| /* |
| * 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; |
| int err; |
| |
| err = rhashtable_walk_init(&priv->ht, &hti, GFP_KERNEL); |
| 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, iter->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, GFP_KERNEL); |
| 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(); |