src/vnet/fib/ip6_fib.c - fdio/vpp - Gitiles

 /*
  * 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/fib/ip6_fib.h>
 #include <vnet/fib/fib_table.h>
 #include <vnet/dpo/ip6_ll_dpo.h>

 #include <vppinfra/bihash_24_8.h>
 #include <vppinfra/bihash_template.c>

 static void
 vnet_ip6_fib_init (u32 fib_index)
 {
     fib_prefix_t pfx = {
 	.fp_proto = FIB_PROTOCOL_IP6,
 	.fp_len = 0,
 	.fp_addr = {
 	    .ip6 = {
 		{ 0, 0, },
 	    },
 	}
     };

     /*
      * Add the default route.
      */
     fib_table_entry_special_add(fib_index,
 				&pfx,
 				FIB_SOURCE_DEFAULT_ROUTE,
 				FIB_ENTRY_FLAG_DROP);

     /*
      * all link local via the link local lookup DPO
      */
     pfx.fp_addr.ip6.as_u64[0] = clib_host_to_net_u64 (0xFE80000000000000ULL);
     pfx.fp_addr.ip6.as_u64[1] = 0;
     pfx.fp_len = 10;
     fib_table_entry_special_dpo_add(fib_index,
                                     &pfx,
                                     FIB_SOURCE_SPECIAL,
                                     FIB_ENTRY_FLAG_NONE,
                                     ip6_ll_dpo_get());
 }

 static u32
 create_fib_with_table_id (u32 table_id,
                           fib_source_t src,
                           fib_table_flags_t flags,
                           u8 *desc)
 {
     fib_table_t *fib_table;
     ip6_fib_t *v6_fib;

     pool_get(ip6_main.fibs, fib_table);
     pool_get_aligned(ip6_main.v6_fibs, v6_fib, CLIB_CACHE_LINE_BYTES);

     clib_memset(fib_table, 0, sizeof(*fib_table));
     clib_memset(v6_fib, 0, sizeof(*v6_fib));

     ASSERT((fib_table - ip6_main.fibs) ==
            (v6_fib - ip6_main.v6_fibs));

     fib_table->ft_proto = FIB_PROTOCOL_IP6;
     fib_table->ft_index =
 	    v6_fib->index =
                 (fib_table - ip6_main.fibs);

     hash_set(ip6_main.fib_index_by_table_id, table_id, fib_table->ft_index);

     fib_table->ft_table_id =
 	v6_fib->table_id =
 	    table_id;
     fib_table->ft_flow_hash_config = IP_FLOW_HASH_DEFAULT;
     fib_table->ft_flags = flags;
     fib_table->ft_desc = desc;

     vnet_ip6_fib_init(fib_table->ft_index);
     fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP6, src);

     return (fib_table->ft_index);
 }

 u32
 ip6_fib_table_find_or_create_and_lock (u32 table_id,
                                        fib_source_t src)
 {
     uword * p;

     p = hash_get (ip6_main.fib_index_by_table_id, table_id);
     if (NULL == p)
 	return create_fib_with_table_id(table_id, src,
                                         FIB_TABLE_FLAG_NONE,
                                         NULL);

     fib_table_lock(p[0], FIB_PROTOCOL_IP6, src);

     return (p[0]);
 }

 u32
 ip6_fib_table_create_and_lock (fib_source_t src,
                                fib_table_flags_t flags,
                                u8 *desc)
 {
     return (create_fib_with_table_id(~0, src, flags, desc));
 }

 void
 ip6_fib_table_destroy (u32 fib_index)
 {
     /*
      * all link local first ...
      */
     fib_prefix_t pfx = {
 	.fp_proto = FIB_PROTOCOL_IP6,
 	.fp_len = 10,
 	.fp_addr = {
 	    .ip6 = {
                 .as_u8 = {
                     [0] = 0xFE,
                     [1] = 0x80,
                 },
 	    },
 	}
     };
     fib_table_entry_delete(fib_index,
                            &pfx,
                            FIB_SOURCE_SPECIAL);

     /*
      * ... then the default route.
      */
     pfx.fp_addr.ip6.as_u64[0] = 0;
     pfx.fp_len = 00;
     fib_table_entry_special_remove(fib_index,
 				   &pfx,
 				   FIB_SOURCE_DEFAULT_ROUTE);

     fib_table_t *fib_table = fib_table_get(fib_index, FIB_PROTOCOL_IP6);
     fib_source_t source;

     /*
      * validate no more routes.
      */
 #if CLIB_DEBUG > 0
     if (0 != fib_table->ft_total_route_counts)
         fib_table_assert_empty(fib_table);
 #endif

     vec_foreach_index(source, fib_table->ft_src_route_counts)
     {
 	ASSERT(0 == fib_table->ft_src_route_counts[source]);
     }

     if (~0 != fib_table->ft_table_id)
     {
 	hash_unset (ip6_main.fib_index_by_table_id, fib_table->ft_table_id);
     }
     vec_free(fib_table->ft_src_route_counts);
     pool_put_index(ip6_main.v6_fibs, fib_table->ft_index);
     pool_put(ip6_main.fibs, fib_table);
 }

 fib_node_index_t
 ip6_fib_table_lookup (u32 fib_index,
 		      const ip6_address_t *addr,
 		      u32 len)
 {
     ip6_fib_table_instance_t *table;
     clib_bihash_kv_24_8_t kv, value;
     int i, n_p, rv;
     u64 fib;

     table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
     n_p = vec_len (table->prefix_lengths_in_search_order);

     kv.key[0] = addr->as_u64[0];
     kv.key[1] = addr->as_u64[1];
     fib = ((u64)((fib_index))<<32);

     /*
      * start search from a mask length same length or shorter.
      * we don't want matches longer than the mask passed
      */
     i = 0;
     while (i < n_p && table->prefix_lengths_in_search_order[i] > len)
     {
         i++;
     }

     for (; i < n_p; i++)
     {
 	int dst_address_length = table->prefix_lengths_in_search_order[i];
 	ip6_address_t * mask = &ip6_main.fib_masks[dst_address_length];

