vnet/vnet/dpo/load_balance.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/ip/lookup.h>
  17 #include <vnet/dpo/load_balance.h>
  18 #include <vnet/dpo/load_balance_map.h>
  19 #include <vnet/dpo/drop_dpo.h>
  20 #include <vppinfra/math.h>              /* for fabs */
  21 #include <vnet/adj/adj.h>
  22 #include <vnet/adj/adj_internal.h>
  23 #include <vnet/fib/fib_urpf_list.h>
  24
  25 /*
  26  * distribution error tolerance for load-balancing
  27  */
  28 const f64 multipath_next_hop_error_tolerance = 0.1;
  29
  30 #undef LB_DEBUG
  31
  32 #ifdef LB_DEBUG
  33 #define LB_DBG(_lb, _fmt, _args...)                                     \
  34 {                                                                       \
  35     u8* _tmp =NULL;                                                     \
  36     clib_warning("lb:[%s]:" _fmt,                                       \
  37                  load_balance_format(load_balance_get_index((_lb)),     \
  38                                      0, _tmp),                          \
  39                  ##_args);                                              \
  40     vec_free(_tmp);                                                     \
  41 }
  42 #else
  43 #define LB_DBG(_p, _fmt, _args...)
  44 #endif
  45
  46
  47 /**
  48  * Pool of all DPOs. It's not static so the DP can have fast access
  49  */
  50 load_balance_t *load_balance_pool;
  51
  52 /**
  53  * The one instance of load-balance main
  54  */
  55 load_balance_main_t load_balance_main;
  56
  57 f64
  58 load_balance_get_multipath_tolerance (void)
  59 {
  60     return (multipath_next_hop_error_tolerance);
  61 }
  62
  63 static inline index_t
  64 load_balance_get_index (const load_balance_t *lb)
  65 {
  66     return (lb - load_balance_pool);
  67 }
  68
  69 static inline dpo_id_t*
  70 load_balance_get_buckets (load_balance_t *lb)
  71 {
  72     if (LB_HAS_INLINE_BUCKETS(lb))
  73     {
  74         return (lb->lb_buckets_inline);
  75     }
  76     else
  77     {
  78         return (lb->lb_buckets);
  79     }
  80 }
  81
  82 static load_balance_t *
  83 load_balance_alloc_i (void)
  84 {
  85     load_balance_t *lb;
  86
  87     pool_get_aligned(load_balance_pool, lb, CLIB_CACHE_LINE_BYTES);
  88     memset(lb, 0, sizeof(*lb));
  89
  90     lb->lb_map = INDEX_INVALID;
  91     lb->lb_urpf = INDEX_INVALID;
  92     vlib_validate_combined_counter(&(load_balance_main.lbm_to_counters),
  93                                    load_balance_get_index(lb));
  94     vlib_validate_combined_counter(&(load_balance_main.lbm_via_counters),
  95                                    load_balance_get_index(lb));
  96     vlib_zero_combined_counter(&(load_balance_main.lbm_to_counters),
  97                                load_balance_get_index(lb));
  98     vlib_zero_combined_counter(&(load_balance_main.lbm_via_counters),
  99                                load_balance_get_index(lb));
 100
 101     return (lb);
 102 }
 103
 104 static u8*
 105 load_balance_format (index_t lbi,
 106                      load_balance_format_flags_t flags,
 107                      u32 indent,
 108                      u8 *s)
 109 {
 110     vlib_counter_t to, via;
 111     load_balance_t *lb;
 112     dpo_id_t *buckets;
 113     u32 i;
 114
 115     lb = load_balance_get(lbi);
 116     vlib_get_combined_counter(&(load_balance_main.lbm_to_counters), lbi, &to);
 117     vlib_get_combined_counter(&(load_balance_main.lbm_via_counters), lbi, &via);
 118     buckets = load_balance_get_buckets(lb);
 119
 120     s = format(s, "%U: ", format_dpo_type, DPO_LOAD_BALANCE);
 121     s = format(s, "[index:%d buckets:%d ", lbi, lb->lb_n_buckets);
 122     s = format(s, "uRPF:%d ", lb->lb_urpf);
