ReconnectNetwork

#!/bin/bash

# /usr/local/bin/ReconnectNetwork
# (c) Kevin Trumbull 2010-11-29

# --------------- Notes ---------------
# This is a standalone script.  It does not interact with or depend on any other script or framework.
# It has been tested on MacOS X 10.5 and 10.6.
# It requires an appropriate LaunchD script to make it run (every 60 seconds by design)
#
# On a desktop machine, the script will not reconnect to Wifi if the wired ethernet card is plugged in, active, and has an IP.
#
# In order to make the script not run on a laptop, Airport must be disabled in the control panel.


# --------------- Variables ----------------

# Command path
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin
# File Locations
LOGFILE="/var/log/PUHSD/connectivity.log"
LOCKFILE="/var/log/PUHSD/lock/networklocation.lock"
BOOTLOG="/var/log/PUHSD/boot.log"
SLEEPLOG="/var/log/PUHSD/sleep.log"
WAKELOG="/var/log/PUHSD/wake.log"
# Model of Macintosh
MACTYPE=`sysctl -n hw.model | sed -e 's/[0-9]*,[0-9]*//'`
# Ethernet (802.3)
ETHERNETSTATUS=`ifconfig en0 | awk '/status:/{ print $NF }'`
ETHERNETIP=`networksetup -getinfo Ethernet | awk '/IP address/{ print $NF }'`
# Airport (802.11)
AIRPORTIP=`networksetup -getinfo Airport | awk '/IP address/{ print $NF }'`
AIRPORTENABLED=`networksetup -getnetworkserviceenabled Airport`
# Network Locations (Profiles)
NETWORKLOCATIONS=`scselect 2>&1 | cat | sed -ne '/[A-Z0-9]\{8\}-[A-Z0-9]\{4\}-[A-Z0-9]\{4\}-[A-Z0-9]\{4\}-[A-Z0-9]\{12\}/p' | wc -l | sed -e 's/\ //g'`
ORIGINALNETWORKLOCATION="`scselect 2>&1 | cat | sed -ne '/^\ *\*/p' | awk '{ print $NF }' | sed -e 's/[()]//g'`"
ALTERNATENETWORKLOCATION="`scselect 2>&1 | cat | sed -ne '/^\ \ /p' | awk '{ print $NF }' | sed -e 's/[()]//g' | head -n 1`"
# Temporal Settings
TIME=`date +"%Y.%m.%d-%H.%M"`
STARTTIME=`sysctl kern.boottime | grep -Eo "\ sec\ =\ [0-9]*" | awk '{print $NF }'`
SLEEPTIME=`sysctl kern.sleeptime | grep -Eio "\ sec\ =\ [0-9]*" | awk '{print $NF }'`
WAKETIME`sysctl kern.waketime | grep -Eo "\ sec\ =\ [0-9]*" | awk '{print $NF}'`
NOW=`date +%s`
# Various other settings
USER="AirportHelper"
MACHINENAME=`hostname -s | tr [:lower:] [:upper:]`

# --------------- Main Script ---------------

touch $LOGFILE
touch $BOOTLOG
touch $SLEEPLOG
touch $WAKELOG

# ----- Log Boot/Sleep/Wake Times -----
# Only one entry per Boot
if [ "`tail -1 $BOOTLOG | awk -F "\t" { print $2 }`" -ne "$STARTTIME" ]; then
    printf "$STARTTIME\t`date -r $STARTTIME`\n" >> $BOOTLOG
fi
if [ "`tail -1 $SLEEPLOG | awk -F "\t" { print $2 }`" -ne "$SLEEPTIME" ]; then
    printf "$SLEEPTIME\t`date -r $SLEEPTIME`\n" >> $SLEEPLOG
fi
if [ "`tail -1 $WAKELOG | awk -F "\t" { print $2 }`" -ne "$WAKETIME" ]; then
    printf "$WAKETIME\t`date -r $WAKETIME`\n" >> $WAKELOG
fi


# ----- Network Reset Section -----
# If a lockfile exists and it's older than 5 minutes; delete it
if [ -e $LOCKFILE ]; then
     LOCKFILECREATED=`stat -f "%B" $LOCKFILE`
     if [ "$(($NOW-$LOCKFILECREATED))" -gt "300" ]; then
          rm $LOCKFILE
     fi
fi