 	ASSERT(dst_address_length >= 0 && dst_address_length <= 128);
 	//As lengths are decreasing, masks are increasingly specific.
 	kv.key[0] &= mask->as_u64[0];
 	kv.key[1] &= mask->as_u64[1];
 	kv.key[2] = fib | dst_address_length;

 	rv = clib_bihash_search_inline_2_24_8(&table->ip6_hash, &kv, &value);
 	if (rv == 0)
 	    return value.value;
     }

     return (FIB_NODE_INDEX_INVALID);
 }

 fib_node_index_t
 ip6_fib_table_lookup_exact_match (u32 fib_index,
 				  const ip6_address_t *addr,
 				  u32 len)
 {
     ip6_fib_table_instance_t *table;
     clib_bihash_kv_24_8_t kv, value;
     ip6_address_t *mask;
     u64 fib;
     int rv;

     table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
     mask = &ip6_main.fib_masks[len];
     fib = ((u64)((fib_index))<<32);

     kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
     kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
     kv.key[2] = fib | len;

     rv = clib_bihash_search_inline_2_24_8(&table->ip6_hash, &kv, &value);
     if (rv == 0)
 	return value.value;

     return (FIB_NODE_INDEX_INVALID);
 }

 static void
 compute_prefix_lengths_in_search_order (ip6_fib_table_instance_t *table)
 {
     u8 *old, *prefix_lengths_in_search_order = NULL;
     int i;

     /*
      * build the list in a scratch space then cutover so the workers
      * can continue uninterrupted.
      */
     old = table->prefix_lengths_in_search_order;

     /* Note: bitmap reversed so this is in fact a longest prefix match */
     clib_bitmap_foreach (i, table->non_empty_dst_address_length_bitmap,
     ({
 	int dst_address_length = 128 - i;
 	vec_add1(prefix_lengths_in_search_order, dst_address_length);
     }));

     table->prefix_lengths_in_search_order = prefix_lengths_in_search_order;

     /*
      * let the workers go once round the track before we free the old set
      */
     vlib_worker_wait_one_loop();
     vec_free(old);
 }

 void
 ip6_fib_table_entry_remove (u32 fib_index,
 			    const ip6_address_t *addr,
 			    u32 len)
 {
     ip6_fib_table_instance_t *table;
     clib_bihash_kv_24_8_t kv;
     ip6_address_t *mask;
     u64 fib;

     table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
     mask = &ip6_main.fib_masks[len];
     fib = ((u64)((fib_index))<<32);

     kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
     kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
     kv.key[2] = fib | len;

     clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 0);

     /* refcount accounting */
     ASSERT (table->dst_address_length_refcounts[len] > 0);
     if (--table->dst_address_length_refcounts[len] == 0)
     {
 	table->non_empty_dst_address_length_bitmap =
             clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
                              128 - len, 0);
 	compute_prefix_lengths_in_search_order (table);
     }
 }

 void
 ip6_fib_table_entry_insert (u32 fib_index,
 			    const ip6_address_t *addr,
 			    u32 len,
 			    fib_node_index_t fib_entry_index)
 {
     ip6_fib_table_instance_t *table;
     clib_bihash_kv_24_8_t kv;
     ip6_address_t *mask;
     u64 fib;

     table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
     mask = &ip6_main.fib_masks[len];
     fib = ((u64)((fib_index))<<32);

     kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
     kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
     kv.key[2] = fib | len;
     kv.value = fib_entry_index;

     clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 1);

     if (0 == table->dst_address_length_refcounts[len]++)
     {
         table->non_empty_dst_address_length_bitmap =
             clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
                              128 - len, 1);
         compute_prefix_lengths_in_search_order (table);
     }
 }

 u32 ip6_fib_table_fwding_lookup_with_if_index (ip6_main_t * im,
 					       u32 sw_if_index,
 					       const ip6_address_t * dst)
 {
     u32 fib_index = vec_elt (im->fib_index_by_sw_if_index, sw_if_index);
     return ip6_fib_table_fwding_lookup(fib_index, dst);
 }

 u32
 ip6_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
 {
     if (sw_if_index >= vec_len(ip6_main.fib_index_by_sw_if_index))
     {
 	/*
 	 * This is the case for interfaces that are not yet mapped to
 	 * a IP table
 	 */
 	return (~0);
     }
     return (ip6_main.fib_index_by_sw_if_index[sw_if_index]);
 }

 void
 ip6_fib_table_fwding_dpo_update (u32 fib_index,
 				 const ip6_address_t *addr,
 				 u32 len,
 				 const dpo_id_t *dpo)
 {
     ip6_fib_table_instance_t *table;
     clib_bihash_kv_24_8_t kv;
     ip6_address_t *mask;
     u64 fib;

     table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
     mask = &ip6_main.fib_masks[len];
     fib = ((u64)((fib_index))<<32);

     kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
     kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
     kv.key[2] = fib | len;
     kv.value = dpo->dpoi_index;

     clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 1);

     if (0 == table->dst_address_length_refcounts[len]++)
     {
         table->non_empty_dst_address_length_bitmap =
             clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
                              128 - len, 1);
         compute_prefix_lengths_in_search_order (table);
     }
 }

 void
 ip6_fib_table_fwding_dpo_remove (u32 fib_index,
 				 const ip6_address_t *addr,
 				 u32 len,
 				 const dpo_id_t *dpo)
 {
     ip6_fib_table_instance_t *table;
     clib_bihash_kv_24_8_t kv;
     ip6_address_t *mask;
     u64 fib;

     table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
     mask = &ip6_main.fib_masks[len];
     fib = ((u64)((fib_index))<<32);

     kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
     kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
     kv.key[2] = fib | len;
     kv.value = dpo->dpoi_index;

     clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 0);

     /* refcount accounting */
     ASSERT (table->dst_address_length_refcounts[len] > 0);
     if (--table->dst_address_length_refcounts[len] == 0)
     {
 	table->non_empty_dst_address_length_bitmap =
             clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
                              128 - len, 0);
 	compute_prefix_lengths_in_search_order (table);
     }
 }

