1 files changed, 124 insertions, 0 deletions
diff --git a/net/netfilter/xt_REDIRECT.c b/net/netfilter/xt_REDIRECT.c
new file mode 100644
index 000000000..ff66b56a3
--- /dev/null
+++ b/net/netfilter/xt_REDIRECT.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6
+ * NAT funded by Astaro.
+ */
+
+#include <linux/if.h>
+#include <linux/inetdevice.h>
+#include <linux/ip.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter.h>
+#include <linux/types.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter/x_tables.h>
+#include <net/addrconf.h>
+#include <net/checksum.h>
+#include <net/protocol.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_redirect.h>
+
+static unsigned int
+redirect_tg6(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	return nf_nat_redirect_ipv6(skb, par->targinfo, xt_hooknum(par));
+}
+
+static int redirect_tg6_checkentry(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_range2 *range = par->targinfo;
+
+	if (range->flags & NF_NAT_RANGE_MAP_IPS)
+		return -EINVAL;
+
+	return nf_ct_netns_get(par->net, par->family);
+}
+
+static void redirect_tg_destroy(const struct xt_tgdtor_param *par)
+{
+	nf_ct_netns_put(par->net, par->family);
+}
+
+static int redirect_tg4_check(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+
+	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
+		pr_debug("bad MAP_IPS.\n");
+		return -EINVAL;
+	}
+	if (mr->rangesize != 1) {
+		pr_debug("bad rangesize %u.\n", mr->rangesize);
+		return -EINVAL;
+	}
+	return nf_ct_netns_get(par->net, par->family);
+}
+
+static unsigned int
+redirect_tg4(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+	struct nf_nat_range2 range = {
+		.flags       = mr->range[0].flags,
+		.min_proto   = mr->range[0].min,
+		.max_proto   = mr->range[0].max,
+	};
+
+	return nf_nat_redirect_ipv4(skb, &range, xt_hooknum(par));
+}
+
+static struct xt_target redirect_tg_reg[] __read_mostly = {
+	{
+		.name       = "REDIRECT",
+		.family     = NFPROTO_IPV6,
+		.revision   = 0,
+		.table      = "nat",
+		.checkentry = redirect_tg6_checkentry,
+		.destroy    = redirect_tg_destroy,
+		.target     = redirect_tg6,
+		.targetsize = sizeof(struct nf_nat_range),
+		.hooks      = (1 << NF_INET_PRE_ROUTING) |
+		              (1 << NF_INET_LOCAL_OUT),
+		.me         = THIS_MODULE,
+	},
+	{
+		.name       = "REDIRECT",
+		.family     = NFPROTO_IPV4,
+		.revision   = 0,
+		.table      = "nat",
+		.target     = redirect_tg4,
+		.checkentry = redirect_tg4_check,
+		.destroy    = redirect_tg_destroy,
+		.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
+		.hooks      = (1 << NF_INET_PRE_ROUTING) |
+		              (1 << NF_INET_LOCAL_OUT),
+		.me         = THIS_MODULE,
+	},
+};
+
+static int __init redirect_tg_init(void)
+{
+	return xt_register_targets(redirect_tg_reg,
+				   ARRAY_SIZE(redirect_tg_reg));
+}
+
+static void __exit redirect_tg_exit(void)
+{
+	xt_unregister_targets(redirect_tg_reg, ARRAY_SIZE(redirect_tg_reg));
+}
+
+module_init(redirect_tg_init);
+module_exit(redirect_tg_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
+MODULE_ALIAS("ip6t_REDIRECT");
+MODULE_ALIAS("ipt_REDIRECT");