From: Tomasz Bursztyka <tomasz.bursztyka@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/uapi/linux/netfilter/nf_tables.h | 18 +--
net/ipv4/netfilter/Kconfig | 1 +
net/ipv4/netfilter/nft_chain_nat_ipv4.c | 156 +--------------------
net/ipv6/netfilter/Kconfig | 5 +
net/ipv6/netfilter/Makefile | 1 +
net/ipv6/netfilter/nft_chain_nat_ipv6.c | 211 ++++++++++++++++++++++++++++
net/netfilter/Kconfig | 6 +
net/netfilter/Makefile | 1 +
net/netfilter/nft_nat.c | 220 ++++++++++++++++++++++++++++++
9 files changed, 457 insertions(+), 162 deletions(-)
create mode 100644 net/ipv6/netfilter/nft_chain_nat_ipv6.c
create mode 100644 net/netfilter/nft_nat.c
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index a9c4bce..7d4a199 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -695,18 +695,20 @@ enum nft_nat_types {
* enum nft_nat_attributes - nf_tables nat expression netlink attributes
*
* @NFTA_NAT_TYPE: NAT type (NLA_U32: nft_nat_types)
- * @NFTA_NAT_ADDR_MIN: source register of address range start (NLA_U32: nft_registers)
- * @NFTA_NAT_ADDR_MAX: source register of address range end (NLA_U32: nft_registers)
- * @NFTA_NAT_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers)
- * @NFTA_NAT_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers)
+ * @NFTA_NAT_FAMILY: NAT family (NLA_U32)
+ * @NFTA_NAT_REG_ADDR_MIN: source register of address range start (NLA_U32: nft_registers)
+ * @NFTA_NAT_REG_ADDR_MAX: source register of address range end (NLA_U32: nft_registers)
+ * @NFTA_NAT_REG_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers)
+ * @NFTA_NAT_REG_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers)
*/
enum nft_nat_attributes {
NFTA_NAT_UNSPEC,
NFTA_NAT_TYPE,
- NFTA_NAT_ADDR_MIN,
- NFTA_NAT_ADDR_MAX,
- NFTA_NAT_PROTO_MIN,
- NFTA_NAT_PROTO_MAX,
+ NFTA_NAT_FAMILY,
+ NFTA_NAT_REG_ADDR_MIN,
+ NFTA_NAT_REG_ADDR_MAX,
+ NFTA_NAT_REG_PROTO_MIN,
+ NFTA_NAT_REG_PROTO_MAX,
__NFTA_NAT_MAX
};
#define NFTA_NAT_MAX (__NFTA_NAT_MAX - 1)
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index ae65fe9..1f37ef6 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -50,6 +50,7 @@ config NFT_CHAIN_ROUTE_IPV4
config NFT_CHAIN_NAT_IPV4
depends on NF_TABLES_IPV4
+ depends on NF_NAT_IPV4 && NFT_NAT
tristate "IPv4 nf_tables nat chain support"
config IP_NF_IPTABLES
diff --git a/net/ipv4/netfilter/nft_chain_nat_ipv4.c b/net/ipv4/netfilter/nft_chain_nat_ipv4.c
index e09c201..cf2c792 100644
--- a/net/ipv4/netfilter/nft_chain_nat_ipv4.c
+++ b/net/ipv4/netfilter/nft_chain_nat_ipv4.c
@@ -1,6 +1,7 @@
/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@xxxxxxxxx>
* Copyright (c) 2012 Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ * Copyright (c) 2012 Intel Corporation
*
* 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
@@ -14,10 +15,8 @@
#include <linux/list.h>
#include <linux/skbuff.h>
#include <linux/ip.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>
@@ -27,147 +26,6 @@
#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;
- 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) {
- range.min_addr.ip = data[priv->sreg_addr_min].data[0];
- range.max_addr.ip = data[priv->sreg_addr_max].data[0];
- 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_ADDR_MIN] = { .type = NLA_U32 },
- [NFTA_NAT_ADDR_MAX] = { .type = NLA_U32 },
- [NFTA_NAT_PROTO_MIN] = { .type = NLA_U32 },
- [NFTA_NAT_PROTO_MAX] = { .type = NLA_U32 },
- [NFTA_NAT_TYPE] = { .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_ADDR_MIN]) {
- priv->sreg_addr_min = ntohl(nla_get_be32(tb[NFTA_NAT_ADDR_MIN]));
- err = nft_validate_input_register(priv->sreg_addr_min);
- if (err < 0)
- return err;
- }
-
- if (tb[NFTA_NAT_ADDR_MAX]) {
- priv->sreg_addr_max = ntohl(nla_get_be32(tb[NFTA_NAT_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_PROTO_MIN]) {
