wlan-toggle

#!/bin/bash
#
set -e

# TODO:
#
# * setup tinc, if necessary

if [ $(id -u) -ne 0 ]; then
    printf "be root or be sorry\n"
    exit 1
fi

DEV=wlan0
CONFIG_FILE=/etc/wpa_supplicant.conf
DHCP_TOOL=/sbin/dhcpcd
WPA_TOOL=/sbin/wpa_supplicant
MODE=""
IP_REFRESH=0
DHCP_KILL=0

print_usage() {
    printf "\n${0}: script for easy setup for WLAN\n\n"
    printf "\n${0} <-m MODE> <-krdh>"
    printf "parameters:\n"
    printf "  -m <MODE>     available modes are: start, stop, restart, status\n"
    printf "  -k            kill dhcp-tool\n"
    printf "  -r            refresh IP (or get a new one) with ${DHCPTOOL}\n"
    printf "  -d            specify device (default: wlan0)\n"
    printf "  -h            print this help\n\n"
}

kill_dhcp() {
    DHCP_PID=$(pidof $DHCP_TOOL || echo "")
    if [ -n "$DHCP_PID" ]; then
        kill $DHCP_PID
        sleep 1
        DHCP_PID=$(pidof $DHCP_TOOL || echo "")
        if [ -z $DHCP_PID ]; then
            printf "tried to kill $DHCP_TOOL with pid $DHCP_PID: it's still running\n "
        else
            printf "killed $DHCP_TOOL with pid $DHCP_PID\n "
        fi
    else
        printf "no $DhCP_TOOL running. none kiled\n"
    fi
}

refresh_IP() {
    if [ -n "$(pidof $DHCP_TOOL)" ]; then
        printf "$DHCP_TOOL still running, killing it\n"
        kill_dhcp
    fi

    if [ -z "$(pidof $WPA_TOOL)" -a \
         "$DEV" == "wlan0" ]; then
        printf "$WPA_TOOL not running, probably not connected to anything.\n"
        exit 
    fi
    
    $DHCP_TOOL $DEV
    LIP=$(/bin/ip addr show dev $DEV |grep "inet "|cut -d ' ' -f 6)
    LROUTER=$(ip r | grep default|cut -d ' ' -f 3)
    printf "got %s. routing via %s\n" $LIP $LROUTER
}

wlan_start() {
    # todo: check dev status
    WSUP_PID=$(/bin/pidof /sbin/wpa_supplicant || echo "")
    if [ -z "$WSUP_PID" ]; then
        /sbin/ip link set $DEV up
        /sbin/wpa_supplicant -i${DEV} -c${CONFIG_FILE} 2>&1 > /dev/null &
        printf "started wpa_supplicant im detached mode\n"
        sleep 2
        refresh_IP
    else
        printf "wpa_supplicant already running.\n"
    fi
}

wlan_stop() {

    kill_dhcp
    WSUP_PID=$(pidof /sbin/wpa_supplicant || echo "")
    if [ -n "$WSUP_PID" ]; then
        kill $WSUP_PID
        printf "killed wpa_supplicant\n"
    else
        printf "wpa_supplicant not running\n"
    fi
    /sbin/ip link set $DEV down
}

wlan_restart() {
    wlan_stop
    wlan_start
}

wlan_status() {
    LIP=$(/bin/ip addr show dev $DEV |grep "inet "|cut -d ' ' -f 6)
    LROUTER=$(ip r | grep default|cut -d ' ' -f 3)

    # TODO: implement status output
    #printf "\nconnected on:\n"
    printf "interface: %s\n" ${DEV}
    for i in ${LIP}; do
        printf "IP       : %s\n" ${i}
    done
    printf "router   : %s\n" ${LROUTER}
    #    printf "\n"    
}

### int main (){}; ###
while getopts "m:krdh" opt; do
    case $opt in
        m)
            if [ "$OPTARG" == "start" -o \
                 "$OPTARG" == "stop" -o \
                 "$OPTARG" == "restart" -o \
                 "$OPTARG" == "status" ]; then
                MODE=$OPTARG
            fi
            ;;
        k)
            DHCP_KILL=1
            ;;
        r)
            IP_REFRESH=1
            ;;
        d)
            DEV=$OPTARG
            ;;
        h|*)
            print_usage
            exit 0
            ;;
    esac
done

if [ $IP_REFRESH -eq 1 ]; then
    refresh_IP
    exit 0
fi
if [ $DHCP_KILL -eq 1 ]; then
    kill_dhcp
    exit 0
fi

if [ "$MODE" == "start" ]; then
    wlan_start
elif [ "$MODE" == "stop" ]; then
    wlan_stop
elif [ "$MODE" == "restart" ]; then
    wlan_restart
elif [ "$MODE" == "status" ]; then
    wlan_status
fi