 /**
  * @brief Context when walking the IPv6 table. Since all VRFs are in the
  * same hash table, we need to filter only those we need as we walk
  */
 typedef struct ip6_fib_walk_ctx_t_
 {
     u32 i6w_fib_index;
     fib_table_walk_fn_t i6w_fn;
     void *i6w_ctx;
     fib_prefix_t i6w_root;
     fib_prefix_t *i6w_sub_trees;
 } ip6_fib_walk_ctx_t;

 static int
 ip6_fib_walk_cb (clib_bihash_kv_24_8_t * kvp,
                  void *arg)
 {
     ip6_fib_walk_ctx_t *ctx = arg;
     ip6_address_t key;

     if ((kvp->key[2] >> 32) == ctx->i6w_fib_index)
     {
         key.as_u64[0] = kvp->key[0];
         key.as_u64[1] = kvp->key[1];

         if (ip6_destination_matches_route(&ip6_main,
                                           &key,
                                           &ctx->i6w_root.fp_addr.ip6,
                                           ctx->i6w_root.fp_len))
         {
             const fib_prefix_t *sub_tree;
             int skip = 0;

             /*
              * exclude sub-trees the walk does not want to explore
              */
             vec_foreach(sub_tree, ctx->i6w_sub_trees)
             {
                 if (ip6_destination_matches_route(&ip6_main,
                                                   &key,
                                                   &sub_tree->fp_addr.ip6,
                                                   sub_tree->fp_len))
                 {
                     skip = 1;
                     break;
                 }
             }

             if (!skip)
             {
                 switch (ctx->i6w_fn(kvp->value, ctx->i6w_ctx))
                 {
                 case FIB_TABLE_WALK_CONTINUE:
                     break;
                 case FIB_TABLE_WALK_SUB_TREE_STOP: {
                     fib_prefix_t pfx = {
                         .fp_proto = FIB_PROTOCOL_IP6,
                         .fp_len = kvp->key[2] & 0xffffffff,
                         .fp_addr.ip6 = key,
                     };
                     vec_add1(ctx->i6w_sub_trees, pfx);
                     break;
                 }
                 case FIB_TABLE_WALK_STOP:
                     goto done;
                 }
             }
         }
     }
 done:

     return (1);
 }

 void
 ip6_fib_table_walk (u32 fib_index,
                     fib_table_walk_fn_t fn,
                     void *arg)
 {
     ip6_fib_walk_ctx_t ctx = {
         .i6w_fib_index = fib_index,
         .i6w_fn = fn,
         .i6w_ctx = arg,
         .i6w_root = {
             .fp_proto = FIB_PROTOCOL_IP6,
         },
         .i6w_sub_trees = NULL,
     };

     clib_bihash_foreach_key_value_pair_24_8(
         &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
         ip6_fib_walk_cb,
         &ctx);

     vec_free(ctx.i6w_sub_trees);
 }

 void
 ip6_fib_table_sub_tree_walk (u32 fib_index,
                              const fib_prefix_t *root,
                              fib_table_walk_fn_t fn,
                              void *arg)
 {
     ip6_fib_walk_ctx_t ctx = {
         .i6w_fib_index = fib_index,
         .i6w_fn = fn,
         .i6w_ctx = arg,
         .i6w_root = *root,
     };

     clib_bihash_foreach_key_value_pair_24_8(
         &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
         ip6_fib_walk_cb,
         &ctx);
 }

 typedef struct ip6_fib_show_ctx_t_ {
     fib_node_index_t *entries;
 } ip6_fib_show_ctx_t;

 static fib_table_walk_rc_t
 ip6_fib_table_show_walk (fib_node_index_t fib_entry_index,
                          void *arg)
 {
     ip6_fib_show_ctx_t *ctx = arg;

     vec_add1(ctx->entries, fib_entry_index);

     return (FIB_TABLE_WALK_CONTINUE);
 }

 static void
 ip6_fib_table_show_all (ip6_fib_t *fib,
 			vlib_main_t * vm)
 {
     fib_node_index_t *fib_entry_index;
     ip6_fib_show_ctx_t ctx = {
 	.entries = NULL,
     };

     ip6_fib_table_walk(fib->index, ip6_fib_table_show_walk, &ctx);
     vec_sort_with_function(ctx.entries, fib_entry_cmp_for_sort);

     vec_foreach(fib_entry_index, ctx.entries)
     {
 	vlib_cli_output(vm, "%U",
                         format_fib_entry,
                         *fib_entry_index,
                         FIB_ENTRY_FORMAT_BRIEF);
     }

     vec_free(ctx.entries);
 }

 static void
 ip6_fib_table_show_one (ip6_fib_t *fib,
 			vlib_main_t * vm,
 			ip6_address_t *address,
 			u32 mask_len,
                         int detail)
 {
     vlib_cli_output(vm, "%U",
                     format_fib_entry,
                     ip6_fib_table_lookup(fib->index, address, mask_len),
                     (detail ?
                      FIB_ENTRY_FORMAT_DETAIL2:
                      FIB_ENTRY_FORMAT_DETAIL));
 }

 u8 *
 format_ip6_fib_table_memory (u8 * s, va_list * args)
 {
     uword bytes_inuse;

     bytes_inuse = (alloc_arena_next(&(ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash)) +
                    alloc_arena_next(&(ip6_main.ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash)));

     s = format(s, "%=30s %=6d %=12ld\n",
                "IPv6 unicast",
                pool_elts(ip6_main.fibs),
                bytes_inuse);
     return (s);
 }

 typedef struct {
   u32 fib_index;
   u64 count_by_prefix_length[129];
 } count_routes_in_fib_at_prefix_length_arg_t;

 static int
 count_routes_in_fib_at_prefix_length (clib_bihash_kv_24_8_t * kvp,
                                       void *arg)
 {
   count_routes_in_fib_at_prefix_length_arg_t * ap = arg;
   int mask_width;

   if ((kvp->key[2]>>32) != ap->fib_index)
       return (BIHASH_WALK_CONTINUE);

   mask_width = kvp->key[2] & 0xFF;

   ap->count_by_prefix_length[mask_width]++;

   return (BIHASH_WALK_CONTINUE);
 }

 static clib_error_t *
 ip6_show_fib (vlib_main_t * vm,
 	      unformat_input_t * input,
 	      vlib_cli_command_t * cmd)
 {
     count_routes_in_fib_at_prefix_length_arg_t _ca, *ca = &_ca;
     ip6_main_t * im6 = &ip6_main;
     fib_table_t *fib_table;
     ip6_fib_t * fib;
     int verbose, matching;
     ip6_address_t matching_address;
     u32 mask_len  = 128;
     int table_id = -1, fib_index = ~0;
     int detail = 0;
     int hash = 0;

