xref: /linux/net/netfilter/nft_set_hash.c (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
4  *
5  * Development of this code funded by Astaro AG (http://www.astaro.com/)
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/list.h>
12 #include <linux/log2.h>
13 #include <linux/jhash.h>
14 #include <linux/netlink.h>
15 #include <linux/workqueue.h>
16 #include <linux/rhashtable.h>
17 #include <linux/netfilter.h>
18 #include <linux/netfilter/nf_tables.h>
19 #include <net/netfilter/nf_tables_core.h>
20 
21 /* We target a hash table size of 4, element hint is 75% of final size */
22 #define NFT_RHASH_ELEMENT_HINT 3
23 
24 struct nft_rhash {
25 	struct rhashtable		ht;
26 	struct delayed_work		gc_work;
27 	u32				wq_gc_seq;
28 };
29 
30 struct nft_rhash_elem {
31 	struct nft_elem_priv		priv;
32 	struct rhash_head		node;
33 	u32				wq_gc_seq;
34 	struct nft_set_ext		ext;
35 };
36 
37 struct nft_rhash_cmp_arg {
38 	const struct nft_set		*set;
39 	const u32			*key;
40 	u8				genmask;
41 	u64				tstamp;
42 };
43 
nft_rhash_key(const void * data,u32 len,u32 seed)44 static inline u32 nft_rhash_key(const void *data, u32 len, u32 seed)
45 {
46 	const struct nft_rhash_cmp_arg *arg = data;
47 
48 	return jhash(arg->key, len, seed);
49 }
50 
nft_rhash_obj(const void * data,u32 len,u32 seed)51 static inline u32 nft_rhash_obj(const void *data, u32 len, u32 seed)
52 {
53 	const struct nft_rhash_elem *he = data;
54 
55 	return jhash(nft_set_ext_key(&he->ext), len, seed);
56 }
57 
nft_rhash_cmp(struct rhashtable_compare_arg * arg,const void * ptr)58 static inline int nft_rhash_cmp(struct rhashtable_compare_arg *arg,
59 				const void *ptr)
60 {
61 	const struct nft_rhash_cmp_arg *x = arg->key;
62 	const struct nft_rhash_elem *he = ptr;
63 
64 	if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
65 		return 1;
66 	if (nft_set_elem_is_dead(&he->ext))
67 		return 1;
68 	if (__nft_set_elem_expired(&he->ext, x->tstamp))
69 		return 1;
70 	if (!nft_set_elem_active(&he->ext, x->genmask))
71 		return 1;
72 	return 0;
73 }
74 
75 static const struct rhashtable_params nft_rhash_params = {
76 	.head_offset		= offsetof(struct nft_rhash_elem, node),
77 	.hashfn			= nft_rhash_key,
78 	.obj_hashfn		= nft_rhash_obj,
79 	.obj_cmpfn		= nft_rhash_cmp,
80 	.automatic_shrinking	= true,
81 };
82 
83 INDIRECT_CALLABLE_SCOPE
84 const struct nft_set_ext *
nft_rhash_lookup(const struct net * net,const struct nft_set * set,const u32 * key)85 nft_rhash_lookup(const struct net *net, const struct nft_set *set,
86 		 const u32 *key)
87 {
88 	struct nft_rhash *priv = nft_set_priv(set);
89 	const struct nft_rhash_elem *he;
90 	struct nft_rhash_cmp_arg arg = {
91 		.genmask = nft_genmask_cur(net),
92 		.set	 = set,
93 		.key	 = key,
94 		.tstamp  = get_jiffies_64(),
95 	};
96 
97 	he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
98 	if (he != NULL)
99 		return &he->ext;
100 
101 	return NULL;
102 }
103 
104 static struct nft_elem_priv *
nft_rhash_get(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem,unsigned int flags)105 nft_rhash_get(const struct net *net, const struct nft_set *set,
106 	      const struct nft_set_elem *elem, unsigned int flags)
107 {
108 	struct nft_rhash *priv = nft_set_priv(set);
109 	struct nft_rhash_elem *he;
