[Internet]
            |
            |
         re1|
       +----=----+re2     (10.0.8.0/30)
       |   FW    |=-----------+
       +----=----+            |fxp0
         re0|             +---=---+
            |             | proxy |
            |             +---=---+
            |                 |xl0
           |||----------------+
           /|\        (10.0.7.0/24)
          [LAN]


Is it possible to configure the indicated setup above for
transparent/intercepting proxy using OpenBSD 5.6 router/firewall and
OpenBSD 5.4 proxy with Squid 3.3.8?

LAN clients have the FW as the default gateway. I planned on
intercepting WWW traffic at the firewall and redirecting to the proxy
out re2 (over the 10.0.8/0/30 net). The proxy has an intercept
listener on fxp0:

 http_port 10.0.8.2:3129 intercept

I see from Squid documentation [1] that this should be done with
divert-to and divert-reply in PF.

Is this configuration only possible if Squid runs on the same host as
the PF firewall because of a divert socket having to point locally?
With the following rule active in PF, no traffic is seen on re2 at FW.

 @51 pass in log quick inet proto tcp from 10.0.7.32 to any port = 80
flags S/SA divert-to 10.0.8.2 port 3129

The following log is seen when attempting connection from client
10.0.1.32 to WWW:

 Jul 14 16:35:18.081709 rule 51/(match) pass in on vlan103:
10.0.7.32.63958 > 209.68.27.16.80: S 1842850855:1842850855(0) win
65535 <mss 1460,nop,wscale 5,nop,nop,timestamp 796985221 0,[|tcp]>
(DF)

Is there any way to successfully configure this or similar sort of
design with interception in Squid so that the proxy can reside on a
different host than the firewall?

[1] http://wiki.squid-cache.org/ConfigExamples/Intercept/OpenBsdPf

-- 
Darren Spruell
phatbuck...@gmail.com

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