static inline void
nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family)
{
-#ifdef CONFIG_IP_NF_NAT_NEEDED
+#if defined(CONFIG_IP_NF_NAT_NEEDED) || defined(CONFIG_NF_NAT_NEEDED)
void (*decodefn)(struct sk_buff *, struct flowi *);
if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL)
#ifndef _NF_CONNTRACK_IPV4_H
#define _NF_CONNTRACK_IPV4_H
-#ifdef CONFIG_IP_NF_NAT_NEEDED
-#include <linux/netfilter_ipv4/ip_nat.h>
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat.h>
/* per conntrack: nat application helper private data */
-union ip_conntrack_nat_help {
+union nf_conntrack_nat_help {
/* insert nat helper private data here */
};
-struct nf_conntrack_ipv4_nat {
- struct ip_nat_info info;
- union ip_conntrack_nat_help help;
+struct nf_conn_nat {
+ struct nf_nat_info info;
+ union nf_conntrack_nat_help help;
#if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
int masq_index;
#endif
};
-#endif /* CONFIG_IP_NF_NAT_NEEDED */
-
-struct nf_conntrack_ipv4 {
-#ifdef CONFIG_IP_NF_NAT_NEEDED
- struct nf_conntrack_ipv4_nat *nat;
-#endif
-};
+#endif /* CONFIG_NF_NAT_NEEDED */
/* Returns new sk_buff, or NULL */
struct sk_buff *
/* valid combinations:
* basic: nf_conn, nf_conn .. nf_conn_help
- * nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat, nf_conn help
+ * nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat .. nf_conn help
*/
+#ifdef CONFIG_NF_NAT_NEEDED
+static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
+{
+ unsigned int offset = sizeof(struct nf_conn);
+
+ if (!(ct->features & NF_CT_F_NAT))
+ return NULL;
+
+ offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
+ return (struct nf_conn_nat *) ((void *)ct + offset);
+}
+
static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{
unsigned int offset = sizeof(struct nf_conn);
if (!(ct->features & NF_CT_F_HELP))
return NULL;
+ if (ct->features & NF_CT_F_NAT) {
+ offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
+ offset += sizeof(struct nf_conn_nat);
+ }
offset = ALIGN(offset, __alignof__(struct nf_conn_help));
return (struct nf_conn_help *) ((void *)ct + offset);
}
+#else /* No NAT */
+static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
+{
+ unsigned int offset = sizeof(struct nf_conn);
+
+ if (!(ct->features & NF_CT_F_HELP))
+ return NULL;
+ offset = ALIGN(offset, __alignof__(struct nf_conn_help));
+ return (struct nf_conn_help *) ((void *)ct + offset);
+}
+#endif /* CONFIG_NF_NAT_NEEDED */
#endif /* __KERNEL__ */
#endif /* _NF_CONNTRACK_H */
#ifdef CONFIG_NF_NAT_NEEDED
/* This is the original per-proto part, used to map the
* expected connection the way the recipient expects. */
- union nf_conntrack_manip_proto saved_proto;
+ union nf_conntrack_man_proto saved_proto;
/* Direction relative to the master connection. */
enum ip_conntrack_dir dir;
#endif
--- /dev/null
+#ifndef _NF_NAT_H
+#define _NF_NAT_H
+#include <linux/netfilter_ipv4.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
+};
+
+/* SRC manip occurs POST_ROUTING or LOCAL_IN */
+#define HOOK2MANIP(hooknum) ((hooknum) != NF_IP_POST_ROUTING && (hooknum) != NF_IP_LOCAL_IN)
+
+#define IP_NAT_RANGE_MAP_IPS 1
+#define IP_NAT_RANGE_PROTO_SPECIFIED 2
+
+/* NAT sequence number modifications */
+struct nf_nat_seq {
+ /* position of the last TCP sequence number modification (if any) */
+ u_int32_t correction_pos;
+
+ /* sequence number offset before and after last modification */
+ int16_t offset_before, offset_after;
+};
+
+/* Single range specification. */
+struct nf_nat_range
+{
+ /* Set to OR of flags above. */
+ unsigned int flags;
+
+ /* Inclusive: network order. */
+ __be32 min_ip, max_ip;
+
+ /* Inclusive: network order */
+ union nf_conntrack_man_proto min, max;
+};
+
+/* For backwards compat: don't use in modern code. */
+struct nf_nat_multi_range_compat
+{
+ unsigned int rangesize; /* Must be 1. */
+
+ /* hangs off end. */
+ struct nf_nat_range range[1];
+};
+
+#ifdef __KERNEL__
+#include <linux/list.h>
+
+/* The structure embedded in the conntrack structure. */
+struct nf_nat_info
+{
+ struct list_head bysource;
+ struct nf_nat_seq seq[IP_CT_DIR_MAX];
+};
+
+struct nf_conn;
+
+/* 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,
+ unsigned int hooknum);
+
+/* Is this tuple already taken? (not by us)*/
+extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
+ const struct nf_conn *ignored_conntrack);
+
+extern int nf_nat_module_is_loaded;
+
+#else /* !__KERNEL__: iptables wants this to compile. */
+#define nf_nat_multi_range nf_nat_multi_range_compat
+#endif /*__KERNEL__*/
+#endif
--- /dev/null
+#ifndef _NF_NAT_CORE_H
+#define _NF_NAT_CORE_H
+#include <linux/list.h>
+#include <net/netfilter/nf_conntrack.h>
+
+/* This header used to share core functionality between the standalone
+ NAT module, and the compatibility layer's use of NAT for masquerading. */
+
+extern unsigned int nf_nat_packet(struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff **pskb);
+
+extern int nf_nat_icmp_reply_translation(struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff **pskb);
+
+static inline int nf_nat_initialized(struct nf_conn *ct,
+ enum nf_nat_manip_type manip)
+{
+ if (manip == IP_NAT_MANIP_SRC)
+ return test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status);
+ else
+ return test_bit(IPS_DST_NAT_DONE_BIT, &ct->status);
+}
+#endif /* _NF_NAT_CORE_H */
--- /dev/null
+#ifndef _NF_NAT_HELPER_H
+#define _NF_NAT_HELPER_H
+/* NAT protocol helper routines. */
+
+#include <net/netfilter/nf_conntrack.h>
+
+struct sk_buff;
+
+/* These return true or false. */
+extern int nf_nat_mangle_tcp_packet(struct sk_buff **skb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int match_offset,
+ unsigned int match_len,
+ const char *rep_buffer,
+ unsigned int rep_len);
+extern int nf_nat_mangle_udp_packet(struct sk_buff **skb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int match_offset,
+ unsigned int match_len,
+ const char *rep_buffer,
+ unsigned int rep_len);
+extern int nf_nat_seq_adjust(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo);
+
+/* Setup NAT on this expected conntrack so it follows master, but goes
+ * to port ct->master->saved_proto. */
+extern void nf_nat_follow_master(struct nf_conn *ct,
+ struct nf_conntrack_expect *this);
+#endif
--- /dev/null
+/* Header for use in defining a given protocol. */
+#ifndef _NF_NAT_PROTOCOL_H
+#define _NF_NAT_PROTOCOL_H
+#include <net/netfilter/nf_nat.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+struct nf_nat_range;
+
+struct nf_nat_protocol
+{
+ /* Protocol name */
+ const char *name;
+
+ /* Protocol number. */
+ unsigned int protonum;
+
+ struct module *me;
+
+ /* Translate a packet to the target according to manip type.
+ Return true if succeeded. */
+ int (*manip_pkt)(struct sk_buff **pskb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype);
+
+ /* Is the manipable part of the tuple between min and max incl? */
+ int (*in_range)(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max);
+
+ /* Alter the per-proto part of the tuple (depending on
+ maniptype), to give a unique tuple in the given range if
+ possible; return false if not. Per-protocol part of tuple
+ is initialized to the incoming packet. */
+ int (*unique_tuple)(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct);
+
+ int (*range_to_nfattr)(struct sk_buff *skb,
+ const struct nf_nat_range *range);
+
+ int (*nfattr_to_range)(struct nfattr *tb[],
+ struct nf_nat_range *range);
+};
+
+/* Protocol registration. */
+extern int nf_nat_protocol_register(struct nf_nat_protocol *proto);
+extern void nf_nat_protocol_unregister(struct nf_nat_protocol *proto);
+
+extern struct nf_nat_protocol *nf_nat_proto_find_get(u_int8_t protocol);
+extern void nf_nat_proto_put(struct nf_nat_protocol *proto);
+
+/* Built-in protocols. */
+extern struct nf_nat_protocol nf_nat_protocol_tcp;
+extern struct nf_nat_protocol nf_nat_protocol_udp;
+extern struct nf_nat_protocol nf_nat_protocol_icmp;
+extern struct nf_nat_protocol nf_nat_unknown_protocol;
+
+extern int init_protocols(void) __init;
+extern void cleanup_protocols(void);
+extern struct nf_nat_protocol *find_nat_proto(u_int16_t protonum);
+
+extern int nf_nat_port_range_to_nfattr(struct sk_buff *skb,
+ const struct nf_nat_range *range);
+extern int nf_nat_port_nfattr_to_range(struct nfattr *tb[],
+ struct nf_nat_range *range);
+
+#endif /*_NF_NAT_PROTO_H*/
--- /dev/null
+#ifndef _NF_NAT_RULE_H
+#define _NF_NAT_RULE_H
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_nat.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+/* Compatibility definitions for ipt_FOO modules */
+#define ip_nat_range nf_nat_range
+#define ip_conntrack_tuple nf_conntrack_tuple
+#define ip_conntrack_get nf_ct_get
+#define ip_conntrack nf_conn
+#define ip_nat_setup_info nf_nat_setup_info
+#define ip_nat_multi_range_compat nf_nat_multi_range_compat
+#define ip_ct_iterate_cleanup nf_ct_iterate_cleanup
+#define IP_NF_ASSERT NF_CT_ASSERT
+
+extern int nf_nat_rule_init(void) __init;
+extern void nf_nat_rule_cleanup(void);
+extern int nf_nat_rule_find(struct sk_buff **pskb,
+ unsigned int hooknum,
+ const struct net_device *in,
+ const struct net_device *out,
+ struct nf_conn *ct,
+ struct nf_nat_info *info);
+
+extern unsigned int
+alloc_null_binding(struct nf_conn *ct,
+ struct nf_nat_info *info,
+ unsigned int hooknum);
+
+extern unsigned int
+alloc_null_binding_confirmed(struct nf_conn *ct,
+ struct nf_nat_info *info,
+ unsigned int hooknum);
+#endif /* _NF_NAT_RULE_H */
depends on INET && NETFILTER
config NF_CONNTRACK_IPV4
- tristate "IPv4 support for new connection tracking (EXPERIMENTAL)"
+ tristate "IPv4 support for new connection tracking (required for NAT) (EXPERIMENTAL)"
depends on EXPERIMENTAL && NF_CONNTRACK
---help---
Connection tracking keeps a record of what packets have passed
To compile it as a module, choose M here. If unsure, say N.
-# NAT + specific targets
+# NAT + specific targets: ip_conntrack
config IP_NF_NAT
tristate "Full NAT"
depends on IP_NF_IPTABLES && IP_NF_CONNTRACK
To compile it as a module, choose M here. If unsure, say N.
+# NAT + specific targets: nf_conntrack
+config NF_NAT
+ tristate "Full NAT"
+ depends on IP_NF_IPTABLES && NF_CONNTRACK
+ help
+ The Full NAT option allows masquerading, port forwarding and other
+ forms of full Network Address Port Translation. It is controlled by
+ the `nat' table in iptables: see the man page for iptables(8).
