Arturo Borrero | be6b635 | 2014-09-04 14:06:49 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * Based on Rusty Russell's IPv6 MASQUERADE target. Development of IPv6 |
| 9 | * NAT funded by Astaro. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/atomic.h> |
| 15 | #include <linux/netdevice.h> |
| 16 | #include <linux/ipv6.h> |
| 17 | #include <linux/netfilter.h> |
| 18 | #include <linux/netfilter_ipv6.h> |
| 19 | #include <net/netfilter/nf_nat.h> |
| 20 | #include <net/addrconf.h> |
| 21 | #include <net/ipv6.h> |
| 22 | #include <net/netfilter/ipv6/nf_nat_masquerade.h> |
| 23 | |
| 24 | unsigned int |
| 25 | nf_nat_masquerade_ipv6(struct sk_buff *skb, const struct nf_nat_range *range, |
| 26 | const struct net_device *out) |
| 27 | { |
| 28 | enum ip_conntrack_info ctinfo; |
| 29 | struct in6_addr src; |
| 30 | struct nf_conn *ct; |
| 31 | struct nf_nat_range newrange; |
| 32 | |
| 33 | ct = nf_ct_get(skb, &ctinfo); |
| 34 | NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || |
| 35 | ctinfo == IP_CT_RELATED_REPLY)); |
| 36 | |
| 37 | if (ipv6_dev_get_saddr(dev_net(out), out, |
| 38 | &ipv6_hdr(skb)->daddr, 0, &src) < 0) |
| 39 | return NF_DROP; |
| 40 | |
| 41 | nfct_nat(ct)->masq_index = out->ifindex; |
| 42 | |
| 43 | newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; |
| 44 | newrange.min_addr.in6 = src; |
| 45 | newrange.max_addr.in6 = src; |
| 46 | newrange.min_proto = range->min_proto; |
| 47 | newrange.max_proto = range->max_proto; |
| 48 | |
| 49 | return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC); |
| 50 | } |
| 51 | EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6); |
| 52 | |
| 53 | static int device_cmp(struct nf_conn *ct, void *ifindex) |
| 54 | { |
| 55 | const struct nf_conn_nat *nat = nfct_nat(ct); |
| 56 | |
| 57 | if (!nat) |
| 58 | return 0; |
| 59 | if (nf_ct_l3num(ct) != NFPROTO_IPV6) |
| 60 | return 0; |
| 61 | return nat->masq_index == (int)(long)ifindex; |
| 62 | } |
| 63 | |
| 64 | static int masq_device_event(struct notifier_block *this, |
| 65 | unsigned long event, void *ptr) |
| 66 | { |
| 67 | const struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
| 68 | struct net *net = dev_net(dev); |
| 69 | |
| 70 | if (event == NETDEV_DOWN) |
| 71 | nf_ct_iterate_cleanup(net, device_cmp, |
| 72 | (void *)(long)dev->ifindex, 0, 0); |
| 73 | |
| 74 | return NOTIFY_DONE; |
| 75 | } |
| 76 | |
| 77 | static struct notifier_block masq_dev_notifier = { |
| 78 | .notifier_call = masq_device_event, |
| 79 | }; |
| 80 | |
| 81 | static int masq_inet_event(struct notifier_block *this, |
| 82 | unsigned long event, void *ptr) |
| 83 | { |
| 84 | struct inet6_ifaddr *ifa = ptr; |
| 85 | struct netdev_notifier_info info; |
| 86 | |
| 87 | netdev_notifier_info_init(&info, ifa->idev->dev); |
| 88 | return masq_device_event(this, event, &info); |
| 89 | } |
| 90 | |
| 91 | static struct notifier_block masq_inet_notifier = { |
| 92 | .notifier_call = masq_inet_event, |
| 93 | }; |
| 94 | |
| 95 | static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0); |
| 96 | |
| 97 | void nf_nat_masquerade_ipv6_register_notifier(void) |
| 98 | { |
| 99 | /* check if the notifier is already set */ |
| 100 | if (atomic_inc_return(&masquerade_notifier_refcount) > 1) |
| 101 | return; |
| 102 | |
| 103 | register_netdevice_notifier(&masq_dev_notifier); |
| 104 | register_inet6addr_notifier(&masq_inet_notifier); |
| 105 | } |
| 106 | EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier); |
| 107 | |
| 108 | void nf_nat_masquerade_ipv6_unregister_notifier(void) |
| 109 | { |
| 110 | /* check if the notifier still has clients */ |
| 111 | if (atomic_dec_return(&masquerade_notifier_refcount) > 0) |
| 112 | return; |
| 113 | |
| 114 | unregister_inet6addr_notifier(&masq_inet_notifier); |
| 115 | unregister_netdevice_notifier(&masq_dev_notifier); |
| 116 | } |
| 117 | EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier); |
| 118 | |
| 119 | MODULE_LICENSE("GPL"); |
| 120 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |