Merge branch 'tunnel-fixes'

Jesse Gross says:

====================
Tunneling fixes

This series fixes a problem that was reported where encapsulated packets
do not have their encapsulation offload markers stripped off when being
decapsulated. This causes a significant performance drop if the packets
are later retransmitted.

Fixing this revealed two other bugs which are also addressed as prerequisites:
 * GRO can aggregate packets for multiple layers of encapsulation which the
   stack cannot properly handle.
 * IPIP packets which are combined by GRO are not marked properly with their
   GSO type.

Note that this is based off the net-next tree as the current target for
bug fixes.

v2: No code changes, just additional information in commit messages and
    a new cover letter.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>