#!/bin/sh
#===============================================================================
# scstlun, (c) 2013 Navixia SA
#-------------------------------------------------------------------------------
# $Id$
#-------------------------------------------------------------------------------
# This resource agent will configure an iSCSI target and export a single LUN
# via that target. The iSCSI implementation being used is SCST, and the RA
# requires the SYSFS management interface to be available (not compatible
# with the PROCFS management interface).
#
# OCF instance parameters
#	OCF_RESKEY_iqn
#	OCF_RESKEY_path
#	OCF_RESKEY_iomode
#	OCF_RESKEY_t10
#-------------------------------------------------------------------------------

#===============================================================================
# Initialization
#-------------------------------------------------------------------------------
: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

#===============================================================================
# Defaults
#-------------------------------------------------------------------------------
OCF_RESKEY_iomode_default="fileio"
: ${OCF_RESKEY_iomode=${OCF_RESKEY_iomode_default}}

#===============================================================================
# Configuration
#-------------------------------------------------------------------------------
SCST_base="/sys/kernel/scst_tgt"
ISCSI_base="${SCST_base}/targets/iscsi"

#===============================================================================
# Meta-data
#-------------------------------------------------------------------------------
scstlun_meta_data() {
	cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="scstlun" version="0.2">
  <version>0.2</version>
  <longdesc lang="en">
Configures an iSCSI target and export a single LUN (0) via that target. The iSCSI
implementation being used is SCST, and the RA requires the SYSFS management
interface to be available (not compatible with the PROCFS management interface).
  </longdesc>
  <shortdesc lang="en">Exports a device via an SCST iSCSI Target/Lun pair</shortdesc>
  <parameters>
    <parameter name="iqn" required="1" unique="1">
    <longdesc lang="en">
    The iSCSI Qualified Name (IQN) of the target that will be enabled.
    </longdesc>
    <shortdesc lang="en">iSCSI target IQN</shortdesc>
    <content type="string" />
    </parameter>
    
    <parameter name="path" required="1">
    <longdesc lang="en">
    The path to the block device exposed as LUN0.
    </longdesc>
    <shortdesc lang="en">Block device path that will be exposed</shortdesc>
    <content type="string" />
    </parameter>
    
    <parameter name="iomode" required="0">
    <longdesc lang="en">
    SCST IO mode to be used (either fileio or blockio). Defaults to fileio
    </longdesc>
    <shortdesc lang="en">IO mode (either fileio or blockio). Defaults to fileio</shortdesc>
    <content type="string" default="${OCF_RESKEY_iomode_default}" />
    </parameter>
    
    <parameter name="t10" unique="1">
    <longdesc lang="en">
    Define the SCSI T10 device ID
    </longdesc>
    <shortdesc lang="en">T10 device ID</shortdesc>
    <content type="string" />
    </parameter>
  </parameters>

  <actions>
    <action name="start"		timeout="10" />
    <action name="stop"			timeout="60" />
    <action name="monitor"		timeout="10" interval="10" depth="0" />
    <action name="meta-data"	timeout="5" />
    <action name="validate-all"	timeout="10" />
  </actions>
</resource-agent>
END
}

#===============================================================================
# usage
#-------------------------------------------------------------------------------
scstlun_usage() {
	cat <<END
usage: $0 {start|stop|monitor|validate-all|meta-data}

Expects to have a fully populated OCF RA-compliant environment set.
END
}

#===============================================================================
# start
#-------------------------------------------------------------------------------
scstlun_start() {
	ocf_log debug "start: entering start action"

	if scstlun_monitor; then
		ocf_log info "Resource is already running"
		return $OCF_SUCCESS
	fi

	ocf_log debug "start: checking if target exists"
	if [ ! -e "${ISCSI_base}/${OCF_RESKEY_iqn}" ]; then
		ocf_log err "target ${OCF_RESKEY_iqn} does not exist"
		return $OCF_ERR_GENERIC
	fi

