Merge remote-tracking branch 'omap_dss2/for-next'
[deliverable/linux.git] / net / netfilter / nft_set_hash.c
1 /*
2 * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
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>
15 #include <linux/log2.h>
16 #include <linux/jhash.h>
17 #include <linux/netlink.h>
18 #include <linux/workqueue.h>
19 #include <linux/rhashtable.h>
20 #include <linux/netfilter.h>
21 #include <linux/netfilter/nf_tables.h>
22 #include <net/netfilter/nf_tables.h>
23
24 /* We target a hash table size of 4, element hint is 75% of final size */
25 #define NFT_HASH_ELEMENT_HINT 3
26
27 struct nft_hash {
28 struct rhashtable ht;
29 struct delayed_work gc_work;
30 };
31
32 struct nft_hash_elem {
33 struct rhash_head node;
34 struct nft_set_ext ext;
35 };
36
37 struct nft_hash_cmp_arg {
38 const struct nft_set *set;
39 const u32 *key;
40 u8 genmask;
41 };
42
43 static const struct rhashtable_params nft_hash_params;
44
45 static 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
52 static inline u32 nft_hash_obj(const void *data, u32 len, u32 seed)
53 {
54 const struct nft_hash_elem *he = data;
55
56 return jhash(nft_set_ext_key(&he->ext), len, seed);
57 }
58
59 static 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
65 if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
66 return 1;
67 if (nft_set_elem_expired(&he->ext))
68 return 1;
69 if (!nft_set_elem_active(&he->ext, x->genmask))
70 return 1;
71 return 0;
72 }
73
74 static bool nft_hash_lookup(const struct net *net, const struct nft_set *set,
75 const u32 *key, const struct nft_set_ext **ext)
76 {
77 struct nft_hash *priv = nft_set_priv(set);
78 const struct nft_hash_elem *he;
79 struct nft_hash_cmp_arg arg = {
80 .genmask = nft_genmask_cur(net),
81 .set = set,
82 .key = key,
83 };
84
85 he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
86 if (he != NULL)
87 *ext = &he->ext;
88
89 return !!he;
90 }
91
92 static bool nft_hash_update(struct nft_set *set, const u32 *key,
93 void *(*new)(struct nft_set *,
94 const struct nft_expr *,
95 struct nft_regs *regs),
96 const struct nft_expr *expr,
97 struct nft_regs *regs,
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
112 he = new(set, expr, regs);
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;
118 out:
119 *ext = &he->ext;
120 return true;
121
122 err2:
123 nft_set_elem_destroy(set, he);
124 err1:
125 return false;
126 }
127
128 static int nft_hash_insert(const struct net *net, const struct nft_set *set,
129 const struct nft_set_elem *elem,
130 struct nft_set_ext **ext)
131 {
132 struct nft_hash *priv = nft_set_priv(set);
133 struct nft_hash_elem *he = elem->priv;
134 struct nft_hash_cmp_arg arg = {
135 .genmask = nft_genmask_next(net),
136 .set = set,
137 .key = elem->key.val.data,
138 };
139 struct nft_hash_elem *prev;
140
141 prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
142 nft_hash_params);
143 if (IS_ERR(prev))
144 return PTR_ERR(prev);
145 if (prev) {
146 *ext = &prev->ext;
147 return -EEXIST;
148 }
149 return 0;
150 }
151
152 static void nft_hash_activate(const struct net *net, const struct nft_set *set,
153 const struct nft_set_elem *elem)
154 {
155 struct nft_hash_elem *he = elem->priv;
156
157 nft_set_elem_change_active(net, set, &he->ext);
158 nft_set_elem_clear_busy(&he->ext);
159 }
160
161 static void *nft_hash_deactivate(const struct net *net,
162 const struct nft_set *set,
163 const struct nft_set_elem *elem)
164 {
165 struct nft_hash *priv = nft_set_priv(set);
166 struct nft_hash_elem *he;
167 struct nft_hash_cmp_arg arg = {
168 .genmask = nft_genmask_next(net),
169 .set = set,
170 .key = elem->key.val.data,
171 };
172
173 rcu_read_lock();
174 he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
175 if (he != NULL) {
176 if (!nft_set_elem_mark_busy(&he->ext) ||
177 !nft_is_active(net, &he->ext))
178 nft_set_elem_change_active(net, set, &he->ext);
179 else
180 he = NULL;
181 }
182 rcu_read_unlock();
183
184 return he;
185 }
186
187 static void nft_hash_remove(const struct nft_set *set,
188 const struct nft_set_elem *elem)
189 {
190 struct nft_hash *priv = nft_set_priv(set);
191 struct nft_hash_elem *he = elem->priv;
192
193 rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
194 }
195
196 static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
197 struct nft_set_iter *iter)
198 {
199 struct nft_hash *priv = nft_set_priv(set);
200 struct nft_hash_elem *he;
201 struct rhashtable_iter hti;
202 struct nft_set_elem elem;
203 int err;
204
205 err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
206 iter->err = err;
207 if (err)
208 return;
209
210 err = rhashtable_walk_start(&hti);
211 if (err && err != -EAGAIN) {
212 iter->err = err;
213 goto out;
214 }
215
216 while ((he = rhashtable_walk_next(&hti))) {
217 if (IS_ERR(he)) {
218 err = PTR_ERR(he);
219 if (err != -EAGAIN) {
220 iter->err = err;
