systemd/extras/path_id

#!/bin/sh

# provide the shortest possible unique hardware path to a block device
# for the udev persistent disk device naming scheme
#
# Copyright (C) 2005 SUSE Linux Products GmbH
# Author:
#	Hannes Reinecke <hare@suse.de>
#
#	This program is free software; you can redistribute it and/or modify it
#	under the terms of the GNU General Public License as published by the
#	Free Software Foundation version 2 of the License.
#
# to be called from a udev rule to return the name for a symlink
#	DEVPATH=/block/sda/sda3 path_id
#	path_id <devpath>

# examples for all block devices on a system:
#	for i in `find /sys/class/block`; do DEVPATH="`echo $i | sed -e 's@^/sys\|/dev@@g'`"; path_id; done

# SCSI cdrom
# /class/block/sr0 -> /devices/pci0002:30/0002:30:0c.0/host0/target0:0:0/0:0:1:0
# pci-0002:30:0c.0-scsi-0:0:1:0
#
# SCSI disk
# /class/block/sda -> /devices/pci0002:30/0002:30:0c.0/host0/target0:0:0/0:0:4:0
# pci-0002:30:0c.0-scsi-0:0:4:0
#
# SATA disk, 4 channels per controller
# /class/block/sda -> /devices/pci0001:00/0001:00:07.0/0001:05:0c.0/host0/target0:0:0/0:0:0:0
# pci-0001:05:0c.0-scsi-0:0:0:0
#
# IDE disk
# /class/block/hda -> /devices/pci0002:02/0002:02:0d.0/ide0/0.0
# pci-0002:02:0d.0-ide-0.0
#
# IDE cdrom on a Mac ASIC:
# /class/block/hdc -> /devices/pci0001:01/0001:01:17.0/0.80000000:mac-io/0.00020000:ata-3/ide1/1.0
# mac-io_ata-3_master
#
# IDE cdrom on a Mac ASIC, with ide-scsi:
# /class/block/sr0 -> /devices/pci0001:01/0001:01:17.0/0.80000000:mac-io/0.0001f000:ata-4/ide0/0.1/host2/target2:0:0/2:0:0:0
# mac-io_ata-4_slave

# USB CDrom drive without 'serial' number:
# reusing 'product' and 'manufacturer' string, if available
# /class/block/sr0 -> /devices/pci0001:00/0001:00:04.0/0001:02:0b.0/usb4/4-2/4-2:1.0/host4/4:0:0:0
# usb-storage-odd-Freecom-USIDERev930:0:0:0

# devices may have several interfaces on one PCI device, like IDE:
# pci-0001:00:04.0_ide1-master
# pci-0001:00:04.0_ide2-master
# pci-0001:00:04.0_ide2-slave
# they are marked as ports, it is expected that the driver shows
# ide1 even if there is nothing connected to either master or slave
# interface
#
# match order is important.
# first IDE to find ide-scsi devices, then SCSI
# first usb-storage, then firewire sbp2, then the rest

SYSFS=/sys
RESULT=1
TYPE=
OPWD="`pwd`"
full_sysfs_path=
full_sysfs_device_path=

if [ -z "$DEVPATH" -a -z "$1" ] ; then
    exit 1
fi

if [ -z "$DEVPATH" ] ; then
    case "$1" in
	$SYSFS/*)
	    DEVPATH="${1#$SYSFS}"
	    ;;
	*)
	    DEVPATH=$1
	    ;;
    esac
fi

if [ ! -e $SYSFS$DEVPATH/dev ] ; then
    exit 1
fi

case "$DEVPATH" in
    /devices/*)
	cd "$SYSFS$DEVPATH/subsystem";
	TYPE="`pwd -P`"
	cd "$OPWD"
	TYPE="${TYPE##*/}"
	;;
    /class/*)
	TYPE="${DEVPATH#/class/}"
	TYPE="${TYPE%%/*}"
	;;
    /block/*)
	TYPE=block
	;;
    *)
	exit 1
	;;
esac

get_port () {
    local type offset port
    type=$1
    offset=$2
    for i in $type[0-9]* ; do
	: i $i
	port="${i#$type}"
	if [ "$port" -lt "$offset" ] ; then offset=$port ; fi
    done
    if [ "$port" != "0" ] ; then
	echo $(($2 - $offset))
    fi
}

