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/*
* IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6
*
* Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
* Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("ip6tables mangle table");
#define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \
(1 << NF_INET_LOCAL_IN) | \
(1 << NF_INET_FORWARD) | \
(1 << NF_INET_LOCAL_OUT) | \
(1 << NF_INET_POST_ROUTING))
static struct
{
struct ip6t_replace repl;
struct ip6t_standard entries[5];
struct ip6t_error term;
} initial_table __net_initdata = {
.repl = {
.name = "mangle",
.valid_hooks = MANGLE_VALID_HOOKS,
.num_entries = 6,
.size = sizeof(struct ip6t_standard) * 5 + sizeof(struct ip6t_error),
.hook_entry = {
[NF_INET_PRE_ROUTING] = 0,
[NF_INET_LOCAL_IN] = sizeof(struct ip6t_standard),
[NF_INET_FORWARD] = sizeof(struct ip6t_standard) * 2,
[NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
[NF_INET_POST_ROUTING] = sizeof(struct ip6t_standard) * 4,
},
.underflow = {
[NF_INET_PRE_ROUTING] = 0,
[NF_INET_LOCAL_IN] = sizeof(struct ip6t_standard),
[NF_INET_FORWARD] = sizeof(struct ip6t_standard) * 2,
[NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 3,
[NF_INET_POST_ROUTING] = sizeof(struct ip6t_standard) * 4,
},
},
.entries = {
IP6T_STANDARD_INIT(NF_ACCEPT), /* PRE_ROUTING */
IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
IP6T_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
IP6T_STANDARD_INIT(NF_ACCEPT), /* POST_ROUTING */
},
.term = IP6T_ERROR_INIT, /* ERROR */
};
static struct xt_table packet_mangler = {
.name = "mangle",
.valid_hooks = MANGLE_VALID_HOOKS,
.lock = __RW_LOCK_UNLOCKED(packet_mangler.lock),
.me = THIS_MODULE,
.af = AF_INET6,
};
/* The work comes in here from netfilter.c. */
static unsigned int
ip6t_route_hook(unsigned int hook,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
return ip6t_do_table(skb, hook, in, out, init_net.ipv6.ip6table_mangle);
}
static unsigned int
ip6t_local_hook(unsigned int hook,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
unsigned int ret;
struct in6_addr saddr, daddr;
u_int8_t hop_limit;
u_int32_t flowlabel, mark;
#if 0
/* root is playing with raw sockets. */
if (skb->len < sizeof(struct iphdr)
|| ip_hdrlen(skb) < sizeof(struct iphdr)) {
if (net_ratelimit())
printk("ip6t_hook: happy cracking.\n");
return NF_ACCEPT;
}
#endif
/* save source/dest address, mark, hoplimit, flowlabel, priority, */
memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr));
memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr));
mark = skb->mark;
hop_limit = ipv6_hdr(skb)->hop_limit;
/* flowlabel and prio (includes version, which shouldn't change either */
flowlabel = *((u_int32_t *)ipv6_hdr(skb));
ret = ip6t_do_table(skb, hook, in, out, init_net.ipv6.ip6table_mangle);
if (ret != NF_DROP && ret != NF_STOLEN
&& (memcmp(&ipv6_hdr(skb)->saddr, &saddr, sizeof(saddr))
|| memcmp(&ipv6_hdr(skb)->daddr, &daddr, sizeof(daddr))
|| skb->mark != mark
|| ipv6_hdr(skb)->hop_limit != hop_limit))
return ip6_route_me_harder(skb) == 0 ? ret : NF_DROP;
return ret;
}
static struct nf_hook_ops ip6t_ops[] __read_mostly = {
{
.hook = ip6t_route_hook,
.owner = THIS_MODULE,
.pf = PF_INET6,
.hooknum = NF_INET_PRE_ROUTING,
.priority = NF_IP6_PRI_MANGLE,
},
{
.hook = ip6t_route_hook,
.owner = THIS_MODULE,
.pf = PF_INET6,
.hooknum = NF_INET_LOCAL_IN,
.priority = NF_IP6_PRI_MANGLE,
},
{
.hook = ip6t_route_hook,
.owner = THIS_MODULE,
.pf = PF_INET6,
.hooknum = NF_INET_FORWARD,
.priority = NF_IP6_PRI_MANGLE,
},
{
.hook = ip6t_local_hook,
.owner = THIS_MODULE,
.pf = PF_INET6,
.hooknum = NF_INET_LOCAL_OUT,
.priority = NF_IP6_PRI_MANGLE,
},
{
.hook = ip6t_route_hook,
.owner = THIS_MODULE,
.pf = PF_INET6,
.hooknum = NF_INET_POST_ROUTING,
.priority = NF_IP6_PRI_MANGLE,
},
};
static int __net_init ip6table_mangle_net_init(struct net *net)
{
/* Register table */
net->ipv6.ip6table_mangle =
ip6t_register_table(net, &packet_mangler, &initial_table.repl);
if (IS_ERR(net->ipv6.ip6table_mangle))
return PTR_ERR(net->ipv6.ip6table_mangle);
return 0;
}
static void __net_exit ip6table_mangle_net_exit(struct net *net)
{
ip6t_unregister_table(net->ipv6.ip6table_mangle);
}
static struct pernet_operations ip6table_mangle_net_ops = {
.init = ip6table_mangle_net_init,
.exit = ip6table_mangle_net_exit,
};
static int __init ip6table_mangle_init(void)
{
int ret;
ret = register_pernet_subsys(&ip6table_mangle_net_ops);
if (ret < 0)
return ret;
/* Register hooks */
ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
if (ret < 0)
goto cleanup_table;
return ret;
cleanup_table:
unregister_pernet_subsys(&ip6table_mangle_net_ops);
return ret;
}
static void __exit ip6table_mangle_fini(void)
{
nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
unregister_pernet_subsys(&ip6table_mangle_net_ops);
}
module_init(ip6table_mangle_init);
module_exit(ip6table_mangle_fini);
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