#!/sbin/runscript
# Copyright 2009-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

# To use this, symlink a target kvm instance to this script.
# Literally, ln -s qemu /etc/init.d/<vm-type>.<vmname>
# then have a config named /etc/conf.d/<vm-type>.<vmname>
#
# Allowed vm-types are currently qemu and kvm.


VMNAME=${SVCNAME#*.}
VMTYPE=${SVCNAME%.*}
VM_BINARY=
PIDFILE=/run/vm/${SVCNAME}.pid
MONITOR=/run/vm/${SVCNAME}.monitor
QTAP_FILE=/run/vm/${SVCNAME}.qtap

ENABLE_SDL=

discern_vm_binary() {
	case "$VMTYPE" in
		kvm)
			VM_BINARY=`type -p qemu-kvm`
			[ -z "$VM_BINARY" ] && VM_BINARY=`type -p kvm`
			;;
		qemu)
			VM_BINARY=`type -p qemu`
			;;
		*)
			eerror "Failed to discern the binary for $VMTYPE"
			;;
	esac
	return 0
}

discern_foreground() {
	if [ -n "$VNC" ]; then
		ewarn "VNC option is going away; set FOREGROUND=\"vnc=${VNC}\" instead"
		FOREGROUND="vnc=${VNC}"
	fi
	case "${FOREGROUND:-none}" in
		vnc*)
			VNC=${FOREGROUND#*=}
			if [ -z "$VNC" ]; then
				eerror "FOREGROUND vnc is incorrectly set; must specify an address (:1 for example)"
				return 1
			fi
			;;
		sdl*)
			ENABLE_SDL=${FOREGROUND#*=}
			if [ -z "${ENABLE_SDL}" ]; then
				eerror "FOREGROUND sdl is incorrectly set; must specify a DISPLAY address"
				return 1
			fi
			;;
		none)
			;;
		*)
			eerror "Unknown FOREGROUND setting: $FOREGROUND"
			return 1
			;;
	esac
	return 0
}

DROP_USER=${DROP_USER:-nobody}
MEMORY=${MEMORY:-512M}
TIMEOUT=${TIMEOUT:-300}
SMP=${SMP:-1}
export KVM_USER=${KVM_USER:-"root"}

extra_commands="reboot"

depend() {
	if [ "$VMNAME" = "$SVCNAME" ]; then
		return 0
	fi

	sanity_check || return 1

	case "$NIC_TYPE" in
		br)
			need ${NIC_NET_DEPS-net.br0}
			;;
	esac
}

send_command() {
	local command="socat -u - UNIX-CONNECT:${MONITOR}"
	type -p nc6 > /dev/null && command="nc6 -U ${MONITOR} --send-only"
	echo "$@" | ${command} > /dev/null 2>&1
}

sanity_check() {
	if [ "${VMNAME}" = "${SVCNAME}" ]; then
		eerror "You have to create an init script for each vm:"
		eerror " ln -s vm /etc/init.d/vm.vmname"
		return 1
	fi

	DISKIMAGE=$(readlink -f "${DISKIMAGE}")
	if [ ! -f "${DISKIMAGE}" -a ! -b "${DISKIMAGE}" ]; then
		eerror "couldn't find \$DISKIMAGE '$DISKIMAGE'"
		return 1;
	fi
	discern_vm_binary || return 1
	NIC_TYPE=${NIC_TYPE:-nat}

	discern_foreground || return 1
}

start_pre() {
	checkpath -d --owner root:root --mode 0644 "${PIDFILE%/*}" \
		"${MONITOR%/*}"
}

start() {
	sanity_check || return 1

	local NIC_COMMAND=(	-net "nic,model=${NIC_MODEL:-virtio},macaddr=${MACADDR}" -net )

	if [ "${NIC_TYPE}" = "br" ]; then
		ebegin "creating qtap ${QTAP:-(auto allocating one)}"
		if [ -n "$QTAP" ]; then
			qtap-manipulate create_specific "${QTAP}" -u "${DROP_USER}"
		else
			QTAP=$(qtap-manipulate create -u "${DROP_USER}")
			if [ 0 != $? ]; then
				eerror "failed to create qtap interface"
				return 1
			fi
		fi
		echo "${QTAP}" > ${QTAP_FILE}
		eend $?
		NIC_COMMAND[${#NIC_COMMAND[@]}]="tap,ifname=${QTAP},script=no"
	elif [ "${NIC_TYPE}" = "none" ]; then
		NIC_COMMAND=( -net none )
	else
		NIC_COMMAND[${#NIC_COMMAND[@]}]=user
	fi

