#!/bin/bash
# **** License ****
# Version: VPL 1.0
#
# The contents of this file are subject to the Vyatta Public License
# Version 1.0 ("License"); you may not use this file except in
# compliance with the License. You may obtain a copy of the License at
# http://www.vyatta.com/vpl
#
# Software distributed under the License is distributed on an "AS IS"
# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
# the License for the specific language governing rights and limitations
# under the License.
#
# This code was originally developed by Vyatta, Inc.
# Portions created by Vyatta are Copyright (C) 2007 Vyatta, Inc.
# All Rights Reserved.
#
# Author:	Tom Grennan <tgrennan@vyatta.com>
# Description:	search Vyatta config for interface name given address
#
# **** End License ****

debug=
match=
attr_address=0:0:0:0:0:0

test -r /etc/default/vyatta && source /etc/default/vyatta

# process command line variable overrides

for arg ; do
    case "$arg" in
    --debug )
	debug=echo
	;;
    --*=* )
	arg=${arg#--}
	eval ${arg%=*}=\"${arg#*=}\"
	;;
    *=* )
	eval ${arg%=*}=\"${arg#*=}\"
	;;
    *:*:*:*:*:* )
	attr_address=$arg
	;;
    * )
	kname=$arg
	;;
    esac
done

: ${vyatta_prefix:=/opt/vyatta}
: ${vyatta_sysconfdir:=${vyatta_prefix}/etc}
: ${BOOTFILE:=${vyatta_sysconfdir:-/opt/vyatta/etc}/config/config.boot}

shopt -s extglob nullglob

# load cfg_eth_hwid array from config file as follows
# interface {
# ...
#     ethernet eth# {
#     ...
#	 hw-id: XX:XX:XX:XX:XX:XX
#     ...
#     }
# }
#
# cfg_eth_hwid=( "eth#=xx:xx:xx:xx:xx:xx" ... )

declare -a cfg_net_hwid=( $( sed -ne '
    /^interfaces {/,/^}/ {
	/^ *ethernet eth[0-9]* {/,/^    $/ {
	    /^ *ethernet/ {
		s/.* eth\([0-9]\+\) {$/ eth\1=/
# hold interface name
		h
	    }
	    /^.*hw-id:/ {
# translate field name
		s/.*hw-id: *//
# tolower hex mac address
		y/ABCDEF/abcdef/
# exchange hold and pattern space
		x
# concatenate hold and pattern
		G
		s/\n//p
	    }
	}
    }' $BOOTFILE ))

for name_hwid in ${cfg_net_hwid[@]} ; do
    name=${name_hwid%=*}
    hwid=${name_hwid#*=}
    if [ "$hwid" == "$attr_address" ] ; then
	echo $name
	exit 0
    fi
    [ "$name" == "$kname" ] && match=$name_hwid
done

# have not found matching hwid in config, see if we can use kernel name
if [ -n "$kname" ] ; then
    # if interface missing entirely from config
    # or it does not yet have a recorded hwid
    # it is safe to use kernel name
    if [[ -z "$match" || -z "${match#*=}" ]] ; then
	echo $kname
	exit 0
    fi
    # FIXME! need to figure out what to do here...

    # The device mac address isn't yet in the config but the config
    # has another hwid associated with the kernel name.  This
    # indicates that the device may have been replaced or a new device
    # installed. Udev may not have scanned all devices yet so we
    # donot know which case.
fi

exit 1

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# mode: shell-script
# sh-indentation: 4
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