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-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 12 Apr 2013 09:57:15 +0100
From:	Ian Campbell <Ian.Campbell@...rix.com>
To:	Wei Liu <wei.liu2@...rix.com>
CC:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"xen-devel@...ts.xen.org" <xen-devel@...ts.xen.org>,
	David Vrabel <david.vrabel@...rix.com>,
	"konrad.wilk@...cle.com" <konrad.wilk@...cle.com>,
	"annie.li@...cle.com" <annie.li@...cle.com>,
	"wdauchy@...il.com" <wdauchy@...il.com>
Subject: Re: [PATCH 5/7] xen-netfront: reduce gso_max_size to account for
 ethernet header

On Fri, 2013-04-12 at 09:48 +0100, Wei Liu wrote:
> On Fri, Apr 12, 2013 at 09:18:04AM +0100, Ian Campbell wrote:
> > On Thu, 2013-04-11 at 21:04 +0100, Wei Liu wrote:
> > > On Tue, Apr 09, 2013 at 12:07:33PM +0100, Wei Liu wrote:
> > > > The maximum packet including ethernet header that can be handled by netfront /
> > > > netback wire format is 65535. Reduce gso_max_size accordingly.
> > > > 
> > > > Drop skb and print warning when skb->len > 65535. This can 1) save the effort
> > > > to send malformed packet to netback, 2) help spotting misconfiguration of
> > > > netfront in the future.
> > > > 
> > > 
> > > Any opinion on how much space should be reserved? From a previous thread
> > > Ben seemed to suggest 90 (Ethernet + VLAN tag + IPv6 + TCP + timestamp
> > > option = 90 bytes).
> > 
> > I trust Ben and that seems as good as anything to me.
> > 
> > Is this the sort of limit others might be interested in, should we have
> > a global #define?
> > 
> 
> We shall have a global define in this case.
> 
> #define XEN_NETFRONT_MAX_HEADER ? I'm bad at naming things.

I meant an include/linux/skbuff.h (or some suitable header) #define
SKB_MAX_FOO type thing...

Ian.

--
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