net: Add ->neigh_lookup() operation to dst_ops
In the future dst entries will be neigh-less. In that environment we
need to have an easy transition point for current users of
dst->neighbour outside of the packet output fast path.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1d4cd3b..3313730 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -185,6 +185,8 @@
return p;
}
+static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
+
static struct dst_ops ipv4_dst_ops = {
.family = AF_INET,
.protocol = cpu_to_be16(ETH_P_IP),
@@ -199,6 +201,7 @@
.link_failure = ipv4_link_failure,
.update_pmtu = ip_rt_update_pmtu,
.local_out = __ip_local_out,
+ .neigh_lookup = ipv4_neigh_lookup,
};
#define ECN_OR_COST(class) TC_PRIO_##class
@@ -1008,22 +1011,30 @@
return length >> FRACT_BITS;
}
-static int rt_bind_neighbour(struct rtable *rt)
+static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
{
- static const __be32 inaddr_any = 0;
- struct net_device *dev = rt->dst.dev;
struct neigh_table *tbl = &arp_tbl;
- const __be32 *nexthop;
+ static const __be32 inaddr_any = 0;
+ struct net_device *dev = dst->dev;
+ const __be32 *pkey = daddr;
struct neighbour *n;
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
if (dev->type == ARPHRD_ATM)
tbl = clip_tbl_hook;
#endif
- nexthop = &rt->rt_gateway;
if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
- nexthop = &inaddr_any;
- n = ipv4_neigh_lookup(tbl, dev, nexthop);
+ pkey = &inaddr_any;
+
+ n = __ipv4_neigh_lookup(tbl, dev, *(__force u32 *)pkey);
+ if (n)
+ return n;
+ return neigh_create(tbl, pkey, dev);
+}
+
+static int rt_bind_neighbour(struct rtable *rt)
+{
+ struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
if (IS_ERR(n))
return PTR_ERR(n);
dst_set_neighbour(&rt->dst, n);
@@ -2734,6 +2745,7 @@
.default_advmss = ipv4_default_advmss,
.update_pmtu = ipv4_rt_blackhole_update_pmtu,
.cow_metrics = ipv4_rt_blackhole_cow_metrics,
+ .neigh_lookup = ipv4_neigh_lookup,
};
struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)