From 39232973b779ab0c02cb6dcd8f819b7cb0fcd09a Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 26 Jan 2012 15:22:32 -0500 Subject: [PATCH] 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: David S. Miller --- net/ipv4/route.c | 5 +++++ net/ipv6/route.c | 16 +++++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index bcacf54e5418..4eeb8ce856e2 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -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) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 8c2e3ab58f2a..7d7f30697ead 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -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); -- 2.20.1