# Determine what kind of machine this is running on (Variable set for legibility)
if [  "$MACTYPE" == "MacBook" ] || [ "$MACTYPE" == "MacBookPro" ] || [ "$MACTYPE" == "MacBookAir" ] || [ "$MACTYPE" == "PowerBook" ] ||[ "$MACTYPE" == "iBook"  ]; then
     FORMFACTOR="Laptop"
elif [ "$MACTYPE" == "MacPro" ] || [ "$MACTYPE" == "iMac" ] || [ "$MACTYPE" == "Macmini" ] || [ "$MACTYPE" == "PowerMac" ]; then
    FORMFACTOR="Desktop"
elif [ "$MACTYPE" == "RackMac" ] || [ "$MACTYPE" == "Xserve" ]; then
    FORMFACTOR="Server"
    # I'm not sure why you'd have a server using Wifi, but...
elif [ "$MACTYPE" == "AppleTV" ] || [ "$MACTYPE" == "iPod" ] || [ "$MACTYPE" == "iPad" ] || [ "$MACTYPE" == "iPhone" ]; then
    FORMFACTOR="iDevice"
    # Seriously???
    # Does the script work?
else
    FORMFACTOR="Unknown"
fi

# If the machine is a desktop whose ethernet cable is plugged in...
if [ "$FORMFACTOR" == "Desktop" ] && [ "$ETHERNETSTATUS" == "active" ]
    # ...and which has an IP address, disable reconnection attempt
    if [ "$ETHERNETIP" != "" ] || [ "`echo $ETHERNETIP | sed -e '/^169.*/d'`" != "" ]; then
        exit 0
    fi
fi



# Make sure there is no lockfile
if [ ! -e $LOCKFILE ]; then

     # If Wifi is disabled, disable reconnection attempt
     if [ "$AIRPORTENABLED" == "Disabled" ]; then
          exit 0
     fi

     # If machine has been on for less than 4 minutes, disable reconnection attempt
     if [ "$(($NOW-$STARTTIME))" -gt "240" ]; then
          exit 0
     fi

     # If machine has been awake less than 2 minutes, disable reconnection attempt
     if [ "$(($NOW-$WAKETIME))" -lt "120" ]; then
          exit 0
     fi

     # If reset conditions are met and Airport has no IP address, reset wifi connection
     if [ "$AIRPORTIP" == "" ] || [ "`echo $AIRPORTIP | sed -e '/^169.*/d'`" == "" ]; then
          # Create lockfile
          touch $LOCKFILE
          # Multiple network locations exist; switch to alternate network location and cycle the power on the WiFi card
          if [ "$NETWORKLOCATIONS" -gt "1" ]; then
               scselect "$ALTERNATENETWORKLOCATION"
               sleep 5
               networksetup -setairportpower off
               sleep 5
               networksetup -setairportpower on
               sleep 50
               # Wifi is still offline; log this, switch back to original network location, and cycle the power on the WiFi card
               if [ "$AIRPORTIP" == "" ] || [ "`echo $AIRPORTIP | sed -e '/^169.*/d'`" == "" ]; then
                    printf "$TIME\t$USER\t$MACHINENAME\tWarning\tNo valid Wifi IP address for 3 minutes - Switching to Original Configuration\n" >> $LOGFILE
                    scselect "$ORIGINALNETWORKLOCATION"
                    sleep 5
                    networksetup -setairportpower off
                    sleep 5
                    networksetup -setairportpower on
                    sleep 60
                    # If WiFi is still offline, log failure - no more reconnection attempts for now
                    if [ "$AIRPORTIP" == "" ] || [ "`echo $AIRPORTIP | sed -e '/^169.*/d'`" == "" ]; then
                         printf "$TIME\t$USER\t$MACHINENAME\tFailure\tWifi reconnection failed - Perhaps signal strength is low" >> $LOGFILE
                         exit 1
                    # If Wifi is online after switching back to "original" log this
                    else
                         printf "$TIME\t$USER\t$MACHINENAME\tWarning\tOriginal Configuration is working\n" >> $LOGFILE
                         exit 0
                    fi
               # Wifi is online after switching to "alternate" log this
               else
                    printf "$TIME\t$USER\t$MACHINENAME\tWarning\tAlternate Configuration is working\n" >> $LOGFILE
                    exit 0
               fi

          # Only one network location exists, cycle Airport power and hope that works
          else
               networksetup -setairportpower off
               sleep 30
               networksetup -setairportpower on
               sleep 50
               if [ "$AIRPORTIP" == "" ] || [ "`echo $AIRPORTIP | sed -e '/^169.*/d'`" == "" ]; then
                    printf "$TIME\t$USER\t$MACHINENAME\tFailure\tWifi connection still down - Add another network location for better results" >> $LOGFILE
                    exit 1
               fi
          fi
     fi
fi

exit 0