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
| ||
|
Date: Tue, 25 Nov 2014 20:01:13 -0800 From: Eric Dumazet <eric.dumazet@...il.com> To: David Miller <davem@...emloft.net> Cc: alexander.duyck@...il.com, alexander.h.duyck@...hat.com, netdev@...r.kernel.org, jeffrey.t.kirsher@...el.com Subject: Re: [net-next PATCH 2/5] ethernet/intel: Use eth_skb_pad helper On Tue, 2014-11-25 at 22:19 -0500, David Miller wrote: > From: Eric Dumazet <eric.dumazet@...il.com> > Date: Tue, 25 Nov 2014 17:43:05 -0800 > > > I believe I finally have an idea why we had various + 15 in skb > > allocations in TCP stack ! > > It was so that you could do one level of tunneling with "for > free". Or that is my recollection. > > Those + 15 existed way before any of these padto() calls even > existed. Well, tunneling is added in front of the packet. Thats why we use MAX_TCP_HEADER. The +15 is in fact because TCP stack wanted to make sure the eventual padding (needing tailroom, not headroom) was possible... Note that ack packets never used the +15, but other packets did. -- 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
Powered by blists - more mailing lists