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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 #include <vnet/fib/fib_path.h>
19 #include <vnet/fib/fib_node_list.h>
20 #include <vnet/dpo/load_balance_map.h>
21 #include <vnet/dpo/load_balance.h>
24 * A hash-table of load-balance maps by path index.
25 * this provides the fast lookup of the LB map when a path goes down
27 static uword *lb_maps_by_path_index;
30 * A hash-table of load-balance maps by set of paths.
31 * This provides the LB map sharing.
32 * LB maps do not necessarily use all the paths in the list, since
33 * the entry that is requesting the map, may not have an out-going
34 * label for each of the paths.
36 static uword *load_balance_map_db;
38 typedef enum load_balance_map_path_flags_t_
40 LOAD_BALANCE_MAP_PATH_UP = (1 << 0),
41 LOAD_BALANCE_MAP_PATH_USABLE = (1 << 1),
42 } __attribute__ ((packed)) load_balance_map_path_flags_t;
44 typedef struct load_balance_map_path_t_ {
48 fib_node_index_t lbmp_index;
51 * Sibling Index in the list of all maps with this path index
53 fib_node_index_t lbmp_sibling;
56 * the normalised wegiht of the path
61 * The sate of the path
63 load_balance_map_path_flags_t lbmp_flags;
64 } load_balance_map_path_t;
67 * The global pool of LB maps
69 load_balance_map_t *load_balance_map_pool;
75 #define LOAD_BALANCE_MAP_DBG(_pl, _fmt, _args...) \
77 clib_warning("lbm: FIXME" _fmt, \
81 #define LOAD_BALANCE_MAP_DBG(_pl, _fmt, _args...)
85 load_balance_map_get_index (load_balance_map_t *lbm)
87 return (lbm - load_balance_map_pool);
91 format_load_balance_map (u8 *s, va_list ap)
93 index_t lbmi = va_arg(ap, index_t);
94 u32 indent = va_arg(ap, u32);
95 load_balance_map_t *lbm;
98 lbm = load_balance_map_get(lbmi);
99 n_buckets = vec_len(lbm->lbm_buckets);
101 s = format(s, "load-balance-map: index:%d buckets:%d", lbmi, n_buckets);
102 s = format(s, "\n%U index:", format_white_space, indent+2);
103 for (ii = 0; ii < n_buckets; ii++)
105 s = format(s, "%5d", ii);
107 s = format(s, "\n%U map:", format_white_space, indent+2);
108 for (ii = 0; ii < n_buckets; ii++)
110 s = format(s, "%5d", lbm->lbm_buckets[ii]);
118 load_balance_map_hash (load_balance_map_t *lbm)
120 u32 old_lbm_hash, new_lbm_hash, hash;
121 load_balance_map_path_t *lb_path;
123 new_lbm_hash = old_lbm_hash = vec_len(lbm->lbm_paths);
125 vec_foreach (lb_path, lbm->lbm_paths)
127 hash = lb_path->lbmp_index;
128 hash_mix32(hash, old_lbm_hash, new_lbm_hash);
131 return (new_lbm_hash);
135 load_balance_map_db_hash_key_from_index (uword index)
141 load_balance_map_db_hash_key_is_index (uword key)
147 load_balance_map_db_hash_key_2_index (uword key)
149 ASSERT (load_balance_map_db_hash_key_is_index (key));
153 static load_balance_map_t*
154 load_balance_map_db_get_from_hash_key (uword key)
156 load_balance_map_t *lbm;
158 if (load_balance_map_db_hash_key_is_index (key))
162 lbm_index = load_balance_map_db_hash_key_2_index(key);
163 lbm = load_balance_map_get(lbm_index);
167 lbm = uword_to_pointer (key, load_balance_map_t *);
174 load_balance_map_db_hash_key_sum (hash_t * h,
177 load_balance_map_t *lbm;
179 lbm = load_balance_map_db_get_from_hash_key(key);
181 return (load_balance_map_hash(lbm));
185 load_balance_map_db_hash_key_equal (hash_t * h,
189 load_balance_map_t *lbm1, *lbm2;
191 lbm1 = load_balance_map_db_get_from_hash_key(key1);
192 lbm2 = load_balance_map_db_get_from_hash_key(key2);
194 return (load_balance_map_hash(lbm1) ==
195 load_balance_map_hash(lbm2));
199 load_balance_map_db_find (load_balance_map_t *lbm)
203 p = hash_get(load_balance_map_db, lbm);
210 return (FIB_NODE_INDEX_INVALID);
214 load_balance_map_db_insert (load_balance_map_t *lbm)
216 load_balance_map_path_t *lbmp;
217 fib_node_list_t list;
220 ASSERT(FIB_NODE_INDEX_INVALID == load_balance_map_db_find(lbm));
223 * insert into the DB based on the set of paths.
