netfilter: nft_limit: factor out shared code with per-byte limiting
This patch prepares the introduction of per-byte limiting.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c
index c79703e..c4d1b1b 100644
--- a/net/netfilter/nft_limit.c
+++ b/net/netfilter/nft_limit.c
@@ -27,65 +27,54 @@
u64 nsecs;
};
-static void nft_limit_pkts_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_pktinfo *pkt)
+static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost)
{
- struct nft_limit *priv = nft_expr_priv(expr);
- u64 now, tokens, cost = div_u64(priv->nsecs, priv->rate);
+ u64 now, tokens;
s64 delta;
spin_lock_bh(&limit_lock);
now = ktime_get_ns();
- tokens = priv->tokens + now - priv->last;
- if (tokens > priv->tokens_max)
- tokens = priv->tokens_max;
+ tokens = limit->tokens + now - limit->last;
+ if (tokens > limit->tokens_max)
+ tokens = limit->tokens_max;
- priv->last = now;
+ limit->last = now;
delta = tokens - cost;
if (delta >= 0) {
- priv->tokens = delta;
+ limit->tokens = delta;
spin_unlock_bh(&limit_lock);
- return;
+ return false;
}
- priv->tokens = tokens;
+ limit->tokens = tokens;
spin_unlock_bh(&limit_lock);
-
- regs->verdict.code = NFT_BREAK;
+ return true;
}
-static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = {
- [NFTA_LIMIT_RATE] = { .type = NLA_U64 },
- [NFTA_LIMIT_UNIT] = { .type = NLA_U64 },
-};
-
-static int nft_limit_init(const struct nft_ctx *ctx,
- const struct nft_expr *expr,
+static int nft_limit_init(struct nft_limit *limit,
const struct nlattr * const tb[])
{
- struct nft_limit *priv = nft_expr_priv(expr);
u64 unit;
if (tb[NFTA_LIMIT_RATE] == NULL ||
tb[NFTA_LIMIT_UNIT] == NULL)
return -EINVAL;
- priv->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE]));
+ limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE]));
unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT]));
- priv->nsecs = unit * NSEC_PER_SEC;
- if (priv->rate == 0 || priv->nsecs < unit)
+ limit->nsecs = unit * NSEC_PER_SEC;
+ if (limit->rate == 0 || limit->nsecs < unit)
return -EOVERFLOW;
- priv->tokens = priv->tokens_max = priv->nsecs;
- priv->last = ktime_get_ns();
+ limit->tokens = limit->tokens_max = limit->nsecs;
+ limit->last = ktime_get_ns();
+
return 0;
}
-static int nft_limit_dump(struct sk_buff *skb, const struct nft_expr *expr)
+static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit)
{
- const struct nft_limit *priv = nft_expr_priv(expr);
- u64 secs = div_u64(priv->nsecs, NSEC_PER_SEC);
+ u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC);
- if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(priv->rate)) ||
+ if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(limit->rate)) ||
nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs)))
goto nla_put_failure;
return 0;
@@ -94,13 +83,44 @@
return -1;
}
+static void nft_limit_pkts_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_limit *priv = nft_expr_priv(expr);
+
+ if (nft_limit_eval(priv, div_u64(priv->nsecs, priv->rate)))
+ regs->verdict.code = NFT_BREAK;
+}
+
+static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = {
+ [NFTA_LIMIT_RATE] = { .type = NLA_U64 },
+ [NFTA_LIMIT_UNIT] = { .type = NLA_U64 },
+};
+
+static int nft_limit_pkts_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_limit *priv = nft_expr_priv(expr);
+
+ return nft_limit_init(priv, tb);
+}
+
+static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_limit *priv = nft_expr_priv(expr);
+
+ return nft_limit_dump(skb, priv);
+}
+
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)),
.eval = nft_limit_pkts_eval,
- .init = nft_limit_init,
- .dump = nft_limit_dump,
+ .init = nft_limit_pkts_init,
+ .dump = nft_limit_pkts_dump,
};
static struct nft_expr_type nft_limit_type __read_mostly = {