#!/bin/bash
#
# Author: Georg Voell - georg.voell@standby.cloud
# Version: @(#)vip-management 3.2.0 09.09.2024 (c)2024 Standby.cloud
# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
#
# This script can be used free of charge. Use it as is or customize as needed. It is not guaranteed to be
# error free and you will not be reimbursed for any damage it may cause.
#
#@  Add or delete secondary private IP (Virtual IP)
#@  Docs: https://docs.oracle.com/en-us/iaas/Content/Network/Tasks/managingIPaddresses.htm
#@
#@Usage: vip-management [options] action [ipv4]
#@  Options: -h, --help                 : Displays helptext.
#@           -v, --version              : Displays the version of the script.
#@  Action:
#@      show: Show current state (default).
#@       add: Attach ipv4 to instance.
#@    delete: Detach ipv4 from instance.
#@     route: Add ipv4 to default gateway.
#@  ipv4:
#@    A valid and unused IPv4
#@
#@Examples:
#@  vip-management add 10.0.1.50
#@    Create a second interface using private IP (from primary VNIC).
#@  vip-management delete 10.0.1.50
#@    Delete the second interface.
#
# Exit codes:
#  01: Unknown or wrong parameter and only LINUX supported and script needs to be executed with ROOT privileges.
#  02: Unknown action.
#  03: No 'ifconfig' or 'ip' in PATH.
#  04: No suitable interface found in 'ifconfig'.
#  05: No IPv4 found in interface.
#  06: VIP already defined (add) or does not exists (delete)
#  99: User interrupt.
#
# See also:
#  **install-scripts**(1)
#
# Update history:
#
# V 3.0.0 14.05.2021 New version
# V 3.0.1 21.05.2021 Try sudo if user isn't root
# V 3.0.2 22.05.2021 New action: show
# V 3.1.0 05.06.2023 New copyright
# V 3.2.0 09.09.2024 New minor version: Options
#

# Find executable bash library and source it
lib=`which lib.bash 2>/dev/null | sed 's|^no 'lib.bash' in .*||'`
if [ "$lib" != "" ]; then
	source "$lib"
else
	progdir=`dirname "$0"`
	if [ -r "${progdir}/lib.bash" ]; then
		source "${progdir}/lib.bash"
	else
		echo "Unexpected error: Unable to locate bash library 'lib.bash'."
		exit 1
	fi
fi

# Convert Netmask to CIDR
function NetmaskToCIDR() {
	local netmask=${1}
	local cidr=0
	
	if [ "$netmask" != "" ]; then
		case "$netmask" in
			128.0.0.0)
				cidr=1
				;;
			192.0.0.0)
				cidr=2
				;;
			224.0.0.0)
				cidr=3
				;;
			240.0.0.0)
				cidr=4
				;;
			248.0.0.0)
				cidr=5
				;;
			252.0.0.0)
				cidr=6
				;;
			254.0.0.0)
				cidr=7
				;;
			255.0.0.0)
				cidr=8
				;;
			255.128.0.0)
				cidr=9
				;;
			255.192.0.0)
				cidr=10
				;;
			255.224.0.0)
				cidr=11
				;;
			255.240.0.0)
				cidr=12
				;;
			255.248.0.0)
				cidr=13
				;;
			255.252.0.0)
				cidr=14
				;;
			255.254.0.0)
				cidr=15
				;;
			255.255.0.0)
				cidr=16
				;;
			255.255.128.0)
				cidr=17
				;;
			255.255.192.0)
				cidr=18
				;;
			255.255.224.0)
				cidr=19
				;;
			255.255.240.0)
				cidr=20
				;;
			255.255.248.0)
				cidr=21
				;;
			255.255.252.0)
				cidr=22
				;;
			255.255.254.0)
				cidr=23
				;;
			255.255.255.0)
				cidr=24
				;;
			255.255.255.128)
				cidr=25
				;;
			255.255.255.192)
				cidr=26
				;;
			255.255.255.224)
				cidr=27
				;;
			255.255.255.240)
				cidr=28
				;;
			255.255.255.248)
				cidr=29
				;;
			255.255.255.252)
				cidr=30
				;;
			255.255.255.254)
				cidr=31
				;;
			255.255.255.255)
				cidr=32
				;;
		esac
	fi
	
	echo "$cidr"
}

# Add a second IP as a Virtual IP
function AddVIP() {
	local interface=${1}
	local vip=${2}
	local netmask=${3}
	local broadcast=${4}
	local cidr=0
	local filename=""
	local stat=0
	