225 hash_set (load_balance_map_db,
226 load_balance_map_db_hash_key_from_index(
227 load_balance_map_get_index(lbm)),
228 load_balance_map_get_index(lbm));
231 * insert into each per-path list.
233 vec_foreach(lbmp, lbm->lbm_paths)
235 p = hash_get(lb_maps_by_path_index, lbmp->lbmp_index);
239 list = fib_node_list_create();
240 hash_set(lb_maps_by_path_index, lbmp->lbmp_index, list);
248 fib_node_list_push_front(list,
249 0, FIB_NODE_TYPE_FIRST,
250 load_balance_map_get_index(lbm));
253 LOAD_BALANCE_MAP_DBG(lbm, "DB-inserted");
257 load_balance_map_db_remove (load_balance_map_t *lbm)
259 load_balance_map_path_t *lbmp;
262 ASSERT(FIB_NODE_INDEX_INVALID != load_balance_map_db_find(lbm));
264 hash_unset(load_balance_map_db,
265 load_balance_map_db_hash_key_from_index(
266 load_balance_map_get_index(lbm)));
269 * remove from each per-path list.
271 vec_foreach(lbmp, lbm->lbm_paths)
273 p = hash_get(lb_maps_by_path_index, lbmp->lbmp_index);
277 fib_node_list_remove(p[0], lbmp->lbmp_sibling);
280 LOAD_BALANCE_MAP_DBG(lbm, "DB-removed");
284 * @brief from the paths that are usable, fill the Map.
287 load_balance_map_fill (load_balance_map_t *lbm)
289 load_balance_map_path_t *lbmp;
290 u32 n_buckets, bucket, ii, jj;
294 n_buckets = vec_len(lbm->lbm_buckets);
297 * run throught the set of paths once, and build a vector of the
298 * indices that are usable. we do this is a scratch space, since we
299 * need to refer to it multiple times as we build the real buckets.
301 vec_validate(tmp_buckets, n_buckets-1);
304 vec_foreach (lbmp, lbm->lbm_paths)
306 if (fib_path_is_resolved(lbmp->lbmp_index))
308 for (ii = 0; ii < lbmp->lbmp_weight; ii++)
310 tmp_buckets[jj++] = bucket++;
315 bucket += lbmp->lbmp_weight;
318 _vec_len(tmp_buckets) = jj;
321 * If the number of temporaries written is as many as we need, implying
322 * all paths were up, then we can simply copy the scratch area over the
323 * actual buckets' memory
327 memcpy(lbm->lbm_buckets,
329 sizeof(lbm->lbm_buckets[0]) * n_buckets);
334 * one or more paths are down.
336 if (0 == vec_len(tmp_buckets))
339 * if the scratch area is empty, then no paths are usable.
340 * they will all drop. so use them all, lest we account drops
343 for (bucket = 0; bucket < n_buckets; bucket++)
345 lbm->lbm_buckets[bucket] = bucket;
351 vec_foreach (lbmp, lbm->lbm_paths)
353 if (fib_path_is_resolved(lbmp->lbmp_index))
355 for (ii = 0; ii < lbmp->lbmp_weight; ii++)
357 lbm->lbm_buckets[bucket] = bucket;
365 * cycle through the scratch space selecting a index.
366 * this means we load balance, in the intended ratio,
367 * over the paths that are still usable.
