1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
5 * Development of this code funded by Astaro AG (http://www.astaro.com/)
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/list.h>
12 #include <linux/rbtree.h>
13 #include <linux/netlink.h>
14 #include <linux/netfilter.h>
15 #include <linux/netfilter/nf_tables.h>
16 #include <net/netfilter/nf_tables_core.h>
21 seqcount_rwlock_t count;
22 unsigned long last_gc;
25 struct nft_rbtree_elem {
26 struct nft_elem_priv priv;
28 struct nft_set_ext ext;
31 static bool nft_rbtree_interval_end(const struct nft_rbtree_elem *rbe)
33 return nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) &&
34 (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END);
37 static bool nft_rbtree_interval_start(const struct nft_rbtree_elem *rbe)
39 return !nft_rbtree_interval_end(rbe);
42 static int nft_rbtree_cmp(const struct nft_set *set,
43 const struct nft_rbtree_elem *e1,
44 const struct nft_rbtree_elem *e2)
46 return memcmp(nft_set_ext_key(&e1->ext), nft_set_ext_key(&e2->ext),
50 static bool nft_rbtree_elem_expired(const struct nft_rbtree_elem *rbe)
52 return nft_set_elem_expired(&rbe->ext);
55 static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
56 const u32 *key, const struct nft_set_ext **ext,
59 struct nft_rbtree *priv = nft_set_priv(set);
60 const struct nft_rbtree_elem *rbe, *interval = NULL;
61 u8 genmask = nft_genmask_cur(net);
62 const struct rb_node *parent;
65 parent = rcu_dereference_raw(priv->root.rb_node);
66 while (parent != NULL) {
67 if (read_seqcount_retry(&priv->count, seq))
70 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
72 d = memcmp(nft_set_ext_key(&rbe->ext), key, set->klen);
74 parent = rcu_dereference_raw(parent->rb_left);
76 !nft_rbtree_cmp(set, rbe, interval) &&
77 nft_rbtree_interval_end(rbe) &&
78 nft_rbtree_interval_start(interval))
82 parent = rcu_dereference_raw(parent->rb_right);
84 if (!nft_set_elem_active(&rbe->ext, genmask)) {
85 parent = rcu_dereference_raw(parent->rb_left);
89 if (nft_rbtree_elem_expired(rbe))
92 if (nft_rbtree_interval_end(rbe)) {
93 if (nft_set_is_anonymous(set))
95 parent = rcu_dereference_raw(parent->rb_left);
105 if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
106 nft_set_elem_active(&interval->ext, genmask) &&
107 !nft_rbtree_elem_expired(interval) &&
108 nft_rbtree_interval_start(interval)) {
109 *ext = &interval->ext;
116 INDIRECT_CALLABLE_SCOPE
117 bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
118 const u32 *key, const struct nft_set_ext **ext)
120 struct nft_rbtree *priv = nft_set_priv(set);
121 unsigned int seq = read_seqcount_begin(&priv->count);
124 ret = __nft_rbtree_lookup(net, set, key, ext, seq);
125 if (ret || !read_seqcount_retry(&priv->count, seq))
128 read_lock_bh(&priv->lock);
129 seq = read_seqcount_begin(&priv->count);
130 ret = __nft_rbtree_lookup(net, set, key, ext, seq);
131 read_unlock_bh(&priv->lock);
136 static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
137 const u32 *key, struct nft_rbtree_elem **elem,
138 unsigned int seq, unsigned int flags, u8 genmask)
140 struct nft_rbtree_elem *rbe, *interval = NULL;
141 struct nft_rbtree *priv = nft_set_priv(set);
142 const struct rb_node *parent;
146 parent = rcu_dereference_raw(priv->root.rb_node);
147 while (parent != NULL) {
148 if (read_seqcount_retry(&priv->count, seq))
151 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
153 this = nft_set_ext_key(&rbe->ext);
154 d = memcmp(this, key, set->klen);
156 parent = rcu_dereference_raw(parent->rb_left);
157 if (!(flags & NFT_SET_ELEM_INTERVAL_END))
160 parent = rcu_dereference_raw(parent->rb_right);
161 if (flags & NFT_SET_ELEM_INTERVAL_END)