	# Create entry in ifconfig
	if [ "$interface" != "" -a "$vip" != "" -a "$netmask" != "" ]; then
		filename="/etc/sysconfig/network-scripts/ifcfg-${interface}:vip"
		cidr=`NetmaskToCIDR "$netmask"`
		if [ "$broadcast" != "" ]; then
			ip addr add "${vip}/${cidr}" dev "$interface" label "${interface}:vip" broadcast "$broadcast"
			stat=$?
		else
			ip addr add "${vip}/${cidr}" dev "$interface" label "${interface}:vip"
			stat=$?
		fi
	
		# Create file to make it persitent abfter reboot
		if [ $stat -eq 0 ]; then
			echo 'DEVICE="'$interface':vip"' > $filename
			echo "BOOTPROTO=static" >> $filename
			echo "IPADDR=$vip" >> $filename
			echo "NETMASK=$netmask" >> $filename
			if [ "$broadcast" != "" ]; then
				echo "BROADCAST=$broadcast" >> $filename
			fi
			echo "ONBOOT=yes" >> $filename
			
			# Display success
			echo "VIP '$vip' added to interface '${interface}:vip'."
		fi
	fi
}

# Delete a second IP as a Virtual IP
function DeleteVIP() {
	local interface=${1}
	local vip=${2}
	local netmask=${3}
	local cidr=0
	local filename=""
	local stat=0

	# Create entry in ifconfig
	if [ "$interface" != "" -a "$vip" != "" -a "$netmask" != "" ]; then
		filename="/etc/sysconfig/network-scripts/ifcfg-${interface}:vip"
		cidr=`NetmaskToCIDR "$netmask"`
		ip addr del "${vip}/${cidr}" dev "$interface"
		stat=$?
	
		if [ $stat -eq 0 ]; then
			# Delete file to make it persitent abfter reboot
			rm -f $filename
	
			# Display success
			echo "VIP '$vip' deleted from interface '${interface}:vip'."
		fi
	fi
}

# Preset
action=""
vip=""

# Check parameters: Loop until all parameters are used up
while [ $# -gt 0 ]; do
	pname=${1}
	case "$pname" in
		-v | --version)
			shift
			showversion=true
			;;
		-h | --help)
			shift
			showhelp=true
			;;
		*)
			shift
			paramck=`echo "$pname" | grep '^-'` # Types don't begin with '-'
			if [ "$paramck" != "" ]; then
				errstr="Unknown option '$pname'."
			else
				if [ "$action" = "" ]; then
					action=`echo "$pname" | tolower`
				else
					if [ "$vip" = "" ]; then
						vip="$pname"
					else
						errstr="VIP was already specified '$vip'. Unknown additional parameter: '$pname'."
					fi
				fi
			fi
	esac
done

# Plausibility check
# Check if we are running on Linux
if [ "$OS" != "Linux" ]; then
	errstr="This script only supports LINUX."
else
	if [ "$action" = "" ]; then
		action="show"
	elif [ "$action" != "show" -a "$action" != "route" -a "$vip" = "" ]; then
		errstr="Please use this script with an action (add or delete) and a virtual ip as second paramater."
	fi
fi

# Display help or error message
DisplayHelp

### Main

if [ "$USER" != "root" ]; then
	# Try sudo
	check-sudo
	stat=$?

	if [ $stat -eq 0 ]; then
		sudo --preserve-env=PATH "$script" "$action" "$vip"
	else
		exitcode=1
		errormsg $exitcode "Need to be root."
	fi
else
	ifconfig=`filecheck -x ifconfig`
	iproute=`filecheck -x ip`
	if [ "$ifconfig" = "" -o "$iproute" = "" ]; then
		exitcode=3
		errormsg $exitcode "No 'ifconfig' or 'ip' in PATH."
	else
		result=`"$iproute" route show 2>/dev/null | grep '^default ' | tail -n 1`
		if [ "$result" != "" ]; then
			gateway=`echo "$result" | cut -d' ' -f3`
			iface=`echo "$result" | cut -d' ' -f5`
		fi
		
		result=`echo "$iface" | grep ':vip$'`
		if [ "$result" != "" ]; then
			iface=`echo "$iface" | sed 's|:vip$||'`
			viproute=true
		else
			viproute=false
		fi

