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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/log2.h>
16#include <linux/jhash.h>
17#include <linux/netlink.h>
18#include <linux/rhashtable.h>
19#include <linux/netfilter.h>
20#include <linux/netfilter/nf_tables.h>
21#include <net/netfilter/nf_tables.h>
22
23
24#define NFT_HASH_ELEMENT_HINT 3
25
26struct nft_hash_elem {
27 struct rhash_head node;
28 struct nft_data key;
29 struct nft_data data[];
30};
31
32static bool nft_hash_lookup(const struct nft_set *set,
33 const struct nft_data *key,
34 struct nft_data *data)
35{
36 struct rhashtable *priv = nft_set_priv(set);
37 const struct nft_hash_elem *he;
38
39 he = rhashtable_lookup(priv, key);
40 if (he && set->flags & NFT_SET_MAP)
41 nft_data_copy(data, he->data);
42
43 return !!he;
44}
45
46static int nft_hash_insert(const struct nft_set *set,
47 const struct nft_set_elem *elem)
48{
49 struct rhashtable *priv = nft_set_priv(set);
50 struct nft_hash_elem *he;
51 unsigned int size;
52
53 if (elem->flags != 0)
54 return -EINVAL;
55
56 size = sizeof(*he);
57 if (set->flags & NFT_SET_MAP)
58 size += sizeof(he->data[0]);
59
60 he = kzalloc(size, GFP_KERNEL);
61 if (he == NULL)
62 return -ENOMEM;
63
64 nft_data_copy(&he->key, &elem->key);
65 if (set->flags & NFT_SET_MAP)
66 nft_data_copy(he->data, &elem->data);
67
68 rhashtable_insert(priv, &he->node);
69
70 return 0;
71}
72
73static void nft_hash_elem_destroy(const struct nft_set *set,
74 struct nft_hash_elem *he)
75{
76 nft_data_uninit(&he->key, NFT_DATA_VALUE);
77 if (set->flags & NFT_SET_MAP)
78 nft_data_uninit(he->data, set->dtype);
79 kfree(he);
80}
81
82static void nft_hash_remove(const struct nft_set *set,
83 const struct nft_set_elem *elem)
84{
85 struct rhashtable *priv = nft_set_priv(set);
86
87 rhashtable_remove(priv, elem->cookie);
88 synchronize_rcu();
89 kfree(elem->cookie);
90}
91
92struct nft_compare_arg {
93 const struct nft_set *set;
94 struct nft_set_elem *elem;
95};
96
97static bool nft_hash_compare(void *ptr, void *arg)
98{
99 struct nft_hash_elem *he = ptr;
100 struct nft_compare_arg *x = arg;
101
102 if (!nft_data_cmp(&he->key, &x->elem->key, x->set->klen)) {
103 x->elem->cookie = he;
104 x->elem->flags = 0;
105 if (x->set->flags & NFT_SET_MAP)
106 nft_data_copy(&x->elem->data, he->data);
107
108 return true;
109 }
110
111 return false;
112}
113
114static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
115{
116 struct rhashtable *priv = nft_set_priv(set);
117 struct nft_compare_arg arg = {
118 .set = set,
119 .elem = elem,
120 };
121
122 if (rhashtable_lookup_compare(priv, &elem->key,
123 &nft_hash_compare, &arg))
124 return 0;
125
126 return -ENOENT;
127}
128
129static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
130 struct nft_set_iter *iter)
131{
132 struct rhashtable *priv = nft_set_priv(set);
133 const struct nft_hash_elem *he;
134 struct rhashtable_iter hti;
135 struct nft_set_elem elem;
136 int err;
137
138 err = rhashtable_walk_init(priv, &hti);
139 iter->err = err;
140 if (err)
141 return;
142
143 err = rhashtable_walk_start(&hti);
144 if (err && err != -EAGAIN) {
145 iter->err = err;
146 goto out;
147 }
148
