1 files changed, 311 insertions, 67 deletions

diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index ee7c29e0a9d7..2b5f65a424b7 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -14,6 +14,9 @@
 #include <linux/netfilter.h>
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables_core.h>
+#include <net/netns/generic.h>
+
+extern unsigned int nf_tables_net_id;
 
 struct nft_rbtree {
 	struct rb_root		root;
@@ -38,10 +41,18 @@ static bool nft_rbtree_interval_start(const struct nft_rbtree_elem *rbe)
 	return !nft_rbtree_interval_end(rbe);
 }
 
-static bool nft_rbtree_equal(const struct nft_set *set, const void *this,
-			     const struct nft_rbtree_elem *interval)
+static int nft_rbtree_cmp(const struct nft_set *set,
+			  const struct nft_rbtree_elem *e1,
+			  const struct nft_rbtree_elem *e2)
+{
+	return memcmp(nft_set_ext_key(&e1->ext), nft_set_ext_key(&e2->ext),
+		      set->klen);
+}
+
+static bool nft_rbtree_elem_expired(const struct nft_rbtree_elem *rbe)
 {
-	return memcmp(this, nft_set_ext_key(&interval->ext), set->klen) == 0;
+	return nft_set_elem_expired(&rbe->ext) ||
+	       nft_set_elem_is_dead(&rbe->ext);
 }
 
 static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
@@ -52,7 +63,6 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
 	const struct nft_rbtree_elem *rbe, *interval = NULL;
 	u8 genmask = nft_genmask_cur(net);
 	const struct rb_node *parent;
-	const void *this;
 	int d;
 
 	parent = rcu_dereference_raw(priv->root.rb_node);
@@ -62,12 +72,11 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
 
 		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 
-		this = nft_set_ext_key(&rbe->ext);
-		d = memcmp(this, key, set->klen);
+		d = memcmp(nft_set_ext_key(&rbe->ext), key, set->klen);
 		if (d < 0) {
 			parent = rcu_dereference_raw(parent->rb_left);
 			if (interval &&
-			    nft_rbtree_equal(set, this, interval) &&
+			    !nft_rbtree_cmp(set, rbe, interval) &&
 			    nft_rbtree_interval_end(rbe) &&
 			    nft_rbtree_interval_start(interval))
 				continue;
@@ -80,7 +89,7 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
 				continue;
 			}
 
-			if (nft_set_elem_expired(&rbe->ext))
+			if (nft_rbtree_elem_expired(rbe))
 				return false;
 
 			if (nft_rbtree_interval_end(rbe)) {
@@ -98,7 +107,7 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
 
 	if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 	    nft_set_elem_active(&interval->ext, genmask) &&
-	    !nft_set_elem_expired(&interval->ext) &&
+	    !nft_rbtree_elem_expired(interval) &&
 	    nft_rbtree_interval_start(interval)) {
 		*ext = &interval->ext;
 		return true;
@@ -214,43 +223,257 @@ static void *nft_rbtree_get(const struct net *net, const struct nft_set *set,
 	return rbe;
 }
 
+static void nft_rbtree_gc_remove(struct net *net, struct nft_set *set,
+				 struct nft_rbtree *priv,
+				 struct nft_rbtree_elem *rbe)
+{
+	struct nft_set_elem elem = {
+		.priv	= rbe,
+	};
+
+	nft_setelem_data_deactivate(net, set, &elem);
+	rb_erase(&rbe->node, &priv->root);
+}
+
+static int nft_rbtree_gc_elem(const struct nft_set *__set,
+			      struct nft_rbtree *priv,
+			      struct nft_rbtree_elem *rbe)
+{
+	struct nft_set *set = (struct nft_set *)__set;
+	struct rb_node *prev = rb_prev(&rbe->node);
+	struct net *net = read_pnet(&set->net);
+	struct nft_rbtree_elem *rbe_prev;
+	struct nft_trans_gc *gc;
+
+	gc = nft_trans_gc_alloc(set, 0, GFP_ATOMIC);
+	if (!gc)
+		return -ENOMEM;
+
+	/* search for end interval coming before this element.
+	 * end intervals don't carry a timeout extension, they
+	 * are coupled with the interval start element.
+	 */
+	while (prev) {
+		rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
+		if (nft_rbtree_interval_end(rbe_prev) &&
+		    nft_set_elem_active(&rbe_prev->ext, NFT_GENMASK_ANY))
+			break;
+
+		prev = rb_prev(prev);
+	}
+
+	if (prev) {
+		rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
+		nft_rbtree_gc_remove(net, set, priv, rbe_prev);
+
+		/* There is always room in this trans gc for this element,
+		 * memory allocation never actually happens, hence, the warning
+		 * splat in such case. No need to set NFT_SET_ELEM_DEAD_BIT,
+		 * this is synchronous gc which never fails.
+		 */
+		gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+		if (WARN_ON_ONCE(!gc))
+			return -ENOMEM;
+
+		nft_trans_gc_elem_add(gc, rbe_prev);
+	}
+
+	nft_rbtree_gc_remove(net, set, priv, rbe);
+	gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+	if (WARN_ON_ONCE(!gc))
+		return -ENOMEM;
+
+	nft_trans_gc_elem_add(gc, rbe);
+
+	nft_trans_gc_queue_sync_done(gc);
+
+	return 0;
+}
+
+static bool nft_rbtree_update_first(const struct nft_set *set,
+				    struct nft_rbtree_elem *rbe,
+				    struct rb_node *first)
+{
+	struct nft_rbtree_elem *first_elem;
+
+	first_elem = rb_entry(first, struct nft_rbtree_elem, node);
+	/* this element is closest to where the new element is to be inserted:
+	 * update the first element for the node list path.
+	 */
+	if (nft_rbtree_cmp(set, rbe, first_elem) < 0)
+		return true;
+
+	return false;
+}
+
 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 			       struct nft_rbtree_elem *new,
 			       struct nft_set_ext **ext)
 {
+	struct nft_rbtree_elem *rbe, *rbe_le = NULL, *rbe_ge = NULL;
+	struct rb_node *node, *next, *parent, **p, *first = NULL;
 	struct nft_rbtree *priv = nft_set_priv(set);
+	u8 cur_genmask = nft_genmask_cur(net);
 	u8 genmask = nft_genmask_next(net);
-	struct nft_rbtree_elem *rbe;
-	struct rb_node *parent, **p;
-	int d;
+	int d, err;
 
