WPAD Setup help [Solved]

aGeekhere

Last updated May 23 2016

please now refer to https://forum.pfsense.org/index.php?topic=112335.0

How to setup a WPAD for non transparent web filtering

Set all nodes to the same workgroup (may be not needed)

1. Create wpad files, either use Diagnostics: Edit file or use ssh to add the files, TIP: make a symbolic link between the files


vi /usr/local/www/wpad.dat
vi /usr/local/www/wpad.da
vi /usr/local/www/proxy.pac

The following wpad code allows all local ip addresses to go direct but makes all external connections go through the proxy (you must adjust the IP information to suit your setup)
The code for the 3 files are


function FindProxyForURL(url, host) 
{ 
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

    return "PROXY 192.168.1.1:3128";
}

If you connect to a VPN you need to go direct for the VPN instead of the proxy, Remember you need to add the correct network class for the VPN either A, B or C


function FindProxyForURL(url, host) 
{ 
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

        if (isInNet(dnsResolve(host), "1.0.0.0",  "255.0.0.0" ))
        { return "DIRECT"; }

    return "PROXY 192.168.1.1:3128";
}

2. Enable DNS Resolver (not using DNS forwarder)

3.Configure DNS Resolver
add new Host Overrides


Host: wpad
Domain: mylocaldomain.local
IP Address: 192.168.1.1
Description: WPAD Autoconfigure Host

save

4. Configure DHCP server

Services: DHCP server
Additional BOOTP/DHCP Options

number: 252 type: string value: "http://192.168.1.1/wpad.dat"
number: 252 type: string value: "http://192.168.1.1/wpad.da"
number: 252 type: string value: "http://192.168.1.1/proxy.pac"

5. run some test
a. can the file be download at the following link?

http://wpad.mylocaldomain.local/wpad.dat

If not try this address

http://pfsense.mylocaldomain.local/wpad.dat

b. run a nslookup in cmd (windows)

nslookup wpad.mylocaldomain.local

or try

nslookup pfsense.mylocaldomain.local

result should be something like this


Server:  pfSense.mylocaldomain.local
Address:  192.168.1.1
Name:    wpad.mylocaldomain.local
Address:  192.168.1.1

6. Configure DHCP server
Services: DHCP server
Additional BOOTP/DHCP Options


number: 252 type: string value: "http://192.168.1.1/wpad.dat"
number: 252 type: string value: "http://192.168.1.1/wpad.da"
number: 252 type: string value: "http://192.168.1.1/proxy.pac"

set pfsense Protocol to http (This is a MUST, it will not work if you do not do this)
System: Advanced: Admin Access Protocol http

7. Block lan Destination port 80 and 443 (http, https)
Firewall: Rules lan

IPv4 TCP * * * 80 - 443 * none

or add two rules

setup web browsers
For Chrome and IE make sure that autodiscovery is turned on in internet options.
Try the same for firefox, if firefox does not find the wpad add automatic proxy configuration url to the url of the wpad (like http://pfsense.mylocaldomain.local/wpad.dat)

Hope this helps some people

rule.png_thumb

chris4916

@aGeekHere:

I do not think I have set up the LAN rules correctly, as it is not working.

Could you please be more explicit, explaining what doesn't work?
e.g. can you access http://wpad.yourdomain/proxy.pac

aGeekhere

By not working I mean all http traffic is blocked and I can only access https sites.

If I disable the firewall rule then nothing is being filtered but then I can access
http://192.168.1.1/proxy.pac
and the file downloads.

I must have missed something.

In Services: DNS forwarder do I need to Enable DNS forwarder? The guide only talks about adding a new Host Override and not what the other settings should be.

If I try to Enable DNS forwarder i get an error
The following input errors were detected:
The DNS Resolver is enabled using this port. Choose a non-conflicting port, or disable DNS Resolver.

I must be missing something.

