/* * Copyright (c) 2016 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <vnet/dpo/load_balance.h> #include <vnet/dpo/load_balance_map.h> #include <vnet/dpo/drop_dpo.h> #include <vppinfra/math.h> /* for fabs */ #include <vnet/adj/adj.h> #include <vnet/adj/adj_internal.h> #include <vnet/fib/fib_urpf_list.h> #include <vnet/bier/bier_fwd.h> #include <vnet/fib/mpls_fib.h> #include <vnet/ip/ip4_inlines.h> #include <vnet/ip/ip6_inlines.h> // clang-format off /* * distribution error tolerance for load-balancing */ const f64 multipath_next_hop_error_tolerance = 0.1; static const char *load_balance_attr_names[] = LOAD_BALANCE_ATTR_NAMES; /** * the logger */ vlib_log_class_t load_balance_logger; #define LB_DBG(_lb, _fmt, _args...) \ { \ vlib_log_debug(load_balance_logger, \ "lb:[%U]:" _fmt, \ format_load_balance, load_balance_get_index(_lb), \ LOAD_BALANCE_FORMAT_NONE, \ ##_args); \ } /** * Pool of all DPOs. It's not static so the DP can have fast access */ load_balance_t *load_balance_pool; /** * The one instance of load-balance main */ load_balance_main_t load_balance_main = { .lbm_to_counters = { .name = "route-to", .stat_segment_name = "/net/route/to", }, .lbm_via_counters = { .name = "route-via", .stat_segment_name = "/net/route/via", } }; f64 load_balance_get_multipath_tolerance (void) { return (multipath_next_hop_error_tolerance); } static inline index_t load_balance_get_index (const load_balance_t *lb) { return (lb - load_balance_pool); } static inline dpo_id_t* load_balance_get_buckets (load_balance_t *lb) { if (LB_HAS_INLINE_BUCKETS(lb)) { return (lb->lb_buckets_inline); } else { return (lb->lb_buckets); } } static load_balance_t * load_balance_alloc_i (void) { load_balance_t *lb; u8 need_barrier_sync = 0; vlib_main_t *vm = vlib_get_main(); ASSERT (vm->thread_index == 0); pool_get_aligned_will_expand (load_balance_pool, need_barrier_sync, CLIB_CACHE_LINE_BYTES); if (need_barrier_sync) vlib_worker_thread_barrier_sync (vm); pool_get_aligned(load_balance_pool, lb, CLIB_CACHE_LINE_BYTES); clib_memset(lb, 0, sizeof(*lb)); lb->lb_map = INDEX_INVALID; lb->lb_urpf = INDEX_INVALID; if (need_barrier_sync == 0) { need_barrier_sync += vlib_validate_combined_counter_will_expand (&(load_balance_main.lbm_to_counters), load_balance_get_index(lb)); need_barrier_sync += vlib_validate_combined_counter_will_expand (&(load_balance_main.lbm_via_counters), load_balance_get_index(lb)); if (need_barrier_sync) vlib_worker_thread_barrier_sync (vm); } vlib_validate_combined_counter(&(load_balance_main.lbm_to_counters), load_balance_get_index(lb)); vlib_validate_combined_counter(&(load_balance_main.lbm_via_counters), load_balance_get_index(lb)); vlib_zero_combined_counter(&(load_balance_main.lbm_to_counters), load_balance_get_index(lb)); vlib_zero_combined_counter(&(load_balance_main.lbm_via_counters), load_balance_get_index(lb)); if (need_barrier_sync) vlib_worker_thread_barrier_release (vm); return (lb); } static u8* load_balance_format (index_t lbi, load_balance_format_flags_t flags, u32 indent, u8 *s) { vlib_counter_t to, via; load_balance_t *lb; dpo_id_t *buckets; u32 i; lb = load_balance_get(lbi); vlib_get_combined_counter(&(load_balance_main.lbm_to_counters), lbi, &to); vlib_get_combined_counter(&(load_balance_main.lbm_via_counters), lbi, &via); buckets = load_balance_get_buckets(lb); s = format(s, "%U: ", format_dpo_type, DPO_LOAD_BALANCE); s = format(s, "[proto:%U ", format_dpo_proto, lb->lb_proto); s = format(s, "index:%d buckets:%d ", lbi, lb->lb_n_buckets); s = format(s, "uRPF:%d ", lb->lb_urpf); if (lb->lb_flags) { load_balance_attr_t attr; s = format(s, "flags:["); FOR_EACH_LOAD_BALANCE_ATTR(attr) { if (lb->lb_flags & (1 << attr)) { s = format (s, "%s", load_balance_attr_names[attr]); } } s = format(s, "] "); } s = format(s, "to:[%Ld:%Ld]", to.packets, to.bytes); if (0 != via.packets) { s = format(s, " via:[%Ld:%Ld]", via.packets, via.bytes); } s = format(s, "]"); if (INDEX_INVALID != lb->lb_map) { s = format(s, "\n%U%U", format_white_space, indent+4, format_load_balance_map, lb->lb_map, indent+4); } for (i = 0; i < lb->lb_n_buckets; i++) { s = format(s, "\n%U[%d] %U", format_white_space, indent+2, i, format_dpo_id, &buckets[i], indent+6); } return (s); } u8* format_load_balance (u8 * s, va_list * args) { index_t lbi = va_arg(*args, index_t); load_balance_format_flags_t flags = va_arg(*args, load_balance_format_flags_t); return (load_balance_format(lbi, flags, 0, s)); } static u8* format_load_balance_dpo (u8 * s, va_list * args) { index_t lbi = va_arg(*args, index_t); u32 indent = va_arg(*args, u32); return (load_balance_format(lbi, LOAD_BALANCE_FORMAT_DETAIL, indent, s)); } flow_hash_config_t load_balance_get_default_flow_hash (dpo_proto_t lb_proto) { switch (lb_proto) { case DPO_PROTO_IP4: case DPO_PROTO_IP6: return (IP_FLOW_HASH_DEFAULT); case DPO_PROTO_MPLS: return (MPLS_FLOW_HASH_DEFAULT); case DPO_PROTO_ETHERNET: case DPO_PROTO_BIER: case DPO_PROTO_NSH: break; } return (0); } static load_balance_t * load_balance_create_i (u32 num_buckets, dpo_proto_t lb_proto, flow_hash_config_t fhc) { load_balance_t *lb; lb = load_balance_alloc_i(); lb->lb_hash_config = fhc; lb->lb_n_buckets = num_buckets; lb->lb_n_buckets_minus_1 = num_buckets-1; lb->lb_proto = lb_proto; if (!LB_HAS_INLINE_BUCKETS(lb)) { vec_validate_aligned(lb->lb_buckets, lb->lb_n_buckets - 1, CLIB_CACHE_LINE_BYTES); } LB_DBG(lb, "create"); return (lb); } index_t load_balance_create (u32 n_buckets, dpo_proto_t lb_proto, flow_hash_config_t fhc) { return (load_balance_get_index(load_balance_create_i(n_buckets, lb_proto, fhc))); } static inline void load_balance_set_bucket_i (load_balance_t *lb, u32 bucket, dpo_id_t *buckets, const dpo_id_t *next) { dpo_stack(DPO_LOAD_BALANCE, lb->lb_proto, &buckets[bucket], next); } void load_balance_set_bucket (index_t lbi, u32 bucket, const dpo_id_t *next) { load_balance_t *lb; dpo_id_t *buckets; lb = load_balance_get(lbi); buckets = load_balance_get_buckets(lb); ASSERT(bucket < lb->lb_n_buckets); load_balance_set_bucket_i(lb, bucket, buckets, next); } int load_balance_is_drop (const dpo_id_t *dpo) { load_balance_t *lb; if (DPO_LOAD_BALANCE != dpo->dpoi_type) return (0); lb = load_balance_get(dpo->dpoi_index); if (1 == lb->lb_n_buckets) { return (dpo_is_drop(load_balance_get_bucket_i(lb, 0))); } return (0); } u16 load_balance_n_buckets (index_t lbi) { load_balance_t *lb; lb = load_balance_get(lbi); return (lb->lb_n_buckets); } void load_balance_set_fib_entry_flags (index_t lbi, fib_entry_flag_t flags) { load_balance_t *lb; lb = load_balance_get(lbi); lb->lb_fib_entry_flags = flags; } void load_balance_set_urpf (index_t lbi, index_t urpf) { load_balance_t *lb; index_t old; lb = load_balance_get(lbi); /* * packets in flight we