164 if (!nft_set_elem_active(&rbe->ext, genmask)) {
165 parent = rcu_dereference_raw(parent->rb_left);
169 if (nft_set_elem_expired(&rbe->ext))
172 if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) ||
173 (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) ==
174 (flags & NFT_SET_ELEM_INTERVAL_END)) {
179 if (nft_rbtree_interval_end(rbe))
182 parent = rcu_dereference_raw(parent->rb_left);
186 if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
187 nft_set_elem_active(&interval->ext, genmask) &&
188 !nft_set_elem_expired(&interval->ext) &&
189 ((!nft_rbtree_interval_end(interval) &&
190 !(flags & NFT_SET_ELEM_INTERVAL_END)) ||
191 (nft_rbtree_interval_end(interval) &&
192 (flags & NFT_SET_ELEM_INTERVAL_END)))) {
200 static struct nft_elem_priv *
201 nft_rbtree_get(const struct net *net, const struct nft_set *set,
202 const struct nft_set_elem *elem, unsigned int flags)
204 struct nft_rbtree *priv = nft_set_priv(set);
205 unsigned int seq = read_seqcount_begin(&priv->count);
206 struct nft_rbtree_elem *rbe = ERR_PTR(-ENOENT);
207 const u32 *key = (const u32 *)&elem->key.val;
208 u8 genmask = nft_genmask_cur(net);
211 ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
212 if (ret || !read_seqcount_retry(&priv->count, seq))
215 read_lock_bh(&priv->lock);
216 seq = read_seqcount_begin(&priv->count);
217 ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
218 read_unlock_bh(&priv->lock);
221 return ERR_PTR(-ENOENT);
226 static void nft_rbtree_gc_elem_remove(struct net *net, struct nft_set *set,
227 struct nft_rbtree *priv,
228 struct nft_rbtree_elem *rbe)
230 lockdep_assert_held_write(&priv->lock);
231 nft_setelem_data_deactivate(net, set, &rbe->priv);
232 rb_erase(&rbe->node, &priv->root);
235 static const struct nft_rbtree_elem *
236 nft_rbtree_gc_elem(const struct nft_set *__set, struct nft_rbtree *priv,
237 struct nft_rbtree_elem *rbe)
239 struct nft_set *set = (struct nft_set *)__set;
240 struct rb_node *prev = rb_prev(&rbe->node);
241 struct net *net = read_pnet(&set->net);
242 struct nft_rbtree_elem *rbe_prev;
243 struct nft_trans_gc *gc;
245 gc = nft_trans_gc_alloc(set, 0, GFP_ATOMIC);
247 return ERR_PTR(-ENOMEM);
249 /* search for end interval coming before this element.
250 * end intervals don't carry a timeout extension, they
251 * are coupled with the interval start element.
254 rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
255 if (nft_rbtree_interval_end(rbe_prev) &&
256 nft_set_elem_active(&rbe_prev->ext, NFT_GENMASK_ANY))
259 prev = rb_prev(prev);
264 rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
265 nft_rbtree_gc_elem_remove(net, set, priv, rbe_prev);
267 /* There is always room in this trans gc for this element,
268 * memory allocation never actually happens, hence, the warning
269 * splat in such case. No need to set NFT_SET_ELEM_DEAD_BIT,
270 * this is synchronous gc which never fails.
272 gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
273 if (WARN_ON_ONCE(!gc))
274 return ERR_PTR(-ENOMEM);
276 nft_trans_gc_elem_add(gc, rbe_prev);
279 nft_rbtree_gc_elem_remove(net, set, priv, rbe);
280 gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
281 if (WARN_ON_ONCE(!gc))
282 return ERR_PTR(-ENOMEM);
284 nft_trans_gc_elem_add(gc, rbe);
286 nft_trans_gc_queue_sync_done(gc);
291 static bool nft_rbtree_update_first(const struct nft_set *set,
292 struct nft_rbtree_elem *rbe,
293 struct rb_node *first)
295 struct nft_rbtree_elem *first_elem;
297 first_elem = rb_entry(first, struct nft_rbtree_elem, node);
298 /* this element is closest to where the new element is to be inserted:
299 * update the first element for the node list path.
