lkml.org 
[lkml]   [2000]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: zero-copy TCP
On Sun, Sep 03, 2000 at 07:42:53PM +0200, Ingo Molnar wrote:
>
> On Sun, 3 Sep 2000, Andi Kleen wrote:
>
> > You can already cause incorrect checksums on the wire just by passing
> > a partly unmapped address (the zero-the-rest exception handler in
> > csum_copy_generic in i386 forgets to add in the carry)
> >
> > I do not believe it is a big deal, packets with bad checksum are not
> > really a problem (you can usually do other better DoS that do not need
> > it)
>
> i think it's a quality of implementation issue. The csum_copy_generic
> thing is a bug. Allowing incorrect checksums to be sent out would be a

From brief inspection at least arm, mips, m68k have similar problems.

[haven't checked the others]

> design bug. I think some RFCs do even forbid the sending of incorrect
> packets?

I do not know any that do. Of course you shouldn't, but the receiver
has to handle it anyways.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:38    [W:0.097 / U:9.164 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site