aboutsummaryrefslogtreecommitdiffstats
path: root/vpp/vnet/vnet/dpo/load_balance.c
diff options
context:
space:
mode:
Diffstat (limited to 'vpp/vnet/vnet/dpo/load_balance.c')
-rw-r--r--vpp/vnet/vnet/dpo/load_balance.c996
1 files changed, 996 insertions, 0 deletions
diff --git a/vpp/vnet/vnet/dpo/load_balance.c b/vpp/vnet/vnet/dpo/load_balance.c
new file mode 100644
index 00000000..e70a7a30
--- /dev/null
+++ b/vpp/vnet/vnet/dpo/load_balance.c
@@ -0,0 +1,996 @@
+/*
+ * 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/ip/lookup.h>
+#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>
+
+/*
+ * distribution error tolerance for load-balancing
+ */
+const f64 multipath_next_hop_error_tolerance = 0.1;
+
+#undef LB_DEBUG
+
+#ifdef LB_DEBUG
+#define LB_DBG(_lb, _fmt, _args...) \
+{ \
+ u8* _tmp =NULL; \
+ clib_warning("lb:[%s]:" _fmt, \
+ load_balance_format(load_balance_get_index((_lb)), \
+ 0, _tmp), \
+ ##_args); \
+ vec_free(_tmp); \
+}
+#else
+#define LB_DBG(_p, _fmt, _args...)
+#endif
+
+
+/**
+ * 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;
+
+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;
+
+ pool_get_aligned(load_balance_pool, lb, CLIB_CACHE_LINE_BYTES);
+ memset(lb, 0, sizeof(*lb));
+
+ lb->lb_map = INDEX_INVALID;
+ lb->lb_urpf = INDEX_INVALID;
+ 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));
+
+ 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, "[index:%d buckets:%d ", lbi, lb->lb_n_buckets);
+ s = format(s, "uRPF:%d ", lb->lb_urpf);
+ 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));
+}
+
+
+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);
+}
+
+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 (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 represenation 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 (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 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);
+ 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);
+ 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);
+ 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);
+ 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);
+ 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);
+ 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);
+ 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);
+
+ for (ii = old_n_buckets-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();
+}
+
+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,
+};
+
+/**
+ * @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 * 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,
+};
+
+void
+load_balance_module_init (void)
+{
+ dpo_register(DPO_LOAD_BALANCE, &lb_vft, load_balance_nodes);
+
+ 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)
+ {
+ 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;
+
+static uword
+l2_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;
+ 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);
+
+ vnet_buffer(b0)->ip.flow_hash = l2_flow_hash(b0);
+
+ 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_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_load_balance_trace,
+ .n_next_nodes = 1,
+ .next_nodes = {
+ [0] = "error-drop",
+ },
+};