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

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

drivers/net/geneve.c

+12 −1
Original line number Original line Diff line number Diff line
@@ -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);

	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)

static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)

{

{

	struct ip_tunnel_info *info = skb_tunnel_info(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_stop		= geneve_stop,

	.ndo_start_xmit		= geneve_xmit,

	.ndo_start_xmit		= geneve_xmit,

	.ndo_get_stats64	= ip_tunnel_get_stats64,

	.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_validate_addr	= eth_validate_addr,

	.ndo_set_mac_address	= eth_mac_addr,

	.ndo_set_mac_address	= eth_mac_addr,

	.ndo_fill_metadata_dst	= geneve_fill_metadata_dst,

	.ndo_fill_metadata_dst	= geneve_fill_metadata_dst,

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