144 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			144 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * IPv6 specific functions of netfilter core
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|  *
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|  * Rusty Russell (C) 2000 -- This code is GPL.
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|  * Patrick McHardy (C) 2006-2012
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|  */
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| #include <linux/kernel.h>
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| #include <linux/init.h>
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| #include <linux/ipv6.h>
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| #include <linux/netfilter.h>
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| #include <linux/netfilter_ipv6.h>
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| #include <linux/export.h>
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| #include <net/addrconf.h>
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| #include <net/dst.h>
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| #include <net/ipv6.h>
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| #include <net/ip6_route.h>
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| #include <net/xfrm.h>
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| #include <net/netfilter/nf_queue.h>
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| 
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| int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff *skb)
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| {
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| 	const struct ipv6hdr *iph = ipv6_hdr(skb);
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| 	struct sock *sk = sk_to_full_sk(sk_partial);
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| 	struct net_device *dev = skb_dst(skb)->dev;
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| 	struct flow_keys flkeys;
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| 	unsigned int hh_len;
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| 	struct dst_entry *dst;
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| 	int strict = (ipv6_addr_type(&iph->daddr) &
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| 		      (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
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| 	struct flowi6 fl6 = {
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| 		.flowi6_l3mdev = l3mdev_master_ifindex(dev),
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| 		.flowi6_mark = skb->mark,
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| 		.flowi6_uid = sock_net_uid(net, sk),
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| 		.daddr = iph->daddr,
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| 		.saddr = iph->saddr,
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| 	};
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| 	int err;
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| 
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| 	if (sk && sk->sk_bound_dev_if)
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| 		fl6.flowi6_oif = sk->sk_bound_dev_if;
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| 	else if (strict)
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| 		fl6.flowi6_oif = dev->ifindex;
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| 
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| 	fib6_rules_early_flow_dissect(net, skb, &fl6, &flkeys);
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| 	dst = ip6_route_output(net, sk, &fl6);
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| 	err = dst->error;
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| 	if (err) {
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| 		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
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| 		net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
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| 		dst_release(dst);
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| 		return err;
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| 	}
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| 
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| 	/* Drop old route. */
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| 	skb_dst_drop(skb);
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| 
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| 	skb_dst_set(skb, dst);
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| 
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| #ifdef CONFIG_XFRM
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| 	if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
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| 	    xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
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| 		skb_dst_set(skb, NULL);
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| 		dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
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| 		if (IS_ERR(dst))
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| 			return PTR_ERR(dst);
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| 		skb_dst_set(skb, dst);
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| 	}
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| #endif
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| 
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| 	/* Change in oif may mean change in hh_len. */
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| 	hh_len = skb_dst(skb)->dev->hard_header_len;
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| 	if (skb_headroom(skb) < hh_len &&
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| 	    pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
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| 			     0, GFP_ATOMIC))
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| 		return -ENOMEM;
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL(ip6_route_me_harder);
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| 
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| static int nf_ip6_reroute(struct sk_buff *skb,
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| 			  const struct nf_queue_entry *entry)
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| {
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| 	struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
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| 
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| 	if (entry->state.hook == NF_INET_LOCAL_OUT) {
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| 		const struct ipv6hdr *iph = ipv6_hdr(skb);
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| 		if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
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| 		    !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
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| 		    skb->mark != rt_info->mark)
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| 			return ip6_route_me_harder(entry->state.net, entry->state.sk, skb);
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| 	}
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| 	return 0;
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| }
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| 
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| int __nf_ip6_route(struct net *net, struct dst_entry **dst,
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| 		   struct flowi *fl, bool strict)
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| {
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| 	static const struct ipv6_pinfo fake_pinfo;
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| 	static const struct inet_sock fake_sk = {
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| 		/* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
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| 		.sk.sk_bound_dev_if = 1,
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| 		.pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
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| 	};
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| 	const void *sk = strict ? &fake_sk : NULL;
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| 	struct dst_entry *result;
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| 	int err;
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| 
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| 	result = ip6_route_output(net, sk, &fl->u.ip6);
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| 	err = result->error;
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| 	if (err)
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| 		dst_release(result);
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| 	else
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| 		*dst = result;
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| 	return err;
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| }
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| EXPORT_SYMBOL_GPL(__nf_ip6_route);
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| 
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| static const struct nf_ipv6_ops ipv6ops = {
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| #if IS_MODULE(CONFIG_IPV6)
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| 	.chk_addr		= ipv6_chk_addr,
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| 	.route_me_harder	= ip6_route_me_harder,
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| 	.dev_get_saddr		= ipv6_dev_get_saddr,
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| 	.route			= __nf_ip6_route,
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| #endif
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| 	.route_input		= ip6_route_input,
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| 	.fragment		= ip6_fragment,
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| 	.reroute		= nf_ip6_reroute,
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| };
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| 
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| int __init ipv6_netfilter_init(void)
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| {
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| 	RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
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| 	return 0;
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| }
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| 
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| /* This can be called from inet6_init() on errors, so it cannot
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|  * be marked __exit. -DaveM
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|  */
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| void ipv6_netfilter_fini(void)
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| {
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| 	RCU_INIT_POINTER(nf_ipv6_ops, NULL);
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| }
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