// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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*
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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/rbtree.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables_core.h>
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struct nft_rbtree {
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struct rb_root root;
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rwlock_t lock;
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seqcount_rwlock_t count;
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struct delayed_work gc_work;
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};
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struct nft_rbtree_elem {
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struct rb_node node;
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struct nft_set_ext ext;
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};
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static bool nft_rbtree_interval_end(const struct nft_rbtree_elem *rbe)
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{
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return nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) &&
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(*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END);
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}
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static bool nft_rbtree_interval_start(const struct nft_rbtree_elem *rbe)
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{
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return !nft_rbtree_interval_end(rbe);
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}
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static bool nft_rbtree_equal(const struct nft_set *set, const void *this,
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const struct nft_rbtree_elem *interval)
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{
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return memcmp(this, nft_set_ext_key(&interval->ext), set->klen) == 0;
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}
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static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
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const u32 *key, const struct nft_set_ext **ext,
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unsigned int seq)
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{
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struct nft_rbtree *priv = nft_set_priv(set);
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const struct nft_rbtree_elem *rbe, *interval = NULL;
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u8 genmask = nft_genmask_cur(net);
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const struct rb_node *parent;
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const void *this;
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int d;
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parent = rcu_dereference_raw(priv->root.rb_node);
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while (parent != NULL) {
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if (read_seqcount_retry(&priv->count, seq))
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return false;
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rbe = rb_entry(parent, struct nft_rbtree_elem, node);
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this = nft_set_ext_key(&rbe->ext);
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d = memcmp(this, key, set->klen);
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if (d < 0) {
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parent = rcu_dereference_raw(parent->rb_left);
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if (interval &&
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nft_rbtree_equal(set, this, interval) &&
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nft_rbtree_interval_end(rbe) &&
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nft_rbtree_interval_start(interval))
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continue;
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interval = rbe;
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} else if (d > 0)
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parent = rcu_dereference_raw(parent->rb_right);
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else {
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if (!nft_set_elem_active(&rbe->ext, genmask)) {
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parent = rcu_dereference_raw(parent->rb_left);
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continue;
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}
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if (nft_set_elem_expired(&rbe->ext))
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return false;
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if (nft_rbtree_interval_end(rbe)) {
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if (nft_set_is_anonymous(set))
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return false;
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parent = rcu_dereference_raw(parent->rb_left);
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interval = NULL;
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continue;
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}
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*ext = &rbe->ext;
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return true;
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}
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}
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if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
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nft_set_elem_active(&interval->ext, genmask) &&
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!nft_set_elem_expired(&interval->ext) &&
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nft_rbtree_interval_start(interval)) {
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*ext = &interval->ext;
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return true;
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}
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return false;
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}
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static bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
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const u32 *key, const struct nft_set_ext **ext)
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{
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struct nft_rbtree *priv = nft_set_priv(set);
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unsigned int seq = read_seqcount_begin(&priv->count);
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bool ret;
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ret = __nft_rbtree_lookup(net, set, key, ext, seq);
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if (ret || !read_seqcount_retry(&priv->count, seq))
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return ret;
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read_lock_bh(&priv->lock);
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seq = read_seqcount_begin(&priv->count);
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ret = __nft_rbtree_lookup(net, set, key, ext, seq);
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read_unlock_bh(&priv->lock);
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return ret;
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}
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static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
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const u32 *key, struct nft_rbtree_elem **elem,
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unsigned int seq, unsigned int flags, u8 genmask)
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{
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struct nft_rbtree_elem *rbe, *interval = NULL;
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struct nft_rbtree *priv = nft_set_priv(set);
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const struct rb_node *parent;
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const void *this;
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int d;
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parent = rcu_dereference_raw(priv->root.rb_node);
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while (parent != NULL) {
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if (read_seqcount_retry(&priv->count, seq))
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return false;
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rbe = rb_entry(parent, struct nft_rbtree_elem, node);
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this = nft_set_ext_key(&rbe->ext);
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d = memcmp(this, key, set->klen);
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if (d < 0) {
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parent = rcu_dereference_raw(parent->rb_left);
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if (!(flags & NFT_SET_ELEM_INTERVAL_END))
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interval = rbe;
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} else if (d > 0) {
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parent = rcu_dereference_raw(parent->rb_right);
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if (flags & NFT_SET_ELEM_INTERVAL_END)
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interval = rbe;
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} else {
