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