Re: [patch v1, kernel version 3.2.1] rtnetlink workaround aroundthe skb buff size issue

From: Eric Dumazet
Date: Mon Feb 06 2012 - 11:56:09 EST


Le lundi 06 fÃvrier 2012 Ã 10:15 -0500, David Miller a Ãcrit :
> From: Åtefan Gula <steweg@xxxxxxx>
> Date: Mon, 6 Feb 2012 09:53:28 +0100
>
> > If I try to request for it, it will eventually fail with a lot of
> > records even with filtering...
>
> Then the user can loop increasing the buffer size until the netlink
> request succeeds.
>
> It is not a problem.

Actually we always truncate message in netlink_recvmsg()

We could use a MSG_NOPARTIAL flag in netlink_recvmsg() so that user can
avoid the MSG_PEEK operation to fetch next message length.

(Ie not consume/copy skb if user buffer is too small to hold full
message, and only return the needed length)



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