Sharing transparently proxied Internet connection with PS3

Question

I am trying to play a Japanese karaoke game on a PS3 but the latency is just horrendous and downloading songs takes forever. One recommendation I got was to turn my laptop into a SOCKS proxy by logging in via OpenSSH to my friend's server in Japan.

[server]----(ssh tunnel)---[wlan0 < laptop > eth0]---[PS3]

So that's what I did:

ssh -ND 4711 [e-mail]

At that moment I tried reaching google.com from my laptop using Firefox (with SOCKS proxy settings) and I got redirected to google.co.jp. Great.

Then I wanted to connect my PS3 to my laptop via Ethernet.

I first assigned a static IP to eth0 with:

ip link set dev eth0 up
ip addr add 139.96.30.100/24 dev eth0

I then started a DHCP server on my laptop to give an IP to the PS3 with:

systemctl start dhcp4.service

And finally I enabled NAT with some iptables magic:

iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE

I went to "Networks Settings" and tested the connection from my PS3 and nice, it seemed to work. I launched the web browser and google.com got redirected to google.fr. How stupid, I forgot to forward the connection to the right port.

After a lot of connection forwarding through iptables that didn't work I decided to try using a transparent proxy: redsocks. http://darkk.net.ru/redsocks/

After installation I modified /etc/redsocks.conf to suit my needs:

redsocks {
    local_ip=0.0.0.0; // documentation says: "use 0.0.0.0 if you want to listen on every interface"
    local_port=31388;
    ip=127.0.0.1;
    port=4711;
}

with the rest left out as it was in https://github.com/darkk/redsocks/blob/master/redsocks.conf.example

I used the basic redsocks.rules provided in the package I installed:

*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:REDSOCKS - [0:0]

# Redirect all output through redsocks
-A OUTPUT -p tcp -j REDSOCKS

# Whitelist LANs and some other reserved addresses.
# https://en.wikipedia.org/wiki/Reserved_IP_addresses#Reserved_IPv4_addresses
-A REDSOCKS -d 0.0.0.0/8 -j RETURN
-A REDSOCKS -d 10.0.0.0/8 -j RETURN
-A REDSOCKS -d 127.0.0.0/8 -j RETURN
-A REDSOCKS -d 169.254.0.0/16 -j RETURN
-A REDSOCKS -d 172.16.0.0/12 -j RETURN
-A REDSOCKS -d 192.168.0.0/16 -j RETURN
-A REDSOCKS -d 224.0.0.0/4 -j RETURN
-A REDSOCKS -d 240.0.0.0/4 -j RETURN

# Redirect everything else to redsocks port
-A REDSOCKS -p tcp -j REDIRECT --to-ports 31338

COMMIT

That allowed me to stop using the SOCKS proxy settings on Firefox and luakit which I confirmed with the google.com turning into google.co.jp test.

I figured I still had to enable NAT so I redid:

iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE

The PS3 apparently bypassed the system-wide proxy and google.com got redirected to google.fr. I then used the redsocks.rules file as it was without masquerading. I believed that anyway I wouldn't need NAT since the redsocks server apparently listens on every interface.

I tried connecting the PS3 again and I got the following message (after the PS3 acquired an IP from my DHCP server and failed at getting an internet connection):

"An error occured during communication with the server. This is a DNS error."

That's where I am right now. I guess it might be a problem with redsocks though, since it uses a DNS server called dnstc which does this according to the documentation:

dnstc {
    // fake and really dumb DNS server that returns "truncated answer" to
    // every query via UDP, RFC-compliant resolver should repeat same query
    // via TCP in this case.
    local_ip = 127.0.0.1;
    local_port = 5300;
}

My wild guess is that my PS3 requests DNS resolution via UDP and that dnstc replies with "truncated answer" all the time. If I understand correctly, it should resend the request through TCP but apparently it produces a DNS error instead??

What should I do? Or more precisely:

• Is redsocks unnecessary? Am I just iptables-illiterate?
• Should I install a DNS server and forward the DNS requests? If so, how?

Thanks for reading that wall-of-text! Hope it doesn't suck too much for a first question...

Answer 1

You could set the PS3 to use a static DNS server. You could try OpenDNS, which has servers on 208.67.222.222 and 208.67.220.220, or try Google's public DNS server on 8.8.8.8 and 8.8.4.4.