| /* |
| * 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/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_elem { |
| struct rhash_head node; |
| struct nft_data key; |
| struct nft_data data[]; |
| }; |
| |
| static bool nft_hash_lookup(const struct nft_set *set, |
| const struct nft_data *key, |
| struct nft_data *data) |
| { |
| const struct rhashtable *priv = nft_set_priv(set); |
| const struct nft_hash_elem *he; |
| |
| he = rhashtable_lookup(priv, key); |
| if (he && set->flags & NFT_SET_MAP) |
| nft_data_copy(data, he->data); |
| |
| return !!he; |
| } |
| |
| static int nft_hash_insert(const struct nft_set *set, |
| const struct nft_set_elem *elem) |
| { |
| struct rhashtable *priv = nft_set_priv(set); |
| struct nft_hash_elem *he; |
| unsigned int size; |
| |
| if (elem->flags != 0) |
| return -EINVAL; |
| |
| size = sizeof(*he); |
| if (set->flags & NFT_SET_MAP) |
| size += sizeof(he->data[0]); |
| |
| he = kzalloc(size, GFP_KERNEL); |
| if (he == NULL) |
| return -ENOMEM; |
| |
| nft_data_copy(&he->key, &elem->key); |
| if (set->flags & NFT_SET_MAP) |
| nft_data_copy(he->data, &elem->data); |
| |
| rhashtable_insert(priv, &he->node); |
| |
| return 0; |
| } |
| |
| static void nft_hash_elem_destroy(const struct nft_set *set, |
| struct nft_hash_elem *he) |
| { |
| nft_data_uninit(&he->key, NFT_DATA_VALUE); |
| if (set->flags & NFT_SET_MAP) |
| nft_data_uninit(he->data, set->dtype); |
| kfree(he); |
| } |
| |
| static void nft_hash_remove(const struct nft_set *set, |
| const struct nft_set_elem *elem) |
| { |
| struct rhashtable *priv = nft_set_priv(set); |
| |
| rhashtable_remove(priv, elem->cookie); |
| synchronize_rcu(); |
| kfree(elem->cookie); |
| } |
| |
| struct nft_compare_arg { |
| const struct nft_set *set; |
| struct nft_set_elem *elem; |
| }; |
| |
| static bool nft_hash_compare(void *ptr, void *arg) |
| { |
| struct nft_hash_elem *he = ptr; |
| struct nft_compare_arg *x = arg; |
| |
| if (!nft_data_cmp(&he->key, &x->elem->key, x->set->klen)) { |
| x->elem->cookie = he; |
| x->elem->flags = 0; |
| if (x->set->flags & NFT_SET_MAP) |
| nft_data_copy(&x->elem->data, he->data); |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem) |
| { |
| const struct rhashtable *priv = nft_set_priv(set); |
| struct nft_compare_arg arg = { |
| .set = set, |
| .elem = elem, |
| }; |
| |
| if (rhashtable_lookup_compare(priv, &elem->key, |
| &nft_hash_compare, &arg)) |
| return 0; |
| |
| return -ENOENT; |
| } |
| |
| static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set, |
| struct nft_set_iter *iter) |
| { |
| const struct rhashtable *priv = nft_set_priv(set); |
| const struct bucket_table *tbl; |
| const struct nft_hash_elem *he; |
| struct nft_set_elem elem; |
| unsigned int i; |
| |
| tbl = rht_dereference_rcu(priv->tbl, priv); |
| for (i = 0; i < tbl->size; i++) { |
| struct rhash_head *pos; |
| |
| rht_for_each_entry_rcu(he, pos, tbl, i, node) { |
| if (iter->count < iter->skip) |
| goto cont; |
| |
| memcpy(&elem.key, &he->key, sizeof(elem.key)); |
| if (set->flags & NFT_SET_MAP) |
| memcpy(&elem.data, he->data, sizeof(elem.data)); |
| elem.flags = 0; |
| |
| 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[]) |
| { |
| return sizeof(struct rhashtable); |
| } |
| |
| #ifdef CONFIG_PROVE_LOCKING |
| static int lockdep_nfnl_lock_is_held(void *parent) |
| { |
| return lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES); |
| } |
| #endif |
| |
| static int nft_hash_init(const struct nft_set *set, |
| const struct nft_set_desc *desc, |
| const struct nlattr * const tb[]) |
| { |
| struct rhashtable *priv = nft_set_priv(set); |
| struct rhashtable_params params = { |
| .nelem_hint = desc->size ? : NFT_HASH_ELEMENT_HINT, |
| .head_offset = offsetof(struct nft_hash_elem, node), |
| .key_offset = offsetof(struct nft_hash_elem, key), |
| .key_len = set->klen, |
| .hashfn = jhash, |
| .grow_decision = rht_grow_above_75, |
| .shrink_decision = rht_shrink_below_30, |
| #ifdef CONFIG_PROVE_LOCKING |
| .mutex_is_held = lockdep_nfnl_lock_is_held, |
| #endif |
| }; |
| |
| return rhashtable_init(priv, ¶ms); |
| } |
| |
| static void nft_hash_destroy(const struct nft_set *set) |
| { |
| const struct rhashtable *priv = nft_set_priv(set); |
| const struct bucket_table *tbl = priv->tbl; |
| struct nft_hash_elem *he; |
| struct rhash_head *pos, *next; |
| unsigned int i; |
| |
| for (i = 0; i < tbl->size; i++) { |
| rht_for_each_entry_safe(he, pos, next, tbl, i, node) |
| nft_hash_elem_destroy(set, he); |
| } |
| rhashtable_destroy(priv); |
| } |
| |
| 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 (features & NFT_SET_MAP) |
| esize += FIELD_SIZEOF(struct nft_hash_elem, data[0]); |
| |
| if (desc->size) { |
| est->size = sizeof(struct rhashtable) + |
| 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, |
| .estimate = nft_hash_estimate, |
| .init = nft_hash_init, |
| .destroy = nft_hash_destroy, |
| .get = nft_hash_get, |
| .insert = nft_hash_insert, |
| .remove = nft_hash_remove, |
| .lookup = nft_hash_lookup, |
| .walk = nft_hash_walk, |
| .features = NFT_SET_MAP, |
| .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(); |