lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sat, 22 Oct 2022 12:51:26 -0700 From: Cong Wang <xiyou.wangcong@...il.com> To: "J.J. Mars" <mars14850@...il.com> Cc: netdev@...r.kernel.org Subject: Re: Confused about ip_summed member in sk_buff On Fri, Oct 21, 2022 at 02:29:26PM +0800, J.J. Mars wrote: > Hi everyone, I'm new here and I hope this mail won't disturb you :) > > Recently I was working with something about ip_summed, and I'm really > confused about the question what does ip_summed exactly mean? > This member is defined with comment Driver fed us an IP checksum'. So > I guess it's about IP/L3 checksum status. > But the possible value of ip_summed like CHECKSUM_UNNECESSARY is about L4. > > What confused me a lot is ip_summed seems to tell us the checksum of > IP/L3 layer is available from its name. > But it seems to tell us the checksum status of L4 layer from its value. > > Besides, in ip_rcv() it seems the ip_summed is not used before > calculating the checksum of IP header. > > So does ip_summed indicate the status of L3 checksum status or L4 > checksum status? > If L4, why is it named like that? The name itself is indeed confusing, however, there are some good explanations in the code, at the beginning of include/linux/skbuff.h. I think that could help you to clear your confusions here. Thanks.
Powered by blists - more mailing lists