From: Casey Schaufler <casey@schaufler-ca.com>
To: Tilman Baumann <tilman.baumann@collax.com>
Cc: Linux-Kernel <linux-kernel@vger.kernel.org>,
linux-security-module@vger.kernel.org
Subject: Re: SMACK netfilter smacklabel socket match
Date: Thu, 25 Sep 2008 20:43:01 -0700 [thread overview]
Message-ID: <48DC5A45.8020801@schaufler-ca.com> (raw)
In-Reply-To: <48DBC9A1.20900@collax.com>
Tilman Baumann wrote:
> Hi all,
>
> i made some SMACK related patches. I hope this list is the right place
> to post them.
Here and, probably more importantly
linux-security-module@vger.kernel.org as that's
my primary hang out.
> The intention behind this patch is that i needed a way to (firewall)
> match for packets originating from specific processes.
> The existing owner match did not work well enough, especially since
> the cmd-owner part is removed.
> Then i thought about a way to tag processes and somehow match this tag
> in the firewall.
> I recalled that SELinux can do this (SECMARK) but SELinux would have
> been way to complex for what i want. But the idea was born, i just
> needed something more simple.
>
> SMACK seemed to be the right way. So i made a little primitive
> netfilter match to match against the security context of sockets.
> SMACK does CIPSO labels, but this was not what i wanted, i wanted to
> label the socket not the packet (on the wire).
> This of course only works for packets with a local socket, but this
> was my intention anyway.
>
> This way i can label a process and all it's sockets carry the same
> label which i then can use to match against in the firewall.
>
Hmm. It looks as if your code will do what you're asking it to do.
Are you going to be happy with the access restrictions that will be
imposed by Smack?
> The code is pretty much based on cargo cult coding from other
> netfilter matches, especially the owner match (which turned out to be
> a bad reference since it is crapped with tons of compat interfaces).
>
> I have no kernel coding experience whatsoever and little C coding
> history. So i would really like you guys to look over it a bit.
>
> Originally i intended to put this mask in the xtables_match structure.
> .hooks = (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_LOCAL_IN)
> But it turned out that i then could not longer put the rule in a chain
> which is called by the OUTPUT chain but only in OUTPUT directly.
> I did not investigate much more since i did not really understand this
> part. Allowing the user to add this match wherever he wants to does
> not hurt, if there is no local socket there is no matching.
> But maybe this is something that should be changed.
>
> About the Files:
> SMACK-netfilter-socket-label-match.patch
> is a git patch for the current kernel.
>
> iptables-smacklabel.patch
> contains the iptables userspace part (applies to iptables-1.4.1.1)
>
>
> Regards
> Tilman Baumann
next prev parent reply other threads:[~2008-09-26 3:43 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-25 17:25 SMACK netfilter smacklabel socket match Tilman Baumann
2008-09-25 18:26 ` Paul Moore
2008-09-25 19:26 ` Tilman Baumann
2008-09-25 19:57 ` Paul Moore
2008-09-25 20:32 ` Tilman Baumann
2008-09-26 12:35 ` Tilman Baumann
2008-09-26 19:55 ` Paul Moore
2008-09-26 3:43 ` Casey Schaufler [this message]
2008-09-26 8:19 ` Tilman Baumann
2008-09-27 5:01 ` Casey Schaufler
2008-09-29 16:21 ` Tilman Baumann
2008-09-30 3:29 ` Casey Schaufler
2008-10-01 11:29 ` Tilman Baumann
2008-10-01 15:21 ` Casey Schaufler
2008-10-01 16:55 ` Tilman Baumann
2008-10-01 18:22 ` Casey Schaufler
2008-10-06 12:57 ` Tilman Baumann
2008-10-06 23:05 ` Ahmed S. Darwish
2008-10-07 2:42 ` Casey Schaufler
2008-10-17 16:57 ` Tilman Baumann
2008-10-17 17:53 ` Casey Schaufler
2008-10-20 12:06 ` Tilman Baumann
2008-10-20 15:01 ` Casey Schaufler
2008-10-22 3:36 ` Casey Schaufler
2008-10-30 16:06 ` Tilman Baumann
2008-10-31 3:46 ` Casey Schaufler
2008-12-11 0:03 ` Casey Schaufler
2008-12-11 10:18 ` Tilman Baumann
2008-12-11 16:29 ` Casey Schaufler
2008-10-23 11:55 ` Paul Moore
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