110 	struct nft_rhash_cmp_arg arg = {
111 		.genmask = nft_genmask_cur(net),
112 		.set	 = set,
113 		.key	 = elem->key.val.data,
114 		.tstamp  = get_jiffies_64(),
115 	};
116 
117 	he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
118 	if (he != NULL)
119 		return &he->priv;
120 
121 	return ERR_PTR(-ENOENT);
122 }
123 
124 static const struct nft_set_ext *
nft_rhash_update(struct nft_set * set,const u32 * key,const struct nft_expr * expr,struct nft_regs * regs)125 nft_rhash_update(struct nft_set *set, const u32 *key,
126 		 const struct nft_expr *expr, struct nft_regs *regs)
127 {
128 	struct nft_rhash *priv = nft_set_priv(set);
129 	struct nft_rhash_elem *he, *prev;
130 	struct nft_elem_priv *elem_priv;
131 	struct nft_rhash_cmp_arg arg = {
132 		.genmask = NFT_GENMASK_ANY,
133 		.set	 = set,
134 		.key	 = key,
135 		.tstamp  = get_jiffies_64(),
136 	};
137 
138 	he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
139 	if (he != NULL)
140 		goto out;
141 
142 	elem_priv = nft_dynset_new(set, expr, regs);
143 	if (!elem_priv)
144 		goto err1;
145 
146 	he = nft_elem_priv_cast(elem_priv);
147 	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
148 						nft_rhash_params);
149 	if (IS_ERR(prev))
150 		goto err2;
151 
152 	/* Another cpu may race to insert the element with the same key */
153 	if (prev) {
154 		nft_set_elem_destroy(set, &he->priv, true);
155 		atomic_dec(&set->nelems);
156 		he = prev;
157 	}
158 
159 out:
160 	return &he->ext;
161 
162 err2:
163 	nft_set_elem_destroy(set, &he->priv, true);
164 	atomic_dec(&set->nelems);
165 err1:
166 	return NULL;
167 }
168 
nft_rhash_insert(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem,struct nft_elem_priv ** elem_priv)169 static int nft_rhash_insert(const struct net *net, const struct nft_set *set,
170 			    const struct nft_set_elem *elem,
171 			    struct nft_elem_priv **elem_priv)
172 {
173 	struct nft_rhash_elem *he = nft_elem_priv_cast(elem->priv);
174 	struct nft_rhash *priv = nft_set_priv(set);
175 	struct nft_rhash_cmp_arg arg = {
176 		.genmask = nft_genmask_next(net),
177 		.set	 = set,
178 		.key	 = elem->key.val.data,
179 		.tstamp	 = nft_net_tstamp(net),
180 	};
181 	struct nft_rhash_elem *prev;
182 
183 	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
184 						nft_rhash_params);
185 	if (IS_ERR(prev))
186 		return PTR_ERR(prev);
187 	if (prev) {
188 		*elem_priv = &prev->priv;
189 		return -EEXIST;
190 	}
191 	return 0;
192 }
193 
nft_rhash_activate(const struct net * net,const struct nft_set * set,struct nft_elem_priv * elem_priv)194 static void nft_rhash_activate(const struct net *net, const struct nft_set *set,
195 			       struct nft_elem_priv *elem_priv)
196 {
197 	struct nft_rhash_elem *he = nft_elem_priv_cast(elem_priv);
198 
199 	nft_clear(net, &he->ext);
200 }
201 
nft_rhash_flush(const struct net * net,const struct nft_set * set,struct nft_elem_priv * elem_priv)202 static void nft_rhash_flush(const struct net *net,
203 			    const struct nft_set *set,
204 			    struct nft_elem_priv *elem_priv)
205 {
206 	struct nft_rhash_elem *he = nft_elem_priv_cast(elem_priv);
207 
208 	nft_set_elem_change_active(net, set, &he->ext);
209 }
210 
211 static struct nft_elem_priv *