	local ss_args=( )
	local vm_args=( -daemonize )

	if [ -n "${ENABLE_SDL}" ]; then
		ss_args[${#ss_args[@]}]=--env
		ss_args[${#ss_args[@]}]="DISPLAY=${ENABLE_SDL}"
		ss_args[${#ss_args[@]}]=--env
		local user_home=`getent passwd ${DROP_USER:-root} | cut -d: -f6`
		ss_args[${#ss_args[@]}]="XAUTHORITY=$user_home/.Xauthority"
		vm_args[${#vm_args[@]}]=-display
		vm_args[${#vm_args[@]}]=sdl
	elif [ -n "$VNC" ]; then
		vm_args[${#vm_args[@]}]=-display
		vm_args[${#vm_args[@]}]="vnc=${VNC}"
	else
		vm_args[${#vm_args[@]}]=-display
		vm_args[${#vm_args[@]}]=none
	fi

	ebegin "Starting ${VM_BINARY##*/} for ${VMNAME} ${FOREGROUND:+at ${FOREGROUND}}"
	set -- start-stop-daemon \
		--start "${VM_BINARY}" \
		--pidfile ${PIDFILE} \
		"${ss_args[@]}" \
		-- \
		"${vm_args[@]}" \
		-pidfile ${PIDFILE} -monitor unix:${MONITOR},server,nowait \
		-runas ${DROP_USER} -name ${VMNAME} \
		-drive file="${DISKIMAGE//,/,,}",if=${DRIVE_MODEL:-virtio},cache=${DRIVE_CACHE:-none} \
		"${NIC_COMMAND[@]}" \
		${DISABLE_KVM:---enable-kvm}  \
		${MEMORY:+-m ${MEMORY}} ${SMP:+-smp ${SMP}} ${OTHER_ARGS}
	einfo "invoking ${@}"
	"${@}"
	ret=$?
	if [ "0" != "${ret}" -a -n "${QTAP}" ]; then
		qtap-manipulate destroy ${QTAP}
	fi

	eend ${ret}
}

reboot() {
	if [ ${VMNAME} = ${SVCNAME} ]; then
		eerror "You have to create an init script for each vm:"
		eerror " ln -s vm /etc/init.d/vm.vmname"
		return 1
	fi

	ebegin "Rebooting ${VMNAME}"
	send_command system_reset
	eend $?
}

stop() {
	sanity_check || return 1

	ebegin "Powering off ${VMNAME}"
	send_command system_powerdown
	eend $?

	ebegin "waiting up to ${TIMEOUT:-60} seconds for it to die"
	local pid
	[ -s "${PIDFILE}" ] && pid=$(cat "${PIDFILE}")
	if [ -z "$pid" ]; then
		eerror "Couldn't find stored pid at '$PIDFILE'; user will have to manually kill kvm"
		eerror "Will attempt to destroy qtap despite."
		eend 1
	else
		local ret=1
		for x in $(seq 0 ${TIMEOUT:-60}); do
			if kill -0 "${pid}" > /dev/null 2>&1; then
				sleep 1s
				continue
			fi
			ret=0
			break
		done
		eend $ret
	fi

	ebegin "Stopping ${VM_BINARY##*/} for ${VMNAME}"
	if kill -0 "${pid}" > /dev/null 2>&1; then
		start-stop-daemon --stop "${VM_BINARY}" \
			--user "${DROP_USER}" \
			--pidfile "${PIDFILE}" \
			--quiet
		eend $?
	else
		eend 0  # no need to kill process if it is dead :P
	fi
	local qtap
	[ -s "${QTAP_FILE}" ] && qtap=$(cat "${QTAP_FILE}")
	if [ -n "$qtap" ]; then
		ebegin "destroying qtap ${qtap}"
		qtap-manipulate destroy ${qtap}
		eend $?
	fi
}