301 if (nft_rbtree_cmp(set, rbe, first_elem) < 0)
307 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
308 struct nft_rbtree_elem *new,
309 struct nft_elem_priv **elem_priv)
311 struct nft_rbtree_elem *rbe, *rbe_le = NULL, *rbe_ge = NULL;
312 struct rb_node *node, *next, *parent, **p, *first = NULL;
313 struct nft_rbtree *priv = nft_set_priv(set);
314 u8 cur_genmask = nft_genmask_cur(net);
315 u8 genmask = nft_genmask_next(net);
316 u64 tstamp = nft_net_tstamp(net);
319 /* Descend the tree to search for an existing element greater than the
320 * key value to insert that is greater than the new element. This is the
321 * first element to walk the ordered elements to find possible overlap.
324 p = &priv->root.rb_node;
327 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
328 d = nft_rbtree_cmp(set, rbe, new);
331 p = &parent->rb_left;
334 nft_rbtree_update_first(set, rbe, first))
337 p = &parent->rb_right;
339 if (nft_rbtree_interval_end(rbe))
340 p = &parent->rb_left;
342 p = &parent->rb_right;
347 first = rb_first(&priv->root);
349 /* Detect overlap by going through the list of valid tree nodes.
350 * Values stored in the tree are in reversed order, starting from
351 * highest to lowest value.
353 for (node = first; node != NULL; node = next) {
354 next = rb_next(node);
356 rbe = rb_entry(node, struct nft_rbtree_elem, node);
358 if (!nft_set_elem_active(&rbe->ext, genmask))
361 /* perform garbage collection to avoid bogus overlap reports
362 * but skip new elements in this transaction.
364 if (__nft_set_elem_expired(&rbe->ext, tstamp) &&
365 nft_set_elem_active(&rbe->ext, cur_genmask)) {
366 const struct nft_rbtree_elem *removed_end;
368 removed_end = nft_rbtree_gc_elem(set, priv, rbe);
369 if (IS_ERR(removed_end))
370 return PTR_ERR(removed_end);
372 if (removed_end == rbe_le || removed_end == rbe_ge)
378 d = nft_rbtree_cmp(set, rbe, new);
380 /* Matching end element: no need to look for an
381 * overlapping greater or equal element.
383 if (nft_rbtree_interval_end(rbe)) {
388 /* first element that is greater or equal to key value. */
394 /* this is a closer more or equal element, update it. */
395 if (nft_rbtree_cmp(set, rbe_ge, new) != 0) {
400 /* element is equal to key value, make sure flags are
401 * the same, an existing more or equal start element
402 * must not be replaced by more or equal end element.
404 if ((nft_rbtree_interval_start(new) &&
405 nft_rbtree_interval_start(rbe_ge)) ||
406 (nft_rbtree_interval_end(new) &&
407 nft_rbtree_interval_end(rbe_ge))) {
412 /* annotate element greater than the new element. */
416 /* annotate element less than the new element. */
422 /* - new start element matching existing start element: full overlap
423 * reported as -EEXIST, cleared by caller if NLM_F_EXCL is not given.
425 if (rbe_ge && !nft_rbtree_cmp(set, new, rbe_ge) &&
426 nft_rbtree_interval_start(rbe_ge) == nft_rbtree_interval_start(new)) {
427 *elem_priv = &rbe_ge->priv;
431 /* - new end element matching existing end element: full overlap
432 * reported as -EEXIST, cleared by caller if NLM_F_EXCL is not given.
434 if (rbe_le && !nft_rbtree_cmp(set, new, rbe_le) &&
435 nft_rbtree_interval_end(rbe_le) == nft_rbtree_interval_end(new)) {
436 *elem_priv = &rbe_le->priv;
440 /* - new start element with existing closest, less or equal key value
441 * being a start element: partial overlap, reported as -ENOTEMPTY.
442 * Anonymous sets allow for two consecutive start element since they
443 * are constant, skip them to avoid bogus overlap reports.
445 if (!nft_set_is_anonymous(set) && rbe_le &&
446 nft_rbtree_interval_start(rbe_le) && nft_rbtree_interval_start(new))
449 /* - new end element with existing closest, less or equal key value
450 * being a end element: partial overlap, reported as -ENOTEMPTY.
