#! /bin/sh
#
# /usr/share/dahdi/span_assignments:
#
# this script can be used both from udev and
# from the command line to assign/unassign and list
# current assignments.
#
# The first argument is an action:
#   "add" to assign (spans which are not already assigned)
#   "remove" to unassign (spans which are not already unassigned)
#   "list" to show all spans (with/without assignments)
#
# Without further arguments, it operates on all existing spans
# With one or more sysfs dahdi_devices it is limited to those.
#
# Examples:
#    span_assignments list
#    span_assignments add	# all
#    span_assignments add /sys/bus/dahdi_devices/devices/astribanks:xbus-00
#    span_assignments remove	# all
#

devbase='/sys/bus/dahdi_devices/devices'
DAHDICONFDIR="${DAHDICONFDIR:-/etc/dahdi}"
pinned_spans_conf="$DAHDICONFDIR/pinned-spans.conf"

usage() {
	echo >&2 "Usage: $0 {add|remove|list} [devpath ...]"
	exit 1
}

if [ "$#" -eq 0 ]; then
	usage
fi
action="$1"
shift

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=`echo $devbase/*`
fi

show_devices() {

	for device in $DEVICES
	do
		hw_id=`cat "$device/hardware_id"`
		location=`cd "$device" && pwd -P | sed 's,/sys/devices/,,'`
		for local_spanno in `cut -d: -f1 "$device/spantype"`
		do
			span=`grep 2>/dev/null -Hw "$local_spanno" "$device/span-"*"/local_spanno" | \
				sed -e 's,/local_spanno:.*,,' -e 's,.*/,,'`
			if [ "$span" != '' ]; then
				spanno=`echo $span | sed 's/^.*-//'`
				name=`cat 2>/dev/null "$device/$span/name"`
				basechan=`cat 2>/dev/null "$device/$span/basechan"`
			else
				spanno='-'
				basechan='-'
			fi
			printf "%-4s %-12s %s\n" "$local_spanno:$spanno:$basechan" "[$hw_id]" "@$location"
		done | sort -n
	done
}

dump_config() {

	for device in $DEVICES
	do
		hw_id=`cat "$device/hardware_id"`
		location=`cd "$device" && pwd -P | sed 's,/sys/devices/,,'`
		if [ "$hw_id" != '' ]; then
			id="$hw_id"
		else
			id="@$location"
		fi
		for local_spanno in `cut -d: -f1 "$device/spantype"`
		do
			span=`grep 2>/dev/null -Hw "$local_spanno" "$device/span-"*"/local_spanno" | \
				sed -e 's,/local_spanno:.*,,' -e 's,.*/,,'`
			if [ "$span" != '' ]; then
				spanno=`echo $span | sed 's/^.*-//'`
				name=`cat 2>/dev/null "$device/$span/name"`
				basechan=`cat 2>/dev/null "$device/$span/basechan"`
			else
				spanno='-'
			fi
			printf "%-30s %s\n" "$id" "$local_spanno:$spanno:$basechan"
		done | sort -n
	done
}

unassign_all_spans() {
	for device in $DEVICES
	do
		find "$device" -follow -maxdepth 1 -name 'span-*' -type d | \
			sort | while read spandir; do
			local_spanno=`cat "$spandir/local_spanno"`
			echo "unassign $device $local_spanno"
			if ! echo "$local_spanno" > "$device/unassign_span"; then
				echo >&2 "$0: failed unassigning '$local_spanno' in '$device'"
			fi
		done
	done
}

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

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

assign_device_spans() {
	device="$1"
	for s in $spanspecs
	do
		local_spanno=`echo "$s" | cut -d: -f1`
		spanno=`echo "$s" | cut -d: -f2`
		span="$device/span-$spanno"
		if [ -d "$span" ]; then
			span_local_spanno=`cat "$span/local_spanno"`
			if [ "$span_local_spanno" != "$local_spanno" ]; then
				echo "WARNING: $span_local_spanno != $local_spanno"
			fi
			echo "$device [$local_spanno] already assigned to $spanno. Skipping..."
			continue
		fi
		echo "assign $device: $s"
		if ! echo "$s" > "$device/assign_span"; then
			echo >&2 "$0: failed assigning '$s' to '$device'"
		fi
	done
}

match_device() {
	device="$1"
	location='@'`cd "$device" && pwd -P | sed 's,/sys/devices/,,'`
	hardware_id=`attr_clean "$device/hardware_id"`
	filter_conf | while read id spanspecs
	do
		# We use case to enable shell-style globbing in configuration
		case "$location" in
		$id)
			#echo "match location($id ~ $location): $spanspecs"
			assign_device_spans "$device"
			;;
		esac
		# We use case to enable shell-style globbing in configuration
		case "$hardware_id" in
		$id)
			#echo "match hardware_id([$id] ~ $hardware_id): $spanspecs"
			assign_device_spans "$device"
			;;
		esac
	done
}

assign_devices() {
	for device in $DEVICES
	do
		match_device "$device"
	done
}

case "$action" in
list)
	show_devices
	;;
dump)
	dump_config
	;;
add)
	assign_devices
	;;
remove)
	unassign_all_spans
	;;
*)
	usage
	;;
esac