nft_rhash_deactivate(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem)212 nft_rhash_deactivate(const struct net *net, const struct nft_set *set,
213 		     const struct nft_set_elem *elem)
214 {
215 	struct nft_rhash *priv = nft_set_priv(set);
216 	struct nft_rhash_elem *he;
217 	struct nft_rhash_cmp_arg arg = {
218 		.genmask = nft_genmask_next(net),
219 		.set	 = set,
220 		.key	 = elem->key.val.data,
221 		.tstamp	 = nft_net_tstamp(net),
222 	};
223 
224 	rcu_read_lock();
225 	he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
226 	if (he)
227 		nft_set_elem_change_active(net, set, &he->ext);
228 
229 	rcu_read_unlock();
230 
231 	return &he->priv;
232 }
233 
nft_rhash_remove(const struct net * net,const struct nft_set * set,struct nft_elem_priv * elem_priv)234 static void nft_rhash_remove(const struct net *net,
235 			     const struct nft_set *set,
236 			     struct nft_elem_priv *elem_priv)
237 {
238 	struct nft_rhash_elem *he = nft_elem_priv_cast(elem_priv);
239 	struct nft_rhash *priv = nft_set_priv(set);
240 
241 	rhashtable_remove_fast(&priv->ht, &he->node, nft_rhash_params);
242 }
243 
nft_rhash_delete(const struct nft_set * set,const u32 * key)244 static bool nft_rhash_delete(const struct nft_set *set,
245 			     const u32 *key)
246 {
247 	struct nft_rhash *priv = nft_set_priv(set);
248 	struct nft_rhash_cmp_arg arg = {
249 		.genmask = NFT_GENMASK_ANY,
250 		.set = set,
251 		.key = key,
252 	};
253 	struct nft_rhash_elem *he;
254 
255 	he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
256 	if (he == NULL)
257 		return false;
258 
259 	nft_set_elem_dead(&he->ext);
260 
261 	return true;
262 }
263 
nft_rhash_walk(const struct nft_ctx * ctx,struct nft_set * set,struct nft_set_iter * iter)264 static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set,
265 			   struct nft_set_iter *iter)
266 {
267 	struct nft_rhash *priv = nft_set_priv(set);
268 	struct nft_rhash_elem *he;
269 	struct rhashtable_iter hti;
270 
271 	rhashtable_walk_enter(&priv->ht, &hti);
272 	rhashtable_walk_start(&hti);
273 
274 	while ((he = rhashtable_walk_next(&hti))) {
275 		if (IS_ERR(he)) {
276 			if (PTR_ERR(he) != -EAGAIN) {
277 				iter->err = PTR_ERR(he);
278 				break;
279 			}
280 
281 			continue;
282 		}
283 
284 		if (iter->count < iter->skip)
285 			goto cont;
286 
287 		iter->err = iter->fn(ctx, set, iter, &he->priv);
288 		if (iter->err < 0)
289 			break;
290 
291 cont:
292 		iter->count++;
293 	}
294 	rhashtable_walk_stop(&hti);
295 	rhashtable_walk_exit(&hti);
296 }
297 
nft_rhash_expr_needs_gc_run(const struct nft_set * set,struct nft_set_ext * ext)298 static bool nft_rhash_expr_needs_gc_run(const struct nft_set *set,
299 					struct nft_set_ext *ext)
300 {
301 	struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext);
302 	struct nft_expr *expr;
303 	u32 size;
304 
305 	nft_setelem_expr_foreach(expr, elem_expr, size) {
306 		if (expr->ops->gc &&
307 		    expr->ops->gc(read_pnet(&set->net), expr) &&
308 		    set->flags & NFT_SET_EVAL)
309 			return true;
310 	}
311 
312 	return false;
313 }
314 
nft_rhash_gc(struct work_struct * work)315 static void nft_rhash_gc(struct work_struct *work)
316 {
317 	struct nftables_pernet *nft_net;
318 	struct nft_set *set;
319 	struct nft_rhash_elem *he;
