#!/bin/bash
# $Id$
# Configures virtualbox for Magellan-Linux guests

# get INSTALL_DIR location
source /etc/vbox/vbox.cfg

VBOXVERSION="$(< ${INSTALL_DIR}/version)"
VBOXMODEXT=ko
VBOXGUESTMODULE=vboxguest
VBOXSFMODULE=vboxsf
VBOXVIDEOMODULE=vboxsf
KERNELMODULES=( "${VBOXGUESTMODULE}" "${VBOXSFMODULE}" "${VBOXVIDEOMODULE}" )

COLRED="\033[1;6m\033[31m"
COLGREEN="\033[1;6m\033[32m"
COLDEFAULT="\033[0m"

if [[ ${NOCOLORS} = true ]]
then
	COLRED=""
	COLGREEN=""
	COLDEFAULT=""
fi

die() { echo -e "${COLRED}$@${COLDEFAULT}"; exit 1; }
mecho() { echo -e "${COLGREEN}$@${COLDEFAULT}"; }
usage()
{
	echo "Usage: $(basename $0 .sh) [opts]"
	echo "Options are:"
	echo " --kernel-version - build modules for given kernel version not current"
	echo " --kernel-sources - use kernel sources different from default path"
	echo " --force          - force a rebuild of the kernel modules even if they exist"
	echo " --verbose        - be verbose while building the modules"
	echo " --help           - show this help"
	exit
}

# must be root
[[ $(id -u) != 0 ]] && die "You must be r00t!"

# check for given argvs
for i in $*
do
	case $1 in
		--kernel-version) shift; KERNEL_VERSION="$1" ;;
		--kernel-sources) shift; KERNEL_SOURCES="$1" ;;
		--force) FORCED_REBUILD="1" ;;
		--verbose) VERBOSE="1" ;;
		--help) usage ;;
	esac
	shift
done

# some sane defaults
[[ -z ${KERNEL_VERSION} ]] && KERNEL_VERSION="$(uname -r)"
[[ -z ${KERNEL_SOURCES} ]] && KERNEL_SOURCES="/lib/modules/${KERNEL_VERSION}/source"
[[ -z ${FORCED_REBUILD} ]] && FORCED_REBUILD="0"
[[ -z ${VERBOSE} ]] && VERBOSE="0"
[[ ${VERBOSE} = 0 ]]  && makequiet="-s"

mecho "Running $(basename $0) for kernelversion ${KERNEL_VERSION} ..."

# first stop the vboxguest service
if [[ -x $(which systemctl) ]]
then
	systemctl is-active vboxguest.service && systemctl stop vboxguest.service
	systemctl is-enabled vboxguest.service && systemctl disable vboxguest.service
elif [[ -x /etc/rc.d/init.d/vboxguest ]]
then
	/etc/rc.d/init.d/vboxguest stop
	rc-config del vboxguest
fi

# check module version and recompile if it doesen't fit else break here
compile="yes"
for module in ${KERNELMODULES[*]}
do
	if [[ -f /lib/modules/${KERNEL_VERSION}/misc/${module}.${VBOXMODEXT} ]]
	then
		myver=$(modinfo -k ${KERNEL_VERSION} -F version ${module} | sed "s:\(.*\)_.*:\1:")
		if [[ ${VBOXVERSION} = ${myver} ]] && [[ ${FORCED_REBUILD} = 0 ]]
		then
			compile="no"
		fi
	fi
done

# try to unload the modules in reverse order to honor dependencies
count=${#KERNELMODULES[*]}
for (( i=count-1; i>=0; i-- ))
do
	if [[ -f /lib/modules/${KERNEL_VERSION}/misc/${KERNELMODULES[${i}]}.${VBOXMODEXT} ]]
	then
		if [[ -n $(grep "${KERNELMODULES[${i}]} " /proc/modules 2> /dev/null) ]]
		then
			mecho "Unloading ${KERNELMODULES[${i}]} module ..."
			modprobe -r ${KERNELMODULES[${i}]}
		fi
	fi
done

if [[ ${compile} = yes ]]
then
	if [ ! -f ${KERNEL_SOURCES}/include/linux/version.h ]
	then
		die "No kernel sources for kernel ${KERNEL_VERSION} found! Aborting."
	fi

	for module in ${KERNELMODULES[*]}
	do
		if [[ -f /lib/modules/${KERNEL_VERSION}/misc/${module}.${VBOXMODEXT} ]]
		then
			mecho "Removing old ${module} module ..."
			rm -f /lib/modules/${KERNEL_VERSION}/misc/${module}.${VBOXMODEXT}
		fi
	done

