[squid-users] Problems with ACL's using squid as intercept proxy

[C. L. Martinez]

Hi all,

 I am trying to configure a second squid proxy as an intercept proxy but this time under FreeBSD instead of OpenBSD. Doing my first tests I have a problem with acl's that I don't understand. To isolate the problem, I have started with a simple squid.conf file:

#
# Recommended minimum configuration:
#

# Example rule allowing access from your local networks.
# Adapt to list your (internal) IP networks from where browsing
# should be allowed
acl localnet src 10.0.0.0/8	# RFC1918 possible internal network
acl localnet src 172.16.0.0/12	# RFC1918 possible internal network
acl localnet src 192.168.0.0/16	# RFC1918 possible internal network
acl localnet src fc00::/7       # RFC 4193 local private network range
acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines

acl SSL_ports port 443
acl Safe_ports port 80		# http
acl Safe_ports port 21		# ftp
acl Safe_ports port 443		# https
acl Safe_ports port 70		# gopher
acl Safe_ports port 210		# wais
acl Safe_ports port 1025-65535	# unregistered ports
acl Safe_ports port 280		# http-mgmt
acl Safe_ports port 488		# gss-http
acl Safe_ports port 591		# filemaker
acl Safe_ports port 777		# multiling http
acl CONNECT method CONNECT

#
# Recommended minimum Access Permission configuration:
#
# Deny requests to certain unsafe ports
http_access deny !Safe_ports

# Deny CONNECT to other than secure SSL ports
http_access deny CONNECT !SSL_ports

# Only allow cachemgr access from localhost
http_access allow localhost manager
http_access deny manager

# We strongly recommend the following be uncommented to protect innocent
# web applications running on the proxy server who think the only
# one who can access services on "localhost" is a local user
#http_access deny to_localhost

#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
#

# Example rule allowing access from your local networks.
# Adapt localnet in the ACL section to list your (internal) IP networks
# from where browsing should be allowed
http_access allow localnet
http_access allow localhost

# And finally deny all other access to this proxy
http_access deny all

# Squid normally listens to port 3128
http_port 3128
http_port 127.0.0.1:5144 intercept

# Uncomment and adjust the following to add a disk cache directory.
#cache_dir ufs /var/squid/cache 100 16 256

# Leave coredumps in the first cache dir
coredump_dir /var/squid/cache

#
# Add any of your own refresh_pattern entries above these.
#
refresh_pattern ^ftp:		1440	20%	10080
refresh_pattern ^gopher:	1440	0%	1440
refresh_pattern -i (/cgi-bin/|\?) 0	0%	0
refresh_pattern .		0	20%	4320

 As you can see, I have configured only one port for intercept http requests ... I have configured new PF rules in this new FreeBSD host:

rdr pass on $vpnif proto tcp from $int_network to any port http tag intlans-to-inet -> lo0 port 5144

 .. And the result is:

1467122773.928      0 127.0.0.1 TCP_MISS/403 4357 GET http://www.osnews.com/ - HIER_NONE/- text/html
1467122773.928     35 172.22.55.1 TCP_MISS/403 4489 GET http://www.osnews.com/ - ORIGINAL_DST/127.0.0.1 text/html
1467122774.068      0 172.22.55.1 TCP_MEM_HIT/200 13096 GET http://fbsdprx.my.domain.com:3128/squid-internal-static/icons/SN.png - HIER_NONE/- image/png
1467122774.102      0 127.0.0.1 TCP_MISS/403 4314 GET http://www.osnews.com/favicon.ico - HIER_NONE/- text/html
1467122774.103      2 172.22.55.1 TCP_MISS/403 4446 GET http://www.osnews.com/favicon.ico - ORIGINAL_DST/127.0.0.1 text/html

 .. What is the problem?? Are ACL's wrong?? Why?? At first stage, I was thinking about a problem with the pf rules ... but, now, I am not sure because packets arrives to squid ...

 Any idea??

Thanks.

-- 
Greetings,
C. L. Martinez