On Tue, Jan 23, 2018 at 10:59:49AM +0100, Matthias Schiffer wrote: > eth_type_trans() internally calls skb_pull(), which does not adjust the > skb checksum; skb_postpull_rcsum() is necessary to avoid log spam of the > form "bat0: hw csum failure" when packets with CHECKSUM_COMPLETE are > received. > > Note that in usual setups, packets don't reach batman-adv with > CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see > batadv's ethtype?), which is why the log messages do nor occur on every > system using batman-adv. I could reproduce this issue by stacking > batman-adv on top of a VXLAN interface. > > Signed-off-by: Matthias Schiffer <mschif...@universe-factory.net>
Seems reasonable, this change. I'm just a little confused though: Two years ago someone had reported checksumming errors with a Raspberry Pi and batman-adv: https://www.open-mesh.org/issues/224 And they seemed to be gone in newer kernel versions, while hardware checksumming was supposedly still enabled. Are the issues reproduceable without using VXLANs (for instance on a Pi1 or Pi2)? Are they reproduceable on a recent kernel version? (I guess you tested with a 4.4 kernel?) Regards, Linus
