#! /bin/sh
#
# /usr/sbin/dahdi_span_types
#
# This script can be used both from udev and
# from the command line to manage PRI spans
# type (E1/T1/J1).
#
# Span types can be set only *BEFORE* span are assigned.
#
# It uses a configuration file: $DAHDICONFDIR/span-types.conf
# (default DAHDICONFDIR=/etc/dahdi)
# (the format is documented inside that file)
#
# The first argument is an action:
#   "set"        - actually write the setting to the driver
#   "list"       - human-readable list of E1/T1/J1 types
#   "dumpconfig" - dump current assignments in a /etc/dahdi/span-types.conf
#                  compatible format
#
# Without further arguments, it operates on all existing spans
# With one or more sysfs dahdi_devices it is limited to those.
#
# We may use alternative "keys" for device matching:
# * Available keys:
#   - "hwid"       - Hardware id attribute from sysfs
#   - "@location"  - Location attribute from sysfs (embeded inside '<>')
#   - "/devpath"   - The sysfs absolute devpath
#
# * During "dumpconfig", for each device we take the first available key:
#   - The preference is: "hwid" or else "@location" or else "/devpath"
#   - This can be overriden via the SPAN_ASSIGNMENTS_KEY environment variable
#     or the '{-k|--key} key' command line option.
#
# Command line options:
#  - The '-h|--help' show a usage message.
#  - The '-k <key>|--key <key>' overrides the SPAN_ASSIGNMENTS_KEY environment
#    variable.
#
# Examples:
#    dahdi_span_types list
#    dahdi_span_types set	     # all devices
#    dahdi_span_types set /sys/bus/dahdi_devices/devices/astribanks:xbus-00
#    dahdi_span_types -k location dumpconfig
#


devbase='/sys/bus/dahdi_devices/devices'
DAHDICONFDIR="${DAHDICONFDIR:-/etc/dahdi}"
DAHDISPANTYPESCONF="${DAHDISPANTYPESCONF:-"${DAHDICONFDIR}/span-types.conf"}"
SPAN_ASSIGNMENTS_KEY=${SPAN_ASSIGNMENTS_KEY:-hwid}

usage() {
	echo >&2 "Usage: $0 [options] action [devpath ...]"
	echo >&2 "       action:"
	echo >&2 "         set        - set spans to E1/T1 according to configuration"
	echo >&2 "         list       - human-readable list of all spans"
	echo >&2 "         dumpconfig - dump current state as new configuration"
	echo >&2 ""
	echo >&2 "       options:"
	echo >&2 "         -h|--help      - Show this help"
	echo >&2 "         -k|--key <k>   - Override prefered key during dumpconfig action"
	exit 1
}

# Parse command line options
TEMP=`getopt -o hk: --long help,key: -n "$0" -- "$@"`
if [ $? != 0 ]; then
	echo >&2 "Bad options"
	usage
fi

# Note the quotes around `$TEMP': they are essential!
eval set -- "$TEMP"

while true ; do
	case "$1" in
	-h|--help)
		usage
		;;
	-k|--key)
		SPAN_ASSIGNMENTS_KEY="$2"
		shift
		shift
		;;
	--)
		shift
		break
		;;
	*)
		echo "Internal error!"
		exit 1
		;;
	esac
done

if [ "$#" -eq 0 ]; then
	echo >&2 "Missing action argument"
	usage
fi
action="$1"
shift

# Validate SPAN_ASSIGNMENTS_KEY
case "$SPAN_ASSIGNMENTS_KEY" in
hwid|location|devpath)
	;;
*)
	echo >&2 "Bad SPAN_ASSIGNMENTS_KEY='$SPAN_ASSIGNMENTS_KEY' (should be: hwid|location|devpath)"
	usage
	;;
esac

if [ ! -d "$devbase" ]; then
	echo >&2 "$0: Missing '$devbase' (DAHDI driver unloaded?)"
	exit 1
fi

# Use given devices or otherwise, all existing devices
if [ "$#" -gt 0 ]; then
	DEVICES="$@"
else
	DEVICES=`ls -d $devbase/* 2>/dev/null`
fi

