* [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler
@ 2013-12-17 20:37 Daniel Borkmann
2013-12-17 21:57 ` Stephen Hemminger
2013-12-17 21:57 ` Stephen Hemminger
0 siblings, 2 replies; 4+ messages in thread
From: Daniel Borkmann @ 2013-12-17 20:37 UTC (permalink / raw)
To: davem; +Cc: shahed.shaikh, stephen, netdev
When adding a new vxlan device to an "underlying carrier" (here:
dst->remote_ifindex), the MTU size assigned to the vxlan device
is the MTU at setup time of the carrier - needed headroom, when
adding a vxlan device w/o explicit carrier, then it defaults
to 1500.
In case of an explicit carrier that supports jumbo frames, we
currently cannot change vxlan MTU via ip(8) to > 1500 in
post-setup time, as vxlan driver uses eth_change_mtu() as default
method for manually setting MTU.
Hence, use a custom implementation that only falls back to
eth_change_mtu() in case we didn't use a dev parameter on device
setup time, and otherwise allow a max MTU setting of the carrier
incl. adjustment for headroom.
Reported-by: Shahed Shaikh <shahed.shaikh@qlogic.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
---
v1->v2:
- applied Stephen's feedback
drivers/net/vxlan.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 58f6a0c..72466e9 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2014,6 +2014,30 @@ static void vxlan_set_multicast_list(struct net_device *dev)
{
}
+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;
+ int max_mtu;
+
+ lowerdev = __dev_get_by_index(dev_net(dev),
+ vxlan->default_dst.remote_ifindex);
+ if (lowerdev == NULL)
+ return eth_change_mtu(dev, new_mtu);
+
+ if (dst->remote_ip.sa.sa_family == AF_INET6)
+ max_mtu = lowerdev->mtu - VXLAN6_HEADROOM;
+ else
+ max_mtu = lowerdev->mtu - VXLAN_HEADROOM;
+
+ if (new_mtu < 68 || new_mtu > max_mtu)
+ return -EINVAL;
+
+ dev->mtu = new_mtu;
+ return 0;
+}
+
static const struct net_device_ops vxlan_netdev_ops = {
.ndo_init = vxlan_init,
.ndo_uninit = vxlan_uninit,
@@ -2022,7 +2046,7 @@ static const struct net_device_ops vxlan_netdev_ops = {
.ndo_start_xmit = vxlan_xmit,
.ndo_get_stats64 = ip_tunnel_get_stats64,
.ndo_set_rx_mode = vxlan_set_multicast_list,
- .ndo_change_mtu = eth_change_mtu,
+ .ndo_change_mtu = vxlan_change_mtu,
.ndo_validate_addr = eth_validate_addr,
.ndo_set_mac_address = eth_mac_addr,
.ndo_fdb_add = vxlan_fdb_add,
--
1.8.3.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler
2013-12-17 20:37 [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler Daniel Borkmann
@ 2013-12-17 21:57 ` Stephen Hemminger
2013-12-17 21:57 ` Stephen Hemminger
1 sibling, 0 replies; 4+ messages in thread
From: Stephen Hemminger @ 2013-12-17 21:57 UTC (permalink / raw)
To: Daniel Borkmann; +Cc: davem, shahed.shaikh, netdev
On Tue, 17 Dec 2013 21:37:40 +0100
Daniel Borkmann <dborkman@redhat.com> wrote:
> + struct vxlan_rdst *dst = &vxlan->default_dst;
This line is defined by never used.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler
2013-12-17 20:37 [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler Daniel Borkmann
2013-12-17 21:57 ` Stephen Hemminger
@ 2013-12-17 21:57 ` Stephen Hemminger
2013-12-17 21:59 ` Daniel Borkmann
1 sibling, 1 reply; 4+ messages in thread
From: Stephen Hemminger @ 2013-12-17 21:57 UTC (permalink / raw)
To: Daniel Borkmann; +Cc: davem, shahed.shaikh, netdev
On Tue, 17 Dec 2013 21:37:40 +0100
Daniel Borkmann <dborkman@redhat.com> wrote:
> + struct vxlan_rdst *dst = &vxlan->default_dst;
> + struct net_device *lowerdev;
> + int max_mtu;
> +
> + lowerdev = __dev_get_by_index(dev_net(dev),
> + vxlan->default_dst.remote_ifindex);
Actually, I meant that you should use dst->remote_ifindex here.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler
2013-12-17 21:57 ` Stephen Hemminger
@ 2013-12-17 21:59 ` Daniel Borkmann
0 siblings, 0 replies; 4+ messages in thread
From: Daniel Borkmann @ 2013-12-17 21:59 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: davem, shahed.shaikh, netdev
On 12/17/2013 10:57 PM, Stephen Hemminger wrote:
> On Tue, 17 Dec 2013 21:37:40 +0100
> Daniel Borkmann <dborkman@redhat.com> wrote:
>
>> + struct vxlan_rdst *dst = &vxlan->default_dst;
>> + struct net_device *lowerdev;
>> + int max_mtu;
>> +
>> + lowerdev = __dev_get_by_index(dev_net(dev),
>> + vxlan->default_dst.remote_ifindex);
>
> Actually, I meant that you should use dst->remote_ifindex here.
Ah, okay, was just wondering as it was used in dst->remote_ip.sa.sa_family.
Ok, will do, sure.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2013-12-17 20:37 [PATCH v2 net-next] net: vxlan: use custom ndo_change_mtu handler Daniel Borkmann
2013-12-17 21:57 ` Stephen Hemminger
2013-12-17 21:57 ` Stephen Hemminger
2013-12-17 21:59 ` Daniel Borkmann
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