		"$ifconfig" "$iface" > $scratchfile 2>/dev/null
		lip=`grep "inet " $scratchfile | tail -n 1 | awk '{print $2}'`
		lipv6=`grep "inet6 " $scratchfile | tail -n 1 | awk '{print $2}'`
		result=`grep '^'"${iface}"': .*<UP,' $scratchfile`

		if [ "$result" = "" ]; then
			exitcode=4
			errormsg $exitcode "No suitable interface found in 'ifconfig'."
		else
			if [ "$lip" = "" ]; then
				exitcode=5
				errormsg $exitcode "No IPv4 found in interface '$iface'."
			else
				result=`grep 'inet ' $scratchfile | tail -n 1 | tr -s ' ' | sed 's|^ ||'`
				ip=`echo "$result" | cut -d' ' -f2`
				netmask=`echo "$result" | cut -d' ' -f4`
				broadcast=`echo "$result" | cut -d' ' -f6`
				
				# Check if VIP is already defined
				"$ifconfig" "${iface}:vip" > $scratchfile
				result=`grep 'inet ' $scratchfile | tail -n 1 | tr -s ' ' | sed 's|^ ||'`
				if [ "$result" != "" ]; then
					oldvip=`echo "$result" | cut -d' ' -f2`
				else
					oldvip=""
				fi
				
				"$iproute" route show > $scratchfile
				defroute=`grep '^default via' $scratchfile`
					
				case "$action" in
					show)
						if [ "$oldvip" != "" ]; then
							echo "Private ip_v4 on interface '$iface': '$ip'."
							echo "VIP attached to interface '${iface}:vip': '$oldvip'."
							if [ "$viproute" = true ]; then
								echo "VIP attached to default route."
							else
								echo "VIP not attached to default route."
							fi
							echo "Default route: $defroute"
						else
							echo "Private ip_v4 on interface '$iface': '$ip'."
							echo "No VIP attached to interface '$iface'."
							if [ "$viproute" = true ]; then
								echo "VIP attached to default route."
							else
								echo "VIP not attached to default route."
							fi
							echo "Default route: $defroute"
						fi
						;;
					route)
						if [ "$oldvip" != "" ]; then
							result=`echo "$defroute" | sed 's|src '$oldvip'||'`
							$iproute route replace $result src $oldvip
							$iproute route show > $scratchfile
							defroute=`grep '^default via' $scratchfile`
							echo "Default route: $defroute"
						else
							echo "No VIP attached to interface '$iface'."
						fi
						;;
					add)
						if [ "$vip" = "$ip" ]; then
							exitcode=6
							errormsg $exitcode "VIP must differ from private ip on interface '${iface}'."
						else
							if [ "$oldvip" != "" ]; then
								exitcode=6
								errormsg $exitcode "VIP for '${iface}:vip' already defined: '$oldvip'."
							else
								AddVIP "$iface" "$vip" "$netmask" "$broadcast"
							fi
						fi
						;;
					delete)
						if [ "$oldvip" = "" ]; then
							exitcode=6
							errormsg $exitcode "VIP for '${iface}:vip' not defined."
						else
							if [ "$oldvip" != "$vip" ]; then
								exitcode=6
								errormsg $exitcode "Existing VIP '$oldvip' for '${iface}:vip' differs from VIP '$vip'."
							else
								result=`echo "$defroute" | grep "src $vip"`
								if [ "$result" != "" ]; then
									result=`echo "$defroute" | sed 's|src '$vip'||'`
									$iproute route replace $result
								fi
								
								DeleteVIP "$iface" "$vip" "$netmask"
							fi
						fi
						;;
					*)
						exitcode=2
						errormsg $exitcode "Unknown action: '$action'."
				esac
			fi
		fi
	fi
fi

# Cleanup and exit
Cleanup
exit $exitcode