From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
To: Chris Wright <chrisw@osdl.org>
Cc: linux-kernel@vger.kernel.org, coreteam@netfilter.org
Subject: Re: why is sk->skb->sk_socket->file NULL on incoming packets?
Date: Fri, 10 Sep 2004 02:36:24 +0100 [thread overview]
Message-ID: <20040910013624.GG11160@lkcl.net> (raw)
In-Reply-To: <20040909182053.P1973@build.pdx.osdl.net>
On Thu, Sep 09, 2004 at 06:20:54PM -0700, Chris Wright wrote:
> * Luke Kenneth Casson Leighton (lkcl@lkcl.net) wrote:
> > hi, simple question - if a userspace ip_queue program (fireflier)
> > can determine the pid of an incoming packet, why can't ipt_owner.c
> > do the same?
> >
> > how do i force, even by using a userspace thing which asks the
> > packet to be "re-examined", the skb->sk->sk_socket->file to be
> > set?
>
> I assume the netfilter hook you come in on is NF_IP_LOCAL_IN? This is
> at ip level. The sock (sk) is protocol specific, and hasn't been
> looked up yet. Look at the protocols' input handlers (i.e. udp_rcv or
> tcp_v4_rcv), they do this lookup (i.e. udp_v4_lookup or __tcp_v4_lookup).
> The sk_filter() point is probably the first time you have an association
> between the skb (inbound) and the sock it's going to be queued to.
> LSM modules use security_sock_rcv_skb at this point.
oooo *wide-eyed*. thanks
prev parent reply other threads:[~2004-09-10 1:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-10 0:45 why is sk->skb->sk_socket->file NULL on incoming packets? Luke Kenneth Casson Leighton
2004-09-10 1:20 ` Chris Wright
2004-09-10 1:36 ` Luke Kenneth Casson Leighton [this message]
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