ipv6: Refactor fib6_ignore_linkdown

fib6_ignore_linkdown takes a fib6_info but only looks at the net_device
and its IPv6 config. Change it to take a net_device over a fib6_info as
its input argument.

In addition, move it to a header file to make the check inline and usable
later with IPv4 code without going through the ipv6 stub, and rename to
ip6_ignore_linkdown since it is only checking the setting based on the
ipv6 struct on a device.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/addrconf.h

@@ -425,6 +425,14 @@ static inline void in6_dev_hold(struct inet6_dev *idev)
 	refcount_inc(&idev->refcnt);
 }
 
+/* called with rcu_read_lock held */
+static inline bool ip6_ignore_linkdown(const struct net_device *dev)
+{
+	const struct inet6_dev *idev = __in6_dev_get(dev);
+
+	return !!idev->cnf.ignore_routes_with_linkdown;
+}
+
 void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp);
 
 static inline void in6_ifa_put(struct inet6_ifaddr *ifp)

net/ipv6/route.c

@@ -639,21 +639,6 @@ static int rt6_score_route(struct fib6_info *rt, int oif, int strict)
 	return m;
 }
 
-/* called with rc_read_lock held */
-static inline bool fib6_ignore_linkdown(const struct fib6_info *f6i)
-{
-	const struct net_device *dev = fib6_info_nh_dev(f6i);
-	bool rc = false;
-
-	if (dev) {
-		const struct inet6_dev *idev = __in6_dev_get(dev);
-
-		rc = !!idev->cnf.ignore_routes_with_linkdown;
-	}
-
-	return rc;
-}
-
 static struct fib6_info *find_match(struct fib6_info *rt, int oif, int strict,
 				   int *mpri, struct fib6_info *match,
 				   bool *do_rr)
@@ -664,7 +649,7 @@ static struct fib6_info *find_match(struct fib6_info *rt, int oif, int strict,
 	if (rt->fib6_nh.nh_flags & RTNH_F_DEAD)
 		goto out;
 
-	if (fib6_ignore_linkdown(rt) &&
+	if (ip6_ignore_linkdown(rt->fib6_nh.nh_dev) &&
 	    rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN &&
 	    !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 		goto out;
@@ -3875,7 +3860,7 @@ static bool rt6_is_dead(const struct fib6_info *rt)
 {
 	if (rt->fib6_nh.nh_flags & RTNH_F_DEAD ||
 	    (rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN &&
-	     fib6_ignore_linkdown(rt)))
+	     ip6_ignore_linkdown(rt->fib6_nh.nh_dev)))
 		return true;
 
 	return false;
@@ -4608,7 +4593,7 @@ static int rt6_nexthop_info(struct sk_buff *skb, struct fib6_info *rt,
 		*flags |= RTNH_F_LINKDOWN;
 
 		rcu_read_lock();
-		if (fib6_ignore_linkdown(rt))
+		if (ip6_ignore_linkdown(rt->fib6_nh.nh_dev))
 			*flags |= RTNH_F_DEAD;
 		rcu_read_unlock();
 	}