1/* 2 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> 3 * Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * Development of this code funded by Astaro AG (http://www.astaro.com/) 10 */ 11 12#include <linux/module.h> 13#include <linux/init.h> 14#include <linux/list.h> 15#include <linux/skbuff.h> 16#include <linux/netlink.h> 17#include <linux/netfilter.h> 18#include <linux/netfilter_ipv6.h> 19#include <linux/netfilter/nfnetlink.h> 20#include <linux/netfilter/nf_tables.h> 21#include <net/netfilter/nf_tables.h> 22#include <net/netfilter/nf_tables_ipv6.h> 23#include <net/route.h> 24 25static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops, 26 struct sk_buff *skb, 27 const struct net_device *in, 28 const struct net_device *out, 29 int (*okfn)(struct sk_buff *)) 30{ 31 unsigned int ret; 32 struct nft_pktinfo pkt; 33 struct in6_addr saddr, daddr; 34 u_int8_t hop_limit; 35 u32 mark, flowlabel; 36 37 /* malformed packet, drop it */ 38 if (nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out) < 0) 39 return NF_DROP; 40 41 /* save source/dest address, mark, hoplimit, flowlabel, priority */ 42 memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr)); 43 memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr)); 44 mark = skb->mark; 45 hop_limit = ipv6_hdr(skb)->hop_limit; 46 47 /* flowlabel and prio (includes version, which shouldn't change either */ 48 flowlabel = *((u32 *)ipv6_hdr(skb)); 49 50 ret = nft_do_chain(&pkt, ops); 51 if (ret != NF_DROP && ret != NF_QUEUE && 52 (memcmp(&ipv6_hdr(skb)->saddr, &saddr, sizeof(saddr)) || 53 memcmp(&ipv6_hdr(skb)->daddr, &daddr, sizeof(daddr)) || 54 skb->mark != mark || 55 ipv6_hdr(skb)->hop_limit != hop_limit || 56 flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) 57 return ip6_route_me_harder(skb) == 0 ? ret : NF_DROP; 58 59 return ret; 60} 61 62static const struct nf_chain_type nft_chain_route_ipv6 = { 63 .name = "route", 64 .type = NFT_CHAIN_T_ROUTE, 65 .family = NFPROTO_IPV6, 66 .owner = THIS_MODULE, 67 .hook_mask = (1 << NF_INET_LOCAL_OUT), 68 .hooks = { 69 [NF_INET_LOCAL_OUT] = nf_route_table_hook, 70 }, 71}; 72 73static int __init nft_chain_route_init(void) 74{ 75 return nft_register_chain_type(&nft_chain_route_ipv6); 76} 77 78static void __exit nft_chain_route_exit(void) 79{ 80 nft_unregister_chain_type(&nft_chain_route_ipv6); 81} 82 83module_init(nft_chain_route_init); 84module_exit(nft_chain_route_exit); 85 86MODULE_LICENSE("GPL"); 87MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 88MODULE_ALIAS_NFT_CHAIN(AF_INET6, "route"); 89