From: Patrick McHardy <kaber@xxxxxxxxx>
Add support for element timeouts to nft_hash. The lookup and walking
functions are changed to ignore timed out elements, a periodic garbage
collection task cleans out expired entries.
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_tables.h | 5 +++
net/netfilter/nft_hash.c | 79 +++++++++++++++++++++++++++++++++++--
2 files changed, 80 insertions(+), 4 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 1ea13fc..a785699 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -294,6 +294,11 @@ static inline void *nft_set_priv(const struct nft_set *set)
return (void *)set->data;
}
+static inline struct nft_set *nft_set_container_of(const void *priv)
+{
+ return (void *)priv - offsetof(struct nft_set, data);
+}
+
struct nft_set *nf_tables_set_lookup(const struct nft_table *table,
const struct nlattr *nla);
struct nft_set *nf_tables_set_lookup_byid(const struct net *net,
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index c7e1a9d..5923ec5 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -15,6 +15,7 @@
#include <linux/log2.h>
#include <linux/jhash.h>
#include <linux/netlink.h>
+#include <linux/workqueue.h>
#include <linux/rhashtable.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
@@ -25,6 +26,7 @@
struct nft_hash {
struct rhashtable ht;
+ struct delayed_work gc_work;
};
struct nft_hash_elem {
@@ -62,6 +64,8 @@ static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
if (nft_data_cmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
return 1;
+ if (nft_set_elem_expired(&he->ext))
+ return 1;
if (!nft_set_elem_active(&he->ext, x->genmask))
return 1;
return 0;
@@ -107,6 +111,7 @@ static void nft_hash_activate(const struct nft_set *set,
struct nft_hash_elem *he = elem->priv;
nft_set_elem_change_active(set, &he->ext);
+ nft_set_elem_clear_busy(&he->ext);
}
static void *nft_hash_deactivate(const struct nft_set *set,
@@ -120,9 +125,15 @@ static void *nft_hash_deactivate(const struct nft_set *set,
.key = &elem->key,
};
+ rcu_read_lock();
he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
- if (he != NULL)
- nft_set_elem_change_active(set, &he->ext);
+ if (he != NULL) {
+ if (!nft_set_elem_mark_busy(&he->ext))
+ nft_set_elem_change_active(set, &he->ext);
+ else
+ he = NULL;
+ }
+ rcu_read_unlock();
return he;
}
@@ -170,6 +181,8 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
if (iter->count < iter->skip)
goto cont;
+ if (nft_set_elem_expired(&he->ext))
+ goto cont;
if (!nft_set_elem_active(&he->ext, genmask))
goto cont;
@@ -188,6 +201,54 @@ out:
rhashtable_walk_exit(&hti);
}
+static void nft_hash_gc(struct work_struct *work)
+{
+ const struct nft_set *set;
+ struct nft_hash_elem *he;
+ struct nft_hash *priv;
+ struct nft_set_gc_batch *gcb = NULL;
+ struct rhashtable_iter hti;
+ int err;
+
+ priv = container_of(work, struct nft_hash, gc_work.work);
+ set = nft_set_container_of(priv);
+
+ err = rhashtable_walk_init(&priv->ht, &hti);
+ if (err)
+ goto schedule;
+
+ err = rhashtable_walk_start(&hti);
+ if (err && err != -EAGAIN)
+ goto out;
+
+ while ((he = rhashtable_walk_next(&hti))) {
+ if (IS_ERR(he)) {
+ if (PTR_ERR(he) != -EAGAIN)
+ goto out;
+ continue;
+ }
+
+ if (!nft_set_elem_expired(&he->ext))
+ continue;
+ if (nft_set_elem_mark_busy(&he->ext))
+ continue;
+
+ gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
+ if (gcb == NULL)
+ goto out;
+ rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
+ nft_set_gc_batch_add(gcb, he);
+ }
+out:
+ rhashtable_walk_stop(&hti);
+ rhashtable_walk_exit(&hti);
+
+ nft_set_gc_batch_complete(gcb);
+schedule:
+ queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
+ nft_set_gc_interval(set));
+}
+
static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
{
return sizeof(struct nft_hash);
@@ -207,11 +268,20 @@ static int nft_hash_init(const struct nft_set *set,
{
struct nft_hash *priv = nft_set_priv(set);
struct rhashtable_params params = nft_hash_params;
+ int err;
params.nelem_hint = desc->size ?: NFT_HASH_ELEMENT_HINT;
params.key_len = set->klen;
- return rhashtable_init(&priv->ht, ¶ms);
+ err = rhashtable_init(&priv->ht, ¶ms);
+ if (err < 0)
+ return err;
+
+ INIT_DEFERRABLE_WORK(&priv->gc_work, nft_hash_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_hash_elem_destroy(void *ptr, void *arg)
@@ -223,6 +293,7 @@ static void nft_hash_destroy(const struct nft_set *set)
{
struct nft_hash *priv = nft_set_priv(set);
+ cancel_delayed_work_sync(&priv->gc_work);
rhashtable_free_and_destroy(&priv->ht, nft_hash_elem_destroy,
(void *)set);
}
@@ -264,7 +335,7 @@ static struct nft_set_ops nft_hash_ops __read_mostly = {
.remove = nft_hash_remove,
.lookup = nft_hash_lookup,
.walk = nft_hash_walk,
- .features = NFT_SET_MAP,
+ .features = NFT_SET_MAP | NFT_SET_TIMEOUT,
.owner = THIS_MODULE,
};
--
1.7.10.4
--
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