From: Arturo Borrero <arturo.borrero.glez@xxxxxxxxx>
This new expression provides NAT in the redirect flavour, which is to
redirect packets to local machine.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nft_redir.h | 21 +++++++
include/uapi/linux/netfilter/nf_tables.h | 16 +++++
net/ipv4/netfilter/Kconfig | 9 +++
net/ipv4/netfilter/Makefile | 1 +
net/ipv4/netfilter/nft_redir_ipv4.c | 77 +++++++++++++++++++++++
net/ipv6/netfilter/Kconfig | 9 +++
net/ipv6/netfilter/Makefile | 1 +
net/ipv6/netfilter/nft_redir_ipv6.c | 77 +++++++++++++++++++++++
net/netfilter/Kconfig | 9 +++
net/netfilter/Makefile | 1 +
net/netfilter/nft_redir.c | 98 ++++++++++++++++++++++++++++++
11 files changed, 319 insertions(+)
create mode 100644 include/net/netfilter/nft_redir.h
create mode 100644 net/ipv4/netfilter/nft_redir_ipv4.c
create mode 100644 net/ipv6/netfilter/nft_redir_ipv6.c
create mode 100644 net/netfilter/nft_redir.c
diff --git a/include/net/netfilter/nft_redir.h b/include/net/netfilter/nft_redir.h
new file mode 100644
index 0000000..a2d6754
--- /dev/null
+++ b/include/net/netfilter/nft_redir.h
@@ -0,0 +1,21 @@
+#ifndef _NFT_REDIR_H_
+#define _NFT_REDIR_H_
+
+struct nft_redir {
+ enum nft_registers sreg_proto_min:8;
+ enum nft_registers sreg_proto_max:8;
+ u16 flags;
+};
+
+extern const struct nla_policy nft_redir_policy[];
+
+int nft_redir_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[]);
+
+int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr);
+
+int nft_redir_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nft_data **data);
+
+#endif /* _NFT_REDIR_H_ */
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index f31fe7b..16f62a5 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -838,6 +838,22 @@ enum nft_masq_attributes {
#define NFTA_MASQ_MAX (__NFTA_MASQ_MAX - 1)
/**
+ * enum nft_redir_attributes - nf_tables redirect expression netlink attributes
+ *
+ * @NFTA_REDIR_REG_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers)
+ * @NFTA_REDIR_REG_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers)
+ * @NFTA_REDIR_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32)
+ */
+enum nft_redir_attributes {
+ NFTA_REDIR_UNSPEC,
+ NFTA_REDIR_REG_PROTO_MIN,
+ NFTA_REDIR_REG_PROTO_MAX,
+ NFTA_REDIR_FLAGS,
+ __NFTA_REDIR_MAX
+};
+#define NFTA_REDIR_MAX (__NFTA_REDIR_MAX - 1)
+
+/**
* enum nft_gen_attributes - nf_tables ruleset generation attributes
*
* @NFTA_GEN_ID: Ruleset generation ID (NLA_U32)
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index a300e2c..8358b2d 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -119,6 +119,15 @@ config NFT_MASQ_IPV4
This is the expression that provides IPv4 masquerading support for
nf_tables.
+config NFT_REDIR_IPV4
+ tristate "IPv4 redirect support for nf_tables"
+ depends on NF_TABLES_IPV4
+ depends on NFT_REDIR
+ select NF_NAT_REDIRECT_IPV4
+ help
+ This is the expression that provides IPv4 redirect support for
+ nf_tables.