see this change. but it's atomic, so :P */ old = lb->lb_urpf; lb->lb_urpf = urpf; fib_urpf_list_unlock(old); fib_urpf_list_lock(urpf); } index_t load_balance_get_urpf (index_t lbi) { load_balance_t *lb; lb = load_balance_get(lbi); return (lb->lb_urpf); } const dpo_id_t * load_balance_get_bucket (index_t lbi, u32 bucket) { load_balance_t *lb; lb = load_balance_get(lbi); return (load_balance_get_bucket_i(lb, bucket)); } static int next_hop_sort_by_weight (const load_balance_path_t * n1, const load_balance_path_t * n2) { return ((int) n1->path_weight - (int) n2->path_weight); } /* Given next hop vector is over-written with normalized one with sorted weights and with weights corresponding to the number of adjacencies for each next hop. Returns number of adjacencies in block. */ u32 ip_multipath_normalize_next_hops (const load_balance_path_t * raw_next_hops, load_balance_path_t ** normalized_next_hops, u32 *sum_weight_in, f64 multipath_next_hop_error_tolerance) { load_balance_path_t * nhs; uword n_nhs, n_adj, n_adj_left, i, sum_weight; f64 norm, error; n_nhs = vec_len (raw_next_hops); ASSERT (n_nhs > 0); if (n_nhs == 0) return 0; /* Allocate enough space for 2 copies; we'll use second copy to save original weights. */ nhs = *normalized_next_hops; vec_validate (nhs, 2*n_nhs - 1); /* Fast path: 1 next hop in block. */ n_adj = n_nhs; if (n_nhs == 1) { nhs[0] = raw_next_hops[0]; nhs[0].path_weight = 1; _vec_len (nhs) = 1; sum_weight = 1; goto done; } else if (n_nhs == 2) { int cmp = next_hop_sort_by_weight (&raw_next_hops[0], &raw_next_hops[1]) < 0; /* Fast sort. */ nhs[0] = raw_next_hops[cmp]; nhs[1] = raw_next_hops[cmp ^ 1]; /* Fast path: equal cost multipath with 2 next hops. */ if (nhs[0].path_weight == nhs[1].path_weight) { nhs[0].path_weight = nhs[1].path_weight = 1; _vec_len (nhs) = 2; sum_weight = 2; goto done; } } else { clib_memcpy_fast (nhs, raw_next_hops, n_nhs * sizeof (raw_next_hops[0])); qsort (nhs, n_nhs, sizeof (nhs[0]), (void *) next_hop_sort_by_weight); } /* Find total weight to normalize weights. */ sum_weight = 0; for (i = 0; i < n_nhs; i++) sum_weight += nhs[i].path_weight; /* In the unlikely case that all weights are given as 0, set them all to 1. */ if (sum_weight == 0) { for (i = 0; i < n_nhs; i++) nhs[i].path_weight = 1; sum_weight = n_nhs; } /* Save copies of all next hop weights to avoid being overwritten in loop below. */ for (i = 0; i < n_nhs; i++) nhs[n_nhs + i].path_weight = nhs[i].path_weight; /* Try larger and larger power of 2 sized adjacency blocks until we find one where traffic flows to within 1% of specified weights. */ for (n_adj = max_pow2 (n_nhs); ; n_adj *= 2) { error = 0; norm = n_adj / ((f64) sum_weight); n_adj_left = n_adj; for (i = 0; i < n_nhs; i++) { f64 nf = nhs[n_nhs + i].path_weight * norm; /* use saved weights */ word n = flt_round_nearest (nf); n = n > n_adj_left ? n_adj_left : n; n_adj_left -= n; error += fabs (nf - n); nhs[i].path_weight = n; if (0 == nhs[i].path_weight) { /* * when the weight skew is high (norm is small) and n == nf. * without this correction the path with a low weight would have * no representation in the load-balanace - don't want that. * If the weight skew is high so the load-balance has many buckets * to allow it. pays ya money takes ya choice. */ error = n_adj; break; } } nhs[0].path_weight += n_adj_left; /* Less than 5% average error per