2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/list.h>
15 #include <linux/jhash.h>
16 #include <linux/netlink.h>
17 #include <linux/netfilter.h>
18 #include <linux/netfilter/nf_tables.h>
19 #include <net/netfilter/nf_tables.h>
22 struct hlist_head *hash;
26 struct nft_hash_elem {
27 struct hlist_node hnode;
29 struct nft_data data[];
32 static u32 nft_hash_rnd __read_mostly;
33 static bool nft_hash_rnd_initted __read_mostly;
35 static unsigned int nft_hash_data(const struct nft_data *data,
36 unsigned int hsize, unsigned int len)
40 h = jhash(data->data, len, nft_hash_rnd);
41 return ((u64)h * hsize) >> 32;
44 static bool nft_hash_lookup(const struct nft_set *set,
45 const struct nft_data *key,
46 struct nft_data *data)
48 const struct nft_hash *priv = nft_set_priv(set);
49 const struct nft_hash_elem *he;
52 h = nft_hash_data(key, priv->hsize, set->klen);
53 hlist_for_each_entry(he, &priv->hash[h], hnode) {
54 if (nft_data_cmp(&he->key, key, set->klen))
56 if (set->flags & NFT_SET_MAP)
57 nft_data_copy(data, he->data);
63 static void nft_hash_elem_destroy(const struct nft_set *set,
64 struct nft_hash_elem *he)
66 nft_data_uninit(&he->key, NFT_DATA_VALUE);
67 if (set->flags & NFT_SET_MAP)
68 nft_data_uninit(he->data, set->dtype);
72 static int nft_hash_insert(const struct nft_set *set,
73 const struct nft_set_elem *elem)
75 struct nft_hash *priv = nft_set_priv(set);
76 struct nft_hash_elem *he;
83 if (set->flags & NFT_SET_MAP)
84 size += sizeof(he->data[0]);
86 he = kzalloc(size, GFP_KERNEL);
90 nft_data_copy(&he->key, &elem->key);
91 if (set->flags & NFT_SET_MAP)
92 nft_data_copy(he->data, &elem->data);
94 h = nft_hash_data(&he->key, priv->hsize, set->klen);
95 hlist_add_head_rcu(&he->hnode, &priv->hash[h]);
99 static void nft_hash_remove(const struct nft_set *set,
100 const struct nft_set_elem *elem)
102 struct nft_hash_elem *he = elem->cookie;
104 hlist_del_rcu(&he->hnode);
108 static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
110 const struct nft_hash *priv = nft_set_priv(set);
111 struct nft_hash_elem *he;
114 h = nft_hash_data(&elem->key, priv->hsize, set->klen);
115 hlist_for_each_entry(he, &priv->hash[h], hnode) {
116 if (nft_data_cmp(&he->key, &elem->key, set->klen))
121 if (set->flags & NFT_SET_MAP)
122 nft_data_copy(&elem->data, he->data);
128 static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
129 struct nft_set_iter *iter)
131 const struct nft_hash *priv = nft_set_priv(set);
132 const struct nft_hash_elem *he;
133 struct nft_set_elem elem;
136 for (i = 0; i < priv->hsize; i++) {
137 hlist_for_each_entry(he, &priv->hash[i], hnode) {
138 if (iter->count < iter->skip)
141 memcpy(&elem.key, &he->key, sizeof(elem.key));
142 if (set->flags & NFT_SET_MAP)
143 memcpy(&elem.data, he->data, sizeof(elem.data));
146 iter->err = iter->fn(ctx, set, iter, &elem);
155 static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
157 return sizeof(struct nft_hash);
160 static int nft_hash_init(const struct nft_set *set,
161 const struct nlattr * const tb[])
163 struct nft_hash *priv = nft_set_priv(set);
166 if (unlikely(!nft_hash_rnd_initted)) {
167 get_random_bytes(&nft_hash_rnd, 4);
168 nft_hash_rnd_initted = true;
171 /* Aim for a load factor of 0.75 */
172 // FIXME: temporarily broken until we have set descriptions
176 priv->hash = kcalloc(cnt, sizeof(struct hlist_head), GFP_KERNEL);
177 if (priv->hash == NULL)
181 for (i = 0; i < cnt; i++)
182 INIT_HLIST_HEAD(&priv->hash[i]);
187 static void nft_hash_destroy(const struct nft_set *set)
189 const struct nft_hash *priv = nft_set_priv(set);
190 const struct hlist_node *next;
191 struct nft_hash_elem *elem;
194 for (i = 0; i < priv->hsize; i++) {
195 hlist_for_each_entry_safe(elem, next, &priv->hash[i], hnode) {
196 hlist_del(&elem->hnode);
197 nft_hash_elem_destroy(set, elem);
203 static struct nft_set_ops nft_hash_ops __read_mostly = {
204 .privsize = nft_hash_privsize,
205 .init = nft_hash_init,
206 .destroy = nft_hash_destroy,
208 .insert = nft_hash_insert,
209 .remove = nft_hash_remove,
210 .lookup = nft_hash_lookup,
211 .walk = nft_hash_walk,
212 .features = NFT_SET_MAP,
213 .owner = THIS_MODULE,
216 static int __init nft_hash_module_init(void)
218 return nft_register_set(&nft_hash_ops);
221 static void __exit nft_hash_module_exit(void)
223 nft_unregister_set(&nft_hash_ops);
226 module_init(nft_hash_module_init);
227 module_exit(nft_hash_module_exit);
229 MODULE_LICENSE("GPL");
230 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
231 MODULE_ALIAS_NFT_SET();