Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 993 insertions, 0 deletions

diff --git a/src/vnet/dpo/load_balance.c b/src/vnet/dpo/load_balance.c
new file mode 100644
index 00000000000..a244776ffb8
--- /dev/null
+++ b/src/vnet/dpo/load_balance.c
@@ -0,0 +1,993 @@
+/*
+ * 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 (load_balance_path_t * n1,
+                         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 (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 (load_balance_path_t *nhs,
+                                       dpo_proto_t drop_proto)
+{
+    if (0 == vec_len(nhs))
+    {
+        load_balance_path_t *nh;
+
+        /*
+         * we need something for the load-balance. so use the drop
+         */
+        vec_add2(nhs, nh, 1);
+
+        nh->path_weight = 1;
+        dpo_copy(&nh->path_dpo, drop_dpo_get(drop_proto));
+    }
+
+    return (nhs);
+}
+
+/*
+ * 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,
+                               load_balance_path_t * raw_next_hops,
+                               load_balance_flags_t flags)
+{
+    u32 sum_of_weights,n_buckets, ii;
+    load_balance_path_t * nh, * nhs;
+    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);
+    raw_next_hops =
+        load_balance_multipath_next_hop_fixup(raw_next_hops,
+                                              lb->lb_proto);
+    n_buckets =
+        ip_multipath_normalize_next_hops(raw_next_hops,
+                                         &nhs,
+                                         &sum_of_weights,
+                                         multipath_next_hop_error_tolerance);
+
+    ASSERT (n_buckets >= vec_len (raw_next_hops));
+
+    /*
+     * 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);
+
+    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",
+  },
+};