tree 524c2182f1844a51abcf58e321094fc97f93edbc
parent 52a589d51f1008f62569bf89e95b26221ee76690
author Xin Long <lucien.xin@gmail.com> 1514184312 +0800
committer David S. Miller <davem@davemloft.net> 1514914574 -0500

ip6_tunnel: allow ip6gre dev mtu to be set below 1280

Commit 582442d6d5bc ("ipv6: Allow the MTU of ipip6 tunnel to be set
below 1280") fixed a mtu setting issue. It works for ipip6 tunnel.

But ip6gre dev updates the mtu also with ip6_tnl_change_mtu. Since
the inner packet over ip6gre can be ipv4 and it's mtu should also
be allowed to set below 1280, the same issue also exists on ip6gre.

This patch is to fix it by simply changing to check if parms.proto
is IPPROTO_IPV6 in ip6_tnl_change_mtu instead, to make ip6gre to
go to 'else' branch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>