 123     s = format(s, "to:[%Ld:%Ld]", to.packets, to.bytes);
 124     if (0 != via.packets)
 125     {
 126         s = format(s, " via:[%Ld:%Ld]",
 127                    via.packets, via.bytes);
 128     }
 129     s = format(s, "]");
 130
 131     if (INDEX_INVALID != lb->lb_map)
 132     {
 133         s = format(s, "\n%U%U",
 134                    format_white_space, indent+4,
 135                    format_load_balance_map, lb->lb_map, indent+4);
 136     }
 137     for (i = 0; i < lb->lb_n_buckets; i++)
 138     {
 139         s = format(s, "\n%U[%d] %U",
 140                    format_white_space, indent+2,
 141                    i,
 142                    format_dpo_id,
 143                    &buckets[i], indent+6);
 144     }
 145     return (s);
 146 }
 147
 148 u8*
 149 format_load_balance (u8 * s, va_list * args)
 150 {
 151     index_t lbi = va_arg(args, index_t);
 152     load_balance_format_flags_t flags = va_arg(args, load_balance_format_flags_t);
 153
 154     return (load_balance_format(lbi, flags, 0, s));
 155 }
 156 static u8*
 157 format_load_balance_dpo (u8 * s, va_list * args)
 158 {
 159     index_t lbi = va_arg(args, index_t);
 160     u32 indent = va_arg(args, u32);
 161
 162     return (load_balance_format(lbi, LOAD_BALANCE_FORMAT_DETAIL, indent, s));
 163 }
 164
 165
 166 static load_balance_t *
 167 load_balance_create_i (u32 num_buckets,
 168                        dpo_proto_t lb_proto,
 169                        flow_hash_config_t fhc)
 170 {
 171     load_balance_t *lb;
 172
 173     lb = load_balance_alloc_i();
 174     lb->lb_hash_config = fhc;
 175     lb->lb_n_buckets = num_buckets;
 176     lb->lb_n_buckets_minus_1 = num_buckets-1;
 177     lb->lb_proto = lb_proto;
 178
 179     if (!LB_HAS_INLINE_BUCKETS(lb))
 180     {
 181         vec_validate_aligned(lb->lb_buckets,
 182                              lb->lb_n_buckets - 1,
 183                              CLIB_CACHE_LINE_BYTES);
 184     }
 185
 186     LB_DBG(lb, "create");
 187
 188     return (lb);
 189 }
 190
 191 index_t
 192 load_balance_create (u32 n_buckets,
 193                      dpo_proto_t lb_proto,
 194                      flow_hash_config_t fhc)
 195 {
 196     return (load_balance_get_index(load_balance_create_i(n_buckets, lb_proto, fhc)));
 197 }
 198
 199 static inline void
 200 load_balance_set_bucket_i (load_balance_t *lb,
 201                            u32 bucket,
 202                            dpo_id_t *buckets,
 203                            const dpo_id_t *next)
 204 {
 205     dpo_stack(DPO_LOAD_BALANCE, lb->lb_proto, &buckets[bucket], next);
 206 }
 207
 208 void
 209 load_balance_set_bucket (index_t lbi,
 210                          u32 bucket,
 211                          const dpo_id_t *next)
 212 {
 213     load_balance_t *lb;
 214     dpo_id_t *buckets;
 215
 216     lb = load_balance_get(lbi);
 217     buckets = load_balance_get_buckets(lb);
 218
 219     ASSERT(bucket < lb->lb_n_buckets);
 220
 221     load_balance_set_bucket_i(lb, bucket, buckets, next);
 222 }
 223
 224 int
 225 load_balance_is_drop (const dpo_id_t *dpo)
 226 {
 227     load_balance_t *lb;
 228
 229     if (DPO_LOAD_BALANCE != dpo->dpoi_type)
 230         return (0);
 231
 232     lb = load_balance_get(dpo->dpoi_index);
 233
 234     if (1 == lb->lb_n_buckets)
 235     {
 236         return (dpo_is_drop(load_balance_get_bucket_i(lb, 0)));
 237     }
 238     return (0);
 239 }
 240
 241 void
 242 load_balance_set_urpf (index_t lbi,
 243                        index_t urpf)
 244 {
 245     load_balance_t *lb;
 246     index_t old;
 247
 248     lb = load_balance_get(lbi);
 249
 250     /*
 251      * packets in flight we see this change. but it's atomic, so :P
 252      */
 253     old = lb->lb_urpf;
 254     lb->lb_urpf = urpf;
 255
 256     fib_urpf_list_unlock(old);
 257     fib_urpf_list_lock(urpf);
 258 }
 259
 260 index_t
 261 load_balance_get_urpf (index_t lbi)
 262 {
 263     load_balance_t *lb;
 264
 265     lb = load_balance_get(lbi);
 266
 267     return (lb->lb_urpf);
 268 }
 269
 270 const dpo_id_t *
 271 load_balance_get_bucket (index_t lbi,
 272                          u32 bucket)
 273 {
 274     load_balance_t *lb;
 275
 276     lb = load_balance_get(lbi);
 277
 278     return (load_balance_get_bucket_i(lb, bucket));
 279 }
 280
 281 static int
 282 next_hop_sort_by_weight (load_balance_path_t * n1,
 283                          load_balance_path_t * n2)
 284 {
 285     return ((int) n1->path_weight - (int) n2->path_weight);
 286 }
 287
 288 /* Given next hop vector is over-written with normalized one with sorted weights and
 289    with weights corresponding to the number of adjacencies for each next hop.
 290    Returns number of adjacencies in block. */
 291 u32
 292 ip_multipath_normalize_next_hops (load_balance_path_t * raw_next_hops,
 293                                   load_balance_path_t ** normalized_next_hops,
 294                                   u32 *sum_weight_in,
 295                                   f64 multipath_next_hop_error_tolerance)
 296 {
 297     load_balance_path_t * nhs;
 298     uword n_nhs, n_adj, n_adj_left, i, sum_weight;
 299     f64 norm, error;
 300
 301     n_nhs = vec_len (raw_next_hops);
 302     ASSERT (n_nhs > 0);
 303     if (n_nhs == 0)
 304         return 0;
 305
 306     /* Allocate enough space for 2 copies; we'll use second copy to save original weights. */
 307     nhs = *normalized_next_hops;
 308     vec_validate (nhs, 2*n_nhs - 1);
 309
 310     /* Fast path: 1 next hop in block. */
 311     n_adj = n_nhs;
 312     if (n_nhs == 1)
 313     {
 314         nhs[0] = raw_next_hops[0];
 315         nhs[0].path_weight = 1;
 316         _vec_len (nhs) = 1;
 317         sum_weight = 1;
 318         goto done;
 319     }
 320
 321     else if (n_nhs == 2)
 322     {
 323         int cmp = next_hop_sort_by_weight (&raw_next_hops[0], &raw_next_hops[1]) < 0;
 324
 325         /* Fast sort. */
 326         nhs[0] = raw_next_hops[cmp];
 327         nhs[1] = raw_next_hops[cmp ^ 1];
 328
 329         /* Fast path: equal cost multipath with 2 next hops. */
 330         if (nhs[0].path_weight == nhs[1].path_weight)
 331         {
 332             nhs[0].path_weight = nhs[1].path_weight = 1;
 333             _vec_len (nhs) = 2;
 334             sum_weight = 2;
 335             goto done;
 336         }
 337     }
 338     else
 339     {
 340         clib_memcpy (nhs, raw_next_hops, n_nhs * sizeof (raw_next_hops[0]));
 341         qsort (nhs, n_nhs, sizeof (nhs[0]), (void *) next_hop_sort_by_weight);
 342     }
 343
 344     /* Find total weight to normalize weights. */
 345     sum_weight = 0;
 346     for (i = 0; i < n_nhs; i++)
 347         sum_weight += nhs[i].path_weight;
 348
 349     /* In the unlikely case that all weights are given as 0, set them all to 1. */
 350     if (sum_weight == 0)
 351     {
 352         for (i = 0; i < n_nhs; i++)
 353             nhs[i].path_weight = 1;
 354         sum_weight = n_nhs;
 355     }
 356
 357     /* Save copies of all next hop weights to avoid being overwritten in loop below. */
 358     for (i = 0; i < n_nhs; i++)
 359         nhs[n_nhs + i].path_weight = nhs[i].path_weight;
 360
 361     /* Try larger and larger power of 2 sized adjacency blocks until we
 362        find one where traffic flows to within 1% of specified weights. */
 363     for (n_adj = max_pow2 (n_nhs); ; n_adj *= 2)
 364     {
 365         error = 0;
 366
 367         norm = n_adj / ((f64) sum_weight);
