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> |
d9e85655 | 14 | #include <net/ipv6.h> |
1da177e4 LT |
15 | |
16 | MODULE_LICENSE("GPL"); | |
17 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
18 | MODULE_DESCRIPTION("ip6tables mangle table"); | |
19 | ||
6e23ae2a PM |
20 | #define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \ |
21 | (1 << NF_INET_LOCAL_IN) | \ | |
22 | (1 << NF_INET_FORWARD) | \ | |
23 | (1 << NF_INET_LOCAL_OUT) | \ | |
24 | (1 << NF_INET_POST_ROUTING)) | |
1da177e4 | 25 | |
35aad0ff | 26 | static const struct xt_table packet_mangler = { |
1da177e4 LT |
27 | .name = "mangle", |
28 | .valid_hooks = MANGLE_VALID_HOOKS, | |
1da177e4 | 29 | .me = THIS_MODULE, |
f88e6a8a | 30 | .af = NFPROTO_IPV6, |
2b95efe7 | 31 | .priority = NF_IP6_PRI_MANGLE, |
1da177e4 LT |
32 | }; |
33 | ||
7dd1b8da | 34 | static unsigned int |
fa96a0e2 | 35 | ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out) |
1da177e4 | 36 | { |
1da177e4 LT |
37 | unsigned int ret; |
38 | struct in6_addr saddr, daddr; | |
39 | u_int8_t hop_limit; | |
82e91ffe | 40 | u_int32_t flowlabel, mark; |
58e35d14 | 41 | int err; |
1da177e4 LT |
42 | #if 0 |
43 | /* root is playing with raw sockets. */ | |
3666ed1c JP |
44 | if (skb->len < sizeof(struct iphdr) || |
45 | ip_hdrlen(skb) < sizeof(struct iphdr)) { | |
e87cc472 | 46 | net_warn_ratelimited("ip6t_hook: happy cracking\n"); |
1da177e4 LT |
47 | return NF_ACCEPT; |
48 | } | |
49 | #endif | |
50 | ||
82e91ffe | 51 | /* save source/dest address, mark, hoplimit, flowlabel, priority, */ |
3db05fea HX |
52 | memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr)); |
53 | memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr)); | |
54 | mark = skb->mark; | |
55 | hop_limit = ipv6_hdr(skb)->hop_limit; | |
1da177e4 LT |
56 | |
57 | /* flowlabel and prio (includes version, which shouldn't change either */ | |
3db05fea | 58 | flowlabel = *((u_int32_t *)ipv6_hdr(skb)); |
1da177e4 | 59 | |
fa96a0e2 | 60 | ret = ip6t_do_table(skb, NF_INET_LOCAL_OUT, NULL, out, |
7dd1b8da | 61 | dev_net(out)->ipv6.ip6table_mangle); |
1da177e4 | 62 | |
3666ed1c | 63 | if (ret != NF_DROP && ret != NF_STOLEN && |
d9e85655 YH |
64 | (!ipv6_addr_equal(&ipv6_hdr(skb)->saddr, &saddr) || |
65 | !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) || | |
3666ed1c | 66 | skb->mark != mark || |
b169f6db | 67 | ipv6_hdr(skb)->hop_limit != hop_limit || |
58e35d14 PM |
68 | flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) { |
69 | err = ip6_route_me_harder(skb); | |
70 | if (err < 0) | |
71 | ret = NF_DROP_ERR(err); | |
72 | } | |
1da177e4 LT |
73 | |
74 | return ret; | |
75 | } | |
76 | ||
737535c5 JE |
77 | /* The work comes in here from netfilter.c. */ |
78 | static unsigned int | |
795aa6ef | 79 | ip6table_mangle_hook(const struct nf_hook_ops *ops, struct sk_buff *skb, |
238e54c9 | 80 | const struct nf_hook_state *state) |
737535c5 | 81 | { |
795aa6ef | 82 | if (ops->hooknum == NF_INET_LOCAL_OUT) |
238e54c9 | 83 | return ip6t_mangle_out(skb, state->out); |
795aa6ef | 84 | if (ops->hooknum == NF_INET_POST_ROUTING) |
238e54c9 DM |
85 | return ip6t_do_table(skb, ops->hooknum, state->in, state->out, |
86 | dev_net(state->out)->ipv6.ip6table_mangle); | |
737535c5 | 87 | /* INPUT/FORWARD */ |
238e54c9 DM |
88 | return ip6t_do_table(skb, ops->hooknum, state->in, state->out, |
89 | dev_net(state->in)->ipv6.ip6table_mangle); | |
737535c5 JE |
90 | } |
91 | ||
2b95efe7 | 92 | static struct nf_hook_ops *mangle_ops __read_mostly; |
8280aa61 AD |
93 | static int __net_init ip6table_mangle_net_init(struct net *net) |
94 | { | |
e3eaa991 JE |
95 | struct ip6t_replace *repl; |
96 | ||
97 | repl = ip6t_alloc_initial_table(&packet_mangler); | |
98 | if (repl == NULL) | |
99 | return -ENOMEM; | |
8280aa61 | 100 | net->ipv6.ip6table_mangle = |
e3eaa991 JE |
101 | ip6t_register_table(net, &packet_mangler, repl); |
102 | kfree(repl); | |
8c6ffba0 | 103 | return PTR_ERR_OR_ZERO(net->ipv6.ip6table_mangle); |
8280aa61 AD |
104 | } |
105 | ||
106 | static void __net_exit ip6table_mangle_net_exit(struct net *net) | |
107 | { | |
f54e9367 | 108 | ip6t_unregister_table(net, net->ipv6.ip6table_mangle); |
8280aa61 AD |
109 | } |
110 | ||
111 | static struct pernet_operations ip6table_mangle_net_ops = { | |
112 | .init = ip6table_mangle_net_init, | |
113 | .exit = ip6table_mangle_net_exit, | |
114 | }; | |
115 | ||
65b4b4e8 | 116 | static int __init ip6table_mangle_init(void) |
1da177e4 LT |
117 | { |
118 | int ret; | |
119 | ||
8280aa61 AD |
120 | ret = register_pernet_subsys(&ip6table_mangle_net_ops); |
121 | if (ret < 0) | |
122 | return ret; | |
1da177e4 LT |
123 | |
124 | /* Register hooks */ | |
2b95efe7 JE |
125 | mangle_ops = xt_hook_link(&packet_mangler, ip6table_mangle_hook); |
126 | if (IS_ERR(mangle_ops)) { | |
127 | ret = PTR_ERR(mangle_ops); | |
1da177e4 | 128 | goto cleanup_table; |
2b95efe7 | 129 | } |
1da177e4 | 130 | |
1da177e4 LT |
131 | return ret; |
132 | ||
1da177e4 | 133 | cleanup_table: |
8280aa61 | 134 | unregister_pernet_subsys(&ip6table_mangle_net_ops); |
1da177e4 LT |
135 | return ret; |
136 | } | |
137 | ||
65b4b4e8 | 138 | static void __exit ip6table_mangle_fini(void) |
1da177e4 | 139 | { |
2b95efe7 | 140 | xt_hook_unlink(&packet_mangler, mangle_ops); |
8280aa61 | 141 | unregister_pernet_subsys(&ip6table_mangle_net_ops); |
1da177e4 LT |
142 | } |
143 | ||
65b4b4e8 AM |
144 | module_init(ip6table_mangle_init); |
145 | module_exit(ip6table_mangle_fini); |