From mboxrd@z Thu Jan  1 00:00:00 1970
From: Patrick McHardy <kaber@trash.net>
Subject: Re: [PATCH] libnfnetlink
Date: Wed, 11 Oct 2006 12:32:59 +0200
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	<451D2B3B.7070604@trash.net> <4521185D.8040005@netfilter.org>
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Cc: Maik Hentsche <netfilter@mm-double.de>, netfilter-devel@lists.netfilter.org
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To: Pablo Neira Ayuso <pablo@netfilter.org>
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Pablo Neira Ayuso wrote:
> what do you think about the following solution?
> 
> 
>>	if (len < sizeof(struct nlmsgerr)
>>	    || len < sizeof(struct nlmsghdr))
> 
> 
> errno = EBADMSG;
> 
> 
>>[...]
>>	if (addrlen != sizeof(peer))
> 
> 
> errno = EINVAL;
> 
> 
>>		return -1;
>>
>>	if (peer.nl_pid != 0)
> 
> 
> errno = ENOMSG;

The above all seem fine.

> 
>>		return -1;
>>
>>	nlh = (struct nlmsghdr *)buf;
>>	if (nlh->nlmsg_flags & MSG_TRUNC || status > len)
> 
> 
> errno = ENOSPC;

ENOSPC is fine for MSG_TRUNC, but it is a msghdr flag, not nlmsg.
status > len implies serious recvmsg brokeness and it doesn't
really make sense to check for kernel bugs, so I'd remove it.