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/*
* 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/fib_table.h>
#include <vnet/fib/fib_entry.h>
#include <vnet/fib/ip4_fib.h>
/*
* ip4_fib_hash_table_lookup_exact_match
*
* Exact match prefix lookup
*/
fib_node_index_t
ip4_fib_hash_table_lookup_exact_match (const ip4_fib_hash_t *fib,
const ip4_address_t *addr,
u32 len)
{
uword * hash, * result;
u32 key;
hash = fib->fib_entry_by_dst_address[len];
key = (addr->data_u32 & ip4_main.fib_masks[len]);
result = hash_get(hash, key);
if (NULL != result) {
return (result[0]);
}
return (FIB_NODE_INDEX_INVALID);
}
/*
* ip4_fib_hash_table_lookup_adj
*
* Longest prefix match
*/
index_t
ip4_fib_hash_table_lookup_lb (const ip4_fib_hash_t *fib,
const ip4_address_t *addr)
{
fib_node_index_t fei;
fei = ip4_fib_hash_table_lookup(fib, addr, 32);
if (FIB_NODE_INDEX_INVALID != fei)
{
const dpo_id_t *dpo;
dpo = fib_entry_contribute_ip_forwarding(fei);
return (dpo->dpoi_index);
}
return (INDEX_INVALID);
}
/*
* ip4_fib_hash_table_lookup
*
* Longest prefix match
*/
fib_node_index_t
ip4_fib_hash_table_lookup (const ip4_fib_hash_t *fib,
const ip4_address_t *addr,
u32 len)
{
uword * hash, * result;
i32 mask_len;
u32 key;
for (mask_len = len; mask_len >= 0; mask_len--)
{
hash = fib->fib_entry_by_dst_address[mask_len];
key = (addr->data_u32 & ip4_main.fib_masks[mask_len]);
result = hash_get (hash, key);
if (NULL != result) {
return (result[0]);
}
}
return (FIB_NODE_INDEX_INVALID);
}
void
ip4_fib_hash_table_entry_insert (ip4_fib_hash_t *fib,
const ip4_address_t *addr,
u32 len,
fib_node_index_t fib_entry_index)
{
uword * hash, * result;
u32 key;
key = (addr->data_u32 & ip4_main.fib_masks[len]);
hash = fib->fib_entry_by_dst_address[len];
result = hash_get (hash, key);
if (NULL == result) {
/*
* adding a new entry
*/
if (NULL == hash) {
hash = hash_create (32 /* elts */, sizeof (uword));
hash_set_flags (hash, HASH_FLAG_NO_AUTO_SHRINK);
}
hash = hash_set(hash, key, fib_entry_index);
fib->fib_entry_by_dst_address[len] = hash;
}
else
{
ASSERT(0);
}
}
void
ip4_fib_hash_table_entry_remove (ip4_fib_hash_t *fib,
const ip4_address_t *addr,
u32 len)
{
uword * hash, * result;
u32 key;
key = (addr->data_u32 & ip4_main.fib_masks[len]);
hash = fib->fib_entry_by_dst_address[len];
result = hash_get (hash, key);
if (NULL == result)
{
/*
* removing a non-existent entry. i'll allow it.
*/
}
else
{
hash_unset(hash, key);
}
fib->fib_entry_by_dst_address[len] = hash;
}
void
ip4_fib_hash_table_walk (ip4_fib_hash_t *fib,
fib_table_walk_fn_t fn,
void *ctx)
{
fib_prefix_t root = {
.fp_proto = FIB_PROTOCOL_IP4,
// address and length default to all 0
};
/*
* A full tree walk is the dengenerate case of a sub-tree from
* the very root
*/
return (ip4_fib_hash_table_sub_tree_walk(fib, &root, fn, ctx));
}
void
ip4_fib_hash_table_sub_tree_walk (ip4_fib_hash_t *fib,
const fib_prefix_t *root,
fib_table_walk_fn_t fn,
void *ctx)
{
fib_prefix_t *sub_trees = NULL;
int i;
/*
* There is no efficient way to walk this array of hash tables.
* so we walk each table with a mask length greater than and equal to
* the required root and check it is covered by the root.
*/
for (i = root->fp_len;
i < ARRAY_LEN (fib->fib_entry_by_dst_address);
i++)
{
uword * hash = fib->fib_entry_by_dst_address[i];
if (NULL != hash)
{
ip4_address_t key;
hash_pair_t * p;
hash_foreach_pair (p, hash,
({
key.as_u32 = p->key;
if (ip4_destination_matches_route(&ip4_main,
&key,
&root->fp_addr.ip4,
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, sub_trees)
{
if (ip4_destination_matches_route(&ip4_main,
&key,
&sub_tree->fp_addr.ip4,
sub_tree->fp_len))
{
skip = 1;
break;
}
}
if (!skip)
{
switch (fn(p->value[0], ctx))
{
case FIB_TABLE_WALK_CONTINUE:
break;
case FIB_TABLE_WALK_SUB_TREE_STOP: {
fib_prefix_t pfx = {
.fp_proto = FIB_PROTOCOL_IP4,
.fp_len = i,
.fp_addr.ip4 = key,
};
vec_add1(sub_trees, pfx);
break;
}
case FIB_TABLE_WALK_STOP:
goto done;
}
}
}
}));
}
}
done:
vec_free(sub_trees);
return;
}
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