From: Mark Tomlinson
Date: Wed, 19 Aug 2020 13:53:58 +1200
> When receiving an IPv4 packet inside an IPv6 GRE packet, and the
> IP6_TNL_F_RCV_DSCP_COPY flag is set on the tunnel, the IPv4 header would
> get corrupted. This is due to the common ip6_tnl_rcv() function assuming
> that the inner head
When receiving an IPv4 packet inside an IPv6 GRE packet, and the
IP6_TNL_F_RCV_DSCP_COPY flag is set on the tunnel, the IPv4 header would
get corrupted. This is due to the common ip6_tnl_rcv() function assuming
that the inner header is always IPv6. This patch checks the tunnel
protocol for IPv4 inn