adjacency with this size adjacency block? */ if (error <= multipath_next_hop_error_tolerance*n_adj) { /* Truncate any next hops with zero weight. */ _vec_len (nhs) = i; break; } } done: /* Save vector for next call. */ *normalized_next_hops = nhs; *sum_weight_in = sum_weight; return n_adj; } static load_balance_path_t * load_balance_multipath_next_hop_fixup (const load_balance_path_t *nhs, dpo_proto_t drop_proto) { if (0 == vec_len(nhs)) { load_balance_path_t *new_nhs = NULL, *nh; /* * we need something for the load-balance. so use the drop */ vec_add2(new_nhs, nh, 1); nh->path_weight = 1; dpo_copy(&nh->path_dpo, drop_dpo_get(drop_proto)); return (new_nhs); } return (NULL); } /* * Fill in adjacencies in block based on corresponding * next hop adjacencies. */ static void load_balance_fill_buckets_norm (load_balance_t *lb, load_balance_path_t *nhs, dpo_id_t *buckets, u32 n_buckets) { load_balance_path_t *nh; u16 ii, bucket; bucket = 0; /* * the next-hops have normalised weights. that means their sum is the number * of buckets we need to fill. */ vec_foreach (nh, nhs) { for (ii = 0; ii < nh->path_weight; ii++) { ASSERT(bucket < n_buckets); load_balance_set_bucket_i(lb, bucket++, buckets, &nh->path_dpo); } } } static void load_balance_fill_buckets_sticky (load_balance_t *lb, load_balance_path_t *nhs, dpo_id_t *buckets, u32 n_buckets) { load_balance_path_t *nh, *fwding_paths; u16 ii, bucket, fpath; fpath = bucket = 0; fwding_paths = NULL; vec_foreach (nh, nhs) { if (!dpo_is_drop(&nh->path_dpo)) { vec_add1(fwding_paths, *nh); } } if (vec_len(fwding_paths) == 0) fwding_paths = vec_dup(nhs); /* * the next-hops have normalised weights. that means their sum is the number * of buckets we need to fill. */ vec_foreach (nh, nhs) { for (ii = 0; ii < nh->path_weight; ii++) { ASSERT(bucket < n_buckets); if (!dpo_is_drop(&nh->path_dpo)) { load_balance_set_bucket_i(lb, bucket++, buckets, &nh->path_dpo); } else { /* fill the bucks from the next up path */ load_balance_set_bucket_i(lb, bucket++, buckets, &fwding_paths[fpath].path_dpo); fpath = (fpath + 1) % vec_len(fwding_paths); } } } vec_free(fwding_paths); } static void load_balance_fill_buckets (load_balance_t *lb, load_balance_path_t *nhs, dpo_id_t *buckets, u32 n_buckets, load_balance_flags_t flags) { if (flags & LOAD_BALANCE_FLAG_STICKY) { load_balance_fill_buckets_sticky(lb, nhs, buckets, n_buckets); } else { load_balance_fill_buckets_norm(lb, nhs, buckets, n_buckets); } } static inline void load_balance_set_n_buckets (load_balance_t *lb, u32 n_buckets) { lb->lb_n_buckets = n_buckets; lb->lb_n_buckets_minus_1 = n_buckets-1; } void load_balance_multipath_update (const dpo_id_t *dpo, const load_balance_path_t * raw_nhs, load_balance_flags_t flags) { load_balance_path_t *nh, *nhs, *fixed_nhs; u32 sum_of_weights, n_buckets, ii; index_t lbmi, old_lbmi; load_balance_t *lb; dpo_id_t *tmp_dpo; nhs = NULL; ASSERT(DPO_LOAD_BALANCE == dpo->dpoi_type); lb = load_balance_get(dpo->dpoi_index); lb->lb_flags = flags; fixed_nhs = load_balance_multipath_next_hop_fixup(raw_nhs, lb->lb_proto); n_buckets = ip_multipath_normalize_next_hops((NULL == fixed_nhs ? raw_nhs : fixed_nhs), &nhs, &sum_of_weights, multipath_next_hop_error_tolerance); ASSERT (n_buckets >= vec_len (raw_nhs)); /* * Save the old load-balance map used, and get a new one if required. */ old_lbmi = lb->lb_map; if (flags & LOAD_BALANCE_FLAG_USES_MAP) { lbmi = load_balance_map_add_or_lock(n_buckets, sum_of_weights, nhs); } else { lbmi = INDEX_INVALID; } if (0 == lb->lb_n_buckets) { /* * first time initialisation. no packets inflight, so we can write * at leisure. */ load_balance_set_n_buckets(lb, n_buckets); if (!LB_HAS_INLINE_BUCKETS(lb)) vec_validate_aligned(lb->lb_buckets, lb->lb_n_buckets - 1, CLIB_CACHE_LINE_BYTES); load_balance_fill_buckets(lb, nhs, load_balance_get_buckets(lb), n_buckets, flags); lb->lb_map = lbmi; } else { /* * This is a modification of an existing load-balance. * We need to ensure that packets inflight see a consistent state, that * is the number of reported buckets the LB has (read from * lb_n_buckets_minus_1) is not more than it actually has. So if the * number of buckets is increasing, we must update the bucket array first, * then the reported number. vice-versa if the number of buckets goes down. */ if (n_buckets == lb->lb_n_buckets) { /* * no change in the number of buckets. we can simply fill what * is new over what is old. */ load_balance_fill_buckets(lb, nhs, load_balance_get_buckets(lb), n_buckets, flags); lb->lb_map = lbmi; } else if (n_buckets > lb->lb_n_buckets) { /* * we have more buckets. the old load-balance map (if there is one) * will remain valid, i.e. mapping to indices within range, so we * update it last. */ if (n_buckets > LB_NUM_INLINE_BUCKETS && lb->lb_n_buckets <= LB_NUM_INLINE_BUCKETS) { /* * the new increased number of buckets is crossing the threshold * from the inline storage to out-line. Alloc the outline buckets * first, then fixup the number. then reset the inlines. */ ASSERT(NULL == lb->lb_buckets); vec_validate_aligned(lb->lb_buckets, n_buckets - 1, CLIB_CACHE_LINE_BYTES); load_balance_fill_buckets(lb, nhs, lb->lb_buckets, n_buckets, flags); CLIB_MEMORY_BARRIER(); load_balance_set_n_buckets(lb, n_buckets); CLIB_MEMORY_BARRIER(); for (ii = 0; ii < LB_NUM_INLINE_BUCKETS; ii++) { dpo_reset(&lb->lb_buckets_inline[ii]); } } else { if (n_buckets <= LB_NUM_INLINE_BUCKETS) { /* * we are not crossing the threshold and it's still inline buckets. * we can write the new on the old.. */ load_balance_fill_buckets(lb, nhs, load_balance_get_buckets(lb), n_buckets, flags); CLIB_MEMORY_BARRIER(); load_balance_set_n_buckets(lb, n_buckets); } else { /* * we are not crossing the threshold. We need a new bucket array to * hold the increased number of choices. */ dpo_id_t *new_buckets, *old_buckets, *tmp_dpo; new_buckets = NULL; old_buckets = load_balance_get_buckets(lb); vec_validate_aligned(new_buckets, n_buckets - 1, CLIB_CACHE_LINE_BYTES); load_balance_fill_buckets(lb, nhs, new_buckets, n_buckets, flags); CLIB_MEMORY_BARRIER(); lb->lb_buckets = new_buckets; CLIB_MEMORY_BARRIER(); load_balance_set_n_buckets(lb, n_buckets); vec_foreach(tmp_dpo, old_buckets) { dpo_reset(tmp_dpo); } vec_free(old_buckets); } } /* * buckets fixed. ready for the MAP update. */ lb->lb_map = lbmi; } else { /* * bucket size shrinkage. * Any map we have will be based on the old * larger number of buckets, so will be translating to indices * out of range. So the new MAP must be installed first. */ lb->lb_map = lbmi; CLIB_MEMORY_BARRIER(); if (n_buckets <= LB_NUM_INLINE_BUCKETS && lb->lb_n_buckets > LB_NUM_INLINE_BUCKETS) { /* * the new decreased number of buckets is crossing the threshold * from out-line storage