From 0e141f757b2c78c983df893e9993313e2dc21e38 Mon Sep 17 00:00:00 2001 From: Haishuang Yan Date: Fri, 27 Sep 2019 14:58:20 +0800 Subject: [PATCH] erspan: remove the incorrect mtu limit for erspan 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: 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 Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index a53a543fe055..52690bb3e40f 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -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;