_t *fib,
 318                             const ip4_address_t *addr,
 319                             u32 len,
 320                             fib_node_index_t fib_entry_index)
 321 {
 322     uword * hash, * result;
 323     u32 key;
 324
 325     key = (addr->data_u32 & ip4_main.fib_masks[len]);
 326     hash = fib->fib_entry_by_dst_address[len];
 327     result = hash_get (hash, key);
 328
 329     if (NULL == result) {
 330         /*
 331          * adding a new entry
 332          */
 333
 334         if (NULL == hash) {
 335             hash = hash_create (32 /* elts */, sizeof (uword));
 336             hash_set_flags (hash, HASH_FLAG_NO_AUTO_SHRINK);
 337
 338         }
 339         hash = hash_set(hash, key, fib_entry_index);
 340         fib->fib_entry_by_dst_address[len] = hash;
 341     }
 342     else
 343     {
 344         ASSERT(0);
 345     }
 346 }
 347
 348 void
 349 ip4_fib_table_entry_remove (ip4_fib_t *fib,
 350                             const ip4_address_t *addr,
 351                             u32 len)
 352 {
 353     uword * hash, * result;
 354     u32 key;
 355
 356     key = (addr->data_u32 & ip4_main.fib_masks[len]);
 357     hash = fib->fib_entry_by_dst_address[len];
 358     result = hash_get (hash, key);
 359
 360     if (NULL == result)
 361     {
 362         /*
 363          * removing a non-existent entry. i'll allow it.
 364          */
 365     }
 366     else
 367     {
 368         hash_unset(hash, key);
 369     }
 370
 371     fib->fib_entry_by_dst_address[len] = hash;
 372 }
 373
 374 void
 375 ip4_fib_table_fwding_dpo_update (ip4_fib_t *fib,
 376                                  const ip4_address_t *addr,
 377                                  u32 len,
 378                                  const dpo_id_t *dpo)
 379 {
 380     ip4_mtrie_16_route_add(&fib->mtrie, addr, len, dpo->dpoi_index);
 381 }
 382
 383 void
 384 ip4_fib_table_fwding_dpo_remove (ip4_fib_t *fib,
 385                                  const ip4_address_t *addr,
 386                                  u32 len,
 387                                  const dpo_id_t *dpo,
 388                                  u32 cover_index)
 389 {
 390     const fib_prefix_t *cover_prefix;
 391     const dpo_id_t *cover_dpo;
 392
 393     /*
 394      * We need to pass the MTRIE the LB index and address length of the
 395      * covering prefix, so it can fill the plys with the correct replacement
 396      * for the entry being removed
 397      */
 398     cover_prefix = fib_entry_get_prefix(cover_index);
 399     cover_dpo = fib_entry_contribute_ip_forwarding(cover_index);
 400
 401     ip4_mtrie_16_route_del(&fib->mtrie,
 402                             addr, len, dpo->dpoi_index,
 403                             cover_prefix->fp_len,
 404                             cover_dpo->dpoi_index);
 405 }
 406
 407 void
 408 ip4_fib_table_walk (ip4_fib_t *fib,
 409                     fib_table_walk_fn_t fn,
 410                     void *ctx)
 411 {
 412     fib_prefix_t root = {
 413         .fp_proto = FIB_PROTOCOL_IP4,
 414         // address and length default to all 0
 415     };
 416
 417     /*
 418      * A full tree walk is the dengenerate case of a sub-tree from
 419      * the very root
 420      */
 421     return (ip4_fib_table_sub_tree_walk(fib, &root, fn, ctx));
 422 }
 423
 424 void
 425 ip4_fib_table_sub_tree_walk (ip4_fib_t *fib,
 426                              const fib_prefix_t *root,
 427                              fib_table_walk_fn_t fn,
 428                              void *ctx)
 429 {
 430     fib_prefix_t *sub_trees = NULL;
 431     int i;
 432
 433     /*
 434      * There is no efficient way to walk this array of hash tables.
 435      * so we walk each table with a mask length greater than and equal to
 436      * the required root and check it is covered by the root.