[Update]
ok it seems that when I try to enable Enable DNS forwarder and set the Listen Port to 80 the DNS Forwarder service will not start

chris4916

The way it works (supposed to work) is that your browser searches for http://wpad.your_domain/proxy.pac which will provide you with required inputs so that your browser configures itself with the right settings (meaning proxy address, port and behaviour (e.g. exceptions).
That is easy as this 8)

Then everything else depends on your own implementation:

if your web site serving http://wpad.your_domain can't be accessed on port 80, it will not work (this refers potentially to FW rules)
if this FQDN can't be resolved, it will not work (this refers to DNS settings but also to your workstation settings: it has to be configured with domain otherwise this domain can't be guessed)
if it contains wrong inputs, it will not work (refers to proxy.pac content)

troubleshooting is however quite simple:

you could e.g. test your proxy.pac by configuring your browser, manually, with this URL
you could try to resolve wpad.your_domain (hint: try also "wpad", this will ensure you also have the right "search domain"
you could try to access http://wpad.your_domain/proxy.pac (which should show you its content)

I hope this helps ;)

EDIT: there is one last (perhaps critical) point I forgot => did you try to access internet relying on your proxy, i.e. configuring your browser (hardcoded) to use your proxy?

aGeekhere

Ok, I think I am getting closer, The main issue I get now is that I get locked out of pfsense web gui and all Local addresses.

So what I have done is I have committed out the 3 files and only uncommitted the proxy.pac (which seems to be for IE, I have done this so I do not get locked out on chrome and firefox). When I test it on IE the blocking works :) even https sites :) ~~but only for my PC and not the others on the LAN??? they have the same setups???.~~ Fixed that

However then IE gets locked out of pfsense and for that matter ALL local domains.

The error message i get is:

Request denied by pfSense proxy: 403 Forbidden
 Reason:  
 Client address:  192.168.1.55 
 Client group:  default 
 Target group:  in-addr 
 URL:  http://192.168.1.1/192.168.1.22/--GET

Any Ideas?

aGeekhere

Did some updates to the first post

[Update]
Ok it seems that when I setup a manual proxy I get the same lockout issue (getting closer).
So the issue does not seem to be with the WPAD setup

Does anyone else have an issue with squid's non transparent proxy (manual proxy setup) access local addresses (like the pfsense GUI)??

chris4916

Not the ultimate way of solving the issue, what you could (should ?) do is to customize your proxy.pac file so that you do not rely on proxy when accessing local files, including pfSense GUI.

This is done adding "DIRECT" directive. Something like (copy from this link which contains interesting stuff)


function FindProxyForURL(url, host) {

// If the requested website is hosted within the internal network, send direct.
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

// DEFAULT RULE: All other traffic, use below proxies, in fail-over order.
    return "PROXY 192.168.1.1:3128";

}

Notice that proxy.pac can contains other directives. I suggest you have a look at this once it works ;)

aGeekhere

Thanks, I will have a look at that to see if it works.

aGeekhere

updated first post, do not know what to try next.

chris4916

@aGeekHere:

updated first post, do not know what to try next.

Ouch :o meaning we have to read it again and guess how it differs from initial post, then for those discovering this thread, they may find answers meaningless if initial post changed significantly.
IMHO, this is more confusing than helpful except if you managed to heavily comment what was written before and how it changed.

aGeekhere

it was more of a clean up

chris4916

Reading your first post again:

1 - you could easily maintain one single file and create symlink
2 - I'm not sure you can push multiple "DHCP option 252" values :(
3 - your proxy.pac file states:

if there is no domain extension (no FQDN but host only)
or if FQDN belongs to "local" domain (is it really your domain name ?)
OR if IP I tray to reach belongs to my LAN
then go DIRECT (without proxy)

Is it what you target?

4 - I don't understand

Can connect to the internet (local ips are inaccessible, filtering works)

???

5 - would you mind replacing "cannot connect to internet" with something clearer like the error message you receive?

chris4916

@aGeekHere:

it was more of a clean up

Sure, I did notice but if your read the whole thread again as if you were discovering it, posts after your initial post are totally meaningless isn't it? ::)

chris4916

Let's try something basic:

Using Firefox (let's focus on on browser for the time being)

using "automatic proxy detect for this network" option, it doesn't work (although error message would be more than welcome here)
using manual proxy configuration (192.168.1.1 port 3128), it works and as there is no option for local IPs, these local servers can't be reached (still I don't understand why => this would mean that proxy can access or can't resolve such URL)
using "Automatic proxy configuration URL" option: this is not clear to me whether it works or not.

