#!/bin/bash
# **** License ****
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# 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.
#
# 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 ****

progname=${0##*/}
debug=
match=
attr_address=0:0:0:0:0:0
declare -i ethn=0 last_ethn=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}
: ${vyatta_sbindir:=${vyatta_prefix}/sbin}
: ${vyatta_sysconfdir:=${vyatta_prefix}/etc}
: ${BOOTFILE:=${vyatta_sysconfdir:-/opt/vyatta/etc}/config/config.boot}
: ${DEFAULT_BOOTFILE:=${vyatta_sysconfdir:-/opt/vyatta/etc}/config.boot.default}

if [ ! -f $BOOTFILE ] ; then
    cp $DEFAULT_BOOTFILE $BOOTFILE
    chgrp vyattacfg $BOOTFILE 
    chmod 660 $BOOTFILE
fi

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 ))

finish ()
{
    local cmd=$1 name=$2 address=$3

    echo $name
    touch /tmp/${progname}_${cmd}_${name}_${address} &> /dev/null
    exit $?
}

for name_hwid in ${cfg_net_hwid[@]} ; do
    name=${name_hwid%=*}
    hwid=${name_hwid#*=}
    ethn=${name/eth/}
    [[ $ethn -gt $last_ethn ]] && \
	last_ethn=$ethn
    if [ "$hwid" == "$attr_address" ] ; then
	# we mod the config file interface sub-clock in case it is missing
	finish mod $name $attr_address
    fi
    [ "$name" == "$kname" ] && \
	match=$name_hwid
done

[ -z "$kname" ] && \
    exit 1

# have not found matching hwid in config, see if we can use kernel name
if [ -z "$match" ] ; then
    # the kernel interface name isnot in config
    # so, we might as well use it
    finish add $kname $attr_address
elif [ -z "${match#*=}" ] ; then
    # the config has this interface but the sub-block is missing the hwid
    # so again, we might as well use the kernel name
    finish mod $kname $attr_address
else
    # The device mac address is not in the config but the config
    # has another hwid associated with the device name.  This
    # indicates that the device is either a replacement or new but
    # detected earlier than the device configured with this name.
    # Since this is non-deterministic, we make a new name.
    (( ethn = last_ethn + 1 ))
    finish add eth$ethn $attr_address
fi

# Local Variables:
# mode: shell-script
# sh-indentation: 4
# End: