Commit 0e141f75 authored Sep 27, 2019 by Haishuang Yan Committed by David S. Miller Sep 30, 2019

erspan: remove the incorrect mtu limit for erspan



erspan driver calls ether_setup(), after commit 61e84623
("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: 61e84623 ("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>

parent e9789c7c

net/ipv4/ip_gre.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1446,6 +1446,7 @@ static void erspan_setup(struct net_device *dev)
		struct ip_tunnel *t = netdev_priv(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;

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