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From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: jamie.gloudon@gmail.com, netdev@vger.kernel.org
Subject: Re: [PATCH net-next] net: more accurate network taps in transmit path
Date: Wed, 19 Sep 2012 14:16:37 -0400 (EDT)	[thread overview]
Message-ID: <20120919.141637.531173978256020103.davem@davemloft.net> (raw)
In-Reply-To: <1348037089.26523.397.camel@edumazet-glaptop>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 19 Sep 2012 08:44:49 +0200

> From: Eric Dumazet <edumazet@google.com>
> 
> dev_queue_xmit_nit() should be called right before ndo_start_xmit()
> calls or we might give wrong packet contents to taps users :
> 
> Packet checksum can be changed, or packet can be linearized or
> segmented, and segments partially sent for the later case.
> 
> Also a memory allocation can fail and packet never really hit the
> driver entry point.
> 
> Reported-by: Jamie Gloudon <jamie.gloudon@gmail.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Are you really sure that all the network tap implementations can
handle software GSO segmented skbs using skb->next linkage?

Because that is what they can potentially see after this change.

  parent reply	other threads:[~2012-09-19 18:16 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20120918193208.GA19030@darkstar>
     [not found] ` <1347998905.2685.29.camel@bwh-desktop.uk.solarflarecom.com>
2012-09-18 21:14   ` BUG: TCPDUMP invalid cksum persists after disabling TCP cksum offload Jamie Gloudon
2012-09-18 21:46     ` Vijay Subramanian
2012-09-18 21:54       ` Rick Jones
2012-09-18 22:20         ` Jamie Gloudon
2012-09-19  5:54     ` Eric Dumazet
2012-09-19  6:44       ` [PATCH net-next] net: more accurate network taps in transmit path Eric Dumazet
2012-09-19 15:58         ` Jamie Gloudon
2012-09-19 18:16         ` David Miller [this message]
2012-09-19 18:21           ` Eric Dumazet
2012-09-19 19:33             ` David Miller

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