 368         n_adj_left = n_adj;
 369         for (i = 0; i < n_nhs; i++)
 370         {
 371             f64 nf = nhs[n_nhs + i].path_weight * norm; /* use saved weights */
 372             word n = flt_round_nearest (nf);
 373
 374             n = n > n_adj_left ? n_adj_left : n;
 375             n_adj_left -= n;
 376             error += fabs (nf - n);
 377             nhs[i].path_weight = n;
 378         }
 379
 380         nhs[0].path_weight += n_adj_left;
 381
 382         /* Less than 5% average error per adjacency with this size adjacency block? */
 383         if (error <= multipath_next_hop_error_tolerance*n_adj)
 384         {
 385             /* Truncate any next hops with zero weight. */
 386             _vec_len (nhs) = i;
 387             break;
 388         }
 389     }
 390
 391 done:
 392     /* Save vector for next call. */
 393     *normalized_next_hops = nhs;
 394     *sum_weight_in = sum_weight;
 395     return n_adj;
 396 }
 397
 398 static load_balance_path_t *
 399 load_balance_multipath_next_hop_fixup (load_balance_path_t *nhs,
 400                                        dpo_proto_t drop_proto)
 401 {
 402     if (0 == vec_len(nhs))
 403     {
 404         load_balance_path_t *nh;
 405
 406         /*
 407          * we need something for the load-balance. so use the drop
 408          */
 409         vec_add2(nhs, nh, 1);
 410
 411         nh->path_weight = 1;
 412         dpo_copy(&nh->path_dpo, drop_dpo_get(drop_proto));
 413     }
 414
 415     return (nhs);
 416 }
 417
 418 /*
 419  * Fill in adjacencies in block based on corresponding
 420  * next hop adjacencies.
 421  */
 422 static void
 423 load_balance_fill_buckets (load_balance_t *lb,
 424                            load_balance_path_t *nhs,
 425                            dpo_id_t *buckets,
 426                            u32 n_buckets)
 427 {
 428     load_balance_path_t * nh;
 429     u16 ii, bucket;
 430
 431     bucket = 0;
 432
 433     /*
 434      * the next-hops have normalised weights. that means their sum is the number
 435      * of buckets we need to fill.
 436      */
 437     vec_foreach (nh, nhs)
 438     {
 439         for (ii = 0; ii < nh->path_weight; ii++)
 440         {
 441             ASSERT(bucket < n_buckets);
 442             load_balance_set_bucket_i(lb, bucket++, buckets, &nh->path_dpo);
 443         }
 444     }
 445 }
 446
 447 static inline void
 448 load_balance_set_n_buckets (load_balance_t *lb,
 449                             u32 n_buckets)
 450 {
 451     lb->lb_n_buckets = n_buckets;
 452     lb->lb_n_buckets_minus_1 = n_buckets-1;
 453 }
 454
 455 void
 456 load_balance_multipath_update (const dpo_id_t *dpo,
 457                                load_balance_path_t * raw_next_hops,
 458                                load_balance_flags_t flags)
 459 {
 460     u32 sum_of_weights,n_buckets, ii;
 461     load_balance_path_t * nh, * nhs;
 462     index_t lbmi, old_lbmi;
 463     load_balance_t *lb;
 464     dpo_id_t *tmp_dpo;
 465
 466     nhs = NULL;
 467
 468     ASSERT(DPO_LOAD_BALANCE == dpo->dpoi_type);
 469     lb = load_balance_get(dpo->dpoi_index);
 470     raw_next_hops =
 471         load_balance_multipath_next_hop_fixup(raw_next_hops,
 472                                               lb->lb_proto);
 473     n_buckets =
 474         ip_multipath_normalize_next_hops(raw_next_hops,
 475                                          &nhs,
 476                                          &sum_of_weights,
 477                                          multipath_next_hop_error_tolerance);
 478
 479     ASSERT (n_buckets >= vec_len (raw_next_hops));
 480
 481     /*
 482      * Save the old load-balance map used, and get a new one if required.