+
config NF_NAT_SNMP_BASIC
tristate "Basic SNMP-ALG support"
depends on NF_CONNTRACK_SNMP
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 34e436c..902bcd1 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV4) += nft_chain_route_ipv4.o
obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o
obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o
obj-$(CONFIG_NFT_MASQ_IPV4) += nft_masq_ipv4.o
+obj-$(CONFIG_NFT_REDIR_IPV4) += nft_redir_ipv4.o
obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o
# generic IP tables
diff --git a/net/ipv4/netfilter/nft_redir_ipv4.c b/net/ipv4/netfilter/nft_redir_ipv4.c
new file mode 100644
index 0000000..643c596
--- /dev/null
+++ b/net/ipv4/netfilter/nft_redir_ipv4.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
+ *
+ * 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/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/ipv4/nf_nat_redirect.h>
+#include <net/netfilter/nft_redir.h>
+
+static void nft_redir_ipv4_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_redir *priv = nft_expr_priv(expr);
+ struct nf_nat_ipv4_multi_range_compat mr;
+ unsigned int verdict;
+
+ memset(&mr, 0, sizeof(mr));
+ if (priv->sreg_proto_min) {
+ mr.range[0].min.all = (__force __be16)
+ data[priv->sreg_proto_min].data[0];
+ mr.range[0].max.all = (__force __be16)
+ data[priv->sreg_proto_max].data[0];
+ mr.range[0].flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+ }
+
+ mr.range[0].flags |= priv->flags;
+
+ verdict = nf_nat_redirect_ipv4(pkt->skb, &mr, pkt->ops->hooknum);
+ data[NFT_REG_VERDICT].verdict = verdict;
+}
+
+static struct nft_expr_type nft_redir_ipv4_type;
+static const struct nft_expr_ops nft_redir_ipv4_ops = {
+ .type = &nft_redir_ipv4_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_redir)),
+ .eval = nft_redir_ipv4_eval,
+ .init = nft_redir_init,
+ .dump = nft_redir_dump,
+ .validate = nft_redir_validate,
+};
+
+static struct nft_expr_type nft_redir_ipv4_type __read_mostly = {
+ .family = NFPROTO_IPV4,
+ .name = "redir",
+ .ops = &nft_redir_ipv4_ops,
+ .policy = nft_redir_policy,
+ .maxattr = NFTA_REDIR_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_redir_ipv4_module_init(void)
+{
+ return nft_register_expr(&nft_redir_ipv4_type);
+}
+
+static void __exit nft_redir_ipv4_module_exit(void)
+{
+ nft_unregister_expr(&nft_redir_ipv4_type);
+}
+
+module_init(nft_redir_ipv4_module_init);
+module_exit(nft_redir_ipv4_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "redir");
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 462eebb..0dbe5c7 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -97,6 +97,15 @@ config NFT_MASQ_IPV6
This is the expression that provides IPv4 masquerading support for
nf_tables.
+config NFT_REDIR_IPV6
+ tristate "IPv6 redirect support for nf_tables"
+ depends on NF_TABLES_IPV6
+ depends on NFT_REDIR
+ select NF_NAT_REDIRECT_IPV6
+ help
+ This is the expression that provides IPv4 redirect support for
+ nf_tables.
+
endif # NF_NAT_IPV6
config IP6_NF_IPTABLES
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index 6c2baab..d2ac9f5 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV6) += nft_chain_route_ipv6.o
obj-$(CONFIG_NFT_CHAIN_NAT_IPV6) += nft_chain_nat_ipv6.o
obj-$(CONFIG_NFT_REJECT_IPV6) += nft_reject_ipv6.o
obj-$(CONFIG_NFT_MASQ_IPV6) += nft_masq_ipv6.o
+obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redir_ipv6.o
# matches
obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
diff --git a/net/ipv6/netfilter/nft_redir_ipv6.c b/net/ipv6/netfilter/nft_redir_ipv6.c
new file mode 100644
index 0000000..83420ee
--- /dev/null
+++ b/net/ipv6/netfilter/nft_redir_ipv6.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
+ *
+ * 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/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nft_redir.h>
+#include <net/netfilter/ipv6/nf_nat_redirect.h>
+
+static void nft_redir_ipv6_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_redir *priv = nft_expr_priv(expr);
+ struct nf_nat_range range;
+ unsigned int verdict;
+
+ memset(&range, 0, sizeof(range));
+ if (priv->sreg_proto_min) {
+ range.min_proto.all = (__force __be16)
+ data[priv->sreg_proto_min].data[0];
+ range.max_proto.all = (__force __be16)
+ data[priv->sreg_proto_max].data[0];
+ range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+ }
+
+ range.flags |= priv->flags;
+
+ verdict = nf_nat_redirect_ipv6(pkt->skb, &range, pkt->ops->hooknum);
+ data[NFT_REG_VERDICT].verdict = verdict;
+}
+
+static struct nft_expr_type nft_redir_ipv6_type;
+static const struct nft_expr_ops nft_redir_ipv6_ops = {
+ .type = &nft_redir_ipv6_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_redir)),
+ .eval = nft_redir_ipv6_eval,
+ .init = nft_redir_init,
+ .dump = nft_redir_dump,
+ .validate = nft_redir_validate,
+};
+
+static struct nft_expr_type nft_redir_ipv6_type __read_mostly = {
+ .family = NFPROTO_IPV6,
+ .name = "redir",
+ .ops = &nft_redir_ipv6_ops,
+ .policy = nft_redir_policy,
+ .maxattr = NFTA_REDIR_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_redir_ipv6_module_init(void)
+{
+ return nft_register_expr(&nft_redir_ipv6_type);
+}
+
+static void __exit nft_redir_ipv6_module_exit(void)
+{
+ nft_unregister_expr(&nft_redir_ipv6_type);
+}
+
+module_init(nft_redir_ipv6_module_init);
+module_exit(nft_redir_ipv6_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "redir");
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 49deb4e..373486a 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -505,6 +505,15 @@ config NFT_MASQ
This option adds the "masquerade" expression that you can use
to perform NAT in the masquerade flavour.