+	/* Descend the tree to search for an existing element greater than the
+	 * key value to insert that is greater than the new element. This is the
+	 * first element to walk the ordered elements to find possible overlap.
+	 */
 	parent = NULL;
 	p = &priv->root.rb_node;
 	while (*p != NULL) {
 		parent = *p;
 		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
-		d = memcmp(nft_set_ext_key(&rbe->ext),
-			   nft_set_ext_key(&new->ext),
-			   set->klen);
-		if (d < 0)
+		d = nft_rbtree_cmp(set, rbe, new);
+
+		if (d < 0) {
 			p = &parent->rb_left;
-		else if (d > 0)
+		} else if (d > 0) {
+			if (!first ||
+			    nft_rbtree_update_first(set, rbe, first))
+				first = &rbe->node;
+
 			p = &parent->rb_right;
-		else {
-			if (nft_rbtree_interval_end(rbe) &&
-			    nft_rbtree_interval_start(new)) {
+		} else {
+			if (nft_rbtree_interval_end(rbe))
 				p = &parent->rb_left;
-			} else if (nft_rbtree_interval_start(rbe) &&
-				   nft_rbtree_interval_end(new)) {
+			else
 				p = &parent->rb_right;
-			} else if (nft_set_elem_active(&rbe->ext, genmask)) {
-				*ext = &rbe->ext;
-				return -EEXIST;
-			} else {
-				p = &parent->rb_left;
+		}
+	}
+
+	if (!first)
+		first = rb_first(&priv->root);
+
+	/* Detect overlap by going through the list of valid tree nodes.
+	 * Values stored in the tree are in reversed order, starting from
+	 * highest to lowest value.
+	 */
+	for (node = first; node != NULL; node = next) {
+		next = rb_next(node);
+
+		rbe = rb_entry(node, struct nft_rbtree_elem, node);
+
+		if (!nft_set_elem_active(&rbe->ext, genmask))
+			continue;
+
+		/* perform garbage collection to avoid bogus overlap reports
+		 * but skip new elements in this transaction.
+		 */
+		if (nft_set_elem_expired(&rbe->ext) &&
+		    nft_set_elem_active(&rbe->ext, cur_genmask)) {
+			err = nft_rbtree_gc_elem(set, priv, rbe);
+			if (err < 0)
+				return err;
+
+			continue;
+		}
+
+		d = nft_rbtree_cmp(set, rbe, new);
+		if (d == 0) {
+			/* Matching end element: no need to look for an
+			 * overlapping greater or equal element.
+			 */
+			if (nft_rbtree_interval_end(rbe)) {
+				rbe_le = rbe;
+				break;
+			}
+
+			/* first element that is greater or equal to key value. */
+			if (!rbe_ge) {
+				rbe_ge = rbe;
+				continue;
+			}
+
+			/* this is a closer more or equal element, update it. */
+			if (nft_rbtree_cmp(set, rbe_ge, new) != 0) {
+				rbe_ge = rbe;
+				continue;
+			}
+
+			/* element is equal to key value, make sure flags are
+			 * the same, an existing more or equal start element
+			 * must not be replaced by more or equal end element.
+			 */
+			if ((nft_rbtree_interval_start(new) &&
+			     nft_rbtree_interval_start(rbe_ge)) ||
+			    (nft_rbtree_interval_end(new) &&
+			     nft_rbtree_interval_end(rbe_ge))) {
+				rbe_ge = rbe;
+				continue;
 			}
+		} else if (d > 0) {
+			/* annotate element greater than the new element. */
+			rbe_ge = rbe;
+			continue;
+		} else if (d < 0) {
+			/* annotate element less than the new element. */
+			rbe_le = rbe;
+			break;
 		}
 	}
+
+	/* - new start element matching existing start element: full overlap
+	 *   reported as -EEXIST, cleared by caller if NLM_F_EXCL is not given.
+	 */
+	if (rbe_ge && !nft_rbtree_cmp(set, new, rbe_ge) &&
+	    nft_rbtree_interval_start(rbe_ge) == nft_rbtree_interval_start(new)) {
+		*ext = &rbe_ge->ext;
+		return -EEXIST;
+	}
+
+	/* - new end element matching existing end element: full overlap
+	 *   reported as -EEXIST, cleared by caller if NLM_F_EXCL is not given.
+	 */
+	if (rbe_le && !nft_rbtree_cmp(set, new, rbe_le) &&
+	    nft_rbtree_interval_end(rbe_le) == nft_rbtree_interval_end(new)) {
+		*ext = &rbe_le->ext;
+		return -EEXIST;
+	}
+
+	/* - new start element with existing closest, less or equal key value
+	 *   being a start element: partial overlap, reported as -ENOTEMPTY.
+	 *   Anonymous sets allow for two consecutive start element since they
+	 *   are constant, skip them to avoid bogus overlap reports.
+	 */
+	if (!nft_set_is_anonymous(set) && rbe_le &&
+	    nft_rbtree_interval_start(rbe_le) && nft_rbtree_interval_start(new))
+		return -ENOTEMPTY;
+
+	/* - new end element with existing closest, less or equal key value
+	 *   being a end element: partial overlap, reported as -ENOTEMPTY.
+	 */
+	if (rbe_le &&
+	    nft_rbtree_interval_end(rbe_le) && nft_rbtree_interval_end(new))
+		return -ENOTEMPTY;
+
+	/* - new end element with existing closest, greater or equal key value
+	 *   being an end element: partial overlap, reported as -ENOTEMPTY
+	 */
+	if (rbe_ge &&
+	    nft_rbtree_interval_end(rbe_ge) && nft_rbtree_interval_end(new))
+		return -ENOTEMPTY;
+
+	/* Accepted element: pick insertion point depending on key value */
+	parent = NULL;
+	p = &priv->root.rb_node;
+	while (*p != NULL) {
+		parent = *p;
+		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
+		d = nft_rbtree_cmp(set, rbe, new);
+
+		if (d < 0)
+			p = &parent->rb_left;
+		else if (d > 0)
+			p = &parent->rb_right;
+		else if (nft_rbtree_interval_end(rbe))
+			p = &parent->rb_left;
+		else
+			p = &parent->rb_right;
+	}
+
 	rb_link_node_rcu(&new->node, parent, p);
 	rb_insert_color(&new->node, &priv->root);
 	return 0;
@@ -294,7 +517,6 @@ static void nft_rbtree_activate(const struct net *net,
 	struct nft_rbtree_elem *rbe = elem->priv;
 