 483      */
 484     old_lbmi = lb->lb_map;
 485     if (flags & LOAD_BALANCE_FLAG_USES_MAP)
 486     {
 487         lbmi = load_balance_map_add_or_lock(n_buckets, sum_of_weights, nhs);
 488     }
 489     else
 490     {
 491         lbmi = INDEX_INVALID;
 492     }
 493
 494     if (0 == lb->lb_n_buckets)
 495     {
 496         /*
 497          * first time initialisation. no packets inflight, so we can write
 498          * at leisure.
 499          */
 500         load_balance_set_n_buckets(lb, n_buckets);
 501
 502         if (!LB_HAS_INLINE_BUCKETS(lb))
 503             vec_validate_aligned(lb->lb_buckets,
 504                                  lb->lb_n_buckets - 1,
 505                                  CLIB_CACHE_LINE_BYTES);
 506
 507         load_balance_fill_buckets(lb, nhs,
 508                                   load_balance_get_buckets(lb),
 509                                   n_buckets);
 510         lb->lb_map = lbmi;
 511     }
 512     else
 513     {
 514         /*
 515          * This is a modification of an existing load-balance.
 516          * We need to ensure that packets inflight see a consistent state, that
 517          * is the number of reported buckets the LB has (read from
 518          * lb_n_buckets_minus_1) is not more than it actually has. So if the
 519          * number of buckets is increasing, we must update the bucket array first,
 520          * then the reported number. vice-versa if the number of buckets goes down.
 521          */
 522         if (n_buckets == lb->lb_n_buckets)
 523         {
 524             /*
 525              * no change in the number of buckets. we can simply fill what
 526              * is new over what is old.
 527              */
 528             load_balance_fill_buckets(lb, nhs,
 529                                       load_balance_get_buckets(lb),
 530                                       n_buckets);
 531             lb->lb_map = lbmi;
 532         }
 533         else if (n_buckets > lb->lb_n_buckets)
 534         {
 535             /*
 536              * we have more buckets. the old load-balance map (if there is one)
 537              * will remain valid, i.e. mapping to indices within range, so we
 538              * update it last.
 539              */
 540             if (n_buckets > LB_NUM_INLINE_BUCKETS &&
 541                 lb->lb_n_buckets <= LB_NUM_INLINE_BUCKETS)
 542             {
 543                 /*
 544                  * the new increased number of buckets is crossing the threshold
 545                  * from the inline storage to out-line. Alloc the outline buckets
 546                  * first, then fixup the number. then reset the inlines.
 547                  */
 548                 ASSERT(NULL == lb->lb_buckets);
 549                 vec_validate_aligned(lb->lb_buckets,
 550                                      n_buckets - 1,
 551                                      CLIB_CACHE_LINE_BYTES);
 552
 553                 load_balance_fill_buckets(lb, nhs,
 554                                           lb->lb_buckets,
 555                                           n_buckets);
 556                 CLIB_MEMORY_BARRIER();
 557                 load_balance_set_n_buckets(lb, n_buckets);
 558
 559                 CLIB_MEMORY_BARRIER();
 560
 561                 for (ii = 0; ii < LB_NUM_INLINE_BUCKETS; ii++)
 562                 {
 563                     dpo_reset(&lb->lb_buckets_inline[ii]);
 564                 }
 565             }
 566             else
 567             {
 568                 /*
 569                  * we are not crossing the threshold. we can write the new on the
 570                  * old, whether they be inline or not.
