#!/bin/sh
# /etc/rc.d/rc.inet1.smart
#
#	personal hack by MN
#
# rc.wireless code has been partially reused in this script
#
# This file contains the smart selector of network interfaces.
# usage:
#
#	rc.inet1.smart
#
#this script is usable if only one wireless devise is avaible...
#this script doesn't provide any WAP support...
# 
# Copyright (c) 2008 and later, Matteo Nunziati
#  All rights reserved.
# Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
# 1- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
# 2- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
# 3- Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without
#    specific prior written permission.
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
# GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
# DAMAGE.


# =============================================================================
#add your setting here...
ESSIDLIST=("essid1" "essid2"  "essid3")
KEYLIST=("key1" "key2" "key3")

# Find the path where wireless tools are installed
for IWPATH in /usr/{bin,sbin} /usr/local/{bin,sbin} /sbin /bin ; do
	if [ -x $IWPATH/iwconfig ] ; then
		break ;
	fi
done

SCANCMD="$IWPATH/iwlist" #no check is done so BE sure you've it installed and setted in your path
SCANDIRECTIVE="scan"
CHECKCMD="$IWPATH/iwconfig"

#find position of wireless interface
j=0;
while [ $j -lt $MAXNICS ]; do
	[ -x $IWPATH/iwconfig ] || return 1
	LC_ALL=C $IWPATH/iwconfig "${IFNAME[$j]}" 2>&1 | \
	grep -Eiq "no wireless extensions|no such device" || break;
	j=$(($j+1))
done

WLAN_ESSID[$j]=""
IPADDR[$j]=""
AVAIBLENET=$($SCANCMD ${IFNAME[$j]} $SCANDIRECTIVE)
POWER_OLD=-1000;
w=-1
for (( k=0; k<${#ESSIDLIST[@]}; k++ )); do
	[ `echo "$AVAIBLENET" | grep ${ESSIDLIST[k]}` ] && {
		POWER=`echo "$AVAIBLENET" | grep -A8 ${ESSIDLIST[k]} | tail -1 | awk '{printf $3}' | cut -f2 -d = \
		| cut -f1 -d "/" `
		echo "detected wireless essid \"${ESSIDLIST[k]}\" with level: $POWER dB"
		[ $POWER -gt $POWER_OLD ] && { WLAN_ESSID[$j]=${ESSIDLIST[k]}; w=$k;}
		POWER_OLD=$POWER
	};
done

#if we haven't any matching net we disable dhcp and we leave IPADDR empty
#so rc.inet1 will skip this interface;
#else we set the right key and we disable wired devices (we need just one interface on a common laptop).
[ "${WLAN_ESSID[$j]}" = "" ] && { USE_DHCP[$j]=""; echo "switch to wired network";} || {
	WLAN_KEY[$j]="${KEYLIST[w]}";
	for (( k=0; k<$MAXNICS; k++ )); do
		[ ! $k -eq $j ] && { USE_DHCP[$k]=""; IPADDR[$k]=""; }
	done
	echo "selected wireless network: ${WLAN_ESSID[$j]}"
}