320 	struct nft_rhash *priv;
321 	struct rhashtable_iter hti;
322 	struct nft_trans_gc *gc;
323 	struct net *net;
324 	u32 gc_seq;
325 
326 	priv = container_of(work, struct nft_rhash, gc_work.work);
327 	set  = nft_set_container_of(priv);
328 	net  = read_pnet(&set->net);
329 	nft_net = nft_pernet(net);
330 	gc_seq = READ_ONCE(nft_net->gc_seq);
331 
332 	if (nft_set_gc_is_pending(set))
333 		goto done;
334 
335 	gc = nft_trans_gc_alloc(set, gc_seq, GFP_KERNEL);
336 	if (!gc)
337 		goto done;
338 
339 	/* Elements never collected use a zero gc worker sequence number. */
340 	if (unlikely(++priv->wq_gc_seq == 0))
341 		priv->wq_gc_seq++;
342 
343 	rhashtable_walk_enter(&priv->ht, &hti);
344 	rhashtable_walk_start(&hti);
345 
346 	while ((he = rhashtable_walk_next(&hti))) {
347 		if (IS_ERR(he)) {
348 			nft_trans_gc_destroy(gc);
349 			gc = NULL;
350 			goto try_later;
351 		}
352 
353 		/* Ruleset has been updated, try later. */
354 		if (READ_ONCE(nft_net->gc_seq) != gc_seq) {
355 			nft_trans_gc_destroy(gc);
356 			gc = NULL;
357 			goto try_later;
358 		}
359 
360 		/* rhashtable walk is unstable, already seen in this gc run?
361 		 * Then, skip this element. In case of (unlikely) sequence
362 		 * wraparound and stale element wq_gc_seq, next gc run will
363 		 * just find this expired element.
364 		 */
365 		if (he->wq_gc_seq == priv->wq_gc_seq)
366 			continue;
367 
368 		if (nft_set_elem_is_dead(&he->ext))
369 			goto dead_elem;
370 
371 		if (nft_set_ext_exists(&he->ext, NFT_SET_EXT_EXPRESSIONS) &&
372 		    nft_rhash_expr_needs_gc_run(set, &he->ext))
373 			goto needs_gc_run;
374 
375 		if (!nft_set_elem_expired(&he->ext))
376 			continue;
377 needs_gc_run:
378 		nft_set_elem_dead(&he->ext);
379 dead_elem:
380 		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
381 		if (!gc)
382 			goto try_later;
383 
384 		/* annotate gc sequence for this attempt. */
385 		he->wq_gc_seq = priv->wq_gc_seq;
386 		nft_trans_gc_elem_add(gc, he);
387 	}
388 
389 	gc = nft_trans_gc_catchall_async(gc, gc_seq);
390 
391 try_later:
392 	/* catchall list iteration requires rcu read side lock. */
393 	rhashtable_walk_stop(&hti);
394 	rhashtable_walk_exit(&hti);
395 
396 	if (gc)
397 		nft_trans_gc_queue_async_done(gc);
398 
399 done:
400 	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
401 			   nft_set_gc_interval(set));
402 }
403 
nft_rhash_privsize(const struct nlattr * const nla[],const struct nft_set_desc * desc)404 static u64 nft_rhash_privsize(const struct nlattr * const nla[],
405 			      const struct nft_set_desc *desc)
406 {
407 	return sizeof(struct nft_rhash);
408 }
409 
nft_rhash_gc_init(const struct nft_set * set)410 static void nft_rhash_gc_init(const struct nft_set *set)
411 {
412 	struct nft_rhash *priv = nft_set_priv(set);
413 
414 	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
415 			   nft_set_gc_interval(set));
416 }
417 
nft_rhash_init(const struct nft_set * set,const struct nft_set_desc * desc,const struct nlattr * const tb[])418 static int nft_rhash_init(const struct nft_set *set,
419 			  const struct nft_set_desc *desc,
420 			  const struct nlattr * const tb[])
421 {
422 	struct nft_rhash *priv = nft_set_priv(set);
423 	struct rhashtable_params params = nft_rhash_params;
