From: Haishuang Yan yanhaishuang@cmss.chinamobile.com
[ Upstream commit 0e141f757b2c78c983df893e9993313e2dc21e38 ]
erspan driver calls ether_setup(), after commit 61e84623ace3 ("net: centralize net_device min/max MTU checking"), the range of mtu is [min_mtu, max_mtu], which is [68, 1500] by default.
It causes the dev mtu of the erspan device to not be greater than 1500, this limit value is not correct for ipgre tap device.
Tested: Before patch: # ip link set erspan0 mtu 1600 Error: mtu greater than device maximum. After patch: # ip link set erspan0 mtu 1600 # ip -d link show erspan0 21: erspan0@NONE: <BROADCAST,MULTICAST> mtu 1600 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 0
Fixes: 61e84623ace3 ("net: centralize net_device min/max MTU checking") Signed-off-by: Haishuang Yan yanhaishuang@cmss.chinamobile.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/ip_gre.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -1424,6 +1424,7 @@ nla_put_failure: static void erspan_setup(struct net_device *dev) { ether_setup(dev); + dev->max_mtu = 0; dev->netdev_ops = &erspan_netdev_ops; dev->priv_flags &= ~IFF_TX_SKB_SHARING; dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;