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I am using SoftEther as a VPN and Squid for proxy.

I want to forward this VPN to proxy and then to internet.

My basic requirement is like this.

SmartPhone---->VPN--->Squid--->Internet
                        |
                        |
                        V
               internet access log

So far I have configured SofteEther VPN and it works as a normal vpn, Squid is installed in server and it works when connected as a normal proxy.

I have tried to set iptables rules to forward vpn traffic to squid( ie from port 80 to 3128[squid listening port]), but it didn't worked.

I am not a well experienced person in this area, So I request you to help me find what I am doing wrong(or please let me know if this is not possible).

VPN and Squid is configured in Amazon EC2.

Arun Xavier
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  • You need to configure Squid as a transparent proxy. If you configure it as a normal proxy, then you need to specify proxy server addresses in your clients' browsers. – Tero Kilkanen Apr 12 '17 at 12:00

2 Answers2

3

I have this set up actually, took me a while to set up too...

If you're using OpenVPN you can use my up/down script for OpenVPN/squid. You'll also need to set up BIND to go thru the VPN too:

#!/usr/bin/env bash

status="$1"
ip="$5"
configdir_squid="/etc/squid/proxyoff"
configdir_bind="/etc/named"

if [ "$status" = "up" ]; then
        echo "tcp_outgoing_address $ip" > "$configdir_squid/tcp_outgoing_address.conf"
        echo "http_access allow localnet" > "$configdir_squid/http_access.conf"
        echo "query-source address $ip;" > "$configdir_bind/query_source.conf"
else
        echo "" > "$configdir_squid/tcp_outgoing_address.conf"
        echo "http_access deny localnet" > "$configdir_squid/http_access.conf"
        echo "" > "$configdir_bind/query_source.conf"
fi

systemctl restart named squid transmission-daemon

Then create a folder, called proxyoff inside /etc/squid. Then set up the scripts in OpenVPN:

up "/opt/scripts/openvpn_tun1.sh up"
down "/opt/scripts/openvpn_tun1.sh down"

You'll need IPtables rules which control communication from squid and bind (you'll need to set up static routes for your VPN provider):

-A vyprvpn-only -o lo -j ACCEPT
-A vyprvpn-only -d 192.168.1.0/24,10.8.0.0/24 ! -o tun1 -j ACCEPT
-A vyprvpn-only ! -o tun1 -j REJECT --reject-with icmp-net-unreachable
-A OUTPUT -m owner --gid-owner transmission -j vyprvpn-only
-A OUTPUT -m owner --gid-owner squid -j vyprvpn-only
-A OUTPUT -m owner --gid-owner named -j vyprvpn-only

Add somewhere at the bottom of your http_access rules in squid, but BEFORE http_access deny all:

include /etc/squid/proxyoff/http_access.conf

Also add, after http_port or after your http_access rules:

include /etc/squid/proxyoff/tcp_outgoing_address.conf

Set your nameservers so that they reflect a DNS server on the LAN which will go through the VPN or to an internet DNS server which'll go through the DNS by the iptables rules:

dns_v4_first on
dns_nameservers 8.8.8.8 8.8.4.4

For example, I have my dns_nameservers as 3 Windows DNS servers which handle AD and then send any queries they don't know, back to BIND servers running on the same servers as the VPN.

Add a gateway failure for the localnet ACL in squid or rename the ACL and the ACL in the scripts:

deny_info ERR_GATEWAY_FAILURE localnet

Then just set up a proxy autoconfig:

function FindProxyForURL(url, host) {
    var proxy_on = "PROXY 192.168.1.20:3128; PROXY 192.168.1.21:3128";
    var proxy_off = "DIRECT";
    var network = "192.168.1.0";
    var subnet = "255.255.255.0";

    var proxy_bypass = new Array(
        "pyronexus.lan", "*.pyronexus.lan",
        "pyronexus.com", "*.pyronexus.com",
        "amazon.com", "*.amazon.com",
        "amazon.co.uk", "*.amazon.co.uk",
        "channel4.com", "*.channel4.com",
        "c4assets.com", "*.c4assets.com",
        "ipv6-test.com", "*.ipv6-test.com",
        // Banks
        "tsb.co.uk", "*.tsb.co.uk",
        "bankofscotland.co.uk", "*.bankofscotland.co.uk",
        "barclays.co.uk", "*.barclays.co.uk",
        "halifax.co.uk", "*.halifax.co.uk",
        "rbs.co.uk", "*.rbs.co.uk",
        "natwest.com", "*.natwest.com"
    );

    var blockedsites = new Array(
        "trafficstars.com", "*.trafficstars.com",
        "trafficfactory.biz", "*.trafficfactory.biz"
    );

    // Blocked websites (block them in the proxy server configuration to prevent circumvention
    for (var i = 0; i < blockedsites.length; i++) {
        if (shExpMatch(host, blockedsites[i])) {
            return "proxy 127.0.0.1";
        }
    }

    // Below here evaluates the above.
    // Bypass proxy for local web servers in the same subnet as the client.
    if (isInNet(host, network, subnet)) {
        return proxy_off;
    }

    // Bypass proxy for those listed under proxy_bypass.
    for (var i = 0; i < proxy_bypass.length; i++) {
        if (shExpMatch(host, proxy_bypass[i])) {
            return proxy_off;
        }
    }

    // Everything else not caught by the above, should be checked to see if it is HTTP, HTTPS or FTP
    // before sending to a proxy server.
    if (shExpMatch(url, "http:*") ||
        shExpMatch(url, "https:*") ||
        shExpMatch(url, "ftp:*")) {
            return proxy_on;
    }

    // Finally, send all other requests direct.
    return proxy_off;
}

Add this to /etc/named.conf under options (add forwarders to internet DNS servers but delete the root hints):

include "/etc/named/query_source.conf";

Add the VPN's IP to /etc/hosts:

209.99.22.37    uk1.vyprvpn.com

And add the route:

ip route add 209.99.22.37/32 via 192.168.1.1 dev eth0

You can see some of my other guides about proxying at https://pyronexus.com

NotoriousPyro
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1

You can read this:

https://www.williamjbowman.com/blog/2015/12/22/a-transparent-ad-blocking-vpn-via-softether-privoxy/

The author redirect all 80 port traffic to privoxy, for ad blocking, you can change his command to redirect to squid.

iptables -t nat -A PREROUTING -s YOUR.NET.ADDRESS/NETTMASK -p tcp -m multiport --dport 80 -j DNAT --to-destination 127.0.0.1:3128
Mihail Kuznesov
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