| /* |
| * (C) 1999-2001 Paul `Rusty' Russell |
| * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| * 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 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/module.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_range 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 { |
| struct in_device *indev; |
| struct in_ifaddr *ifa; |
| |
| newdst = 0; |
| |
| rcu_read_lock(); |
| indev = __in_dev_get_rcu(skb->dev); |
| if (indev && indev->ifa_list) { |
| ifa = indev->ifa_list; |
| newdst = ifa->ifa_local; |
| } |
| rcu_read_unlock(); |
| |
| 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_range *range, |
| unsigned int hooknum) |
| { |
| struct nf_nat_range 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; |
| |
| rcu_read_lock(); |
| 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); |
| } |
| rcu_read_unlock(); |
| |
| 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); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |