diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2016-07-14 18:00:10 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-07-16 20:15:02 -0700 |
| commit | 18d3df3eab23796d7f852f9c6bb60962b8372ced (patch) | |
| tree | 4871d69274a682be6379696208efafc622d3234d /net/8021q/vlan_netlink.c | |
| parent | e86663c475d384ab5f46cb5637e9b7ad08c5c505 (diff) | |
vlan: use a valid default mtu value for vlan over macsec
macsec can't cope with mtu frames which need vlan tag insertion, and
vlan device set the default mtu equal to the underlying dev's one.
By default vlan over macsec devices use invalid mtu, dropping
all the large packets.
This patch adds a netif helper to check if an upper vlan device
needs mtu reduction. The helper is used during vlan devices
initialization to set a valid default and during mtu updating to
forbid invalid, too bit, mtu values.
The helper currently only check if the lower dev is a macsec device,
if we get more users, we need to update only the helper (possibly
reserving an additional IFF bit).
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/8021q/vlan_netlink.c')
| -rw-r--r-- | net/8021q/vlan_netlink.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c index c92b52f37d38..1270207f3d7c 100644 --- a/net/8021q/vlan_netlink.c +++ b/net/8021q/vlan_netlink.c @@ -118,6 +118,7 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev, { struct vlan_dev_priv *vlan = vlan_dev_priv(dev); struct net_device *real_dev; + unsigned int max_mtu; __be16 proto; int err; @@ -144,9 +145,11 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev, if (err < 0) return err; + max_mtu = netif_reduces_vlan_mtu(real_dev) ? real_dev->mtu - VLAN_HLEN : + real_dev->mtu; if (!tb[IFLA_MTU]) - dev->mtu = real_dev->mtu; - else if (dev->mtu > real_dev->mtu) + dev->mtu = max_mtu; + else if (dev->mtu > max_mtu) return -EINVAL; err = vlan_changelink(dev, tb, data); |