 571                  */
 572                 load_balance_fill_buckets(lb, nhs,
 573                                           load_balance_get_buckets(lb),
 574                                           n_buckets);
 575                 CLIB_MEMORY_BARRIER();
 576                 load_balance_set_n_buckets(lb, n_buckets);
 577             }
 578
 579             /*
 580              * buckets fixed. ready for the MAP update.
 581              */
 582             lb->lb_map = lbmi;
 583         }
 584         else
 585         {
 586             /*
 587              * bucket size shrinkage.
 588              * Any map we have will be based on the old
 589              * larger number of buckets, so will be translating to indices
 590              * out of range. So the new MAP must be installed first.
 591              */
 592             lb->lb_map = lbmi;
 593             CLIB_MEMORY_BARRIER();
 594
 595
 596             if (n_buckets <= LB_NUM_INLINE_BUCKETS &&
 597                 lb->lb_n_buckets > LB_NUM_INLINE_BUCKETS)
 598             {
 599                 /*
 600                  * the new decreased number of buckets is crossing the threshold
 601                  * from out-line storage to inline:
 602                  *   1 - Fill the inline buckets,
 603                  *   2 - fixup the number (and this point the inline buckets are
 604                  *       used).
 605                  *   3 - free the outline buckets
 606                  */
 607                 load_balance_fill_buckets(lb, nhs,
 608                                           lb->lb_buckets_inline,
 609                                           n_buckets);
 610                 CLIB_MEMORY_BARRIER();
 611                 load_balance_set_n_buckets(lb, n_buckets);
 612                 CLIB_MEMORY_BARRIER();
 613
 614                 vec_foreach(tmp_dpo, lb->lb_buckets)
 615                 {
 616                     dpo_reset(tmp_dpo);
 617                 }
 618                 vec_free(lb->lb_buckets);
 619             }
 620             else
 621             {
 622                 /*
 623                  * not crossing the threshold.
 624                  *  1 - update the number to the smaller size
 625                  *  2 - write the new buckets
 626                  *  3 - reset those no longer used.
 627                  */
 628                 dpo_id_t *buckets;
 629                 u32 old_n_buckets;
 630
 631                 old_n_buckets = lb->lb_n_buckets;
 632                 buckets = load_balance_get_buckets(lb);
 633
 634                 load_balance_set_n_buckets(lb, n_buckets);
 635                 CLIB_MEMORY_BARRIER();
 636
 637                 load_balance_fill_buckets(lb, nhs,
 638                                           buckets,
 639                                           n_buckets);
 640
 641                 for (ii = old_n_buckets-n_buckets; ii < old_n_buckets; ii++)
 642                 {
 643                     dpo_reset(&buckets[ii]);
 644                 }
 645             }
 646         }
 647     }
 648
 649     vec_foreach (nh, nhs)
 650     {
 651         dpo_reset(&nh->path_dpo);
 652     }
 653     vec_free(nhs);
 654
 655     load_balance_map_unlock(old_lbmi);
 656 }
 657
 658 static void
 659 load_balance_lock (dpo_id_t *dpo)
 660 {
 661     load_balance_t *lb;
 662
 663     lb = load_balance_get(dpo->dpoi_index);
 664
 665     lb->lb_locks++;
 666 }
 667
 668 static void
 669 load_balance_destroy (load_balance_t *lb)
 670 {
 671     dpo_id_t *buckets;
 672     int i;
 673
 674     buckets = load_balance_get_buckets(lb);
 675
 676     for (i = 0; i < lb->lb_n_buckets; i++)
 677     {
 678         dpo_reset(&buckets[i]);
 679     }
 680
 681     LB_DBG(lb, "destroy");
 682     if (!LB_HAS_INLINE_BUCKETS(lb))
 683     {
 684         vec_free(lb->lb_buckets);
 685     }
 686
 687     fib_urpf_list_unlock(lb->lb_urpf);
 688     load_balance_map_unlock(lb->lb_map);
 689
 690     pool_put(load_balance_pool, lb);
 691 }
 692
 693 static void
 694 load_balance_unlock (dpo_id_t *dpo)
 695 {
 696     load_balance_t *lb;
 697
 698     lb = load_balance_get(dpo->dpoi_index);
 699
 700     lb->lb_locks--;
 701
 702     if (0 == lb->lb_locks)
 703     {
 704         load_balance_destroy(lb);
 705     }
 706 }
 707
 708 static void
 709 load_balance_mem_show (void)
 710 {
 711     fib_show_memory_usage("load-balance",
 712                           pool_elts(load_balance_pool),
 713                           pool_len(load_balance_pool),
 714                           sizeof(load_balance_t));
 715     load_balance_map_show_mem();
 716 }
 717
 718 const static dpo_vft_t lb_vft = {
 719     .dv_lock = load_balance_lock,
 720     .dv_unlock = load_balance_unlock,
 721     .dv_format = format_load_balance_dpo,
 722     .dv_mem_show = load_balance_mem_show,
 723 };
 724
 725 /**
 726  * @brief The per-protocol VLIB graph nodes that are assigned to a load-balance
 727  *        object.