424 	int err;
425 
426 	BUILD_BUG_ON(offsetof(struct nft_rhash_elem, priv) != 0);
427 
428 	params.nelem_hint = desc->size ?: NFT_RHASH_ELEMENT_HINT;
429 	params.key_len	  = set->klen;
430 
431 	err = rhashtable_init(&priv->ht, &params);
432 	if (err < 0)
433 		return err;
434 
435 	INIT_DEFERRABLE_WORK(&priv->gc_work, nft_rhash_gc);
436 	if (set->flags & (NFT_SET_TIMEOUT | NFT_SET_EVAL))
437 		nft_rhash_gc_init(set);
438 
439 	return 0;
440 }
441 
442 struct nft_rhash_ctx {
443 	const struct nft_ctx	ctx;
444 	const struct nft_set	*set;
445 };
446 
nft_rhash_elem_destroy(void * ptr,void * arg)447 static void nft_rhash_elem_destroy(void *ptr, void *arg)
448 {
449 	struct nft_rhash_ctx *rhash_ctx = arg;
450 	struct nft_rhash_elem *he = ptr;
451 
452 	nf_tables_set_elem_destroy(&rhash_ctx->ctx, rhash_ctx->set, &he->priv);
453 }
454 
nft_rhash_destroy(const struct nft_ctx * ctx,const struct nft_set * set)455 static void nft_rhash_destroy(const struct nft_ctx *ctx,
456 			      const struct nft_set *set)
457 {
458 	struct nft_rhash *priv = nft_set_priv(set);
459 	struct nft_rhash_ctx rhash_ctx = {
460 		.ctx	= *ctx,
461 		.set	= set,
462 	};
463 
464 	cancel_delayed_work_sync(&priv->gc_work);
465 	rhashtable_free_and_destroy(&priv->ht, nft_rhash_elem_destroy,
466 				    (void *)&rhash_ctx);
467 }
468 
469 /* Number of buckets is stored in u32, so cap our result to 1U<<31 */
470 #define NFT_MAX_BUCKETS (1U << 31)
471 
nft_hash_buckets(u32 size)472 static u32 nft_hash_buckets(u32 size)
473 {
474 	u64 val = div_u64((u64)size * 4, 3);
475 
476 	if (val >= NFT_MAX_BUCKETS)
477 		return NFT_MAX_BUCKETS;
478 
479 	return roundup_pow_of_two(val);
480 }
481 
nft_rhash_estimate(const struct nft_set_desc * desc,u32 features,struct nft_set_estimate * est)482 static bool nft_rhash_estimate(const struct nft_set_desc *desc, u32 features,
483 			       struct nft_set_estimate *est)
484 {
485 	est->size   = ~0;
486 	est->lookup = NFT_SET_CLASS_O_1;
487 	est->space  = NFT_SET_CLASS_O_N;
488 
489 	return true;
490 }
491 
492 struct nft_hash {
493 	u32				seed;
494 	u32				buckets;
495 	struct hlist_head		table[];
496 };
497 
498 struct nft_hash_elem {
499 	struct nft_elem_priv		priv;
500 	struct hlist_node		node;
501 	struct nft_set_ext		ext;
502 };
503 
504 INDIRECT_CALLABLE_SCOPE
505 const struct nft_set_ext *
nft_hash_lookup(const struct net * net,const struct nft_set * set,const u32 * key)506 nft_hash_lookup(const struct net *net, const struct nft_set *set,
507 		const u32 *key)
508 {
509 	struct nft_hash *priv = nft_set_priv(set);
510 	u8 genmask = nft_genmask_cur(net);
511 	const struct nft_hash_elem *he;
512 	u32 hash;
513 
514 	hash = jhash(key, set->klen, priv->seed);
515 	hash = reciprocal_scale(hash, priv->buckets);
516 	hlist_for_each_entry_rcu(he, &priv->table[hash], node) {
517 		if (!memcmp(nft_set_ext_key(&he->ext), key, set->klen) &&
518 		    nft_set_elem_active(&he->ext, genmask))
519 			return &he->ext;
520 	}
521 	return NULL;
522 }
523 
524 static struct nft_elem_priv *
nft_hash_get(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem,unsigned int flags)525 nft_hash_get(const struct net *net, const struct nft_set *set,
526 	     const struct nft_set_elem *elem, unsigned int flags)
