[PATCH 3.14 32/68] vxlan: use dev->needed_headroom instead of dev->hard_header_len

Greg Kroah-Hartman
2014-06-24T16:22:03Z

From: Cong Wang <cwang@twopensource.com>

[ 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>
---
drivers/net/vxlan.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2282,9 +2282,9 @@ static void vxlan_setup(struct net_devic
eth_hw_addr_random(dev);
ether_setup(dev);
if (vxlan->default_dst.remote_ip.sa.sa_family == AF_INET6)
- dev->hard_header_len = ETH_HLEN + VXLAN6_HEADROOM;
+ dev->needed_headroom = ETH_HLEN + VXLAN6_HEADROOM;
else
- dev->hard_header_len = ETH_HLEN + VXLAN_HEADROOM;
+ dev->needed_headroom = ETH_HLEN + VXLAN_HEADROOM;

dev->netdev_ops = &vxlan_netdev_ops;
dev->destructor = free_netdev;
@@ -2667,8 +2667,7 @@ static int vxlan_newlink(struct net *net
if (!tb[IFLA_MTU])
dev->mtu = lowerdev->mtu - (use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);

- /* update header length based on lower device */
- dev->hard_header_len = lowerdev->hard_header_len +
+ dev->needed_headroom = lowerdev->hard_header_len +
(use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
} else if (use_ipv6)
vxlan->flags |= VXLAN_F_IPV6;