diff options
Diffstat (limited to 'net/netfilter/nft_hash.c')
-rw-r--r-- | net/netfilter/nft_hash.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c new file mode 100644 index 0000000..3d3f8fc --- /dev/null +++ b/net/netfilter/nft_hash.c @@ -0,0 +1,231 @@ +/* + * Copyright (c) 2008-2009 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/jhash.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> + +struct nft_hash { + struct hlist_head *hash; + unsigned int hsize; +}; + +struct nft_hash_elem { + struct hlist_node hnode; + struct nft_data key; + struct nft_data data[]; +}; + +static u32 nft_hash_rnd __read_mostly; +static bool nft_hash_rnd_initted __read_mostly; + +static unsigned int nft_hash_data(const struct nft_data *data, + unsigned int hsize, unsigned int len) +{ + unsigned int h; + + h = jhash(data->data, len, nft_hash_rnd); + return ((u64)h * hsize) >> 32; +} + +static bool nft_hash_lookup(const struct nft_set *set, + const struct nft_data *key, + struct nft_data *data) +{ + const struct nft_hash *priv = nft_set_priv(set); + const struct nft_hash_elem *he; + unsigned int h; + + h = nft_hash_data(key, priv->hsize, set->klen); + hlist_for_each_entry(he, &priv->hash[h], hnode) { + if (nft_data_cmp(&he->key, key, set->klen)) + continue; + if (set->flags & NFT_SET_MAP) + nft_data_copy(data, he->data); + return true; + } + return false; +} + +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 int nft_hash_insert(const struct nft_set *set, + const struct nft_set_elem *elem) +{ + struct nft_hash *priv = nft_set_priv(set); + struct nft_hash_elem *he; + unsigned int size, h; + + 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); + + h = nft_hash_data(&he->key, priv->hsize, set->klen); + hlist_add_head_rcu(&he->hnode, &priv->hash[h]); + return 0; +} + +static void nft_hash_remove(const struct nft_set *set, + const struct nft_set_elem *elem) +{ + struct nft_hash_elem *he = elem->cookie; + + hlist_del_rcu(&he->hnode); + kfree(he); +} + +static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem) +{ + const struct nft_hash *priv = nft_set_priv(set); + struct nft_hash_elem *he; + unsigned int h; + + h = nft_hash_data(&elem->key, priv->hsize, set->klen); + hlist_for_each_entry(he, &priv->hash[h], hnode) { + if (nft_data_cmp(&he->key, &elem->key, set->klen)) + continue; + + elem->cookie = he; + elem->flags = 0; + if (set->flags & NFT_SET_MAP) + nft_data_copy(&elem->data, he->data); + return 0; + } + return -ENOENT; +} + +static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set, + struct nft_set_iter *iter) +{ + const struct nft_hash *priv = nft_set_priv(set); + const struct nft_hash_elem *he; + struct nft_set_elem elem; + unsigned int i; + + for (i = 0; i < priv->hsize; i++) { + hlist_for_each_entry(he, &priv->hash[i], hnode) { + 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) + return; +cont: + iter->count++; + } + } +} + +static unsigned int nft_hash_privsize(const struct nlattr * const nla[]) +{ + return sizeof(struct nft_hash); +} + +static int nft_hash_init(const struct nft_set *set, + const struct nlattr * const tb[]) +{ + struct nft_hash *priv = nft_set_priv(set); + unsigned int cnt, i; + + if (unlikely(!nft_hash_rnd_initted)) { + get_random_bytes(&nft_hash_rnd, 4); + nft_hash_rnd_initted = true; + } + + /* Aim for a load factor of 0.75 */ + // FIXME: temporarily broken until we have set descriptions + cnt = 100; + cnt = cnt * 4 / 3; + + priv->hash = kcalloc(cnt, sizeof(struct hlist_head), GFP_KERNEL); + if (priv->hash == NULL) + return -ENOMEM; + priv->hsize = cnt; + + for (i = 0; i < cnt; i++) + INIT_HLIST_HEAD(&priv->hash[i]); + + return 0; +} + +static void nft_hash_destroy(const struct nft_set *set) +{ + const struct nft_hash *priv = nft_set_priv(set); + const struct hlist_node *next; + struct nft_hash_elem *elem; + unsigned int i; + + for (i = 0; i < priv->hsize; i++) { + hlist_for_each_entry_safe(elem, next, &priv->hash[i], hnode) { + hlist_del(&elem->hnode); + nft_hash_elem_destroy(set, elem); + } + } + kfree(priv->hash); +} + +static struct nft_set_ops nft_hash_ops __read_mostly = { + .privsize = nft_hash_privsize, + .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(); |