diff options
Diffstat (limited to 'net/netfilter/nft_set_rbtree.c')
-rw-r--r-- | net/netfilter/nft_set_rbtree.c | 378 |
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); } } |