netfilter: nft_set_rbtree: add timeout support

Add garbage collection logic to expire elements stored in the rb-tree
representation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2018-05-16 22:58:34 +02:00
parent 57a4c9c5c7
commit 8d8540c4f5
1 changed files with 72 additions and 3 deletions

View File

@ -22,6 +22,7 @@ struct nft_rbtree {
struct rb_root root;
rwlock_t lock;
seqcount_t count;
struct delayed_work gc_work;
};
struct nft_rbtree_elem {
@ -265,6 +266,7 @@ 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,
@ -272,8 +274,12 @@ static bool nft_rbtree_flush(const struct net *net,
{
struct nft_rbtree_elem *rbe = priv;
nft_set_elem_change_active(net, set, &rbe->ext);
return true;
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;
}
static void *nft_rbtree_deactivate(const struct net *net,
@ -347,6 +353,62 @@ cont:
read_unlock_bh(&priv->lock);
}
static void nft_rbtree_gc(struct work_struct *work)
{
struct nft_set_gc_batch *gcb = NULL;
struct rb_node *node, *prev = NULL;
struct nft_rbtree_elem *rbe;
struct nft_rbtree *priv;
struct nft_set *set;
int i;
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)) {
prev = node;
continue;
}
if (!nft_set_elem_expired(&rbe->ext))
continue;
if (nft_set_elem_mark_busy(&rbe->ext))
continue;
gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
if (!gcb)
goto out;
atomic_dec(&set->nelems);
nft_set_gc_batch_add(gcb, rbe);
if (prev) {
rbe = rb_entry(prev, struct nft_rbtree_elem, node);
atomic_dec(&set->nelems);
nft_set_gc_batch_add(gcb, rbe);
}
node = rb_next(node);
}
out:
if (gcb) {
for (i = 0; i < gcb->head.cnt; i++) {
rbe = gcb->elems[i];
rb_erase(&rbe->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 unsigned int nft_rbtree_privsize(const struct nlattr * const nla[],
const struct nft_set_desc *desc)
{
@ -362,6 +424,12 @@ static int nft_rbtree_init(const struct nft_set *set,
rwlock_init(&priv->lock);
seqcount_init(&priv->count);
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;
}
@ -371,6 +439,7 @@ static void nft_rbtree_destroy(const struct nft_set *set)
struct nft_rbtree_elem *rbe;
struct rb_node *node;
cancel_delayed_work_sync(&priv->gc_work);
while ((node = priv->root.rb_node) != NULL) {
rb_erase(node, &priv->root);
rbe = rb_entry(node, struct nft_rbtree_elem, node);
@ -395,7 +464,7 @@ static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
static struct nft_set_type nft_rbtree_type __read_mostly = {
.owner = THIS_MODULE,
.features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT,
.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),