Productivity improving firewall script for MacOSX / BSD

surf-control.sh

#!/bin/bash

##
## Requires pwgen, wc, sed, host, ipfw, sudo
##

HOSTS="last.fm www.discogs.com www.facebook.com facebook.com 
 macrumors.com dealextreme.com www.dealextreme.com db.no www.db.no
 vg.no www.vg.no aftenposten.no www.aftenposten.no amazon.com 
 www.amazon.com"

PASSWORD=$(pwgen 10 1)
REVERSE=$(echo $PASSWORD |rev)
IPFWRULE=1337

if [ "$1" == "disable" ]; then
  echo -n "Type $REVERSE backwards: " 
  read i

  if [ "$i" == $PASSWORD ]; then
    echo "Authenticating as root"
    sudo ipfw del $IPFWRULE
  else
    echo "Wrong password! No surfing for you!"
  fi
  exit 1
fi

echo "Blocking hosts.  Use \"$0 disable\" to unblock."

NUMHOSTS=$(echo $HOSTS | wc -w)
COUNT=0

echo "Authenticating as root"
for HOST in $HOSTS; do
  let COUNT=$COUNT+1
  IPS+=$(host $HOST | grep "has address" | cut -d\  -f4)" "
  NUM=$(echo $IPS | wc -w)
  if [ $NUM -gt 10 ] || [ $NUMHOSTS -eq $COUNT ]; then
    SITES=$(echo $IPS | sed 's/ /,/g')
    sudo ipfw add $IPFWRULE deny all from any to $SITES 80,443
    IPS=""
  fi
done