/*
* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
* (C) 2011 Patrick McHardy <kaber@trash.net>
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/skbuff.h>
#include <linux/gfp.h>
#include <net/xfrm.h>
#include <linux/jhash.h>
#include <linux/rtnetlink.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_l3proto.h>
#include <net/netfilter/nf_nat_l4proto.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_seqadj.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <linux/netfilter/nf_nat.h>
#include "nf_internals.h"
static spinlock_t nf_nat_locks[CONNTRACK_LOCKS];
static DEFINE_MUTEX(nf_nat_proto_mutex);
static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
__read_mostly;
static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
__read_mostly;
static unsigned int nat_net_id __read_mostly;
static struct hlist_head *nf_nat_bysource __read_mostly;
static unsigned int nf_nat_htable_size __read_mostly;
static unsigned int nf_nat_hash_rnd __read_mostly;
struct nf_nat_lookup_hook_priv {
struct nf_hook_entries __rcu *entries;
struct rcu_head rcu_head;
};
struct nf_nat_hooks_net {
struct nf_hook_ops *nat_hook_ops;
unsigned int users;
};
struct nat_net {
struct nf_nat_hooks_net nat_proto_net[NFPROTO_NUMPROTO];
};
inline const struct nf_nat_l3proto *
__nf_nat_l3proto_find(u8 family)
{
return rcu_dereference(nf_nat_l3protos[family]);
}
inline const struct nf_nat_l4proto *
__nf_nat_l4proto_find(u8 family, u8 protonum)
{
return rcu_dereference(nf_nat_l4protos[family][protonum]);
}
EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
#ifdef CONFIG_XFRM
static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
{
const struct nf_nat_l3proto *l3proto;
const struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
enum ip_conntrack_dir dir;
unsigned long statusbit;
u8 family;
ct = nf_ct_get(skb, &ctinfo);
if (ct == NULL)
return;
family = nf_ct_l3num(ct);
l3proto = __nf_nat_l3proto_find(family);
if (l3proto == NULL)
return;
dir = CTINFO2DIR(ctinfo);
if (dir == IP_CT_DIR_ORIGINAL)
statusbit = IPS_DST_NAT;
else
statusbit = IPS_SRC_NAT;
l3proto->decode_session(skb, ct, dir, statusbit, fl);
}
int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
{
struct flowi fl;
unsigned int hh_len;
struct dst_entry *dst;
struct sock *sk = skb->sk;
int err;
err = xfrm_decode_session(skb, &fl, family);
if (err < 0)
return err;
dst = skb_dst(skb);
if (dst->xfrm)
dst = ((struct xfrm_dst *)dst)->route;
dst_hold(dst);
if (sk && !net_eq(net, sock_net(sk)))
sk = NULL;
dst = xfrm_lookup(net, dst, &fl, sk, 0);
if (IS_ERR(dst))
return PTR_ERR(dst);
skb_dst_drop(skb);
skb_dst_set(skb, dst);