From 9d0982927e79049675cb6c6c04a0ebb3dad5a434 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 26 Mar 2015 12:39:40 +0000 Subject: [PATCH] netfilter: nft_hash: add support for timeouts 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 Signed-off-by: Pablo Neira Ayuso --- 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 1ea13fcd388e..a785699329c9 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 c7e1a9d7d46f..5923ec547268 100644 --- a/net/netfilter/nft_hash.c +++ b/net/netfilter/nft_hash.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -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, }; -- 2.39.2