Update MACchange.sh

added (MAJOR): 
1. Better macchanger installation check 
2. Additional mac randomization options to user
3. support wlan and ethernet (as opposed to wlan only)
4. check connectivity before randomization 
5. option to revert back to original mac
6. store logs and minor ui interface improvement

Author: 4n33sh

MACchange.sh

@@ -1,78 +1,80 @@
-#! /bin/bash
+#!/bin/bash
 
-echo "What type of network do you wish to randomise?"
+#check for root privileges
+if [ "$EUID" -ne 0 ]; then
+    echo "This script must be run by a user with sudo privileges."
+    exit 1
+fi
+
+#check if macchanger is installed (or not)
+if ! command -v macchanger &> /dev/null; then
+    echo "Macchanger binary not found. Installing..."
+    sudo apt-get update -y && sudo apt-get install macchanger -y
+fi
+
+echo "What type of network do you wish to randomize?"
 echo " "
 echo "#1. eth"
 echo "#2. wlan"
 echo " "
 read input
 
-# Check for root privileges
-# $EUID is an env variable. Contains the id-value of user currently utilising the script.
-if [ "$EUID" -ne 0 ]; then
-  echo "This script must be run by an user with sudo privileges (root works but is generally not recommended)."
-  exit 1
-fi
-macchanger_bincheck=`which macchanger | grep -o macchanger > /dev/null &&  echo 0 || echo 1`
-if ["$macchnager_bincheck" -ne 1]; then
-  echo "Mac changer binary not detected! Running Automated Installation process..."
-  sudo apt-get update -y && sudo apt-get install macchanger | yes
-fi
+#list all the available interfaces and get user-input
+if [[ $input == 1 ]]; then
+    interfaces=$(ip link show | grep eth | awk '{print $2}' | tr -d ':')
+    echo "Available Ethernet interfaces: $interfaces"
+    read -p "Enter the Ethernet interface you want to randomize: " type_eth
 
-# Checking user input.
-if [[ $input == 1 ]]
-then
-	echo " "
-	echo "Enter the ethernet device you want to randomise: (e.g. eth0 [or] eth1 [or] eth2)"
-	echo " "
-	read type_eth
-	
-	command1=`ifconfig | grep $type_eth`
+    # Validate interface
+    if ! ifconfig $type_eth &> /dev/null; then
+        echo "$type_eth not found. Please check the device name."
+        exit 1
+    fi
 
-	# Checking if the returned output from 'command1' has any info about -
- 	# the existence of eth connection. If the string is empty, then user is shown to the basic troubleshoot.
-	if [ -z "$command1" ];
-	then
-	   	echo "No eth0 connection! Failed to randomise MAC of eth0."
-		echo " "
-		echo "Troubleshooting: "
-		echo "1. Please try entering an existing ethernet connection (i.e. check your input)"
-		echo "2. Please try checking the connection of ethernet cable to your computer/VM is established."
-	else
-		# Random mac could be implemented by utilizing env variable $RANDOM
-		mac1="00:11:22:33:44:55"
+    #randomize the MAC address using macchanger
+    echo "Randomizing MAC for $type_eth..."
+    sudo macchanger -r $type_eth
+    echo "Randomized MAC for $type_eth"
+    
+else
+    interfaces=$(ip link show | grep wlan | awk '{print $2}' | tr -d ':')
+    echo "Available WLAN interfaces: $interfaces"
+    read -p "Enter the WLAN interface you want to randomize: " type_wlan
 
-	    	sudo ifconfig $type_eth down
-		sudo ifconfig $type_eth hw ether $mac1
-		sudo ifconfig $type_eth up
-		echo " "
-		echo "Changed MAC of $type_eth ."
-		echo "Current MAC of $type_eth is: $mac1"
-	fi
+    #Validate interface
+    if ! ifconfig $type_wlan &> /dev/null; then
+        echo "$type_wlan not found. Please check the device name."
+        exit 1
+    fi
 
-else
-	echo " "
-	echo "Enter the wlan/NIC device you want to randomise: (e.g. wlan0 [or] wlan1 [or] wlan2)"
-	echo " "
-	read type_wlan
-	echo " "
+    #randomize MAC address using macchanger
+    echo "Randomizing MAC for $type_wlan..."
+    sudo macchanger -r $type_wlan
+    echo "Randomized MAC for $type_wlan"
+fi
 
-	command2=`ifconfig | grep $type_wlan`
+#check global network connectivity after MAC change (ping to google dns for verif.)
+echo "Checking network connectivity..."
+if ! ping -c 3 8.8.8.8 &> /dev/null; then
+    echo "Network is not reachable after changing MAC address. Check your connection."
+else
+    echo "Network is reachable."
+fi
 
- 	# The same for this part of else-code. (except it is for wlan interface)
-	if [ -z "$command2" ];
-	then
-   	 	echo "wlan0/NIC Adapter not detected. Failed to randomise MAC of wlan0."
-		echo " "
-		echo "Troubleshooting: "
-		echo "1. Please try entering an existing NIC (i.e. check your input)"
-		echo "2. Please try checking the connection of NIC to your computer/VM is established."
-		echo " "
-	else
-		echo "MAC Change (wlan0) status: "
-		echo " "
-	   	sudo macchanger -r $type_wlan
-		echo " "
-		echo "Changed MAC of NIC/$type_wlan"
-	fi
+#offer user to revert to original/previous MAC address
+read -p "Would you like to revert to the original MAC address? (y/n): " revert
+if [ "$revert" == "y" ]; then
+    if [[ $input == 1 ]]; then
+        sudo macchanger -p $type_eth
+        echo "Original MAC restored for $type_eth."
+    else
+        sudo macchanger -p $type_wlan
+        echo "Original MAC restored for $type_wlan."
+    fi
 fi
+
+#log the MAC change event to a log file
+log_file="/var/log/mac_randomizer.log"
+echo "$(date) - Changed MAC for $type_eth/$type_wlan" >> $log_file
+
+echo "Script finished."