149 while ((he = rhashtable_walk_next(&hti))) {
150 if (IS_ERR(he)) {
151 err = PTR_ERR(he);
152 if (err != -EAGAIN) {
153 iter->err = err;
154 goto out;
155 }
156
157 continue;
158 }
159
160 if (iter->count < iter->skip)
161 goto cont;
162
163 memcpy(&elem.key, &he->key, sizeof(elem.key));
164 if (set->flags & NFT_SET_MAP)
165 memcpy(&elem.data, he->data, sizeof(elem.data));
166 elem.flags = 0;
167
168 iter->err = iter->fn(ctx, set, iter, &elem);
169 if (iter->err < 0)
170 goto out;
171
172cont:
173 iter->count++;
174 }
175
176out:
177 rhashtable_walk_stop(&hti);
178 rhashtable_walk_exit(&hti);
179}
180
181static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
182{
183 return sizeof(struct rhashtable);
184}
185
186static int nft_hash_init(const struct nft_set *set,
187 const struct nft_set_desc *desc,
188 const struct nlattr * const tb[])
189{
190 struct rhashtable *priv = nft_set_priv(set);
191 struct rhashtable_params params = {
192 .nelem_hint = desc->size ? : NFT_HASH_ELEMENT_HINT,
193 .head_offset = offsetof(struct nft_hash_elem, node),
194 .key_offset = offsetof(struct nft_hash_elem, key),
195 .key_len = set->klen,
196 .hashfn = jhash,
197 };
198
199 return rhashtable_init(priv, ¶ms);
200}
201
202static void nft_hash_destroy(const struct nft_set *set)
203{
204 struct rhashtable *priv = nft_set_priv(set);
205 const struct bucket_table *tbl;
206 struct nft_hash_elem *he;
207 struct rhash_head *pos, *next;
208 unsigned int i;
209
210
211 priv->being_destroyed = true;
212 mutex_lock(&priv->mutex);
213
214 tbl = rht_dereference(priv->tbl, priv);
215 for (i = 0; i < tbl->size; i++) {
216 rht_for_each_entry_safe(he, pos, next, tbl, i, node)
217 nft_hash_elem_destroy(set, he);
218 }
219 mutex_unlock(&priv->mutex);
220
221 rhashtable_destroy(priv);
222}
223
224static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
225 struct nft_set_estimate *est)
226{
227 unsigned int esize;
228
229 esize = sizeof(struct nft_hash_elem);
230 if (features & NFT_SET_MAP)
231 esize += FIELD_SIZEOF(struct nft_hash_elem, data[0]);
232
233 if (desc->size) {
234 est->size = sizeof(struct rhashtable) +
235 roundup_pow_of_two(desc->size * 4 / 3) *
236 sizeof(struct nft_hash_elem *) +
237 desc->size * esize;
238 } else {
239
240
241
242
243
244 est->size = esize + 2 * sizeof(struct nft_hash_elem *);
245 }
246
247 est->class = NFT_SET_CLASS_O_1;
248
249 return true;
250}
251
252static struct nft_set_ops nft_hash_ops __read_mostly = {
253 .privsize = nft_hash_privsize,
254 .estimate = nft_hash_estimate,
255 .init = nft_hash_init,
256 .destroy = nft_hash_destroy,
257 .get = nft_hash_get,
258 .insert = nft_hash_insert,
259 .remove = nft_hash_remove,
260 .lookup = nft_hash_lookup,
261 .walk = nft_hash_walk,
262 .features = NFT_SET_MAP,
263 .owner = THIS_MODULE,
264};
265
266static int __init nft_hash_module_init(void)
267{
268 return nft_register_set(&nft_hash_ops);
269}
270
271static void __exit nft_hash_module_exit(void)
272{
273 nft_unregister_set(&nft_hash_ops);
274}
275
276module_init(nft_hash_module_init);
277module_exit(nft_hash_module_exit);
278
279MODULE_LICENSE("GPL");
280MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
281MODULE_ALIAS_NFT_SET();
282
