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_IP6_PRE_ROUTING) | \
19 (1 << NF_IP6_LOCAL_IN) | \
20 (1 << NF_IP6_FORWARD) | \
21 (1 << NF_IP6_LOCAL_OUT) | \
22 (1 << NF_IP6_POST_ROUTING))
26 struct ip6t_replace repl;
27 struct ip6t_standard entries[5];
28 struct ip6t_error term;
29 } initial_table __initdata = {
32 .valid_hooks = MANGLE_VALID_HOOKS,
34 .size = sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
36 [NF_IP6_PRE_ROUTING] = 0,
37 [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
38 [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
39 [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
40 [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4,
43 [NF_IP6_PRE_ROUTING] = 0,
44 [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
45 [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
46 [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
47 [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4,
51 IP6T_STANDARD_INIT(NF_ACCEPT), /* PRE_ROUTING */
52 IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
53 IP6T_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
54 IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
55 IP6T_STANDARD_INIT(NF_ACCEPT), /* POST_ROUTING */
57 .term = IP6T_ERROR_INIT, /* ERROR */
60 static struct xt_table packet_mangler = {
62 .valid_hooks = MANGLE_VALID_HOOKS,
63 .lock = RW_LOCK_UNLOCKED,
68 /* The work comes in here from netfilter.c. */
70 ip6t_route_hook(unsigned int hook,
71 struct sk_buff **pskb,
72 const struct net_device *in,
73 const struct net_device *out,
74 int (*okfn)(struct sk_buff *))
76 return ip6t_do_table(pskb, hook, in, out, &packet_mangler);
80 ip6t_local_hook(unsigned int hook,
81 struct sk_buff **pskb,
82 const struct net_device *in,
83 const struct net_device *out,
84 int (*okfn)(struct sk_buff *))
88 struct in6_addr saddr, daddr;
90 u_int32_t flowlabel, mark;
93 /* root is playing with raw sockets. */
94 if ((*pskb)->len < sizeof(struct iphdr)
95 || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
97 printk("ip6t_hook: happy cracking.\n");
102 /* save source/dest address, mark, hoplimit, flowlabel, priority, */
103 memcpy(&saddr, &ipv6_hdr(*pskb)->saddr, sizeof(saddr));
104 memcpy(&daddr, &ipv6_hdr(*pskb)->daddr, sizeof(daddr));
105 mark = (*pskb)->mark;
106 hop_limit = ipv6_hdr(*pskb)->hop_limit;
108 /* flowlabel and prio (includes version, which shouldn't change either */
109 flowlabel = *((u_int32_t *)ipv6_hdr(*pskb));
111 ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler);
113 if (ret != NF_DROP && ret != NF_STOLEN
114 && (memcmp(&ipv6_hdr(*pskb)->saddr, &saddr, sizeof(saddr))
115 || memcmp(&ipv6_hdr(*pskb)->daddr, &daddr, sizeof(daddr))
116 || (*pskb)->mark != mark
117 || ipv6_hdr(*pskb)->hop_limit != hop_limit))
118 return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP;
123 static struct nf_hook_ops ip6t_ops[] = {
125 .hook = ip6t_route_hook,
126 .owner = THIS_MODULE,
128 .hooknum = NF_IP6_PRE_ROUTING,
129 .priority = NF_IP6_PRI_MANGLE,
132 .hook = ip6t_local_hook,
133 .owner = THIS_MODULE,
135 .hooknum = NF_IP6_LOCAL_IN,
136 .priority = NF_IP6_PRI_MANGLE,
139 .hook = ip6t_route_hook,
140 .owner = THIS_MODULE,
142 .hooknum = NF_IP6_FORWARD,
143 .priority = NF_IP6_PRI_MANGLE,
146 .hook = ip6t_local_hook,
147 .owner = THIS_MODULE,
149 .hooknum = NF_IP6_LOCAL_OUT,
150 .priority = NF_IP6_PRI_MANGLE,
153 .hook = ip6t_route_hook,
154 .owner = THIS_MODULE,
156 .hooknum = NF_IP6_POST_ROUTING,
157 .priority = NF_IP6_PRI_MANGLE,
161 static int __init ip6table_mangle_init(void)
166 ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
171 ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
178 ip6t_unregister_table(&packet_mangler);
182 static void __exit ip6table_mangle_fini(void)
184 nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
185 ip6t_unregister_table(&packet_mangler);
188 module_init(ip6table_mangle_init);
189 module_exit(ip6table_mangle_fini);