From: David Wragg <[email protected]>
Upstream commit:
Allow the MTU of vxlan devices without an underlying device to be set
to larger values (up to a maximum based on IP packet limits and vxlan
overhead).
Previously, their MTUs could not be set to higher than the
conventional ethernet value of 1500. This is a very arbitrary value
in the context of vxlan, and prevented vxlan devices from being able
to take advantage of jumbo frames etc.
The default MTU remains 1500, for compatibility.
Signed-off-by: David Wragg <[email protected]>
Acked-by: Roopa Prabhu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Upstream: 72564b59ffc4 ("vxlan: Relax MTU constraints")
Signed-off-by: Joe Stringer <[email protected]>
---
datapath/linux/compat/vxlan.c | 36 +++++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)
diff --git a/datapath/linux/compat/vxlan.c b/datapath/linux/compat/vxlan.c
index dd0015d01c32..f443a1b0352a 100644
--- a/datapath/linux/compat/vxlan.c
+++ b/datapath/linux/compat/vxlan.c
@@ -1608,29 +1608,43 @@ static void vxlan_set_multicast_list(struct net_device
*dev)
{
}
-static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
+static int __vxlan_change_mtu(struct net_device *dev,
+ struct net_device *lowerdev,
+ struct vxlan_rdst *dst, int new_mtu, bool strict)
{
- struct vxlan_dev *vxlan = netdev_priv(dev);
- struct vxlan_rdst *dst = &vxlan->default_dst;
- struct net_device *lowerdev;
- int max_mtu;
+ int max_mtu = IP_MAX_MTU;
- lowerdev = __dev_get_by_index(vxlan->net, dst->remote_ifindex);
- if (lowerdev == NULL)
- return eth_change_mtu(dev, new_mtu);
+ if (lowerdev)
+ max_mtu = lowerdev->mtu;
if (dst->remote_ip.sa.sa_family == AF_INET6)
- max_mtu = lowerdev->mtu - VXLAN6_HEADROOM;
+ max_mtu -= VXLAN6_HEADROOM;
else
- max_mtu = lowerdev->mtu - VXLAN_HEADROOM;
+ max_mtu -= VXLAN_HEADROOM;
- if (new_mtu < 68 || new_mtu > max_mtu)
+ if (new_mtu < 68)
return -EINVAL;
+ if (new_mtu > max_mtu) {
+ if (strict)
+ return -EINVAL;
+
+ new_mtu = max_mtu;
+ }
+
dev->mtu = new_mtu;
return 0;
}
+static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_rdst *dst = &vxlan->default_dst;
+ struct net_device *lowerdev = __dev_get_by_index(vxlan->net,
+ dst->remote_ifindex);
+ return __vxlan_change_mtu(dev, lowerdev, dst, new_mtu, true);
+}
+
static netdev_tx_t vxlan_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
/* Drop All packets coming from networking stack. OVS-CB is
--
2.1.4
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