| /* |
| * 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> |
| #include <linux/slab.h> |
| #include <net/ipv6.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 int __net_init ip6table_mangle_table_init(struct net *net); |
| |
| static const struct xt_table packet_mangler = { |
| .name = "mangle", |
| .valid_hooks = MANGLE_VALID_HOOKS, |
| .me = THIS_MODULE, |
| .af = NFPROTO_IPV6, |
| .priority = NF_IP6_PRI_MANGLE, |
| .table_init = ip6table_mangle_table_init, |
| }; |
| |
| static unsigned int |
| ip6t_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state) |
| { |
| unsigned int ret; |
| struct in6_addr saddr, daddr; |
| u_int8_t hop_limit; |
| u_int32_t flowlabel, mark; |
| int err; |
| |
| /* 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, state, state->net->ipv6.ip6table_mangle); |
| |
| if (ret != NF_DROP && ret != NF_STOLEN && |
| (!ipv6_addr_equal(&ipv6_hdr(skb)->saddr, &saddr) || |
| !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) || |
| skb->mark != mark || |
| ipv6_hdr(skb)->hop_limit != hop_limit || |
| flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) { |
| err = ip6_route_me_harder(state->net, skb); |
| if (err < 0) |
| ret = NF_DROP_ERR(err); |
| } |
| |
| return ret; |
| } |
| |
| /* The work comes in here from netfilter.c. */ |
| static unsigned int |
| ip6table_mangle_hook(void *priv, struct sk_buff *skb, |
| const struct nf_hook_state *state) |
| { |
| if (state->hook == NF_INET_LOCAL_OUT) |
| return ip6t_mangle_out(skb, state); |
| return ip6t_do_table(skb, state, state->net->ipv6.ip6table_mangle); |
| } |
| |
| static struct nf_hook_ops *mangle_ops __read_mostly; |
| static int __net_init ip6table_mangle_table_init(struct net *net) |
| { |
| struct ip6t_replace *repl; |
| int ret; |
| |
| if (net->ipv6.ip6table_mangle) |
| return 0; |
| |
| repl = ip6t_alloc_initial_table(&packet_mangler); |
| if (repl == NULL) |
| return -ENOMEM; |
| ret = ip6t_register_table(net, &packet_mangler, repl, mangle_ops, |
| &net->ipv6.ip6table_mangle); |
| kfree(repl); |
| return ret; |
| } |
| |
| static void __net_exit ip6table_mangle_net_exit(struct net *net) |
| { |
| if (!net->ipv6.ip6table_mangle) |
| return; |
| |
| ip6t_unregister_table(net, net->ipv6.ip6table_mangle, mangle_ops); |
| net->ipv6.ip6table_mangle = NULL; |
| } |
| |
| static struct pernet_operations ip6table_mangle_net_ops = { |
| .exit = ip6table_mangle_net_exit, |
| }; |
| |
| static int __init ip6table_mangle_init(void) |
| { |
| int ret; |
| |
| mangle_ops = xt_hook_ops_alloc(&packet_mangler, ip6table_mangle_hook); |
| if (IS_ERR(mangle_ops)) |
| return PTR_ERR(mangle_ops); |
| |
| ret = register_pernet_subsys(&ip6table_mangle_net_ops); |
| if (ret < 0) { |
| kfree(mangle_ops); |
| return ret; |
| } |
| |
| ret = ip6table_mangle_table_init(&init_net); |
| if (ret) { |
| unregister_pernet_subsys(&ip6table_mangle_net_ops); |
| kfree(mangle_ops); |
| } |
| return ret; |
| } |
| |
| static void __exit ip6table_mangle_fini(void) |
| { |
| unregister_pernet_subsys(&ip6table_mangle_net_ops); |
| kfree(mangle_ops); |
| } |
| |
| module_init(ip6table_mangle_init); |
| module_exit(ip6table_mangle_fini); |