net/ipv6/netfilter.c

   1 #include <linux/config.h>
   2 #include <linux/init.h>
   3
   4 #ifdef CONFIG_NETFILTER
   5
   6 #include <linux/kernel.h>
   7 #include <linux/ipv6.h>
   8 #include <linux/netfilter.h>
   9 #include <linux/netfilter_ipv6.h>
  10 #include <net/dst.h>
  11 #include <net/ipv6.h>
  12 #include <net/ip6_route.h>
  13
  14 int ip6_route_me_harder(struct sk_buff *skb)
  15 {
  16         struct ipv6hdr *iph = skb->nh.ipv6h;
  17         struct dst_entry *dst;
  18         struct flowi fl = {
  19                 .oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
  20                 .nl_u =
  21                 { .ip6_u =
  22                   { .daddr = iph->daddr,
  23                     .saddr = iph->saddr, } },
  24                 .proto = iph->nexthdr,
  25         };
  26
  27         dst = ip6_route_output(skb->sk, &fl);
  28
  29         if (dst->error) {
  30                 IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
  31                 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
  32                 dst_release(dst);
  33                 return -EINVAL;
  34         }
  35
  36         /* Drop old route. */
  37         dst_release(skb->dst);
  38
  39         skb->dst = dst;
  40         return 0;
  41 }
  42 EXPORT_SYMBOL(ip6_route_me_harder);
  43
  44 /*
  45  * Extra routing may needed on local out, as the QUEUE target never
  46  * returns control to the table.
  47  */
  48
  49 struct ip6_rt_info {
  50         struct in6_addr daddr;
  51         struct in6_addr saddr;
  52 };
  53
  54 static void save(const struct sk_buff *skb, struct nf_info *info)
  55 {
  56         struct ip6_rt_info *rt_info = nf_info_reroute(info);
  57
  58         if (info->hook == NF_IP6_LOCAL_OUT) {
  59                 struct ipv6hdr *iph = skb->nh.ipv6h;
  60
  61                 rt_info->daddr = iph->daddr;
  62                 rt_info->saddr = iph->saddr;
  63         }
  64 }
  65
  66 static int reroute(struct sk_buff **pskb, const struct nf_info *info)
  67 {
  68         struct ip6_rt_info *rt_info = nf_info_reroute(info);
  69
  70         if (info->hook == NF_IP6_LOCAL_OUT) {
  71                 struct ipv6hdr *iph = (*pskb)->nh.ipv6h;
  72                 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
  73                     !ipv6_addr_equal(&iph->saddr, &rt_info->saddr))
  74                         return ip6_route_me_harder(*pskb);
  75         }
  76         return 0;
  77 }
  78
  79 static struct nf_queue_rerouter ip6_reroute = {
  80         .rer_size       = sizeof(struct ip6_rt_info),
  81         .save           = &save,
  82         .reroute        = &reroute,
  83 };
  84
  85 int __init ipv6_netfilter_init(void)
  86 {
  87         return nf_register_queue_rerouter(PF_INET6, &ip6_reroute);
  88 }
  89
  90 void ipv6_netfilter_fini(void)
  91 {
  92         nf_unregister_queue_rerouter(PF_INET6);
  93 }
  94
  95 #else /* CONFIG_NETFILTER */
  96 int __init ipv6_netfilter_init(void)
  97 {
  98         return 0;
  99 }
 100
 101 void ipv6_netfilter_fini(void)
 102 {
 103 }
 104 #endif /* CONFIG_NETFILTER */