ipv4: Adjust semantics of rt->rt_gateway.

In order to allow prefixed routes, we have to adjust how rt_gateway
is set and interpreted.

The new interpretation is:

1) rt_gateway == 0, destination is on-link, nexthop is iph->daddr

2) rt_gateway != 0, destination requires a nexthop gateway

Abstract the fetching of the proper nexthop value using a new
inline helper, rt_nexthop(), as suggested by Joe Perches.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Vijay Subramanian <subramanian.vijay@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 2c2c35bace76..99af1f0cc658 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -487,7 +487,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
                         dev->stats.tx_fifo_errors++;
                         goto tx_error;
                 }
-                dst = rt->rt_gateway;
+                dst = rt_nexthop(rt, old_iph->daddr);
         }
 
         rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,