xen-blkfront: don't add indirect pages to list when !feature_persistent
[linux-2.6-block.git] / net / netfilter / nft_hash.c
CommitLineData
96518518 1/*
ce6eb0d7 2 * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
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3 *
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.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/list.h>
c50b960c 15#include <linux/log2.h>
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16#include <linux/jhash.h>
17#include <linux/netlink.h>
9d098292 18#include <linux/workqueue.h>
cfe4a9dd 19#include <linux/rhashtable.h>
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20#include <linux/netfilter.h>
21#include <linux/netfilter/nf_tables.h>
22#include <net/netfilter/nf_tables.h>
23
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24/* We target a hash table size of 4, element hint is 75% of final size */
25#define NFT_HASH_ELEMENT_HINT 3
96518518 26
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27struct nft_hash {
28 struct rhashtable ht;
9d098292 29 struct delayed_work gc_work;
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30};
31
96518518 32struct nft_hash_elem {
cfe4a9dd 33 struct rhash_head node;
fe2811eb 34 struct nft_set_ext ext;
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35};
36
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37struct nft_hash_cmp_arg {
38 const struct nft_set *set;
8cd8937a 39 const u32 *key;
cc02e457 40 u8 genmask;
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41};
42
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43static const struct rhashtable_params nft_hash_params;
44
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45static inline u32 nft_hash_key(const void *data, u32 len, u32 seed)
46{
47 const struct nft_hash_cmp_arg *arg = data;
48
49 return jhash(arg->key, len, seed);
50}
51
52static inline u32 nft_hash_obj(const void *data, u32 len, u32 seed)
53{
54 const struct nft_hash_elem *he = data;
55
fe2811eb 56 return jhash(nft_set_ext_key(&he->ext), len, seed);
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57}
58
59static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
60 const void *ptr)
61{
62 const struct nft_hash_cmp_arg *x = arg->key;
63 const struct nft_hash_elem *he = ptr;
64
e562d860 65 if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
bfd6e327 66 return 1;
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67 if (nft_set_elem_expired(&he->ext))
68 return 1;
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69 if (!nft_set_elem_active(&he->ext, x->genmask))
70 return 1;
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71 return 0;
72}
73
8cd8937a 74static bool nft_hash_lookup(const struct nft_set *set, const u32 *key,
b2832dd6 75 const struct nft_set_ext **ext)
96518518 76{
745f5450 77 struct nft_hash *priv = nft_set_priv(set);
20a69341 78 const struct nft_hash_elem *he;
bfd6e327 79 struct nft_hash_cmp_arg arg = {
cc02e457 80 .genmask = nft_genmask_cur(read_pnet(&set->pnet)),
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81 .set = set,
82 .key = key,
83 };
ce6eb0d7 84
bfd6e327 85 he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
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86 if (he != NULL)
87 *ext = &he->ext;
ce6eb0d7 88
cfe4a9dd 89 return !!he;
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90}
91
8cd8937a 92static bool nft_hash_update(struct nft_set *set, const u32 *key,
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93 void *(*new)(struct nft_set *,
94 const struct nft_expr *,
a55e22e9 95 struct nft_regs *regs),
22fe54d5 96 const struct nft_expr *expr,
a55e22e9 97 struct nft_regs *regs,
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98 const struct nft_set_ext **ext)
99{
100 struct nft_hash *priv = nft_set_priv(set);
101 struct nft_hash_elem *he;
102 struct nft_hash_cmp_arg arg = {
103 .genmask = NFT_GENMASK_ANY,
104 .set = set,
105 .key = key,
106 };
107
108 he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
109 if (he != NULL)
110 goto out;
111
a55e22e9 112 he = new(set, expr, regs);
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113 if (he == NULL)
114 goto err1;
115 if (rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
116 nft_hash_params))
117 goto err2;
118out:
119 *ext = &he->ext;
120 return true;
121
122err2:
123 nft_set_elem_destroy(set, he);
124err1:
125 return false;
126}
127
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128static int nft_hash_insert(const struct nft_set *set,
129 const struct nft_set_elem *elem)
96518518 130{
745f5450 131 struct nft_hash *priv = nft_set_priv(set);
fe2811eb 132 struct nft_hash_elem *he = elem->priv;
bfd6e327 133 struct nft_hash_cmp_arg arg = {
cc02e457 134 .genmask = nft_genmask_next(read_pnet(&set->pnet)),
