diff options
Diffstat (limited to 'net/netfilter/nft_set_hash.c')
-rw-r--r-- | net/netfilter/nft_set_hash.c | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c new file mode 100644 index 000000000..2013de934 --- /dev/null +++ b/net/netfilter/nft_set_hash.c @@ -0,0 +1,788 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> + * + * 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_core.h> + +/* We target a hash table size of 4, element hint is 75% of final size */ +#define NFT_RHASH_ELEMENT_HINT 3 + +struct nft_rhash { + struct rhashtable ht; + struct delayed_work gc_work; +}; + +struct nft_rhash_elem { + struct rhash_head node; + struct nft_set_ext ext; +}; + +struct nft_rhash_cmp_arg { + const struct nft_set *set; + const u32 *key; + u8 genmask; +}; + +static inline u32 nft_rhash_key(const void *data, u32 len, u32 seed) +{ + const struct nft_rhash_cmp_arg *arg = data; + + return jhash(arg->key, len, seed); +} + +static inline u32 nft_rhash_obj(const void *data, u32 len, u32 seed) +{ + const struct nft_rhash_elem *he = data; + + return jhash(nft_set_ext_key(&he->ext), len, seed); +} + +static inline int nft_rhash_cmp(struct rhashtable_compare_arg *arg, + const void *ptr) +{ + const struct nft_rhash_cmp_arg *x = arg->key; + const struct nft_rhash_elem *he = ptr; + + if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen)) + return 1; + if (nft_set_elem_is_dead(&he->ext)) + 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 const struct rhashtable_params nft_rhash_params = { + .head_offset = offsetof(struct nft_rhash_elem, node), + .hashfn = nft_rhash_key, + .obj_hashfn = nft_rhash_obj, + .obj_cmpfn = nft_rhash_cmp, + .automatic_shrinking = true, +}; + +INDIRECT_CALLABLE_SCOPE +bool nft_rhash_lookup(const struct net *net, const struct nft_set *set, + const u32 *key, const struct nft_set_ext **ext) +{ + struct nft_rhash *priv = nft_set_priv(set); + const struct nft_rhash_elem *he; + struct nft_rhash_cmp_arg arg = { + .genmask = nft_genmask_cur(net), + .set = set, + .key = key, + }; + + he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params); + if (he != NULL) + *ext = &he->ext; + + return !!he; +} + +static void *nft_rhash_get(const struct net *net, const struct nft_set *set, + const struct nft_set_elem *elem, unsigned int flags) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_elem *he; + struct nft_rhash_cmp_arg arg = { + .genmask = nft_genmask_cur(net), + .set = set, + .key = elem->key.val.data, + }; + + he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params); + if (he != NULL) + return he; + + return ERR_PTR(-ENOENT); +} + +static bool nft_rhash_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_rhash *priv = nft_set_priv(set); + struct nft_rhash_elem *he, *prev; + struct nft_rhash_cmp_arg arg = { + .genmask = NFT_GENMASK_ANY, + .set = set, + .key = key, + }; + + he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params); + if (he != NULL) + goto out; + + he = new(set, expr, regs); + if (he == NULL) + goto err1; + + prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node, + nft_rhash_params); + if (IS_ERR(prev)) + goto err2; + + /* Another cpu may race to insert the element with the same key */ + if (prev) { + nft_set_elem_destroy(set, he, true); + atomic_dec(&set->nelems); + he = prev; + } + +out: + *ext = &he->ext; + return true; + +err2: + nft_set_elem_destroy(set, he, true); + atomic_dec(&set->nelems); +err1: + return false; +} + +static int nft_rhash_insert(const struct net *net, const struct nft_set *set, + const struct nft_set_elem *elem, + struct nft_set_ext **ext) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_elem *he = elem->priv; + struct nft_rhash_cmp_arg arg = { + .genmask = nft_genmask_next(net), + .set = set, + .key = elem->key.val.data, + }; + struct nft_rhash_elem *prev; + + prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node, + nft_rhash_params); + if (IS_ERR(prev)) + return PTR_ERR(prev); + if (prev) { + *ext = &prev->ext; + return -EEXIST; + } + return 0; +} + +static void nft_rhash_activate(const struct net *net, const struct nft_set *set, + const struct nft_set_elem *elem) +{ + struct nft_rhash_elem *he = elem->priv; + + nft_set_elem_change_active(net, set, &he->ext); +} + +static bool nft_rhash_flush(const struct net *net, + const struct nft_set *set, void *priv) +{ + struct nft_rhash_elem *he = priv; + + nft_set_elem_change_active(net, set, &he->ext); + + return true; +} + +static void *nft_rhash_deactivate(const struct net *net, + const struct nft_set *set, + const struct nft_set_elem *elem) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_elem *he; + struct nft_rhash_cmp_arg arg = { + .genmask = nft_genmask_next(net), + .set = set, + .key = elem->key.val.data, + }; + + rcu_read_lock(); + he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params); + if (he) + nft_set_elem_change_active(net, set, &he->ext); + + rcu_read_unlock(); + + return he; +} + +static void nft_rhash_remove(const struct net *net, + const struct nft_set *set, + const struct nft_set_elem *elem) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_elem *he = elem->priv; + + rhashtable_remove_fast(&priv->ht, &he->node, nft_rhash_params); +} + +static bool nft_rhash_delete(const struct nft_set *set, + const u32 *key) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_cmp_arg arg = { + .genmask = NFT_GENMASK_ANY, + .set = set, + .key = key, + }; + struct nft_rhash_elem *he; + + he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params); + if (he == NULL) + return false; + + nft_set_elem_dead(&he->ext); + + return true; +} + +static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set, + struct nft_set_iter *iter) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_elem *he; + struct rhashtable_iter hti; + struct nft_set_elem elem; + + rhashtable_walk_enter(&priv->ht, &hti); + rhashtable_walk_start(&hti); + + while ((he = rhashtable_walk_next(&hti))) { + if (IS_ERR(he)) { + if (PTR_ERR(he) != -EAGAIN) { + iter->err = PTR_ERR(he); + break; + } + + continue; + } + + 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) + break; + +cont: + iter->count++; + } + rhashtable_walk_stop(&hti); + rhashtable_walk_exit(&hti); +} + +static bool nft_rhash_expr_needs_gc_run(const struct nft_set *set, + struct nft_set_ext *ext) +{ + struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext); + struct nft_expr *expr; + u32 size; + + nft_setelem_expr_foreach(expr, elem_expr, size) { + if (expr->ops->gc && + expr->ops->gc(read_pnet(&set->net), expr)) + return true; + } + + return false; +} + +static void nft_rhash_gc(struct work_struct *work) +{ + struct nftables_pernet *nft_net; + struct nft_set *set; + struct nft_rhash_elem *he; + struct nft_rhash *priv; + struct rhashtable_iter hti; + struct nft_trans_gc *gc; + struct net *net; + u32 gc_seq; + + priv = container_of(work, struct nft_rhash, gc_work.work); + set = nft_set_container_of(priv); + net = read_pnet(&set->net); + nft_net = nft_pernet(net); + gc_seq = READ_ONCE(nft_net->gc_seq); + + if (nft_set_gc_is_pending(set)) + goto done; + + gc = nft_trans_gc_alloc(set, gc_seq, GFP_KERNEL); + if (!gc) + goto