#!/usr/bin/python3
# Copyright (c) 2014, Ralf Jung <post@ralfj.de>
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer. 
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# 
# The views and conclusions contained in the software and documentation are those
# of the authors and should not be interpreted as representing official policies, 
# either expressed or implied, of the FreeBSD Project.

import urllib.request, socket, sys

# configuration variables
server = 'ns.ralfj.de'
domains = ['domain.dyn.ralfj.de'] # list of domains to update
password = 'yourpassword'
# END of configuration variables

def urlopen(url):
    return urllib.request.urlopen(url).read().decode('utf-8').strip()

myip = urlopen('https://'+server+'/checkip')

def update_domain(domain):
    '''Update the given domain, using the global server, user, password. Returns True on success, False on failure.'''
    global myip
    # check if the domain is already mapped to our current IP
    domainip = socket.gethostbyname(domain)
    if myip == domainip:
        # nothing to do
        return True

    # we need to update the IP
    result = urlopen('https://'+server+'/update?password='+urllib.parse.quote(password)+'&domain='+urllib.parse.quote(domain)+'&ip='+urllib.parse.quote(myip))
    if 'good '+myip == result: 
        # all went all right
        return True
    else:
        # Something went wrong
        print("Unexpected answer from server",server,"while updating",domain,"to",myip)
        print(result)
        return False

exitcode = 0
for domain in domains:
    if not update_domain(domain):
        exitcode = 1
sys.exit(exitcode)