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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 const 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 struct rhash_head *he, __rcu **pprev;
87
88 pprev = elem->cookie;
89 he = rht_dereference((*pprev), priv);
90
91 rhashtable_remove_pprev(priv, he, pprev);
92
93 synchronize_rcu();
94 kfree(he);
95}
96
97static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
98{
99 const struct rhashtable *priv = nft_set_priv(set);
100 const struct bucket_table *tbl = rht_dereference_rcu(priv->tbl, priv);
101 struct rhash_head __rcu * const *pprev;
102 struct nft_hash_elem *he;
103 u32 h;
104
105 h = rhashtable_hashfn(priv, &elem->key, set->klen);
106 pprev = &tbl->buckets[h];
107 rht_for_each_entry_rcu(he, tbl->buckets[h], node) {
108 if (nft_data_cmp(&he->key, &elem->key, set->klen)) {
109 pprev = &he->node.next;
110 continue;
111 }
112
113 elem->cookie = (void *)pprev;
114 elem->flags = 0;
115 if (set->flags & NFT_SET_MAP)
116 nft_data_copy(&elem->data, he->data);
117 return 0;
118 }
119 return -ENOENT;
120}
121
122static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
123 struct nft_set_iter *iter)
124{
125 const struct rhashtable *priv = nft_set_priv(set);
126 const struct bucket_table *tbl;
127 const struct nft_hash_elem *he;
128 struct nft_set_elem elem;
129 unsigned int i;
130
131 tbl = rht_dereference_rcu(priv->tbl, priv);
132 for (i = 0; i < tbl->size; i++) {
133 rht_for_each_entry_rcu(he, tbl->buckets[i], node) {
134 if (iter->count < iter->skip)
135 goto cont;
136
137 memcpy(&elem.key, &he->key, sizeof(elem.key));
138 if (set->flags & NFT_SET_MAP)
139 memcpy(&elem.data, he->data, sizeof(elem.data));
140 elem.flags = 0;
141
142 iter->err = iter->fn(ctx, set, iter, &elem);
143 if (iter->err < 0)
144 return;
145cont:
146 iter->count++;
147 }
148 }
149}
150
151static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
152{
153 return sizeof(struct rhashtable);
154}
155
156#ifdef CONFIG_PROVE_LOCKING
157static int lockdep_nfnl_lock_is_held(void *parent)
158{
159 return lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES);
160}
161#endif
162
163static int nft_hash_init(const struct nft_set *set,
164 const struct nft_set_desc *desc,
165 const struct nlattr * const tb[])
166{
167 struct rhashtable *priv = nft_set_priv(set);
168 struct rhashtable_params params = {
169 .nelem_hint = desc->size ? : NFT_HASH_ELEMENT_HINT,
170 .head_offset = offsetof(struct nft_hash_elem, node),
171 .key_offset = offsetof(struct nft_hash_elem, key),
172 .key_len = set->klen,
173 .hashfn = jhash,
174 .grow_decision = rht_grow_above_75,
175 .shrink_decision = rht_shrink_below_30,
176#ifdef CONFIG_PROVE_LOCKING
177 .mutex_is_held = lockdep_nfnl_lock_is_held,
178#endif
179 };
180
181 return rhashtable_init(priv, ¶ms);
182}
183
184static void nft_hash_destroy(const struct nft_set *set)
185{
186 const struct rhashtable *priv = nft_set_priv(set);
187 const struct bucket_table *tbl = priv->tbl;
188 struct nft_hash_elem *he, *next;
189 unsigned int i;
190
191 for (i = 0; i < tbl->size; i++) {
192 for (he = rht_entry(tbl->buckets[i], struct nft_hash_elem, node);
193 he != NULL; he = next) {
194 next = rht_entry(he->node.next, struct nft_hash_elem, node);
195 nft_hash_elem_destroy(set, he);
196 }
197 }
198 rhashtable_destroy(priv);
199}
200
201static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
202 struct nft_set_estimate *est)
203{
204 unsigned int esize;
205
206 esize = sizeof(struct nft_hash_elem);
207 if (features & NFT_SET_MAP)
208 esize += FIELD_SIZEOF(struct nft_hash_elem, data[0]);
209
210 if (desc->size) {
211 est->size = sizeof(struct rhashtable) +
212 roundup_pow_of_two(desc->size * 4 / 3) *
213 sizeof(struct nft_hash_elem *) +
214 desc->size * esize;
215 } else {
216
217
218
219
220
221 est->size = esize + 2 * sizeof(struct nft_hash_elem *);
222 }
223
224 est->class = NFT_SET_CLASS_O_1;
225
226 return true;
227}
228
229static struct nft_set_ops nft_hash_ops __read_mostly = {
230 .privsize = nft_hash_privsize,
231 .estimate = nft_hash_estimate,
232 .init = nft_hash_init,
233 .destroy = nft_hash_destroy,
234 .get = nft_hash_get,
235 .insert = nft_hash_insert,
236 .remove = nft_hash_remove,
237 .lookup = nft_hash_lookup,
238 .walk = nft_hash_walk,
239 .features = NFT_SET_MAP,
240 .owner = THIS_MODULE,
241};
242
243static int __init nft_hash_module_init(void)
244{
245 return nft_register_set(&nft_hash_ops);
246}
247
248static void __exit nft_hash_module_exit(void)
249{
250 nft_unregister_set(&nft_hash_ops);
251}
252
253module_init(nft_hash_module_init);
254module_exit(nft_hash_module_exit);
255
256MODULE_LICENSE("GPL");
257MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
258MODULE_ALIAS_NFT_SET();
259