527 {
528 	struct nft_hash *priv = nft_set_priv(set);
529 	u8 genmask = nft_genmask_cur(net);
530 	struct nft_hash_elem *he;
531 	u32 hash;
532 
533 	hash = jhash(elem->key.val.data, set->klen, priv->seed);
534 	hash = reciprocal_scale(hash, priv->buckets);
535 	hlist_for_each_entry_rcu(he, &priv->table[hash], node) {
536 		if (!memcmp(nft_set_ext_key(&he->ext), elem->key.val.data, set->klen) &&
537 		    nft_set_elem_active(&he->ext, genmask))
538 			return &he->priv;
539 	}
540 	return ERR_PTR(-ENOENT);
541 }
542 
543 INDIRECT_CALLABLE_SCOPE
544 const struct nft_set_ext *
nft_hash_lookup_fast(const struct net * net,const struct nft_set * set,const u32 * key)545 nft_hash_lookup_fast(const struct net *net, const struct nft_set *set,
546 		     const u32 *key)
547 {
548 	struct nft_hash *priv = nft_set_priv(set);
549 	u8 genmask = nft_genmask_cur(net);
550 	const struct nft_hash_elem *he;
551 	u32 hash, k1, k2;
552 
553 	k1 = *key;
554 	hash = jhash_1word(k1, priv->seed);
555 	hash = reciprocal_scale(hash, priv->buckets);
556 	hlist_for_each_entry_rcu(he, &priv->table[hash], node) {
557 		k2 = *(u32 *)nft_set_ext_key(&he->ext)->data;
558 		if (k1 == k2 &&
559 		    nft_set_elem_active(&he->ext, genmask))
560 			return &he->ext;
561 	}
562 	return NULL;
563 }
564 
nft_jhash(const struct nft_set * set,const struct nft_hash * priv,const struct nft_set_ext * ext)565 static u32 nft_jhash(const struct nft_set *set, const struct nft_hash *priv,
566 		     const struct nft_set_ext *ext)
567 {
568 	const struct nft_data *key = nft_set_ext_key(ext);
569 	u32 hash, k1;
570 
571 	if (set->klen == 4) {
572 		k1 = *(u32 *)key;
573 		hash = jhash_1word(k1, priv->seed);
574 	} else {
575 		hash = jhash(key, set->klen, priv->seed);
576 	}
577 	hash = reciprocal_scale(hash, priv->buckets);
578 
579 	return hash;
580 }
581 
nft_hash_insert(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem,struct nft_elem_priv ** elem_priv)582 static int nft_hash_insert(const struct net *net, const struct nft_set *set,
583 			   const struct nft_set_elem *elem,
584 			   struct nft_elem_priv **elem_priv)
585 {
586 	struct nft_hash_elem *this = nft_elem_priv_cast(elem->priv), *he;
587 	struct nft_hash *priv = nft_set_priv(set);
588 	u8 genmask = nft_genmask_next(net);
589 	u32 hash;
590 
591 	hash = nft_jhash(set, priv, &this->ext);
592 	hlist_for_each_entry(he, &priv->table[hash], node) {
593 		if (!memcmp(nft_set_ext_key(&this->ext),
594 			    nft_set_ext_key(&he->ext), set->klen) &&
595 		    nft_set_elem_active(&he->ext, genmask)) {
596 			*elem_priv = &he->priv;
597 			return -EEXIST;
598 		}
599 	}
600 	hlist_add_head_rcu(&this->node, &priv->table[hash]);
601 	return 0;
602 }
603 
nft_hash_activate(const struct net * net,const struct nft_set * set,struct nft_elem_priv * elem_priv)604 static void nft_hash_activate(const struct net *net, const struct nft_set *set,
605 			      struct nft_elem_priv *elem_priv)
606 {
607 	struct nft_hash_elem *he = nft_elem_priv_cast(elem_priv);
608 
609 	nft_clear(net, &he->ext);
610 }
611 
nft_hash_flush(const struct net * net,const struct nft_set * set,struct nft_elem_priv * elem_priv)612 static void nft_hash_flush(const struct net *net,
613 			   const struct nft_set *set,
