LXR linux/net/ipv6/netfilter/nft_chain_route

   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(void *priv,
  26                                        struct sk_buff *skb,
  27                                        const struct nf_hook_state *state)
  28{
  29        unsigned int ret;
  30        struct nft_pktinfo pkt;
  31        struct in6_addr saddr, daddr;
  32        u_int8_t hop_limit;
  33        u32 mark, flowlabel;
  34        int err;
  35
  36        nft_set_pktinfo(&pkt, skb, state);
  37        nft_set_pktinfo_ipv6(&pkt, skb);
  38
  39        /* save source/dest address, mark, hoplimit, flowlabel, priority */
  40        memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr));
  41        memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr));
  42        mark = skb->mark;
  43        hop_limit = ipv6_hdr(skb)->hop_limit;
  44
  45        /* flowlabel and prio (includes version, which shouldn't change either */
  46        flowlabel = *((u32 *)ipv6_hdr(skb));
  47
  48        ret = nft_do_chain(&pkt, priv);
  49        if (ret != NF_DROP && ret != NF_STOLEN &&
  50            (memcmp(&ipv6_hdr(skb)->saddr, &saddr, sizeof(saddr)) ||
  51             memcmp(&ipv6_hdr(skb)->daddr, &daddr, sizeof(daddr)) ||
  52             skb->mark != mark ||
  53             ipv6_hdr(skb)->hop_limit != hop_limit ||
  54             flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) {
  55                err = ip6_route_me_harder(state->net, skb);
  56                if (err < 0)
  57                        ret = NF_DROP_ERR(err);
  58        }
  59
  60        return ret;
  61}
  62
  63static const struct nft_chain_type nft_chain_route_ipv6 = {
  64        .name           = "route",
  65        .type           = NFT_CHAIN_T_ROUTE,
  66        .family         = NFPROTO_IPV6,
  67        .owner          = THIS_MODULE,
  68        .hook_mask      = (1 << NF_INET_LOCAL_OUT),
  69        .hooks          = {
  70                [NF_INET_LOCAL_OUT]     = nf_route_table_hook,
  71        },
  72};
  73
  74static int __init nft_chain_route_init(void)
  75{
  76        nft_register_chain_type(&nft_chain_route_ipv6);
  77
  78        return 0;
  79}
  80
  81static void __exit nft_chain_route_exit(void)
  82{
  83        nft_unregister_chain_type(&nft_chain_route_ipv6);
  84}
  85
  86module_init(nft_chain_route_init);
  87module_exit(nft_chain_route_exit);
  88
  89MODULE_LICENSE("GPL");
  90MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  91MODULE_ALIAS_NFT_CHAIN(AF_INET6, "route");
  92