#!/bin/bash
#
# Command line WiFi connector. Only WPA and non-encryption supported
#
# Okt 31 09:06:31 CET 2007
# Fri May 23 16:02:39 CEST 2008 / added WPA option
# Thu May 29 19:56:10 CEST 2008 / WPA key input is now invisible
#                                 added rescanning if SSID input is blank
# Thu Sep 18 10:30:15 CEST 2008 / added function to scan available interface
#                                 and wpa_supplicant binary check
# Wed Aug 19 11:37:54 CEST 2009 / more optimized
# Mon Oct  3 14:53:59 CEST 2016 / dialog'ed
#
#
IFACE=$1
umask 0002 # secure tmp files
pkill wpa_supplicant # kill existing wpa processes

DIALOGBIN=`which dialog`
if [[ -z $DIALOGBIN ]] ; then
        DIALOG=
else
        #DIALOGBIN="$DIALOGBIN --backtitle \"Wireless connection wizard\""
        DIALOG=1
        TMP=/tmp/tmp.$$
        trap "rm -rf $TMP" INT TERM EXIT
fi

# Check if Parameter is a valid Interface to use. If not, the Script proposes
# the Interface he found with iwconfig
ifconfig $IFACE > /dev/null
if [ "$?" -eq "1" ] ; then
        FINDIFACE=`iwconfig |grep IEEE |awk '{print $1}'`
        if [[ $DIALOG ]]; then
                $DIALOGBIN --title "Interface $1 not found" --msgbox "But found $FINDIFACE. \nContinuing with this interface" 8 50
        else
                clear
                echo "Interface $1 not found..."
                echo "...but found $FINDIFACE. Press [ENTER] to continue with this Interface."
                read
        fi
        IFACE=$FINDIFACE
fi

# Output a Usage if no Parameter is given
if [ "$1" == "" ] ; then
        echo "Usage: $0 interface"
        exit 1
fi
clear
ifconfig $IFACE up

if [[ $DIALOG ]]; then
        $DIALOGBIN --infobox "Scanning for Access Points on $IFACE ..." 3 50
        SSIDLIST=`iwlist $IFACE scanning |grep ESSID |cut -f2 -d\" |grep -v "\\x00"` 
        SSIDLISTSIZE=`echo $SSIDLIST |wc -w`
        $DIALOGBIN  --title "Enter ESSID you want to connect or leave blank to rescan" --inputbox "$SSIDLIST" `expr 10 + $SSIDLISTSIZE` 80 2>$TMP
        SSID=`cat $TMP`
else
        echo "Scanning for Access Points in $IFACE ..."
        echo ""
        iwlist $IFACE scanning |grep ESSID
        echo ""
        echo "Enter ESSID you want to connect or leave blank to rescan and press [ENTER]:"
        read SSID
fi

# If the Input is empty, the Script loops over the scan and asks each time to enter
# a SSID to continue with the connection
while [[ -z $SSID ]]; do
        clear
        if [[ $DIALOG ]]; then
                $DIALOGBIN --infobox "Rescanning for Access Points on $IFACE ..." 3 50
                SSIDLIST=`iwlist $IFACE scanning |grep ESSID |cut -f2 -d\" |grep -v "\\x00"`
                SSIDLISTSIZE=`echo $SSIDLIST |wc -w`
                $DIALOGBIN --title "Enter ESSID you want to connect or leave blank to rescan" --inputbox "$SSIDLIST" `expr 10 + $SSIDLISTSIZE` 80 2>$TMP
                SSID=`cat $TMP`
        else
                echo "Rescanning for Access Points..."
                iwlist $IFACE scanning |grep ESSID
                echo "Enter ESSID you want to connect or leave blank to rescan and press [ENTER]:"
                echo ""
                read SSID
        fi
done

# Set the entered SSID and wait 1 Second
iwconfig $IFACE ESSID "$SSID"
sleep 1

# Encryption select
if [[ $DIALOG ]]; then
        $DIALOGBIN --title "Encryption" --radiolist "Please select Security for $SSID:" 10 60 2 1 None off 2 WPA on 2>$TMP
        ENCRYPT=`cat $TMP`
else
        clear
        echo "You are connecting to $SSID"

        echo "Please select Security: "
        echo "1: None"
        echo "2: WPA"
        read ENCRYPT
fi

case "$ENCRYPT" in
        1)
                ;;
        2)
                # Check if wpa_supplicant is installed and quit if not
                if [[ ! `which wpa_supplicant` ]]; then
                        if [[ $DIALOG ]]; then
                                $DIALOGBIN --infobox "wpa_supplicant was not found on this system. Aborted" 3 60
                        else
                                echo "wpa_supplicant was not found on this system. Aborted"
                        fi
                        exit 1
                fi
                if [[ $DIALOG ]]; then
                        $DIALOGBIN --passwordbox "Enter Passphrase" 10 60 2>$TMP 
                        PASS=`cat $TMP`
                else
                        echo "Enter Passpharse: "
                        read -s PASS
                fi

                # Store the entered Passphrase as WPA Key and start wpa_supplicant
                # process in the background
                wpa_passphrase $SSID $PASS > /etc/wpa_supplicant/wpa_supplicant.conf
                chmod 600 /etc/wpa_supplicant/wpa_supplicant.conf
                wpa_supplicant -B -Dwext -i$IFACE -c/etc/wpa_supplicant/wpa_supplicant.conf &
                ;;
        *)
                if [[ $DIALOG ]]; then
                        $DIALOGBIN --infobox "Wrong selection. Aborted!" 3 60
                else
                        echo "Wrong selection. Aborted!"
                fi
                exit 1
                ;;
esac

# Renew the IP and quit smoothly
if [[ $DIALOG ]]; then
        $DIALOGBIN --infobox "Obtaining IP Address\n\n If this process takes longer than 15s,\n you may enter a wrong key or no DHCP server present" 6 60
        dhclient -q -1 $IFACE
else
        dhclient -v -1 $IFACE
fi