 437      */
 438     for (i = root->fp_len;
 439          i < ARRAY_LEN (fib->fib_entry_by_dst_address);
 440          i++)
 441     {
 442         uword * hash = fib->fib_entry_by_dst_address[i];
 443
 444         if (NULL != hash)
 445         {
 446             ip4_address_t key;
 447             hash_pair_t * p;
 448
 449             hash_foreach_pair (p, hash,
 450             ({
 451                 key.as_u32 = p->key;
 452                 if (ip4_destination_matches_route(&ip4_main,
 453                                                   &key,
 454                                                   &root->fp_addr.ip4,
 455                                                   root->fp_len))
 456                 {
 457                     const fib_prefix_t *sub_tree;
 458                     int skip = 0;
 459
 460                     /*
 461                      * exclude sub-trees the walk does not want to explore
 462                      */
 463                     vec_foreach(sub_tree, sub_trees)
 464                     {
 465                         if (ip4_destination_matches_route(&ip4_main,
 466                                                           &key,
 467                                                           &sub_tree->fp_addr.ip4,
 468                                                           sub_tree->fp_len))
 469                         {
 470                             skip = 1;
 471                             break;
 472                         }
 473                     }
 474
 475                     if (!skip)
 476                     {
 477                         switch (fn(p->value[0], ctx))
 478                         {
 479                         case FIB_TABLE_WALK_CONTINUE:
 480                             break;
 481                         case FIB_TABLE_WALK_SUB_TREE_STOP: {
 482                             fib_prefix_t pfx = {
 483                                 .fp_proto = FIB_PROTOCOL_IP4,
 484                                 .fp_len = i,
 485                                 .fp_addr.ip4 = key,
 486                             };
 487                             vec_add1(sub_trees, pfx);
 488                             break;
 489                         }
 490                         case FIB_TABLE_WALK_STOP:
 491                             goto done;
 492                         }
 493                     }
 494                 }
 495             }));
 496         }
 497     }
 498 done:
 499     vec_free(sub_trees);
 500     return;
 501 }
 502
 503 /**
 504  * Walk show context
 505  */
 506 typedef struct ip4_fib_show_walk_ctx_t_
 507 {
 508     fib_node_index_t *ifsw_indicies;
 509 } ip4_fib_show_walk_ctx_t;
 510
 511 static fib_table_walk_rc_t
 512 ip4_fib_show_walk_cb (fib_node_index_t fib_entry_index,
 513                       void *arg)
 514 {
 515     ip4_fib_show_walk_ctx_t *ctx = arg;
 516
 517     vec_add1(ctx->ifsw_indicies, fib_entry_index);
 518
 519     return (FIB_TABLE_WALK_CONTINUE);
 520 }
 521
 522 static void
 523 ip4_fib_table_show_all (ip4_fib_t *fib,
 524                         vlib_main_t * vm)
 525 {
 526     ip4_fib_show_walk_ctx_t ctx = {
 527         .ifsw_indicies = NULL,
 528     };
 529     fib_node_index_t *fib_entry_index;
 530
 531     ip4_fib_table_walk(fib, ip4_fib_show_walk_cb, &ctx);
 532     vec_sort_with_function(ctx.ifsw_indicies,
 533                            fib_entry_cmp_for_sort);
 534
 535     vec_foreach(fib_entry_index, ctx.ifsw_indicies)
 536     {
 537         vlib_cli_output(vm, "%U",
 538                         format_fib_entry,
 539                         *fib_entry_index,
 540                         FIB_ENTRY_FORMAT_BRIEF);
 541     }
 542
 543     vec_free(ctx.ifsw_indicies);
 544 }
 545
 546 static void
 547 ip4_fib_table_show_one (ip4_fib_t *fib,
 548                         vlib_main_t * vm,
 549                         ip4_address_t *address,
 550                         u32 mask_len,
 551                         int detail)
 552 {
 553     vlib_cli_output(vm, "%U",
 554                     format_fib_entry,
 555                     ip4_fib_table_lookup(fib, address, mask_len),
 556                     (detail ?