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config IP_NF_NAT_NEEDED
bool
- depends on IP_NF_NAT != n
+ depends on IP_NF_NAT
+ default y
+
+config NF_NAT_NEEDED
+ bool
+ depends on NF_NAT
default y
config IP_NF_TARGET_MASQUERADE
tristate "MASQUERADE target support"
- depends on IP_NF_NAT
+ depends on (NF_NAT || IP_NF_NAT)
help
Masquerading is a special case of NAT: all outgoing connections are
changed to seem to come from a particular interface's address, and
config IP_NF_TARGET_REDIRECT
tristate "REDIRECT target support"
- depends on IP_NF_NAT
+ depends on (NF_NAT || IP_NF_NAT)
help
REDIRECT is a special case of NAT: all incoming connections are
mapped onto the incoming interface's address, causing the packets to
config IP_NF_TARGET_NETMAP
tristate "NETMAP target support"
- depends on IP_NF_NAT
+ depends on (NF_NAT || IP_NF_NAT)
help
NETMAP is an implementation of static 1:1 NAT mapping of network
addresses. It maps the network address part, while keeping the host
config IP_NF_TARGET_SAME
tristate "SAME target support"
- depends on IP_NF_NAT
+ depends on (NF_NAT || IP_NF_NAT)
help
This option adds a `SAME' target, which works like the standard SNAT
target, but attempts to give clients the same IP for all connections.
# objects for the standalone - connection tracking / NAT
ip_conntrack-objs := ip_conntrack_standalone.o ip_conntrack_core.o ip_conntrack_proto_generic.o ip_conntrack_proto_tcp.o ip_conntrack_proto_udp.o ip_conntrack_proto_icmp.o
ip_nat-objs := ip_nat_core.o ip_nat_helper.o ip_nat_proto_unknown.o ip_nat_proto_tcp.o ip_nat_proto_udp.o ip_nat_proto_icmp.o
+nf_nat-objs := nf_nat_core.o nf_nat_helper.o nf_nat_proto_unknown.o nf_nat_proto_tcp.o nf_nat_proto_udp.o nf_nat_proto_icmp.o
+ifneq ($(CONFIG_NF_NAT),)
+iptable_nat-objs := nf_nat_rule.o nf_nat_standalone.o
+else
iptable_nat-objs := ip_nat_rule.o ip_nat_standalone.o
+endif
ip_conntrack_pptp-objs := ip_conntrack_helper_pptp.o ip_conntrack_proto_gre.o
ip_nat_pptp-objs := ip_nat_helper_pptp.o ip_nat_proto_gre.o
# connection tracking
obj-$(CONFIG_IP_NF_CONNTRACK) += ip_conntrack.o
obj-$(CONFIG_IP_NF_NAT) += ip_nat.o
+obj-$(CONFIG_NF_NAT) += nf_nat.o
# conntrack netlink interface
obj-$(CONFIG_IP_NF_CONNTRACK_NETLINK) += ip_conntrack_netlink.o
obj-$(CONFIG_IP_NF_FILTER) += iptable_filter.o
obj-$(CONFIG_IP_NF_MANGLE) += iptable_mangle.o
obj-$(CONFIG_IP_NF_NAT) += iptable_nat.o
+obj-$(CONFIG_NF_NAT) += iptable_nat.o
obj-$(CONFIG_IP_NF_RAW) += iptable_raw.o
# matches
#define DEBUGP(format, args...)
#endif
-#define HOOKNAME(hooknum) ((hooknum) == NF_IP_POST_ROUTING ? "POST_ROUTING" \
- : ((hooknum) == NF_IP_PRE_ROUTING ? "PRE_ROUTING" \
- : ((hooknum) == NF_IP_LOCAL_OUT ? "LOCAL_OUT" \
- : ((hooknum) == NF_IP_LOCAL_IN ? "LOCAL_IN" \
- : "*ERROR*")))
-
#ifdef CONFIG_XFRM
static void nat_decode_session(struct sk_buff *skb, struct flowi *fl)
{
(depending on route). */
/* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
*
* 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
#include <net/checksum.h>
#include <net/route.h>
#include <linux/netfilter_ipv4.h>
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat_rule.h>
+#else
#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#endif
#include <linux/netfilter_ipv4/ip_tables.h>
MODULE_LICENSE("GPL");
const struct xt_target *target,
const void *targinfo)
{
+#ifdef CONFIG_NF_NAT_NEEDED
+ struct nf_conn_nat *nat;
+#endif
struct ip_conntrack *ct;
enum ip_conntrack_info ctinfo;
- const struct ip_nat_multi_range_compat *mr;
struct ip_nat_range newrange;
+ const struct ip_nat_multi_range_compat *mr;
struct rtable *rt;
__be32 newsrc;
IP_NF_ASSERT(hooknum == NF_IP_POST_ROUTING);
ct = ip_conntrack_get(*pskb, &ctinfo);
+#ifdef CONFIG_NF_NAT_NEEDED
+ nat = nfct_nat(ct);
+#endif
IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED
|| ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
/* Source address is 0.0.0.0 - locally generated packet that is
* probably not supposed to be masqueraded.
*/
+#ifdef CONFIG_NF_NAT_NEEDED
+ if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip == 0)
+#else
if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip == 0)
+#endif
return NF_ACCEPT;
mr = targinfo;
}
write_lock_bh(&masq_lock);
+#ifdef CONFIG_NF_NAT_NEEDED
+ nat->masq_index = out->ifindex;
+#else
ct->nat.masq_index = out->ifindex;
+#endif
write_unlock_bh(&masq_lock);
/* Transfer from original range. */
static inline int
device_cmp(struct ip_conntrack *i, void *ifindex)
{
+#ifdef CONFIG_NF_NAT_NEEDED
+ struct nf_conn_nat *nat = nfct_nat(i);
+#endif
int ret;
read_lock_bh(&masq_lock);
+#ifdef CONFIG_NF_NAT_NEEDED
+ ret = (nat->masq_index == (int)(long)ifindex);
+#else
ret = (i->nat.masq_index == (int)(long)ifindex);
+#endif
read_unlock_bh(&masq_lock);
return ret;
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat_rule.h>
+#else
#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#endif
#define MODULENAME "NETMAP"
MODULE_LICENSE("GPL");
/* Redirect. Simple mapping which alters dst to a local IP address. */
/* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
*
* 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
#include <net/protocol.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat_rule.h>
+#else
#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#endif
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
#include <net/protocol.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat_rule.h>
+#else
#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#endif
#include <linux/netfilter_ipv4/ipt_SAME.h>
MODULE_LICENSE("GPL");
Here we calculate the index in same->iparray which
holds the ipaddress we should use */
+#ifdef CONFIG_NF_NAT_NEEDED
+ tmpip = ntohl(t->src.u3.ip);
+
+ if (!(same->info & IPT_SAME_NODST))
+ tmpip += ntohl(t->dst.u3.ip);
+#else
tmpip = ntohl(t->src.ip);
if (!(same->info & IPT_SAME_NODST))
tmpip += ntohl(t->dst.ip);
-
+#endif
aindex = tmpip % same->ipnum;
new_ip = htonl(same->iparray[aindex]);
return NF_ACCEPT;
}
-int nat_module_is_loaded = 0;
+int nf_nat_module_is_loaded = 0;
static u_int32_t ipv4_get_features(const struct nf_conntrack_tuple *tuple)
{
- if (nat_module_is_loaded)
+ if (nf_nat_module_is_loaded)
return NF_CT_F_NAT;
return NF_CT_F_BASIC;
module_exit(nf_conntrack_l3proto_ipv4_fini);
EXPORT_SYMBOL(nf_ct_ipv4_gather_frags);
+#ifdef CONFIG_NF_NAT_NEEDED
+EXPORT_SYMBOL(nf_nat_module_is_loaded);
+#endif
--- /dev/null
+/* NAT for netfilter; shared with compatibility layer. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/module.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <net/checksum.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/tcp.h> /* For tcp_prot in getorigdst */
+#include <linux/icmp.h>
+#include <linux/udp.h>
+#include <linux/jhash.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+static DEFINE_RWLOCK(nf_nat_lock);
+
+static struct nf_conntrack_l3proto *l3proto = NULL;
+
+/* Calculated at init based on memory size */
+static unsigned int nf_nat_htable_size;
+
+static struct list_head *bysource;
+
+#define MAX_IP_NAT_PROTO 256
+static struct nf_nat_protocol *nf_nat_protos[MAX_IP_NAT_PROTO];
+
+static inline struct nf_nat_protocol *
+__nf_nat_proto_find(u_int8_t protonum)
+{
+ return nf_nat_protos[protonum];
+}
+
+struct nf_nat_protocol *
+nf_nat_proto_find_get(u_int8_t protonum)
+{
+ struct nf_nat_protocol *p;
+
+ /* we need to disable preemption to make sure 'p' doesn't get
+ * removed until we've grabbed the reference */
+ preempt_disable();
+ p = __nf_nat_proto_find(protonum);
+ if (!try_module_get(p->me))
+ p = &nf_nat_unknown_protocol;
+ preempt_enable();
+
+ return p;
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_find_get);
+
+void
+nf_nat_proto_put(struct nf_nat_protocol *p)
+{
+ module_put(p->me);
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_put);
+
+/* We keep an extra hash for each conntrack, for fast searching. */
+static inline unsigned int
+hash_by_src(const struct nf_conntrack_tuple *tuple)
+{
+ /* Original src, to ensure we map it consistently if poss. */
+ return jhash_3words((__force u32)tuple->src.u3.ip, tuple->src.u.all,
+ tuple->dst.protonum, 0) % nf_nat_htable_size;
+}
+
+/* Noone using conntrack by the time this called. */
+static void nf_nat_cleanup_conntrack(struct nf_conn *conn)
+{
+ struct nf_conn_nat *nat;
+ if (!(conn->status & IPS_NAT_DONE_MASK))
+ return;
+
+ nat = nfct_nat(conn);
+ write_lock_bh(&nf_nat_lock);
+ list_del(&nat->info.bysource);
+ write_unlock_bh(&nf_nat_lock);
+}
+
+/* Is this tuple already taken? (not by us) */
+int
+nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
+ const struct nf_conn *ignored_conntrack)
+{
+ /* Conntrack tracking doesn't keep track of outgoing tuples; only
+ incoming ones. NAT means they don't have a fixed mapping,
+ so we invert the tuple and look for the incoming reply.