- priv->sreg_proto_min = ntohl(nla_get_be32(tb[NFTA_NAT_PROTO_MIN]));
- err = nft_validate_input_register(priv->sreg_proto_min);
- if (err < 0)
- return err;
- }
-
- if (tb[NFTA_NAT_PROTO_MAX]) {
- priv->sreg_proto_max = ntohl(nla_get_be32(tb[NFTA_NAT_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_ADDR_MIN, htonl(priv->sreg_addr_min)))
- goto nla_put_failure;
- if (nla_put_be32(skb, NFTA_NAT_ADDR_MAX, htonl(priv->sreg_addr_max)))
- goto nla_put_failure;
- if (nla_put_be32(skb, NFTA_NAT_PROTO_MIN, htonl(priv->sreg_proto_min)))
- goto nla_put_failure;
- if (nla_put_be32(skb, NFTA_NAT_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,
-};
-
/*
* NAT chains
*/
@@ -306,7 +164,7 @@ static unsigned int nf_nat_output(const struct nf_hook_ops *ops,
return ret;
}
-struct nf_chain_type nft_chain_nat_ipv4 = {
+static struct nf_chain_type nft_chain_nat_ipv4 = {
.family = NFPROTO_IPV4,
.name = "nat",
.type = NFT_CHAIN_T_NAT,
@@ -331,20 +189,11 @@ static int __init nft_chain_nat_init(void)
if (err < 0)
return err;
- err = nft_register_expr(&nft_nat_type);
- if (err < 0)
- goto err;
-
return 0;
-
-err:
- nft_unregister_chain_type(&nft_chain_nat_ipv4);
- return err;
}
static void __exit nft_chain_nat_exit(void)
{
- nft_unregister_expr(&nft_nat_type);
nft_unregister_chain_type(&nft_chain_nat_ipv4);
}
@@ -354,4 +203,3 @@ module_exit(nft_chain_nat_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@xxxxxxxxx>");
MODULE_ALIAS_NFT_CHAIN(AF_INET, "nat");
-MODULE_ALIAS_NFT_EXPR("nat");
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 2383306..7702f9e 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -33,6 +33,11 @@ config NFT_CHAIN_ROUTE_IPV6
depends on NF_TABLES_IPV6
tristate "IPv6 nf_tables route chain support"
+config NFT_CHAIN_NAT_IPV6
+ depends on NF_TABLES_IPV6
+ depends on NF_NAT_IPV6 && NFT_NAT
+ tristate "IPv6 nf_tables nat chain support"
+
config IP6_NF_IPTABLES
tristate "IP6 tables support (required for filtering)"
depends on INET && IPV6
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index be4913a..d1b4928 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_NF_DEFRAG_IPV6) += nf_defrag_ipv6.o
# nf_tables
obj-$(CONFIG_NF_TABLES_IPV6) += nf_tables_ipv6.o
obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV6) += nft_chain_route_ipv6.o
+obj-$(CONFIG_NFT_CHAIN_NAT_IPV6) += nft_chain_nat_ipv6.o
# matches
obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
diff --git a/net/ipv6/netfilter/nft_chain_nat_ipv6.c b/net/ipv6/netfilter/nft_chain_nat_ipv6.c
new file mode 100644
index 0000000..e86dcd7
--- /dev/null
+++ b/net/ipv6/netfilter/nft_chain_nat_ipv6.c
@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2011 Patrick McHardy <kaber@xxxxxxxxx>
+ * 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/list.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.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_tables_ipv6.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/ipv6.h>
+
+/*
+ * IPv6 NAT chains
+ */
+
+static unsigned int nf_nat_ipv6_fn(const struct nf_hook_ops *ops,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ struct nf_conn_nat *nat;
+ enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum);
+ __be16 frag_off;
+ int hdrlen;
+ u8 nexthdr;
+ struct nft_pktinfo pkt;
+ unsigned int ret;
+
+ if (ct == NULL || nf_ct_is_untracked(ct))
+ return NF_ACCEPT;
+
+ nat = nfct_nat(ct);
+ if (nat == NULL) {
+ /* Conntrack module was loaded late, can't add extension. */
+ if (nf_ct_is_confirmed(ct))
+ return NF_ACCEPT;
+ nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+ if (nat == NULL)
+ return NF_ACCEPT;
+ }
+
+ switch (ctinfo) {
+ case IP_CT_RELATED:
+ case IP_CT_RELATED + IP_CT_IS_REPLY:
+ nexthdr = ipv6_hdr(skb)->nexthdr;
+ hdrlen = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
+ &nexthdr, &frag_off);
+
+ if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
