Commit 55e5bfb5 authored by David Wragg's avatar David Wragg Committed by David S. Miller

geneve: Relax MTU constraints

Allow the MTU of geneve devices to be set to large values, in order to
exploit underlying networks with larger frame sizes.

GENEVE does not have a fixed encapsulation overhead (an openvswitch
rule can add variable length options), so there is no relevant maximum
MTU to enforce.  A maximum of IP_MAX_MTU is used instead.
Encapsulated packets that are too big for the underlying network will
get dropped on the floor.
Signed-off-by: default avatarDavid Wragg <david@weave.works>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 72564b59
......@@ -1039,6 +1039,17 @@ static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
return geneve_xmit_skb(skb, dev, info);
}
static int geneve_change_mtu(struct net_device *dev, int new_mtu)
{
/* GENEVE overhead is not fixed, so we can't enforce a more
* precise max MTU.
*/
if (new_mtu < 68 || new_mtu > IP_MAX_MTU)
return -EINVAL;
dev->mtu = new_mtu;
return 0;
}
static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
struct ip_tunnel_info *info = skb_tunnel_info(skb);
......@@ -1083,7 +1094,7 @@ static const struct net_device_ops geneve_netdev_ops = {
.ndo_stop = geneve_stop,
.ndo_start_xmit = geneve_xmit,
.ndo_get_stats64 = ip_tunnel_get_stats64,
.ndo_change_mtu = eth_change_mtu,
.ndo_change_mtu = geneve_change_mtu,
.ndo_validate_addr = eth_validate_addr,
.ndo_set_mac_address = eth_mac_addr,
.ndo_fill_metadata_dst = geneve_fill_metadata_dst,
......
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