+
+ We could keep a separate hash if this proves too slow. */
+ struct nf_conntrack_tuple reply;
+
+ nf_ct_invert_tuplepr(&reply, tuple);
+ return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
+}
+EXPORT_SYMBOL(nf_nat_used_tuple);
+
+/* If we source map this tuple so reply looks like reply_tuple, will
+ * that meet the constraints of range. */
+static int
+in_range(const struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range)
+{
+ struct nf_nat_protocol *proto;
+
+ proto = __nf_nat_proto_find(tuple->dst.protonum);
+ /* If we are supposed to map IPs, then we must be in the
+ range specified, otherwise let this drag us onto a new src IP. */
+ if (range->flags & IP_NAT_RANGE_MAP_IPS) {
+ if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) ||
+ ntohl(tuple->src.u3.ip) > ntohl(range->max_ip))
+ return 0;
+ }
+
+ if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) ||
+ proto->in_range(tuple, IP_NAT_MANIP_SRC,
+ &range->min, &range->max))
+ return 1;
+
+ return 0;
+}
+
+static inline int
+same_src(const struct nf_conn *ct,
+ const struct nf_conntrack_tuple *tuple)
+{
+ const struct nf_conntrack_tuple *t;
+
+ t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+ return (t->dst.protonum == tuple->dst.protonum &&
+ t->src.u3.ip == tuple->src.u3.ip &&
+ t->src.u.all == tuple->src.u.all);
+}
+
+/* Only called for SRC manip */
+static int
+find_appropriate_src(const struct nf_conntrack_tuple *tuple,
+ struct nf_conntrack_tuple *result,
+ const struct nf_nat_range *range)
+{
+ unsigned int h = hash_by_src(tuple);
+ struct nf_conn_nat *nat;
+ struct nf_conn *ct;
+
+ read_lock_bh(&nf_nat_lock);
+ list_for_each_entry(nat, &bysource[h], info.bysource) {
+ ct = (struct nf_conn *)((char *)nat - offsetof(struct nf_conn, data));
+ if (same_src(ct, tuple)) {
+ /* Copy source part from reply tuple. */
+ nf_ct_invert_tuplepr(result,
+ &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+ result->dst = tuple->dst;
+
+ if (in_range(result, range)) {
+ read_unlock_bh(&nf_nat_lock);
+ return 1;
+ }
+ }
+ }
+ read_unlock_bh(&nf_nat_lock);
+ return 0;
+}
+
+/* For [FUTURE] fragmentation handling, we want the least-used
+ src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
+ if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
+ 1-65535, we don't do pro-rata allocation based on ports; we choose
+ the ip with the lowest src-ip/dst-ip/proto usage.
+*/
+static void
+find_best_ips_proto(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ const struct nf_conn *ct,
+ enum nf_nat_manip_type maniptype)
+{
+ __be32 *var_ipp;
+ /* Host order */
+ u_int32_t minip, maxip, j;
+
+ /* No IP mapping? Do nothing. */
+ if (!(range->flags & IP_NAT_RANGE_MAP_IPS))
+ return;
+
+ if (maniptype == IP_NAT_MANIP_SRC)
+ var_ipp = &tuple->src.u3.ip;
+ else
+ var_ipp = &tuple->dst.u3.ip;
+
+ /* Fast path: only one choice. */
+ if (range->min_ip == range->max_ip) {
+ *var_ipp = range->min_ip;
+ return;
+ }
+
+ /* Hashing source and destination IPs gives a fairly even
+ * spread in practice (if there are a small number of IPs
+ * involved, there usually aren't that many connections
+ * anyway). The consistency means that servers see the same
+ * client coming from the same IP (some Internet Banking sites
+ * like this), even across reboots. */
+ minip = ntohl(range->min_ip);
+ maxip = ntohl(range->max_ip);
+ j = jhash_2words((__force u32)tuple->src.u3.ip,
+ (__force u32)tuple->dst.u3.ip, 0);
+ *var_ipp = htonl(minip + j % (maxip - minip + 1));
+}
+
+/* Manipulate the tuple into the range given. For NF_IP_POST_ROUTING,
+ * we change the source to map into the range. For NF_IP_PRE_ROUTING
+ * and NF_IP_LOCAL_OUT, we change the destination to map into the
+ * range. It might not be possible to get a unique tuple, but we try.
+ * At worst (or if we race), we will end up with a final duplicate in
+ * __ip_conntrack_confirm and drop the packet. */
+static void
+get_unique_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_conntrack_tuple *orig_tuple,
+ const struct nf_nat_range *range,
+ struct nf_conn *ct,
+ enum nf_nat_manip_type maniptype)
+{
+ struct nf_nat_protocol *proto;
+
+ /* 1) If this srcip/proto/src-proto-part is currently mapped,
+ and that same mapping gives a unique tuple within the given
+ range, use that.
+
+ This is only required for source (ie. NAT/masq) mappings.
+ So far, we don't do local source mappings, so multiple
+ manips not an issue. */
+ if (maniptype == IP_NAT_MANIP_SRC) {
+ if (find_appropriate_src(orig_tuple, tuple, range)) {
+ DEBUGP("get_unique_tuple: Found current src map\n");
+ if (!nf_nat_used_tuple(tuple, ct))
+ return;
+ }
+ }
+
+ /* 2) Select the least-used IP/proto combination in the given
+ range. */
+ *tuple = *orig_tuple;
+ find_best_ips_proto(tuple, range, ct, maniptype);
+
+ /* 3) The per-protocol part of the manip is made to map into
+ the range to make a unique tuple. */
+
+ proto = nf_nat_proto_find_get(orig_tuple->dst.protonum);
+
+ /* Only bother mapping if it's not already in range and unique */
+ if ((!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) ||
+ proto->in_range(tuple, maniptype, &range->min, &range->max)) &&
+ !nf_nat_used_tuple(tuple, ct)) {
+ nf_nat_proto_put(proto);
+ return;
+ }
+
+ /* Last change: get protocol to try to obtain unique tuple. */
+ proto->unique_tuple(tuple, range, maniptype, ct);
+
+ nf_nat_proto_put(proto);
+}
+
+unsigned int
+nf_nat_setup_info(struct nf_conn *ct,
+ const struct nf_nat_range *range,
+ unsigned int hooknum)
+{
+ struct nf_conntrack_tuple curr_tuple, new_tuple;
+ struct nf_conn_nat *nat = nfct_nat(ct);
+ struct nf_nat_info *info = &nat->info;
+ int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK);
+ enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum);
+
+ NF_CT_ASSERT(hooknum == NF_IP_PRE_ROUTING ||
+ hooknum == NF_IP_POST_ROUTING ||
+ hooknum == NF_IP_LOCAL_IN ||
+ hooknum == NF_IP_LOCAL_OUT);
+ BUG_ON(nf_nat_initialized(ct, maniptype));
+
+ /* What we've got will look like inverse of reply. Normally
+ this is what is in the conntrack, except for prior
+ manipulations (future optimization: if num_manips == 0,
+ orig_tp =
+ conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
+ nf_ct_invert_tuplepr(&curr_tuple,
+ &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+ get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
+
+ if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
+ struct nf_conntrack_tuple reply;
+
+ /* Alter conntrack table so will recognize replies. */
+ nf_ct_invert_tuplepr(&reply, &new_tuple);
+ nf_conntrack_alter_reply(ct, &reply);
+
+ /* Non-atomic: we own this at the moment. */
+ if (maniptype == IP_NAT_MANIP_SRC)
+ ct->status |= IPS_SRC_NAT;
+ else
+ ct->status |= IPS_DST_NAT;
+ }
+
+ /* Place in source hash if this is the first time. */
+ if (have_to_hash) {
+ unsigned int srchash;
+
+ srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+ write_lock_bh(&nf_nat_lock);
+ list_add(&info->bysource, &bysource[srchash]);
+ write_unlock_bh(&nf_nat_lock);
+ }
+
+ /* It's done. */
+ if (maniptype == IP_NAT_MANIP_DST)
+ set_bit(IPS_DST_NAT_DONE_BIT, &ct->status);
+ else
+ set_bit(IPS_SRC_NAT_DONE_BIT, &ct->status);
+
+ return NF_ACCEPT;
+}
+EXPORT_SYMBOL(nf_nat_setup_info);
+
+/* Returns true if succeeded. */
+static int
+manip_pkt(u_int16_t proto,
+ struct sk_buff **pskb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *target,
+ enum nf_nat_manip_type maniptype)
+{
+ struct iphdr *iph;
+ struct nf_nat_protocol *p;
+
+ if (!skb_make_writable(pskb, iphdroff + sizeof(*iph)))
+ return 0;
+
+ iph = (void *)(*pskb)->data + iphdroff;
+
+ /* Manipulate protcol part. */
+ p = nf_nat_proto_find_get(proto);
+ if (!p->manip_pkt(pskb, iphdroff, target, maniptype)) {
+ nf_nat_proto_put(p);
+ return 0;
+ }
+ nf_nat_proto_put(p);
+
+ iph = (void *)(*pskb)->data + iphdroff;
+
+ if (maniptype == IP_NAT_MANIP_SRC) {
+ nf_csum_replace4(&iph->check, iph->saddr, target->src.u3.ip);
+ iph->saddr = target->src.u3.ip;
+ } else {
+ nf_csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip);
+ iph->daddr = target->dst.u3.ip;
+ }
+ return 1;
+}
+
+/* Do packet manipulations according to nf_nat_setup_info. */
+unsigned int nf_nat_packet(struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff **pskb)
+{
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ unsigned long statusbit;
+ enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
+
+ if (mtype == IP_NAT_MANIP_SRC)
+ statusbit = IPS_SRC_NAT;
+ else
+ statusbit = IPS_DST_NAT;
+
+ /* Invert if this is reply dir. */
+ if (dir == IP_CT_DIR_REPLY)
+ statusbit ^= IPS_NAT_MASK;
+
+ /* Non-atomic: these bits don't change. */
+ if (ct->status & statusbit) {
+ struct nf_conntrack_tuple target;
+
+ /* We are aiming to look like inverse of other direction. */
+ nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
+
+ if (!manip_pkt(target.dst.protonum, pskb, 0, &target, mtype))
+ return NF_DROP;
+ }
+ return NF_ACCEPT;
+}
+EXPORT_SYMBOL_GPL(nf_nat_packet);
+
+/* Dir is direction ICMP is coming from (opposite to packet it contains) */
+int nf_nat_icmp_reply_translation(struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff **pskb)
+{
+ struct {
+ struct icmphdr icmp;
+ struct iphdr ip;
+ } *inside;
+ struct nf_conntrack_tuple inner, target;
+ int hdrlen = (*pskb)->nh.iph->ihl * 4;
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ unsigned long statusbit;
+ enum nf_nat_manip_type manip = HOOK2MANIP(hooknum);
+
+ if (!skb_make_writable(pskb, hdrlen + sizeof(*inside)))
+ return 0;
+
+ inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+
+ /* We're actually going to mangle it beyond trivial checksum
+ adjustment, so make sure the current checksum is correct. */
+ if (nf_ip_checksum(*pskb, hooknum, hdrlen, 0))
+ return 0;
+
+ /* Must be RELATED */
+ NF_CT_ASSERT((*pskb)->nfctinfo == IP_CT_RELATED ||
+ (*pskb)->nfctinfo == IP_CT_RELATED+IP_CT_IS_REPLY);
+
+ /* Redirects on non-null nats must be dropped, else they'll
+ start talking to each other without our translation, and be
+ confused... --RR */
+ if (inside->icmp.type == ICMP_REDIRECT) {
+ /* If NAT isn't finished, assume it and drop. */
+ if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK)
+ return 0;
+
+ if (ct->status & IPS_NAT_MASK)
+ return 0;
+ }
+
+ DEBUGP("icmp_reply_translation: translating error %p manp %u dir %s\n",
+ *pskb, manip, dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY");
