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- /*
- * IPv6 specific functions of netfilter core
- *
- * Rusty Russell (C) 2000 -- This code is GPL.
- * Patrick McHardy (C) 2006-2012
- */
- #include <linux/kernel.h>
- #include <linux/init.h>
- #include <linux/ipv6.h>
- #include <linux/netfilter.h>
- #include <linux/netfilter_ipv6.h>
- #include <linux/export.h>
- #include <net/addrconf.h>
- #include <net/dst.h>
- #include <net/ipv6.h>
- #include <net/ip6_route.h>
- #include <net/xfrm.h>
- #include <net/netfilter/nf_queue.h>
- int ip6_route_me_harder(struct net *net, struct sk_buff *skb)
- {
- const struct ipv6hdr *iph = ipv6_hdr(skb);
- struct sock *sk = sk_to_full_sk(skb->sk);
- unsigned int hh_len;
- struct dst_entry *dst;
- int strict = (ipv6_addr_type(&iph->daddr) &
- (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
- struct flowi6 fl6 = {
- .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
- strict ? skb_dst(skb)->dev->ifindex : 0,
- .flowi6_mark = skb->mark,
- .flowi6_uid = sock_net_uid(net, sk),
- .daddr = iph->daddr,
- .saddr = iph->saddr,
- };
- int err;
- dst = ip6_route_output(net, sk, &fl6);
- err = dst->error;
- if (err) {
- IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
- net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
- dst_release(dst);
- return err;
- }
- /* Drop old route. */
- skb_dst_drop(skb);
- skb_dst_set(skb, dst);
- #ifdef CONFIG_XFRM
- if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
- xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
- skb_dst_set(skb, NULL);
- dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
- if (IS_ERR(dst))
- return PTR_ERR(dst);
- skb_dst_set(skb, dst);
- }
- #endif
- /* Change in oif may mean change in hh_len. */
- hh_len = skb_dst(skb)->dev->hard_header_len;
- if (skb_headroom(skb) < hh_len &&
- pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
- 0, GFP_ATOMIC))
- return -ENOMEM;
- return 0;
- }
- EXPORT_SYMBOL(ip6_route_me_harder);
- static int nf_ip6_reroute(struct sk_buff *skb,
- const struct nf_queue_entry *entry)
- {
- struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
- if (entry->state.hook == NF_INET_LOCAL_OUT) {
- const struct ipv6hdr *iph = ipv6_hdr(skb);
- if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
- !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
- skb->mark != rt_info->mark)
- return ip6_route_me_harder(entry->state.net, skb);
- }
- return 0;
- }
- static int nf_ip6_route(struct net *net, struct dst_entry **dst,
- struct flowi *fl, bool strict)
- {
- static const struct ipv6_pinfo fake_pinfo;
- static const struct inet_sock fake_sk = {
- /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
- .sk.sk_bound_dev_if = 1,
- .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
- };
- const void *sk = strict ? &fake_sk : NULL;
- struct dst_entry *result;
- int err;
- result = ip6_route_output(net, sk, &fl->u.ip6);
- err = result->error;
- if (err)
- dst_release(result);
- else
- *dst = result;
- return err;
- }
- static const struct nf_ipv6_ops ipv6ops = {
- .chk_addr = ipv6_chk_addr,
- .route_input = ip6_route_input,
- .fragment = ip6_fragment,
- .route = nf_ip6_route,
- .reroute = nf_ip6_reroute,
- };
- int __init ipv6_netfilter_init(void)
- {
- RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
- return 0;
- }
- /* This can be called from inet6_init() on errors, so it cannot
- * be marked __exit. -DaveM
- */
- void ipv6_netfilter_fini(void)
- {
- RCU_INIT_POINTER(nf_ipv6_ops, NULL);
- }
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