2 * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6
4 * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
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.
11 #include <linux/module.h>
12 #include <linux/netfilter_ipv6/ip6_tables.h>
13 #include <linux/slab.h>
16 MODULE_LICENSE("GPL");
17 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
18 MODULE_DESCRIPTION("ip6tables mangle table");
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))
26 static int __net_init ip6table_mangle_table_init(struct net *net);
28 static const struct xt_table packet_mangler = {
30 .valid_hooks = MANGLE_VALID_HOOKS,
33 .priority = NF_IP6_PRI_MANGLE,
34 .table_init = ip6table_mangle_table_init,
38 ip6t_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state)
41 struct in6_addr saddr, daddr;
43 u_int32_t flowlabel, mark;
46 /* save source/dest address, mark, hoplimit, flowlabel, priority, */
47 memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr));
48 memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr));
50 hop_limit = ipv6_hdr(skb)->hop_limit;
52 /* flowlabel and prio (includes version, which shouldn't change either */
53 flowlabel = *((u_int32_t *)ipv6_hdr(skb));
55 ret = ip6t_do_table(skb, state, state->net->ipv6.ip6table_mangle);
57 if (ret != NF_DROP && ret != NF_STOLEN &&
58 (!ipv6_addr_equal(&ipv6_hdr(skb)->saddr, &saddr) ||
59 !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) ||
61 ipv6_hdr(skb)->hop_limit != hop_limit ||
62 flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) {
63 err = ip6_route_me_harder(state->net, state->sk, skb);
65 ret = NF_DROP_ERR(err);
71 /* The work comes in here from netfilter.c. */
73 ip6table_mangle_hook(void *priv, struct sk_buff *skb,
74 const struct nf_hook_state *state)
76 if (state->hook == NF_INET_LOCAL_OUT)
77 return ip6t_mangle_out(skb, state);
78 return ip6t_do_table(skb, state, state->net->ipv6.ip6table_mangle);
81 static struct nf_hook_ops *mangle_ops __read_mostly;
82 static int __net_init ip6table_mangle_table_init(struct net *net)
84 struct ip6t_replace *repl;
87 if (net->ipv6.ip6table_mangle)
90 repl = ip6t_alloc_initial_table(&packet_mangler);
93 ret = ip6t_register_table(net, &packet_mangler, repl, mangle_ops,
94 &net->ipv6.ip6table_mangle);
99 static void __net_exit ip6table_mangle_net_exit(struct net *net)
101 if (!net->ipv6.ip6table_mangle)
104 ip6t_unregister_table(net, net->ipv6.ip6table_mangle, mangle_ops);
105 net->ipv6.ip6table_mangle = NULL;
108 static struct pernet_operations ip6table_mangle_net_ops = {
109 .exit = ip6table_mangle_net_exit,
112 static int __init ip6table_mangle_init(void)
116 mangle_ops = xt_hook_ops_alloc(&packet_mangler, ip6table_mangle_hook);
117 if (IS_ERR(mangle_ops))
118 return PTR_ERR(mangle_ops);
120 ret = register_pernet_subsys(&ip6table_mangle_net_ops);
126 ret = ip6table_mangle_table_init(&init_net);
128 unregister_pernet_subsys(&ip6table_mangle_net_ops);
134 static void __exit ip6table_mangle_fini(void)
136 unregister_pernet_subsys(&ip6table_mangle_net_ops);
140 module_init(ip6table_mangle_init);
141 module_exit(ip6table_mangle_fini);