     verbose = 1;
     matching = 0;

     while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
 	if (unformat (input, "brief")   ||
 	    unformat (input, "summary") ||
 	    unformat (input, "sum"))
 	    verbose = 0;

 	else if (unformat (input, "detail")   ||
                  unformat (input, "det"))
 	    detail = 1;

 	else if (unformat (input, "hash") ||
                  unformat (input, "mem") ||
                  unformat (input, "memory"))
 	    hash = 1;

 	else if (unformat (input, "%U/%d",
 			   unformat_ip6_address, &matching_address, &mask_len))
 	    matching = 1;

 	else if (unformat (input, "%U", unformat_ip6_address, &matching_address))
 	    matching = 1;

 	else if (unformat (input, "table %d", &table_id))
 	    ;
 	else if (unformat (input, "index %d", &fib_index))
 	    ;
 	else
 	    break;
     }

     if (hash)
     {
         vlib_cli_output (vm, "IPv6 Non-Forwarding Hash Table:\n%U\n",
                          BV (format_bihash),
                          &im6->ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
                          detail);
         vlib_cli_output (vm, "IPv6 Forwarding Hash Table:\n%U\n",
                          BV (format_bihash),
                          &im6->ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash,
                          detail);
         return (NULL);
     }

     pool_foreach (fib_table, im6->fibs,
     ({
         fib_source_t source;
         u8 *s = NULL;

 	fib = pool_elt_at_index(im6->v6_fibs, fib_table->ft_index);
 	if (table_id >= 0 && table_id != (int)fib->table_id)
 	    continue;
 	if (fib_index != ~0 && fib_index != (int)fib->index)
 	    continue;
         if (fib_table->ft_flags & FIB_TABLE_FLAG_IP6_LL)
             continue;

 	s = format(s, "%U, fib_index:%d, flow hash:[%U] epoch:%d flags:%U locks:[",
                    format_fib_table_name, fib->index,
                    FIB_PROTOCOL_IP6,
                    fib->index,
                    format_ip_flow_hash_config,
                    fib_table->ft_flow_hash_config,
                    fib_table->ft_epoch,
                    format_fib_table_flags, fib_table->ft_flags);

         vec_foreach_index(source, fib_table->ft_locks)
         {
             if (0 != fib_table->ft_locks[source])
             {
                 s = format(s, "%U:%d, ",
                            format_fib_source, source,
                            fib_table->ft_locks[source]);
             }
         }
         s = format (s, "]");
         vlib_cli_output (vm, "%v", s);
         vec_free(s);

 	/* Show summary? */
 	if (! verbose)
 	{
 	    clib_bihash_24_8_t * h = &im6->ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash;
 	    int len;

 	    vlib_cli_output (vm, "%=20s%=16s", "Prefix length", "Count");

 	    clib_memset (ca, 0, sizeof(*ca));
 	    ca->fib_index = fib->index;

 	    clib_bihash_foreach_key_value_pair_24_8
 		(h, count_routes_in_fib_at_prefix_length, ca);

 	    for (len = 128; len >= 0; len--)
             {
 		if (ca->count_by_prefix_length[len])
 		    vlib_cli_output (vm, "%=20d%=16lld",
 				     len, ca->count_by_prefix_length[len]);
             }
 	    continue;
 	}

 	if (!matching)
 	{
 	    ip6_fib_table_show_all(fib, vm);
 	}
 	else
 	{
 	    ip6_fib_table_show_one(fib, vm, &matching_address, mask_len, detail);
 	}
     }));

     return 0;
 }

 /*?
  * This command displays the IPv6 FIB Tables (VRF Tables) and the route
  * entries for each table.
  *
  * @note This command will run for a long time when the FIB tables are
  * comprised of millions of entries. For those senarios, consider displaying
  * in summary mode.
  *
  * @cliexpar
  * @parblock
  * Example of how to display all the IPv6 FIB tables:
  * @cliexstart{show ip6 fib}
  * ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
  * @::/0
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:5 buckets:1 uRPF:5 to:[0:0]]
  *     [0] [@0]: dpo-drop ip6
  * fe80::/10
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:10 buckets:1 uRPF:10 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::1/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:8 buckets:1 uRPF:8 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::2/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:7 buckets:1 uRPF:7 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::16/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:9 buckets:1 uRPF:9 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::1:ff00:0/104
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:6 buckets:1 uRPF:6 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ipv6-VRF:8, fib_index 1, flow hash: src dst sport dport proto
  * @::/0
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
  *     [0] [@0]: dpo-drop ip6
  * @::a:1:1:0:4/126
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:27 buckets:1 uRPF:26 to:[0:0]]
  *     [0] [@4]: ipv6-glean: af_packet0
  * @::a:1:1:0:7/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:28 buckets:1 uRPF:27 to:[0:0]]
  *     [0] [@2]: dpo-receive: @::a:1:1:0:7 on af_packet0
  * fe80::/10
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:26 buckets:1 uRPF:25 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * fe80::fe:3eff:fe3e:9222/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:29 buckets:1 uRPF:28 to:[0:0]]
  *     [0] [@2]: dpo-receive: fe80::fe:3eff:fe3e:9222 on af_packet0
  * ff02::1/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:24 buckets:1 uRPF:23 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::2/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:23 buckets:1 uRPF:22 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::16/128
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:25 buckets:1 uRPF:24 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * ff02::1:ff00:0/104
  *   unicast-ip6-chain
  *   [@0]: dpo-load-balance: [index:22 buckets:1 uRPF:21 to:[0:0]]
  *     [0] [@2]: dpo-receive
  * @cliexend
  *
  * Example of how to display a summary of all IPv6 FIB tables:
  * @cliexstart{show ip6 fib summary}
  * ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
  *     Prefix length         Count
  *          128                3
  *          104                1
  *          10                 1
  *           0                 1
  * ipv6-VRF:8, fib_index 1, flow hash: src dst sport dport proto
  *     Prefix length         Count
  *          128                5
  *          126                1
  *          104                1
  *          10                 1
  *           0                 1
  * @cliexend
  * @endparblock
  ?*/
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (ip6_show_fib_command, static) = {
     .path = "show ip6 fib",
     .short_help = "show ip6 fib [summary] [table <table-id>] [index <fib-id>] [<ip6-addr>[/<width>]] [detail]",
     .function = ip6_show_fib,
 };
 /* *INDENT-ON* */
	/*
	* 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/fib/ip6_fib.h>
	#include <vnet/fib/fib_table.h>
	#include <vnet/dpo/ip6_ll_dpo.h>

