netfilter: nf_nat: export NAT definitions to userspace

Export the NAT definitions to userspace. So far userspace (specifically,
iptables) has been copying the headers files from include/net. Also
rename some structures and definitions in preparation for IPv6 NAT.
Since these have never been officially exported, this doesn't affect
existing userspace code.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netfilter/Kbuild

@@ -5,6 +5,7 @@ header-y += nf_conntrack_ftp.h
 header-y += nf_conntrack_sctp.h
 header-y += nf_conntrack_tcp.h
 header-y += nf_conntrack_tuple_common.h
+header-y += nf_nat.h
 header-y += nfnetlink.h
 header-y += nfnetlink_compat.h
 header-y += nfnetlink_conntrack.h

include/linux/netfilter/nf_conntrack_tuple_common.h

@@ -7,6 +7,33 @@ enum ip_conntrack_dir {
 	IP_CT_DIR_MAX
 };
 
+/* The protocol-specific manipulable parts of the tuple: always in
+ * network order
+ */
+union nf_conntrack_man_proto {
+	/* Add other protocols here. */
+	__be16 all;
+
+	struct {
+		__be16 port;
+	} tcp;
+	struct {
+		__be16 port;
+	} udp;
+	struct {
+		__be16 id;
+	} icmp;
+	struct {
+		__be16 port;
+	} dccp;
+	struct {
+		__be16 port;
+	} sctp;
+	struct {
+		__be16 key;	/* GRE key is 32bit, PPtP only uses 16bit */
+	} gre;
+};
+
 #define CTINFO2DIR(ctinfo) ((ctinfo) >= IP_CT_IS_REPLY ? IP_CT_DIR_REPLY : IP_CT_DIR_ORIGINAL)
 
 #endif /* _NF_CONNTRACK_TUPLE_COMMON_H */

include/linux/netfilter/nf_nat.h

@@ -0,0 +1,25 @@
+#ifndef _NETFILTER_NF_NAT_H
+#define _NETFILTER_NF_NAT_H
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_conntrack_tuple_common.h>
+
+#define NF_NAT_RANGE_MAP_IPS		1
+#define NF_NAT_RANGE_PROTO_SPECIFIED	2
+#define NF_NAT_RANGE_PROTO_RANDOM	4
+#define NF_NAT_RANGE_PERSISTENT		8
+
+struct nf_nat_ipv4_range {
+	unsigned int			flags;
+	__be32				min_ip;
+	__be32				max_ip;
+	union nf_conntrack_man_proto	min;
+	union nf_conntrack_man_proto	max;
+};
+
+struct nf_nat_ipv4_multi_range_compat {
+	unsigned int			rangesize;
+	struct nf_nat_ipv4_range	range[1];
+};
+
+#endif /* _NETFILTER_NF_NAT_H */

include/linux/netfilter_ipv4/Kbuild

@@ -12,4 +12,3 @@ header-y += ipt_ah.h
 header-y += ipt_ecn.h
 header-y += ipt_realm.h
 header-y += ipt_ttl.h
-header-y += nf_nat.h

include/net/netfilter/nf_conntrack_tuple.h

@@ -12,7 +12,6 @@
 
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter/nf_conntrack_tuple_common.h>
-#include <linux/netfilter_ipv4/nf_nat.h>
 #include <linux/list_nulls.h>
 
 /* A `tuple' is a structure containing the information to uniquely

include/net/netfilter/nf_nat.h

@@ -1,14 +1,12 @@
 #ifndef _NF_NAT_H
 #define _NF_NAT_H
 #include <linux/netfilter_ipv4.h>
-#include <linux/netfilter_ipv4/nf_nat.h>
+#include <linux/netfilter/nf_nat.h>
 #include <net/netfilter/nf_conntrack_tuple.h>
 
-#define NF_NAT_MAPPING_TYPE_MAX_NAMELEN 16
-
 enum nf_nat_manip_type {
-	IP_NAT_MANIP_SRC,
-	IP_NAT_MANIP_DST
+	NF_NAT_MANIP_SRC,
+	NF_NAT_MANIP_DST
 };
 