 	nft_set_elem_change_active(net, set, &rbe->ext);
-	nft_set_elem_clear_busy(&rbe->ext);
 }
 
 static bool nft_rbtree_flush(const struct net *net,
@@ -302,12 +524,9 @@ static bool nft_rbtree_flush(const struct net *net,
 {
 	struct nft_rbtree_elem *rbe = priv;
 
-	if (!nft_set_elem_mark_busy(&rbe->ext) ||
-	    !nft_is_active(net, &rbe->ext)) {
-		nft_set_elem_change_active(net, set, &rbe->ext);
-		return true;
-	}
-	return false;
+	nft_set_elem_change_active(net, set, &rbe->ext);
+
+	return true;
 }
 
 static void *nft_rbtree_deactivate(const struct net *net,
@@ -338,6 +557,8 @@ static void *nft_rbtree_deactivate(const struct net *net,
 				   nft_rbtree_interval_end(this)) {
 				parent = parent->rb_right;
 				continue;
+			} else if (nft_set_elem_expired(&rbe->ext)) {
+				break;
 			} else if (!nft_set_elem_active(&rbe->ext, genmask)) {
 				parent = parent->rb_left;
 				continue;
@@ -364,8 +585,6 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx,
 
 		if (iter->count < iter->skip)
 			goto cont;
-		if (nft_set_elem_expired(&rbe->ext))
-			goto cont;
 		if (!nft_set_elem_active(&rbe->ext, iter->genmask))
 			goto cont;
 
