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 * Extended to all five netfilter hooks by Brad Chapman & Harald Welte
13 #include <linux/module.h>
14 #include <linux/netfilter_ipv6/ip6_tables.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_IP6_PRE_ROUTING) | \
21 (1 << NF_IP6_LOCAL_IN) | \
22 (1 << NF_IP6_FORWARD) | \
23 (1 << NF_IP6_LOCAL_OUT) | \
24 (1 << NF_IP6_POST_ROUTING))
27 #define DEBUGP(x, args...) printk(KERN_DEBUG x, ## args)
29 #define DEBUGP(x, args...)
34 struct ip6t_replace repl;
35 struct ip6t_standard entries[5];
36 struct ip6t_error term;
37 } initial_table __initdata
38 = { { "mangle", MANGLE_VALID_HOOKS, 6,
39 sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
40 { [NF_IP6_PRE_ROUTING] = 0,
41 [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
42 [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
43 [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
44 [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
45 { [NF_IP6_PRE_ROUTING] = 0,
46 [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
47 [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
48 [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
49 [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
53 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
55 sizeof(struct ip6t_entry),
56 sizeof(struct ip6t_standard),
58 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
61 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
63 sizeof(struct ip6t_entry),
64 sizeof(struct ip6t_standard),
66 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
69 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
71 sizeof(struct ip6t_entry),
72 sizeof(struct ip6t_standard),
74 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
77 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
79 sizeof(struct ip6t_entry),
80 sizeof(struct ip6t_standard),
82 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
85 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
87 sizeof(struct ip6t_entry),
88 sizeof(struct ip6t_standard),
90 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
94 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
96 sizeof(struct ip6t_entry),
97 sizeof(struct ip6t_error),
99 { { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
106 static struct xt_table packet_mangler = {
108 .valid_hooks = MANGLE_VALID_HOOKS,
109 .lock = RW_LOCK_UNLOCKED,
114 /* The work comes in here from netfilter.c. */
116 ip6t_route_hook(unsigned int hook,
117 struct sk_buff **pskb,
118 const struct net_device *in,
119 const struct net_device *out,
120 int (*okfn)(struct sk_buff *))
122 return ip6t_do_table(pskb, hook, in, out, &packet_mangler);
126 ip6t_local_hook(unsigned int hook,
127 struct sk_buff **pskb,
128 const struct net_device *in,
129 const struct net_device *out,
130 int (*okfn)(struct sk_buff *))
134 struct in6_addr saddr, daddr;
136 u_int32_t flowlabel, mark;
139 /* root is playing with raw sockets. */
140 if ((*pskb)->len < sizeof(struct iphdr)
141 || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
143 printk("ip6t_hook: happy cracking.\n");
148 /* save source/dest address, mark, hoplimit, flowlabel, priority, */
149 memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr));
150 memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr));
151 mark = (*pskb)->mark;
152 hop_limit = (*pskb)->nh.ipv6h->hop_limit;
154 /* flowlabel and prio (includes version, which shouldn't change either */
155 flowlabel = *((u_int32_t *) (*pskb)->nh.ipv6h);
157 ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler);
159 if (ret != NF_DROP && ret != NF_STOLEN
160 && (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr))
161 || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr))
162 || (*pskb)->mark != mark
163 || (*pskb)->nh.ipv6h->hop_limit != hop_limit))
164 return ip6_route_me_harder(*pskb) == 0 ? ret : NF_DROP;
169 static struct nf_hook_ops ip6t_ops[] = {
171 .hook = ip6t_route_hook,
172 .owner = THIS_MODULE,
174 .hooknum = NF_IP6_PRE_ROUTING,
175 .priority = NF_IP6_PRI_MANGLE,
178 .hook = ip6t_local_hook,
179 .owner = THIS_MODULE,
181 .hooknum = NF_IP6_LOCAL_IN,
182 .priority = NF_IP6_PRI_MANGLE,
185 .hook = ip6t_route_hook,
186 .owner = THIS_MODULE,
188 .hooknum = NF_IP6_FORWARD,
189 .priority = NF_IP6_PRI_MANGLE,
192 .hook = ip6t_local_hook,
193 .owner = THIS_MODULE,
195 .hooknum = NF_IP6_LOCAL_OUT,
196 .priority = NF_IP6_PRI_MANGLE,
199 .hook = ip6t_route_hook,
200 .owner = THIS_MODULE,
202 .hooknum = NF_IP6_POST_ROUTING,
203 .priority = NF_IP6_PRI_MANGLE,
207 static int __init ip6table_mangle_init(void)
212 ret = ip6t_register_table(&packet_mangler, &initial_table.repl);
217 ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
224 ip6t_unregister_table(&packet_mangler);
228 static void __exit ip6table_mangle_fini(void)
230 nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
231 ip6t_unregister_table(&packet_mangler);
234 module_init(ip6table_mangle_init);
235 module_exit(ip6table_mangle_fini);