	# Build SCST device name from path
	devname=`basename ${OCF_RESKEY_path}`

	# Configure the backend device
	ocf_log debug "start: configuring ${OCF_RESKEY_iomode} device ${devname} (path=${OCF_RESKEY_path})"
	echo "add_device ${devname} filename=${OCF_RESKEY_path}; nv_cache=1" >${SCST_base}/handlers/vdisk_${OCF_RESKEY_iomode}/mgmt
	if [ $? -ne 0 ]; then
		ocf_log err "start: FAILED to configure backend device ${devname}"
		return $OCF_ERR_GENERIC
	fi

	# Add backend device to target
	ocf_log debug "start: adding device ${devname} as LUN 0 to target ${OCF_RESKEY_iqn}"
	echo "add ${devname} 0" >${ISCSI_base}/${OCF_RESKEY_iqn}/luns/mgmt
	if [ $? -ne 0 ]; then
		ocf_log err "start: FAILED to add device ${devname} as LUN 0 to target ${OCF_RESKEY_iqn}"
		return $OCF_ERR_GENERIC
	fi

	# If present, configure T10 device ID
	if [ -n "${OCF_RESKEY_t10}" ]; then
		ocf_log debug "start: change t10 id for device ${devname} on target ${OCF_RESKEY_iqn} to ${OCF_RESKEY_t10}"
		echo "${OCF_RESKEY_t10}" >${ISCSI_base}/${OCF_RESKEY_iqn}/luns/0/device/t10_dev_id
		if [ $? -ne 0 ]; then
			ocf_log err "start: FAILED to change t10 id for device ${devname} on target ${OCF_RESKEY_iqn} to ${OCF_RESKEY_t10}"
			return $OCF_ERR_GENERIC
		fi

		ocf_log debug "start: change usn id for device ${devname} on target ${OCF_RESKEY_iqn} to ${OCF_RESKEY_t10}"
		echo "${OCF_RESKEY_t10}" >${ISCSI_base}/${OCF_RESKEY_iqn}/luns/0/device/usn
		if [ $? -ne 0 ]; then
			ocf_log err "start: FAILED to change usn id for device ${devname} on target ${OCF_RESKEY_iqn} to ${OCF_RESKEY_t10}"
			return $OCF_ERR_GENERIC
		fi
	fi

	# Finally, enable the target
	ocf_log debug "start: enabling target ${OCF_RESKEY_iqn}"
	echo 1 >${ISCSI_base}/${OCF_RESKEY_iqn}/enabled
	if [ $? -ne 0 ]; then
		ocf_log err "start: FAILED to enable target ${OCF_RESKEY_iqn}"
		return $OCF_ERR_GENERIC
	fi

	while ! scstlun_monitor; do
		ocf_log debug "Resource has not started yet, waiting"
		sleep 1
	done

	return $OCF_SUCCESS
}

#===============================================================================
# stop
#-------------------------------------------------------------------------------
scstlun_stop() {
	ocf_log debug "stop: entering stop action"

	scstlun_monitor
	if [ $? != $OCF_SUCCESS ]; then
		return $OCF_SUCCESS
	fi

	# Build SCST device name from path
	devname=`basename ${OCF_RESKEY_path}`

	# Disable the target
	ocf_log debug "stop: disabling target ${OCF_RESKEY_iqn}"
	echo 0 >${ISCSI_base}/${OCF_RESKEY_iqn}/enabled
	if [ $? -ne 0 ]; then
		ocf_log err "stop: FAILED to disable target ${OCF_RESKEY_iqn}"
		return $OCF_ERR_GENERIC
	fi

	# Close all the existing sessions
	for s in `ls -1 ${ISCSI_base}/${OCF_RESKEY_iqn}/sessions` ; do
		ocf_log debug "stop: disabling session $s on target ${OCF_RESKEY_iqn}"
		echo 1 >${ISCSI_base}/${OCF_RESKEY_iqn}/sessions/$s/force_close
		if [ $? -ne 0 ]; then
			ocf_log err "stop: FAILED to disable session $s on target ${OCF_RESKEY_iqn}"
			return $OCF_ERR_GENERIC
		fi
	done

