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Commit 5b1158e9 authored by Jozsef Kadlecsik's avatar Jozsef Kadlecsik Committed by David S. Miller
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[NETFILTER]: Add NAT support for nf_conntrack 

Add NAT support for nf_conntrack. Joint work of Jozsef Kadlecsik,
Yasuyuki Kozakai, Martin Josefsson and myself.
Signed-off-by: default avatarJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d2483dde
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Showing with 2667 additions and 59 deletions
include/linux/netfilter.h
View file @ 5b1158e9
......@@ -357,7 +357,7 @@ extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
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)
......
include/net/netfilter/ipv4/nf_conntrack_ipv4.h
View file @ 5b1158e9
......@@ -9,29 +9,23 @@
#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 *
......
include/net/netfilter/nf_conntrack.h
View file @ 5b1158e9
......@@ -264,18 +264,45 @@ nf_conntrack_unregister_cache(u_int32_t features);
/* 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 */
include/net/netfilter/nf_conntrack_expect.h
View file @ 5b1158e9
......@@ -43,7 +43,7 @@ struct nf_conntrack_expect
#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
......
include/net/netfilter/nf_nat.h 0 → 100644
View file @ 5b1158e9
#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
include/net/netfilter/nf_nat_core.h 0 → 100644
View file @ 5b1158e9
#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 */
include/net/netfilter/nf_nat_helper.h 0 → 100644
View file @ 5b1158e9
#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
include/net/netfilter/nf_nat_protocol.h 0 → 100644
View file @ 5b1158e9
/* 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*/
include/net/netfilter/nf_nat_rule.h 0 → 100644
View file @ 5b1158e9
#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 */
net/ipv4/netfilter/Kconfig
View file @ 5b1158e9
......@@ -6,7 +6,7 @@ menu "IP: Netfilter Configuration"
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
......@@ -387,7 +387,7 @@ config IP_NF_TARGET_TCPMSS
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
......@@ -398,14 +398,30 @@ config IP_NF_NAT
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
......@@ -417,7 +433,7 @@ config IP_NF_TARGET_MASQUERADE
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
......@@ -428,7 +444,7 @@ config IP_NF_TARGET_REDIRECT
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
......@@ -439,7 +455,7 @@ config IP_NF_TARGET_NETMAP
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.
......
net/ipv4/netfilter/Makefile
View file @ 5b1158e9
......@@ -5,7 +5,12 @@
# 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 ($(CONFIG_NF_NAT),)
iptable_nat-objs := nf_nat_rule.o nf_nat_standalone.o
else
iptable_nat-objs := ip_nat_rule.o ip_nat_standalone.o
endif
ip_conntrack_pptp-objs := ip_conntrack_helper_pptp.o ip_conntrack_proto_gre.o
ip_nat_pptp-objs := ip_nat_helper_pptp.o ip_nat_proto_gre.o
......@@ -16,6 +21,7 @@ ip_nat_h323-objs := ip_nat_helper_h323.o
# connection tracking
obj-$(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-$(CONFIG_IP_NF_CONNTRACK_NETLINK) += ip_conntrack_netlink.o
......@@ -50,6 +56,7 @@ obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.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
......
net/ipv4/netfilter/ip_nat_standalone.c
View file @ 5b1158e9
......@@ -44,12 +44,6 @@
#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)
{
......
net/ipv4/netfilter/ipt_MASQUERADE.c
View file @ 5b1158e9
......@@ -2,7 +2,7 @@
(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
......@@ -20,7 +20,11 @@
#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");
......@@ -65,23 +69,33 @@ masquerade_target(struct sk_buff **pskb,
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;
......@@ -93,7 +107,11 @@ masquerade_target(struct sk_buff **pskb,
}
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. */
......@@ -109,10 +127,17 @@ masquerade_target(struct sk_buff **pskb,
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;
......
net/ipv4/netfilter/ipt_NETMAP.c
View file @ 5b1158e9
......@@ -15,7 +15,11 @@
#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");
......
net/ipv4/netfilter/ipt_REDIRECT.c
View file @ 5b1158e9
/* 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
......@@ -18,7 +18,11 @@
#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>");
......
net/ipv4/netfilter/ipt_SAME.c
View file @ 5b1158e9
......@@ -34,7 +34,11 @@
#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");
......@@ -152,11 +156,17 @@ same_target(struct sk_buff **pskb,
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]);
......
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
View file @ 5b1158e9
......@@ -111,10 +111,10 @@ ipv4_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
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;
......@@ -532,3 +532,6 @@ module_init(nf_conntrack_l3proto_ipv4_init);
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
net/ipv4/netfilter/nf_nat_core.c 0 → 100644
View file @ 5b1158e9
/* 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);
net/ipv4/netfilter/nf_nat_helper.c 0 → 100644
View file @ 5b1158e9
/* 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);
net/ipv4/netfilter/nf_nat_proto_icmp.c 0 → 100644
View file @ 5b1158e9
/* (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
};
net/ipv4/netfilter/nf_nat_proto_tcp.c 0 → 100644
View file @ 5b1158e9
/* (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
};
net/ipv4/netfilter/nf_nat_proto_udp.c 0 → 100644
View file @ 5b1158e9
/* (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
};
net/ipv4/netfilter/nf_nat_proto_unknown.c 0 → 100644
View file @ 5b1158e9
/* 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,
};
net/ipv4/netfilter/nf_nat_rule.c 0 → 100644
View file @ 5b1158e9
/* (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);
}
net/ipv4/netfilter/nf_nat_standalone.c 0 → 100644
View file @ 5b1158e9
/* (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");
net/netfilter/nf_conntrack_core.c
View file @ 5b1158e9
......@@ -579,7 +579,8 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
/* 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);
......@@ -850,6 +851,26 @@ int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
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,
......
net/netfilter/nf_conntrack_netlink.c
View file @ 5b1158e9
......@@ -39,7 +39,11 @@
#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>
......@@ -430,7 +434,7 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
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.
......@@ -556,28 +560,28 @@ ctnetlink_parse_tuple(struct nfattr *cda[], struct nf_conntrack_tuple *tuple,
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;
}
......@@ -585,7 +589,7 @@ static int ctnetlink_parse_nat_proto(struct nfattr *attr,
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;
}
......@@ -596,8 +600,8 @@ static const size_t cta_min_nat[CTA_NAT_MAX] = {
};
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;
......@@ -623,7 +627,7 @@ ctnetlink_parse_nat(struct nfattr *nat,
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;
......@@ -798,35 +802,35 @@ ctnetlink_change_status(struct nf_conn *ct, struct nfattr *cda[])
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;
}
......
net/netfilter/nf_conntrack_proto_tcp.c
View file @ 5b1158e9
......@@ -730,7 +730,7 @@ static int tcp_in_window(struct ip_ct_tcp *state,
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,
......
net/netfilter/nf_conntrack_standalone.c
View file @ 5b1158e9
......@@ -530,8 +530,11 @@ EXPORT_SYMBOL(nf_conntrack_lock);
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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