How to get internet connectivity on an open wi-fi access point that requires a credit card without actually paying:

Prerequisites

• OpenWRT router
  • public ip, not necessarily static
• account on dns.he.net
• OS X laptop

Iodine on OpenWRT and installation on a OS X

On the OpenWRT:

• opkg install iodined
• update /etc/init.d/iodined to:

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#!/bin/sh /etc/rc.common
# Copyright (C) 2006-2011 OpenWrt.org

START=50

start_instance () {
local section="$1"
config_get address  "$section" 'address'
config_get password "$section" 'password'
config_get tunnelip "$section" 'tunnelip'
config_get tld      "$section" 'tld'

service_start /usr/sbin/iodined -l "$address" -c -s -P "$password" $tunnelip "$tld" &
sleep 1
ifconfig dns0 $tunnelip netmask 255.255.255.0
}

start() {
config_load 'iodined'
config_foreach start_instance 'iodined'
}

stop() {
service_stop /usr/sbin/iodined
}

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• so that it starts automatically

/etc/init.d/iodined enable

• edit /etc/config/iodined (because there' s a bug on openwrt)
  • change address to 192.168.14.1

config iodined
 option address ''
 option password ''
 option tunnelip '192.168.14.1'
 option tld ''

• Make sure the openwrt router has a static ip address (he.net provides dyndns updates)
• Make a dns zone: a.server.com ns -> openwrt.server.com
  • openwrt.server.com has a dyndns update
• port forward 53 (tcp and udp) from first router to second router (or just open 53 on the openwrt)

osx client

• http://tuntaposx.sourceforge.net/ (tuntap)
• script:

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#!/bin/bash

# are we root?
if ! [ $UID == 0 ] ; then
  echo "IODINE SETUP: use 'sudo $0'";
  exit 0;
fi;

#$1 says whether we use clearcode or stoynov.com
if [ -z $1 ] ; then
  echo 'IODINE SETUP: first param must be 1(i.clearcode.org) or 2(i.stoynov.com)';
  exit 0;
fi;

if [ $1 == 1 ] ; then
  endpoint_domain='i.clearcode.org'
  endpoint_net='192.168.14.0/24'
  endpoint_gw='192.168.14.1'
fi;

if [ $1 == 2 ] ; then
  endpoint_domain='j.stoynov.com'
  endpoint_net='192.168.15.0/24'
  endpoint_gw='192.168.15.1'
fi;

# get the first dns from resolv.conf and use it.
abused_nameserver=`cat /etc/resolv.conf | grep nameserver | head -1 | awk '{print $2}'`
abused_nameserver=8.8.4.4
echo ">>>>>>>>>>>>>>>>>>>USING DNS: $abused_nameserver"

# kill iodine if any and remove old routes
killall iodine
route delete 8.8.8.8 > /dev/null
route delete 8.8.4.4 > /dev/null

# get the default gateway for iodine
default_gateway=`netstat -rn | grep default | awk '{print $2}'`

#when I die, restore the default gateway, use trap to get Ctrl+C
function disconnect() {
  # kill the process with id coming as a parameter
  kill -9 $1;
  route add default $default_gateway;
}
#disconnect and exit
function cleanup() {
  disconnect $(pgrep iodine);
  exit 0;
}
trap "cleanup" SIGINT

#dns query types
dns_query_types="TXT CNAME NULL"

function connect() {
  # start iodine (possible dns types are CNAME, TXT, NULL), -F puts a pid file with the processId inside
  iodine_output=$(./iodine -T CNAME -r -P "peshev sucks" -F /var/run/iodine.pid $abused_nameserver $endpoint_domain 2>&1 | tee /dev/tty)

  #remote_net from iodine_output
  remote_net=$(echo $iodine_output | grep -o "Adding route [0-9\.]*/[0-9]\{1,2\} to [0-9\.]*" | awk '{print $3}')  

  #remote_net is something like 192.168.15.2/27 and should be 192.168.15.0/27
  remote_net=$(./ipcalc -nb $remote_net | grep Network | awk '{ print $2}')

  #tunX_ip (tunX_ip) from iodine_output
  tunX_ip=$(echo $iodine_output | grep -o "Adding route [0-9\.]*/[0-9]\{1,2\} to [0-9\.]*" | awk '{print $5}')

  #remote_gateway (gateway on iodine) from iodine_output
  remote_gateway=$(echo $iodine_output | grep -o "Server tunnel IP is [0-9\.]*" | awk '{print $5}')

  # route to nameserver to be abused
  route add -host $abused_nameserver $default_gateway
  # route to remote network via tunX_ip (necessary because my mac sucks)
  route add -net $remote_net $tunX_ip
  # change default gateway from system default to iodine 
  route delete default
  route add default $remote_gateway

  # time to download 100kb file in seconds (1.34). We remove the dot for easy comparison (1.34 -> 134)
  echo TESTING SPEED;
  t=$( { time -p curl -s ftp://speedtest:speedtest@ftp.otenet.gr/test100k.db; } 2>&1 )
  seconds=$(echo $t | awk '{ print $2;}' | tr -d . );
  echo SECONDS: $seconds;
}  
connect;

echo 'READY...READY...READY...READY...READY...'

while true; do sleep 10000; done;

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•  add ipcalc because the script needs it: ipcalc

Conclusion

Some testing found out speeds like 7-15 kb/s, sometimes less on 8.8.8.8 and 8.8.4.4. With local DNS servers the speeds are like 100kb/s. More testing is necessary.