221 goto out;
222 }
223
224 continue;
225 }
226
227 if (iter->count < iter->skip)
228 goto cont;
229 if (nft_set_elem_expired(&he->ext))
230 goto cont;
231 if (!nft_set_elem_active(&he->ext, iter->genmask))
232 goto cont;
233
234 elem.priv = he;
235
236 iter->err = iter->fn(ctx, set, iter, &elem);
237 if (iter->err < 0)
238 goto out;
239
240 cont:
241 iter->count++;
242 }
243
244 out:
245 rhashtable_walk_stop(&hti);
246 rhashtable_walk_exit(&hti);
247 }
248
249 static void nft_hash_gc(struct work_struct *work)
250 {
251 struct nft_set *set;
252 struct nft_hash_elem *he;
253 struct nft_hash *priv;
254 struct nft_set_gc_batch *gcb = NULL;
255 struct rhashtable_iter hti;
256 int err;
257
258 priv = container_of(work, struct nft_hash, gc_work.work);
259 set = nft_set_container_of(priv);
260
261 err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL);
262 if (err)
263 goto schedule;
264
265 err = rhashtable_walk_start(&hti);
266 if (err && err != -EAGAIN)
267 goto out;
268
269 while ((he = rhashtable_walk_next(&hti))) {
270 if (IS_ERR(he)) {
271 if (PTR_ERR(he) != -EAGAIN)
272 goto out;
273 continue;
274 }
275
276 if (!nft_set_elem_expired(&he->ext))
277 continue;
278 if (nft_set_elem_mark_busy(&he->ext))
279 continue;
280
281 gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
282 if (gcb == NULL)
283 goto out;
284 rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
285 atomic_dec(&set->nelems);
286 nft_set_gc_batch_add(gcb, he);
287 }
288 out:
289 rhashtable_walk_stop(&hti);
290 rhashtable_walk_exit(&hti);
291
292 nft_set_gc_batch_complete(gcb);
293 schedule:
294 queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
295 nft_set_gc_interval(set));
296 }
297
298 static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
299 {
300 return sizeof(struct nft_hash);
301 }
302
303 static const struct rhashtable_params nft_hash_params = {
304 .head_offset = offsetof(struct nft_hash_elem, node),
305 .hashfn = nft_hash_key,
306 .obj_hashfn = nft_hash_obj,
307 .obj_cmpfn = nft_hash_cmp,
308 .automatic_shrinking = true,
309 };
310
311 static int nft_hash_init(const struct nft_set *set,
312 const struct nft_set_desc *desc,
313 const struct nlattr * const tb[])
314 {
315 struct nft_hash *priv = nft_set_priv(set);
316 struct rhashtable_params params = nft_hash_params;
317 int err;
318
319 params.nelem_hint = desc->size ?: NFT_HASH_ELEMENT_HINT;
320 params.key_len = set->klen;
321
322 err = rhashtable_init(&priv->ht, &params);
323 if (err < 0)
324 return err;
325
326 INIT_DEFERRABLE_WORK(&priv->gc_work, nft_hash_gc);
327 if (set->flags & NFT_SET_TIMEOUT)
328 queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
329 nft_set_gc_interval(set));
330 return 0;
331 }
332
333 static void nft_hash_elem_destroy(void *ptr, void *arg)
334 {
335 nft_set_elem_destroy((const struct nft_set *)arg, ptr);
336 }
337
338 static void nft_hash_destroy(const struct nft_set *set)
339 {
340 struct nft_hash *priv = nft_set_priv(set);
341
342 cancel_delayed_work_sync(&priv->gc_work);
343 rhashtable_free_and_destroy(&priv->ht, nft_hash_elem_destroy,
344 (void *)set);
345 }
346
347 static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
348 struct nft_set_estimate *est)
349 {
350 unsigned int esize;
351
352 esize = sizeof(struct nft_hash_elem);
353 if (desc->size) {
354 est->size = sizeof(struct nft_hash) +
355 roundup_pow_of_two(desc->size * 4 / 3) *
356 sizeof(struct nft_hash_elem *) +
357 desc->size * esize;
358 } else {
359 /* Resizing happens when the load drops below 30% or goes
360 * above 75%. The average of 52.5% load (approximated by 50%)
361 * is used for the size estimation of the hash buckets,
362 * meaning we calculate two buckets per element.
363 */
364 est->size = esize + 2 * sizeof(struct nft_hash_elem *);
365 }
366
367 est->class = NFT_SET_CLASS_O_1;
368
369 return true;
370 }
371
372 static struct nft_set_ops nft_hash_ops __read_mostly = {
373 .privsize = nft_hash_privsize,
374 .elemsize = offsetof(struct nft_hash_elem, ext),
375 .estimate = nft_hash_estimate,
376 .init = nft_hash_init,
377 .destroy = nft_hash_destroy,
378 .insert = nft_hash_insert,
379 .activate = nft_hash_activate,
380 .deactivate = nft_hash_deactivate,
381 .remove = nft_hash_remove,
382 .lookup = nft_hash_lookup,
383 .update = nft_hash_update,
384 .walk = nft_hash_walk,
385 .features = NFT_SET_MAP | NFT_SET_TIMEOUT,
386 .owner = THIS_MODULE,
387 };
388
389 static int __init nft_hash_module_init(void)
390 {
391 return nft_register_set(&nft_hash_ops);
392 }
393
394 static void __exit nft_hash_module_exit(void)
395 {
396 nft_unregister_set(&nft_hash_ops);
397 }
398
399 module_init(nft_hash_module_init);
400 module_exit(nft_hash_module_exit);
401
402 MODULE_LICENSE("GPL");
403 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
404 MODULE_ALIAS_NFT_SET();
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