#! /bin/sh
set -e
TYPE="$1"

case $TYPE in
    maybe-floppy)
	logger -t list-devices "deprecated parameter maybe-floppy"
	TYPE=floppy
	;;
    cd|disk|partition|floppy|maybe-usb-floppy|usb-partition|mmc-partition) ;;
    *)
	echo "Usage: $0 cd|disk|partition|floppy|maybe-usb-floppy|usb-partition|mmc-partition" >&2
	exit 2
	;;
esac

if [ ! -d /sys/block ]; then
	exit 0
fi
if type udevadm >/dev/null 2>&1; then
	device_info () {
		udevadm info -q "$1" -p "$2" 2>/dev/null
	}
elif type udevinfo >/dev/null 2>&1; then
	device_info () {
		udevinfo -q "$1" -p "$2" 2>/dev/null
	}
else
	exit 0
fi

device_name () {
	local name
	if ! name="$(device_info name "$1")"; then
		name="$(printf %s "${1##*/}" | \
			sed 's,!,/,g')"
	fi
	echo "/dev/$name"
}

is_lvm() {
	grep -qs ^LVM- "$1/dm/uuid"
}

is_sataraid () {
	grep -qs ^DMRAID- "$1/dm/uuid"
}

is_sataraid_partition () {
	# dmraid partitions are always slaved to another dm device
	for slave in "$1"/slaves/dm-*; do
		if [ -e "$slave" ]; then
			return 0
		fi
	done
	return 1
}

if type dmraid >/dev/null 2>&1; then
	raiddevs="$(dmraid -r -c || true)"
else
	raiddevs=
fi
if type pvs >/dev/null 2>&1; then
	lvm_pvs="$(pvs -S pv_in_use=1 -o pv_name --no-headings || true)"
else
	lvm_pvs=
fi


# cloned-and-hacked from partman-base/init.d/parted
part_of_sataraid () {
	local raiddev
	for raiddev in $raiddevs; do
		if [ "$(readlink -f "$raiddev")" = "$1" ]; then
			return 0
		fi
	done
	return 1
}

part_of_lvmvg () {
	local pvdev
	for pvdev in $lvm_pvs; do
		if [ "$pvdev" = "$1" ]; then
			return 0
		fi
	done
	return 1
}

syspaths=
scan_partition=false
case $TYPE in
    partition)
	for x in /sys/block/*/*[0-9]; do
		[ -d "$x" ] || continue
		name="$(device_name "$x")"
		if part_of_lvmvg "$name"; then
			continue
		fi
		syspaths="${syspaths:+$syspaths }$x"
	done
	for x in /sys/block/dm-*; do
		[ -d "$x" ] || continue
		if is_lvm "$x"; then
			: # Keep LVM logical volumes
		elif is_sataraid "$x" && is_sataraid_partition "$x"; then
			: # Keep dmraid partitions
		else
			continue  # Skip unknown entries
		fi
		syspaths="${syspaths:+$syspaths }$x"
	done
	TYPE=disk
	# Also allow misdetected USB devices
	scan_partition=:
	;;
    usb-partition|mmc-partition)
	for x in /sys/block/*/*; do
		[ -d "$x" ] || continue
		syspaths="${syspaths:+$syspaths }$x"
	done
	;;
    *)
	for x in /sys/block/*; do
		[ -d "$x" ] || continue
		case $x in
		    /sys/block/dm-*)
			if is_sataraid "$x" && is_sataraid_partition "$x"; then
				continue
			fi
			if is_lvm "$x"; then
				continue
			fi
			;;
		    *)
			name="$(device_name "$x")"
			if part_of_sataraid "$name"; then
				continue
			fi
			if part_of_lvmvg "$name"; then
				continue
			fi
			;;
		esac
		syspaths="${syspaths:+$syspaths }$x"
	done
	;;
esac
for x in $syspaths; do
	devpath="${x#/sys}"
	match=false
	case $TYPE in
	    floppy)
		# TODO ugly special case for non-IDE floppies
		case $devpath in
		    /block/fd[0-9]*)
			match=:
			;;
		esac
		;;
	esac
	if ! $match && [ "$TYPE" = cd ]; then
		if device_info env "$devpath" | grep -q '^ID_CDROM='; then
			match=:
		fi
	fi
	if ! $match; then
		if device_info env "$devpath" | grep -q "^ID_TYPE=$TYPE"; then
			match=:
		fi
	fi
	if ! $match && [ "$TYPE" = disk ]; then
		case $devpath in
		    /block/cciss\!*|/block/ida\!*|/block/rd\!*|/block/nvme*|/block/mmcblk*|/block/vd[a-z]*|/block/xvd[a-z]*)
			match=:
			;;
		    /block/dm-*)
			# for now, we only understand dmraid and LVM
			if is_sataraid "/sys$devpath"; then
				match=:
			fi
			if is_lvm "/sys$devpath"; then
				match=:
			fi
			;;
		esac
	fi
	# Some USB sticks and CD drives are misdetected as floppy
	# This allows to scan for those
	if ! $match && ( $scan_partition || [ "$TYPE" = maybe-usb-floppy ] ); then
		if device_info env "$devpath" | grep -q '^ID_BUS=usb' && \
		   device_info env "$devpath" | grep -q '^ID_TYPE=floppy'; then
			match=:
		fi
	fi
	# Disk partitions, but only on USB drives
	if ! $match && [ "$TYPE" = usb-partition ]; then
		if device_info env "$devpath" | grep -q '^ID_BUS=usb' && \
		   device_info env "$devpath" | grep -q '^ID_TYPE=disk'; then
			match=:
		fi
	fi
	# Disk partitions, but only on (non-USB) MMC devices
	if ! $match && [ "$TYPE" = mmc-partition ]; then
		if device_info env "$devpath" | egrep -q '^ID_PATH=(platform-mmc|platform-orion-ehci|platform-mxsdhci|platform-omap)'; then
			match=:
		fi
	fi
	if $match && ! device_info env "$devpath" | egrep -q '^ID_PART_ENTRY_TYPE=0x(5|f|85)$'; then
		device_name "/sys$devpath"
	fi
done