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if (!nft_set_elem_active(&rbe->ext, genmask)) {
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parent = rcu_dereference_raw(parent->rb_left);
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continue;
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}
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if (nft_set_elem_expired(&rbe->ext))
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return false;
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if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) ||
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(*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) ==
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(flags & NFT_SET_ELEM_INTERVAL_END)) {
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*elem = rbe;
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return true;
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}
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if (nft_rbtree_interval_end(rbe))
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interval = NULL;
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parent = rcu_dereference_raw(parent->rb_left);
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}
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}
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if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
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nft_set_elem_active(&interval->ext, genmask) &&
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!nft_set_elem_expired(&interval->ext) &&
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((!nft_rbtree_interval_end(interval) &&
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!(flags & NFT_SET_ELEM_INTERVAL_END)) ||
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(nft_rbtree_interval_end(interval) &&
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(flags & NFT_SET_ELEM_INTERVAL_END)))) {
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*elem = interval;
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return true;
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}
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return false;
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}
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static void *nft_rbtree_get(const struct net *net, const struct nft_set *set,
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const struct nft_set_elem *elem, unsigned int flags)
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{
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struct nft_rbtree *priv = nft_set_priv(set);
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unsigned int seq = read_seqcount_begin(&priv->count);
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struct nft_rbtree_elem *rbe = ERR_PTR(-ENOENT);
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const u32 *key = (const u32 *)&elem->key.val;
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u8 genmask = nft_genmask_cur(net);
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bool ret;
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ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
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if (ret || !read_seqcount_retry(&priv->count, seq))
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return rbe;
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read_lock_bh(&priv->lock);
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seq = read_seqcount_begin(&priv->count);
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ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask);
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if (!ret)
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rbe = ERR_PTR(-ENOENT);
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read_unlock_bh(&priv->lock);
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return rbe;
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}
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static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
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struct nft_rbtree_elem *new,
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struct nft_set_ext **ext)
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{
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bool overlap = false, dup_end_left = false, dup_end_right = false;
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struct nft_rbtree *priv = nft_set_priv(set);
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u8 genmask = nft_genmask_next(net);
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struct nft_rbtree_elem *rbe;
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struct rb_node *parent, **p;
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int d;
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/* Detect overlaps as we descend the tree. Set the flag in these cases:
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*
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* a1. _ _ __>| ?_ _ __| (insert end before existing end)
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* a2. _ _ ___| ?_ _ _>| (insert end after existing end)
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* a3. _ _ ___? >|_ _ __| (insert start before existing end)
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*
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* and clear it later on, as we eventually reach the points indicated by
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* '?' above, in the cases described below. We'll always meet these
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* later, locally, due to tree ordering, and overlaps for the intervals
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* that are the closest together are always evaluated last.
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*
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* b1. _ _ __>| !_ _ __| (insert end before existing start)
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* b2. _ _ ___| !_ _ _>| (insert end after existing start)
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* b3. _ _ ___! >|_ _ __| (insert start after existing end, as a leaf)
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* '--' no nodes falling in this range
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* b4. >|_ _ ! (insert start before existing start)
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*
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* Case a3. resolves to b3.:
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* - if the inserted start element is the leftmost, because the '0'
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* element in the tree serves as end element
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* - otherwise, if an existing end is found immediately to the left. If
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* there are existing nodes in between, we need to further descend the
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* tree before we can conclude the new start isn't causing an overlap
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*
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* or to b4., which, preceded by a3., means we already traversed one or
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* more existing intervals entirely, from the right.
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*
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* For a new, rightmost pair of elements, we'll hit cases b3. and b2.,
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* in that order.
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*
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* The flag is also cleared in two special cases:
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*
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* b5. |__ _ _!|<_ _ _ (insert start right before existing end)
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* b6. |__ _ >|!__ _ _ (insert end right after existing start)
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*
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* which always happen as last step and imply that no further
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* overlapping is possible.
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*
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* Another special case comes from the fact that start elements matching
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* an already existing start element are allowed: insertion is not
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* performed but we return -EEXIST in that case, and the error will be
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* cleared by the caller if NLM_F_EXCL is not present in the request.
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* This way, request for insertion of an exact overlap isn't reported as
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* error to userspace if not desired.
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*
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* However, if the existing start matches a pre-existing start, but the
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* end element doesn't match the corresponding pre-existing end element,
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* we need to report a partial overlap. This is a local condition that
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* can be noticed without need for a tracking flag, by checking for a
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* local duplicated end for a corresponding start, from left and right,
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* separately.