614 			   struct nft_elem_priv *elem_priv)
615 {
616 	struct nft_hash_elem *he = nft_elem_priv_cast(elem_priv);
617 
618 	nft_set_elem_change_active(net, set, &he->ext);
619 }
620 
621 static struct nft_elem_priv *
nft_hash_deactivate(const struct net * net,const struct nft_set * set,const struct nft_set_elem * elem)622 nft_hash_deactivate(const struct net *net, const struct nft_set *set,
623 		    const struct nft_set_elem *elem)
624 {
625 	struct nft_hash_elem *this = nft_elem_priv_cast(elem->priv), *he;
626 	struct nft_hash *priv = nft_set_priv(set);
627 	u8 genmask = nft_genmask_next(net);
628 	u32 hash;
629 
630 	hash = nft_jhash(set, priv, &this->ext);
631 	hlist_for_each_entry(he, &priv->table[hash], node) {
632 		if (!memcmp(nft_set_ext_key(&he->ext), &elem->key.val,
633 			    set->klen) &&
634 		    nft_set_elem_active(&he->ext, genmask)) {
635 			nft_set_elem_change_active(net, set, &he->ext);
636 			return &he->priv;
637 		}
638 	}
639 	return NULL;
640 }
641 
nft_hash_remove(const struct net * net,const struct nft_set * set,struct nft_elem_priv * elem_priv)642 static void nft_hash_remove(const struct net *net,
643 			    const struct nft_set *set,
644 			    struct nft_elem_priv *elem_priv)
645 {
646 	struct nft_hash_elem *he = nft_elem_priv_cast(elem_priv);
647 
648 	hlist_del_rcu(&he->node);
649 }
650 
nft_hash_walk(const struct nft_ctx * ctx,struct nft_set * set,struct nft_set_iter * iter)651 static void nft_hash_walk(const struct nft_ctx *ctx, struct nft_set *set,
652 			  struct nft_set_iter *iter)
653 {
654 	struct nft_hash *priv = nft_set_priv(set);
655 	struct nft_hash_elem *he;
656 	int i;
657 
658 	for (i = 0; i < priv->buckets; i++) {
659 		hlist_for_each_entry_rcu(he, &priv->table[i], node,
660 					 lockdep_is_held(&nft_pernet(ctx->net)->commit_mutex)) {
661 			if (iter->count < iter->skip)
662 				goto cont;
663 
664 			iter->err = iter->fn(ctx, set, iter, &he->priv);
665 			if (iter->err < 0)
666 				return;
667 cont:
668 			iter->count++;
669 		}
670 	}
671 }
672 
nft_hash_privsize(const struct nlattr * const nla[],const struct nft_set_desc * desc)673 static u64 nft_hash_privsize(const struct nlattr * const nla[],
674 			     const struct nft_set_desc *desc)
675 {
676 	return sizeof(struct nft_hash) +
677 	       (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head);
678 }
679 
nft_hash_init(const struct nft_set * set,const struct nft_set_desc * desc,const struct nlattr * const tb[])680 static int nft_hash_init(const struct nft_set *set,
681 			 const struct nft_set_desc *desc,
682 			 const struct nlattr * const tb[])
683 {
684 	struct nft_hash *priv = nft_set_priv(set);
685 
686 	priv->buckets = nft_hash_buckets(desc->size);
687 	get_random_bytes(&priv->seed, sizeof(priv->seed));
688 
689 	return 0;
690 }
691 
nft_hash_destroy(const struct nft_ctx * ctx,const struct nft_set * set)692 static void nft_hash_destroy(const struct nft_ctx *ctx,
693 			     const struct nft_set *set)
694 {
695 	struct nft_hash *priv = nft_set_priv(set);
696 	struct nft_hash_elem *he;
697 	struct hlist_node *next;
698 	int i;
699 
700 	for (i = 0; i < priv->buckets; i++) {
701 		hlist_for_each_entry_safe(he, next, &priv->table[i], node) {
702 			hlist_del_rcu(&he->node);
