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>
14 MODULE_LICENSE("GPL");
15 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
16 MODULE_DESCRIPTION("ip6tables mangle table");
18 #define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \
19 (1 << NF_INET_LOCAL_IN) | \
20 (1 << NF_INET_FORWARD) | \
21 (1 << NF_INET_LOCAL_OUT) | \
22 (1 << NF_INET_POST_ROUTING))
24 static const struct xt_table packet_mangler
= {
26 .valid_hooks
= MANGLE_VALID_HOOKS
,
29 .priority
= NF_IP6_PRI_MANGLE
,
33 ip6t_local_out_hook(unsigned int hook
,
35 const struct net_device
*out
,
36 int (*okfn
)(struct sk_buff
*))
40 struct in6_addr saddr
, daddr
;
42 u_int32_t flowlabel
, mark
;
45 /* root is playing with raw sockets. */
46 if (skb
->len
< sizeof(struct iphdr
) ||
47 ip_hdrlen(skb
) < sizeof(struct iphdr
)) {
49 printk("ip6t_hook: happy cracking.\n");
54 /* save source/dest address, mark, hoplimit, flowlabel, priority, */
55 memcpy(&saddr
, &ipv6_hdr(skb
)->saddr
, sizeof(saddr
));
56 memcpy(&daddr
, &ipv6_hdr(skb
)->daddr
, sizeof(daddr
));
58 hop_limit
= ipv6_hdr(skb
)->hop_limit
;
60 /* flowlabel and prio (includes version, which shouldn't change either */
61 flowlabel
= *((u_int32_t
*)ipv6_hdr(skb
));
63 ret
= ip6t_do_table(skb
, hook
, NULL
, out
,
64 dev_net(out
)->ipv6
.ip6table_mangle
);
66 if (ret
!= NF_DROP
&& ret
!= NF_STOLEN
&&
67 (memcmp(&ipv6_hdr(skb
)->saddr
, &saddr
, sizeof(saddr
)) ||
68 memcmp(&ipv6_hdr(skb
)->daddr
, &daddr
, sizeof(daddr
)) ||
70 ipv6_hdr(skb
)->hop_limit
!= hop_limit
))
71 return ip6_route_me_harder(skb
) == 0 ? ret
: NF_DROP
;
76 /* The work comes in here from netfilter.c. */
78 ip6table_mangle_hook(unsigned int hook
, struct sk_buff
*skb
,
79 const struct net_device
*in
, const struct net_device
*out
,
80 int (*okfn
)(struct sk_buff
*))
82 if (hook
== NF_INET_LOCAL_OUT
)
83 return ip6t_local_out_hook(hook
, skb
, out
, okfn
);
84 if (hook
== NF_INET_POST_ROUTING
)
85 return ip6t_do_table(skb
, hook
, in
, out
,
86 dev_net(out
)->ipv6
.ip6table_mangle
);
88 return ip6t_do_table(skb
, hook
, in
, out
,
89 dev_net(in
)->ipv6
.ip6table_mangle
);
92 static struct nf_hook_ops
*mangle_ops __read_mostly
;
93 static int __net_init
ip6table_mangle_net_init(struct net
*net
)
95 struct ip6t_replace
*repl
;
97 repl
= ip6t_alloc_initial_table(&packet_mangler
);
100 net
->ipv6
.ip6table_mangle
=
101 ip6t_register_table(net
, &packet_mangler
, repl
);
103 if (IS_ERR(net
->ipv6
.ip6table_mangle
))
104 return PTR_ERR(net
->ipv6
.ip6table_mangle
);
108 static void __net_exit
ip6table_mangle_net_exit(struct net
*net
)
110 ip6t_unregister_table(net
, net
->ipv6
.ip6table_mangle
);
113 static struct pernet_operations ip6table_mangle_net_ops
= {
114 .init
= ip6table_mangle_net_init
,
115 .exit
= ip6table_mangle_net_exit
,
118 static int __init
ip6table_mangle_init(void)
122 ret
= register_pernet_subsys(&ip6table_mangle_net_ops
);
127 mangle_ops
= xt_hook_link(&packet_mangler
, ip6table_mangle_hook
);
128 if (IS_ERR(mangle_ops
)) {
129 ret
= PTR_ERR(mangle_ops
);
136 unregister_pernet_subsys(&ip6table_mangle_net_ops
);
140 static void __exit
ip6table_mangle_fini(void)
142 xt_hook_unlink(&packet_mangler
, mangle_ops
);
143 unregister_pernet_subsys(&ip6table_mangle_net_ops
);
146 module_init(ip6table_mangle_init
);
147 module_exit(ip6table_mangle_fini
);