#!/bin/sh
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# Copyright (C) 2018 - David Oberhollenzer
#
# 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, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
NAMERULES="@ETCPATH@/netcfg/ifrename"
TMPPATH="/tmp/ifrename"

[ -f "$NAMERULES" ] || exit 0

mkdir -p "$TMPPATH"

for IFPATH in /sys/class/net/*; do
	[ "$IFPATH" == "/sys/class/net/lo" ] && continue

	IF=`basename $IFPATH`
	MAC=`cat $IFPATH/address`

	grep "^[^,]\+,[^,]\+,[a-zA-Z0-9]\+$" $NAMERULES | while read LINE;
	do
		NAMECMP=$(echo $LINE | cut -d',' -f1)
		ADDRCMP=$(echo $LINE | cut -d',' -f2)
		RULE=$(echo $LINE | cut -d',' -f3)

		case $IF in ($NAMECMP) ;; *) continue;; esac
		case $MAC in ($ADDRCMP) ;; *) continue;; esac

		echo "$MAC,$IF" >> "$TMPPATH/$RULE"
		break
	done
done

for FNAME in $TMPPATH/*; do
	[ ! -f "$FNAME" ] && break

	IDX=0
	PREFIX=$(basename $FNAME)

	sort -t',' -k1 -u $FNAME | while read LINE;
	do
		OLDNAME=$(echo $LINE | cut -d',' -f2)
		NEWNAME="$PREFIX$IDX"
		IDX=`expr $IDX + 1`

		ip link set "$OLDNAME" name "$NEWNAME"
	done

	rm "$FNAME"
done

rmdir "$TMPPATH"