netfilter: nft_limit: move stateful fields out of expression data

In preparation for the rule blob representation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2022-01-09 17:11:18 +01:00
parent 369b6cb5d3
commit 3b9e2ea6c1

View File

@ -14,10 +14,14 @@
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
struct nft_limit_priv {
struct nft_limit {
spinlock_t lock;
u64 last;
u64 tokens;
};
struct nft_limit_priv {
struct nft_limit *limit;
u64 tokens_max;
u64 rate;
u64 nsecs;
@ -30,21 +34,21 @@ static inline bool nft_limit_eval(struct nft_limit_priv *priv, u64 cost)
u64 now, tokens;
s64 delta;
spin_lock_bh(&priv->lock);
spin_lock_bh(&priv->limit->lock);
now = ktime_get_ns();
tokens = priv->tokens + now - priv->last;
tokens = priv->limit->tokens + now - priv->limit->last;
if (tokens > priv->tokens_max)
tokens = priv->tokens_max;
priv->last = now;
priv->limit->last = now;
delta = tokens - cost;
if (delta >= 0) {
priv->tokens = delta;
spin_unlock_bh(&priv->lock);
priv->limit->tokens = delta;
spin_unlock_bh(&priv->limit->lock);
return priv->invert;
}
priv->tokens = tokens;
spin_unlock_bh(&priv->lock);
priv->limit->tokens = tokens;
spin_unlock_bh(&priv->limit->lock);
return !priv->invert;
}
@ -86,8 +90,12 @@ static int nft_limit_init(struct nft_limit_priv *priv,
priv->rate);
}
priv->tokens = tokens;
priv->tokens_max = priv->tokens;
priv->limit = kmalloc(sizeof(*priv->limit), GFP_KERNEL);
if (!priv->limit)
return -ENOMEM;
priv->limit->tokens = tokens;
priv->tokens_max = priv->limit->tokens;
if (tb[NFTA_LIMIT_FLAGS]) {
u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS]));
@ -95,8 +103,8 @@ static int nft_limit_init(struct nft_limit_priv *priv,
if (flags & NFT_LIMIT_F_INV)
priv->invert = true;
}
priv->last = ktime_get_ns();
spin_lock_init(&priv->lock);
priv->limit->last = ktime_get_ns();
spin_lock_init(&priv->limit->lock);
return 0;
}
@ -121,6 +129,32 @@ nla_put_failure:
return -1;
}
static void nft_limit_destroy(const struct nft_ctx *ctx,
const struct nft_limit_priv *priv)
{
kfree(priv->limit);
}
static int nft_limit_clone(struct nft_limit_priv *priv_dst,
const struct nft_limit_priv *priv_src)
{
priv_dst->tokens_max = priv_src->tokens_max;
priv_dst->rate = priv_src->rate;
priv_dst->nsecs = priv_src->nsecs;
priv_dst->burst = priv_src->burst;
priv_dst->invert = priv_src->invert;
priv_dst->limit = kmalloc(sizeof(*priv_dst->limit), GFP_ATOMIC);
if (priv_dst->limit)
return -ENOMEM;
spin_lock_init(&priv_dst->limit->lock);
priv_dst->limit->tokens = priv_src->tokens_max;
priv_dst->limit->last = ktime_get_ns();
return 0;
}
struct nft_limit_priv_pkts {
struct nft_limit_priv limit;
u64 cost;
@ -166,12 +200,30 @@ static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr)
return nft_limit_dump(skb, &priv->limit, NFT_LIMIT_PKTS);
}
static void nft_limit_pkts_destroy(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
const struct nft_limit_priv_pkts *priv = nft_expr_priv(expr);
nft_limit_destroy(ctx, &priv->limit);
}
static int nft_limit_pkts_clone(struct nft_expr *dst, const struct nft_expr *src)
{
struct nft_limit_priv_pkts *priv_dst = nft_expr_priv(dst);
struct nft_limit_priv_pkts *priv_src = nft_expr_priv(src);
return nft_limit_clone(&priv_dst->limit, &priv_src->limit);
}
static struct nft_expr_type nft_limit_type;
static const struct nft_expr_ops nft_limit_pkts_ops = {
.type = &nft_limit_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_limit_priv_pkts)),
.eval = nft_limit_pkts_eval,
.init = nft_limit_pkts_init,
.destroy = nft_limit_pkts_destroy,
.clone = nft_limit_pkts_clone,
.dump = nft_limit_pkts_dump,
};
@ -203,12 +255,30 @@ static int nft_limit_bytes_dump(struct sk_buff *skb,
return nft_limit_dump(skb, priv, NFT_LIMIT_PKT_BYTES);
}
static void nft_limit_bytes_destroy(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
const struct nft_limit_priv *priv = nft_expr_priv(expr);
nft_limit_destroy(ctx, priv);
}
static int nft_limit_bytes_clone(struct nft_expr *dst, const struct nft_expr *src)
{
struct nft_limit_priv *priv_dst = nft_expr_priv(dst);
struct nft_limit_priv *priv_src = nft_expr_priv(src);
return nft_limit_clone(priv_dst, priv_src);
}
static const struct nft_expr_ops nft_limit_bytes_ops = {
.type = &nft_limit_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_limit_priv)),
.eval = nft_limit_bytes_eval,
.init = nft_limit_bytes_init,
.dump = nft_limit_bytes_dump,
.clone = nft_limit_bytes_clone,
.destroy = nft_limit_bytes_destroy,
};
static const struct nft_expr_ops *