	#include <vppinfra/bihash_24_8.h>
	#include <vppinfra/bihash_template.c>

	static void
	vnet_ip6_fib_init (u32 fib_index)
	{
	fib_prefix_t pfx = {
	.fp_proto = FIB_PROTOCOL_IP6,
	.fp_len = 0,
	.fp_addr = {
	.ip6 = {
	{ 0, 0, },
	},
	}
	};

	/*
	* Add the default route.
	*/
	fib_table_entry_special_add(fib_index,
	&pfx,
	FIB_SOURCE_DEFAULT_ROUTE,
	FIB_ENTRY_FLAG_DROP);

	/*
	* all link local via the link local lookup DPO
	*/
	pfx.fp_addr.ip6.as_u64[0] = clib_host_to_net_u64 (0xFE80000000000000ULL);
	pfx.fp_addr.ip6.as_u64[1] = 0;
	pfx.fp_len = 10;
	fib_table_entry_special_dpo_add(fib_index,
	&pfx,
	FIB_SOURCE_SPECIAL,
	FIB_ENTRY_FLAG_NONE,
	ip6_ll_dpo_get());
	}

	static u32
	create_fib_with_table_id (u32 table_id,
	fib_source_t src,
	fib_table_flags_t flags,
	u8 *desc)
	{
	fib_table_t *fib_table;
	ip6_fib_t *v6_fib;

	pool_get(ip6_main.fibs, fib_table);
	pool_get_aligned(ip6_main.v6_fibs, v6_fib, CLIB_CACHE_LINE_BYTES);

	clib_memset(fib_table, 0, sizeof(*fib_table));
	clib_memset(v6_fib, 0, sizeof(*v6_fib));

	ASSERT((fib_table - ip6_main.fibs) ==
	(v6_fib - ip6_main.v6_fibs));

	fib_table->ft_proto = FIB_PROTOCOL_IP6;
	fib_table->ft_index =
	v6_fib->index =
	(fib_table - ip6_main.fibs);

	hash_set(ip6_main.fib_index_by_table_id, table_id, fib_table->ft_index);

	fib_table->ft_table_id =
	v6_fib->table_id =
	table_id;
	fib_table->ft_flow_hash_config = IP_FLOW_HASH_DEFAULT;
	fib_table->ft_flags = flags;
	fib_table->ft_desc = desc;

	vnet_ip6_fib_init(fib_table->ft_index);
	fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP6, src);

	return (fib_table->ft_index);
	}

	u32
	ip6_fib_table_find_or_create_and_lock (u32 table_id,
	fib_source_t src)
	{
	uword * p;

	p = hash_get (ip6_main.fib_index_by_table_id, table_id);
	if (NULL == p)
	return create_fib_with_table_id(table_id, src,
	FIB_TABLE_FLAG_NONE,
	NULL);

	fib_table_lock(p[0], FIB_PROTOCOL_IP6, src);

	return (p[0]);
	}

	u32
	ip6_fib_table_create_and_lock (fib_source_t src,
	fib_table_flags_t flags,
	u8 *desc)
	{
	return (create_fib_with_table_id(~0, src, flags, desc));
	}

	void
	ip6_fib_table_destroy (u32 fib_index)
	{
	/*
	* all link local first ...
	*/
	fib_prefix_t pfx = {
	.fp_proto = FIB_PROTOCOL_IP6,
	.fp_len = 10,
	.fp_addr = {
	.ip6 = {
	.as_u8 = {
	[0] = 0xFE,
	[1] = 0x80,
	},
	},
	}
	};
	fib_table_entry_delete(fib_index,
	&pfx,
	FIB_SOURCE_SPECIAL);

	/*
	* ... then the default route.
	*/
	pfx.fp_addr.ip6.as_u64[0] = 0;
	pfx.fp_len = 00;
	fib_table_entry_special_remove(fib_index,
	&pfx,
	FIB_SOURCE_DEFAULT_ROUTE);

	fib_table_t *fib_table = fib_table_get(fib_index, FIB_PROTOCOL_IP6);
	fib_source_t source;

	/*
	* validate no more routes.
	*/
	#if CLIB_DEBUG > 0
	if (0 != fib_table->ft_total_route_counts)
	fib_table_assert_empty(fib_table);
	#endif

	vec_foreach_index(source, fib_table->ft_src_route_counts)
	{
	ASSERT(0 == fib_table->ft_src_route_counts[source]);
	}

	if (~0 != fib_table->ft_table_id)
	{
	hash_unset (ip6_main.fib_index_by_table_id, fib_table->ft_table_id);
	}
	vec_free(fib_table->ft_src_route_counts);
	pool_put_index(ip6_main.v6_fibs, fib_table->ft_index);
	pool_put(ip6_main.fibs, fib_table);
	}

	fib_node_index_t
	ip6_fib_table_lookup (u32 fib_index,
	const ip6_address_t *addr,
	u32 len)
	{
	ip6_fib_table_instance_t *table;
	clib_bihash_kv_24_8_t kv, value;
	int i, n_p, rv;
	u64 fib;

	table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
	n_p = vec_len (table->prefix_lengths_in_search_order);

	kv.key[0] = addr->as_u64[0];
	kv.key[1] = addr->as_u64[1];
	fib = ((u64)((fib_index))<<32);

	/*
	* start search from a mask length same length or shorter.
	* we don't want matches longer than the mask passed
	*/
	i = 0;
	while (i < n_p && table->prefix_lengths_in_search_order[i] > len)
	{
	i++;
	}

	for (; i < n_p; i++)
	{
	int dst_address_length = table->prefix_lengths_in_search_order[i];
	ip6_address_t * mask = &ip6_main.fib_masks[dst_address_length];