703 			nf_tables_set_elem_destroy(ctx, set, &he->priv);
704 		}
705 	}
706 }
707 
nft_hash_estimate(const struct nft_set_desc * desc,u32 features,struct nft_set_estimate * est)708 static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
709 			      struct nft_set_estimate *est)
710 {
711 	if (!desc->size)
712 		return false;
713 
714 	if (desc->klen == 4)
715 		return false;
716 
717 	est->size   = sizeof(struct nft_hash) +
718 		      (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
719 		      (u64)desc->size * sizeof(struct nft_hash_elem);
720 	est->lookup = NFT_SET_CLASS_O_1;
721 	est->space  = NFT_SET_CLASS_O_N;
722 
723 	return true;
724 }
725 
nft_hash_fast_estimate(const struct nft_set_desc * desc,u32 features,struct nft_set_estimate * est)726 static bool nft_hash_fast_estimate(const struct nft_set_desc *desc, u32 features,
727 				   struct nft_set_estimate *est)
728 {
729 	if (!desc->size)
730 		return false;
731 
732 	if (desc->klen != 4)
733 		return false;
734 
735 	est->size   = sizeof(struct nft_hash) +
736 		      (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
737 		      (u64)desc->size * sizeof(struct nft_hash_elem);
738 	est->lookup = NFT_SET_CLASS_O_1;
739 	est->space  = NFT_SET_CLASS_O_N;
740 
741 	return true;
742 }
743 
744 const struct nft_set_type nft_set_rhash_type = {
745 	.features	= NFT_SET_MAP | NFT_SET_OBJECT |
746 			  NFT_SET_TIMEOUT | NFT_SET_EVAL,
747 	.ops		= {
748 		.privsize       = nft_rhash_privsize,
749 		.elemsize	= offsetof(struct nft_rhash_elem, ext),
750 		.estimate	= nft_rhash_estimate,
751 		.init		= nft_rhash_init,
752 		.gc_init	= nft_rhash_gc_init,
753 		.destroy	= nft_rhash_destroy,
754 		.insert		= nft_rhash_insert,
755 		.activate	= nft_rhash_activate,
756 		.deactivate	= nft_rhash_deactivate,
757 		.flush		= nft_rhash_flush,
758 		.remove		= nft_rhash_remove,
759 		.lookup		= nft_rhash_lookup,
760 		.update		= nft_rhash_update,
761 		.delete		= nft_rhash_delete,
762 		.walk		= nft_rhash_walk,
763 		.get		= nft_rhash_get,
764 	},
765 };
766 
767 const struct nft_set_type nft_set_hash_type = {
768 	.features	= NFT_SET_MAP | NFT_SET_OBJECT,
769 	.ops		= {
770 		.privsize       = nft_hash_privsize,
771 		.elemsize	= offsetof(struct nft_hash_elem, ext),
772 		.estimate	= nft_hash_estimate,
773 		.init		= nft_hash_init,
774 		.destroy	= nft_hash_destroy,
775 		.insert		= nft_hash_insert,
776 		.activate	= nft_hash_activate,
777 		.deactivate	= nft_hash_deactivate,
778 		.flush		= nft_hash_flush,
779 		.remove		= nft_hash_remove,
780 		.lookup		= nft_hash_lookup,
781 		.walk		= nft_hash_walk,
782 		.get		= nft_hash_get,
783 	},
784 };
785 
786 const struct nft_set_type nft_set_hash_fast_type = {
787 	.features	= NFT_SET_MAP | NFT_SET_OBJECT,
788 	.ops		= {
789 		.privsize       = nft_hash_privsize,
790 		.elemsize	= offsetof(struct nft_hash_elem, ext),
791 		.estimate	= nft_hash_fast_estimate,
792 		.init		= nft_hash_init,
793 		.destroy	= nft_hash_destroy,
794 		.insert		= nft_hash_insert,
795 		.activate	= nft_hash_activate,
796 		.deactivate	= nft_hash_deactivate,
797 		.flush		= nft_hash_flush,
798 		.remove		= nft_hash_remove,
799 		.lookup		= nft_hash_lookup_fast,
800 		.walk		= nft_hash_walk,
801 		.get		= nft_hash_get,
802 	},
803 };
804