I also have the feeling that there is something unclear with your DNS: I'm very confused with error/warning message about DNS forwarder and port 80 ??? ???

aGeekhere

Hi all, I have time again to try and get the wpad working.

I think I am starting to get my head around this.

This is where i am at
pfsense is using the wpad files but with issues.

with this wpad example the issue is local address are blocked

function FindProxyForURL(url,host)
 {
 return "PROXY 192.168.1.1:3128";
 }

to solve this we use this to allow local addressed

function FindProxyForURL(url, host) {
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

    return "PROXY 192.168.1.1:3128";
}

With this

sites in the squardguard blacklist are blocked with the squidguard error message (this is good)
navigating to normal sites have major issue, some only half load, some do not load at all.

Getting very close to solving this, i think it could be the wpad code.

Anyone have any ideas?

chris4916

Like with my previous reply, I think it deserves clearer message: what does "with this wpad example the issue is local address are blocked" mean?
Is it "blocked" because not found, time-out, not authorized by proxy?

What you are describing shows that your WPAD set-up is working as expected:

without any specific rule, everything goes thorough proxy, including internal targets but internal servers can't be reached via proxy (this I don't know yet why)
if you set-up proxy.pac to do direct for internal servers, you can reach it.

Thus issue is definitely not with WPAD, IMHO 8)

aGeekhere

Hi chris4916 I will try to be more clear with the current issue I have.

The wpad (goal is to allow local sites to bypass the proxy but make all external sites to go through the proxy)

function FindProxyForURL(url, host) {
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

    return "PROXY 192.168.1.1:3128";
}

Current status
pfsense is now passing the wpad onto the browsers (chrome and ie for now through the DNS forwarder).

http://www.lagado.com/proxy-test shows that the browsers are connected through a proxy (good)

sites in the squidguard blocklist are being blocked for both http and https connections (good)

Current issue
Normal websites (sites which are not blocked form squidguard) are not loading correctly (Images are missing, layout is not fully loaded and some sites do not load at all).

"with this wpad example the issue is local address are blocked" mean?
I was just outlining that if you use that example wpad from https://doc.pfsense.org/index.php/WPAD_Autoconfigure_for_Squid that local addresses are blocked and by blocked i mean I get a proxy error (can't remember what the error was).

What you are describing shows that your WPAD set-up is working as expected
That is correct the WPAD is now working (however now have another issue with webpages not loading correctly)

if you set-up proxy.pac to do direct for internal servers, you can reach it.
I can reach them now by using the following wpad

function FindProxyForURL(url, host) {
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

    return "PROXY 192.168.1.1:3128";
}

Let me know if I need to expand on anything

chris4916

That's clearer (I hope :))

So your current issue has nothing to do with WPAD but with proxy (Squid) that is not loading pages as expected (or Squidguard blocking some parts of these pages)
Did you look at squid log content already?

Keep in mind that quite often web pages as you see it through your browser are built from different sources.
I would suggest that you perform some tests without any Squidguard rules or even Squid ACL, just to ensure that from HTTP standpoint, everything is OK btween your browser and external web servers, then introduce Squid ACL if needed and Squidguard rules so that you can, perhaps, determine, what's wrong here.

aGeekhere

I have updated the first post, I now use the strikethrough to show old settings. Very strange issue this is now, squidguard is not showing any blocked items for non blocked sites and even if I turn it off or allow all to squidguard I get the same issue (sites not loading correctly, missing content, not loading at all AND very very slow webpage loading times).

Stuck atm (I wounder if it is squid3 that is the issue);

Any ideas on what I should try next?

chris4916

@aGeekHere:

I have updated the first post, I now use the strikethrough to show old settings.

From personal viewpoint, this is not something I use to do because it makes next posts most of the time out of context.

Very strange issue this is now, squidguard is not showing any blocked items for non blocked sites and even if I turn it off or allow all to squidguard I get the same issue (sites not loading correctly, missing content, not loading at all AND very very slow webpage loading times).

Stuck atm (I wounder if it is squid3 that is the issue);

I'm not using Squid on pfSense but reading various threads here and there, it looks like there is a significant amount of problems with Squid on pfSense 2.x
At least, you have clarified that Squidguard is not the issue here, neither WPAD ;)
Now you could perhaps focus on Squid logs…