diff options
| author | David Wragg | 2016-02-10 00:05:55 +0000 |
|---|---|---|
| committer | David S. Miller | 2016-02-10 05:50:03 -0500 |
| commit | 72564b59ffc438ea103b0727a921aaddce766728 (patch) | |
| tree | cc32571d466df92c568e8b879a19fe5b3de30576 /drivers | |
| parent | 461547f3158978c180d74484d58e82be9b8e7357 (diff) | |
vxlan: Relax MTU constraints
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 <david@weave.works>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/vxlan.c | 36 |
1 files changed, 25 insertions, 11 deletions
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 65439188c582..e992c6a05f86 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -2367,29 +2367,43 @@ 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 int egress_ipv4_tun_info(struct net_device *dev, struct sk_buff *skb, struct ip_tunnel_info *info, __be16 sport, __be16 dport) |