 557                      FIB_ENTRY_FORMAT_DETAIL2 :
 558                      FIB_ENTRY_FORMAT_DETAIL));
 559 }
 560
 561 u8 *
 562 format_ip4_fib_table_memory (u8 * s, va_list * args)
 563 {
 564     s = format(s, "%=30s %=6d\n",
 565                "IPv4 unicast",
 566                pool_elts(ip4_main.fibs));
 567     return (s);
 568 }
 569
 570 static clib_error_t *
 571 ip4_show_fib (vlib_main_t * vm,
 572               unformat_input_t * input,
 573               vlib_cli_command_t * cmd)
 574 {
 575     ip4_main_t * im4 = &ip4_main;
 576     fib_table_t * fib_table;
 577     u64 total_mtrie_memory, total_hash_memory;
 578     int verbose, matching, mtrie, memory;
 579     ip4_address_t matching_address;
 580     u32 matching_mask = 32;
 581     int i, table_id = -1, fib_index = ~0;
 582     int detail = 0;
 583
 584     verbose = 1;
 585     matching = mtrie = memory = 0;
 586     total_hash_memory = total_mtrie_memory = 0;
 587
 588     while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 589     {
 590         if (unformat (input, "brief") || unformat (input, "summary")
 591             || unformat (input, "sum"))
 592             verbose = 0;
 593
 594         else if (unformat (input, "detail") || unformat (input, "det"))
 595             detail = 1;
 596
 597         else if (unformat (input, "mtrie"))
 598             mtrie = 1;
 599
 600         else if (unformat (input, "mem") ||
 601                  unformat (input, "memory"))
 602             memory = 1;
 603
 604         else if (unformat (input, "%U/%d",
 605                            unformat_ip4_address, &matching_address, &matching_mask))
 606             matching = 1;
 607
 608         else if (unformat (input, "%U", unformat_ip4_address, &matching_address))
 609             matching = 1;
 610
 611         else if (unformat (input, "table %d", &table_id))
 612             ;
 613         else if (unformat (input, "index %d", &fib_index))
 614             ;
 615         else
 616             break;
 617     }
 618
 619     pool_foreach (fib_table, im4->fibs)
 620      {
 621         ip4_fib_t *fib = pool_elt_at_index(im4->v4_fibs, fib_table->ft_index);
 622         fib_source_t source;
 623         u8 *s = NULL;
 624
 625         if (table_id >= 0 && table_id != (int)fib->table_id)
 626             continue;
 627         if (fib_index != ~0 && fib_index != (int)fib->index)
 628             continue;
 629
 630         if (memory)
 631         {
 632             uword mtrie_size, hash_size;
 633
 634
 635             mtrie_size = ip4_mtrie_16_memory_usage(&fib->mtrie);
 636             hash_size = 0;
 637
 638             for (i = 0; i < ARRAY_LEN (fib->fib_entry_by_dst_address); i++)
 639             {
 640                 uword * hash = fib->fib_entry_by_dst_address[i];
 641                 if (NULL != hash)
 642                 {
 643                     hash_size += hash_bytes(hash);
 644                 }
 645             }
 646
 647             if (verbose)
 648                 vlib_cli_output (vm, "%U mtrie:%d hash:%d",
 649                                  format_fib_table_name, fib->index,
 650                                  FIB_PROTOCOL_IP4,
 651                                  mtrie_size,
 652                                  hash_size);
 653             total_mtrie_memory += mtrie_size;
 654             total_hash_memory += hash_size;
 655             continue;
 656         }
 657
 658         s = format(s, "%U, fib_index:%d, flow hash:[%U] epoch:%d flags:%U locks:[",
 659                    format_fib_table_name, fib->index,
 660                    FIB_PROTOCOL_IP4,
 661                    fib->index,
 662                    format_ip_flow_hash_config,
 663                    fib_table->ft_flow_hash_config,
 664                    fib_table->ft_epoch,
 665                    format_fib_table_flags, fib_table->ft_flags);
 666         vec_foreach_index(source, fib_table->ft_locks)
 667         {
 668             if (0 != fib_table->ft_locks[source])
 669             {
 670                 s = format(s, "%U:%d, ",
 671                            format_fib_source, source,
 672                            fib_table->ft_locks[source]);
 673             }
 674         }
 675         s = format (s, "]");
 676         vlib_cli_output (vm, "%v", s);
 677         vec_free(s);
 678
 679         /* Show summary? */
 680         if (mtrie)
 681         {
 682             vlib_cli_output (vm, "%U", format_ip4_mtrie_16, &fib->mtrie, verbose);
 683             continue;
 684         }
 685         if (! verbose)
 686         {
 687             vlib_cli_output (vm, "%=20s%=16s", "Prefix length", "Count");
 688             for (i = 0; i < ARRAY_LEN (fib->fib_entry_by_dst_address); i++)
 689             {
 690                 uword * hash = fib->fib_entry_by_dst_address[i];
 691                 uword n_elts = hash_elts (hash);
 692                 if (n_elts > 0)
 693                     vlib_cli_output (vm, "%20d%16d", i, n_elts);
 694             }
 695             continue;
 696         }
 697
 698         if (!matching)
 699         {
 700             ip4_fib_table_show_all(fib, vm);
 701         }
 702         else
 703         {
 704             ip4_fib_table_show_one(fib, vm, &matching_address,
 705                                    matching_mask, detail);
 706         }
 707     }
 708
 709     if (memory)
 710     {
 711         vlib_cli_output (vm, "totals: mtrie:%ld hash:%ld all:%ld",
 712                          total_mtrie_memory,
 713                          total_hash_memory,
 714                          total_mtrie_memory + total_hash_memory);
 715     }
 716     return 0;
 717 }
 718
 719 /*?
