From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from jazzdrum.ncsc.mil (zombie.ncsc.mil [144.51.88.131]) by tarius.tycho.ncsc.mil (8.13.1/8.13.1) with ESMTP id k9DNO7ck019696 for ; Fri, 13 Oct 2006 19:24:07 -0400 Received: from tcsfw4.tcs-sec.com (jazzdrum.ncsc.mil [144.51.5.7]) by jazzdrum.ncsc.mil (8.12.10/8.12.10) with ESMTP id k9DNMmo6014270 for ; Fri, 13 Oct 2006 23:22:48 GMT Message-ID: <45301FFA.3080805@trustedcs.com> Date: Fri, 13 Oct 2006 18:23:38 -0500 From: Venkat Yekkirala MIME-Version: 1.0 To: selinux@tycho.nsa.gov CC: redhat-lspp@redhat.com Subject: Re: DOCUMENTATION OF SECID RECONCILIATION AND FLOW CONTROL FOR POLICY WRITERS References: <452A3F8C.5080401@trustedcs.com> <452AA26C.7050901@trustedcs.com> In-Reply-To: <452AA26C.7050901@trustedcs.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov Fixed a bug in the doc to be in line with the current proposed implementation. Venkat Yekkirala wrote: > Venkat Yekkirala wrote: >> DOCUMENTATION OF SECID RECONCILIATION AND FLOW CONTROL FOR POLICY WRITERS: >> >> ON INBOUND: >> >> 1. PACKETS ENTERING SYSTEM FROM A NON-LOOPBACK DEVICE: >> >> Can a packet "carrying" external domain label x_t "flow_in" thru the >> security point with the peer domain label p_d_t? >> >> NOTE: >> a. x_t defaults to unlabeled_t, if no external label. >> b. p_d_t defaults to network_t in the absence of any applicable >> [conn]secmark rules for the packet. If there are multiple >> secmark rules applicable to a packet, the context on the LAST >> rule will apply. >> >> NO: Drop packet. >> YES: If no external label, let packet "carry" p_d_t. s/p_d_t/p_d_t if it didn't default to network_t/ >> >> 2. INPUT ONLY: Can a socket "recv" a packet from domain p_d_t? >> >> NO: Drop packet. >> YES: If setting up a tcp connection, set peer context to p_d_t. >> >> ON OUTBOUND: >> >> 1. Let packet "carry" the originating socket domain label. >> >> 2. IPSEC Handling: >> >> LABELED IPSEC: If packet "polmatch"es to an otherwise applicable and >> labeled SPD entry, choose a Security Association (SA) with the SAME context >> as the domain label being carried by packet. >> NOTE: If no such SA present, call into IKE with context on packet. >> >> NON-LABELED (PLAIN/TRADITIONAL) IPSEC: If there's an applicable SPD entry >> that does NOT have an explicit context associated with it, an applicable SA >> that does NOT have an explicit context associated with it is chosen. >> NOTE: If no such SA present, call into IKE, but with NO context. >> >> 3. PACKETS DESTINED FOR NON-LOOPBACK DEVICE: >> >> a. IPTABLES Processing: >> As EACH applicable iptables [CONN]SECMARK rule with domain p_d_t is >> encountered, do the following: >> >> Can a packet carrying domain label a_t "flow_out" of the security point >> with the domain label p_d_t? >> >> NO: Drop packet. >> YES: Replace the domain label a_t on the packet with the security point >> label p_d_t. >> >> b. Before a packet is let out of the system: >> >> Can a packet with domain label p_d_t "flow_out" into the network domain >> network_t? >> >> NO: Drop packet. >> YES: Let packet out. >> >> NOTE: Ideally this check should be applicable only to packets that >> didn't go thru [conn]secmark checks for outbound, but there's >> currently no way to know this due to implementation constrains. >> Hence a blanket check for ALL packets leaving the system. >> >> >> FORWARDED TRAFFIC: >> >> Forwarded Traffic will undergo the following: >> >> 1. Step 1 under ON INBOUND. >> >> 2. Steps 2 and 3 under ON OUTBOUND. > NOTE: The iptables FORWARD chain is treated as an outbound chain > for flow control purposes. That means forwarded traffic would > need to be flow-controlled/labeled when it comes into the system > using an applicable rule in the PREROUTING chain, and flow-controlled > before it leaves the system using rules either in the FORWARD chain > or the POSTROUTING chain. > > -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message.