Commit 39232973 authored by David S. Miller's avatar David S. Miller
Browse files

ipv4/ipv6: Prepare for new route gateway semantics. 



In the future the ipv4/ipv6 route gateway will take on two types
of values:

1) INADDR_ANY/IN6ADDR_ANY, for local network routes, and in this case
   the neighbour must be obtained using the destination address in
   ipv4/ipv6 header as the lookup key.

2) Everything else, the actual nexthop route address.

So if the gateway is not inaddr-any we use it, otherwise we must use
the packet's destination address.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 09e9b813

net/ipv4/route.c

+5 −0
Original line number Diff line number Diff line
@@ -1117,10 +1117,15 @@ static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const vo 
	static const __be32 inaddr_any = 0;

	struct net_device *dev = dst->dev;

	const __be32 *pkey = daddr;

	const struct rtable *rt;

	struct neighbour *n;



	rt = (const struct rtable *) dst;



	if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))

		pkey = &inaddr_any;

	else if (rt->rt_gateway)

		pkey = (const __be32 *) &rt->rt_gateway;



	n = __ipv4_neigh_lookup(&arp_tbl, dev, *(__force u32 *)pkey);

	if (n)

net/ipv6/route.c

+15 −1
Original line number Diff line number Diff line
@@ -121,9 +121,23 @@ static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old) 
	return p;

}



static inline const void *choose_neigh_daddr(struct rt6_info *rt, const void *daddr)

{

	struct in6_addr *p = &rt->rt6i_gateway;



	if (p->s6_addr32[0] | p->s6_addr32[1] |

	    p->s6_addr32[2] | p->s6_addr32[3])

		return (const void *) p;

	return daddr;

}



static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst, const void *daddr)

{

	struct neighbour *n = __ipv6_neigh_lookup(&nd_tbl, dst->dev, daddr);

	struct rt6_info *rt = (struct rt6_info *) dst;

	struct neighbour *n;



	daddr = choose_neigh_daddr(rt, daddr);

	n = __ipv6_neigh_lookup(&nd_tbl, dst->dev, daddr);

	if (n)

		return n;

	return neigh_create(&nd_tbl, daddr, dst->dev);

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