+config NFT_REDIR
+ depends on NF_TABLES
+ depends on NF_CONNTRACK
+ depends on NF_NAT
+ tristate "Netfilter nf_tables redirect support"
+ help
+ This options adds the "redirect" expression that you can use
+ to perform NAT in the redirect flavour.
+
config NFT_NAT
depends on NF_TABLES
depends on NF_CONNTRACK
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index a9571be..f3eb468 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_NFT_HASH) += nft_hash.o
obj-$(CONFIG_NFT_COUNTER) += nft_counter.o
obj-$(CONFIG_NFT_LOG) += nft_log.o
obj-$(CONFIG_NFT_MASQ) += nft_masq.o
+obj-$(CONFIG_NFT_REDIR) += nft_redir.o
# generic X tables
obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
diff --git a/net/netfilter/nft_redir.c b/net/netfilter/nft_redir.c
new file mode 100644
index 0000000..e27b4e3
--- /dev/null
+++ b/net/netfilter/nft_redir.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
+ *
+ * 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/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nft_redir.h>
+
+const struct nla_policy nft_redir_policy[NFTA_REDIR_MAX + 1] = {
+ [NFTA_REDIR_REG_PROTO_MIN] = { .type = NLA_U32 },
+ [NFTA_REDIR_REG_PROTO_MAX] = { .type = NLA_U32 },
+ [NFTA_REDIR_FLAGS] = { .type = NLA_U32 },
+};
+EXPORT_SYMBOL_GPL(nft_redir_policy);
+
+int nft_redir_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_redir *priv = nft_expr_priv(expr);
+ u32 nla_be32;
+ int err;
+
+ err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
+ nla_be32 = nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MIN]);
+ priv->sreg_proto_min = ntohl(nla_be32);
+ err = nft_validate_input_register(priv->sreg_proto_min);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
+ nla_be32 = nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MAX]);
+ priv->sreg_proto_max = ntohl(nla_be32);
+ err = nft_validate_input_register(priv->sreg_proto_max);
+ if (err < 0)
+ return err;
+ } else {
+ priv->sreg_proto_max = priv->sreg_proto_min;
+ }
+ }
+
+ if (tb[NFTA_REDIR_FLAGS]) {
+ priv->flags = ntohl(nla_get_be32(tb[NFTA_REDIR_FLAGS]));
+ if (priv->flags & ~NF_NAT_RANGE_MASK)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nft_redir_init);
+
+int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_redir *priv = nft_expr_priv(expr);
+
+ if (priv->sreg_proto_min) {
+ if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MIN,
+ htonl(priv->sreg_proto_min)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MAX,
+ htonl(priv->sreg_proto_max)))
+ goto nla_put_failure;
+ }
+
+ if (priv->flags != 0 &&
+ nla_put_be32(skb, NFTA_REDIR_FLAGS, htonl(priv->flags)))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+EXPORT_SYMBOL_GPL(nft_redir_dump);
+
+int nft_redir_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nft_data **data)
+{
+ return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+}
+EXPORT_SYMBOL_GPL(nft_redir_validate);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>");
--
1.7.10.4
--
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