+
+ if (!nf_ct_get_tuple(*pskb,
+ (*pskb)->nh.iph->ihl*4 + sizeof(struct icmphdr),
+ (*pskb)->nh.iph->ihl*4 +
+ sizeof(struct icmphdr) + inside->ip.ihl*4,
+ (u_int16_t)AF_INET,
+ inside->ip.protocol,
+ &inner,
+ l3proto,
+ __nf_ct_l4proto_find((u_int16_t)PF_INET,
+ inside->ip.protocol)))
+ return 0;
+
+ /* Change inner back to look like incoming packet. We do the
+ opposite manip on this hook to normal, because it might not
+ pass all hooks (locally-generated ICMP). Consider incoming
+ packet: PREROUTING (DST manip), routing produces ICMP, goes
+ through POSTROUTING (which must correct the DST manip). */
+ if (!manip_pkt(inside->ip.protocol, pskb,
+ (*pskb)->nh.iph->ihl*4 + sizeof(inside->icmp),
+ &ct->tuplehash[!dir].tuple,
+ !manip))
+ return 0;
+
+ if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
+ /* Reloading "inside" here since manip_pkt inner. */
+ inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+ inside->icmp.checksum = 0;
+ inside->icmp.checksum =
+ csum_fold(skb_checksum(*pskb, hdrlen,
+ (*pskb)->len - hdrlen, 0));
+ }
+
+ /* Change outer to look the reply to an incoming packet
+ * (proto 0 means don't invert per-proto part). */
+ if (manip == IP_NAT_MANIP_SRC)
+ statusbit = IPS_SRC_NAT;
+ else
+ statusbit = IPS_DST_NAT;
+
+ /* Invert if this is reply dir. */
+ if (dir == IP_CT_DIR_REPLY)
+ statusbit ^= IPS_NAT_MASK;
+
+ if (ct->status & statusbit) {
+ nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
+ if (!manip_pkt(0, pskb, 0, &target, manip))
+ return 0;
+ }
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation);
+
+/* Protocol registration. */
+int nf_nat_protocol_register(struct nf_nat_protocol *proto)
+{
+ int ret = 0;
+
+ write_lock_bh(&nf_nat_lock);
+ if (nf_nat_protos[proto->protonum] != &nf_nat_unknown_protocol) {
+ ret = -EBUSY;
+ goto out;
+ }
+ nf_nat_protos[proto->protonum] = proto;
+ out:
+ write_unlock_bh(&nf_nat_lock);
+ return ret;
+}
+EXPORT_SYMBOL(nf_nat_protocol_register);
+
+/* Noone stores the protocol anywhere; simply delete it. */
+void nf_nat_protocol_unregister(struct nf_nat_protocol *proto)
+{
+ write_lock_bh(&nf_nat_lock);
+ nf_nat_protos[proto->protonum] = &nf_nat_unknown_protocol;
+ write_unlock_bh(&nf_nat_lock);
+
+ /* Someone could be still looking at the proto in a bh. */
+ synchronize_net();
+}
+EXPORT_SYMBOL(nf_nat_protocol_unregister);
+
+#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
+ defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
+int
+nf_nat_port_range_to_nfattr(struct sk_buff *skb,
+ const struct nf_nat_range *range)
+{
+ NFA_PUT(skb, CTA_PROTONAT_PORT_MIN, sizeof(__be16),
+ &range->min.tcp.port);
+ NFA_PUT(skb, CTA_PROTONAT_PORT_MAX, sizeof(__be16),
+ &range->max.tcp.port);
+
+ return 0;
+
+nfattr_failure:
+ return -1;
+}
+EXPORT_SYMBOL_GPL(nf_nat_port_nfattr_to_range);
+
+int
+nf_nat_port_nfattr_to_range(struct nfattr *tb[], struct nf_nat_range *range)
+{
+ int ret = 0;
+
+ /* we have to return whether we actually parsed something or not */
+
+ if (tb[CTA_PROTONAT_PORT_MIN-1]) {
+ ret = 1;
+ range->min.tcp.port =
+ *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MIN-1]);
+ }
+
+ if (!tb[CTA_PROTONAT_PORT_MAX-1]) {
+ if (ret)
+ range->max.tcp.port = range->min.tcp.port;
+ } else {
+ ret = 1;
+ range->max.tcp.port =
+ *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MAX-1]);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(nf_nat_port_range_to_nfattr);
+#endif
+
+static int __init nf_nat_init(void)
+{
+ size_t i;
+
+ /* Leave them the same for the moment. */
+ nf_nat_htable_size = nf_conntrack_htable_size;
+
+ /* One vmalloc for both hash tables */
+ bysource = vmalloc(sizeof(struct list_head) * nf_nat_htable_size);
+ if (!bysource)
+ return -ENOMEM;
+
+ /* Sew in builtin protocols. */
+ write_lock_bh(&nf_nat_lock);
+ for (i = 0; i < MAX_IP_NAT_PROTO; i++)
+ nf_nat_protos[i] = &nf_nat_unknown_protocol;
+ nf_nat_protos[IPPROTO_TCP] = &nf_nat_protocol_tcp;
+ nf_nat_protos[IPPROTO_UDP] = &nf_nat_protocol_udp;
+ nf_nat_protos[IPPROTO_ICMP] = &nf_nat_protocol_icmp;
+ write_unlock_bh(&nf_nat_lock);
+
+ for (i = 0; i < nf_nat_htable_size; i++) {
+ INIT_LIST_HEAD(&bysource[i]);
+ }
+
+ /* FIXME: Man, this is a hack. <SIGH> */
+ NF_CT_ASSERT(nf_conntrack_destroyed == NULL);
+ nf_conntrack_destroyed = &nf_nat_cleanup_conntrack;
+
+ /* Initialize fake conntrack so that NAT will skip it */
+ nf_conntrack_untracked.status |= IPS_NAT_DONE_MASK;
+
+ l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET);
+ return 0;
+}
+
+/* Clear NAT section of all conntracks, in case we're loaded again. */
+static int clean_nat(struct nf_conn *i, void *data)
+{
+ struct nf_conn_nat *nat = nfct_nat(i);
+
+ if (!nat)
+ return 0;
+ memset(nat, 0, sizeof(nat));
+ i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST);
+ return 0;
+}
+
+static void __exit nf_nat_cleanup(void)
+{
+ nf_ct_iterate_cleanup(&clean_nat, NULL);
+ nf_conntrack_destroyed = NULL;
+ vfree(bysource);
+ nf_ct_l3proto_put(l3proto);
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(nf_nat_init);
+module_exit(nf_nat_cleanup);
--- /dev/null
+/* ip_nat_helper.c - generic support functions for NAT helpers
+ *
+ * (C) 2000-2002 Harald Welte <laforge@netfilter.org>
+ * (C) 2003-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/module.h>
+#include <linux/kmod.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <net/checksum.h>
+#include <net/tcp.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+
+#if 0
+#define DEBUGP printk
+#define DUMP_OFFSET(x) printk("offset_before=%d, offset_after=%d, correction_pos=%u\n", x->offset_before, x->offset_after, x->correction_pos);
+#else
+#define DEBUGP(format, args...)
+#define DUMP_OFFSET(x)
+#endif
+
+static DEFINE_SPINLOCK(nf_nat_seqofs_lock);
+
+/* Setup TCP sequence correction given this change at this sequence */
+static inline void
+adjust_tcp_sequence(u32 seq,
+ int sizediff,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ int dir;
+ struct nf_nat_seq *this_way, *other_way;
+ struct nf_conn_nat *nat = nfct_nat(ct);
+
+ DEBUGP("nf_nat_resize_packet: old_size = %u, new_size = %u\n",
+ (*skb)->len, new_size);
+
+ dir = CTINFO2DIR(ctinfo);
+
+ this_way = &nat->info.seq[dir];
+ other_way = &nat->info.seq[!dir];
+
+ DEBUGP("nf_nat_resize_packet: Seq_offset before: ");
+ DUMP_OFFSET(this_way);
+
+ spin_lock_bh(&nf_nat_seqofs_lock);
+
+ /* SYN adjust. If it's uninitialized, or this is after last
+ * correction, record it: we don't handle more than one
+ * adjustment in the window, but do deal with common case of a
+ * retransmit */
+ if (this_way->offset_before == this_way->offset_after ||
+ before(this_way->correction_pos, seq)) {
+ this_way->correction_pos = seq;
+ this_way->offset_before = this_way->offset_after;
+ this_way->offset_after += sizediff;
+ }
+ spin_unlock_bh(&nf_nat_seqofs_lock);
+
+ DEBUGP("nf_nat_resize_packet: Seq_offset after: ");
+ DUMP_OFFSET(this_way);
+}
+
+/* Frobs data inside this packet, which is linear. */
+static void mangle_contents(struct sk_buff *skb,
+ unsigned int dataoff,
+ unsigned int match_offset,
+ unsigned int match_len,
+ const char *rep_buffer,
+ unsigned int rep_len)
+{
+ unsigned char *data;
+
+ BUG_ON(skb_is_nonlinear(skb));
+ data = (unsigned char *)skb->nh.iph + dataoff;
+
+ /* move post-replacement */
+ memmove(data + match_offset + rep_len,
+ data + match_offset + match_len,
+ skb->tail - (data + match_offset + match_len));
+
+ /* insert data from buffer */
+ memcpy(data + match_offset, rep_buffer, rep_len);
+
+ /* update skb info */
+ if (rep_len > match_len) {
+ DEBUGP("nf_nat_mangle_packet: Extending packet by "
+ "%u from %u bytes\n", rep_len - match_len,
+ skb->len);
+ skb_put(skb, rep_len - match_len);
+ } else {
+ DEBUGP("nf_nat_mangle_packet: Shrinking packet from "
+ "%u from %u bytes\n", match_len - rep_len,
+ skb->len);
+ __skb_trim(skb, skb->len + rep_len - match_len);
+ }
+
+ /* fix IP hdr checksum information */
+ skb->nh.iph->tot_len = htons(skb->len);
+ ip_send_check(skb->nh.iph);
+}
+
+/* Unusual, but possible case. */
+static int enlarge_skb(struct sk_buff **pskb, unsigned int extra)
+{
+ struct sk_buff *nskb;
+
+ if ((*pskb)->len + extra > 65535)
+ return 0;
+
+ nskb = skb_copy_expand(*pskb, skb_headroom(*pskb), extra, GFP_ATOMIC);
+ if (!nskb)
+ return 0;
+
+ /* Transfer socket to new skb. */
+ if ((*pskb)->sk)
+ skb_set_owner_w(nskb, (*pskb)->sk);
+ kfree_skb(*pskb);
+ *pskb = nskb;
+ return 1;
+}
+
+/* Generic function for mangling variable-length address changes inside
+ * NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
+ * command in FTP).
+ *
+ * Takes care about all the nasty sequence number changes, checksumming,
+ * skb enlargement, ...
+ *
+ * */
+int
+nf_nat_mangle_tcp_packet(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int match_offset,
+ unsigned int match_len,
+ const char *rep_buffer,
+ unsigned int rep_len)
+{
+ struct iphdr *iph;
+ struct tcphdr *tcph;
+ int oldlen, datalen;
+
+ if (!skb_make_writable(pskb, (*pskb)->len))
+ return 0;
+
+ if (rep_len > match_len &&
+ rep_len - match_len > skb_tailroom(*pskb) &&
+ !enlarge_skb(pskb, rep_len - match_len))
+ return 0;
+
+ SKB_LINEAR_ASSERT(*pskb);
+
+ iph = (*pskb)->nh.iph;
+ tcph = (void *)iph + iph->ihl*4;
+
+ oldlen = (*pskb)->len - iph->ihl*4;
+ mangle_contents(*pskb, iph->ihl*4 + tcph->doff*4,
+ match_offset, match_len, rep_buffer, rep_len);
+
+ datalen = (*pskb)->len - iph->ihl*4;
+ if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
+ tcph->check = 0;
+ tcph->check = tcp_v4_check(tcph, datalen,
+ iph->saddr, iph->daddr,
+ csum_partial((char *)tcph,
+ datalen, 0));
+ } else
+ nf_proto_csum_replace2(&tcph->check, *pskb,
+ htons(oldlen), htons(datalen), 1);
+
+ if (rep_len != match_len) {
+ set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
+ adjust_tcp_sequence(ntohl(tcph->seq),
+ (int)rep_len - (int)match_len,
+ ct, ctinfo);
+ /* Tell TCP window tracking about seq change */
+ nf_conntrack_tcp_update(*pskb, (*pskb)->nh.iph->ihl*4,
+ ct, CTINFO2DIR(ctinfo));
+ }
+ return 1;
+}
+EXPORT_SYMBOL(nf_nat_mangle_tcp_packet);
+
+/* Generic function for mangling variable-length address changes inside
+ * NATed UDP connections (like the CONNECT DATA XXXXX MESG XXXXX INDEX XXXXX
+ * command in the Amanda protocol)
+ *
+ * Takes care about all the nasty sequence number changes, checksumming,
+ * skb enlargement, ...
