#!/bin/sh 
# Made for Acer Aspire 9110 Series
# Load the IPWRAW Wifi module for using the Wifi device to do packet injection
# Author: Advhertz aka Carlo Avversari - advhertz@gmail.com

DEVICE=eth2
module=ipwraw
debug="debug=0x104021"

prog=$0
[ "${prog/*load/load}" = "load" ] || {
    echo "This script must not be sourced."
    return 1
}  || return 1

function die()
{
	ret=$1
	shift
	echo $@ >&2
	exit $ret
}

function is_loaded()
{
    (lsmod | egrep -q -e "^$module[[:space:]]+") && return 0
    return 1
}

function unload()
{
    is_loaded || return 0
    echo -n "Unloading '$module'.."
    modprobe -r $module
    echo ".done."
    is_loaded || return 0
    die 1 "Module unload failed."
}

function load()
{
    echo -n "Loading '$module'.."
    modprobe $module $debug
    is_loaded && echo ".done." && return 0
    
    echo ".failed."

    die 2 "Module load failed."
}

function check_root()
{
    [ $(whoami) != "root" ] &&
    die 1 "You must be root to run this script."
    return 0
}

function wait_for_file()
{
    echo -n "Waiting for $2 to appear."
    elapsed=0
    i=$1
    i=$((i*2))
    while [[ $elapsed<$i ]]; do
	[ -e $2 ] && echo ".done." && return 0
	echo -n "."
	sleep 0.5
	elapsed=$((elapsed+1))
    done
    echo "time out."
    return 1
}

function set_channel()
{
	channel=$1
	band=$2
	printf "Setting channel to %d..." $channel
	echo $channel > /sys/class/net/${DEVICE}/device/channel
	tmp=$(cat /sys/class/net/${DEVICE}/device/channel) ||
		die 1 "failed."
	(( $tmp == $channel )) ||
		die 2 "did not work."
	echo "done."
	
	[ $band ] && {
	    printf "Setting band to %d..." $band
	    echo $band > /sys/class/net/${DEVICE}/device/band
	    tmp=$(cat /sys/class/net/${DEVICE}/device/band) || die 1 "failed."
	    (( $tmp == $band )) || die 2 "did not work."
	    echo "done."
	} || true
}

check_root
unload
load

(( $# > 0 )) && {
	channel=$1
	shift
} || channel=1

(( $# > 0 )) && {
	band=$2
	shift
}

wait_for_file 10 /sys/class/net/${DEVICE}/device/rtap_iface ||
die 3 "Could not find ${DEVICE} interface."

(echo 1 > /sys/class/net/${DEVICE}/device/rtap_iface) ||
die 4 "Could not write to rtap_iface to create rtap interface."

iface=$(cat /sys/class/net/${DEVICE}/device/rtap_iface) ||
die 5 "Could not read from rtap_iface to determine rtap interface."

[ "$iface" != "-1" ] || die 6 "Could not create rtap interface."

ifconfig $iface up || die 7 "Could not bring up rtap interface."

set_channel $channel $band|| 
die 5 "Could not tune to channel $channel."

cat << EOM

Interface up as $iface and ready for application connection.  

EOM