* Alexandr Nedvedicky <[email protected]> [2015-09-29 12:17]: > I have not looked at current checksum handling at PF on OpenBSD, so can't tell > exactly what's going on there. I feel PF does not bother too much with > updating > the checksum, when it changes the packet. It seems to me the > in_proto_cksum_out() gets called as soon as outbound packet gets inspected by > pf_test() to calculate/fix checksums. It looks like in_proto_cksum_out() has > to > recalculate checksum in SW for entire packet, when underlying HW does not > offer > checksum offload. Is that right? Or am I missing some piece?
Basically. Packets that are modified by pf or are locally originated get "needs checksumming" flags (there are a few actually). in_proto_cksum_out basically emulates the hw cksum engine if we don't have one. I consider having one the norm these days. -- Henning Brauer, [email protected], [email protected] BS Web Services GmbH, http://bsws.de, Full-Service ISP Secure Hosting, Mail and DNS. Virtual & Dedicated Servers, Root to Fully Managed Henning Brauer Consulting, http://henningbrauer.com/