+ *
+ * XXX - This function could be merged with nf_nat_mangle_tcp_packet which
+ * should be fairly easy to do.
+ */
+int
+nf_nat_mangle_udp_packet(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned int match_offset,
+ unsigned int match_len,
+ const char *rep_buffer,
+ unsigned int rep_len)
+{
+ struct iphdr *iph;
+ struct udphdr *udph;
+ int datalen, oldlen;
+
+ /* UDP helpers might accidentally mangle the wrong packet */
+ iph = (*pskb)->nh.iph;
+ if ((*pskb)->len < iph->ihl*4 + sizeof(*udph) +
+ match_offset + match_len)
+ return 0;
+
+ if (!skb_make_writable(pskb, (*pskb)->len))
+ return 0;
+
+ if (rep_len > match_len &&
+ rep_len - match_len > skb_tailroom(*pskb) &&
+ !enlarge_skb(pskb, rep_len - match_len))
+ return 0;
+
+ iph = (*pskb)->nh.iph;
+ udph = (void *)iph + iph->ihl*4;
+
+ oldlen = (*pskb)->len - iph->ihl*4;
+ mangle_contents(*pskb, iph->ihl*4 + sizeof(*udph),
+ match_offset, match_len, rep_buffer, rep_len);
+
+ /* update the length of the UDP packet */
+ datalen = (*pskb)->len - iph->ihl*4;
+ udph->len = htons(datalen);
+
+ /* fix udp checksum if udp checksum was previously calculated */
+ if (!udph->check && (*pskb)->ip_summed != CHECKSUM_PARTIAL)
+ return 1;
+
+ if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
+ udph->check = 0;
+ udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+ datalen, IPPROTO_UDP,
+ csum_partial((char *)udph,
+ datalen, 0));
+ if (!udph->check)
+ udph->check = CSUM_MANGLED_0;
+ } else
+ nf_proto_csum_replace2(&udph->check, *pskb,
+ htons(oldlen), htons(datalen), 1);
+
+ return 1;
+}
+EXPORT_SYMBOL(nf_nat_mangle_udp_packet);
+
+/* Adjust one found SACK option including checksum correction */
+static void
+sack_adjust(struct sk_buff *skb,
+ struct tcphdr *tcph,
+ unsigned int sackoff,
+ unsigned int sackend,
+ struct nf_nat_seq *natseq)
+{
+ while (sackoff < sackend) {
+ struct tcp_sack_block_wire *sack;
+ __be32 new_start_seq, new_end_seq;
+
+ sack = (void *)skb->data + sackoff;
+ if (after(ntohl(sack->start_seq) - natseq->offset_before,
+ natseq->correction_pos))
+ new_start_seq = htonl(ntohl(sack->start_seq)
+ - natseq->offset_after);
+ else
+ new_start_seq = htonl(ntohl(sack->start_seq)
+ - natseq->offset_before);
+
+ if (after(ntohl(sack->end_seq) - natseq->offset_before,
+ natseq->correction_pos))
+ new_end_seq = htonl(ntohl(sack->end_seq)
+ - natseq->offset_after);
+ else
+ new_end_seq = htonl(ntohl(sack->end_seq)
+ - natseq->offset_before);
+
+ DEBUGP("sack_adjust: start_seq: %d->%d, end_seq: %d->%d\n",
+ ntohl(sack->start_seq), new_start_seq,
+ ntohl(sack->end_seq), new_end_seq);
+
+ nf_proto_csum_replace4(&tcph->check, skb,
+ sack->start_seq, new_start_seq, 0);
+ nf_proto_csum_replace4(&tcph->check, skb,
+ sack->end_seq, new_end_seq, 0);
+ sack->start_seq = new_start_seq;
+ sack->end_seq = new_end_seq;
+ sackoff += sizeof(*sack);
+ }
+}
+
+/* TCP SACK sequence number adjustment */
+static inline unsigned int
+nf_nat_sack_adjust(struct sk_buff **pskb,
+ struct tcphdr *tcph,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ unsigned int dir, optoff, optend;
+ struct nf_conn_nat *nat = nfct_nat(ct);
+
+ optoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct tcphdr);
+ optend = (*pskb)->nh.iph->ihl*4 + tcph->doff*4;
+
+ if (!skb_make_writable(pskb, optend))
+ return 0;
+
+ dir = CTINFO2DIR(ctinfo);
+
+ while (optoff < optend) {
+ /* Usually: option, length. */
+ unsigned char *op = (*pskb)->data + optoff;
+
+ switch (op[0]) {
+ case TCPOPT_EOL:
+ return 1;
+ case TCPOPT_NOP:
+ optoff++;
+ continue;
+ default:
+ /* no partial options */
+ if (optoff + 1 == optend ||
+ optoff + op[1] > optend ||
+ op[1] < 2)
+ return 0;
+ if (op[0] == TCPOPT_SACK &&
+ op[1] >= 2+TCPOLEN_SACK_PERBLOCK &&
+ ((op[1] - 2) % TCPOLEN_SACK_PERBLOCK) == 0)
+ sack_adjust(*pskb, tcph, optoff+2,
+ optoff+op[1],
+ &nat->info.seq[!dir]);
+ optoff += op[1];
+ }
+ }
+ return 1;
+}
+
+/* TCP sequence number adjustment. Returns 1 on success, 0 on failure */
+int
+nf_nat_seq_adjust(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ struct tcphdr *tcph;
+ int dir;
+ __be32 newseq, newack;
+ struct nf_conn_nat *nat = nfct_nat(ct);
+ struct nf_nat_seq *this_way, *other_way;
+
+ dir = CTINFO2DIR(ctinfo);
+
+ this_way = &nat->info.seq[dir];
+ other_way = &nat->info.seq[!dir];
+
+ if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+ return 0;
+
+ tcph = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+ if (after(ntohl(tcph->seq), this_way->correction_pos))
+ newseq = htonl(ntohl(tcph->seq) + this_way->offset_after);
+ else
+ newseq = htonl(ntohl(tcph->seq) + this_way->offset_before);
+
+ if (after(ntohl(tcph->ack_seq) - other_way->offset_before,
+ other_way->correction_pos))
+ newack = htonl(ntohl(tcph->ack_seq) - other_way->offset_after);
+ else
+ newack = htonl(ntohl(tcph->ack_seq) - other_way->offset_before);
+
+ nf_proto_csum_replace4(&tcph->check, *pskb, tcph->seq, newseq, 0);
+ nf_proto_csum_replace4(&tcph->check, *pskb, tcph->ack_seq, newack, 0);
+
+ DEBUGP("Adjusting sequence number from %u->%u, ack from %u->%u\n",
+ ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq),
+ ntohl(newack));
+
+ tcph->seq = newseq;
+ tcph->ack_seq = newack;
+
+ if (!nf_nat_sack_adjust(pskb, tcph, ct, ctinfo))
+ return 0;
+
+ nf_conntrack_tcp_update(*pskb, (*pskb)->nh.iph->ihl*4, ct, dir);
+
+ return 1;
+}
+EXPORT_SYMBOL(nf_nat_seq_adjust);
+
+/* Setup NAT on this expected conntrack so it follows master. */
+/* If we fail to get a free NAT slot, we'll get dropped on confirm */
+void nf_nat_follow_master(struct nf_conn *ct,
+ struct nf_conntrack_expect *exp)
+{
+ struct nf_nat_range range;
+
+ /* This must be a fresh one. */
+ BUG_ON(ct->status & IPS_NAT_DONE_MASK);
+
+ /* Change src to where master sends to */
+ range.flags = IP_NAT_RANGE_MAP_IPS;
+ range.min_ip = range.max_ip
+ = ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+ /* hook doesn't matter, but it has to do source manip */
+ nf_nat_setup_info(ct, &range, NF_IP_POST_ROUTING);
+
+ /* For DST manip, map port here to where it's expected. */
+ range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
+ range.min = range.max = exp->saved_proto;
+ range.min_ip = range.max_ip
+ = ct->master->tuplehash[!exp->dir].tuple.src.u3.ip;
+ /* hook doesn't matter, but it has to do destination manip */
+ nf_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING);
+}
+EXPORT_SYMBOL(nf_nat_follow_master);
--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static int
+icmp_in_range(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max)
+{
+ return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) &&
+ ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
+}
+
+static int
+icmp_unique_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct)
+{
+ static u_int16_t id;
+ unsigned int range_size;
+ unsigned int i;
+
+ range_size = ntohs(range->max.icmp.id) - ntohs(range->min.icmp.id) + 1;
+ /* If no range specified... */
+ if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED))
+ range_size = 0xFFFF;
+
+ for (i = 0; i < range_size; i++, id++) {
+ tuple->src.u.icmp.id = htons(ntohs(range->min.icmp.id) +
+ (id % range_size));
+ if (!nf_nat_used_tuple(tuple, ct))
+ return 1;
+ }
+ return 0;
+}
+
+static int
+icmp_manip_pkt(struct sk_buff **pskb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype)
+{
+ struct iphdr *iph = (struct iphdr *)((*pskb)->data + iphdroff);
+ struct icmphdr *hdr;
+ unsigned int hdroff = iphdroff + iph->ihl*4;
+
+ if (!skb_make_writable(pskb, hdroff + sizeof(*hdr)))
+ return 0;
+
+ hdr = (struct icmphdr *)((*pskb)->data + hdroff);
+ nf_proto_csum_replace2(&hdr->checksum, *pskb,
+ hdr->un.echo.id, tuple->src.u.icmp.id, 0);
+ hdr->un.echo.id = tuple->src.u.icmp.id;
+ return 1;
+}
+
+struct nf_nat_protocol nf_nat_protocol_icmp = {
+ .name = "ICMP",
+ .protonum = IPPROTO_ICMP,
+ .me = THIS_MODULE,
+ .manip_pkt = icmp_manip_pkt,
+ .in_range = icmp_in_range,
+ .unique_tuple = icmp_unique_tuple,
+#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
+ defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
+ .range_to_nfattr = nf_nat_port_range_to_nfattr,
+ .nfattr_to_range = nf_nat_port_nfattr_to_range,
+#endif
+};
--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+
+static int
+tcp_in_range(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max)
+{
+ __be16 port;
+
+ if (maniptype == IP_NAT_MANIP_SRC)
+ port = tuple->src.u.tcp.port;
+ else
+ port = tuple->dst.u.tcp.port;
+
+ return ntohs(port) >= ntohs(min->tcp.port) &&
+ ntohs(port) <= ntohs(max->tcp.port);
+}
+
+static int
+tcp_unique_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct)
+{
+ static u_int16_t port;
+ __be16 *portptr;
+ unsigned int range_size, min, i;
+
+ if (maniptype == IP_NAT_MANIP_SRC)
+ portptr = &tuple->src.u.tcp.port;
+ else
+ portptr = &tuple->dst.u.tcp.port;
+
+ /* If no range specified... */
+ if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
+ /* If it's dst rewrite, can't change port */
+ if (maniptype == IP_NAT_MANIP_DST)
+ return 0;
+
+ /* Map privileged onto privileged. */
+ if (ntohs(*portptr) < 1024) {
+ /* Loose convention: >> 512 is credential passing */
+ if (ntohs(*portptr)<512) {
+ min = 1;
+ range_size = 511 - min + 1;
+ } else {
+ min = 600;
+ range_size = 1023 - min + 1;
+ }
+ } else {
+ min = 1024;
+ range_size = 65535 - 1024 + 1;
+ }
+ } else {
+ min = ntohs(range->min.tcp.port);
+ range_size = ntohs(range->max.tcp.port) - min + 1;
+ }
+
+ for (i = 0; i < range_size; i++, port++) {
+ *portptr = htons(min + port % range_size);
+ if (!nf_nat_used_tuple(tuple, ct))
+ return 1;
+ }
+ return 0;
+}
+
+static int
+tcp_manip_pkt(struct sk_buff **pskb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype)
+{
+ struct iphdr *iph = (struct iphdr *)((*pskb)->data + iphdroff);
+ struct tcphdr *hdr;
+ unsigned int hdroff = iphdroff + iph->ihl*4;
+ __be32 oldip, newip;
+ __be16 *portptr, newport, oldport;
+ int hdrsize = 8; /* TCP connection tracking guarantees this much */
+
+ /* this could be a inner header returned in icmp packet; in such
+ cases we cannot update the checksum field since it is outside of
+ the 8 bytes of transport layer headers we are guaranteed */
+ if ((*pskb)->len >= hdroff + sizeof(struct tcphdr))
+ hdrsize = sizeof(struct tcphdr);
+
+ if (!skb_make_writable(pskb, hdroff + hdrsize))
+ return 0;