	# Remove LUN from target
	ocf_log debug "stop: removing LUN 0 from target ${OCF_RESKEY_iqn}"
	echo "del 0" >${ISCSI_base}/${OCF_RESKEY_iqn}/luns/mgmt
	if [ $? -ne 0 ]; then
		ocf_log err "stop: FAILED to remove LUN 0 from target ${OCF_RESKEY_iqn}"
		return $OCF_ERR_GENERIC
	fi

	ocf_log debug "stop: removing device ${devname}"
	echo "del_device ${devname}" >${SCST_base}/handlers/vdisk_${OCF_RESKEY_iomode}/mgmt
	if [ $? -ne 0 ]; then
		ocf_log err "stop: FAILED to remove device ${devname}"
		return $OCF_ERR_GENERIC
	fi

	while scstlun_monitor; do
		ocf_log debug "Resource has not stopped yet, waiting"
		sleep 1
	done

	return $OCF_SUCCESS
}

#===============================================================================
# monitor
#-------------------------------------------------------------------------------
scstlun_monitor() {
	ocf_log debug "monitor: entering monitor action"

	# Build SCST device name from path
	devname=`basename ${OCF_RESKEY_path}`

	ocf_log debug "monitor: checking if ${SCST_base}/handlers/vdisk_${OCF_RESKEY_iomode}/${devname} exists"
	if [ ! -e "${SCST_base}/handlers/vdisk_${OCF_RESKEY_iomode}/${devname}" ]; then
		ocf_log debug "monitor: Device ${devname} not configured"
		return $OCF_NOT_RUNNING
	fi

	# Check if device is mapped to LUN
	ocf_log debug "monitor: checking if ${ISCSI_base}/${OCF_RESKEY_iqn}/luns/0 exists"
	[ -e "${SCST_base}/targets/iscsi/${OCF_RESKEY_iqn}/luns/0" ]
	if [ $? -ne 0 ]; then
		ocf_log debug "monitor: LUN is not configured for target ${OCF_RESKEY_iqn}"
		return $OCF_NOT_RUNNING
	fi

	return $OCF_SUCCESS
}

#===============================================================================
# validate
#-------------------------------------------------------------------------------
scstlun_validate_all() {
	ocf_log debug "validate: entering validate action"

	ocf_log debug "validate: checking if iscsi-scstd is running"
	if [ -z "`pidof iscsi-scstd`" ]; then
		ocf_log err "iscsi-scstd is not running"
		exit $OCF_ERR_GENERIC
	fi

	ocf_log debug "validate: checking if ${SCST_base} exists"
	if [ ! -e "${SCST_base}" ]; then
		ocf_log err "${SCST_base} does not exist"
		exit $OCF_ERR_GENERIC
	fi

	ocf_log debug "validate: checking if ${ISCSI_base} exists"
	if [ ! -e "${ISCSI_base}" ]; then
		ocf_log err "${ISCSI_base} does not exist"
		exit $OCF_ERR_GENERIC
	fi

	ocf_log debug "validate: checking for required variables"
	for var in iqn path; do
		param="OCF_RESKEY_${var}"
		if [ -z "${!param}" ]; then
			ocf_log error "Missing resource parameter \"$var\"!"
			return $OCF_ERR_CONFIGURED
		fi
	done

	ocf_log debug "validate: checking for valid iomode"
	case "${OCF_RESKEY_iomode}" in
		fileio|blockio)		;;
		*)					ocf_log error "Invalid iomode. Must be either fileio or blockio"
							return $OCF_ERR_CONFIGURED
							;;
	esac

	return $OCF_SUCCESS
}

#===============================================================================
# main
#-------------------------------------------------------------------------------
# Make sure meta-data and usage always succeed
case $__OCF_ACTION in
meta-data)      scstlun_meta_data
                exit $OCF_SUCCESS
                ;;
usage|help)     scstlun_usage
                exit $OCF_SUCCESS
                ;;
esac

# Anything other than meta-data and usage must pass validation
scstlun_validate_all || exit $?

# Translate each action into the appropriate function call
case $__OCF_ACTION in
start)			scstlun_start;;
stop)			scstlun_stop;;
monitor)		scstlun_monitor;;
validate-all)	;;
*)				scstlun_usage
				exit $OCF_ERR_UNIMPLEMENTED
				;;
esac
rc=$?

ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION returned $rc"
exit $rc