bfd6e327 135 .set = set,
7d740264 136 .key = elem->key.val.data,
bfd6e327 137 };
ce6eb0d7 138
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139 return rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
140 nft_hash_params);
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141}
142
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143static void nft_hash_activate(const struct nft_set *set,
144 const struct nft_set_elem *elem)
96518518 145{
cc02e457 146 struct nft_hash_elem *he = elem->priv;
ce6eb0d7 147
cc02e457 148 nft_set_elem_change_active(set, &he->ext);
9d098292 149 nft_set_elem_clear_busy(&he->ext);
20a69341 150}
96518518 151
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152static void *nft_hash_deactivate(const struct nft_set *set,
153 const struct nft_set_elem *elem)
20a69341 154{
745f5450 155 struct nft_hash *priv = nft_set_priv(set);
fa377321 156 struct nft_hash_elem *he;
bfd6e327 157 struct nft_hash_cmp_arg arg = {
cc02e457 158 .genmask = nft_genmask_next(read_pnet(&set->pnet)),
bfd6e327 159 .set = set,
7d740264 160 .key = elem->key.val.data,
bfd6e327 161 };
fa377321 162
9d098292 163 rcu_read_lock();
bfd6e327 164 he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
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165 if (he != NULL) {
166 if (!nft_set_elem_mark_busy(&he->ext))
167 nft_set_elem_change_active(set, &he->ext);
168 else
169 he = NULL;
170 }
171 rcu_read_unlock();
8d24c0b4 172
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173 return he;
174}
8d24c0b4 175
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176static void nft_hash_remove(const struct nft_set *set,
177 const struct nft_set_elem *elem)
178{
179 struct nft_hash *priv = nft_set_priv(set);
180 struct nft_hash_elem *he = elem->priv;
181
182 rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
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183}
184
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185static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
186 struct nft_set_iter *iter)
96518518 187{
745f5450 188 struct nft_hash *priv = nft_set_priv(set);
fe2811eb 189 struct nft_hash_elem *he;
9a776628 190 struct rhashtable_iter hti;
20a69341 191 struct nft_set_elem elem;
cc02e457 192 u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
9a776628 193 int err;
96518518 194
745f5450 195 err = rhashtable_walk_init(&priv->ht, &hti);
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196 iter->err = err;
197 if (err)
198 return;
88d6ed15 199
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200 err = rhashtable_walk_start(&hti);
201 if (err && err != -EAGAIN) {
202 iter->err = err;
203 goto out;
204 }
205
206 while ((he = rhashtable_walk_next(&hti))) {
207 if (IS_ERR(he)) {
208 err = PTR_ERR(he);
209 if (err != -EAGAIN) {
210 iter->err = err;
211 goto out;
212 }
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213
214 continue;
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215 }
216
217 if (iter->count < iter->skip)
218 goto cont;
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219 if (nft_set_elem_expired(&he->ext))
220 goto cont;
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221 if (!nft_set_elem_active(&he->ext, genmask))
222 goto cont;
20a69341 223
fe2811eb 224 elem.priv = he;
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225
226 iter->err = iter->fn(ctx, set, iter, &elem);
227 if (iter->err < 0)
228 goto out;
20a69341 229
20a69341 230cont:
9a776628 231 iter->count++;
96518518 232 }
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233
234out:
235 rhashtable_walk_stop(&hti);
236 rhashtable_walk_exit(&hti);
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237}
238
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239static void nft_hash_gc(struct work_struct *work)
240{
3dd0673a 241 struct nft_set *set;
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242 struct nft_hash_elem *he;
243 struct nft_hash *priv;
244 struct nft_set_gc_batch *gcb = NULL;
245 struct rhashtable_iter hti;
246 int err;
247
248 priv = container_of(work, struct nft_hash, gc_work.work);
249 set = nft_set_container_of(priv);
250
251 err = rhashtable_walk_init(&priv->ht, &hti);
252 if (err)
253 goto schedule;
254
255 err = rhashtable_walk_start(&hti);
256 if (err && err != -EAGAIN)
257 goto out;
258
259 while ((he = rhashtable_walk_next(&hti))) {
260 if (IS_ERR(he)) {
261 if (PTR_ERR(he) != -EAGAIN)
262 goto out;
263 continue;
264 }
265
266 if (!nft_set_elem_expired(&he->ext))
267 continue;
268 if (nft_set_elem_mark_busy(&he->ext))
269 continue;
270
271 gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
272 if (gcb == NULL)
273 goto out;
274 rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
3dd0673a 275 atomic_dec(&set->nelems);
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276 nft_set_gc_batch_add(gcb, he);
277 }
278out:
279 rhashtable_walk_stop(&hti);
280 rhashtable_walk_exit(&hti);
281
282 nft_set_gc_batch_complete(gcb);
283schedule:
284 queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
285 nft_set_gc_interval(set));
286}
287
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288static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
289{
745f5450 290 return sizeof(struct nft_hash);
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291}
292
fa377321 293static const struct rhashtable_params nft_hash_params = {
45d84751 294 .head_offset = offsetof(struct nft_hash_elem, node),
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295 .hashfn = nft_hash_key,
296 .obj_hashfn = nft_hash_obj,
297 .obj_cmpfn = nft_hash_cmp,
45d84751 298 .automatic_shrinking = true,
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299};
300
20a69341 301static int nft_hash_init(const struct nft_set *set,
c50b960c 302 const struct nft_set_desc *desc,
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303 const struct nlattr * const tb[])
304{
745f5450 305 struct nft_hash *priv = nft_set_priv(set);
fa377321 306 struct rhashtable_params params = nft_hash_params;
9d098292 307 int err;
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308
309 params.nelem_hint = desc->size ?: NFT_HASH_ELEMENT_HINT;
45d84751 310 params.key_len = set->klen;
96518518 311
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312 err = rhashtable_init(&priv->ht, &params);
313 if (err < 0)
314 return err;
315
316 INIT_DEFERRABLE_WORK(&priv->gc_work, nft_hash_gc);
317 if (set->flags & NFT_SET_TIMEOUT)
318 queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
319 nft_set_gc_interval(set));
320 return 0;
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321}
322
61edafbb 323static void nft_hash_elem_destroy(void *ptr, void *arg)
96518518 324{
61edafbb 325 nft_set_elem_destroy((const struct nft_set *)arg, ptr);
6b6f302c 326}
97defe1e 327
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328static void nft_hash_destroy(const struct nft_set *set)
329{
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330 struct nft_hash *priv = nft_set_priv(set);
331
9d098292 332 cancel_delayed_work_sync(&priv->gc_work);
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333 rhashtable_free_and_destroy(&priv->ht, nft_hash_elem_destroy,
334 (void *)set);
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335}
336
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337static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
338 struct nft_set_estimate *est)
339{
340 unsigned int esize;
341
342 esize = sizeof(struct nft_hash_elem);
c50b960c 343 if (desc->size) {
745f5450 344 est->size = sizeof(struct nft_hash) +
cfe4a9dd 345 roundup_pow_of_two(desc->size * 4 / 3) *
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346 sizeof(struct nft_hash_elem *) +
347 desc->size * esize;
348 } else {
349 /* Resizing happens when the load drops below 30% or goes
350 * above 75%. The average of 52.5% load (approximated by 50%)
351 * is used for the size estimation of the hash buckets,
352 * meaning we calculate two buckets per element.
353 */
354 est->size = esize + 2 * sizeof(struct nft_hash_elem *);
355 }
356
357 est->class = NFT_SET_CLASS_O_1;
358
359 return true;
360}
361
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362static struct nft_set_ops nft_hash_ops __read_mostly = {
363 .privsize = nft_hash_privsize,
fe2811eb 364 .elemsize = offsetof(struct nft_hash_elem, ext),
c50b960c 365 .estimate = nft_hash_estimate,
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366 .init = nft_hash_init,
367 .destroy = nft_hash_destroy,
20a69341 368 .insert = nft_hash_insert,
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369 .activate = nft_hash_activate,
370 .deactivate = nft_hash_deactivate,
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371 .remove = nft_hash_remove,
372 .lookup = nft_hash_lookup,
22fe54d5 373 .update = nft_hash_update,
20a69341 374 .walk = nft_hash_walk,
9d098292 375 .features = NFT_SET_MAP | NFT_SET_TIMEOUT,
20a69341 376 .owner = THIS_MODULE,
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377};
378
379static int __init nft_hash_module_init(void)
380{
20a69341 381 return nft_register_set(&nft_hash_ops);
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382}
383
384static void __exit nft_hash_module_exit(void)
385{
20a69341 386 nft_unregister_set(&nft_hash_ops);
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387}
388
389module_init(nft_hash_module_init);
390module_exit(nft_hash_module_exit);
391
392MODULE_LICENSE("GPL");
393MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
20a69341 394MODULE_ALIAS_NFT_SET();