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...)
35 struct ip6t_entry entry;
36 struct ip6t_standard_target target;
39 struct ip6t_error_target
41 struct ip6t_entry_target target;
42 char errorname[IP6T_FUNCTION_MAXNAMELEN];
47 struct ip6t_entry entry;
48 struct ip6t_error_target target;
53 struct ip6t_replace repl;
54 struct ip6t_standard entries[5];
55 struct ip6t_error term;
56 } initial_table __initdata
57 = { { "mangle", MANGLE_VALID_HOOKS, 6,
58 sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
59 { [NF_IP6_PRE_ROUTING] = 0,
60 [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
61 [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
62 [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
63 [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
64 { [NF_IP6_PRE_ROUTING] = 0,
65 [NF_IP6_LOCAL_IN] = sizeof(struct ip6t_standard),
66 [NF_IP6_FORWARD] = sizeof(struct ip6t_standard) * 2,
67 [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
68 [NF_IP6_POST_ROUTING] = sizeof(struct ip6t_standard) * 4},
72 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
74 sizeof(struct ip6t_entry),
75 sizeof(struct ip6t_standard),
77 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
80 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
82 sizeof(struct ip6t_entry),
83 sizeof(struct ip6t_standard),
85 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
88 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
90 sizeof(struct ip6t_entry),
91 sizeof(struct ip6t_standard),
93 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
96 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
98 sizeof(struct ip6t_entry),
99 sizeof(struct ip6t_standard),
101 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
104 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
106 sizeof(struct ip6t_entry),
107 sizeof(struct ip6t_standard),
109 { { { { IP6T_ALIGN(sizeof(struct ip6t_standard_target)), "" } }, { } },
113 { { { { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, { { { 0 } } }, "", "", { 0 }, { 0 }, 0, 0, 0 },
115 sizeof(struct ip6t_entry),
116 sizeof(struct ip6t_error),
118 { { { { IP6T_ALIGN(sizeof(struct ip6t_error_target)), IP6T_ERROR_TARGET } },
125 static struct ip6t_table packet_mangler = {
127 .table = &initial_table.repl,
128 .valid_hooks = MANGLE_VALID_HOOKS,
129 .lock = RW_LOCK_UNLOCKED,
133 /* The work comes in here from netfilter.c. */
135 ip6t_route_hook(unsigned int hook,
136 struct sk_buff **pskb,
137 const struct net_device *in,
138 const struct net_device *out,
139 int (*okfn)(struct sk_buff *))
141 return ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL);
145 ip6t_local_hook(unsigned int hook,
146 struct sk_buff **pskb,
147 const struct net_device *in,
148 const struct net_device *out,
149 int (*okfn)(struct sk_buff *))
152 unsigned long nfmark;
154 struct in6_addr saddr, daddr;
159 /* root is playing with raw sockets. */
160 if ((*pskb)->len < sizeof(struct iphdr)
161 || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
163 printk("ip6t_hook: happy cracking.\n");
168 /* FIXME: Push down to extensions --RR */
169 if (skb_is_nonlinear(*pskb) && skb_linearize(*pskb, GFP_ATOMIC) != 0)
172 /* save source/dest address, nfmark, hoplimit, flowlabel, priority, */
173 memcpy(&saddr, &(*pskb)->nh.ipv6h->saddr, sizeof(saddr));
174 memcpy(&daddr, &(*pskb)->nh.ipv6h->daddr, sizeof(daddr));
175 nfmark = (*pskb)->nfmark;
176 hop_limit = (*pskb)->nh.ipv6h->hop_limit;
178 /* flowlabel and prio (includes version, which shouldn't change either */
179 flowlabel = *((u_int32_t *) (*pskb)->nh.ipv6h);
181 ret = ip6t_do_table(pskb, hook, in, out, &packet_mangler, NULL);
183 if (ret != NF_DROP && ret != NF_STOLEN
184 && (memcmp(&(*pskb)->nh.ipv6h->saddr, &saddr, sizeof(saddr))
185 || memcmp(&(*pskb)->nh.ipv6h->daddr, &daddr, sizeof(daddr))
186 || (*pskb)->nfmark != nfmark
187 || (*pskb)->nh.ipv6h->hop_limit != hop_limit)) {
189 /* something which could affect routing has changed */
191 DEBUGP("ip6table_mangle: we'd need to re-route a packet\n");
197 static struct nf_hook_ops ip6t_ops[] = {
199 .hook = ip6t_route_hook,
200 .owner = THIS_MODULE,
202 .hooknum = NF_IP6_PRE_ROUTING,
203 .priority = NF_IP6_PRI_MANGLE,
206 .hook = ip6t_local_hook,
207 .owner = THIS_MODULE,
209 .hooknum = NF_IP6_LOCAL_IN,
210 .priority = NF_IP6_PRI_MANGLE,
213 .hook = ip6t_route_hook,
214 .owner = THIS_MODULE,
216 .hooknum = NF_IP6_FORWARD,
217 .priority = NF_IP6_PRI_MANGLE,
220 .hook = ip6t_local_hook,
221 .owner = THIS_MODULE,
223 .hooknum = NF_IP6_LOCAL_OUT,
224 .priority = NF_IP6_PRI_MANGLE,
227 .hook = ip6t_route_hook,
228 .owner = THIS_MODULE,
230 .hooknum = NF_IP6_POST_ROUTING,
231 .priority = NF_IP6_PRI_MANGLE,
235 static int __init init(void)
240 ret = ip6t_register_table(&packet_mangler);
245 ret = nf_register_hook(&ip6t_ops[0]);
249 ret = nf_register_hook(&ip6t_ops[1]);
253 ret = nf_register_hook(&ip6t_ops[2]);
257 ret = nf_register_hook(&ip6t_ops[3]);
261 ret = nf_register_hook(&ip6t_ops[4]);
268 nf_unregister_hook(&ip6t_ops[3]);
270 nf_unregister_hook(&ip6t_ops[2]);
272 nf_unregister_hook(&ip6t_ops[1]);
274 nf_unregister_hook(&ip6t_ops[0]);
276 ip6t_unregister_table(&packet_mangler);
281 static void __exit fini(void)
285 for (i = 0; i < sizeof(ip6t_ops)/sizeof(struct nf_hook_ops); i++)
286 nf_unregister_hook(&ip6t_ops[i]);
288 ip6t_unregister_table(&packet_mangler);