ip_tunnel: fix ip tunnel lookup in collect_md mode

In collect_md mode, if the tun dev is down, it still can call
ip_tunnel_rcv to receive on packets, and the rx statistics increase
improperly.

When the md tunnel is down, it's not neccessary to increase RX drops
for the tunnel device, packets would be recieved on fallback tunnel,
and the RX drops on fallback device will be increased as expected.

Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index e1856bfa753da40a35a34bf71610ebc22059afc8..e9805ad664ac24c3405ad015cfaab89dc1c95279 100644 (file)
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -176,7 +176,7 @@ skip_key_lookup:
                return cand;
 
        t = rcu_dereference(itn->collect_md_tun);
-       if (t)
+       if (t && t->dev->flags & IFF_UP)
                return t;
 
        if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP)