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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>
20
21struct nft_hash {
22 struct hlist_head *hash;
23 unsigned int hsize;
24};
25
26struct nft_hash_elem {
27 struct hlist_node hnode;
28 struct nft_data key;
29 struct nft_data data[];
30};
31
32static u32 nft_hash_rnd __read_mostly;
33static bool nft_hash_rnd_initted __read_mostly;
34
35static unsigned int nft_hash_data(const struct nft_data *data,
36 unsigned int hsize, unsigned int len)
37{
38 unsigned int h;
39
40 h = jhash(data->data, len, nft_hash_rnd);
41 return ((u64)h * hsize) >> 32;
42}
43
44static bool nft_hash_lookup(const struct nft_set *set,
45 const struct nft_data *key,
46 struct nft_data *data)
47{
48 const struct nft_hash *priv = nft_set_priv(set);
49 const struct nft_hash_elem *he;
50 unsigned int h;
51
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))
55 continue;
56 if (set->flags & NFT_SET_MAP)
57 nft_data_copy(data, he->data);
58 return true;
59 }
60 return false;
61}
62
63static void nft_hash_elem_destroy(const struct nft_set *set,
64 struct nft_hash_elem *he)
65{
66 nft_data_uninit(&he->key, NFT_DATA_VALUE);
67 if (set->flags & NFT_SET_MAP)
68 nft_data_uninit(he->data, set->dtype);
69 kfree(he);
70}
71
72static int nft_hash_insert(const struct nft_set *set,
73 const struct nft_set_elem *elem)
74{
75 struct nft_hash *priv = nft_set_priv(set);
76 struct nft_hash_elem *he;
77 unsigned int size, h;
78
79 if (elem->flags != 0)
80 return -EINVAL;
81
82 size = sizeof(*he);
83 if (set->flags & NFT_SET_MAP)
84 size += sizeof(he->data[0]);
85
86 he = kzalloc(size, GFP_KERNEL);
87 if (he == NULL)
88 return -ENOMEM;
89
90 nft_data_copy(&he->key, &elem->key);
91 if (set->flags & NFT_SET_MAP)
92 nft_data_copy(he->data, &elem->data);
93
94 h = nft_hash_data(&he->key, priv->hsize, set->klen);
95 hlist_add_head_rcu(&he->hnode, &priv->hash[h]);
96 return 0;
97}
98
99static void nft_hash_remove(const struct nft_set *set,
100 const struct nft_set_elem *elem)
101{
102 struct nft_hash_elem *he = elem->cookie;
103
104 hlist_del_rcu(&he->hnode);
105 kfree(he);
106}
107
108static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
109{
110 const struct nft_hash *priv = nft_set_priv(set);
111 struct nft_hash_elem *he;
112 unsigned int h;
113
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))
117 continue;
118
119 elem->cookie = he;
120 elem->flags = 0;
121 if (set->flags & NFT_SET_MAP)
122 nft_data_copy(&elem->data, he->data);
123 return 0;
124 }
125 return -ENOENT;
126}
127
128static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
129 struct nft_set_iter *iter)
130{
131 const struct nft_hash *priv = nft_set_priv(set);
132 const struct nft_hash_elem *he;
133 struct nft_set_elem elem;
134 unsigned int i;
135
136 for (i = 0; i < priv->hsize; i++) {
137 hlist_for_each_entry(he, &priv->hash[i], hnode) {
138 if (iter->count < iter->skip)
139 goto cont;
140
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));
144 elem.flags = 0;
145
146 iter->err = iter->fn(ctx, set, iter, &elem);
147 if (iter->err < 0)
148 return;
149cont:
150 iter->count++;
151 }
152 }
153}
154
155static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
156{
157 return sizeof(struct nft_hash);
158}
159
160static int nft_hash_init(const struct nft_set *set,
161 const struct nlattr * const tb[])
162{
163 struct nft_hash *priv = nft_set_priv(set);
164 unsigned int cnt, i;
165
166 if (unlikely(!nft_hash_rnd_initted)) {
167 get_random_bytes(&nft_hash_rnd, 4);
168 nft_hash_rnd_initted = true;
169 }
170
171
172
173 cnt = 100;
174 cnt = cnt * 4 / 3;
175
176 priv->hash = kcalloc(cnt, sizeof(struct hlist_head), GFP_KERNEL);
177 if (priv->hash == NULL)
178 return -ENOMEM;
179 priv->hsize = cnt;
180
181 for (i = 0; i < cnt; i++)
182 INIT_HLIST_HEAD(&priv->hash[i]);
183
184 return 0;
185}
186
187static void nft_hash_destroy(const struct nft_set *set)
188{
189 const struct nft_hash *priv = nft_set_priv(set);
190 const struct hlist_node *next;
191 struct nft_hash_elem *elem;
192 unsigned int i;
193
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);
198 }
199 }
200 kfree(priv->hash);
201}
202
203static struct nft_set_ops nft_hash_ops __read_mostly = {
204 .privsize = nft_hash_privsize,
205 .init = nft_hash_init,
206 .destroy = nft_hash_destroy,
207 .get = nft_hash_get,
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,
214};
215
216static int __init nft_hash_module_init(void)
217{
218 return nft_register_set(&nft_hash_ops);
219}
220
221static void __exit nft_hash_module_exit(void)
222{
223 nft_unregister_set(&nft_hash_ops);
224}
225
226module_init(nft_hash_module_init);
227module_exit(nft_hash_module_exit);
228
229MODULE_LICENSE("GPL");
230MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
231MODULE_ALIAS_NFT_SET();
232