to inline: * 1 - Fill the inline buckets, * 2 - fixup the number (and this point the inline buckets are * used). * 3 - free the outline buckets */ load_balance_fill_buckets(lb, nhs, lb->lb_buckets_inline, n_buckets, flags); CLIB_MEMORY_BARRIER(); load_balance_set_n_buckets(lb, n_buckets); CLIB_MEMORY_BARRIER(); vec_foreach(tmp_dpo, lb->lb_buckets) { dpo_reset(tmp_dpo); } vec_free(lb->lb_buckets); } else { /* * not crossing the threshold. * 1 - update the number to the smaller size * 2 - write the new buckets * 3 - reset those no longer used. */ dpo_id_t *buckets; u32 old_n_buckets; old_n_buckets = lb->lb_n_buckets; buckets = load_balance_get_buckets(lb); load_balance_set_n_buckets(lb, n_buckets); CLIB_MEMORY_BARRIER(); load_balance_fill_buckets(lb, nhs, buckets, n_buckets, flags); for (ii = n_buckets; ii < old_n_buckets; ii++) { dpo_reset(&buckets[ii]); } } } } vec_foreach (nh, nhs) { dpo_reset(&nh->path_dpo); } vec_free(nhs); vec_free(fixed_nhs); load_balance_map_unlock(old_lbmi); } static void load_balance_lock (dpo_id_t *dpo) { load_balance_t *lb; lb = load_balance_get(dpo->dpoi_index); lb->lb_locks++; } static void load_balance_destroy (load_balance_t *lb) { dpo_id_t *buckets; int i; buckets = load_balance_get_buckets(lb); for (i = 0; i < lb->lb_n_buckets; i++) { dpo_reset(&buckets[i]); } LB_DBG(lb, "destroy"); if (!LB_HAS_INLINE_BUCKETS(lb)) { vec_free(lb->lb_buckets); } fib_urpf_list_unlock(lb->lb_urpf); load_balance_map_unlock(lb->lb_map); pool_put(load_balance_pool, lb); } static void load_balance_unlock (dpo_id_t *dpo) { load_balance_t *lb; lb = load_balance_get(dpo->dpoi_index); lb->lb_locks--; if (0 == lb->lb_locks) { load_balance_destroy(lb); } } static void load_balance_mem_show (void) { fib_show_memory_usage("load-balance", pool_elts(load_balance_pool), pool_len(load_balance_pool), sizeof(load_balance_t)); load_balance_map_show_mem(); } static u16 load_balance_dpo_get_mtu (const dpo_id_t *dpo) { const dpo_id_t *buckets; load_balance_t *lb; u16 i, mtu = 0xffff; lb = load_balance_get(dpo->dpoi_index); buckets = load_balance_get_buckets(lb); for (i = 0; i < lb->lb_n_buckets; i++) { mtu = clib_min (mtu, dpo_get_mtu (&buckets[i])); } return (mtu); } const static dpo_vft_t lb_vft = { .dv_lock = load_balance_lock, .dv_unlock = load_balance_unlock, .dv_format = format_load_balance_dpo, .dv_mem_show = load_balance_mem_show, .dv_get_mtu = load_balance_dpo_get_mtu, }; /** * @brief The per-protocol VLIB graph nodes that are assigned to a load-balance * object. * * this means that these graph nodes are ones from which a load-balance is the * parent object in the DPO-graph. * * We do not list all the load-balance nodes, such as the *-lookup. instead * we are relying on the correct use of the .sibling_of field when setting * up these sibling nodes. */ const static char* const load_balance_ip4_nodes[] = { "ip4-load-balance", NULL, }; const static char* const load_balance_ip6_nodes[] = { "ip6-load-balance", NULL, }; const static char* const load_balance_mpls_nodes[] = { "mpls-load-balance", NULL, }; const static char* const load_balance_l2_nodes[] = { "l2-load-balance", NULL, }; const static char* const load_balance_nsh_nodes[] = { "nsh-load-balance", NULL }; const static char* const load_balance_bier_nodes[] = { "bier-load-balance", NULL, }; const static char* const * const