// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2008-2014 Patrick McHardy <[email protected]>
*
* 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 nft_elem_priv priv;
struct rhash_head node;
struct nft_set_ext ext;
};
struct nft_rhash_cmp_arg {
const struct nft_set *set;
const u32 *key;
u8 genmask;
u64 tstamp;
};
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, x->tstamp))
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,
.tstamp = get_jiffies_64(),
};
he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
if (he != NULL)
*ext = &he->ext;
return !!he;
}
static struct nft_elem_priv *
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,
.tstamp = get_jiffies_64(),
};
he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
if (he != NULL)
return &he->priv;
return ERR_PTR(-ENOENT);
}
static bool nft_rhash_update(struct nft_set *set, const u32 *key,
struct nft_elem_priv *
(*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_elem_priv *elem_priv;
struct nft_rhash_cmp_arg arg = {
.genmask = NFT_GENMASK_ANY,
.set = set,
.key = key,
.tstamp = get_jiffies_64(),
};
he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
if (he != NULL)
goto out;
elem_priv = new(set, expr, regs);
if (!elem_priv)
goto err1;
he = nft_elem_priv_cast(elem_priv);
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->priv, true);
atomic_dec(&set->nelems);
he = prev;
}
out:
*ext = &he->ext;
return true;
err2:
nft_set_elem_destroy(set, &he->priv, 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_elem_priv **elem_priv)
{
struct nft_rhash_elem *he = nft_elem_priv_cast(elem->priv);
struct nft_rhash *priv = nft_set_priv(set);
struct nft_rhash_cmp_arg arg = {
.genmask = nft_genmask_next(net),
.set = set,
.key = elem->key.val.data,
.tstamp = nft_net_tstamp(net),
};
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) {
*elem_priv = &prev->priv;
return -EEXIST;
}
return 0;
}
static void nft_rhash_activate(const struct net *net, const struct nft_set *set,
struct nft_elem_priv *elem_priv)
{
struct nft_rhash_elem *he = nft_elem_priv_cast(elem_priv);
nft_clear(net, &he->ext);
}
static void nft_rhash_flush(const struct net *net,
const struct nft_set *set,
struct nft_elem_priv *elem_priv)
{
struct nft_rhash_elem *he = nft_elem_priv_cast(elem_priv);
nft_set_elem_change_active(net, set, &he->ext);
}
static struct nft_elem_priv *
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,
.tstamp = nft_net_tstamp(net),
};
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->priv;
}
static void nft_rhash_remove(const struct net *net,
const struct nft_set *set,
struct nft_elem_priv *elem_priv)
{
struct nft_rhash_elem *he = nft_elem_priv_cast(elem_priv);
struct nft_rhash *priv = nft_set_priv(set);
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;
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;
iter->err = iter->fn(ctx, set, iter, &he->priv);
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;
BUILD_BUG_ON(offsetof(struct nft_rhash_elem, priv) != 0);
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;
struct nft_rhash_elem *he = ptr;
nf_tables_set_elem_destroy(&rhash_ctx->ctx, rhash_ctx->set, &he->priv);
}
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 nft_elem_priv priv;
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 struct nft_elem_priv *
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->priv;
}
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_elem_priv **elem_priv)
{
struct nft_hash_elem *this = nft_elem_priv_cast(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)) {
*elem_priv = &he->priv;
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,
struct nft_elem_priv *elem_priv)
{
struct nft_hash_elem *he = nft_elem_priv_cast(elem_priv);
nft_clear(net, &he->ext);
}
static void nft_hash_flush(const struct net *net,
const struct nft_set *set,
struct nft_elem_priv *elem_priv)
{
struct nft_hash_elem *he = nft_elem_priv_cast(elem_priv);
nft_set_elem_change_active(net, set, &he->ext);
}
static struct nft_elem_priv *
nft_hash_deactivate(const struct net *net, const struct nft_set *set,
const struct nft_set_elem *elem)
{
struct nft_hash_elem *this = nft_elem_priv_cast(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(&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->priv;
}
}
return NULL;
}
static void nft_hash_remove(const struct net *net,
const struct nft_set *set,
struct nft_elem_priv *elem_priv)
{
struct nft_hash_elem *he = nft_elem_priv_cast(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;
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;
iter->err = iter->fn(ctx, set, iter, &he->priv);
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->priv);
}
}
}
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,
},
};