 728  *
 729  * this means that these graph nodes are ones from which a load-balance is the
 730  * parent object in the DPO-graph.
 731  *
 732  * We do not list all the load-balance nodes, such as the *-lookup. instead
 733  * we are relying on the correct use of the .sibling_of field when setting
 734  * up these sibling nodes.
 735  */
 736 const static char* const load_balance_ip4_nodes[] =
 737 {
 738     "ip4-load-balance",
 739     NULL,
 740 };
 741 const static char* const load_balance_ip6_nodes[] =
 742 {
 743     "ip6-load-balance",
 744     NULL,
 745 };
 746 const static char* const load_balance_mpls_nodes[] =
 747 {
 748     "mpls-load-balance",
 749     NULL,
 750 };
 751 const static char* const load_balance_l2_nodes[] =
 752 {
 753     "l2-load-balance",
 754     NULL,
 755 };
 756 const static char* const * const load_balance_nodes[DPO_PROTO_NUM] =
 757 {
 758     [DPO_PROTO_IP4]  = load_balance_ip4_nodes,
 759     [DPO_PROTO_IP6]  = load_balance_ip6_nodes,
 760     [DPO_PROTO_MPLS] = load_balance_mpls_nodes,
 761     [DPO_PROTO_ETHERNET] = load_balance_l2_nodes,
 762 };
 763
 764 void
 765 load_balance_module_init (void)
 766 {
 767     dpo_register(DPO_LOAD_BALANCE, &lb_vft, load_balance_nodes);
 768
 769     load_balance_map_module_init();
 770 }
 771
 772 static clib_error_t *
 773 load_balance_show (vlib_main_t * vm,
 774                    unformat_input_t * input,
 775                    vlib_cli_command_t * cmd)
 776 {
 777     index_t lbi = INDEX_INVALID;
 778
 779     while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 780     {
 781         if (unformat (input, "%d", &lbi))
 782             ;
 783         else
 784             break;
 785     }
 786
 787     if (INDEX_INVALID != lbi)
 788     {
 789         vlib_cli_output (vm, "%U", format_load_balance, lbi,
 790                          LOAD_BALANCE_FORMAT_DETAIL);
 791     }
 792     else
 793     {
 794         load_balance_t *lb;
 795
 796         pool_foreach(lb, load_balance_pool,
 797         ({
 798             vlib_cli_output (vm, "%U", format_load_balance,
 799                              load_balance_get_index(lb),
 800                              LOAD_BALANCE_FORMAT_NONE);
 801         }));
 802     }
 803
 804     return 0;
 805 }
 806
 807 VLIB_CLI_COMMAND (load_balance_show_command, static) = {
 808     .path = "show load-balance",
 809     .short_help = "show load-balance [<index>]",
 810     .function = load_balance_show,
 811 };
 812
 813
 814 always_inline u32
 815 ip_flow_hash (void *data)
 816 {
 817   ip4_header_t *iph = (ip4_header_t *) data;
 818
 819   if ((iph->ip_version_and_header_length & 0xF0) == 0x40)
 820     return ip4_compute_flow_hash (iph, IP_FLOW_HASH_DEFAULT);
 821   else
 822     return ip6_compute_flow_hash ((ip6_header_t *) iph, IP_FLOW_HASH_DEFAULT);
 823 }
 824
 825 always_inline u64
 826 mac_to_u64 (u8 * m)
 827 {
 828   return (*((u64 *) m) & 0xffffffffffff);
 829 }
 830
 831 always_inline u32
 832 l2_flow_hash (vlib_buffer_t * b0)
 833 {
 834   ethernet_header_t *eh;
 835   u64 a, b, c;
 836   uword is_ip, eh_size;
 837   u16 eh_type;
 838
 839   eh = vlib_buffer_get_current (b0);
 840   eh_type = clib_net_to_host_u16 (eh->type);
 841   eh_size = ethernet_buffer_header_size (b0);
 842
 843   is_ip = (eh_type == ETHERNET_TYPE_IP4 || eh_type == ETHERNET_TYPE_IP6);
