On Mon, 19 Sep 2022, at 11:55, shaozhengchao wrote: > Sorry for the delay. I'm busy testing the TC module recently. I'm very > sorry for the user-space breakage. > > The root cause of this problem is that eth_type_trans() is called when > the protocol type of the SKB is parsed. The len value of the SKB is > reduced to 0. If the user mode requires that the forwarding succeed, or > if the MAC header is added again after the MAC header is subtracted, > is this appropriate? We don't require forwarding to succeed with a 14 byte input buffer. We also don't look at the MAC header. I think refusing to forward 0 length packets would be OK. Not 100% certain I understood you correctly, let me know if this helps. Best Lorenz
