netfilter: nf_tables: Add support for IPv6 NAT
This patch generalizes the NAT expression to support both IPv4 and IPv6
using the existing IPv4/IPv6 NAT infrastructure. This also adds the
NAT chain type for IPv6.
This patch collapses the following patches that were posted to the
netfilter-devel mailing list, from Tomasz:
* nf_tables: Change NFTA_NAT_ attributes to better semantic significance
* nf_tables: Split IPv4 NAT into NAT expression and IPv4 NAT chain
* nf_tables: Add support for IPv6 NAT expression
* nf_tables: Add support for IPv6 NAT chain
* nf_tables: Fix up build issue on IPv6 NAT support
And, from Pablo Neira Ayuso:
* fix missing dependencies in nft_chain_nat
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 49e3627..48acec1 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -450,6 +450,12 @@
depends on NF_TABLES
tristate "Netfilter nf_tables limit module"
+config NFT_NAT
+ depends on NF_TABLES
+ depends on NF_CONNTRACK
+ depends on NF_NAT
+ tristate "Netfilter nf_tables nat module"
+
config NFT_COMPAT
depends on NF_TABLES
depends on NETFILTER_XTABLES
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index a678145..394483b 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -75,6 +75,7 @@
obj-$(CONFIG_NFT_META) += nft_meta.o
obj-$(CONFIG_NFT_CT) += nft_ct.o
obj-$(CONFIG_NFT_LIMIT) += nft_limit.o
+obj-$(CONFIG_NFT_NAT) += nft_nat.o
#nf_tables-objs += nft_meta_target.o
obj-$(CONFIG_NFT_RBTREE) += nft_rbtree.o
obj-$(CONFIG_NFT_HASH) += nft_hash.o
diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c
new file mode 100644
index 0000000..b0b87b2
--- /dev/null
+++ b/net/netfilter/nft_nat.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
+ * Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
+ * Copyright (c) 2012 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/string.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/ip.h>
+
+struct nft_nat {
+ enum nft_registers sreg_addr_min:8;
+ enum nft_registers sreg_addr_max:8;
+ enum nft_registers sreg_proto_min:8;
+ enum nft_registers sreg_proto_max:8;
+ int family;
+ enum nf_nat_manip_type type;
+};
+
+static void nft_nat_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_nat *priv = nft_expr_priv(expr);
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
+ struct nf_nat_range range;
+
+ memset(&range, 0, sizeof(range));
+ if (priv->sreg_addr_min) {
+ if (priv->family == AF_INET) {
+ range.min_addr.ip = data[priv->sreg_addr_min].data[0];
+ range.max_addr.ip = data[priv->sreg_addr_max].data[0];
+
+ } else {
+ memcpy(range.min_addr.ip6,
+ data[priv->sreg_addr_min].data,
+ sizeof(struct nft_data));
+ memcpy(range.max_addr.ip6,
+ data[priv->sreg_addr_max].data,
+ sizeof(struct nft_data));
+ }
+ range.flags |= NF_NAT_RANGE_MAP_IPS;
+ }
+
+ if (priv->sreg_proto_min) {
+ range.min_proto.all = data[priv->sreg_proto_min].data[0];
+ range.max_proto.all = data[priv->sreg_proto_max].data[0];
+ range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+ }
+
+ data[NFT_REG_VERDICT].verdict =
+ nf_nat_setup_info(ct, &range, priv->type);
+}
+
+static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
+ [NFTA_NAT_TYPE] = { .type = NLA_U32 },
+ [NFTA_NAT_FAMILY] = { .type = NLA_U32 },
+ [NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
+ [NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
+ [NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
+ [NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
+};
+
+static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_nat *priv = nft_expr_priv(expr);
+ int err;
+
+ if (tb[NFTA_NAT_TYPE] == NULL)
+ return -EINVAL;
+
+ switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
+ case NFT_NAT_SNAT:
+ priv->type = NF_NAT_MANIP_SRC;
+ break;
+ case NFT_NAT_DNAT:
+ priv->type = NF_NAT_MANIP_DST;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (tb[NFTA_NAT_FAMILY] == NULL)
+ return -EINVAL;
+
+ priv->family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
+ if (priv->family != AF_INET && priv->family != AF_INET6)
+ return -EINVAL;
+
+ if (tb[NFTA_NAT_REG_ADDR_MIN]) {
+ priv->sreg_addr_min = ntohl(nla_get_be32(
+ tb[NFTA_NAT_REG_ADDR_MIN]));
+ err = nft_validate_input_register(priv->sreg_addr_min);
+ if (err < 0)
+ return err;
+ }
+
+ if (tb[NFTA_NAT_REG_ADDR_MAX]) {
+ priv->sreg_addr_max = ntohl(nla_get_be32(
+ tb[NFTA_NAT_REG_ADDR_MAX]));
+ err = nft_validate_input_register(priv->sreg_addr_max);
+ if (err < 0)
+ return err;
+ } else
+ priv->sreg_addr_max = priv->sreg_addr_min;
+
+ if (tb[NFTA_NAT_REG_PROTO_MIN]) {
+ priv->sreg_proto_min = ntohl(nla_get_be32(
+ tb[NFTA_NAT_REG_PROTO_MIN]));
+ err = nft_validate_input_register(priv->sreg_proto_min);
+ if (err < 0)
+ return err;
+ }
+
+ if (tb[NFTA_NAT_REG_PROTO_MAX]) {
+ priv->sreg_proto_max = ntohl(nla_get_be32(
+ tb[NFTA_NAT_REG_PROTO_MAX]));
+ err = nft_validate_input_register(priv->sreg_proto_max);
+ if (err < 0)
+ return err;
+ } else
+ priv->sreg_proto_max = priv->sreg_proto_min;
+
+ return 0;
+}
+
+static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_nat *priv = nft_expr_priv(expr);
+
+ switch (priv->type) {
+ case NF_NAT_MANIP_SRC:
+ if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
+ goto nla_put_failure;
+ break;
+ case NF_NAT_MANIP_DST:
+ if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
+ goto nla_put_failure;
+ break;
+ }
+
+ if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb,
+ NFTA_NAT_REG_ADDR_MIN, htonl(priv->sreg_addr_min)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb,
+ NFTA_NAT_REG_ADDR_MAX, htonl(priv->sreg_addr_max)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb,
+ NFTA_NAT_REG_PROTO_MIN, htonl(priv->sreg_proto_min)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb,
+ NFTA_NAT_REG_PROTO_MAX, htonl(priv->sreg_proto_max)))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static struct nft_expr_type nft_nat_type;
+static const struct nft_expr_ops nft_nat_ops = {
+ .type = &nft_nat_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
+ .eval = nft_nat_eval,
+ .init = nft_nat_init,
+ .dump = nft_nat_dump,
+};
+
+static struct nft_expr_type nft_nat_type __read_mostly = {
+ .name = "nat",
+ .ops = &nft_nat_ops,
+ .policy = nft_nat_policy,
+ .maxattr = NFTA_NAT_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_nat_module_init(void)
+{
+ int err;
+
+ err = nft_register_expr(&nft_nat_type);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static void __exit nft_nat_module_exit(void)
+{
+ nft_unregister_expr(&nft_nat_type);
+}
+
+module_init(nft_nat_module_init);
+module_exit(nft_nat_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
+MODULE_ALIAS_NFT_EXPR("nat");
