limit.py

#!/usr/bin/micropython

import os
import ujson
import time


LIMIT = 100 * 1024 ** 2


def checklimits(macs):
    proc = os.popen("nlbw -c json -g ip,mac")
    data = ujson.loads(proc.read())
    proc = os.popen("iptables -vnL FORWARD")
    iptables = proc.read()
    macindex = data['columns'].index('mac')
    ipindex = data['columns'].index('ip')
    rxindex = data['columns'].index('rx_bytes')
    txindex = data['columns'].index('tx_bytes')
    for row in data['data']:
        mac = row[macindex]
        if mac not in macs:
            continue
        ip = row[ipindex]
        useddata = row[rxindex] + row[txindex]
        print("Processing {} with mac {}".format(ip, mac))

        if useddata > LIMIT:
            print("Limit reached for {}".format(ip))
            if ip not in iptables:
                print("Adding filter")
                os.popen("iptables -I FORWARD -s {} -j DROP".format(ip)).read()
        elif ip in iptables:
            print("Removing filter for {}".format(ip))
            os.popen("iptables -D FORWARD -s {} -j DROP".format(ip)).read()


if __name__ == '__main__':
    macs = ["30:24:32:a9:f8:49", "e0:2c:b2:57:45:64"]
    checklimits(macs)