From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: Ben Greear <greearb@candelatech.com>,
jeffrey.t.kirsher@intel.com, Jeff Kirsher <tarbal@gmail.com>,
netdev@vger.kernel.org
Subject: RE: [PATCH v2 00/10] Low-level Ethernet debugging features.
Date: Fri, 10 Feb 2012 14:51:37 +0100 [thread overview]
Message-ID: <1328881897.2443.20.camel@edumazet-laptop> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6026B6E6A@saturn3.aculab.com>
Le vendredi 10 février 2012 à 13:45 +0000, David Laight a écrit :
> > > I was thinking I might could get at least some NICs to generate Runt
> frames
> > > by sending small pkts and disabling frame padding, but haven't
> looked into
> > > it too hard yet.
> >
> > I am interested by this, do you know some NICs able to disable frame
> > padding ?
>
> I'm reasonably sure some old NICs like the AMD lance will send runts.
> Quite likely any that require the drives to set the padded frame length.
>
> The same will be true when semi-generic HDLC controllers are used
> to send packets from DSPs, FPGAs and SOCs.
>
Apparently, drivers/net/ethernet/dlink/de620.c does this in its
de620_start_xmit() function :
if ((len = skb->len) < RUNT)
len = RUNT;
Thats interesting for two reasons :
1) We probably can remove the test to send runts if we want to test
things...
2) As is, we can leak kernel memory content to wire since we dont
initialize the padding data.
next prev parent reply other threads:[~2012-02-10 13:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-08 19:54 [PATCH v2 00/10] Low-level Ethernet debugging features greearb
2012-02-08 19:54 ` [PATCH v2 01/10] net: Support RXFCS feature flag greearb
2012-02-08 19:54 ` [PATCH v2 02/10] e100: " greearb
2012-02-10 22:56 ` Michał Mirosław
2012-02-11 0:17 ` Ben Greear
2012-02-08 19:54 ` [PATCH v2 03/10] e1000e: " greearb
2012-02-10 22:46 ` Michał Mirosław
2012-02-10 22:57 ` Ben Greear
2012-02-10 23:09 ` Michał Mirosław
2012-02-11 0:06 ` Ben Greear
2012-02-08 19:54 ` [PATCH v2 04/10] net: Add framework to allow sending packets with customized CRC greearb
2012-02-08 19:54 ` [PATCH v2 05/10] e100: Support sending custom Ethernet CRC greearb
2012-02-08 19:54 ` [PATCH v2 06/10] e1000e: " greearb
2012-02-08 19:54 ` [PATCH v2 07/10] net: Support RX-ALL feature flag greearb
2012-02-08 19:54 ` [PATCH v2 08/10] e1000e: Support RXALL " greearb
2012-02-08 19:54 ` [PATCH v2 09/10] e100: " greearb
2012-02-08 19:54 ` [PATCH v2 10/10] e1000: Support sending custom Ethernet CRC greearb
2012-02-10 4:31 ` [PATCH v2 00/10] Low-level Ethernet debugging features Jeff Kirsher
2012-02-10 5:42 ` Ben Greear
2012-02-10 5:52 ` Jeff Kirsher
2012-02-10 13:25 ` Eric Dumazet
2012-02-10 13:45 ` David Laight
2012-02-10 13:51 ` Eric Dumazet [this message]
2012-02-10 14:09 ` Eric Dumazet
2012-02-10 17:18 ` Ben Greear
2012-02-10 20:43 ` David Miller
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