handle_block_ide () {
: handle_block_ide $*
	local DEV=$1
	local port idedev idecontroller
	# IDE
	: DEV $DEV
	d=$DEV
	case "$DEV" in
	# remove ide-scsi part, leave only channel info
		*/ide[0-9]*/host[0-9]*)
		while [ ! -z "$d" ] ; do
			case "$d" in
				*/host[0-9]*)
				d="${d%/*}"
				continue
				;;
				*)
				break
				;;
			esac
		done
		;;
	esac
	idedev=$d
	while [ ! -z "$d" ] ; do
		case "$d" in
			*/ide[0-9]*)
			port="${d##*/}"
			d="${d%/*}"
			continue
			;;
			*)
			break
			;;
		esac
	done
	idecontroller=$d
	# port info if the controller has more than one interface
	port="${port#ide}"
	: port $port d $d
	: idedev $idedev kernel_port $port
	case "${idedev##*.}" in
		 0)
		 channel=0
		 ;;
		 1)
		 channel=1
		 ;;
		 *)
		 echo "Error: $idedev is neither master or slave" >&2
	esac
	case "$d" in
		*:mac-io/*)
		: mac-io: $d
		d="`echo $d | sed -e 's@^.*:mac-io[^:]\+:\([^/]\+\).*@mac-io_\1@'`"
		;;
		/sys/devices)
		# PCMCIA devices
		ifname=${full_sysfs_path##*/}
		set -- `sed -n "/$ifname/p" /var/lib/pcmcia/stab`
		d="pcmcia-$1"
		;;
		*)
		d="pci-${d##*/}"
		# d="`echo $d | sed -e 's@^.*/\([^/]\{1,\}\)/.@pci-\1@'`"
		;;
	esac

	cd $idecontroller
	port="`get_port ide $port`"
	cd "$OPWD"
	:  hardware_port $port
	if [ -z "$port" ] ; then
		d="${d}-ide-0:$channel"
	else
		d="${d}-ide-${port}:$channel"
	fi
	RESULT=0
}

handle_block_scsi () {
: handle_block_scsi $*
	local DEV=$1
	local cil controller_port controller_dev
	# SCSI device
	cil="${DEV##*/}"
	cil="${cil#*:}"
	controller_dev=$DEV
	while [ ! -z "$controller_dev" ] ; do
		case "$controller_dev" in
			*/host[0-9]*)
			controller_port=$controller_dev
			controller_dev="${controller_dev%/*}"
			;;
			*) break ;;
		esac
	done
	: controller_dev $controller_dev
	: controller_port $controller_port
	# a host controller may have more than one interface/port
	controller_port="${controller_port##*/}"
	controller_port="${controller_port##host}"
	#
	case "$controller_dev" in
		# grand central, old powermacs
		*:gc/*)
		adapter="`echo $controller_dev |  sed -e 's@/[^/]\{1,\}$@@;s@^.*/@@;s@^.*:@@'`"
		bus="gc"
		;;
		# PARISC devices
		*parisc*)
		adapter="${controler_dev##*/}"
		bus=parisc;
		;;
		*)
		adapter="${controller_dev##*/}"
		bus="pci"
		;;
	esac
	cd "$controller_dev"
	controller_port="`get_port host $controller_port`"
	cd "$OPWD"
	d="$bus-$adapter"
	if [ -z "$controller_port" ] ; then
		controller_port=0
	fi
	d="${d}-scsi-${controller_port}:${cil}"
	RESULT=0
}

handle_block_fc () {
: handle_block_fc $*
	local DEV=$1
	local cil controller_port controller_dev
	# SCSI-FC device
	fc_tgt_hcil="${DEV##*/}"
	fc_tgt_lun="${fc_tgt_hcil##*:}"
	fc_tgt_path="${DEV%/*}"
	fc_tgt_num="${fc_tgt_path##*/}"
	fc_tgt_dev="${fc_tgt_path}/fc_transport:${fc_tgt_num}"
	if [ -e "$fc_tgt_dev/port_name" ]; then
	    read wwpn < $fc_tgt_dev/port_name
	fi
	if [ -z "$wwpn" ] ; then
	    : no WWPN
	    RESULT=1
	    return
	fi
	# Linux currently knows about 32bit luns
	tmp_lun3=$(printf "%04x" $(($fc_tgt_lun & 0xFFFF)))
	tmp_lun2=$(printf "%04x" $(( ($fc_tgt_lun >> 16) & 0xFFFF)))
	tmp_lun1="0000"
	tmp_lun0="0000"

	if (($fc_tgt_lun == 0)) ; then
	    lun="0x0000000000000000"
	else
	    lun="0x${tmp_lun3}${tmp_lun2}${tmp_lun1}${tmp_lun0}"
	fi
	controller_dev="${fc_tgt_path%/host[0-9]*}"
	adapter="${controller_dev##*/}"
	bus="pci"
	d="$bus-$adapter"
	if [ -z "$controller_port" ] ; then
		controller_port=0
	fi
	d="${d}-fc-${wwpn}:${lun}"
	RESULT=0
}

