![Daniel Borkmann](/assets/img/avatar_default.png)
Currently, all real users of rhashtable default their grow and shrink decision functions to rht_grow_above_75() and rht_shrink_below_30(), so that there's currently no need to have this explicitly selectable. It can/should be generic and private inside rhashtable until a real use case pops up. Since we can make this private, we'll save us this additional indirection layer and can improve insertion/deletion time as well. Reference: http://patchwork.ozlabs.org/patch/443040/ Suggested-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
280 lines
6.4 KiB
C
280 lines
6.4 KiB
C
/*
|
|
* Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Development of this code funded by Astaro AG (http://www.astaro.com/)
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/list.h>
|
|
#include <linux/log2.h>
|
|
#include <linux/jhash.h>
|
|
#include <linux/netlink.h>
|
|
#include <linux/rhashtable.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/netfilter/nf_tables.h>
|
|
#include <net/netfilter/nf_tables.h>
|
|
|
|
/* We target a hash table size of 4, element hint is 75% of final size */
|
|
#define NFT_HASH_ELEMENT_HINT 3
|
|
|
|
struct nft_hash_elem {
|
|
struct rhash_head node;
|
|
struct nft_data key;
|
|
struct nft_data data[];
|
|
};
|
|
|
|
static bool nft_hash_lookup(const struct nft_set *set,
|
|
const struct nft_data *key,
|
|
struct nft_data *data)
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
const struct nft_hash_elem *he;
|
|
|
|
he = rhashtable_lookup(priv, key);
|
|
if (he && set->flags & NFT_SET_MAP)
|
|
nft_data_copy(data, he->data);
|
|
|
|
return !!he;
|
|
}
|
|
|
|
static int nft_hash_insert(const struct nft_set *set,
|
|
const struct nft_set_elem *elem)
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
struct nft_hash_elem *he;
|
|
unsigned int size;
|
|
|
|
if (elem->flags != 0)
|
|
return -EINVAL;
|
|
|
|
size = sizeof(*he);
|
|
if (set->flags & NFT_SET_MAP)
|
|
size += sizeof(he->data[0]);
|
|
|
|
he = kzalloc(size, GFP_KERNEL);
|
|
if (he == NULL)
|
|
return -ENOMEM;
|
|
|
|
nft_data_copy(&he->key, &elem->key);
|
|
if (set->flags & NFT_SET_MAP)
|
|
nft_data_copy(he->data, &elem->data);
|
|
|
|
rhashtable_insert(priv, &he->node);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void nft_hash_elem_destroy(const struct nft_set *set,
|
|
struct nft_hash_elem *he)
|
|
{
|
|
nft_data_uninit(&he->key, NFT_DATA_VALUE);
|
|
if (set->flags & NFT_SET_MAP)
|
|
nft_data_uninit(he->data, set->dtype);
|
|
kfree(he);
|
|
}
|
|
|
|
static void nft_hash_remove(const struct nft_set *set,
|
|
const struct nft_set_elem *elem)
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
|
|
rhashtable_remove(priv, elem->cookie);
|
|
synchronize_rcu();
|
|
kfree(elem->cookie);
|
|
}
|
|
|
|
struct nft_compare_arg {
|
|
const struct nft_set *set;
|
|
struct nft_set_elem *elem;
|
|
};
|
|
|
|
static bool nft_hash_compare(void *ptr, void *arg)
|
|
{
|
|
struct nft_hash_elem *he = ptr;
|
|
struct nft_compare_arg *x = arg;
|
|
|
|
if (!nft_data_cmp(&he->key, &x->elem->key, x->set->klen)) {
|
|
x->elem->cookie = he;
|
|
x->elem->flags = 0;
|
|
if (x->set->flags & NFT_SET_MAP)
|
|
nft_data_copy(&x->elem->data, he->data);
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
struct nft_compare_arg arg = {
|
|
.set = set,
|
|
.elem = elem,
|
|
};
|
|
|
|
if (rhashtable_lookup_compare(priv, &elem->key,
|
|
&nft_hash_compare, &arg))
|
|
return 0;
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
|
|
struct nft_set_iter *iter)
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
const struct nft_hash_elem *he;
|
|
struct rhashtable_iter hti;
|
|