	ASSERT(dst_address_length >= 0 && dst_address_length <= 128);
	//As lengths are decreasing, masks are increasingly specific.
	kv.key[0] &= mask->as_u64[0];
	kv.key[1] &= mask->as_u64[1];
	kv.key[2] = fib \| dst_address_length;

	rv = clib_bihash_search_inline_2_24_8(&table->ip6_hash, &kv, &value);
	if (rv == 0)
	return value.value;
	}

	return (FIB_NODE_INDEX_INVALID);
	}

	fib_node_index_t
	ip6_fib_table_lookup_exact_match (u32 fib_index,
	const ip6_address_t *addr,
	u32 len)
	{
	ip6_fib_table_instance_t *table;
	clib_bihash_kv_24_8_t kv, value;
	ip6_address_t *mask;
	u64 fib;
	int rv;

	table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
	mask = &ip6_main.fib_masks[len];
	fib = ((u64)((fib_index))<<32);

	kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
	kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
	kv.key[2] = fib \| len;

	rv = clib_bihash_search_inline_2_24_8(&table->ip6_hash, &kv, &value);
	if (rv == 0)
	return value.value;

	return (FIB_NODE_INDEX_INVALID);
	}

	static void
	compute_prefix_lengths_in_search_order (ip6_fib_table_instance_t *table)
	{
	u8 old, prefix_lengths_in_search_order = NULL;
	int i;

	/*
	* build the list in a scratch space then cutover so the workers
	* can continue uninterrupted.
	*/
	old = table->prefix_lengths_in_search_order;

	/* Note: bitmap reversed so this is in fact a longest prefix match */
	clib_bitmap_foreach (i, table->non_empty_dst_address_length_bitmap,
	({
	int dst_address_length = 128 - i;
	vec_add1(prefix_lengths_in_search_order, dst_address_length);
	}));

	table->prefix_lengths_in_search_order = prefix_lengths_in_search_order;

	/*
	* let the workers go once round the track before we free the old set
	*/
	vlib_worker_wait_one_loop();
	vec_free(old);
	}

	void
	ip6_fib_table_entry_remove (u32 fib_index,
	const ip6_address_t *addr,
	u32 len)
	{
	ip6_fib_table_instance_t *table;
	clib_bihash_kv_24_8_t kv;
	ip6_address_t *mask;
	u64 fib;

	table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
	mask = &ip6_main.fib_masks[len];
	fib = ((u64)((fib_index))<<32);

	kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
	kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
	kv.key[2] = fib \| len;

	clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 0);

	/* refcount accounting */
	ASSERT (table->dst_address_length_refcounts[len] > 0);
	if (--table->dst_address_length_refcounts[len] == 0)
	{
	table->non_empty_dst_address_length_bitmap =
	clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
	128 - len, 0);
	compute_prefix_lengths_in_search_order (table);
	}
	}

	void
	ip6_fib_table_entry_insert (u32 fib_index,
	const ip6_address_t *addr,
	u32 len,
	fib_node_index_t fib_entry_index)
	{
	ip6_fib_table_instance_t *table;
	clib_bihash_kv_24_8_t kv;
	ip6_address_t *mask;
	u64 fib;

	table = &ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING];
	mask = &ip6_main.fib_masks[len];
	fib = ((u64)((fib_index))<<32);

	kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
	kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
	kv.key[2] = fib \| len;
	kv.value = fib_entry_index;

	clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 1);

	if (0 == table->dst_address_length_refcounts[len]++)
	{
	table->non_empty_dst_address_length_bitmap =
	clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
	128 - len, 1);
	compute_prefix_lengths_in_search_order (table);
	}
	}

	u32 ip6_fib_table_fwding_lookup_with_if_index (ip6_main_t * im,
	u32 sw_if_index,
	const ip6_address_t * dst)
	{
	u32 fib_index = vec_elt (im->fib_index_by_sw_if_index, sw_if_index);
	return ip6_fib_table_fwding_lookup(fib_index, dst);
	}

	u32
	ip6_fib_table_get_index_for_sw_if_index (u32 sw_if_index)
	{
	if (sw_if_index >= vec_len(ip6_main.fib_index_by_sw_if_index))
	{
	/*
	* This is the case for interfaces that are not yet mapped to
	* a IP table
	*/
	return (~0);
	}
	return (ip6_main.fib_index_by_sw_if_index[sw_if_index]);
	}

	void
	ip6_fib_table_fwding_dpo_update (u32 fib_index,
	const ip6_address_t *addr,
	u32 len,
	const dpo_id_t *dpo)
	{
	ip6_fib_table_instance_t *table;
	clib_bihash_kv_24_8_t kv;
	ip6_address_t *mask;
	u64 fib;

	table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
	mask = &ip6_main.fib_masks[len];
	fib = ((u64)((fib_index))<<32);

	kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
	kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
	kv.key[2] = fib \| len;
	kv.value = dpo->dpoi_index;

	clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 1);

	if (0 == table->dst_address_length_refcounts[len]++)
	{
	table->non_empty_dst_address_length_bitmap =
	clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
	128 - len, 1);
	compute_prefix_lengths_in_search_order (table);
	}
	}

	void
	ip6_fib_table_fwding_dpo_remove (u32 fib_index,
	const ip6_address_t *addr,
	u32 len,
	const dpo_id_t *dpo)
	{
	ip6_fib_table_instance_t *table;
	clib_bihash_kv_24_8_t kv;
	ip6_address_t *mask;
	u64 fib;

	table = &ip6_main.ip6_table[IP6_FIB_TABLE_FWDING];
	mask = &ip6_main.fib_masks[len];
	fib = ((u64)((fib_index))<<32);

	kv.key[0] = addr->as_u64[0] & mask->as_u64[0];
	kv.key[1] = addr->as_u64[1] & mask->as_u64[1];
	kv.key[2] = fib \| len;
	kv.value = dpo->dpoi_index;

	clib_bihash_add_del_24_8(&table->ip6_hash, &kv, 0);

	/* refcount accounting */
	ASSERT (table->dst_address_length_refcounts[len] > 0);
	if (--table->dst_address_length_refcounts[len] == 0)
	{
	table->non_empty_dst_address_length_bitmap =
	clib_bitmap_set (table->non_empty_dst_address_length_bitmap,
	128 - len, 0);
	compute_prefix_lengths_in_search_order (table);
	}
	}

