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