struct nft_set_elem elem;
|
|
int err;
|
|
|
|
err = rhashtable_walk_init(priv, &hti);
|
|
iter->err = err;
|
|
if (err)
|
|
return;
|
|
|
|
err = rhashtable_walk_start(&hti);
|
|
if (err && err != -EAGAIN) {
|
|
iter->err = err;
|
|
goto out;
|
|
}
|
|
|
|
while ((he = rhashtable_walk_next(&hti))) {
|
|
if (IS_ERR(he)) {
|
|
err = PTR_ERR(he);
|
|
if (err != -EAGAIN) {
|
|
iter->err = err;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (iter->count < iter->skip)
|
|
goto cont;
|
|
|
|
memcpy(&elem.key, &he->key, sizeof(elem.key));
|
|
if (set->flags & NFT_SET_MAP)
|
|
memcpy(&elem.data, he->data, sizeof(elem.data));
|
|
elem.flags = 0;
|
|
|
|
iter->err = iter->fn(ctx, set, iter, &elem);
|
|
if (iter->err < 0)
|
|
goto out;
|
|
|
|
cont:
|
|
iter->count++;
|
|
}
|
|
|
|
out:
|
|
rhashtable_walk_stop(&hti);
|
|
rhashtable_walk_exit(&hti);
|
|
}
|
|
|
|
static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
|
|
{
|
|
return sizeof(struct rhashtable);
|
|
}
|
|
|
|
static int nft_hash_init(const struct nft_set *set,
|
|
const struct nft_set_desc *desc,
|
|
const struct nlattr * const tb[])
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
struct rhashtable_params params = {
|
|
.nelem_hint = desc->size ? : NFT_HASH_ELEMENT_HINT,
|
|
.head_offset = offsetof(struct nft_hash_elem, node),
|
|
.key_offset = offsetof(struct nft_hash_elem, key),
|
|
.key_len = set->klen,
|
|
.hashfn = jhash,
|
|
};
|
|
|
|
return rhashtable_init(priv, ¶ms);
|
|
}
|
|
|
|
static void nft_hash_destroy(const struct nft_set *set)
|
|
{
|
|
struct rhashtable *priv = nft_set_priv(set);
|
|
const struct bucket_table *tbl;
|
|
struct nft_hash_elem *he;
|
|
struct rhash_head *pos, *next;
|
|
unsigned int i;
|
|
|
|
/* Stop an eventual async resizing */
|
|
priv->being_destroyed = true;
|
|
mutex_lock(&priv->mutex);
|
|
|
|
tbl = rht_dereference(priv->tbl, priv);
|
|
for (i = 0; i < tbl->size; i++) {
|
|
rht_for_each_entry_safe(he, pos, next, tbl, i, node)
|
|
nft_hash_elem_destroy(set, he);
|
|
}
|
|
mutex_unlock(&priv->mutex);
|
|
|
|
rhashtable_destroy(priv);
|
|
}
|
|
|
|
static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
|
|
struct nft_set_estimate *est)
|
|
{
|
|
unsigned int esize;
|
|
|
|
esize = sizeof(struct nft_hash_elem);
|
|
if (features & NFT_SET_MAP)
|
|
esize += FIELD_SIZEOF(struct nft_hash_elem, data[0]);
|
|
|
|
if (desc->size) {
|
|
est->size = sizeof(struct rhashtable) +
|
|
roundup_pow_of_two(desc->size * 4 / 3) *
|
|
sizeof(struct nft_hash_elem *) +
|
|
desc->size * esize;
|
|
} else {
|
|
/* Resizing happens when the load drops below 30% or goes
|
|
* above 75%. The average of 52.5% load (approximated by 50%)
|
|
* is used for the size estimation of the hash buckets,
|
|
* meaning we calculate two buckets per element.
|
|
*/
|
|
est->size = esize + 2 * sizeof(struct nft_hash_elem *);
|
|
}
|
|
|
|
est->class = NFT_SET_CLASS_O_1;
|
|
|
|
return true;
|
|
}
|
|
|
|
static struct nft_set_ops nft_hash_ops __read_mostly = {
|
|
.privsize = nft_hash_privsize,
|
|
.estimate = nft_hash_estimate,
|
|
.init = nft_hash_init,
|
|
.destroy = nft_hash_destroy,
|
|
.get = nft_hash_get,
|
|
.insert = nft_hash_insert,
|
|
.remove = nft_hash_remove,
|
|
.lookup = nft_hash_lookup,
|
|
.walk = nft_hash_walk,
|
|
.features = NFT_SET_MAP,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init nft_hash_module_init(void)
|
|
{
|
|
return nft_register_set(&nft_hash_ops);
|
|
}
|
|
|
|
static void __exit nft_hash_module_exit(void)
|
|
{
|
|
nft_unregister_set(&nft_hash_ops);
|
|
}
|
|
|
|
module_init(nft_hash_module_init);
|
|
module_exit(nft_hash_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
|
MODULE_ALIAS_NFT_SET();
|