 /* SRC manip occurs POST_ROUTING or LOCAL_IN */
@@ -52,7 +50,7 @@ struct nf_conn_nat {
 
 /* Set up the info structure to map into this range. */
 extern unsigned int nf_nat_setup_info(struct nf_conn *ct,
-				      const struct nf_nat_range *range,
+				      const struct nf_nat_ipv4_range *range,
 				      enum nf_nat_manip_type maniptype);
 
 /* Is this tuple already taken? (not by us)*/

include/net/netfilter/nf_nat_core.h

@@ -20,7 +20,7 @@ extern int nf_nat_icmp_reply_translation(struct nf_conn *ct,
 static inline int nf_nat_initialized(struct nf_conn *ct,
 				     enum nf_nat_manip_type manip)
 {
-	if (manip == IP_NAT_MANIP_SRC)
+	if (manip == NF_NAT_MANIP_SRC)
 		return ct->status & IPS_SRC_NAT_DONE;
 	else
 		return ct->status & IPS_DST_NAT_DONE;

include/net/netfilter/nf_nat_protocol.h

@@ -4,7 +4,7 @@
 #include <net/netfilter/nf_nat.h>
 #include <linux/netfilter/nfnetlink_conntrack.h>
 
-struct nf_nat_range;
+struct nf_nat_ipv4_range;
 
 struct nf_nat_protocol {
 	/* Protocol number. */
@@ -30,15 +30,15 @@ struct nf_nat_protocol {
 	   possible.  Per-protocol part of tuple is initialized to the
 	   incoming packet. */
 	void (*unique_tuple)(struct nf_conntrack_tuple *tuple,
-			     const struct nf_nat_range *range,
+			     const struct nf_nat_ipv4_range *range,
 			     enum nf_nat_manip_type maniptype,
 			     const struct nf_conn *ct);
 
 	int (*range_to_nlattr)(struct sk_buff *skb,
-			       const struct nf_nat_range *range);
+			       const struct nf_nat_ipv4_range *range);
 
 	int (*nlattr_to_range)(struct nlattr *tb[],
-			       struct nf_nat_range *range);
+			       struct nf_nat_ipv4_range *range);
 };
 
 /* Protocol registration. */
@@ -61,14 +61,14 @@ extern bool nf_nat_proto_in_range(const struct nf_conntrack_tuple *tuple,
 				  const union nf_conntrack_man_proto *max);
 
 extern void nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,
-				      const struct nf_nat_range *range,
+				      const struct nf_nat_ipv4_range *range,
 				      enum nf_nat_manip_type maniptype,
 				      const struct nf_conn *ct,
 				      u_int16_t *rover);
 
 extern int nf_nat_proto_range_to_nlattr(struct sk_buff *skb,
-					const struct nf_nat_range *range);
+					const struct nf_nat_ipv4_range *range);
 extern int nf_nat_proto_nlattr_to_range(struct nlattr *tb[],
-					struct nf_nat_range *range);
+					struct nf_nat_ipv4_range *range);
 
 #endif /*_NF_NAT_PROTO_H*/

net/ipv4/netfilter/ipt_MASQUERADE.c

@@ -30,9 +30,9 @@ MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
 /* FIXME: Multiple targets. --RR */
 static int masquerade_tg_check(const struct xt_tgchk_param *par)
 {
-	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
 
-	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
 		pr_debug("bad MAP_IPS.\n");
 		return -EINVAL;
 	}
@@ -49,8 +49,8 @@ masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	struct nf_conn *ct;
 	struct nf_conn_nat *nat;
 	enum ip_conntrack_info ctinfo;
-	struct nf_nat_range newrange;
-	const struct nf_nat_multi_range_compat *mr;
+	struct nf_nat_ipv4_range newrange;
+	const struct nf_nat_ipv4_multi_range_compat *mr;
 	const struct rtable *rt;
 	__be32 newsrc;
 
@@ -79,13 +79,13 @@ masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	nat->masq_index = par->out->ifindex;
 
 	/* Transfer from original range. */
-	newrange = ((struct nf_nat_range)
-		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+	newrange = ((struct nf_nat_ipv4_range)
+		{ mr->range[0].flags | NF_NAT_RANGE_MAP_IPS,
 		  newsrc, newsrc,
 		  mr->range[0].min, mr->range[0].max });
 