 720  * This command displays the IPv4 FIB Tables (VRF Tables) and the route
 721  * entries for each table.
 722  *
 723  * @note This command will run for a long time when the FIB tables are
 724  * comprised of millions of entries. For those senarios, consider displaying
 725  * a single table or summary mode.
 726  *
 727  * @cliexpar
 728  * Example of how to display all the IPv4 FIB tables:
 729  * @cliexstart{show ip fib}
 730  * ipv4-VRF:0, fib_index 0, flow hash: src dst sport dport proto
 731  * 0.0.0.0/0
 732  *   unicast-ip4-chain
 733  *   [@0]: dpo-load-balance: [index:0 buckets:1 uRPF:0 to:[0:0]]
 734  *     [0] [@0]: dpo-drop ip6
 735  * 0.0.0.0/32
 736  *   unicast-ip4-chain
 737  *   [@0]: dpo-load-balance: [index:1 buckets:1 uRPF:1 to:[0:0]]
 738  *     [0] [@0]: dpo-drop ip6
 739  * 6.0.1.2/32
 740  *   unicast-ip4-chain
 741  *   [@0]: dpo-load-balance: [index:30 buckets:1 uRPF:29 to:[0:0]]
 742  *     [0] [@3]: arp-ipv4: via 6.0.0.1 af_packet0
 743  * 7.0.0.1/32
 744  *   unicast-ip4-chain
 745  *   [@0]: dpo-load-balance: [index:31 buckets:4 uRPF:30 to:[0:0]]
 746  *     [0] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
 747  *     [1] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
 748  *     [2] [@3]: arp-ipv4: via 6.0.0.2 af_packet0
 749  *     [3] [@3]: arp-ipv4: via 6.0.0.1 af_packet0
 750  * 224.0.0.0/8
 751  *   unicast-ip4-chain
 752  *   [@0]: dpo-load-balance: [index:3 buckets:1 uRPF:3 to:[0:0]]
 753  *     [0] [@0]: dpo-drop ip6
 754  * 240.0.0.0/8
 755  *   unicast-ip4-chain
 756  *   [@0]: dpo-load-balance: [index:2 buckets:1 uRPF:2 to:[0:0]]
 757  *     [0] [@0]: dpo-drop ip6
 758  * 255.255.255.255/32
 759  *   unicast-ip4-chain
 760  *   [@0]: dpo-load-balance: [index:4 buckets:1 uRPF:4 to:[0:0]]
 761  *     [0] [@0]: dpo-drop ip6
 762  * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
 763  * 0.0.0.0/0
 764  *   unicast-ip4-chain
 765  *   [@0]: dpo-load-balance: [index:12 buckets:1 uRPF:11 to:[0:0]]
 766  *     [0] [@0]: dpo-drop ip6
 767  * 0.0.0.0/32
 768  *   unicast-ip4-chain
 769  *   [@0]: dpo-load-balance: [index:13 buckets:1 uRPF:12 to:[0:0]]
 770  *     [0] [@0]: dpo-drop ip6
 771  * 172.16.1.0/24
 772  *   unicast-ip4-chain
 773  *   [@0]: dpo-load-balance: [index:17 buckets:1 uRPF:16 to:[0:0]]
 774  *     [0] [@4]: ipv4-glean: af_packet0
 775  * 172.16.1.1/32
 776  *   unicast-ip4-chain
 777  *   [@0]: dpo-load-balance: [index:18 buckets:1 uRPF:17 to:[1:84]]
 778  *     [0] [@2]: dpo-receive: 172.16.1.1 on af_packet0
 779  * 172.16.1.2/32
 780  *   unicast-ip4-chain
 781  *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
 782  *     [0] [@5]: ipv4 via 172.16.1.2 af_packet0: IP4: 02:fe:9e:70:7a:2b -> 26:a5:f6:9c:3a:36
 783  * 172.16.2.0/24
 784  *   unicast-ip4-chain
 785  *   [@0]: dpo-load-balance: [index:19 buckets:1 uRPF:18 to:[0:0]]
 786  *     [0] [@4]: ipv4-glean: af_packet1
 787  * 172.16.2.1/32
 788  *   unicast-ip4-chain
 789  *   [@0]: dpo-load-balance: [index:20 buckets:1 uRPF:19 to:[0:0]]
 790  *     [0] [@2]: dpo-receive: 172.16.2.1 on af_packet1
 791  * 224.0.0.0/8
 792  *   unicast-ip4-chain
 793  *   [@0]: dpo-load-balance: [index:15 buckets:1 uRPF:14 to:[0:0]]
