1 files changed, 112 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/nft_dup_ipv4.c b/net/ipv4/netfilter/nft_dup_ipv4.c
new file mode 100644
index 000000000..a522c3a3b
--- /dev/null
+++ b/net/ipv4/netfilter/nft_dup_ipv4.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/ipv4/nf_dup_ipv4.h>
+
+struct nft_dup_ipv4 {
+	u8	sreg_addr;
+	u8	sreg_dev;
+};
+
+static void nft_dup_ipv4_eval(const struct nft_expr *expr,
+			      struct nft_regs *regs,
+			      const struct nft_pktinfo *pkt)
+{
+	struct nft_dup_ipv4 *priv = nft_expr_priv(expr);
+	struct in_addr gw = {
+		.s_addr = (__force __be32)regs->data[priv->sreg_addr],
+	};
+	int oif = priv->sreg_dev ? regs->data[priv->sreg_dev] : -1;
+
+	nf_dup_ipv4(nft_net(pkt), pkt->skb, nft_hook(pkt), &gw, oif);
+}
+
+static int nft_dup_ipv4_init(const struct nft_ctx *ctx,
+			     const struct nft_expr *expr,
+			     const struct nlattr * const tb[])
+{
+	struct nft_dup_ipv4 *priv = nft_expr_priv(expr);
+	int err;
+
+	if (tb[NFTA_DUP_SREG_ADDR] == NULL)
+		return -EINVAL;
+
+	err = nft_parse_register_load(tb[NFTA_DUP_SREG_ADDR], &priv->sreg_addr,
+				      sizeof(struct in_addr));
+	if (err < 0)
+		return err;
+
+	if (tb[NFTA_DUP_SREG_DEV])
+		err = nft_parse_register_load(tb[NFTA_DUP_SREG_DEV],
+					      &priv->sreg_dev, sizeof(int));
+
+	return err;
+}
+
+static int nft_dup_ipv4_dump(struct sk_buff *skb,
+			     const struct nft_expr *expr, bool reset)
+{
+	struct nft_dup_ipv4 *priv = nft_expr_priv(expr);
+
+	if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr))
+		goto nla_put_failure;
+	if (priv->sreg_dev &&
+	    nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static struct nft_expr_type nft_dup_ipv4_type;
+static const struct nft_expr_ops nft_dup_ipv4_ops = {
+	.type		= &nft_dup_ipv4_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv4)),
+	.eval		= nft_dup_ipv4_eval,
+	.init		= nft_dup_ipv4_init,
+	.dump		= nft_dup_ipv4_dump,
+	.reduce		= NFT_REDUCE_READONLY,
+};
+
+static const struct nla_policy nft_dup_ipv4_policy[NFTA_DUP_MAX + 1] = {
+	[NFTA_DUP_SREG_ADDR]	= { .type = NLA_U32 },
+	[NFTA_DUP_SREG_DEV]	= { .type = NLA_U32 },
+};
+
+static struct nft_expr_type nft_dup_ipv4_type __read_mostly = {
+	.family		= NFPROTO_IPV4,
+	.name		= "dup",
+	.ops		= &nft_dup_ipv4_ops,
+	.policy		= nft_dup_ipv4_policy,
+	.maxattr	= NFTA_DUP_MAX,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nft_dup_ipv4_module_init(void)
+{
+	return nft_register_expr(&nft_dup_ipv4_type);
+}
+
+static void __exit nft_dup_ipv4_module_exit(void)
+{
+	nft_unregister_expr(&nft_dup_ipv4_type);
+}
+
+module_init(nft_dup_ipv4_module_init);
+module_exit(nft_dup_ipv4_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup");
+MODULE_DESCRIPTION("IPv4 nftables packet duplication support");