Re: [PATCH] filter: add SKF_AD_NLATTR_NEST to look for nested attributes

[David Miller <davem@davemloft.net>]

From: Patrick McHardy <kaber@trash.net>
Date: Tue, 18 Nov 2008 11:49:18 +0100

> Pablo Neira Ayuso wrote:
> > SKF_AD_NLATTR allows us to find the first matching attribute in a
> > stream of netlink attributes from one offset to the end of the
> > netlink message. This is not suitable to look for a specific
> > matching inside a set of nested attributes.
> > For example, in ctnetlink messages, if we look for the CTA_V6_SRC
> > attribute in a message that talks about an IPv4 connection,
> > SKF_AD_NLATTR returns the offset of CTA_STATUS which has the same
> > value of CTA_V6_SRC but outside the nest. To differenciate
> > CTA_STATUS and CTA_V6_SRC, we would have to make assumptions on the
> > size of the attribute and the usual offset, resulting in horrible
> > BSF code.
> > This patch adds SKF_AD_NLATTR_NEST, which is a variant of
> > SKF_AD_NLATTR, that looks for an attribute inside the limits of
> > a nested attributes, but not further.
> > This patch validates that we have enough room to look for the
> > nested attributes - based on a suggestion from Patrick McHardy.
> 
> Looks good, thanks Pablo.
> 
> Acked-by: Patrick McHardy <kaber@trash.net>

Applied, thanks everyone.