#!/bin/sh
# Author: Noah Friedman <friedman@splode.com>
# Created: 2011-10-02
# Public domain

# $Id: eth0-fix,v 1.5 2015/02/25 02:06:19 friedman Exp $

### BEGIN INIT INFO
# Provides:          eth0-fix
# Required-Start:
# Required-Stop:
# X-Start-Before:    $network $netdaemons
# Default-Start:     2 3 4 5
# Default-Stop:
# Short-Description: detect changed MAC for eth0
# Description:       detects changed MAC for eth0 and reconfigures
### END INIT INFO

# chkconfig: 2345 01 99
# description:	detects changed MAC for eth0 and reconfigures

# To add/remove using chkconfig:
#	chkconfig --add eth0-fix
#	chkconfig --del eth0-fix
# To add/remove using insserv:
# 	insserv --default eth0-fix
#	insserv --remove  eth0-fix
# Using update-rc.d:
# 	update-rc.d    eth0-fix defaults
#	update-rc.d -f eth0-fix remove
# To launch from upstart(8), create /etc/init/eth0-fix.conf with the
# following lines:
#	description "detect changed MAC for eth0"
#	start       on net-device-added INTERFACE=eth1
#	exec        /etc/init.d/eth0-fix

start()
{
    if [ -e /sys/class/net/eth1 ] && ! [ -e /sys/class/net/eth0 ]; then
        rules=/etc/udev/rules.d/70-persistent-net.rules
        omac=`sed -ne '/eth0/s/.*{address}=="\([^"]*\)".*/\1/p' $rules`
        read nmac < /sys/class/net/eth1/address

        logger -p daemon.info -t ${0##*/} -i -s \
               Primary ethernet MAC has changed from $omac to $nmac\; \
               renaming eth1 to eth0.

        sed -i \
            -e '/eth0/s/\({address}=="\)[^"]*/\1'"$nmac/" \
            -e '/eth1/d' \
            -e '/# PCI device/d' \
            $rules

        # CentOS 6.x udev generates new rules here before root filesystem
        # is mounted read/write, then the udev-post init script (which runs
        # after this one) appends them to the existing rules.  Delete this
        # one now so that doesn't happen.
        rm -f /dev/.udev/tmp-rules--${rules##*/}

        # Fedora/RHEL/CentOS
        cfg=/etc/sysconfig/network-scripts/ifcfg-eth0
        if [ -f $cfg ] && grep "^HWADDR=" $cfg > /dev/null
        then
            sed -i -e "/^HWADDR=/d" $cfg
        fi

        ip link set eth1 name eth0
        udevadm control --reload-rules
    fi
}

case $1 in
    start | '' ) start ;;
esac

# eof