+/**
+ * @brief Lookup NSH SD FIB entry
+ *
+ * Does an SPI+SI lookup in the NSH LISP FIB.
+ *
+ * @param[in] lgm Reference to @ref lisp_gpe_main_t.
+ * @param[in] spi_si SPI + SI.
+ *
+ * @return next node index.
+ */
+const dpo_id_t *
+lisp_nsh_fib_lookup (lisp_gpe_main_t * lgm, u32 spi_si_net_order)
+{
+ int rv;
+ BVT (clib_bihash_kv) kv, value;
+
+ memset (&kv, 0, sizeof (kv));
+ kv.key[0] = spi_si_net_order;
+ rv = BV (clib_bihash_search_inline_2) (&lgm->nsh_fib, &kv, &value);
+
+ if (rv != 0)
+ {
+ return lgm->nsh_cp_lkup;
+ }
+ else
+ {
+ lisp_gpe_fwd_entry_t *lfe;
+ lfe = pool_elt_at_index (lgm->lisp_fwd_entry_pool, value.value);
+ return &lfe->nsh.choice;
+ }
+}
+
+/**
+ * @brief Add/del NSH FIB entry
+ *
+ * Inserts value in NSH FIB keyed by SPI+SI. If entry is
+ * overwritten the associated value is returned.
+ *
+ * @param[in] lgm Reference to @ref lisp_gpe_main_t.
+ * @param[in] spi_si SPI + SI.
+ * @param[in] dpo Load balanced mapped to SPI + SI
+ *
+ * @return ~0 or value of overwritten entry.
+ */
+static u32
+lisp_nsh_fib_add_del_entry (u32 spi_si_host_order, u32 lfei, u8 is_add)
+{
+ lisp_gpe_main_t *lgm = &lisp_gpe_main;
+ BVT (clib_bihash_kv) kv, value;
+ u32 old_val = ~0;
+
+ memset (&kv, 0, sizeof (kv));
+ kv.key[0] = clib_host_to_net_u32 (spi_si_host_order);
+ kv.value = 0ULL;
+
+ if (BV (clib_bihash_search) (&lgm->nsh_fib, &kv, &value) == 0)
+ old_val = value.value;
+
+ if (!is_add)
+ BV (clib_bihash_add_del) (&lgm->nsh_fib, &kv, 0 /* is_add */ );
+ else
+ {
+ kv.value = lfei;
+ BV (clib_bihash_add_del) (&lgm->nsh_fib, &kv, 1 /* is_add */ );
+ }
+ return old_val;
+}
+
+#define NSH_FIB_DEFAULT_HASH_NUM_BUCKETS (64 * 1024)
+#define NSH_FIB_DEFAULT_HASH_MEMORY_SIZE (32<<20)
+
+static void
+nsh_fib_init (lisp_gpe_main_t * lgm)
+{
+ BV (clib_bihash_init) (&lgm->nsh_fib, "nsh fib",
+ 1 << max_log2 (NSH_FIB_DEFAULT_HASH_NUM_BUCKETS),
+ NSH_FIB_DEFAULT_HASH_MEMORY_SIZE);
+
+ /*
+ * the result from a 'miss' in a NSH Table
+ */
+ lgm->nsh_cp_lkup = lisp_cp_dpo_get (DPO_PROTO_NSH);
+}
+
+static void
+del_nsh_fwd_entry_i (lisp_gpe_main_t * lgm, lisp_gpe_fwd_entry_t * lfe)
+{
+ lisp_fwd_path_t *path;
+
+ if (LISP_GPE_FWD_ENTRY_TYPE_NEGATIVE != lfe->type)
+ {
+ vec_foreach (path, lfe->paths)
+ {
+ lisp_gpe_adjacency_unlock (path->lisp_adj);
+ }
+ fib_path_list_child_remove (lfe->nsh.path_list_index,
+ lfe->nsh.child_index);
+ dpo_reset (&lfe->nsh.choice);
+ }
+
+ lisp_nsh_fib_add_del_entry (fid_addr_nsh (&lfe->key->rmt), (u32) ~ 0, 0);
+
+ hash_unset_mem (lgm->lisp_gpe_fwd_entries, lfe->key);
+ clib_mem_free (lfe->key);
+ pool_put (lgm->lisp_fwd_entry_pool, lfe);
+}
+
+/**
+ * @brief Delete LISP NSH forwarding entry.
+ *
+ * Coordinates the removal of forwarding entries for NSH LISP overlay:
+ *
+ * @param[in] lgm Reference to @ref lisp_gpe_main_t.
+ * @param[in] a Parameters for building the forwarding entry.
+ *
+ * @return 0 on success.