369 for (ii = 0; ii < lbmp->lbmp_weight; ii++)
371 lbm->lbm_buckets[bucket] = tmp_buckets[jj];
372 jj = (jj + 1) % vec_len(tmp_buckets);
380 vec_free(tmp_buckets);
383 static load_balance_map_t*
384 load_balance_map_alloc (const load_balance_path_t *paths)
386 load_balance_map_t *lbm;
389 pool_get_aligned(load_balance_map_pool, lbm, CLIB_CACHE_LINE_BYTES);
390 memset(lbm, 0, sizeof(*lbm));
392 vec_validate(lbm->lbm_paths, vec_len(paths)-1);
394 vec_foreach_index(ii, paths)
396 lbm->lbm_paths[ii].lbmp_index = paths[ii].path_index;
397 lbm->lbm_paths[ii].lbmp_weight = paths[ii].path_weight;
403 static load_balance_map_t *
404 load_balance_map_init (load_balance_map_t *lbm,
408 lbm->lbm_sum_of_norm_weights = sum_of_weights;
409 vec_validate(lbm->lbm_buckets, n_buckets-1);
411 load_balance_map_db_insert(lbm);
413 load_balance_map_fill(lbm);
419 load_balance_map_add_or_lock (u32 n_buckets,
421 const load_balance_path_t *paths)
423 load_balance_map_t *tmp, *lbm;
426 tmp = load_balance_map_alloc(paths);
428 lbmi = load_balance_map_db_find(tmp);
430 if (INDEX_INVALID == lbmi)
432 lbm = load_balance_map_init(tmp, n_buckets, sum_of_weights);
436 lbm = load_balance_map_get(lbmi);
441 return (load_balance_map_get_index(lbm));
445 load_balance_map_lock (index_t lbmi)
447 load_balance_map_t *lbm;
449 lbm = load_balance_map_get(lbmi);
455 load_balance_map_unlock (index_t lbmi)
457 load_balance_map_t *lbm;
459 if (INDEX_INVALID == lbmi)
464 lbm = load_balance_map_get(lbmi);
468 if (0 == lbm->lbm_locks)
470 load_balance_map_db_remove(lbm);
471 vec_free(lbm->lbm_paths);
472 vec_free(lbm->lbm_buckets);
473 pool_put(load_balance_map_pool, lbm);
478 load_balance_map_path_state_change_walk (fib_node_ptr_t *fptr,
481 load_balance_map_t *lbm;
483 lbm = load_balance_map_get(fptr->fnp_index);
485 load_balance_map_fill(lbm);
491 * @brief the state of a path has changed (it has no doubt gone down).
492 * This is the trigger to perform a PIC edge cutover and update the maps
493 * to exclude this path.
496 load_balance_map_path_state_change (fib_node_index_t path_index)
501 * re-stripe the buckets for each affect MAP
503 p = hash_get(lb_maps_by_path_index, path_index);
508 fib_node_list_walk(p[0], load_balance_map_path_state_change_walk, NULL);
512 * @brief Make/add a new or lock an existing Load-balance map
515 load_balance_map_module_init (void)
517 load_balance_map_db =
518 hash_create2 (/* elts */ 0,
520 /* value_bytes */ sizeof (index_t),
521 load_balance_map_db_hash_key_sum,
522 load_balance_map_db_hash_key_equal,
523 /* format pair/arg */
526 lb_maps_by_path_index = hash_create(0, sizeof(fib_node_list_t));
529 static clib_error_t *
530 load_balance_map_show (vlib_main_t * vm,
531 unformat_input_t * input,
532 vlib_cli_command_t * cmd)
534 index_t lbmi = INDEX_INVALID;
536 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
538 if (unformat (input, "%d", &lbmi))
544 if (INDEX_INVALID != lbmi)
546 vlib_cli_output (vm, "%U", format_load_balance_map, lbmi, 0);
550 load_balance_map_t *lbm;
552 pool_foreach(lbm, load_balance_map_pool,
554 vlib_cli_output (vm, "%U", format_load_balance_map,
555 load_balance_map_get_index(lbm), 0);
562 VLIB_CLI_COMMAND (load_balance_map_show_command, static) = {
563 .path = "show load-balance-map",
564 .short_help = "show load-balance-map [<index>]",
565 .function = load_balance_map_show,