453 nft_rbtree_interval_end(rbe_le) && nft_rbtree_interval_end(new))
456 /* - new end element with existing closest, greater or equal key value
457 * being an end element: partial overlap, reported as -ENOTEMPTY
460 nft_rbtree_interval_end(rbe_ge) && nft_rbtree_interval_end(new))
463 /* Accepted element: pick insertion point depending on key value */
465 p = &priv->root.rb_node;
468 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
469 d = nft_rbtree_cmp(set, rbe, new);
472 p = &parent->rb_left;
474 p = &parent->rb_right;
475 else if (nft_rbtree_interval_end(rbe))
476 p = &parent->rb_left;
478 p = &parent->rb_right;
481 rb_link_node_rcu(&new->node, parent, p);
482 rb_insert_color(&new->node, &priv->root);
486 static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
487 const struct nft_set_elem *elem,
488 struct nft_elem_priv **elem_priv)
490 struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem->priv);
491 struct nft_rbtree *priv = nft_set_priv(set);
495 if (fatal_signal_pending(current))
500 write_lock_bh(&priv->lock);
501 write_seqcount_begin(&priv->count);
502 err = __nft_rbtree_insert(net, set, rbe, elem_priv);
503 write_seqcount_end(&priv->count);
504 write_unlock_bh(&priv->lock);
505 } while (err == -EAGAIN);
510 static void nft_rbtree_erase(struct nft_rbtree *priv, struct nft_rbtree_elem *rbe)
512 write_lock_bh(&priv->lock);
513 write_seqcount_begin(&priv->count);
514 rb_erase(&rbe->node, &priv->root);
515 write_seqcount_end(&priv->count);
516 write_unlock_bh(&priv->lock);
519 static void nft_rbtree_remove(const struct net *net,
520 const struct nft_set *set,
521 struct nft_elem_priv *elem_priv)
523 struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem_priv);
524 struct nft_rbtree *priv = nft_set_priv(set);
526 nft_rbtree_erase(priv, rbe);
529 static void nft_rbtree_activate(const struct net *net,
530 const struct nft_set *set,
531 struct nft_elem_priv *elem_priv)
533 struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem_priv);
535 nft_clear(net, &rbe->ext);
538 static void nft_rbtree_flush(const struct net *net,
539 const struct nft_set *set,
540 struct nft_elem_priv *elem_priv)
542 struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem_priv);
544 nft_set_elem_change_active(net, set, &rbe->ext);
547 static struct nft_elem_priv *
548 nft_rbtree_deactivate(const struct net *net, const struct nft_set *set,
549 const struct nft_set_elem *elem)
551 struct nft_rbtree_elem *rbe, *this = nft_elem_priv_cast(elem->priv);
552 const struct nft_rbtree *priv = nft_set_priv(set);
553 const struct rb_node *parent = priv->root.rb_node;
554 u8 genmask = nft_genmask_next(net);
555 u64 tstamp = nft_net_tstamp(net);
558 while (parent != NULL) {
559 rbe = rb_entry(parent, struct nft_rbtree_elem, node);
561 d = memcmp(nft_set_ext_key(&rbe->ext), &elem->key.val,
564 parent = parent->rb_left;
566 parent = parent->rb_right;
568 if (nft_rbtree_interval_end(rbe) &&
569 nft_rbtree_interval_start(this)) {
570 parent = parent->rb_left;
572 } else if (nft_rbtree_interval_start(rbe) &&
573 nft_rbtree_interval_end(this)) {
574 parent = parent->rb_right;
576 } else if (__nft_set_elem_expired(&rbe->ext, tstamp)) {
578 } else if (!nft_set_elem_active(&rbe->ext, genmask)) {
579 parent = parent->rb_left;
582 nft_rbtree_flush(net, set, &rbe->priv);
589 static void nft_rbtree_walk(const struct nft_ctx *ctx,
591 struct nft_set_iter *iter)
593 struct nft_rbtree *priv = nft_set_priv(set);
594 struct nft_rbtree_elem *rbe;
595 struct rb_node *node;
597 read_lock_bh(&priv->lock);
598 for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
599 rbe = rb_entry(node, struct nft_rbtree_elem, node);
601 if (iter->count < iter->skip)
604 iter->err = iter->fn(ctx, set, iter, &rbe->priv);
606 read_unlock_bh(&priv->lock);
612 read_unlock_bh(&priv->lock);
615 static void nft_rbtree_gc_remove(struct net *net, struct nft_set *set,
616 struct nft_rbtree *priv,
617 struct nft_rbtree_elem *rbe)
619 nft_setelem_data_deactivate(net, set, &rbe->priv);
620 nft_rbtree_erase(priv, rbe);
623 static void nft_rbtree_gc(struct nft_set *set)
625 struct nft_rbtree *priv = nft_set_priv(set);
626 struct nft_rbtree_elem *rbe, *rbe_end = NULL;
627 struct net *net = read_pnet(&set->net);
628 u64 tstamp = nft_net_tstamp(net);
629 struct rb_node *node, *next;
630 struct nft_trans_gc *gc;
632 set = nft_set_container_of(priv);
633 net = read_pnet(&set->net);
635 gc = nft_trans_gc_alloc(set, 0, GFP_KERNEL);
639 for (node = rb_first(&priv->root); node ; node = next) {
640 next = rb_next(node);
642 rbe = rb_entry(node, struct nft_rbtree_elem, node);
644 /* elements are reversed in the rbtree for historical reasons,
645 * from highest to lowest value, that is why end element is
646 * always visited before the start element.