+ */
+static int
+del_nsh_fwd_entry (lisp_gpe_main_t * lgm,
+ vnet_lisp_gpe_add_del_fwd_entry_args_t * a)
+{
+ lisp_gpe_fwd_entry_key_t key;
+ lisp_gpe_fwd_entry_t *lfe;
+
+ lfe = find_fwd_entry (lgm, a, &key);
+
+ if (NULL == lfe)
+ return VNET_API_ERROR_INVALID_VALUE;
+
+ del_nsh_fwd_entry_i (lgm, lfe);
+
+ return (0);
+}
+
+/**
+ * @brief Construct and insert the forwarding information used by an NSH entry
+ */
+static void
+lisp_gpe_nsh_update_fwding (lisp_gpe_fwd_entry_t * lfe)
+{
+ lisp_gpe_main_t *lgm = vnet_lisp_gpe_get_main ();
+ dpo_id_t dpo = DPO_INVALID;
+ vnet_hw_interface_t *hi;
+ uword *hip;
+
+ if (LISP_GPE_FWD_ENTRY_TYPE_NEGATIVE != lfe->type)
+ {
+ fib_path_list_contribute_forwarding (lfe->nsh.path_list_index,
+ FIB_FORW_CHAIN_TYPE_NSH,
+ &lfe->nsh.dpo);
+
+ /*
+ * LISP encap is always the same for this SPI+SI so we do that hash now
+ * and stack on the choice.
+ */
+ if (DPO_LOAD_BALANCE == lfe->nsh.dpo.dpoi_type)
+ {
+ const dpo_id_t *tmp;
+ const load_balance_t *lb;
+ int hash;
+
+ lb = load_balance_get (lfe->nsh.dpo.dpoi_index);
+ hash = fid_addr_nsh (&lfe->key->rmt) % lb->lb_n_buckets;
+ tmp =
+ load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1);
+
+ dpo_copy (&dpo, tmp);
+ }
+ }
+ else
+ {
+ switch (lfe->action)
+ {
+ case SEND_MAP_REQUEST:
+ dpo_copy (&dpo, lgm->nsh_cp_lkup);
+ break;
+ case NO_ACTION:
+ case FORWARD_NATIVE:
+ case DROP:
+ dpo_copy (&dpo, drop_dpo_get (DPO_PROTO_NSH));
+ }
+ }
+
+ /* We have only one nsh-lisp interface (no NSH virtualization) */
+ hip = hash_get (lgm->nsh_ifaces.hw_if_index_by_dp_table, 0);
+ if (hip)
+ {
+ hi = vnet_get_hw_interface (lgm->vnet_main, hip[0]);
+ dpo_stack_from_node (hi->tx_node_index, &lfe->nsh.choice, &dpo);
+ }
+ /* add entry to nsh lisp fib */
+ lisp_nsh_fib_add_del_entry (fid_addr_nsh (&lfe->key->rmt),
+ lfe - lgm->lisp_fwd_entry_pool, 1);
+ dpo_reset (&dpo);
+
+}
+
+/**
+ * @brief Add LISP NSH forwarding entry.
+ *
+ * Coordinates the creation of forwarding entries for L2 LISP overlay:
+ * creates lisp-gpe tunnel and injects new entry in Source/Dest L2 FIB.
+ *
+ * @param[in] lgm Reference to @ref lisp_gpe_main_t.
+ * @param[in] a Parameters for building the forwarding entry.
+ *
+ * @return 0 on success.
+ */
+static int
+add_nsh_fwd_entry (lisp_gpe_main_t * lgm,
+ vnet_lisp_gpe_add_del_fwd_entry_args_t * a)
+{
+ lisp_gpe_fwd_entry_key_t key;
+ lisp_gpe_fwd_entry_t *lfe;
+
+ lfe = find_fwd_entry (lgm, a, &key);
+
+ if (NULL != lfe)
+ /* don't support updates */
+ return VNET_API_ERROR_INVALID_VALUE;
+
+ pool_get (lgm->lisp_fwd_entry_pool, lfe);
+ memset (lfe, 0, sizeof (*lfe));
+ lfe->key = clib_mem_alloc (sizeof (key));
+ memcpy (lfe->key, &key, sizeof (key));
+
+ hash_set_mem (lgm->lisp_gpe_fwd_entries, lfe->key,
+ lfe - lgm->lisp_fwd_entry_pool);
+
+ lfe->type = (a->is_negative ?
+ LISP_GPE_FWD_ENTRY_TYPE_NEGATIVE :
+ LISP_GPE_FWD_ENTRY_TYPE_NORMAL);
+ lfe->tenant = 0;
+
+ if (LISP_GPE_FWD_ENTRY_TYPE_NEGATIVE != lfe->type)
+ {
+ fib_route_path_t *rpaths;
+
+ /*
+ * Make the sorted array of LISP paths with their resp. adjacency
+ */
+ lisp_gpe_fwd_entry_mk_paths (lfe, a);
+
+ /*
+ * From the LISP paths, construct a FIB path list that will
+ * contribute a load-balance.
+ */
+ rpaths = lisp_gpe_mk_fib_paths (lfe->paths);
+
+ lfe->nsh.path_list_index =
+ fib_path_list_create (FIB_PATH_LIST_FLAG_NONE, rpaths);
+
+ /*
+ * become a child of the path-list so we receive updates when
+ * its forwarding state changes. this includes an implicit lock.
+ */
+ lfe->nsh.child_index =
+ fib_path_list_child_add (lfe->nsh.path_list_index,
+ FIB_NODE_TYPE_LISP_GPE_FWD_ENTRY,
+ lfe - lgm->lisp_fwd_entry_pool);
+ }
+ else
+ {
+ lfe->action = a->action;
+ }
+
+ lisp_gpe_nsh_update_fwding (lfe);
+
+ return 0;
+}
+