This patch adds a simple non-resizable hashtable implementation. If the
user specifies the set size, then this new faster hashtable flavour is
selected.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
v2: missing rcu read side lock.
net/netfilter/nft_set_hash.c | 210 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 202 insertions(+), 8 deletions(-)
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 466cb7092dfa..b2eab94362d6 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -371,14 +371,181 @@ static u32 nft_hash_buckets(u32 size)
static bool nft_rhash_estimate(const struct nft_set_desc *desc, u32 features,
struct nft_set_estimate *est)
{
- if (desc->size)
- est->size = sizeof(struct nft_rhash) +
- nft_hash_buckets(desc->size) *
- sizeof(struct nft_rhash_elem *) +
- desc->size * sizeof(struct nft_rhash_elem);
- else
- est->size = ~0;
+ est->size = ~0;
+ est->lookup = NFT_SET_CLASS_O_1;
+ est->space = NFT_SET_CLASS_O_N;
+
+ return true;
+}
+
+struct nft_hash {
+ u32 seed;
+ u32 buckets;
+ struct hlist_head table[];
+};
+
+struct nft_hash_elem {
+ struct hlist_node node;
+ struct nft_set_ext ext;
+};
+
+static bool nft_hash_lookup(const struct net *net, const struct nft_set *set,
+ const u32 *key, const struct nft_set_ext **ext)
+{
+ struct nft_hash *priv = nft_set_priv(set);
+ u8 genmask = nft_genmask_cur(net);
+ const struct nft_hash_elem *he;
+ u32 hash;
+
+ hash = jhash(key, set->klen, priv->seed);
+ hash = reciprocal_scale(hash, priv->buckets);
+ hlist_for_each_entry_rcu(he, &priv->table[hash], node) {
+ if (!memcmp(nft_set_ext_key(&he->ext), key, set->klen) &&
+ nft_set_elem_active(&he->ext, genmask)) {
+ *ext = &he->ext;
+ return true;
+ }
+ }
+ return false;
+}
+
+static int nft_hash_insert(const struct net *net, const struct nft_set *set,
+ const struct nft_set_elem *elem,
+ struct nft_set_ext **ext)
+{
+ struct nft_hash_elem *this = elem->priv, *he;
+ struct nft_hash *priv = nft_set_priv(set);
+ u8 genmask = nft_genmask_next(net);
+ u32 hash;
+
+ hash = jhash(nft_set_ext_key(&this->ext), set->klen, priv->seed);
+ hash = reciprocal_scale(hash, priv->buckets);
+ hlist_for_each_entry(he, &priv->table[hash], node) {
+ if (!memcmp(nft_set_ext_key(&this->ext),
+ nft_set_ext_key(&he->ext), set->klen) &&
+ nft_set_elem_active(&he->ext, genmask)) {
+ *ext = &he->ext;
+ return -EEXIST;
+ }
+ }
+ hlist_add_head_rcu(&this->node, &priv->table[hash]);
+ return 0;
+}
+
+static void nft_hash_activate(const struct net *net, const struct nft_set *set,
+ const struct nft_set_elem *elem)
+{
+ struct nft_hash_elem *he = elem->priv;
+
+ nft_set_elem_change_active(net, set, &he->ext);
+}
+
+static bool nft_hash_flush(const struct net *net,
+ const struct nft_set *set, void *priv)
+{
+ struct nft_hash_elem *he = priv;
+
+ nft_set_elem_change_active(net, set, &he->ext);
+ return true;
+}
+
+static void *nft_hash_deactivate(const struct net *net,
+ const struct nft_set *set,
+ const struct nft_set_elem *elem)
+{
+ struct nft_hash *priv = nft_set_priv(set);
+ struct nft_hash_elem *this = elem->priv, *he;
+ u8 genmask = nft_genmask_next(net);
+ u32 hash;
+
+ hash = jhash(nft_set_ext_key(&this->ext), set->klen, priv->seed);
+ hash = reciprocal_scale(hash, priv->buckets);
