From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: Willem de Bruijn <willemb@google.com>
Cc: Network Development <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Daniel Borkmann <dborkman@redhat.com>,
David Miller <davem@davemloft.net>,
mostrows@earthlink.net
Subject: Re: [PATCH] packet: Allow packets with only a header (but no payload)
Date: Tue, 21 Jul 2015 18:38:12 +0200 [thread overview]
Message-ID: <CAFBinCB4xOBzxwkEQYrpi1q7Xm4_-hpj2jUE2r-fQ5f2grjZ=Q@mail.gmail.com> (raw)
In-Reply-To: <CA+FuTScr0o0ZmwWxVP4FZoQosRRiQG6+MDvCahMCWmjLkg+33g@mail.gmail.com>
Hi Willem,
On Tue, Jul 21, 2015 at 6:28 PM, Willem de Bruijn <willemb@google.com> wrote:
> Interesting. 9c7077622dd9 only extended the check from tpacket_snd to
> packet_snd to make the two paths equivalent. The existing check had the
> ominous statement
>
> /* net device doesn't like empty head */
OK, I guess it's best to find out what the purpose of this comment is.
> so allowing a header-only packet while correct in your case may not be
> safe in some edge cases (specific device drivers?).
I'm wondering how a good fix would look like (I can think of a few
things, like renaming hard_header_len to something min_packet_size)?
I am open for suggestions since I have zero knowledge about the inner
workings of the packet framework.
> This was also discussed previously
>
> http://www.spinics.net/lists/netdev/msg309677.html
>
> In any case, I don't think that reverting the patch and restoring the old
> inconsistent state is a fix.
I totally agree with you that it's a bad fix if this means that we
could break other drivers.
My primary goal was to fix PPPoE connections - I guess I should have
simply added "RFC" to the subject.
Regards,
Martin
next prev parent reply other threads:[~2015-07-21 16:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-21 16:14 [PATCH] packet: Allow packets with only a header (but no payload) Martin Blumenstingl
2015-07-21 16:28 ` Willem de Bruijn
2015-07-21 16:38 ` Martin Blumenstingl [this message]
2015-07-21 16:51 ` Willem de Bruijn
2015-07-27 22:35 ` Martin Blumenstingl
2015-07-29 6:05 ` Willem de Bruijn
2015-07-30 22:15 ` Martin Blumenstingl
2015-11-07 13:11 ` Felix Fietkau
2015-11-09 17:53 ` Willem de Bruijn
2015-11-09 19:02 ` Felix Fietkau
2015-11-21 0:50 ` Martin Blumenstingl
2015-11-21 21:32 ` Sergei Shtylyov
2015-11-22 16:46 ` [PATCH v3] " Martin Blumenstingl
2015-11-30 3:18 ` David Miller
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