swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: a1b8638ba1320e6684aa98233c15255eb803fac7 authored by Linus Torvalds on 27 September 2020, 21:38:10 UTC
Linux 5.9-rc7
Linux 5.9-rc7
Tip revision: a1b8638
nf_nat_redirect.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
* Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
*
* Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6
* NAT funded by Astaro.
*/
#include <linux/if.h>
#include <linux/inetdevice.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/types.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/x_tables.h>
#include <net/addrconf.h>
#include <net/checksum.h>
#include <net/protocol.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_redirect.h>
unsigned int
nf_nat_redirect_ipv4(struct sk_buff *skb,
const struct nf_nat_ipv4_multi_range_compat *mr,
unsigned int hooknum)
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
__be32 newdst;
struct nf_nat_range2 newrange;
WARN_ON(hooknum != NF_INET_PRE_ROUTING &&
hooknum != NF_INET_LOCAL_OUT);
ct = nf_ct_get(skb, &ctinfo);
WARN_ON(!(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)));
/* Local packets: make them go to loopback */
if (hooknum == NF_INET_LOCAL_OUT) {
newdst = htonl(0x7F000001);
} else {
const struct in_device *indev;
newdst = 0;
indev = __in_dev_get_rcu(skb->dev);
if (indev) {
const struct in_ifaddr *ifa;
ifa = rcu_dereference(indev->ifa_list);
if (ifa)
newdst = ifa->ifa_local;
}
if (!newdst)
return NF_DROP;
}
/* Transfer from original range. */
memset(&newrange.min_addr, 0, sizeof(newrange.min_addr));
memset(&newrange.max_addr, 0, sizeof(newrange.max_addr));
newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS;
newrange.min_addr.ip = newdst;
newrange.max_addr.ip = newdst;
newrange.min_proto = mr->range[0].min;
newrange.max_proto = mr->range[0].max;
/* Hand modified range to generic setup. */
return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
}
EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4);
static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT;
unsigned int
nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range,
unsigned int hooknum)
{
struct nf_nat_range2 newrange;
struct in6_addr newdst;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
ct = nf_ct_get(skb, &ctinfo);
if (hooknum == NF_INET_LOCAL_OUT) {
newdst = loopback_addr;
} else {
struct inet6_dev *idev;
struct inet6_ifaddr *ifa;
bool addr = false;
idev = __in6_dev_get(skb->dev);
if (idev != NULL) {
read_lock_bh(&idev->lock);
list_for_each_entry(ifa, &idev->addr_list, if_list) {
newdst = ifa->addr;
addr = true;
break;
}
read_unlock_bh(&idev->lock);
}
if (!addr)
return NF_DROP;
}
newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS;
newrange.min_addr.in6 = newdst;
newrange.max_addr.in6 = newdst;
newrange.min_proto = range->min_proto;
newrange.max_proto = range->max_proto;
return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST);
}
EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6);