 844
 845   /* since we have 2 cache lines, use them */
 846   if (is_ip)
 847     a = ip_flow_hash ((u8 *) vlib_buffer_get_current (b0) + eh_size);
 848   else
 849     a = eh->type;
 850
 851   b = mac_to_u64 ((u8 *) eh->dst_address);
 852   c = mac_to_u64 ((u8 *) eh->src_address);
 853   hash_mix64 (a, b, c);
 854
 855   return (u32) c;
 856 }
 857
 858 typedef struct load_balance_trace_t_
 859 {
 860     index_t lb_index;
 861 } load_balance_trace_t;
 862
 863 static uword
 864 l2_load_balance (vlib_main_t * vm,
 865                  vlib_node_runtime_t * node,
 866                  vlib_frame_t * frame)
 867 {
 868   u32 n_left_from, next_index, *from, *to_next;
 869
 870   from = vlib_frame_vector_args (frame);
 871   n_left_from = frame->n_vectors;
 872
 873   next_index = node->cached_next_index;
 874
 875   while (n_left_from > 0)
 876     {
 877       u32 n_left_to_next;
 878
 879       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 880
 881       while (n_left_from > 0 && n_left_to_next > 0)
 882         {
 883           vlib_buffer_t *b0;
 884           u32 bi0, lbi0, next0;
 885           const dpo_id_t *dpo0;
 886           const load_balance_t *lb0;
 887
 888           bi0 = from[0];
 889           to_next[0] = bi0;
 890           from += 1;
 891           to_next += 1;
 892           n_left_from -= 1;
 893           n_left_to_next -= 1;
 894
 895           b0 = vlib_get_buffer (vm, bi0);
 896
 897           /* lookup dst + src mac */
 898           lbi0 =  vnet_buffer (b0)->ip.adj_index[VLIB_TX];
 899           lb0 = load_balance_get(lbi0);
 900
 901           vnet_buffer(b0)->ip.flow_hash = l2_flow_hash(b0);
 902
 903           dpo0 = load_balance_get_bucket_i(lb0,
 904                                            vnet_buffer(b0)->ip.flow_hash &
 905                                            (lb0->lb_n_buckets_minus_1));
 906
 907           next0 = dpo0->dpoi_next_node;
 908           vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
 909
 910           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 911             {
 912               load_balance_trace_t *tr = vlib_add_trace (vm, node, b0,
 913                                                          sizeof (*tr));
 914               tr->lb_index = lbi0;
 915             }
 916           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 917                                            n_left_to_next, bi0, next0);
 918         }
 919
 920       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 921     }
 922
 923   return frame->n_vectors;
 924 }
 925
 926 static u8 *
 927 format_load_balance_trace (u8 * s, va_list * args)
 928 {
 929   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 930   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 931   load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *);
 932
 933   s = format (s, "L2-load-balance: index %d", t->lb_index);
 934   return s;
 935 }
 936
 937 /**
 938  * @brief
 939  */
 940 VLIB_REGISTER_NODE (l2_load_balance_node) = {
 941   .function = l2_load_balance,
 942   .name = "l2-load-balance",
 943   .vector_size = sizeof (u32),
 944
 945   .format_trace = format_load_balance_trace,
 946   .n_next_nodes = 1,
 947   .next_nodes = {
 948       [0] = "error-drop",
 949   },
 950 };