vxlan: use dev->needed_headroom instead of dev->hard_header_len

[ Upstream commit 2853af6a2ea1a8ed09b09dd4fb578e7f435e8d34 ]

When we mirror packets from a vxlan tunnel to other device,
the mirror device should see the same packets (that is, without
outer header). Because vxlan tunnel sets dev->hard_header_len,
tcf_mirred() resets mac header back to outer mac, the mirror device
actually sees packets with outer headers

Vxlan tunnel should set dev->needed_headroom instead of
dev->hard_header_len, like what other ip tunnels do. This fixes
the above problem.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: stephen hemminger <stephen@networkplumber.org>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 9673edfff4512d5220a1971855aaaf8cdf9c7600..fcbd4eee52cc7e1403e098dfffa5ea6a9cc331d1 100644 (file)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1314,7 +1314,7 @@ static void vxlan_setup(struct net_device *dev)
 
        eth_hw_addr_random(dev);
        ether_setup(dev);
-       dev->hard_header_len = ETH_HLEN + VXLAN_HEADROOM;
+       dev->needed_headroom = ETH_HLEN + VXLAN_HEADROOM;
 
        dev->netdev_ops = &vxlan_netdev_ops;
        dev->destructor = vxlan_free;
@@ -1454,7 +1454,7 @@ static int vxlan_newlink(struct net *net, struct net_device *dev,
                        dev->mtu = lowerdev->mtu - VXLAN_HEADROOM;
 
                /* update header length based on lower device */
-               dev->hard_header_len = lowerdev->hard_header_len +
+               dev->needed_headroom = lowerdev->hard_header_len +
                                       VXLAN_HEADROOM;
        }