121 lines
3.3 KiB
C
121 lines
3.3 KiB
C
/*
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* Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Based on Rusty Russell's IPv6 MASQUERADE target. Development of IPv6
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* NAT funded by Astaro.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/atomic.h>
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#include <linux/netdevice.h>
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#include <linux/ipv6.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/addrconf.h>
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#include <net/ipv6.h>
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#include <net/netfilter/ipv6/nf_nat_masquerade.h>
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unsigned int
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nf_nat_masquerade_ipv6(struct sk_buff *skb, const struct nf_nat_range *range,
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const struct net_device *out)
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{
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enum ip_conntrack_info ctinfo;
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struct in6_addr src;
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struct nf_conn *ct;
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struct nf_nat_range newrange;
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ct = nf_ct_get(skb, &ctinfo);
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NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED ||
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ctinfo == IP_CT_RELATED_REPLY));
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if (ipv6_dev_get_saddr(dev_net(out), out,
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&ipv6_hdr(skb)->daddr, 0, &src) < 0)
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return NF_DROP;
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nfct_nat(ct)->masq_index = out->ifindex;
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newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS;
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newrange.min_addr.in6 = src;
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newrange.max_addr.in6 = src;
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newrange.min_proto = range->min_proto;
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newrange.max_proto = range->max_proto;
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return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC);
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}
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EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6);
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static int device_cmp(struct nf_conn *ct, void *ifindex)
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{
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const struct nf_conn_nat *nat = nfct_nat(ct);
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if (!nat)
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return 0;
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if (nf_ct_l3num(ct) != NFPROTO_IPV6)
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return 0;
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return nat->masq_index == (int)(long)ifindex;
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}
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static int masq_device_event(struct notifier_block *this,
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unsigned long event, void *ptr)
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{
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const struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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struct net *net = dev_net(dev);
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if (event == NETDEV_DOWN)
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nf_ct_iterate_cleanup(net, device_cmp,
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(void *)(long)dev->ifindex, 0, 0);
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return NOTIFY_DONE;
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}
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static struct notifier_block masq_dev_notifier = {
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.notifier_call = masq_device_event,
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};
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static int masq_inet_event(struct notifier_block *this,
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unsigned long event, void *ptr)
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{
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struct inet6_ifaddr *ifa = ptr;
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struct netdev_notifier_info info;
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netdev_notifier_info_init(&info, ifa->idev->dev);
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return masq_device_event(this, event, &info);
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}
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static struct notifier_block masq_inet_notifier = {
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.notifier_call = masq_inet_event,
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};
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static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);
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void nf_nat_masquerade_ipv6_register_notifier(void)
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{
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/* check if the notifier is already set */
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if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
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return;
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register_netdevice_notifier(&masq_dev_notifier);
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register_inet6addr_notifier(&masq_inet_notifier);
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}
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EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier);
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void nf_nat_masquerade_ipv6_unregister_notifier(void)
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{
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/* check if the notifier still has clients */
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if (atomic_dec_return(&masquerade_notifier_refcount) > 0)
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return;
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unregister_inet6addr_notifier(&masq_inet_notifier);
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unregister_netdevice_notifier(&masq_dev_notifier);
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}
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EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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