#!/bin/bash
# SPDX-License-Identifier: MIT
#
# chreipl-fcp-mpath: use multipath information to change FCP IPL target
# (C) Copyright IBM Corp. 2021
#
# Uses the following system-utilities (and shell-builtins):
#   Those necessary for sourced library:
#     - chreipl-fcp-mpath-common.sh

# Find out whether the device in udev event environment variable ${DEVPATH}
# represents the device we want to re-IPL from. We do this by comparing
# Device-Bus-ID/Target-WWPN/LUN of the individual SDEVs to the parameters set
# in `/sys/firmware/reipl/fcp/`.
#
# Makes use of udev event environment variables:
#	DM_UUID
#	SUBSYSTEM
#	DEVPATH

# shellcheck disable=SC2034
declare -gr debug_trace_tag=05iilt
# shellcheck disable=SC1091
source '@chreiplzfcpmp-lib@' || exit 127

firmware_get_ipl_information					|| exit 1

if [[ "${DM_UUID}" == mpath-* ]]; then
	# Assume Multipath Device Mapper Device;
	# e.g.: DEVPATH = /devices/virtual/block/dm-0
	declare sdev

	# depends on `nullglob` from `chreipl-fcp-mpath-common.sh`
	for sdev in /sys/"${DEVPATH}"/slaves/sd*/device; do
		sdev_get_fcp_addressing "${sdev}"		|| continue
		[ "${SDEV_LUN}" = "${IPL_LUN}" ]		|| continue
		[ "${SDEV_WWPN}" = "${IPL_WWPN}" ]		|| continue
		[ "${SDEV_BUSID}" = "${IPL_BUSID}" ]		|| continue

		exit 0
	done
	unset sdev

elif [ "${SUBSYSTEM}" = block ]; then
	# Assume SCSI Disk;
	# e.g.: DEVPATH = /devices/css0/0.0.0014/0.0.1700/host0/rport-0:0-0/target0:0:0/0:0:0:1074806808/block/sds

	sdev_get_fcp_addressing /sys/"${DEVPATH}"/device	|| exit 2
	[ "${SDEV_LUN}" = "${IPL_LUN}" ]			|| exit 3
	[ "${SDEV_WWPN}" = "${IPL_WWPN}" ]			|| exit 4
	[ "${SDEV_BUSID}" = "${IPL_BUSID}" ]			|| exit 5

	exit 0
fi

exit 6