gen_iptable.py

from cStringIO import StringIO

def gen_iptable_rules(rules):
    """
    rules = [
             (port, [allow_ip0, allow_ip1...]),
             ...
            ]
    """
    iptables = StringIO()

    iptables.write("*filter\n\n-A INPUT -i lo -j ACCEPT\n\n")

    for r in rules:
        for ip in r[1]:
            ACTEMP = "-A INPUT -p tcp -m tcp --dport %d -s %s -j ACCEPT\n"
            iptables.write(ACTEMP % (r[0], ip))

        RJTEMP = "-A INPUT -p tcp -m tcp --dport %d -j REJECT\n"
        iptables.write(RJTEMP % (r[0]))
        iptables.write('\n')

    iptables.write("COMMIT\n\n######################################\n")
    iptables.write("# ref: http://wiki.debian.org/iptables\n")
    return iptables


def _test():
    allow_ips = ["192.168.20.1", "192.168.20.2"]
    rules = [(1986, allow_ips), (1987, allow_ips)]      # list of (port, allow_ip_list)

    print gen_iptable_rules(rules).getvalue()



if __name__ == "__main__":
    _test()