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- /*
- * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * Development of this code funded by Astaro AG (http://www.astaro.com/)
- */
- #include <linux/kernel.h>
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/list.h>
- #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>
- #include <net/netfilter/nf_tables.h>
- /* We target a hash table size of 4, element hint is 75% of final size */
- #define NFT_HASH_ELEMENT_HINT 3
- struct nft_hash {
- struct rhashtable ht;
- struct delayed_work gc_work;
- };
- struct nft_hash_elem {
- struct rhash_head node;
- struct nft_set_ext ext;
- };
- struct nft_hash_cmp_arg {
- const struct nft_set *set;
- const u32 *key;
- u8 genmask;
- };
- static const struct rhashtable_params nft_hash_params;
- static inline u32 nft_hash_key(const void *data, u32 len, u32 seed)
- {
- const struct nft_hash_cmp_arg *arg = data;
- return jhash(arg->key, len, seed);
- }
- static inline u32 nft_hash_obj(const void *data, u32 len, u32 seed)
- {
- const struct nft_hash_elem *he = data;
- return jhash(nft_set_ext_key(&he->ext), len, seed);
- }
- static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
- const void *ptr)
- {
- const struct nft_hash_cmp_arg *x = arg->key;
- const struct nft_hash_elem *he = ptr;
- if (memcmp(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;
- }
- static bool nft_hash_lookup(const struct nft_set *set, const u32 *key,
- const struct nft_set_ext **ext)
- {
- struct nft_hash *priv = nft_set_priv(set);
- const struct nft_hash_elem *he;
- struct nft_hash_cmp_arg arg = {
- .genmask = nft_genmask_cur(read_pnet(&set->pnet)),
- .set = set,
- .key = key,
- };
- he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
- if (he != NULL)
- *ext = &he->ext;
- return !!he;
- }
- static bool nft_hash_update(struct nft_set *set, const u32 *key,
- void *(*new)(struct nft_set *,
- const struct nft_expr *,
- struct nft_regs *regs),
- const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_set_ext **ext)
- {
- struct nft_hash *priv = nft_set_priv(set);
- struct nft_hash_elem *he;
- struct nft_hash_cmp_arg arg = {
- .genmask = NFT_GENMASK_ANY,
- .set = set,
- .key = key,
- };
- he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
- if (he != NULL)
- goto out;
- he = new(set, expr, regs);
- if (he == NULL)
- goto err1;
- if (rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
- nft_hash_params))
- goto err2;
- out:
- *ext = &he->ext;
- return true;
- err2:
- nft_set_elem_destroy(set, he);
- err1:
- return false;
- }
- static int nft_hash_insert(const struct nft_set *set,
- const struct nft_set_elem *elem)
- {
- struct nft_hash *priv = nft_set_priv(set);
- struct nft_hash_elem *he = elem->priv;
- struct nft_hash_cmp_arg arg = {
- .genmask = nft_genmask_next(read_pnet(&set->pnet)),
- .set = set,
- .key = elem->key.val.data,
- };
- return rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
- nft_hash_params);
- }
- static void nft_hash_activate(const struct nft_set *set,
- const struct nft_set_elem *elem)
- {
- 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,
- const struct nft_set_elem *elem)
- {
- struct nft_hash *priv = nft_set_priv(set);
- struct nft_hash_elem *he;
- struct nft_hash_cmp_arg arg = {
- .genmask = nft_genmask_next(read_pnet(&set->pnet)),
- .set = set,
- .key = elem->key.val.data,
- };
- rcu_read_lock();
- he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
- 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;
- }
- static void nft_hash_remove(const struct nft_set *set,
- const struct nft_set_elem *elem)
- {
- struct nft_hash *priv = nft_set_priv(set);
- struct nft_hash_elem *he = elem->priv;
- rhashtable_remove_fast(&priv->ht, &he->node, nft_hash_params);
- }
- static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
- struct nft_set_iter *iter)
- {
- struct nft_hash *priv = nft_set_priv(set);
- struct nft_hash_elem *he;
- struct rhashtable_iter hti;
- struct nft_set_elem elem;
- u8 genmask = nft_genmask_cur(read_pnet(&set->pnet));
- int err;
- err = rhashtable_walk_init(&priv->ht, &hti);
- iter->err = err;
- if (err)
- return;
- err = rhashtable_walk_start(&hti);
- if (err && err != -EAGAIN) {
- iter->err = err;
- goto out;
- }
- while ((he = rhashtable_walk_next(&hti))) {
- if (IS_ERR(he)) {
- err = PTR_ERR(he);
- if (err != -EAGAIN) {
- iter->err = err;
- goto out;
- }
- continue;
- }
- 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;
- elem.priv = he;
- iter->err = iter->fn(ctx, set, iter, &elem);
- if (iter->err < 0)
- goto out;
- cont:
- iter->count++;
- }
- out:
- rhashtable_walk_stop(&hti);
- rhashtable_walk_exit(&hti);
- }
- static void nft_hash_gc(struct work_struct *work)
- {
- 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);
- atomic_dec(&set->nelems);
- 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);
- }
- static const struct rhashtable_params nft_hash_params = {
- .head_offset = offsetof(struct nft_hash_elem, node),
- .hashfn = nft_hash_key,
- .obj_hashfn = nft_hash_obj,
- .obj_cmpfn = nft_hash_cmp,
- .automatic_shrinking = true,
- };
- 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);
- struct rhashtable_params params = nft_hash_params;
- int err;
- params.nelem_hint = desc->size ?: NFT_HASH_ELEMENT_HINT;
- params.key_len = set->klen;
- 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)
- {
- nft_set_elem_destroy((const struct nft_set *)arg, ptr);
- }
- 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);
- }
- static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
- struct nft_set_estimate *est)
- {
- unsigned int esize;
- esize = sizeof(struct nft_hash_elem);
- if (desc->size) {
- est->size = sizeof(struct nft_hash) +
- roundup_pow_of_two(desc->size * 4 / 3) *
- sizeof(struct nft_hash_elem *) +
- desc->size * esize;
- } else {
- /* Resizing happens when the load drops below 30% or goes
- * above 75%. The average of 52.5% load (approximated by 50%)
- * is used for the size estimation of the hash buckets,
- * meaning we calculate two buckets per element.
- */
- est->size = esize + 2 * sizeof(struct nft_hash_elem *);
- }
- est->class = NFT_SET_CLASS_O_1;
- return true;
- }
- static struct nft_set_ops nft_hash_ops __read_mostly = {
- .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,
- .remove = nft_hash_remove,
- .lookup = nft_hash_lookup,
- .update = nft_hash_update,
- .walk = nft_hash_walk,
- .features = NFT_SET_MAP | NFT_SET_TIMEOUT,
- .owner = THIS_MODULE,
- };
- static int __init nft_hash_module_init(void)
- {
- return nft_register_set(&nft_hash_ops);
- }
- static void __exit nft_hash_module_exit(void)
- {
- nft_unregister_set(&nft_hash_ops);
- }
- module_init(nft_hash_module_init);
- module_exit(nft_hash_module_exit);
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
- MODULE_ALIAS_NFT_SET();
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