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*/
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parent = NULL;
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p = &priv->root.rb_node;
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while (*p != NULL) {
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parent = *p;
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rbe = rb_entry(parent, struct nft_rbtree_elem, node);
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d = memcmp(nft_set_ext_key(&rbe->ext),
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nft_set_ext_key(&new->ext),
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set->klen);
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if (d < 0) {
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p = &parent->rb_left;
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if (nft_rbtree_interval_start(new)) {
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if (nft_rbtree_interval_end(rbe) &&
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nft_set_elem_active(&rbe->ext, genmask) &&
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!nft_set_elem_expired(&rbe->ext) && !*p)
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overlap = false;
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} else {
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if (dup_end_left && !*p)
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return -ENOTEMPTY;
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overlap = nft_rbtree_interval_end(rbe) &&
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nft_set_elem_active(&rbe->ext,
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genmask) &&
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!nft_set_elem_expired(&rbe->ext);
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if (overlap) {
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dup_end_right = true;
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continue;
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}
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}
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} else if (d > 0) {
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p = &parent->rb_right;
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if (nft_rbtree_interval_end(new)) {
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if (dup_end_right && !*p)
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return -ENOTEMPTY;
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overlap = nft_rbtree_interval_end(rbe) &&
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nft_set_elem_active(&rbe->ext,
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genmask) &&
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!nft_set_elem_expired(&rbe->ext);
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if (overlap) {
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dup_end_left = true;
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continue;
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}
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} else if (nft_set_elem_active(&rbe->ext, genmask) &&
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!nft_set_elem_expired(&rbe->ext)) {
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overlap = nft_rbtree_interval_end(rbe);
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}
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} else {
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if (nft_rbtree_interval_end(rbe) &&
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nft_rbtree_interval_start(new)) {
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p = &parent->rb_left;
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if (nft_set_elem_active(&rbe->ext, genmask) &&
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!nft_set_elem_expired(&rbe->ext))
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overlap = false;
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} else if (nft_rbtree_interval_start(rbe) &&
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nft_rbtree_interval_end(new)) {
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p = &parent->rb_right;
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if (nft_set_elem_active(&rbe->ext, genmask) &&
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!nft_set_elem_expired(&rbe->ext))
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overlap = false;
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} else if (nft_set_elem_active(&rbe->ext, genmask) &&
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!nft_set_elem_expired(&rbe->ext)) {
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*ext = &rbe->ext;
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return -EEXIST;
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} else {
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overlap = false;
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if (nft_rbtree_interval_end(rbe))
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p = &parent->rb_left;
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else
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p = &parent->rb_right;
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}
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}
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dup_end_left = dup_end_right = false;
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}
|
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if (overlap)
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return -ENOTEMPTY;
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rb_link_node_rcu(&new->node, parent, p);
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rb_insert_color(&new->node, &priv->root);
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return 0;
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}
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static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
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const struct nft_set_elem *elem,
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struct nft_set_ext **ext)
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{
|
struct nft_rbtree *priv = nft_set_priv(set);
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struct nft_rbtree_elem *rbe = elem->priv;
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int err;
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write_lock_bh(&priv->lock);
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write_seqcount_begin(&priv->count);
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err = __nft_rbtree_insert(net, set, rbe, ext);
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write_seqcount_end(&priv->count);
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write_unlock_bh(&priv->lock);
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return err;