648 if (nft_rbtree_interval_end(rbe)) {
652 if (!__nft_set_elem_expired(&rbe->ext, tstamp))
655 gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL);
659 /* end element needs to be removed first, it has
660 * no timeout extension.
663 nft_rbtree_gc_remove(net, set, priv, rbe_end);
664 nft_trans_gc_elem_add(gc, rbe_end);
668 gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL);
672 nft_rbtree_gc_remove(net, set, priv, rbe);
673 nft_trans_gc_elem_add(gc, rbe);
679 gc = nft_trans_gc_catchall_sync(gc);
680 nft_trans_gc_queue_sync_done(gc);
681 priv->last_gc = jiffies;
685 static u64 nft_rbtree_privsize(const struct nlattr * const nla[],
686 const struct nft_set_desc *desc)
688 return sizeof(struct nft_rbtree);
691 static int nft_rbtree_init(const struct nft_set *set,
692 const struct nft_set_desc *desc,
693 const struct nlattr * const nla[])
695 struct nft_rbtree *priv = nft_set_priv(set);
697 BUILD_BUG_ON(offsetof(struct nft_rbtree_elem, priv) != 0);
699 rwlock_init(&priv->lock);
700 seqcount_rwlock_init(&priv->count, &priv->lock);
701 priv->root = RB_ROOT;
706 static void nft_rbtree_destroy(const struct nft_ctx *ctx,
707 const struct nft_set *set)
709 struct nft_rbtree *priv = nft_set_priv(set);
710 struct nft_rbtree_elem *rbe;
711 struct rb_node *node;
713 while ((node = priv->root.rb_node) != NULL) {
714 rb_erase(node, &priv->root);
715 rbe = rb_entry(node, struct nft_rbtree_elem, node);
716 nf_tables_set_elem_destroy(ctx, set, &rbe->priv);
720 static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
721 struct nft_set_estimate *est)
723 if (desc->field_count > 1)
727 est->size = sizeof(struct nft_rbtree) +
728 desc->size * sizeof(struct nft_rbtree_elem);
732 est->lookup = NFT_SET_CLASS_O_LOG_N;
733 est->space = NFT_SET_CLASS_O_N;
738 static void nft_rbtree_commit(struct nft_set *set)
740 struct nft_rbtree *priv = nft_set_priv(set);
742 if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set)))
746 static void nft_rbtree_gc_init(const struct nft_set *set)
748 struct nft_rbtree *priv = nft_set_priv(set);
750 priv->last_gc = jiffies;
753 const struct nft_set_type nft_set_rbtree_type = {
754 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
756 .privsize = nft_rbtree_privsize,
757 .elemsize = offsetof(struct nft_rbtree_elem, ext),
758 .estimate = nft_rbtree_estimate,
759 .init = nft_rbtree_init,
760 .destroy = nft_rbtree_destroy,
761 .insert = nft_rbtree_insert,
762 .remove = nft_rbtree_remove,
763 .deactivate = nft_rbtree_deactivate,
764 .flush = nft_rbtree_flush,
765 .activate = nft_rbtree_activate,
766 .commit = nft_rbtree_commit,
767 .gc_init = nft_rbtree_gc_init,
768 .lookup = nft_rbtree_lookup,
769 .walk = nft_rbtree_walk,
770 .get = nft_rbtree_get,