Re: [PATCH 2/4] [NETLINK] introduce netlink_check_skb function

[Pablo Neira <pablo@eurodev.net>]

Hi Thomas,

Thomas Graf wrote:

>>They are all the same thing. They all return 16 bytes which is the size 
>>of a netlink header. If you and someone else think that those are more 
>>readable, I'm ok with it, whatever. I just stole that piece of code as 
>>is from current checkings done in xfrm and rtnetlink.
>>    
>>
>
>That's absolutely true, my point is that while reading that line
>of code it reads like while the remaining length in the socket buffer
>is still greather or equal than the total message size until the next
>message with a payload of 0, then do something. It looks confusing at
>a first glance because you're not event interested in the payload just
>now. A choice of NLMSG_ALIGN(sizeof(*nlh)) or NLMSG_LENGTH(0) clearly
>points out that you're just checking for enough room regarding the
>netlink header in order to access it safely and do the real sanity
>check against the complete message length. Engross that thought a bit
>further, NLMSG_SPACE could change at some point assuming that it is
>only used in contexts where the total message size is in question.
>
>If you think that's too much of nitpicking, then forget about it. It's
>technicaly absolutely correct at the moment.
>  
>

Looks fine you convince me. If this is finally pushed forward, let's 
replace that line. Thanks.

--
Pablo