@@ -384,58 +603,82 @@ cont:
 
 static void nft_rbtree_gc(struct work_struct *work)
 {
-	struct nft_rbtree_elem *rbe, *rbe_end = NULL, *rbe_prev = NULL;
-	struct nft_set_gc_batch *gcb = NULL;
+	struct nft_rbtree_elem *rbe, *rbe_end = NULL;
+	struct nftables_pernet *nft_net;
 	struct nft_rbtree *priv;
+	struct nft_trans_gc *gc;
 	struct rb_node *node;
 	struct nft_set *set;
+	unsigned int gc_seq;
+	struct net *net;
 
 	priv = container_of(work, struct nft_rbtree, gc_work.work);
 	set  = nft_set_container_of(priv);
+	net  = read_pnet(&set->net);
+	nft_net = net_generic(net, nf_tables_net_id);
+	gc_seq  = READ_ONCE(nft_net->gc_seq);
 
-	write_lock_bh(&priv->lock);
-	write_seqcount_begin(&priv->count);
+	if (nft_set_gc_is_pending(set))
+		goto done;
+
+	gc = nft_trans_gc_alloc(set, gc_seq, GFP_KERNEL);
+	if (!gc)
+		goto done;
+
+	read_lock_bh(&priv->lock);
 	for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
+
+		/* Ruleset has been updated, try later. */
+		if (READ_ONCE(nft_net->gc_seq) != gc_seq) {
+			nft_trans_gc_destroy(gc);
+			gc = NULL;
+			goto try_later;
+		}
+
 		rbe = rb_entry(node, struct nft_rbtree_elem, node);
 
+		if (nft_set_elem_is_dead(&rbe->ext))
+			goto dead_elem;
+
+		/* elements are reversed in the rbtree for historical reasons,
+		 * from highest to lowest value, that is why end element is
+		 * always visited before the start element.
+		 */
 		if (nft_rbtree_interval_end(rbe)) {
 			rbe_end = rbe;
 			continue;
 		}
+
 		if (!nft_set_elem_expired(&rbe->ext))
 			continue;
-		if (nft_set_elem_mark_busy(&rbe->ext))
+
+		nft_set_elem_dead(&rbe->ext);
+
+		if (!rbe_end)
 			continue;
 
-		if (rbe_prev) {
-			rb_erase(&rbe_prev->node, &priv->root);
-			rbe_prev = NULL;
-		}
-		gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
-		if (!gcb)
-			break;
+		nft_set_elem_dead(&rbe_end->ext);
 
-		atomic_dec(&set->nelems);
-		nft_set_gc_batch_add(gcb, rbe);
-		rbe_prev = rbe;
+		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+		if (!gc)
+			goto try_later;
 
-		if (rbe_end) {
-			atomic_dec(&set->nelems);
-			nft_set_gc_batch_add(gcb, rbe_end);
-			rb_erase(&rbe_end->node, &priv->root);
-			rbe_end = NULL;
-		}
-		node = rb_next(node);
-		if (!node)
-			break;
+		nft_trans_gc_elem_add(gc, rbe_end);
+		rbe_end = NULL;
+dead_elem:
+		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+		if (!gc)
+			goto try_later;
+
+		nft_trans_gc_elem_add(gc, rbe);
 	}
-	if (rbe_prev)
-		rb_erase(&rbe_prev->node, &priv->root);
-	write_seqcount_end(&priv->count);
-	write_unlock_bh(&priv->lock);
 
-	nft_set_gc_batch_complete(gcb);
+try_later:
+	read_unlock_bh(&priv->lock);
 
+	if (gc)
+		nft_trans_gc_queue_async_done(gc);
+done:
 	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
 			   nft_set_gc_interval(set));
 }
@@ -464,7 +707,8 @@ static int nft_rbtree_init(const struct nft_set *set,
 	return 0;
 }
 
-static void nft_rbtree_destroy(const struct nft_set *set)
+static void nft_rbtree_destroy(const struct nft_ctx *ctx,
+			       const struct nft_set *set)
 {
 	struct nft_rbtree *priv = nft_set_priv(set);
 	struct nft_rbtree_elem *rbe;
@@ -475,7 +719,7 @@ static void nft_rbtree_destroy(const struct nft_set *set)
 	while ((node = priv->root.rb_node) != NULL) {
 		rb_erase(node, &priv->root);
 		rbe = rb_entry(node, struct nft_rbtree_elem, node);
-		nft_set_elem_destroy(set, rbe, true);
+		nf_tables_set_elem_destroy(ctx, set, rbe);
 	}
 }