+ if (!nf_nat_icmpv6_reply_translation(skb, ct, ctinfo,
+ ops->hooknum,
+ hdrlen))
+ return NF_DROP;
+ else
+ return NF_ACCEPT;
+ }
+ /* Fall through */
+ case IP_CT_NEW:
+ if (nf_nat_initialized(ct, maniptype))
+ break;
+
+ nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out);
+
+ ret = nft_do_chain_pktinfo(&pkt, ops);
+ if (ret != NF_ACCEPT)
+ return ret;
+ if (!nf_nat_initialized(ct, maniptype)) {
+ ret = nf_nat_alloc_null_binding(ct, ops->hooknum);
+ if (ret != NF_ACCEPT)
+ return ret;
+ }
+ default:
+ break;
+ }
+
+ return nf_nat_packet(ct, ctinfo, ops->hooknum, skb);
+}
+
+static unsigned int nf_nat_ipv6_prerouting(const struct nf_hook_ops *ops,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct in6_addr daddr = ipv6_hdr(skb)->daddr;
+ unsigned int ret;
+
+ ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn);
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr))
+ skb_dst_drop(skb);
+
+ return ret;
+}
+
+static unsigned int nf_nat_ipv6_postrouting(const struct nf_hook_ops *ops,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ enum ip_conntrack_info ctinfo __maybe_unused;
+ const struct nf_conn *ct __maybe_unused;
+ unsigned int ret;
+
+ ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn);
+#ifdef CONFIG_XFRM
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ !(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
+ (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+ if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3) ||
+ (ct->tuplehash[dir].tuple.src.u.all !=
+ ct->tuplehash[!dir].tuple.dst.u.all))
+ if (nf_xfrm_me_harder(skb, AF_INET6) < 0)
+ ret = NF_DROP;
+ }
+#endif
+ return ret;
+}
+
+static unsigned int nf_nat_ipv6_output(const struct nf_hook_ops *ops,
+ struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ enum ip_conntrack_info ctinfo;
+ const struct nf_conn *ct;
+ unsigned int ret;
+
+ ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn);
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+ if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3,
+ &ct->tuplehash[!dir].tuple.src.u3)) {
+ if (ip6_route_me_harder(skb))
+ ret = NF_DROP;
+ }
+#ifdef CONFIG_XFRM
+ else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
+ ct->tuplehash[dir].tuple.dst.u.all !=
+ ct->tuplehash[!dir].tuple.src.u.all)
+ if (nf_xfrm_me_harder(skb, AF_INET6))
+ ret = NF_DROP;
+#endif
+ }
+ return ret;
+}
+
+static struct nf_chain_type nft_chain_nat_ipv6 = {
+ .family = NFPROTO_IPV6,
+ .name = "nat",
+ .type = NFT_CHAIN_T_NAT,
+ .hook_mask = (1 << NF_INET_PRE_ROUTING) |
+ (1 << NF_INET_POST_ROUTING) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_LOCAL_IN),
+ .fn = {
+ [NF_INET_PRE_ROUTING] = nf_nat_ipv6_prerouting,
+ [NF_INET_POST_ROUTING] = nf_nat_ipv6_postrouting,
+ [NF_INET_LOCAL_OUT] = nf_nat_ipv6_output,
+ [NF_INET_LOCAL_IN] = nf_nat_ipv6_fn,
+ },
+ .me = THIS_MODULE,
+};
+
+static int __init nft_chain_nat_ipv6_init(void)
+{
+ int err;
+
+ err = nft_register_chain_type(&nft_chain_nat_ipv6);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static void __exit nft_chain_nat_ipv6_exit(void)
+{
+ nft_unregister_chain_type(&nft_chain_nat_ipv6);
+}
+
+module_init(nft_chain_nat_ipv6_init);
+module_exit(nft_chain_nat_ipv6_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@xxxxxxxxxxxxxxx>");
+MODULE_ALIAS_NFT_CHAIN(AF_INET6, "nat");
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 @@ config NFT_LIMIT
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_EXTHDR) += nft_exthdr.o
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@xxxxxxxxx>
+ * Copyright (c) 2012 Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ * 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@xxxxxxxxxxxxxxx>");
+MODULE_ALIAS_NFT_EXPR("nat");
--
1.7.10.4
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