1 files changed, 121 insertions, 0 deletions
diff --git a/net/netfilter/nft_quota.c b/net/netfilter/nft_quota.c
new file mode 100644
index 000000000000..6eafbf987ed9
--- /dev/null
+++ b/net/netfilter/nft_quota.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/atomic.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+
+struct nft_quota {
+	u64		quota;
+	bool		invert;
+	atomic64_t	remain;
+};
+
+static inline long nft_quota(struct nft_quota *priv,
+			     const struct nft_pktinfo *pkt)
+{
+	return atomic64_sub_return(pkt->skb->len, &priv->remain);
+}
+
+static void nft_quota_eval(const struct nft_expr *expr,
+			   struct nft_regs *regs,
+			   const struct nft_pktinfo *pkt)
+{
+	struct nft_quota *priv = nft_expr_priv(expr);
+
+	if (nft_quota(priv, pkt) < 0 && !priv->invert)
+		regs->verdict.code = NFT_BREAK;
+}
+
+static const struct nla_policy nft_quota_policy[NFTA_QUOTA_MAX + 1] = {
+	[NFTA_QUOTA_BYTES]	= { .type = NLA_U64 },
+	[NFTA_QUOTA_FLAGS]	= { .type = NLA_U32 },
+};
+
+static int nft_quota_init(const struct nft_ctx *ctx,
+			  const struct nft_expr *expr,
+			  const struct nlattr * const tb[])
+{
+	struct nft_quota *priv = nft_expr_priv(expr);
+	u32 flags = 0;
+	u64 quota;
+
+	if (!tb[NFTA_QUOTA_BYTES])
+		return -EINVAL;
+
+	quota = be64_to_cpu(nla_get_be64(tb[NFTA_QUOTA_BYTES]));
+	if (quota > S64_MAX)
+		return -EOVERFLOW;
+
+	if (tb[NFTA_QUOTA_FLAGS]) {
+		flags = ntohl(nla_get_be32(tb[NFTA_QUOTA_FLAGS]));
+		if (flags & ~NFT_QUOTA_F_INV)
+			return -EINVAL;
+	}
+
+	priv->quota = quota;
+	priv->invert = (flags & NFT_QUOTA_F_INV) ? true : false;
+	atomic64_set(&priv->remain, quota);
+
+	return 0;
+}
+
+static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+	const struct nft_quota *priv = nft_expr_priv(expr);
+	u32 flags = priv->invert ? NFT_QUOTA_F_INV : 0;
+
+	if (nla_put_be64(skb, NFTA_QUOTA_BYTES, cpu_to_be64(priv->quota),
+			 NFTA_QUOTA_PAD) ||
+	    nla_put_be32(skb, NFTA_QUOTA_FLAGS, htonl(flags)))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static struct nft_expr_type nft_quota_type;
+static const struct nft_expr_ops nft_quota_ops = {
+	.type		= &nft_quota_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_quota)),
+	.eval		= nft_quota_eval,
+	.init		= nft_quota_init,
+	.dump		= nft_quota_dump,
+};
+
+static struct nft_expr_type nft_quota_type __read_mostly = {
+	.name		= "quota",
+	.ops		= &nft_quota_ops,
+	.policy		= nft_quota_policy,
+	.maxattr	= NFTA_QUOTA_MAX,
+	.flags		= NFT_EXPR_STATEFUL,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nft_quota_module_init(void)
+{
+        return nft_register_expr(&nft_quota_type);
+}
+
+static void __exit nft_quota_module_exit(void)
+{
+        nft_unregister_expr(&nft_quota_type);
+}
+
+module_init(nft_quota_module_init);
+module_exit(nft_quota_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_ALIAS_NFT_EXPR("quota");