 	/* Hand modified range to generic setup. */
-	return nf_nat_setup_info(ct, &newrange, IP_NAT_MANIP_SRC);
+	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC);
 }
 
 static int
@@ -139,7 +139,7 @@ static struct xt_target masquerade_tg_reg __read_mostly = {
 	.name		= "MASQUERADE",
 	.family		= NFPROTO_IPV4,
 	.target		= masquerade_tg,
-	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
 	.table		= "nat",
 	.hooks		= 1 << NF_INET_POST_ROUTING,
 	.checkentry	= masquerade_tg_check,

net/ipv4/netfilter/ipt_NETMAP.c

@@ -24,9 +24,9 @@ MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of IPv4 subnets");
 
 static int netmap_tg_check(const struct xt_tgchk_param *par)
 {
-	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
 
-	if (!(mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)) {
+	if (!(mr->range[0].flags & NF_NAT_RANGE_MAP_IPS)) {
 		pr_debug("bad MAP_IPS.\n");
 		return -EINVAL;
 	}
@@ -43,8 +43,8 @@ netmap_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	struct nf_conn *ct;
 	enum ip_conntrack_info ctinfo;
 	__be32 new_ip, netmask;
-	const struct nf_nat_multi_range_compat *mr = par->targinfo;
-	struct nf_nat_range newrange;
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+	struct nf_nat_ipv4_range newrange;
 
 	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
 		     par->hooknum == NF_INET_POST_ROUTING ||
@@ -61,8 +61,8 @@ netmap_tg(struct sk_buff *skb, const struct xt_action_param *par)
 		new_ip = ip_hdr(skb)->saddr & ~netmask;
 	new_ip |= mr->range[0].min_ip & netmask;
 
-	newrange = ((struct nf_nat_range)
-		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+	newrange = ((struct nf_nat_ipv4_range)
+		{ mr->range[0].flags | NF_NAT_RANGE_MAP_IPS,
 		  new_ip, new_ip,
 		  mr->range[0].min, mr->range[0].max });
 
@@ -74,7 +74,7 @@ static struct xt_target netmap_tg_reg __read_mostly = {
 	.name 		= "NETMAP",
 	.family		= NFPROTO_IPV4,
 	.target 	= netmap_tg,
-	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
 	.table		= "nat",
 	.hooks		= (1 << NF_INET_PRE_ROUTING) |
 			  (1 << NF_INET_POST_ROUTING) |

net/ipv4/netfilter/ipt_REDIRECT.c

@@ -28,9 +28,9 @@ MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
 /* FIXME: Take multiple ranges --RR */
 static int redirect_tg_check(const struct xt_tgchk_param *par)
 {
-	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
 
-	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
 		pr_debug("bad MAP_IPS.\n");
 		return -EINVAL;
 	}
@@ -47,8 +47,8 @@ redirect_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	struct nf_conn *ct;
 	enum ip_conntrack_info ctinfo;
 	__be32 newdst;
-	const struct nf_nat_multi_range_compat *mr = par->targinfo;
-	struct nf_nat_range newrange;
+	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
+	struct nf_nat_ipv4_range newrange;
 
 	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
 		     par->hooknum == NF_INET_LOCAL_OUT);
@@ -76,20 +76,20 @@ redirect_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	}
 
 	/* Transfer from original range. */
-	newrange = ((struct nf_nat_range)
-		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+	newrange = ((struct nf_nat_ipv4_range)
+		{ mr->range[0].flags | NF_NAT_RANGE_MAP_IPS,
 		  newdst, newdst,
 		  mr->range[0].min, mr->range[0].max });
 
 	/* Hand modified range to generic setup. */
-	return nf_nat_setup_info(ct, &newrange, IP_NAT_MANIP_DST);
+	return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
 }
 
 static struct xt_target redirect_tg_reg __read_mostly = {
 	.name		= "REDIRECT",
 	.family		= NFPROTO_IPV4,
 	.target		= redirect_tg,
-	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
 	.table		= "nat",
 	.hooks		= (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT),
 	.checkentry	= redirect_tg_check,