+ hlist_for_each_entry(he, &priv->table[hash], node) {
+ if (!memcmp(nft_set_ext_key(&this->ext), &elem->key.val,
+ set->klen) ||
+ nft_set_elem_active(&he->ext, genmask)) {
+ nft_set_elem_change_active(net, set, &he->ext);
+ return he;
+ }
+ }
+ return NULL;
+}
+
+static void nft_hash_remove(const struct net *net,
+ const struct nft_set *set,
+ const struct nft_set_elem *elem)
+{
+ struct nft_hash_elem *he = elem->priv;
+
+ hlist_del_rcu(&he->node);
+}
+
+static void nft_hash_walk(const struct nft_ctx *ctx, struct nft_set *set,
+ struct nft_set_iter *iter)
+{
+ struct nft_hash *priv = nft_set_priv(set);
+ struct nft_hash_elem *he;
+ struct nft_set_elem elem;
+ int i;
+
+ for (i = 0; i < priv->buckets; i++) {
+ hlist_for_each_entry_rcu(he, &priv->table[i], node) {
+ if (iter->count < iter->skip)
+ goto cont;
+ if (!nft_set_elem_active(&he->ext, iter->genmask))
+ goto cont;
+
+ elem.priv = he;
+
+ iter->err = iter->fn(ctx, set, iter, &elem);
+ if (iter->err < 0)
+ return;
+cont:
+ iter->count++;
+ }
+ }
+}
+
+static unsigned int nft_hash_privsize(const struct nlattr * const nla[],
+ const struct nft_set_desc *desc)
+{
+ return sizeof(struct nft_hash) +
+ nft_hash_buckets(desc->size) * sizeof(struct hlist_head);
+}
+
+static int nft_hash_init(const struct nft_set *set,
+ const struct nft_set_desc *desc,
+ const struct nlattr * const tb[])
+{
+ struct nft_hash *priv = nft_set_priv(set);
+
+ priv->buckets = nft_hash_buckets(desc->size);
+ get_random_bytes(&priv->seed, sizeof(priv->seed));
+
+ return 0;
+}
+
+static void nft_hash_destroy(const struct nft_set *set)
+{
+ struct nft_hash *priv = nft_set_priv(set);
+ struct nft_hash_elem *he;
+ struct hlist_node *next;
+ int i;
+
+ for (i = 0; i < priv->buckets; i++) {
+ hlist_for_each_entry_safe(he, next, &priv->table[i], node) {
+ hlist_del_rcu(&he->node);
+ nft_set_elem_destroy(set, he, true);
+ }
+ }
+}
+static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
+ struct nft_set_estimate *est)
+{
+ est->size = sizeof(struct nft_hash) +
+ nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
+ desc->size * sizeof(struct nft_hash_elem);
est->lookup = NFT_SET_CLASS_O_1;
est->space = NFT_SET_CLASS_O_N;
@@ -404,8 +571,35 @@ static struct nft_set_ops nft_rhash_ops __read_mostly = {
.features = NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
};
+static struct nft_set_ops nft_hash_ops __read_mostly = {
+ .type = &nft_hash_type,
+ .privsize = nft_hash_privsize,
+ .elemsize = offsetof(struct nft_hash_elem, ext),
+ .estimate = nft_hash_estimate,
+ .init = nft_hash_init,
+ .destroy = nft_hash_destroy,
+ .insert = nft_hash_insert,
+ .activate = nft_hash_activate,
+ .deactivate = nft_hash_deactivate,
+ .flush = nft_hash_flush,
+ .remove = nft_hash_remove,
+ .lookup = nft_hash_lookup,
+ .walk = nft_hash_walk,
+ .features = NFT_SET_MAP | NFT_SET_OBJECT,
+};
+
+static const struct nft_set_ops *
+nft_hash_select_ops(const struct nft_ctx *ctx, const struct nft_set_desc *desc,
+ u32 flags)
+{
+ if (desc->size)
+ return &nft_hash_ops;
+
+ return &nft_rhash_ops;
+}
+
static struct nft_set_type nft_hash_type __read_mostly = {
- .ops = &nft_rhash_ops,
+ .select_ops = nft_hash_select_ops,
.owner = THIS_MODULE,
};
--
2.1.4
--
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