Problems with pf rules for intercept squid proxy
kp at FreeBSD.org
Tue Jun 28 17:37:42 UTC 2016
On 28 Jun 2016, at 15:07, C. L. Martinez wrote:
> I have some problems with my pf rules on a FreeBSD 10.3 host that
> acts as a squid intercept proxy. My actual pf rules are:
> rdr pass on $vpnif proto tcp from $int_network to any port http -> lo0
> port 5144
> rdr pass on $vpnif proto tcp from $int_network to any port https ->
> lo0 port 5145
> At first stage it seems that these rules works, but don't. Traffic is
> redirected to squid, but squid denies all connections:
> 1467111934.502 1 172.22.55.1 TCP_DENIED/403 4221 GET
> http://www.osnews.com/ - HIER_NONE/- text/html
> Using same squid.conf's file under an OpenBSD test machine, squid
> works without problems. For this reason, I don't think there is some
> problem with my squid's config. The only difference between this
> OpenBSD host and FreeBSD are the pf rules.
You may have a different squid version, or they may be patched
Your redirect rules are working, as demonstrated by the fact that squid
gets a request, and replies to it.
Note that pf does not change your HTTP payload, it only affects TCP. In
other words: if Squid sees the connection (and it does) it’s a Squid
Also note that you’re redirecting on FreeBSD, but using divert-to on
This may be triggering different behaviour from Squid. The man page says
that with divert-to:
The packets will not be modified, so getsockname(2) on the socket will
the original destination address of the packet.
That might be affecting an ACL in Squid.
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