load_balance_nodes[DPO_PROTO_NUM] = { [DPO_PROTO_IP4] = load_balance_ip4_nodes, [DPO_PROTO_IP6] = load_balance_ip6_nodes, [DPO_PROTO_MPLS] = load_balance_mpls_nodes, [DPO_PROTO_ETHERNET] = load_balance_l2_nodes, [DPO_PROTO_NSH] = load_balance_nsh_nodes, [DPO_PROTO_BIER] = load_balance_bier_nodes, }; void load_balance_module_init (void) { index_t lbi; dpo_register(DPO_LOAD_BALANCE, &lb_vft, load_balance_nodes); /* * Special LB with index zero. we need to define this since the v4 mtrie * assumes an index of 0 implies the ply is empty. therefore all 'real' * adjs need a non-zero index. * This should never be used, but just in case, stack it on a drop. */ lbi = load_balance_create(1, DPO_PROTO_IP4, 0); load_balance_set_bucket(lbi, 0, drop_dpo_get(DPO_PROTO_IP4)); load_balance_logger = vlib_log_register_class("dpo", "load-balance"); load_balance_map_module_init(); } static clib_error_t * load_balance_show (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { index_t lbi = INDEX_INVALID; while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) { if (unformat (input, "%d", &lbi)) ; else break; } if (INDEX_INVALID != lbi) { if (pool_is_free_index(load_balance_pool, lbi)) { vlib_cli_output (vm, "no such load-balance:%d", lbi); } else { vlib_cli_output (vm, "%U", format_load_balance, lbi, LOAD_BALANCE_FORMAT_DETAIL); } } else { load_balance_t *lb; pool_foreach (lb, load_balance_pool) { vlib_cli_output (vm, "%U", format_load_balance, load_balance_get_index(lb), LOAD_BALANCE_FORMAT_NONE); } } return 0; } VLIB_CLI_COMMAND (load_balance_show_command, static) = { .path = "show load-balance", .short_help = "show load-balance [<index>]", .function = load_balance_show, }; always_inline u32 ip_flow_hash (void *data) { ip4_header_t *iph = (ip4_header_t *) data; if ((iph->ip_version_and_header_length & 0xF0) == 0x40) return ip4_compute_flow_hash (iph, IP_FLOW_HASH_DEFAULT); else return ip6_compute_flow_hash ((ip6_header_t *) iph, IP_FLOW_HASH_DEFAULT); } always_inline u64 mac_to_u64 (u8 * m) { return (*((u64 *) m) & 0xffffffffffff); } always_inline u32 l2_flow_hash (vlib_buffer_t * b0) { ethernet_header_t *eh; u64 a, b, c; uword is_ip, eh_size; u16 eh_type; eh = vlib_buffer_get_current (b0); eh_type = clib_net_to_host_u16 (eh->type); eh_size = ethernet_buffer_header_size (b0); is_ip = (eh_type == ETHERNET_TYPE_IP4 || eh_type == ETHERNET_TYPE_IP6); /* since we have 2 cache lines, use them */ if (is_ip) a = ip_flow_hash ((u8 *) vlib_buffer_get_current (b0) + eh_size); else a = eh->type; b = mac_to_u64 ((u8 *) eh->dst_address); c = mac_to_u64 ((u8 *) eh->src_address); hash_mix64 (a, b, c); return (u32) c; } typedef struct load_balance_trace_t_ { index_t lb_index; } load_balance_trace_t; always_inline uword load_balance_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, int is_l2) { u32 n_left_from, next_index, *from, *to_next; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; next_index = node->cached_next_index; while (n_left_from > 0) { u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { vlib_buffer_t *b0; u32 bi0, lbi0, next0; const dpo_id_t *dpo0; const load_balance_t *lb0; bi0 = from[0]; to_next[0] = bi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); /* lookup dst + src mac */ lbi0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX]; lb0 = load_balance_get(lbi0); if (is_l2) { vnet_buffer(b0)->ip.flow_hash = l2_flow_hash(b0); } else { /* it's BIER */ const bier_hdr_t *bh0 = vlib_buffer_get_current(b0); vnet_buffer(b0)->ip.flow_hash = bier_compute_flow_hash(bh0); } dpo0 = load_balance_get_bucket_i(lb0, vnet_buffer(b0)->ip.flow_hash & (lb0->lb_n_buckets_minus_1)); next0 = dpo0->dpoi_next_node; vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index; if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) { load_balance_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr)); tr->lb_index = lbi0; } vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, bi0, next0); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } return frame->n_vectors; } static uword l2_load_balance (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return (load_balance_inline(vm, node, frame, 1)); } static u8 * format_l2_load_balance_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *); s = format (s, "L2-load-balance: index %d", t->lb_index); return s; } /** * @brief */ VLIB_REGISTER_NODE (l2_load_balance_node) = { .function = l2_load_balance, .name = "l2-load-balance", .vector_size = sizeof (u32), .format_trace = format_l2_load_balance_trace, .n_next_nodes = 1, .next_nodes = { [0] = "error-drop", }, }; static uword nsh_load_balance (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, next_index, *from, *to_next; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; next_index = node->cached_next_index; while (n_left_from > 0) { u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { vlib_buffer_t *b0; u32 bi0, lbi0, next0, *nsh0; const dpo_id_t *dpo0; const load_balance_t *lb0; bi0 = from[0]; to_next[0] = bi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); lbi0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX]; lb0 = load_balance_get(lbi0); /* SPI + SI are the second word of the NSH header */ nsh0 = vlib_buffer_get_current (b0); vnet_buffer(b0)->ip.flow_hash = nsh0[1] % lb0->lb_n_buckets; dpo0 = load_balance_get_bucket_i(lb0, vnet_buffer(b0)->ip.flow_hash & (lb0->lb_n_buckets_minus_1)); next0 = dpo0->dpoi_next_node; vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index; if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) { load_balance_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr)); tr->lb_index = lbi0; } vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, bi0, next0); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } return frame->n_vectors; } static u8 * format_nsh_load_balance_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *); s = format (s, "NSH-load-balance: index %d", t->lb_index); return s; } /** * @brief */ VLIB_REGISTER_NODE (nsh_load_balance_node) = { .function = nsh_load_balance, .name = "nsh-load-balance", .vector_size = sizeof (u32), .format_trace = format_nsh_load_balance_trace, .n_next_nodes = 1, .next_nodes = { [0] = "error-drop", }, }; static u8 * format_bier_load_balance_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *); s = format (s, "BIER-load-balance: index %d", t->lb_index); return s; } static uword bier_load_balance (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return (load_balance_inline(vm, node, frame, 0)); } /** * @brief */ VLIB_REGISTER_NODE (bier_load_balance_node) = { .function = bier_load_balance, .name = "bier-load-balance", .vector_size = sizeof (u32), .format_trace = format_bier_load_balance_trace, .sibling_of = "mpls-load-balance", }; // clang-format on