diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /net/netfilter/nft_hash.c |
Initial import
Diffstat (limited to 'net/netfilter/nft_hash.c')
-rw-r--r-- | net/netfilter/nft_hash.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c new file mode 100644 index 000000000..3f9d45d3d --- /dev/null +++ b/net/netfilter/nft_hash.c @@ -0,0 +1,394 @@ +/* + * 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(); |