ip6_tunnel: fix ip6_tnl_lookup

ip6_tunnel: fix ip6_tnl_lookup

[ Upstream commit 68d00f332e0ba7f60f212be74ede290c9f873bc5 ]

The commit ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel
endpoints.") introduces support for wildcards in tunnels endpoints,
but in some rare circumstances ip6_tnl_lookup selects wrong tunnel
interface relying only on source or destination address of the packet
and not checking presence of wildcard in tunnels endpoints. Later in
ip6_tnl_rcv this packets can be dicarded because of difference in
ipproto even if fallback device have proper ipproto configuration.

This patch adds checks of wildcard endpoint in tunnel avoiding such
behavior

Fixes: ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel endpoints.")
Signed-off-by: Vadim Fedorenko <junk@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>