Setup iptables for RedSocks in OpenWRT

redsocks.conf

base {
        // debug: connection progress & client list on SIGUSR1
        log_debug = on;

        // info: start and end of client session
        log_info = on;

        /* possible `log' values are:
         *   stderr
         *   file:/path/to/file
         *   syslog:FACILITY  facility is any of "daemon", "local0"..."local7"
         */
        log = stderr;

        // detach from console
        daemon = off;

        /* Change uid, gid and root directory, these options require root
         * privilegies on startup.
         * Note, your chroot may requre /etc/localtime if you write log to syslog.
         * Log is opened before chroot & uid changing.
         */
        // user = nobody;
        // group = nobody;
        // chroot = "/var/chroot";

        /* possible `redirector' values are:
         *   iptables   - for Linux
         *   ipf        - for FreeBSD
         *   pf         - for OpenBSD
         *   generic    - some generic redirector that MAY work
         */
        redirector = iptables;
}

redsocks {
        /* `local_ip' defaults to 127.0.0.1 for security reasons,
         * use 0.0.0.0 if you want to listen on every interface.
         * `local_*' are used as port to redirect to.
         */
        local_ip = 0.0.0.0;
        local_port = 12345;

        // `ip' and `port' are IP and tcp-port of proxy-server
        ip = 127.0.0.1;
        port = 1080;


        // known types: socks4, socks5, http-connect, http-relay
        type = socks5;

        // login = "foobar";
        // password = "baz";
}

redudp {                                                         
        // `local_ip' should not be 0.0.0.0 as it's also used for outgoing
        // packets that are sent as replies - and it should be fixed      
        // if we want NAT to work properly.                               
        local_ip = 127.0.0.1;                                             
        local_port = 10053;                                               
                                                                          
        // `ip' and `port' of socks5 proxy server.                        
        ip = 127.0.0.1;                                                   
        port = 1080;                                                      
        //login = username;                                               
        //password = pazzw0rd;                                            
                                                                          
        // kernel does not give us this information, so we have to duplicate it
        // in both iptables rules and configuration file.  By the way, you can 
        // set `local_ip' to 127.45.67.89 if you need more than 65535 ports to 
        // forward ;-)                                                         
        // This limitation may be relaxed in future versions using contrack-tools.
        dest_ip = 8.8.8.8;                                                        
        dest_port = 53;                                                           
                                                                                  
        udp_timeout = 30;                                                         
        udp_timeout_stream = 180;                                                 
}                                                                                 
                                                                                  
// you can add more `redsocks' and `redudp' sections if you need.       

run.sh

# at terminal 1
ssh -D1080 username@server -p443

# at terminal 2
./redsocks -c redsocks.conf
# no log texts appear after running redsocks!!

# at terminal 3
. setup-iptables.sh
# all runs fine

# at terminal 4: minicom tty via serial port
# a bunch of LOGs from iptables appear

setup-iptables.sh

# Create new chain                                                                                                                                           
iptables -t nat -X REDSOCKS                                                                                                                                  
iptables -t nat -N REDSOCKS                                                                                                                                  
                                                                                                                                                             
# Ignore LANs and some other reserved addresses.                                                                                                             
iptables -t nat -A REDSOCKS -d 0.0.0.0/8 -j RETURN                                                                                                           
iptables -t nat -A REDSOCKS -d 10.0.0.0/8 -j RETURN                                                                                                          
iptables -t nat -A REDSOCKS -d 10.10.1.0/22 -j RETURN                                                                                                        
iptables -t nat -A REDSOCKS -d 127.0.0.0/8 -j RETURN                                                                                                         
iptables -t nat -A REDSOCKS -d 169.254.0.0/16 -j RETURN                                                                                                      
iptables -t nat -A REDSOCKS -d 172.16.0.0/12 -j RETURN                                                                                                       
iptables -t nat -A REDSOCKS -d 192.168.0.0/16 -j RETURN                                                                                                      
iptables -t nat -A REDSOCKS -d 224.0.0.0/4 -j RETURN                                                                                                         
iptables -t nat -A REDSOCKS -d 240.0.0.0/4 -j RETURN                                                                                                         
#iptables -t nat -A REDSOCKS -d 122.248.x.x/31 -j RETURN                                                                                                  
                                                                                                                                                             
iptables -t nat -A REDSOCKS -j LOG -p tcp --syn --log-level info --log-prefix "rs "                                                                          
                                                                                                                                                             
# Anything else should be redirected to port 12345                                                                                                           
#iptables -t nat -A REDSOCKS -p tcp -j REDIRECT --to-ports 12345                                                                                             
iptables -t nat -A REDSOCKS -p tcp -j DNAT --to-destination 127.0.0.1:12345                                                                                  
                                                                                                                                                             
iptables -t nat -A REDSOCKS -j LOG -p tcp --syn --log-level info --log-prefix "err "                                                                         
                                                                                                                                                             
# Any tcp connection made by `darkk' should be redirected.                                                                                                   
iptables -t nat -I OUTPUT 1 -p tcp -j REDSOCKS                                                                                                               
iptables -t nat -I PREROUTING 1 -p tcp -s 192.168.1.0/22 -j REDSOCKS 

I get a dns leaking problem with this iptables configuration, I have an ssh account from singapore that I use for an ssh tunnel but after I check by going to https://dnsleaktest.com/ My DNS is still the DNS of my own country, it should come from singapore, the same country of my ssh tunnel, how can I fix that? I'm also running openwrt.

dns is udp and these iptables rules are explicitly for tcp. you need to provide for -p udp also for the udp queries including dns to be tunneled.