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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6 | |
3 | * | |
4 | * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org> | |
5 | * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
1da177e4 LT |
10 | */ |
11 | #include <linux/module.h> | |
12 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
1da177e4 LT |
14 | |
15 | MODULE_LICENSE("GPL"); | |
16 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
17 | MODULE_DESCRIPTION("ip6tables mangle table"); | |
18 | ||
6e23ae2a PM |
19 | #define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \ |
20 | (1 << NF_INET_LOCAL_IN) | \ | |
21 | (1 << NF_INET_FORWARD) | \ | |
22 | (1 << NF_INET_LOCAL_OUT) | \ | |
23 | (1 << NF_INET_POST_ROUTING)) | |
1da177e4 | 24 | |
35aad0ff | 25 | static const struct xt_table packet_mangler = { |
1da177e4 LT |
26 | .name = "mangle", |
27 | .valid_hooks = MANGLE_VALID_HOOKS, | |
1da177e4 | 28 | .me = THIS_MODULE, |
f88e6a8a | 29 | .af = NFPROTO_IPV6, |
2b95efe7 | 30 | .priority = NF_IP6_PRI_MANGLE, |
1da177e4 LT |
31 | }; |
32 | ||
7dd1b8da | 33 | static unsigned int |
fa96a0e2 | 34 | ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out) |
1da177e4 | 35 | { |
1da177e4 LT |
36 | unsigned int ret; |
37 | struct in6_addr saddr, daddr; | |
38 | u_int8_t hop_limit; | |
82e91ffe | 39 | u_int32_t flowlabel, mark; |
1da177e4 LT |
40 | |
41 | #if 0 | |
42 | /* root is playing with raw sockets. */ | |
3666ed1c JP |
43 | if (skb->len < sizeof(struct iphdr) || |
44 | ip_hdrlen(skb) < sizeof(struct iphdr)) { | |
e87cc472 | 45 | net_warn_ratelimited("ip6t_hook: happy cracking\n"); |
1da177e4 LT |
46 | return NF_ACCEPT; |
47 | } | |
48 | #endif | |
49 | ||
82e91ffe | 50 | /* save source/dest address, mark, hoplimit, flowlabel, priority, */ |
3db05fea HX |
51 | memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr)); |
52 | memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr)); | |
53 | mark = skb->mark; | |
54 | hop_limit = ipv6_hdr(skb)->hop_limit; | |
1da177e4 LT |
55 | |
56 | /* flowlabel and prio (includes version, which shouldn't change either */ | |
3db05fea | 57 | flowlabel = *((u_int32_t *)ipv6_hdr(skb)); |
1da177e4 | 58 | |
fa96a0e2 | 59 | ret = ip6t_do_table(skb, NF_INET_LOCAL_OUT, NULL, out, |
7dd1b8da | 60 | dev_net(out)->ipv6.ip6table_mangle); |
1da177e4 | 61 | |
3666ed1c JP |
62 | if (ret != NF_DROP && ret != NF_STOLEN && |
63 | (memcmp(&ipv6_hdr(skb)->saddr, &saddr, sizeof(saddr)) || | |
64 | memcmp(&ipv6_hdr(skb)->daddr, &daddr, sizeof(daddr)) || | |
65 | skb->mark != mark || | |
b169f6db DM |
66 | ipv6_hdr(skb)->hop_limit != hop_limit || |
67 | flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) | |
3db05fea | 68 | return ip6_route_me_harder(skb) == 0 ? ret : NF_DROP; |
1da177e4 LT |
69 | |
70 | return ret; | |
71 | } | |
72 | ||
737535c5 JE |
73 | /* The work comes in here from netfilter.c. */ |
74 | static unsigned int | |
75 | ip6table_mangle_hook(unsigned int hook, struct sk_buff *skb, | |
76 | const struct net_device *in, const struct net_device *out, | |
77 | int (*okfn)(struct sk_buff *)) | |
78 | { | |
79 | if (hook == NF_INET_LOCAL_OUT) | |
fa96a0e2 | 80 | return ip6t_mangle_out(skb, out); |
b2907e50 AD |
81 | if (hook == NF_INET_POST_ROUTING) |
82 | return ip6t_do_table(skb, hook, in, out, | |
83 | dev_net(out)->ipv6.ip6table_mangle); | |
737535c5 JE |
84 | /* INPUT/FORWARD */ |
85 | return ip6t_do_table(skb, hook, in, out, | |
86 | dev_net(in)->ipv6.ip6table_mangle); | |
87 | } | |
88 | ||
2b95efe7 | 89 | static struct nf_hook_ops *mangle_ops __read_mostly; |
8280aa61 AD |
90 | static int __net_init ip6table_mangle_net_init(struct net *net) |
91 | { | |
e3eaa991 JE |
92 | struct ip6t_replace *repl; |
93 | ||
94 | repl = ip6t_alloc_initial_table(&packet_mangler); | |
95 | if (repl == NULL) | |
96 | return -ENOMEM; | |
8280aa61 | 97 | net->ipv6.ip6table_mangle = |
e3eaa991 JE |
98 | ip6t_register_table(net, &packet_mangler, repl); |
99 | kfree(repl); | |
8280aa61 AD |
100 | if (IS_ERR(net->ipv6.ip6table_mangle)) |
101 | return PTR_ERR(net->ipv6.ip6table_mangle); | |
102 | return 0; | |
103 | } | |
104 | ||
105 | static void __net_exit ip6table_mangle_net_exit(struct net *net) | |
106 | { | |
f54e9367 | 107 | ip6t_unregister_table(net, net->ipv6.ip6table_mangle); |
8280aa61 AD |
108 | } |
109 | ||
110 | static struct pernet_operations ip6table_mangle_net_ops = { | |
111 | .init = ip6table_mangle_net_init, | |
112 | .exit = ip6table_mangle_net_exit, | |
113 | }; | |
114 | ||
65b4b4e8 | 115 | static int __init ip6table_mangle_init(void) |
1da177e4 LT |
116 | { |
117 | int ret; | |
118 | ||
8280aa61 AD |
119 | ret = register_pernet_subsys(&ip6table_mangle_net_ops); |
120 | if (ret < 0) | |
121 | return ret; | |
1da177e4 LT |
122 | |
123 | /* Register hooks */ | |
2b95efe7 JE |
124 | mangle_ops = xt_hook_link(&packet_mangler, ip6table_mangle_hook); |
125 | if (IS_ERR(mangle_ops)) { | |
126 | ret = PTR_ERR(mangle_ops); | |
1da177e4 | 127 | goto cleanup_table; |
2b95efe7 | 128 | } |
1da177e4 | 129 | |
1da177e4 LT |
130 | return ret; |
131 | ||
1da177e4 | 132 | cleanup_table: |
8280aa61 | 133 | unregister_pernet_subsys(&ip6table_mangle_net_ops); |
1da177e4 LT |
134 | return ret; |
135 | } | |
136 | ||
65b4b4e8 | 137 | static void __exit ip6table_mangle_fini(void) |
1da177e4 | 138 | { |
2b95efe7 | 139 | xt_hook_unlink(&packet_mangler, mangle_ops); |
8280aa61 | 140 | unregister_pernet_subsys(&ip6table_mangle_net_ops); |
1da177e4 LT |
141 | } |
142 | ||
65b4b4e8 AM |
143 | module_init(ip6table_mangle_init); |
144 | module_exit(ip6table_mangle_fini); |