[IPV4]: Store idev in routes.

include/net/route.h

@@ -55,6 +55,8 @@ struct rtable
 		struct rtable		*rt_next;
 	} u;
 
+	struct in_device	*idev;
+	
 	unsigned		rt_flags;
 	unsigned		rt_type;
 

net/ipv4/route.c

@@ -1040,6 +1040,8 @@ void ip_rt_redirect(u32 old_gw, u32 daddr, u32 new_gw,
 				rt->u.dst.child		= NULL;
 				if (rt->u.dst.dev)
 					dev_hold(rt->u.dst.dev);
+				if (rt->idev)
+					in_dev_hold(rt->idev);
 				rt->u.dst.obsolete	= 0;
 				rt->u.dst.lastuse	= jiffies;
 				rt->u.dst.path		= &rt->u.dst;
@@ -1321,11 +1323,17 @@ static void ipv4_dst_destroy(struct dst_entry *dst)
 {
 	struct rtable *rt = (struct rtable *) dst;
 	struct inet_peer *peer = rt->peer;
+	struct in_device *idev = rt->idev;
 
 	if (peer) {
 		rt->peer = NULL;
 		inet_putpeer(peer);
 	}
+
+	if (idev) {
+		rt->idev = NULL;
+		in_dev_put(idev);
+	}
 }
 
 static void ipv4_link_failure(struct sk_buff *skb)
@@ -1486,6 +1494,7 @@ static int ip_route_input_mc(struct sk_buff *skb, u32 daddr, u32 saddr,
 	rth->fl.iif	= dev->ifindex;
 	rth->u.dst.dev	= &loopback_dev;
 	dev_hold(rth->u.dst.dev);
+	rth->idev	= in_dev_get(rth->u.dst.dev);
 	rth->fl.oif	= 0;
 	rth->rt_gateway	= daddr;
 	rth->rt_spec_dst= spec_dst;
@@ -1695,6 +1704,7 @@ static int ip_route_input_slow(struct sk_buff *skb, u32 daddr, u32 saddr,
 	rth->fl.iif	= dev->ifindex;
 	rth->u.dst.dev	= out_dev->dev;
 	dev_hold(rth->u.dst.dev);
+	rth->idev	= in_dev_get(rth->u.dst.dev);
 	rth->fl.oif 	= 0;
 	rth->rt_spec_dst= spec_dst;
 
@@ -1774,6 +1784,7 @@ out:	return err;
 	rth->fl.iif	= dev->ifindex;
 	rth->u.dst.dev	= &loopback_dev;
 	dev_hold(rth->u.dst.dev);
+	rth->idev	= in_dev_get(rth->u.dst.dev);
 	rth->rt_gateway	= daddr;
 	rth->rt_spec_dst= spec_dst;
 	rth->u.dst.input= ip_local_deliver;
@@ -2157,6 +2168,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
 	rth->rt_iif	= oldflp->oif ? : dev_out->ifindex;
 	rth->u.dst.dev	= dev_out;
 	dev_hold(dev_out);
+	rth->idev	= in_dev_get(dev_out);
 	rth->rt_gateway = fl.fl4_dst;
 	rth->rt_spec_dst= fl.fl4_src;