+
+ iph = (struct iphdr *)((*pskb)->data + iphdroff);
+ hdr = (struct tcphdr *)((*pskb)->data + hdroff);
+
+ if (maniptype == IP_NAT_MANIP_SRC) {
+ /* Get rid of src ip and src pt */
+ oldip = iph->saddr;
+ newip = tuple->src.u3.ip;
+ newport = tuple->src.u.tcp.port;
+ portptr = &hdr->source;
+ } else {
+ /* Get rid of dst ip and dst pt */
+ oldip = iph->daddr;
+ newip = tuple->dst.u3.ip;
+ newport = tuple->dst.u.tcp.port;
+ portptr = &hdr->dest;
+ }
+
+ oldport = *portptr;
+ *portptr = newport;
+
+ if (hdrsize < sizeof(*hdr))
+ return 1;
+
+ nf_proto_csum_replace4(&hdr->check, *pskb, oldip, newip, 1);
+ nf_proto_csum_replace2(&hdr->check, *pskb, oldport, newport, 0);
+ return 1;
+}
+
+struct nf_nat_protocol nf_nat_protocol_tcp = {
+ .name = "TCP",
+ .protonum = IPPROTO_TCP,
+ .me = THIS_MODULE,
+ .manip_pkt = tcp_manip_pkt,
+ .in_range = tcp_in_range,
+ .unique_tuple = tcp_unique_tuple,
+#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
+ defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
+ .range_to_nfattr = nf_nat_port_range_to_nfattr,
+ .nfattr_to_range = nf_nat_port_nfattr_to_range,
+#endif
+};
--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static int
+udp_in_range(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max)
+{
+ __be16 port;
+
+ if (maniptype == IP_NAT_MANIP_SRC)
+ port = tuple->src.u.udp.port;
+ else
+ port = tuple->dst.u.udp.port;
+
+ return ntohs(port) >= ntohs(min->udp.port) &&
+ ntohs(port) <= ntohs(max->udp.port);
+}
+
+static int
+udp_unique_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct)
+{
+ static u_int16_t port;
+ __be16 *portptr;
+ unsigned int range_size, min, i;
+
+ if (maniptype == IP_NAT_MANIP_SRC)
+ portptr = &tuple->src.u.udp.port;
+ else
+ portptr = &tuple->dst.u.udp.port;
+
+ /* If no range specified... */
+ if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
+ /* If it's dst rewrite, can't change port */
+ if (maniptype == IP_NAT_MANIP_DST)
+ return 0;
+
+ if (ntohs(*portptr) < 1024) {
+ /* Loose convention: >> 512 is credential passing */
+ if (ntohs(*portptr)<512) {
+ min = 1;
+ range_size = 511 - min + 1;
+ } else {
+ min = 600;
+ range_size = 1023 - min + 1;
+ }
+ } else {
+ min = 1024;
+ range_size = 65535 - 1024 + 1;
+ }
+ } else {
+ min = ntohs(range->min.udp.port);
+ range_size = ntohs(range->max.udp.port) - min + 1;
+ }
+
+ for (i = 0; i < range_size; i++, port++) {
+ *portptr = htons(min + port % range_size);
+ if (!nf_nat_used_tuple(tuple, ct))
+ return 1;
+ }
+ return 0;
+}
+
+static int
+udp_manip_pkt(struct sk_buff **pskb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype)
+{
+ struct iphdr *iph = (struct iphdr *)((*pskb)->data + iphdroff);
+ struct udphdr *hdr;
+ unsigned int hdroff = iphdroff + iph->ihl*4;
+ __be32 oldip, newip;
+ __be16 *portptr, newport;
+
+ if (!skb_make_writable(pskb, hdroff + sizeof(*hdr)))
+ return 0;
+
+ iph = (struct iphdr *)((*pskb)->data + iphdroff);
+ hdr = (struct udphdr *)((*pskb)->data + hdroff);
+
+ if (maniptype == IP_NAT_MANIP_SRC) {
+ /* Get rid of src ip and src pt */
+ oldip = iph->saddr;
+ newip = tuple->src.u3.ip;
+ newport = tuple->src.u.udp.port;
+ portptr = &hdr->source;
+ } else {
+ /* Get rid of dst ip and dst pt */
+ oldip = iph->daddr;
+ newip = tuple->dst.u3.ip;
+ newport = tuple->dst.u.udp.port;
+ portptr = &hdr->dest;
+ }
+ if (hdr->check || (*pskb)->ip_summed == CHECKSUM_PARTIAL) {
+ nf_proto_csum_replace4(&hdr->check, *pskb, oldip, newip, 1);
+ nf_proto_csum_replace2(&hdr->check, *pskb, *portptr, newport,
+ 0);
+ if (!hdr->check)
+ hdr->check = CSUM_MANGLED_0;
+ }
+ *portptr = newport;
+ return 1;
+}
+
+struct nf_nat_protocol nf_nat_protocol_udp = {
+ .name = "UDP",
+ .protonum = IPPROTO_UDP,
+ .me = THIS_MODULE,
+ .manip_pkt = udp_manip_pkt,
+ .in_range = udp_in_range,
+ .unique_tuple = udp_unique_tuple,
+#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
+ defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
+ .range_to_nfattr = nf_nat_port_range_to_nfattr,
+ .nfattr_to_range = nf_nat_port_nfattr_to_range,
+#endif
+};
--- /dev/null
+/* The "unknown" protocol. This is what is used for protocols we
+ * don't understand. It's returned by ip_ct_find_proto().
+ */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/types.h>
+#include <linux/init.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static int unknown_in_range(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type manip_type,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max)
+{
+ return 1;
+}
+
+static int unknown_unique_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct)
+{
+ /* Sorry: we can't help you; if it's not unique, we can't frob
+ anything. */
+ return 0;
+}
+
+static int
+unknown_manip_pkt(struct sk_buff **pskb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype)
+{
+ return 1;
+}
+
+struct nf_nat_protocol nf_nat_unknown_protocol = {
+ .name = "unknown",
+ /* .me isn't set: getting a ref to this cannot fail. */
+ .manip_pkt = unknown_manip_pkt,
+ .in_range = unknown_in_range,
+ .unique_tuple = unknown_unique_tuple,
+};
--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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.
+ */
+
+/* Everything about the rules for NAT. */
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <net/checksum.h>
+#include <net/route.h>
+#include <linux/bitops.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+#define NAT_VALID_HOOKS ((1<<NF_IP_PRE_ROUTING) | (1<<NF_IP_POST_ROUTING) | (1<<NF_IP_LOCAL_OUT))
+
+static struct
+{
+ struct ipt_replace repl;
+ struct ipt_standard entries[3];
+ struct ipt_error term;
+} nat_initial_table __initdata = {
+ .repl = {
+ .name = "nat",
+ .valid_hooks = NAT_VALID_HOOKS,
+ .num_entries = 4,
+ .size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
+ .hook_entry = {
+ [NF_IP_PRE_ROUTING] = 0,
+ [NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
+ [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
+ .underflow = {
+ [NF_IP_PRE_ROUTING] = 0,
+ [NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
+ [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
+ },
+ .entries = {
+ /* PRE_ROUTING */
+ {
+ .entry = {
+ .target_offset = sizeof(struct ipt_entry),
+ .next_offset = sizeof(struct ipt_standard),
+ },
+ .target = {
+ .target = {
+ .u = {
+ .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
+ },
+ },
+ .verdict = -NF_ACCEPT - 1,
+ },
+ },
+ /* POST_ROUTING */
+ {
+ .entry = {
+ .target_offset = sizeof(struct ipt_entry),
+ .next_offset = sizeof(struct ipt_standard),
+ },
+ .target = {
+ .target = {
+ .u = {
+ .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
+ },
+ },
+ .verdict = -NF_ACCEPT - 1,
+ },
+ },
+ /* LOCAL_OUT */
+ {
+ .entry = {
+ .target_offset = sizeof(struct ipt_entry),
+ .next_offset = sizeof(struct ipt_standard),
+ },
+ .target = {
+ .target = {
+ .u = {
+ .target_size = IPT_ALIGN(sizeof(struct ipt_standard_target)),
+ },
+ },
+ .verdict = -NF_ACCEPT - 1,
+ },
+ },
+ },
+ /* ERROR */
+ .term = {
+ .entry = {
+ .target_offset = sizeof(struct ipt_entry),
+ .next_offset = sizeof(struct ipt_error),
+ },
+ .target = {
+ .target = {
+ .u = {
+ .user = {
+ .target_size = IPT_ALIGN(sizeof(struct ipt_error_target)),
+ .name = IPT_ERROR_TARGET,
+ },
+ },
+ },
+ .errorname = "ERROR",
+ },
+ }
+};
+
+static struct ipt_table nat_table = {
+ .name = "nat",
+ .valid_hooks = NAT_VALID_HOOKS,
+ .lock = RW_LOCK_UNLOCKED,
+ .me = THIS_MODULE,
+ .af = AF_INET,
+};
+
+/* Source NAT */
+static unsigned int ipt_snat_target(struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const struct xt_target *target,
+ const void *targinfo)
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ const struct nf_nat_multi_range_compat *mr = targinfo;
+
+ NF_CT_ASSERT(hooknum == NF_IP_POST_ROUTING);
+
+ ct = nf_ct_get(*pskb, &ctinfo);
+
+ /* Connection must be valid and new. */
+ NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED ||
+ ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
+ NF_CT_ASSERT(out);
+
+ return nf_nat_setup_info(ct, &mr->range[0], hooknum);
+}
+
+/* Before 2.6.11 we did implicit source NAT if required. Warn about change. */
+static void warn_if_extra_mangle(__be32 dstip, __be32 srcip)
+{
+ static int warned = 0;
+ struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dstip } } };
+ struct rtable *rt;
+
+ if (ip_route_output_key(&rt, &fl) != 0)
+ return;
+
+ if (rt->rt_src != srcip && !warned) {
+ printk("NAT: no longer support implicit source local NAT\n");
+ printk("NAT: packet src %u.%u.%u.%u -> dst %u.%u.%u.%u\n",
+ NIPQUAD(srcip), NIPQUAD(dstip));
+ warned = 1;
+ }
+ ip_rt_put(rt);
+}
+
+static unsigned int ipt_dnat_target(struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const struct xt_target *target,
+ const void *targinfo)
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ const struct nf_nat_multi_range_compat *mr = targinfo;
+
+ NF_CT_ASSERT(hooknum == NF_IP_PRE_ROUTING ||
+ hooknum == NF_IP_LOCAL_OUT);
+
+ ct = nf_ct_get(*pskb, &ctinfo);
+
+ /* Connection must be valid and new. */
+ NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
+
+ if (hooknum == NF_IP_LOCAL_OUT &&
+ mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)
+ warn_if_extra_mangle((*pskb)->nh.iph->daddr,
+ mr->range[0].min_ip);
+
+ return nf_nat_setup_info(ct, &mr->range[0], hooknum);
+}
+
+static int ipt_snat_checkentry(const char *tablename,
+ const void *entry,
+ const struct xt_target *target,
+ void *targinfo,
+ unsigned int hook_mask)
+{
+ struct nf_nat_multi_range_compat *mr = targinfo;
+
+ /* Must be a valid range */
+ if (mr->rangesize != 1) {
+ printk("SNAT: multiple ranges no longer supported\n");
+ return 0;
+ }
+ return 1;
+}
+
+static int ipt_dnat_checkentry(const char *tablename,
+ const void *entry,
+ const struct xt_target *target,
+ void *targinfo,
+ unsigned int hook_mask)
+{
+ struct nf_nat_multi_range_compat *mr = targinfo;
+
+ /* Must be a valid range */
+ if (mr->rangesize != 1) {
+ printk("DNAT: multiple ranges no longer supported\n");
+ return 0;
+ }
+ return 1;
+}
+
+inline unsigned int
+alloc_null_binding(struct nf_conn *ct,
+ struct nf_nat_info *info,
+ unsigned int hooknum)
+{
+ /* Force range to this IP; let proto decide mapping for
+ per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
+ Use reply in case it's already been mangled (eg local packet).