handle_block_usb_storage () {
: handle_block_usb_storage $*
	local DEV=$1
	cil="${DEV##*/}"
	cil="${cil#*:}"
	controller_dev=$DEV
	while [ ! -z "$controller_dev" ] ; do
		case "$controller_dev" in
			*/host[0-9]*)
			controller_dev="${controller_dev%/*}"
			;;
			*) break ;;
		esac
	done
	: controller_dev $controller_dev
	#
	# usb-storage devs have a serial number, hopefully unique
	serial=
	if [ -f $controller_dev/../serial ] ; then
		serial="`sed -e 's@^[ -]\{1,\}\|[ -]\{1,\}$@@g;s@[^abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789-]@@g' < $controller_dev/../serial`"
		: serial XXX_${serial}_XXX
		d="usb-$serial"
		serial="`echo $serial | sed -e 's@[ 0]\{1,\}@@g'`"
	fi
	if [ -z "$serial" ] ; then
		# no serial, broken device
		# has eventually binary junk in vpd
		identifier=
		if [ -f $controller_dev/../product ] ; then
		product="`sed -e 's@^[ -]\{1,\}\|[ -]\{1,\}$@@g;s@[^abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789-]@@g' < $controller_dev/../product`"
		fi
		if [ -f $controller_dev/../manufacturer ] ; then
		manufacturer="`sed -e 's@^[ -]\{1,\}\|[ -]\{1,\}$@@g;s@[^abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789-]@@g' < $controller_dev/../manufacturer`"
		fi
		if [ -z "$product" -o -z "$manufacturer" ] ; then
			read idvendor < $controller_dev/../idVendor
			read idproduct < $controller_dev/../idProduct
			identifier="0x${idvendor}-0x${idproduct}"
		else
			identifier="${manufacturer}-${product}"
		fi
		d="usb-${identifier}"
	fi
	d="$d:$cil"
	RESULT=0
}

handle_block () {
    full_sysfs_path="$SYSFS$DEVPATH"
    if [ -L $full_sysfs_path/subsystem ]; then
	# new sysfs block layout
	full_sysfs_path="${full_sysfs_path%/*}"
	cd "$full_sysfs_path/subsystem";
	subsys="`pwd -P`"
	cd "$OPWD"
	subsys="${subsys##*/}"
	if [ "$subsys" == "block" ]; then
	    # parent is "block", it's a partition, move one up
	    full_sysfs_path="${full_sysfs_path%/*}"
	fi
	cd $full_sysfs_path
    else
	# old sysfs block layout
	if [ ! -L $full_sysfs_path/device ] ; then
	    if [ -f $full_sysfs_path/range ] ; then return ; fi
	    full_sysfs_path="${full_sysfs_path%/*}"
	    : full_sysfs_path "$full_sysfs_path"
	    if [ ! -L $full_sysfs_path/device -o ! -f $full_sysfs_path/dev ] ; then
		return
	    fi
        fi
	cd $full_sysfs_path/device
    fi
    full_sysfs_device_path="`pwd -P`"
    cd "$OPWD"
    D=$full_sysfs_device_path
    case "$D" in
	*/ide[0-9]/[0-9].[0-9]*|*/ide[0-9][0-9]/[0-9][0-9].[0-9]*)
	handle_block_ide "$D"
	;;
	*/usb[0-9]*/[0-9]*/host[0-9]*/[0-9]*:[0-9]*:[0-9]*:[0-9]*)
	handle_block_usb_storage "$D"
	;;
	*/css0/*)
	if [ -r $full_sysfs_device_path/wwpn ]; then
	    read wwpn < $full_sysfs_device_path/wwpn
	fi
	if [ -r $full_sysfs_device_path/fcp_lun ]; then
	    read lun < $full_sysfs_device_path/fcp_lun
	fi
	if [ -r $full_sysfs_device_path/hba_id ]; then
	    read bus_id < $full_sysfs_device_path/hba_id
	fi
	if [ "$bus_id" -a "$wwpn" -a "$lun" ]; then
	    # S/390 zfcp adapter
	    d="ccw-$bus_id-zfcp-$wwpn:$lun"
	    RESULT=0
	else
	    # DASD devices
	    bus="ccw"
	    adapter=${D##*/}
	    d="$bus-$adapter"
	    RESULT=0
	fi
	;;
	*/rport-[0-9]*:[0-9]*-[0-9]*/*)
	handle_block_fc "$D"
	;;
	*/host[0-9]*/[0-9]*:[0-9]*:[0-9]*:[0-9]*)
	# check for ieee1394 sbp2 
	if test -f $D/ieee1394_id ; then
	    read ieee1394_id < $D/ieee1394_id
	    d="`echo ieee1394-${ieee1394_id} | sed -e 's@:@-@g'`"
	    RESULT=0
	else
	    handle_block_scsi "$D"
	fi
	;;
	*)
	: not handled
	RESULT=1
	return
	;;
    esac
    echo "ID_PATH=$d"
}

case "$TYPE" in
	block)
	handle_block
	;;
	*)
	RESULT=1
	;;
esac
exit $RESULT