[PATCH next 2/3] blackhole_netdev: use blackhole_netdev to invalidate dst entries

[Mahesh Bandewar]

Use blackhole_netdev instead of 'lo' device with lower MTU when marking
dst "dead".

Signed-off-by: Mahesh Bandewar <mahe...@google.com>
---
 net/core/dst.c   | 2 +-
 net/ipv4/route.c | 3 +--
 net/ipv6/route.c | 2 +-
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/net/core/dst.c b/net/core/dst.c
index e46366228eaf..1325316d9eab 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -160,7 +160,7 @@ void dst_dev_put(struct dst_entry *dst)
                dst->ops->ifdown(dst, dev, true);
        dst->input = dst_discard;
        dst->output = dst_discard_out;
-       dst->dev = dev_net(dst->dev)->loopback_dev;
+       dst->dev = blackhole_netdev;
        dev_hold(dst->dev);
        dev_put(dev);
 }
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 66cbe8a7a168..049af0f88307 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1532,7 +1532,6 @@ static void ipv4_dst_destroy(struct dst_entry *dst)
 
 void rt_flush_dev(struct net_device *dev)
 {
-       struct net *net = dev_net(dev);
        struct rtable *rt;
        int cpu;
 
@@ -1543,7 +1542,7 @@ void rt_flush_dev(struct net_device *dev)
                list_for_each_entry(rt, &ul->head, rt_uncached) {
                        if (rt->dst.dev != dev)
                                continue;
-                       rt->dst.dev = net->loopback_dev;
+                       rt->dst.dev = blackhole_netdev;
                        dev_hold(rt->dst.dev);
                        dev_put(dev);
                }
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index c4d285fe0adc..335bcf812b25 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -176,7 +176,7 @@ static void rt6_uncached_list_flush_dev(struct net *net, 
struct net_device *dev)
                        }
 
                        if (rt_dev == dev) {
-                               rt->dst.dev = loopback_dev;
+                               rt->dst.dev = blackhole_netdev;
                                dev_hold(rt->dst.dev);
                                dev_put(rt_dev);
                        }
-- 
2.22.0.410.gd8fdbe21b5-goog