+ */
+ __be32 ip
+ = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
+ ? ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip
+ : ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip);
+ struct nf_nat_range range
+ = { IP_NAT_RANGE_MAP_IPS, ip, ip, { 0 }, { 0 } };
+
+ DEBUGP("Allocating NULL binding for %p (%u.%u.%u.%u)\n",
+ ct, NIPQUAD(ip));
+ return nf_nat_setup_info(ct, &range, hooknum);
+}
+
+unsigned int
+alloc_null_binding_confirmed(struct nf_conn *ct,
+ struct nf_nat_info *info,
+ unsigned int hooknum)
+{
+ __be32 ip
+ = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
+ ? ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip
+ : ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip);
+ u_int16_t all
+ = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
+ ? ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all
+ : ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all);
+ struct nf_nat_range range
+ = { IP_NAT_RANGE_MAP_IPS, ip, ip, { all }, { all } };
+
+ DEBUGP("Allocating NULL binding for confirmed %p (%u.%u.%u.%u)\n",
+ ct, NIPQUAD(ip));
+ return nf_nat_setup_info(ct, &range, hooknum);
+}
+
+int nf_nat_rule_find(struct sk_buff **pskb,
+ unsigned int hooknum,
+ const struct net_device *in,
+ const struct net_device *out,
+ struct nf_conn *ct,
+ struct nf_nat_info *info)
+{
+ int ret;
+
+ ret = ipt_do_table(pskb, hooknum, in, out, &nat_table);
+
+ if (ret == NF_ACCEPT) {
+ if (!nf_nat_initialized(ct, HOOK2MANIP(hooknum)))
+ /* NUL mapping */
+ ret = alloc_null_binding(ct, info, hooknum);
+ }
+ return ret;
+}
+
+static struct ipt_target ipt_snat_reg = {
+ .name = "SNAT",
+ .target = ipt_snat_target,
+ .targetsize = sizeof(struct nf_nat_multi_range_compat),
+ .table = "nat",
+ .hooks = 1 << NF_IP_POST_ROUTING,
+ .checkentry = ipt_snat_checkentry,
+ .family = AF_INET,
+};
+
+static struct xt_target ipt_dnat_reg = {
+ .name = "DNAT",
+ .target = ipt_dnat_target,
+ .targetsize = sizeof(struct nf_nat_multi_range_compat),
+ .table = "nat",
+ .hooks = (1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT),
+ .checkentry = ipt_dnat_checkentry,
+ .family = AF_INET,
+};
+
+int __init nf_nat_rule_init(void)
+{
+ int ret;
+
+ ret = ipt_register_table(&nat_table, &nat_initial_table.repl);
+ if (ret != 0)
+ return ret;
+ ret = xt_register_target(&ipt_snat_reg);
+ if (ret != 0)
+ goto unregister_table;
+
+ ret = xt_register_target(&ipt_dnat_reg);
+ if (ret != 0)
+ goto unregister_snat;
+
+ return ret;
+
+ unregister_snat:
+ xt_unregister_target(&ipt_snat_reg);
+ unregister_table:
+ ipt_unregister_table(&nat_table);
+
+ return ret;
+}
+
+void nf_nat_rule_cleanup(void)
+{
+ xt_unregister_target(&ipt_dnat_reg);
+ xt_unregister_target(&ipt_snat_reg);
+ ipt_unregister_table(&nat_table);
+}
--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/types.h>
+#include <linux/icmp.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include <linux/spinlock.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+#define HOOKNAME(hooknum) ((hooknum) == NF_IP_POST_ROUTING ? "POST_ROUTING" \
+ : ((hooknum) == NF_IP_PRE_ROUTING ? "PRE_ROUTING" \
+ : ((hooknum) == NF_IP_LOCAL_OUT ? "LOCAL_OUT" \
+ : ((hooknum) == NF_IP_LOCAL_IN ? "LOCAL_IN" \
+ : "*ERROR*")))
+
+#ifdef CONFIG_XFRM
+static void nat_decode_session(struct sk_buff *skb, struct flowi *fl)
+{
+ struct nf_conn *ct;
+ struct nf_conntrack_tuple *t;
+ enum ip_conntrack_info ctinfo;
+ enum ip_conntrack_dir dir;
+ unsigned long statusbit;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (ct == NULL)
+ return;
+ dir = CTINFO2DIR(ctinfo);
+ t = &ct->tuplehash[dir].tuple;
+
+ if (dir == IP_CT_DIR_ORIGINAL)
+ statusbit = IPS_DST_NAT;
+ else
+ statusbit = IPS_SRC_NAT;
+
+ if (ct->status & statusbit) {
+ fl->fl4_dst = t->dst.u3.ip;
+ if (t->dst.protonum == IPPROTO_TCP ||
+ t->dst.protonum == IPPROTO_UDP)
+ fl->fl_ip_dport = t->dst.u.tcp.port;
+ }
+
+ statusbit ^= IPS_NAT_MASK;
+
+ if (ct->status & statusbit) {
+ fl->fl4_src = t->src.u3.ip;
+ if (t->dst.protonum == IPPROTO_TCP ||
+ t->dst.protonum == IPPROTO_UDP)
+ fl->fl_ip_sport = t->src.u.tcp.port;
+ }
+}
+#endif
+
+static unsigned int
+nf_nat_fn(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn_nat *nat;
+ struct nf_nat_info *info;
+ /* maniptype == SRC for postrouting. */
+ enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum);
+
+ /* We never see fragments: conntrack defrags on pre-routing
+ and local-out, and nf_nat_out protects post-routing. */
+ NF_CT_ASSERT(!((*pskb)->nh.iph->frag_off
+ & htons(IP_MF|IP_OFFSET)));
+
+ ct = nf_ct_get(*pskb, &ctinfo);
+ /* Can't track? It's not due to stress, or conntrack would
+ have dropped it. Hence it's the user's responsibilty to
+ packet filter it out, or implement conntrack/NAT for that
+ protocol. 8) --RR */
+ if (!ct) {
+ /* Exception: ICMP redirect to new connection (not in
+ hash table yet). We must not let this through, in
+ case we're doing NAT to the same network. */
+ if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
+ struct icmphdr _hdr, *hp;
+
+ hp = skb_header_pointer(*pskb,
+ (*pskb)->nh.iph->ihl*4,
+ sizeof(_hdr), &_hdr);
+ if (hp != NULL &&
+ hp->type == ICMP_REDIRECT)
+ return NF_DROP;
+ }
+ return NF_ACCEPT;
+ }
+
+ /* Don't try to NAT if this packet is not conntracked */
+ if (ct == &nf_conntrack_untracked)
+ return NF_ACCEPT;
+
+ nat = nfct_nat(ct);
+ if (!nat)
+ return NF_DROP;
+
+ switch (ctinfo) {
+ case IP_CT_RELATED:
+ case IP_CT_RELATED+IP_CT_IS_REPLY:
+ if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
+ if (!nf_nat_icmp_reply_translation(ct, ctinfo,
+ hooknum, pskb))
+ return NF_DROP;
+ else
+ return NF_ACCEPT;
+ }
+ /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */
+ case IP_CT_NEW:
+ info = &nat->info;
+
+ /* Seen it before? This can happen for loopback, retrans,
+ or local packets.. */
+ if (!nf_nat_initialized(ct, maniptype)) {
+ unsigned int ret;
+
+ if (unlikely(nf_ct_is_confirmed(ct)))
+ /* NAT module was loaded late */
+ ret = alloc_null_binding_confirmed(ct, info,
+ hooknum);
+ else if (hooknum == NF_IP_LOCAL_IN)
+ /* LOCAL_IN hook doesn't have a chain! */
+ ret = alloc_null_binding(ct, info, hooknum);
+ else
+ ret = nf_nat_rule_find(pskb, hooknum, in, out,
+ ct, info);
+
+ if (ret != NF_ACCEPT) {
+ return ret;
+ }
+ } else
+ DEBUGP("Already setup manip %s for ct %p\n",
+ maniptype == IP_NAT_MANIP_SRC ? "SRC" : "DST",
+ ct);
+ break;
+
+ default:
+ /* ESTABLISHED */
+ NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED ||
+ ctinfo == (IP_CT_ESTABLISHED+IP_CT_IS_REPLY));
+ info = &nat->info;
+ }
+
+ NF_CT_ASSERT(info);
+ return nf_nat_packet(ct, ctinfo, hooknum, pskb);
+}
+
+static unsigned int
+nf_nat_in(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ unsigned int ret;
+ __be32 daddr = (*pskb)->nh.iph->daddr;
+
+ ret = nf_nat_fn(hooknum, pskb, in, out, okfn);
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ daddr != (*pskb)->nh.iph->daddr) {
+ dst_release((*pskb)->dst);
+ (*pskb)->dst = NULL;
+ }
+ return ret;
+}
+
+static unsigned int
+nf_nat_out(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+#ifdef CONFIG_XFRM
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+#endif
+ unsigned int ret;
+
+ /* root is playing with raw sockets. */
+ if ((*pskb)->len < sizeof(struct iphdr) ||
+ (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
+ return NF_ACCEPT;
+
+ ret = nf_nat_fn(hooknum, pskb, in, out, okfn);
+#ifdef CONFIG_XFRM
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ (ct = nf_ct_get(*pskb, &ctinfo)) != NULL) {
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+ if (ct->tuplehash[dir].tuple.src.u3.ip !=
+ ct->tuplehash[!dir].tuple.dst.u3.ip
+ || ct->tuplehash[dir].tuple.src.u.all !=
+ ct->tuplehash[!dir].tuple.dst.u.all
+ )
+ return ip_xfrm_me_harder(pskb) == 0 ? ret : NF_DROP;
+ }
+#endif
+ return ret;
+}
+
+static unsigned int
+nf_nat_local_fn(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+ unsigned int ret;
+
+ /* root is playing with raw sockets. */
+ if ((*pskb)->len < sizeof(struct iphdr) ||
+ (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
+ return NF_ACCEPT;
+
+ ret = nf_nat_fn(hooknum, pskb, in, out, okfn);
+ if (ret != NF_DROP && ret != NF_STOLEN &&
+ (ct = nf_ct_get(*pskb, &ctinfo)) != NULL) {
+ enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+ if (ct->tuplehash[dir].tuple.dst.u3.ip !=
+ ct->tuplehash[!dir].tuple.src.u3.ip
+#ifdef CONFIG_XFRM
+ || ct->tuplehash[dir].tuple.dst.u.all !=
+ ct->tuplehash[!dir].tuple.src.u.all
+#endif
+ )
+ if (ip_route_me_harder(pskb, RTN_UNSPEC))
+ ret = NF_DROP;
+ }
+ return ret;
+}
+
