From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Tue, 8 Oct 2019 09:56:03 +0000 (+0800)
Subject: ip6erspan: remove the incorrect mtu limit for ip6erspan
X-Git-Tag: v5.4-rc4~6^2~74
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4123f637a5129470ff9d3cb00a5a4e213f2e15cc;p=thirdparty%2Fkernel%2Flinux.git

ip6erspan: remove the incorrect mtu limit for ip6erspan

ip6erspan 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 ip6erspan tap
device.

Fixes: 61e84623ace3 ("net: centralize net_device min/max MTU checking")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index d5779d6a60650..787d9f2a6e990 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -2192,6 +2192,7 @@ static void ip6erspan_tap_setup(struct net_device *dev)
 {
 	ether_setup(dev);
 
+	dev->max_mtu = 0;
 	dev->netdev_ops = &ip6erspan_netdev_ops;
 	dev->needs_free_netdev = true;
 	dev->priv_destructor = ip6gre_dev_free;