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}
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static void nft_rbtree_remove(const struct net *net,
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const struct nft_set *set,
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const struct nft_set_elem *elem)
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{
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struct nft_rbtree *priv = nft_set_priv(set);
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struct nft_rbtree_elem *rbe = elem->priv;
|
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write_lock_bh(&priv->lock);
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write_seqcount_begin(&priv->count);
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rb_erase(&rbe->node, &priv->root);
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write_seqcount_end(&priv->count);
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write_unlock_bh(&priv->lock);
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}
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static void nft_rbtree_activate(const struct net *net,
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const struct nft_set *set,
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const struct nft_set_elem *elem)
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{
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struct nft_rbtree_elem *rbe = elem->priv;
|
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nft_set_elem_change_active(net, set, &rbe->ext);
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nft_set_elem_clear_busy(&rbe->ext);
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}
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static bool nft_rbtree_flush(const struct net *net,
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const struct nft_set *set, void *priv)
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{
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struct nft_rbtree_elem *rbe = priv;
|
|
if (!nft_set_elem_mark_busy(&rbe->ext) ||
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!nft_is_active(net, &rbe->ext)) {
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nft_set_elem_change_active(net, set, &rbe->ext);
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return true;
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}
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return false;
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}
|
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static void *nft_rbtree_deactivate(const struct net *net,
|
const struct nft_set *set,
|
const struct nft_set_elem *elem)
|
{
|
const struct nft_rbtree *priv = nft_set_priv(set);
|
const struct rb_node *parent = priv->root.rb_node;
|
struct nft_rbtree_elem *rbe, *this = elem->priv;
|
u8 genmask = nft_genmask_next(net);
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int d;
|
|
while (parent != NULL) {
|
rbe = rb_entry(parent, struct nft_rbtree_elem, node);
|
|
d = memcmp(nft_set_ext_key(&rbe->ext), &elem->key.val,
|
set->klen);
|
if (d < 0)
|
parent = parent->rb_left;
|
else if (d > 0)
|
parent = parent->rb_right;
|
else {
|
if (nft_rbtree_interval_end(rbe) &&
|
nft_rbtree_interval_start(this)) {
|
parent = parent->rb_left;
|
continue;
|
} else if (nft_rbtree_interval_start(rbe) &&
|
nft_rbtree_interval_end(this)) {
|
parent = parent->rb_right;
|
continue;
|
} else if (!nft_set_elem_active(&rbe->ext, genmask)) {
|
parent = parent->rb_left;
|
continue;
|
}
|
nft_rbtree_flush(net, set, rbe);
|
return rbe;
|
}
|
}
|
return NULL;
|
}
|
|
static void nft_rbtree_walk(const struct nft_ctx *ctx,
|
struct nft_set *set,
|
struct nft_set_iter *iter)
|
{
|
struct nft_rbtree *priv = nft_set_priv(set);
|
struct nft_rbtree_elem *rbe;
|
struct nft_set_elem elem;
|
struct rb_node *node;
|
|
read_lock_bh(&priv->lock);
|
for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
|
rbe = rb_entry(node, struct nft_rbtree_elem, node);
|
|
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;
|
|
elem.priv = rbe;
|
|
iter->err = iter->fn(ctx, set, iter, &elem);
|
if (iter->err < 0) {
|
read_unlock_bh(&priv->lock);
|
return;
|
}
|
cont:
|
iter->count++;
|
}
|
read_unlock_bh(&priv->lock);
|
}
|
|
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 *priv;
|
struct rb_node *node;
|
struct nft_set *set;
|
|
priv = container_of(work, struct nft_rbtree, gc_work.work);
|
set = nft_set_container_of(priv);
|
|
write_lock_bh(&priv->lock);
|
write_seqcount_begin(&priv->count);
|
for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
|
rbe = rb_entry(node, struct nft_rbtree_elem, node);
|
|
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))
|
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;
|
|
atomic_dec(&set->nelems);
|
nft_set_gc_batch_add(gcb, rbe);
|
rbe_prev = rbe;
|
|
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;
|
}
|
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);
|
|
queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
|
nft_set_gc_interval(set));
|
}
|
|
static u64 nft_rbtree_privsize(const struct nlattr * const nla[],
|
const struct nft_set_desc *desc)
|
{
|
return sizeof(struct nft_rbtree);
|
}
|
|
static int nft_rbtree_init(const struct nft_set *set,
|
const struct nft_set_desc *desc,
|
const struct nlattr * const nla[])
|
{
|
struct nft_rbtree *priv = nft_set_priv(set);
|
|
rwlock_init(&priv->lock);
|
seqcount_rwlock_init(&priv->count, &priv->lock);
|
priv->root = RB_ROOT;
|
|
INIT_DEFERRABLE_WORK(&priv->gc_work, nft_rbtree_gc);
|
if (set->flags & NFT_SET_TIMEOUT)
|
queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
|
nft_set_gc_interval(set));
|
|
return 0;
|
}
|
|
static void nft_rbtree_destroy(const struct nft_set *set)
|
{
|
struct nft_rbtree *priv = nft_set_priv(set);
|
struct nft_rbtree_elem *rbe;
|
struct rb_node *node;
|
|
cancel_delayed_work_sync(&priv->gc_work);
|
rcu_barrier();
|
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);
|
}
|
}
|
|
static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
|
struct nft_set_estimate *est)
|
{
|
if (desc->field_count > 1)
|
return false;
|
|
if (desc->size)
|
est->size = sizeof(struct nft_rbtree) +
|
desc->size * sizeof(struct nft_rbtree_elem);
|
else
|
est->size = ~0;
|
|
est->lookup = NFT_SET_CLASS_O_LOG_N;
|
est->space = NFT_SET_CLASS_O_N;
|
|
return true;
|
}
|
|
const struct nft_set_type nft_set_rbtree_type = {
|
.features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
|
.ops = {
|
.privsize = nft_rbtree_privsize,
|
.elemsize = offsetof(struct nft_rbtree_elem, ext),
|
.estimate = nft_rbtree_estimate,
|
.init = nft_rbtree_init,
|
.destroy = nft_rbtree_destroy,
|
.insert = nft_rbtree_insert,
|
.remove = nft_rbtree_remove,
|
.deactivate = nft_rbtree_deactivate,
|
.flush = nft_rbtree_flush,
|
.activate = nft_rbtree_activate,
|
.lookup = nft_rbtree_lookup,
|
.walk = nft_rbtree_walk,
|
.get = nft_rbtree_get,
|
},
|
};
|
