tree 6d244ccbf1e6bd4f304e24bd7cc6c52713400ac0
parent 47d77d464e574d56eecb39677df7bc6663635a3f
author Su Yanjun <suyj.fnst@cn.fujitsu.com> 1546828280 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1552511095 -0700

vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnel

[ Upstream commit dd9ee3444014e8f28c0eefc9fffc9ac9c5248c12 ]

Recently we run a network test over ipcomp virtual tunnel.We find that
if a ipv4 packet needs fragment, then the peer can't receive
it.

We deep into the code and find that when packet need fragment the smaller
fragment will be encapsulated by ipip not ipcomp. So when the ipip packet
goes into xfrm, it's skb->dev is not properly set. The ipv4 reassembly code
always set skb'dev to the last fragment's dev. After ipv4 defrag processing,
when the kernel rp_filter parameter is set, the skb will be drop by -EXDEV
error.

This patch adds compatible support for the ipip process in ipcomp virtual tunnel.

Signed-off-by: Su Yanjun <suyj.fnst@cn.fujitsu.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>