[Qemu-devel] Re: [PATCH] tun: orphan an skb on tx

[Jan Kiszka]

Eric Dumazet wrote:
> Le mardi 13 avril 2010 à 17:36 +0200, Jan Kiszka a écrit :
>> Michael S. Tsirkin wrote:
>>> The following situation was observed in the field:
>>> tap1 sends packets, tap2 does not consume them, as a result
>>> tap1 can not be closed.
>> And before that, tap1 may not be able to send further packets to anyone
>> else on the bridge as its TX resources were blocked by tap2 - that's
>> what we saw in the field.
>>
> 
> After the patch, tap1 is able to flood tap2, and tap3/tap4 not able to
> send one single frame. Is it OK ?

I think if that's a real issue, you have to apply traffic shaping to the
untrusted nodes. The existing flow-control scheme was fragile anyway as
you had to translate packet lengths on TX side to packet counts on RX.

Jan

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