netdev - Questions about CHECKSUM

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 linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAF5V5FbthBZ3QFzCUVov8MZ9TgF=+B6XM3eR+cyizbzcT-6v-A@mail.gmail.com>
Date:	Thu, 20 Oct 2011 23:05:25 -0400
From:	fengcheng lu <sparking.lu@...il.com>
To:	netdev@...r.kernel.org
Subject: Questions about CHECKSUM_COMPLETE

Hello everyone

I have one question about the CHECKSUM_COMPLETE. When
CHECK_SUM_COMPLETE is set, which data does the skb->csum computed by
hardware cover?

I thought skb->csum only covers the Transport header (e.g. TCP/UDP) +
Transport payload + pseudo header. However, after I read the vlan
codes (vlan_skb_recv in the vlan_dev.c of linux kernel 2.6.27.19), I
become confuse.

The vlan_skb_recv calls skb_pull_rcsum which updates the skb->csum if
CHECKSUM_COMPLETE is set. It implies the vlan  header is also covered
by the skb->csum. so I wonder if the skb->csum cover the whole data
besides the eth header (14 bytes).

Thanks
Steven Lu
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html