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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
8b13eddf AB |
2 | /* |
3 | * (C) 1999-2001 Paul `Rusty' Russell | |
4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> | |
5 | * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> | |
6 | * | |
8b13eddf AB |
7 | * Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6 |
8 | * NAT funded by Astaro. | |
9 | */ | |
10 | ||
11 | #include <linux/if.h> | |
12 | #include <linux/inetdevice.h> | |
13 | #include <linux/ip.h> | |
14 | #include <linux/kernel.h> | |
8b13eddf AB |
15 | #include <linux/netdevice.h> |
16 | #include <linux/netfilter.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/netfilter_ipv4.h> | |
b59eaf9e | 19 | #include <linux/netfilter_ipv6.h> |
8b13eddf AB |
20 | #include <linux/netfilter/x_tables.h> |
21 | #include <net/addrconf.h> | |
22 | #include <net/checksum.h> | |
23 | #include <net/protocol.h> | |
24 | #include <net/netfilter/nf_nat.h> | |
b59eaf9e | 25 | #include <net/netfilter/nf_nat_redirect.h> |
8b13eddf AB |
26 | |
27 | unsigned int | |
28 | nf_nat_redirect_ipv4(struct sk_buff *skb, | |
29 | const struct nf_nat_ipv4_multi_range_compat *mr, | |
30 | unsigned int hooknum) | |
31 | { | |
32 | struct nf_conn *ct; | |
33 | enum ip_conntrack_info ctinfo; | |
34 | __be32 newdst; | |
2eb0f624 | 35 | struct nf_nat_range2 newrange; |
8b13eddf | 36 | |
44d6e2f2 VR |
37 | WARN_ON(hooknum != NF_INET_PRE_ROUTING && |
38 | hooknum != NF_INET_LOCAL_OUT); | |
8b13eddf AB |
39 | |
40 | ct = nf_ct_get(skb, &ctinfo); | |
44d6e2f2 | 41 | WARN_ON(!(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED))); |
8b13eddf AB |
42 | |
43 | /* Local packets: make them go to loopback */ | |
44 | if (hooknum == NF_INET_LOCAL_OUT) { | |
45 | newdst = htonl(0x7F000001); | |
46 | } else { | |
2638eb8b | 47 | const struct in_device *indev; |
8b13eddf AB |
48 | |
49 | newdst = 0; | |
50 | ||
8b13eddf | 51 | indev = __in_dev_get_rcu(skb->dev); |
2638eb8b FW |
52 | if (indev) { |
53 | const struct in_ifaddr *ifa; | |
54 | ||
55 | ifa = rcu_dereference(indev->ifa_list); | |
56 | if (ifa) | |
57 | newdst = ifa->ifa_local; | |
8b13eddf | 58 | } |
8b13eddf AB |
59 | |
60 | if (!newdst) | |
61 | return NF_DROP; | |
62 | } | |
63 | ||
64 | /* Transfer from original range. */ | |
65 | memset(&newrange.min_addr, 0, sizeof(newrange.min_addr)); | |
66 | memset(&newrange.max_addr, 0, sizeof(newrange.max_addr)); | |
67 | newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS; | |
68 | newrange.min_addr.ip = newdst; | |
69 | newrange.max_addr.ip = newdst; | |
70 | newrange.min_proto = mr->range[0].min; | |
71 | newrange.max_proto = mr->range[0].max; | |
72 | ||
73 | /* Hand modified range to generic setup. */ | |
74 | return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST); | |
75 | } | |
76 | EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4); | |
77 | ||
b59eaf9e PNA |
78 | static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT; |
79 | ||
80 | unsigned int | |
2eb0f624 | 81 | nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range2 *range, |
b59eaf9e PNA |
82 | unsigned int hooknum) |
83 | { | |
2eb0f624 | 84 | struct nf_nat_range2 newrange; |
b59eaf9e PNA |
85 | struct in6_addr newdst; |
86 | enum ip_conntrack_info ctinfo; | |
87 | struct nf_conn *ct; | |
88 | ||
89 | ct = nf_ct_get(skb, &ctinfo); | |
90 | if (hooknum == NF_INET_LOCAL_OUT) { | |
91 | newdst = loopback_addr; | |
92 | } else { | |
93 | struct inet6_dev *idev; | |
94 | struct inet6_ifaddr *ifa; | |
95 | bool addr = false; | |
96 | ||
b59eaf9e PNA |
97 | idev = __in6_dev_get(skb->dev); |
98 | if (idev != NULL) { | |
0c7930e5 | 99 | read_lock_bh(&idev->lock); |
b59eaf9e PNA |
100 | list_for_each_entry(ifa, &idev->addr_list, if_list) { |
101 | newdst = ifa->addr; | |
102 | addr = true; | |
103 | break; | |
104 | } | |
0c7930e5 | 105 | read_unlock_bh(&idev->lock); |
b59eaf9e | 106 | } |
b59eaf9e PNA |
107 | |
108 | if (!addr) | |
109 | return NF_DROP; | |
110 | } | |
111 | ||
112 | newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; | |
113 | newrange.min_addr.in6 = newdst; | |
114 | newrange.max_addr.in6 = newdst; | |
115 | newrange.min_proto = range->min_proto; | |
116 | newrange.max_proto = range->max_proto; | |
117 | ||
118 | return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST); | |
119 | } | |
120 | EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6); |