#!/bin/bash
# openAircard320U.sh
# written by bob fulton BRAEWORKS Nov 2012
# script to disconnect a Telstra Bigpond Sierra Wireless Aircard 320U USB dongle
# have not needed to use this script as part of the system events
# provided AS IS, no warranties, etc. are provided
# after a few requests added the read back from the modem

VERSION=V1.11
PROG="$(basename $0)"
BASEDIR="/custom/broadband"

. ${BASEDIR}/commonAircard320U.inc

echo "Start $PROG $VERSION on $(date '+%Y/%m/%d %H:%M:%S')"

if [ ! -z "$USER" -a "$USER" != "root" ]; then
        echo "Must be root (not $USER) user to execute $PROG."
        exit 1
fi

# echo "kill dhclient for $NET_ETH"	# test
TST=$(ps ax | grep 'dhclient' | grep $NET_ETH | grep -v 'grep')
if [ ! -z "$TST" ]; then
    echo "Stop dhclient on $NET_ETH"
    PID=$(echo "$TST" | awk '{ print $1 }')
    kill -s HUP "$PID"

	echo "Clean up the dhclient mess"
	sleep 5
	rm -f "/etc/resolv.conf"
	cp -f "${BASEDIR}/resolv.conf-standard" "/etc/resolv.conf"
	"/etc/init.d/named" restart	# restart dns server
fi

# NOTE: the "resolv.conf-standard" contains a clean version of "/etc/resolv.conf".
# the dhclient does not revert the "/etc/resolv.conf" cleanly with a signal lost or lease renew fail
# E.G. of a my clean "/etc/resolv.conf" saved in "resolv.conf-standard"
# snip start
#-- ; resolv.conf-standard - used to replace the stuffed /etc/reslov.conf that dhclient leaves behind
#-- search braeworks.local
#-- nameserver 192.168.0.9
# snip end
# (remove the leading single #-- )

USBTERM_RESPONSE=""	# sometimes the doggle provides erronenous responses (typically trying to use part of a previous command)
function usbTermCmd() {	# $1=outCmd, [$2=-v (verbose)]
	USBTERM_RESPONSE=""
	echo -e "${1}\r" > "$MODEM_PORT"
	while read -t $READ_TOUT R
	do
		if [ "${#R}" -lt 1 ]; then continue; fi	# forget blank lines
		USBTERM_RESPONSE="$R"	# save the last line (usually OK or ERROR)
		if [ ! -z "$2" -a "$2" == "-v" ]; then echo "$R"; fi
	done < "$MODEM_PORT"
	return 0
} # usbTermCmd()

# check its there
TST=$(usb-devices 2> /dev/null | grep "Product=AirCard 320U")
if [ -z "$TST" ]; then
	echo "Sierra Wireless AirCard 320U not found"
else
	# echo "Disconnect"	# test
	usbTermCmd "AT!SCACT=0,$MPPID" > /dev/null
	if [ "$USBTERM_RESPONSE" == "OK" ]; then
		echo "Disconnected"
	fi
fi

echo "Reload network defaults"	# test
/etc/init.d/network restart

echo "Finished $PROG $VERSION on $(date '+%Y/%m/%d %H:%M:%S')"
echo ""

# EOF