+static unsigned int
+nf_nat_adjust(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ struct nf_conn *ct;
+ enum ip_conntrack_info ctinfo;
+
+ ct = nf_ct_get(*pskb, &ctinfo);
+ if (ct && test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) {
+ DEBUGP("nf_nat_standalone: adjusting sequence number\n");
+ if (!nf_nat_seq_adjust(pskb, ct, ctinfo))
+ return NF_DROP;
+ }
+ return NF_ACCEPT;
+}
+
+/* We must be after connection tracking and before packet filtering. */
+
+static struct nf_hook_ops nf_nat_ops[] = {
+ /* Before packet filtering, change destination */
+ {
+ .hook = nf_nat_in,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_PRE_ROUTING,
+ .priority = NF_IP_PRI_NAT_DST,
+ },
+ /* After packet filtering, change source */
+ {
+ .hook = nf_nat_out,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_POST_ROUTING,
+ .priority = NF_IP_PRI_NAT_SRC,
+ },
+ /* After conntrack, adjust sequence number */
+ {
+ .hook = nf_nat_adjust,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_POST_ROUTING,
+ .priority = NF_IP_PRI_NAT_SEQ_ADJUST,
+ },
+ /* Before packet filtering, change destination */
+ {
+ .hook = nf_nat_local_fn,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_OUT,
+ .priority = NF_IP_PRI_NAT_DST,
+ },
+ /* After packet filtering, change source */
+ {
+ .hook = nf_nat_fn,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_IN,
+ .priority = NF_IP_PRI_NAT_SRC,
+ },
+ /* After conntrack, adjust sequence number */
+ {
+ .hook = nf_nat_adjust,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_IN,
+ .priority = NF_IP_PRI_NAT_SEQ_ADJUST,
+ },
+};
+
+static int __init nf_nat_standalone_init(void)
+{
+ int size, ret = 0;
+
+ need_conntrack();
+
+ size = ALIGN(sizeof(struct nf_conn), __alignof__(struct nf_conn_nat)) +
+ sizeof(struct nf_conn_nat);
+ ret = nf_conntrack_register_cache(NF_CT_F_NAT, "nf_nat:base", size);
+ if (ret < 0) {
+ printk(KERN_ERR "nf_nat_init: Unable to create slab cache\n");
+ return ret;
+ }
+
+ size = ALIGN(size, __alignof__(struct nf_conn_help)) +
+ sizeof(struct nf_conn_help);
+ ret = nf_conntrack_register_cache(NF_CT_F_NAT|NF_CT_F_HELP,
+ "nf_nat:help", size);
+ if (ret < 0) {
+ printk(KERN_ERR "nf_nat_init: Unable to create slab cache\n");
+ goto cleanup_register_cache;
+ }
+#ifdef CONFIG_XFRM
+ BUG_ON(ip_nat_decode_session != NULL);
+ ip_nat_decode_session = nat_decode_session;
+#endif
+ ret = nf_nat_rule_init();
+ if (ret < 0) {
+ printk("nf_nat_init: can't setup rules.\n");
+ goto cleanup_decode_session;
+ }
+ ret = nf_register_hooks(nf_nat_ops, ARRAY_SIZE(nf_nat_ops));
+ if (ret < 0) {
+ printk("nf_nat_init: can't register hooks.\n");
+ goto cleanup_rule_init;
+ }
+ nf_nat_module_is_loaded = 1;
+ return ret;
+
+ cleanup_rule_init:
+ nf_nat_rule_cleanup();
+ cleanup_decode_session:
+#ifdef CONFIG_XFRM
+ ip_nat_decode_session = NULL;
+ synchronize_net();
+#endif
+ nf_conntrack_unregister_cache(NF_CT_F_NAT|NF_CT_F_HELP);
+ cleanup_register_cache:
+ nf_conntrack_unregister_cache(NF_CT_F_NAT);
+ return ret;
+}
+
+static void __exit nf_nat_standalone_fini(void)
+{
+ nf_unregister_hooks(nf_nat_ops, ARRAY_SIZE(nf_nat_ops));
+ nf_nat_rule_cleanup();
+ nf_nat_module_is_loaded = 0;
+#ifdef CONFIG_XFRM
+ ip_nat_decode_session = NULL;
+ synchronize_net();
+#endif
+ /* Conntrack caches are unregistered in nf_conntrack_cleanup */
+}
+
+module_init(nf_nat_standalone_init);
+module_exit(nf_nat_standalone_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat");
/* FIXME: protect helper list per RCU */
read_lock_bh(&nf_conntrack_lock);
helper = __nf_ct_helper_find(repl);
- if (helper)
+ /* NAT might want to assign a helper later */
+ if (helper || features & NF_CT_F_NAT)
features |= NF_CT_F_HELP;
read_unlock_bh(&nf_conntrack_lock);
orig->dst.protonum));
}
+/* Alter reply tuple (maybe alter helper). This is for NAT, and is
+ implicitly racy: see __nf_conntrack_confirm */
+void nf_conntrack_alter_reply(struct nf_conn *ct,
+ const struct nf_conntrack_tuple *newreply)
+{
+ struct nf_conn_help *help = nfct_help(ct);
+
+ write_lock_bh(&nf_conntrack_lock);
+ /* Should be unconfirmed, so not in hash table yet */
+ NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
+
+ DEBUGP("Altering reply tuple of %p to ", ct);
+ NF_CT_DUMP_TUPLE(newreply);
+
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
+ if (!ct->master && help && help->expecting == 0)
+ help->helper = __nf_ct_helper_find(newreply);
+ write_unlock_bh(&nf_conntrack_lock);
+}
+
/* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
void __nf_ct_refresh_acct(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
-#include <linux/netfilter_ipv4/ip_nat_protocol.h>
+#include <net/netfilter/nf_conntrack_tuple.h>
+#ifdef CONFIG_NF_NAT_NEEDED
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#endif
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
restart:
list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) {
h = (struct nf_conntrack_tuple_hash *) i;
- if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
+ if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
continue;
ct = nf_ct_tuplehash_to_ctrack(h);
/* Dump entries of a given L3 protocol number.
return 0;
}
-#ifdef CONFIG_IP_NF_NAT_NEEDED
+#ifdef CONFIG_NF_NAT_NEEDED
static const size_t cta_min_protonat[CTA_PROTONAT_MAX] = {
[CTA_PROTONAT_PORT_MIN-1] = sizeof(u_int16_t),
[CTA_PROTONAT_PORT_MAX-1] = sizeof(u_int16_t),
};
-static int ctnetlink_parse_nat_proto(struct nfattr *attr,
+static int nfnetlink_parse_nat_proto(struct nfattr *attr,
const struct nf_conn *ct,
- struct ip_nat_range *range)
+ struct nf_nat_range *range)
{
struct nfattr *tb[CTA_PROTONAT_MAX];
- struct ip_nat_protocol *npt;
+ struct nf_nat_protocol *npt;
nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr);
if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))
return -EINVAL;
- npt = ip_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
+ npt = nf_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
if (!npt->nfattr_to_range) {
- ip_nat_proto_put(npt);
+ nf_nat_proto_put(npt);
return 0;
}
if (npt->nfattr_to_range(tb, range) > 0)
range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
- ip_nat_proto_put(npt);
+ nf_nat_proto_put(npt);
return 0;
}
};
static inline int
-ctnetlink_parse_nat(struct nfattr *nat,
- const struct nf_conn *ct, struct ip_nat_range *range)
+nfnetlink_parse_nat(struct nfattr *nat,
+ const struct nf_conn *ct, struct nf_nat_range *range)
{
struct nfattr *tb[CTA_NAT_MAX];
int err;
if (!tb[CTA_NAT_PROTO-1])
return 0;
- err = ctnetlink_parse_nat_proto(tb[CTA_NAT_PROTO-1], ct, range);
+ err = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO-1], ct, range);
if (err < 0)
return err;
return -EINVAL;
if (cda[CTA_NAT_SRC-1] || cda[CTA_NAT_DST-1]) {
-#ifndef CONFIG_IP_NF_NAT_NEEDED
+#ifndef CONFIG_NF_NAT_NEEDED
return -EINVAL;
#else
- struct ip_nat_range range;
+ struct nf_nat_range range;
if (cda[CTA_NAT_DST-1]) {
- if (ctnetlink_parse_nat(cda[CTA_NAT_DST-1], ct,
+ if (nfnetlink_parse_nat(cda[CTA_NAT_DST-1], ct,
&range) < 0)
return -EINVAL;
- if (ip_nat_initialized(ct,
+ if (nf_nat_initialized(ct,
HOOK2MANIP(NF_IP_PRE_ROUTING)))
return -EEXIST;
- ip_nat_setup_info(ct, &range, hooknum);
+ nf_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING);
}
if (cda[CTA_NAT_SRC-1]) {
- if (ctnetlink_parse_nat(cda[CTA_NAT_SRC-1], ct,
+ if (nfnetlink_parse_nat(cda[CTA_NAT_SRC-1], ct,
&range) < 0)
return -EINVAL;
- if (ip_nat_initialized(ct,
+ if (nf_nat_initialized(ct,
HOOK2MANIP(NF_IP_POST_ROUTING)))
return -EEXIST;
- ip_nat_setup_info(ct, &range, hooknum);
+ nf_nat_setup_info(ct, &range, NF_IP_POST_ROUTING);
}
#endif
}
/* Be careful here, modifying NAT bits can screw up things,
* so don't let users modify them directly if they don't pass
- * ip_nat_range. */
+ * nf_nat_range. */
ct->status |= status & ~(IPS_NAT_DONE_MASK | IPS_NAT_MASK);
return 0;
}
return res;
}
-#ifdef CONFIG_IP_NF_NAT_NEEDED
+#ifdef CONFIG_NF_NAT_NEEDED
/* Update sender->td_end after NAT successfully mangled the packet */
/* Caller must linearize skb at tcp header. */
void nf_conntrack_tcp_update(struct sk_buff *skb,
EXPORT_SYMBOL(nf_conntrack_hash);
EXPORT_SYMBOL(nf_conntrack_untracked);
EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
-#ifdef CONFIG_IP_NF_NAT_NEEDED
+#ifdef CONFIG_NF_NAT_NEEDED
EXPORT_SYMBOL(nf_conntrack_tcp_update);
+EXPORT_SYMBOL(nf_conntrack_register_cache);
+EXPORT_SYMBOL(nf_conntrack_unregister_cache);
+EXPORT_SYMBOL(nf_conntrack_alter_reply);
#endif
EXPORT_SYMBOL(__nf_conntrack_confirm);
EXPORT_SYMBOL(nf_ct_get_tuple);
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