done; + + rhashtable_walk_enter(&priv->ht, &hti); + rhashtable_walk_start(&hti); + + while ((he = rhashtable_walk_next(&hti))) { + if (IS_ERR(he)) { + nft_trans_gc_destroy(gc); + gc = NULL; + goto try_later; + } + + /* Ruleset has been updated, try later. */ + if (READ_ONCE(nft_net->gc_seq) != gc_seq) { + nft_trans_gc_destroy(gc); + gc = NULL; + goto try_later; + } + + if (nft_set_elem_is_dead(&he->ext)) + goto dead_elem; + + if (nft_set_ext_exists(&he->ext, NFT_SET_EXT_EXPRESSIONS) && + nft_rhash_expr_needs_gc_run(set, &he->ext)) + goto needs_gc_run; + + if (!nft_set_elem_expired(&he->ext)) + continue; +needs_gc_run: + nft_set_elem_dead(&he->ext); +dead_elem: + gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC); + if (!gc) + goto try_later; + + nft_trans_gc_elem_add(gc, he); + } + + gc = nft_trans_gc_catchall_async(gc, gc_seq); + +try_later: + /* catchall list iteration requires rcu read side lock. */ + rhashtable_walk_stop(&hti); + rhashtable_walk_exit(&hti); + + if (gc) + nft_trans_gc_queue_async_done(gc); + +done: + queue_delayed_work(system_power_efficient_wq, &priv->gc_work, + nft_set_gc_interval(set)); +} + +static u64 nft_rhash_privsize(const struct nlattr * const nla[], + const struct nft_set_desc *desc) +{ + return sizeof(struct nft_rhash); +} + +static void nft_rhash_gc_init(const struct nft_set *set) +{ + struct nft_rhash *priv = nft_set_priv(set); + + queue_delayed_work(system_power_efficient_wq, &priv->gc_work, + nft_set_gc_interval(set)); +} + +static int nft_rhash_init(const struct nft_set *set, + const struct nft_set_desc *desc, + const struct nlattr * const tb[]) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct rhashtable_params params = nft_rhash_params; + int err; + + params.nelem_hint = desc->size ?: NFT_RHASH_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_rhash_gc); + if (set->flags & (NFT_SET_TIMEOUT | NFT_SET_EVAL)) + nft_rhash_gc_init(set); + + return 0; +} + +struct nft_rhash_ctx { + const struct nft_ctx ctx; + const struct nft_set *set; +}; + +static void nft_rhash_elem_destroy(void *ptr, void *arg) +{ + struct nft_rhash_ctx *rhash_ctx = arg; + + nf_tables_set_elem_destroy(&rhash_ctx->ctx, rhash_ctx->set, ptr); +} + +static void nft_rhash_destroy(const struct nft_ctx *ctx, + const struct nft_set *set) +{ + struct nft_rhash *priv = nft_set_priv(set); + struct nft_rhash_ctx rhash_ctx = { + .ctx = *ctx, + .set = set, + }; + + cancel_delayed_work_sync(&priv->gc_work); + rhashtable_free_and_destroy(&priv->ht, nft_rhash_elem_destroy, + (void *)&rhash_ctx); +} + +/* Number of buckets is stored in u32, so cap our result to 1U<<31 */ +#define NFT_MAX_BUCKETS (1U << 31) + +static u32 nft_hash_buckets(u32 size) +{ + u64 val = div_u64((u64)size * 4, 3); + + if (val >= NFT_MAX_BUCKETS) + return NFT_MAX_BUCKETS; + + return roundup_pow_of_two(val); +} + +static bool nft_rhash_estimate(const struct nft_set_desc *desc, u32 features, + struct nft_set_estimate *est) +{ + 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; +}; + +INDIRECT_CALLABLE_SCOPE +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 void *nft_hash_get(const struct net *net, const struct nft_set *set, + const struct nft_set_elem *elem, unsigned int flags) +{ + struct nft_hash *priv = nft_set_priv(set); + u8 genmask = nft_genmask_cur(net); + struct nft_hash_elem *he; + u32 hash; + + hash = jhash(elem->key.val.data, 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), elem->key.val.data, set->klen) && + nft_set_elem_active(&he->ext, genmask)) + return he; + } + return ERR_PTR(-ENOENT); +} + +INDIRECT_CALLABLE_SCOPE +bool nft_hash_lookup_fast(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, k1, k2; + + k1 = *key; + hash = jhash_1word(k1, priv->seed); + hash = reciprocal_scale(hash, priv->buckets); + hlist_for_each_entry_rcu(he, &priv->table[hash], node) { + k2 = *(u32 *)nft_set_ext_key(&he->ext)->data; + if (k1 == k2 && + nft_set_elem_active(&he->ext, genmask)) { + *ext = &he->ext; + return true; + } + } + return false; +} + +static u32 nft_jhash(const struct nft_set *set, const struct nft_hash *priv, + const struct nft_set_ext *ext) +{ + const struct nft_data *key = nft_set_ext_key(ext); + u32 hash, k1; + + if (set->klen == 4) { + k1 = *(u32 *)key; + hash = jhash_1word(k1, priv->seed); + } else { + hash = jhash(key, set->klen, priv->seed); + } + hash = reciprocal_scale(hash, priv->buckets); + + return hash; +} + +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 = nft_jhash(set, priv, &this->ext); + 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 = nft_jhash(set, priv, &this->ext); + hlist_for_each_entry(he, &priv->table[hash], node) { + if (!memcmp(nft_set_ext_key(&he->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 u64 nft_hash_privsize(const struct nlattr * const nla[], + const struct nft_set_desc *desc) +{ + return sizeof(struct nft_hash) + + (u64)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_ctx *ctx, + 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); + nf_tables_set_elem_destroy(ctx, set, he); + } + } +} + +static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features, + struct nft_set_estimate *est) +{ + if (!desc->size) + return false; + + if (desc->klen == 4) + return false; + + est->size = sizeof(struct nft_hash) + + (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head) + + (u64)desc->size * sizeof(struct nft_hash_elem); + est->lookup = NFT_SET_CLASS_O_1; + est->space = NFT_SET_CLASS_O_N; + + return true; +} + +static bool nft_hash_fast_estimate(const struct nft_set_desc *desc, u32 features, + struct nft_set_estimate *est) +{ + if (!desc->size) + return false; + + if (desc->klen != 4) + return false; + + est->size = sizeof(struct nft_hash) + + (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head) + + (u64)desc->size * sizeof(struct nft_hash_elem); + est->lookup = NFT_SET_CLASS_O_1; + est->space = NFT_SET_CLASS_O_N; + + return true; +} + +const struct nft_set_type nft_set_rhash_type = { + .features = NFT_SET_MAP | NFT_SET_OBJECT | + NFT_SET_TIMEOUT | NFT_SET_EVAL, + .ops = { + .privsize = nft_rhash_privsize, + .elemsize = offsetof(struct nft_rhash_elem, ext), + .estimate = nft_rhash_estimate, + .init = nft_rhash_init, + .gc_init = nft_rhash_gc_init, + .destroy = nft_rhash_destroy, + .insert = nft_rhash_insert, + .activate = nft_rhash_activate, + .deactivate = nft_rhash_deactivate, + .flush = nft_rhash_flush, + .remove = nft_rhash_remove, + .lookup = nft_rhash_lookup, + .update = nft_rhash_update, + .delete = nft_rhash_delete, + .walk = nft_rhash_walk, + .get = nft_rhash_get, + }, +}; + +const struct nft_set_type nft_set_hash_type = { + .features = NFT_SET_MAP | NFT_SET_OBJECT, + .ops = { + .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, + .get = nft_hash_get, + }, +}; + +const struct nft_set_type nft_set_hash_fast_type = { + .features = NFT_SET_MAP | NFT_SET_OBJECT, + .ops = { + .privsize = nft_hash_privsize, + .elemsize = offsetof(struct nft_hash_elem, ext), + .estimate = nft_hash_fast_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_fast, + .walk = nft_hash_walk, + .get = nft_hash_get, + }, +}; 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