# Beware of special characters in attributes
attr_clean() {
	cat "$1" | tr -d '\n' | tr '!' '/' | tr -c 'a-zA-Z0-9/:.-' '_'
}

show_spantypes() {
	echo "# PRI span types (E1/T1/J1)"
	for device in $DEVICES
	do
		devpath=`cd "$device" && pwd -P`
		location='@'`attr_clean "$device/location"`
		hardware_id=`attr_clean "$device/hardware_id"`
		cat "$device/spantype" | while read st; do
			case "$st" in
			*:[ETJ]1)
				printf "%-10s %-20s %s\n" \
					"$st" "[$hardware_id]" "$location"
				;;
			esac
		done | sort -n
	done
}

dump_config() {
	echo '#'
	echo "# Autogenerated by $0 on `date`"
	echo "# Map PRI DAHDI devices to span types for E1/T1/J1"
	echo ''
	fmt="%-65s %s\n"
	printf "$fmt" '# @location/hardware_id' 'span_type'
	for device in $DEVICES
	do
		devpath=`cd "$device" && pwd -P`
		location=`attr_clean "$device/location"`
		hardware_id=`attr_clean "$device/hardware_id"`
		if [ "$SPAN_ASSIGNMENTS_KEY" = 'hwid' -a "$hardware_id" != '' ]; then
			id="$hardware_id"
		elif [ "$SPAN_ASSIGNMENTS_KEY" = 'location' -a "$location" != '' ]; then
			id="@$location"
		else
			id="$devpath"
		fi
		echo "# Device: [$hardware_id] @$location $devpath"
		cat "$device/spantype" | while read st; do
			case "$st" in
			*:[ETJ]1)
				printf "$fmt" "$id" "$st"
				;;
			*)
				#echo "#    Skipped local span `echo $st | sed 's/:/ -- /'`"
				;;
			esac
		done | sort -n
		#echo ''
	done
}

# Allow comments and empty lines in config file
filter_conf() {
	sed -e 's/#.*//' -e '/^[ \t]*$/d' "$DAHDISPANTYPESCONF"
}

conf_spans() {
	hardware_id="$1"
	location="$2"
	devpath="$3"
	filter_conf | (
		# Collect device spans
		# in a subshell, so $SPANS is not lost
		SPANS=''
		while read id spans; do
			# GLOBBING
			case "$location" in
			$id)
				#echo >&2 "match($id): $spans"
				SPANS="$SPANS $spans"
				;;
			esac
			case "$hardware_id" in
			$id)
				#echo >&2 "match([$id]): $spans"
				SPANS="$SPANS $spans"
				;;
			esac
			case "$devpath" in
			$id)
				#echo >&2 "match([$id]): $spans"
				SPANS="$SPANS $spans"
				;;
			esac
		done
		echo "$SPANS"
	)
}

device_set_spantype() {
	device="$1"
	attr_file="$device/spantype"
	devpath=`cd "$device" && pwd -P`
	location='@'`attr_clean "$device/location"`
	hardware_id=`attr_clean "$device/hardware_id"`
	spanspecs=`conf_spans "$hardware_id" "$location" "$devpath"`
	#echo >&2 "MATCHED($device): $spanspecs"
	cut -d: -f1 "$attr_file" | while read spanno; do
			for sp in $spanspecs
			do
				s=`echo "$sp" | cut -d: -f1`
				v=`echo "$sp" | cut -d: -f2`
				case "$spanno" in
				$s)
					#echo >&2 "conf($attr_file): $spanno:$v"
					echo "$spanno:$v" > "$attr_file"
					;;
				esac
			done
		done
}

set_spantypes() {
	if [ ! -f "$DAHDISPANTYPESCONF" ]; then
		echo >&2 "$0: Missing configuration '$DAHDISPANTYPESCONF'"
		exit 1
	fi
	for device in $DEVICES
	do
		device_set_spantype "$device"
	done
}

case "$action" in
list)
	show_spantypes
	;;
dumpconfig)
	dump_config
	;;
set)
	set_spantypes
	;;
*)
	usage
	;;
esac