	/**
	* @brief Context when walking the IPv6 table. Since all VRFs are in the
	* same hash table, we need to filter only those we need as we walk
	*/
	typedef struct ip6_fib_walk_ctx_t_
	{
	u32 i6w_fib_index;
	fib_table_walk_fn_t i6w_fn;
	void *i6w_ctx;
	fib_prefix_t i6w_root;
	fib_prefix_t *i6w_sub_trees;
	} ip6_fib_walk_ctx_t;

	static int
	ip6_fib_walk_cb (clib_bihash_kv_24_8_t * kvp,
	void *arg)
	{
	ip6_fib_walk_ctx_t *ctx = arg;
	ip6_address_t key;

	if ((kvp->key[2] >> 32) == ctx->i6w_fib_index)
	{
	key.as_u64[0] = kvp->key[0];
	key.as_u64[1] = kvp->key[1];

	if (ip6_destination_matches_route(&ip6_main,
	&key,
	&ctx->i6w_root.fp_addr.ip6,
	ctx->i6w_root.fp_len))
	{
	const fib_prefix_t *sub_tree;
	int skip = 0;

	/*
	* exclude sub-trees the walk does not want to explore
	*/
	vec_foreach(sub_tree, ctx->i6w_sub_trees)
	{
	if (ip6_destination_matches_route(&ip6_main,
	&key,
	&sub_tree->fp_addr.ip6,
	sub_tree->fp_len))
	{
	skip = 1;
	break;
	}
	}

	if (!skip)
	{
	switch (ctx->i6w_fn(kvp->value, ctx->i6w_ctx))
	{
	case FIB_TABLE_WALK_CONTINUE:
	break;
	case FIB_TABLE_WALK_SUB_TREE_STOP: {
	fib_prefix_t pfx = {
	.fp_proto = FIB_PROTOCOL_IP6,
	.fp_len = kvp->key[2] & 0xffffffff,
	.fp_addr.ip6 = key,
	};
	vec_add1(ctx->i6w_sub_trees, pfx);
	break;
	}
	case FIB_TABLE_WALK_STOP:
	goto done;
	}
	}
	}
	}
	done:

	return (1);
	}

	void
	ip6_fib_table_walk (u32 fib_index,
	fib_table_walk_fn_t fn,
	void *arg)
	{
	ip6_fib_walk_ctx_t ctx = {
	.i6w_fib_index = fib_index,
	.i6w_fn = fn,
	.i6w_ctx = arg,
	.i6w_root = {
	.fp_proto = FIB_PROTOCOL_IP6,
	},
	.i6w_sub_trees = NULL,
	};

	clib_bihash_foreach_key_value_pair_24_8(
	&ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
	ip6_fib_walk_cb,
	&ctx);

	vec_free(ctx.i6w_sub_trees);
	}

	void
	ip6_fib_table_sub_tree_walk (u32 fib_index,
	const fib_prefix_t *root,
	fib_table_walk_fn_t fn,
	void *arg)
	{
	ip6_fib_walk_ctx_t ctx = {
	.i6w_fib_index = fib_index,
	.i6w_fn = fn,
	.i6w_ctx = arg,
	.i6w_root = *root,
	};

	clib_bihash_foreach_key_value_pair_24_8(
	&ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
	ip6_fib_walk_cb,
	&ctx);
	}

	typedef struct ip6_fib_show_ctx_t_ {
	fib_node_index_t *entries;
	} ip6_fib_show_ctx_t;

	static fib_table_walk_rc_t
	ip6_fib_table_show_walk (fib_node_index_t fib_entry_index,
	void *arg)
	{
	ip6_fib_show_ctx_t *ctx = arg;

	vec_add1(ctx->entries, fib_entry_index);

	return (FIB_TABLE_WALK_CONTINUE);
	}

	static void
	ip6_fib_table_show_all (ip6_fib_t *fib,
	vlib_main_t * vm)
	{
	fib_node_index_t *fib_entry_index;
	ip6_fib_show_ctx_t ctx = {
	.entries = NULL,
	};

	ip6_fib_table_walk(fib->index, ip6_fib_table_show_walk, &ctx);
	vec_sort_with_function(ctx.entries, fib_entry_cmp_for_sort);

	vec_foreach(fib_entry_index, ctx.entries)
	{
	vlib_cli_output(vm, "%U",
	format_fib_entry,
	*fib_entry_index,
	FIB_ENTRY_FORMAT_BRIEF);
	}

	vec_free(ctx.entries);
	}

	static void
	ip6_fib_table_show_one (ip6_fib_t *fib,
	vlib_main_t * vm,
	ip6_address_t *address,
	u32 mask_len,
	int detail)
	{
	vlib_cli_output(vm, "%U",
	format_fib_entry,
	ip6_fib_table_lookup(fib->index, address, mask_len),
	(detail ?
	FIB_ENTRY_FORMAT_DETAIL2:
	FIB_ENTRY_FORMAT_DETAIL));
	}

	u8 *
	format_ip6_fib_table_memory (u8 * s, va_list * args)
	{
	uword bytes_inuse;

	bytes_inuse = (alloc_arena_next(&(ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash)) +
	alloc_arena_next(&(ip6_main.ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash)));

	s = format(s, "%=30s %=6d %=12ld\n",
	"IPv6 unicast",
	pool_elts(ip6_main.fibs),
	bytes_inuse);
	return (s);
	}

	typedef struct {
	u32 fib_index;
	u64 count_by_prefix_length[129];
	} count_routes_in_fib_at_prefix_length_arg_t;

	static int
	count_routes_in_fib_at_prefix_length (clib_bihash_kv_24_8_t * kvp,
	void *arg)
	{
	count_routes_in_fib_at_prefix_length_arg_t * ap = arg;
	int mask_width;

	if ((kvp->key[2]>>32) != ap->fib_index)
	return (BIHASH_WALK_CONTINUE);

	mask_width = kvp->key[2] & 0xFF;

	ap->count_by_prefix_length[mask_width]++;

	return (BIHASH_WALK_CONTINUE);
	}

	static clib_error_t *
	ip6_show_fib (vlib_main_t * vm,
	unformat_input_t * input,
	vlib_cli_command_t * cmd)
	{
	count_routes_in_fib_at_prefix_length_arg_t _ca, *ca = &_ca;
	ip6_main_t * im6 = &ip6_main;
	fib_table_t *fib_table;
	ip6_fib_t * fib;
	int verbose, matching;
	ip6_address_t matching_address;
	u32 mask_len = 128;
	int table_id = -1, fib_index = ~0;
	int detail = 0;
	int hash = 0;

	verbose = 1;
	matching = 0;