	# compile the modules
	pushd ${INSTALL_DIR}/additions/src > /dev/null
	for module in ${KERNELMODULES[*]}
	do
		mecho "Compiling ${module} module ..."
		make ${makequiet} -C ${module} KBUILD_VERBOSE=${VERBOSE} clean || die "mod-compile ${module}"

		# need some symver from vboxmodule (must be run after clean!)
		if [[ ${module} = ${VBOXSFMODULE} ]]
		then
			[[ -f ${VBOXGUESTMODULE}/Module.symvers ]] && cp ${VBOXGUESTMODULE}/Module.symvers ${module}
		fi

		make ${makequiet} -C ${module} KBUILD_VERBOSE=${VERBOSE} || die "mod-compile ${module}"

		# install the modules
		install -d /lib/modules/${KERNEL_VERSION}/misc
		install -m0644 ${module}/${module}.${VBOXMODEXT} /lib/modules/${KERNEL_VERSION}/misc || die "mod-install ${module}"
	done
	# do no clean before all modules are build, or required symbols and objects get deleted
	for module in ${KERNELMODULES[*]}
	do
		# clean up
		make ${makequiet} -C ${module} KBUILD_VERBOSE=${VERBOSE} clean || die "mod-compile ${module}"
	done
	popd > /dev/null

	# calc module dependencies
	mecho "Calculating module dependencies ..."
	depmod -a ${KERNEL_VERSION}

	# re-read udev rules to grant the right permissions
	if [[ -x $(which udevadm) ]]
	then
		mecho "Reloading udev configuration ..."
		udevadm control --reload-rules
	fi
fi

# load the module
if [[ x$(uname -r) = x${KERNEL_VERSION} ]]
then
	for module in ${KERNELMODULES[*]}
	do
		mecho "Loading kernel-module ${module} ..."
		modprobe ${module}
	done

	if [ $(echo ${KERNEL_VERSION%%-*} | sed 's:\.::g') -ge 2639 ]
	then
		# fixes NMI warnings with kernels >=2.6.31:
		# vboxdrv: Warning: 2.6.31+ kernel detected. Most likely the hardware performance
		# vboxdrv: counter framework which can generate NMIs is active.
		mecho "Disabled hardware performance counter NMIs ..."
		echo 2 > /proc/sys/kernel/perf_event_paranoid

	elif [ $(echo ${KERNEL_VERSION%%-*} | sed 's:\.::g') -ge 2631 ]
	then
		# fixes NMI warnings with kernels >=2.6.31:
		# vboxdrv: Warning: 2.6.31+ kernel detected. Most likely the hardware performance
		# vboxdrv: counter framework which can generate NMIs is active.
		mecho "Disabled hardware performance counter NMIs ..."
		echo 2 > /proc/sys/kernel/perf_counter_paranoid
	fi
else
	echo -e ${COLRED}
	echo "Your current running kernel does not match the the module target."
	echo "You must boot into your target kernel and load the modules manually,"
	echo "before you can use virtualbox."
 	echo -en ${COLDEFAULT}
fi

# start the vboxguest service
if [[ -x $(which systemctl) ]]
then
	systemctl enable vboxguest.service
	systemctl start vboxguest.service
elif [[ -x /etc/rc.d/init.d/vboxguest ]]
then
	rc-config add vboxguest
	/etc/rc.d/init.d/vboxguest stop
fi

echo
mecho "Virtualbox guest-additions are now configured for your system."
echo

exit 0