#!/bin/bash
# if you do not have access to run the script, run "chmod 755 throttling"
# to run enter in terminal "./throttling [speed]"
# full (no throttling)
# fast (300Kbit)
# medium (100Kbit)
# slow (10Kbit)
# wwdc (1Kbit)
# off (blocks connection)

# configuration
host1="yourdomain.com"
host2="localhost:3000"

# usage
if [ "$*" == "" ]; then
  echo "usage: $0 [full|fast|medium|slow|wwdc|off]"
  exit
fi

# remove any previous firewall rules
sudo ipfw list 100 > /dev/null 2>&1
if [ $? -eq 0 ]; then
  sudo ipfw delete 100 > /dev/null 2>&1
fi
sudo ipfw list 110 > /dev/null 2>&1
if [ $? -eq 0 ]; then
  sudo ipfw delete 110 > /dev/null 2>&1
fi
sudo ipfw list 200 > /dev/null 2>&1
if [ $? -eq 0 ]; then
  sudo ipfw delete 200 > /dev/null 2>&1
fi
sudo ipfw list 210 > /dev/null 2>&1
if [ $? -eq 0 ]; then
  sudo ipfw delete 210 > /dev/null 2>&1
fi

# process the command line option
if [ "$1" == "full" ]; then
  echo "full speed"
elif [ "$1" == "off" ]; then
  # add rules to deny any connections to configured host
  if [ -n "$host1" ]; then
    sudo ipfw add 100 deny tcp from $host1 to me
    sudo ipfw add 110 deny tcp from me to $host1
  fi
  if [ -n "$host2" ]; then
    sudo ipfw add 200 deny tcp from $host2 to me
    sudo ipfw add 210 deny tcp from me to $host2
  fi
else
  # create a pipe with limited bandwidth
  bandwidth="100Kbit"
  if [ "$1" == "fast" ]; then
    bandwidth="300Kbit"
  elif [ "$1" == "slow" ]; then
    bandwidth="10Kbit"
  elif [ "$1" == "wwdc" ]; then
    bandwidth="1Kbit"
  fi
  sudo ipfw pipe 1 config bw $bandwidth

  # add rules to use bandwidth limited pipe
  if [ -n "$host1" ]; then
    sudo ipfw add 100 pipe 1 tcp from $host1 to me
    sudo ipfw add 110 pipe 1 tcp from me to $host1
  fi
  if [ -n "$host2" ]; then
    sudo ipfw add 200 pipe 1 tcp from $host2 to me
    sudo ipfw add 210 pipe 1 tcp from me to $host2
  fi
fi

sudo ipfw list