	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	if (unformat (input, "brief") \|\|
	unformat (input, "summary") \|\|
	unformat (input, "sum"))
	verbose = 0;

	else if (unformat (input, "detail") \|\|
	unformat (input, "det"))
	detail = 1;

	else if (unformat (input, "hash") \|\|
	unformat (input, "mem") \|\|
	unformat (input, "memory"))
	hash = 1;

	else if (unformat (input, "%U/%d",
	unformat_ip6_address, &matching_address, &mask_len))
	matching = 1;

	else if (unformat (input, "%U", unformat_ip6_address, &matching_address))
	matching = 1;

	else if (unformat (input, "table %d", &table_id))
	;
	else if (unformat (input, "index %d", &fib_index))
	;
	else
	break;
	}

	if (hash)
	{
	vlib_cli_output (vm, "IPv6 Non-Forwarding Hash Table:\n%U\n",
	BV (format_bihash),
	&im6->ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash,
	detail);
	vlib_cli_output (vm, "IPv6 Forwarding Hash Table:\n%U\n",
	BV (format_bihash),
	&im6->ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash,
	detail);
	return (NULL);
	}

	pool_foreach (fib_table, im6->fibs,
	({
	fib_source_t source;
	u8 *s = NULL;

	fib = pool_elt_at_index(im6->v6_fibs, fib_table->ft_index);
	if (table_id >= 0 && table_id != (int)fib->table_id)
	continue;
	if (fib_index != ~0 && fib_index != (int)fib->index)
	continue;
	if (fib_table->ft_flags & FIB_TABLE_FLAG_IP6_LL)
	continue;

	s = format(s, "%U, fib_index:%d, flow hash:[%U] epoch:%d flags:%U locks:[",
	format_fib_table_name, fib->index,
	FIB_PROTOCOL_IP6,
	fib->index,
	format_ip_flow_hash_config,
	fib_table->ft_flow_hash_config,
	fib_table->ft_epoch,
	format_fib_table_flags, fib_table->ft_flags);

	vec_foreach_index(source, fib_table->ft_locks)
	{
	if (0 != fib_table->ft_locks[source])
	{
	s = format(s, "%U:%d, ",
	format_fib_source, source,
	fib_table->ft_locks[source]);
	}
	}
	s = format (s, "]");
	vlib_cli_output (vm, "%v", s);
	vec_free(s);

	/* Show summary? */
	if (! verbose)
	{
	clib_bihash_24_8_t * h = &im6->ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash;
	int len;

	vlib_cli_output (vm, "%=20s%=16s", "Prefix length", "Count");

	clib_memset (ca, 0, sizeof(*ca));
	ca->fib_index = fib->index;

	clib_bihash_foreach_key_value_pair_24_8
	(h, count_routes_in_fib_at_prefix_length, ca);

	for (len = 128; len >= 0; len--)
	{
	if (ca->count_by_prefix_length[len])
	vlib_cli_output (vm, "%=20d%=16lld",
	len, ca->count_by_prefix_length[len]);
	}
	continue;
	}

	if (!matching)
	{
	ip6_fib_table_show_all(fib, vm);
	}
	else
	{
	ip6_fib_table_show_one(fib, vm, &matching_address, mask_len, detail);
	}
	}));

	return 0;
	}

	/*?
	* This command displays the IPv6 FIB Tables (VRF Tables) and the route
	* entries for each table.
	*
	* @note This command will run for a long time when the FIB tables are
	* comprised of millions of entries. For those senarios, consider displaying
	* in summary mode.
	*
	* @cliexpar
	* @parblock
	* Example of how to display all the IPv6 FIB tables:
	* @cliexstart{show ip6 fib}
	* ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
	* @::/0
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:5 buckets:1 uRPF:5 to:[0:0]]
	* [0] [@0]: dpo-drop ip6
	* fe80::/10
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:10 buckets:1 uRPF:10 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::1/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:8 buckets:1 uRPF:8 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::2/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:7 buckets:1 uRPF:7 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::16/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:9 buckets:1 uRPF:9 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::1:ff00:0/104
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:6 buckets:1 uRPF:6 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ipv6-VRF:8, fib_index 1, flow hash: src dst sport dport proto
	* @::/0
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
	* [0] [@0]: dpo-drop ip6
	* @::a:1:1:0:4/126
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:27 buckets:1 uRPF:26 to:[0:0]]
	* [0] [@4]: ipv6-glean: af_packet0
	* @::a:1:1:0:7/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:28 buckets:1 uRPF:27 to:[0:0]]
	* [0] [@2]: dpo-receive: @::a:1:1:0:7 on af_packet0
	* fe80::/10
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:26 buckets:1 uRPF:25 to:[0:0]]
	* [0] [@2]: dpo-receive
	* fe80::fe:3eff:fe3e:9222/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:29 buckets:1 uRPF:28 to:[0:0]]
	* [0] [@2]: dpo-receive: fe80::fe:3eff:fe3e:9222 on af_packet0
	* ff02::1/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:24 buckets:1 uRPF:23 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::2/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:23 buckets:1 uRPF:22 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::16/128
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:25 buckets:1 uRPF:24 to:[0:0]]
	* [0] [@2]: dpo-receive
	* ff02::1:ff00:0/104
	* unicast-ip6-chain
	* [@0]: dpo-load-balance: [index:22 buckets:1 uRPF:21 to:[0:0]]
	* [0] [@2]: dpo-receive
	* @cliexend
	*
	* Example of how to display a summary of all IPv6 FIB tables:
	* @cliexstart{show ip6 fib summary}
	* ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
	* Prefix length Count
	* 128 3
	* 104 1
	* 10 1
	* 0 1
	* ipv6-VRF:8, fib_index 1, flow hash: src dst sport dport proto
	* Prefix length Count
	* 128 5
	* 126 1
	* 104 1
	* 10 1
	* 0 1
	* @cliexend
	* @endparblock
	?*/
	/* INDENT-OFF */
	VLIB_CLI_COMMAND (ip6_show_fib_command, static) = {
	.path = "show ip6 fib",
	.short_help = "show ip6 fib [summary] [table <table-id>] [index <fib-id>] [<ip6-addr>[/<width>]] [detail]",
	.function = ip6_show_fib,
	};
	/* INDENT-ON */