 794  *     [0] [@0]: dpo-drop ip6
 795  * 240.0.0.0/8
 796  *   unicast-ip4-chain
 797  *   [@0]: dpo-load-balance: [index:14 buckets:1 uRPF:13 to:[0:0]]
 798  *     [0] [@0]: dpo-drop ip6
 799  * 255.255.255.255/32
 800  *   unicast-ip4-chain
 801  *   [@0]: dpo-load-balance: [index:16 buckets:1 uRPF:15 to:[0:0]]
 802  *     [0] [@0]: dpo-drop ip6
 803  * @cliexend
 804  * Example of how to display a single IPv4 FIB table:
 805  * @cliexstart{show ip fib table 7}
 806  * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
 807  * 0.0.0.0/0
 808  *   unicast-ip4-chain
 809  *   [@0]: dpo-load-balance: [index:12 buckets:1 uRPF:11 to:[0:0]]
 810  *     [0] [@0]: dpo-drop ip6
 811  * 0.0.0.0/32
 812  *   unicast-ip4-chain
 813  *   [@0]: dpo-load-balance: [index:13 buckets:1 uRPF:12 to:[0:0]]
 814  *     [0] [@0]: dpo-drop ip6
 815  * 172.16.1.0/24
 816  *   unicast-ip4-chain
 817  *   [@0]: dpo-load-balance: [index:17 buckets:1 uRPF:16 to:[0:0]]
 818  *     [0] [@4]: ipv4-glean: af_packet0
 819  * 172.16.1.1/32
 820  *   unicast-ip4-chain
 821  *   [@0]: dpo-load-balance: [index:18 buckets:1 uRPF:17 to:[1:84]]
 822  *     [0] [@2]: dpo-receive: 172.16.1.1 on af_packet0
 823  * 172.16.1.2/32
 824  *   unicast-ip4-chain
 825  *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
 826  *     [0] [@5]: ipv4 via 172.16.1.2 af_packet0: IP4: 02:fe:9e:70:7a:2b -> 26:a5:f6:9c:3a:36
 827  * 172.16.2.0/24
 828  *   unicast-ip4-chain
 829  *   [@0]: dpo-load-balance: [index:19 buckets:1 uRPF:18 to:[0:0]]
 830  *     [0] [@4]: ipv4-glean: af_packet1
 831  * 172.16.2.1/32
 832  *   unicast-ip4-chain
 833  *   [@0]: dpo-load-balance: [index:20 buckets:1 uRPF:19 to:[0:0]]
 834  *     [0] [@2]: dpo-receive: 172.16.2.1 on af_packet1
 835  * 224.0.0.0/8
 836  *   unicast-ip4-chain
 837  *   [@0]: dpo-load-balance: [index:15 buckets:1 uRPF:14 to:[0:0]]
 838  *     [0] [@0]: dpo-drop ip6
 839  * 240.0.0.0/8
 840  *   unicast-ip4-chain
 841  *   [@0]: dpo-load-balance: [index:14 buckets:1 uRPF:13 to:[0:0]]
 842  *     [0] [@0]: dpo-drop ip6
 843  * 255.255.255.255/32
 844  *   unicast-ip4-chain
 845  *   [@0]: dpo-load-balance: [index:16 buckets:1 uRPF:15 to:[0:0]]
 846  *     [0] [@0]: dpo-drop ip6
 847  * @cliexend
 848  * Example of how to display a summary of all IPv4 FIB tables:
 849  * @cliexstart{show ip fib summary}
 850  * ipv4-VRF:0, fib_index 0, flow hash: src dst sport dport proto
 851  *     Prefix length         Count
 852  *                    0               1
 853  *                    8               2
 854  *                   32               4
 855  * ipv4-VRF:7, fib_index 1, flow hash: src dst sport dport proto
 856  *     Prefix length         Count
 857  *                    0               1
 858  *                    8               2
 859  *                   24               2
 860  *                   32               4
 861  * @cliexend
 862  ?*/
 863 /* *INDENT-OFF* */
 864 VLIB_CLI_COMMAND (ip4_show_fib_command, static) = {
 865     .path = "show ip fib",
 866     .short_help = "show ip fib [summary] [table <table-id>] [index <fib-id>] [<ip4-addr>[/<mask>]] [mtrie] [detail]",
 867     .function = ip4_show_fib,
 868 };
 869 /* *INDENT-ON* */