-#!/usr/bin/python3
-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)
+#!/usr/bin/env 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.
+#==============================================================================
+
+import urllib.request, socket, sys, argparse, os, configparser, itertools, subprocess, re, ssl
+
+VERBOSE_CHANGE = 1
+VERBOSE_FULL = 2
+
+def sslContext(config):
+ if config['DEFAULT'].get('ssl_check_cert', 'yes').lower() in ('0', 'false', 'no'):
+ context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+ return context
+ else:
+ return None
+
+def readConfig(fname, defSection = 'DEFAULT'):
+ config = configparser.ConfigParser()
+ with open(fname) as file:
+ stream = itertools.chain(("["+defSection+"]\n",), file)
+ config.read_file(stream)
+ return config
+
+def getConfigDir():
+ try:
+ from xdg import BaseDirectory
+ return os.path.join(BaseDirectory.xdg_config_home, "dyn-nsupdate")
+ except ImportError:
+ return os.path.expanduser("~/.config/dyn-nsupdate")
+
+def urlopen(url, config):
+ if sys.version_info >= (3, 4, 3):
+ return urllib.request.urlopen(url, context=sslContext(config)).read().decode('utf-8').strip()
+ else:
+ return urllib.request.urlopen(url).read().decode('utf-8').strip()
+
+def getMyIP(family, config, methods = {}, verbose = 0):
+ '''Returns our current IP address (<family> can be "IPv4" or "IPv6"), detected as given by the configuration.
+ Additional detection methods can be supplied via <methods>.'''
+ method = config[family]['method']
+ if method == 'none':
+ return None
+ elif method == 'remove':
+ return ""
+ elif method == 'web':
+ server = config[family].get('server', config['DEFAULT']['server'])
+ url = 'https://'+server+'/checkip'
+ try:
+ ip = urlopen(url, config)
+ except urllib.error.URLError:
+ raise Exception("Error fetching {}, make sure the URL is correct and the internet connection actually works.".format(url))
+ if verbose >= VERBOSE_FULL:
+ print("Server",server,"says my",family,"is",ip)
+ return ip
+ elif method in methods:
+ return methods[method]()
+ else:
+ raise Exception("Unsupported "+family+" detection method: "+method)
+
+def getMyIPv4(config, verbose = 0):
+ '''Returns our current IPv4 address, detected as given by the configuration'''
+ return getMyIP("IPv4", config, verbose=verbose)
+
+def getMyIPv6(config, verbose = 0):
+ '''Returns our current IPv6 address, detected as given by the configuration'''
+ def local():
+ device = config["IPv6"].get("device")
+ out = subprocess.check_output(["ip", "addr", "show"] + ([] if device is None else ["dev", device]))
+ for line in out.decode('utf-8').split('\n'):
+ m = re.search('inet6 ([a-fA-F0-9:]+)/64 ([a-zA-Z0-9 ]*)', line)
+ if m is not None:
+ ip = m.group(1)
+ flags = m.group(2).split()
+ if not 'temporary' in flags and not 'deprecated' in flags and not "link" in flags:
+ if verbose >= VERBOSE_FULL:
+ print("Local IPv6 detected to be",ip)
+ return ip
+ raise Exception("Unable to detect correct local IPv6 address")
+ return getMyIP("IPv6", config, methods={'local': local}, verbose=verbose)
+
+def getCurIP(domain, family):
+ '''Return the current IP of the given <domain>. <family> can be socket.AF_INET or socket.AF_INET6.'''
+ try:
+ addr = socket.getaddrinfo(domain, None, family=family)
+ return addr[0][4][0]
+ except socket.gaierror: # domain not found
+ return ""
+
+def getCurIPv4(domain):
+ '''Returns the current IPv4 address of the given domain'''
+ return getCurIP(domain, socket.AF_INET)
+
+def getCurIPv6(domain):
+ '''Returns the current IPv6 address of the given domain'''
+ return getCurIP(domain, socket.AF_INET6)
+
+def updateDomain(server, domain, ipv4, ipv6, password, config, verbose):
+ '''Update the given domain, using the server, password. ipv4 or ipv6 can be None to not update that record, or strings with the respective addresses.
+ Updates ae only performed if necessary.
+ Returns True on success, False on failure.'''
+ assert ipv4 is not None or ipv6 is not None
+
+ # check what the domain is currently mapped to
+ curIPv4 = getCurIPv4(domain)
+ curIPv6 = getCurIPv6(domain)
+ if verbose >= VERBOSE_FULL:
+ print("Current status of domain {} is: IPv4 address '{}', IPv6 address '{}'".format(domain, curIPv4, curIPv6))
+
+ # check if there's something to do
+ needUpdate = (ipv4 is not None and curIPv4 != ipv4) or (ipv6 is not None and curIPv6 != ipv6)
+ if not needUpdate:
+ if verbose >= VERBOSE_FULL:
+ print("Everything already up-to-date, nothing to do")
+ return True
+
+ # we need to update the IP
+ url = 'https://'+server+'/update?password='+urllib.parse.quote(password)+'&domain='+urllib.parse.quote(domain)
+ expected = "good"
+ if ipv4 is not None:
+ url += '&ip='+urllib.parse.quote(ipv4)
+ expected += " "+ipv4
+ if ipv6 is not None:
+ url += '&ipv6='+urllib.parse.quote(ipv6)
+ expected += " "+ipv6
+ if verbose >= VERBOSE_FULL:
+ print("Request:",url)
+ result = urlopen(url, config)
+
+ # did everything go as planned?
+ if result == expected:
+ if verbose >= VERBOSE_CHANGE:
+ msg = "Successfully updated domain {} on {}:".format(domain, server)
+ if ipv4 is not None:
+ if curIPv4 == ipv4:
+ msg += " IPv4={} (unchanged)".format(curIPv4)
+ else:
+ msg += " IPv4={} -> {}".format(curIPv4, ipv4)
+ if ipv4 is not None and ipv6 is not None:
+ msg += ","
+ if ipv6 is not None:
+ if curIPv6 == ipv6:
+ msg += " IPv6={} (unchanged)".format(curIPv6)
+ else:
+ msg += " IPv6={} -> {}".format(curIPv6, ipv6)
+ print(msg)
+ # all went all right
+ return True
+ else:
+ # Something went wrong
+ print("Unexpected answer from server",server,"while updating",domain)
+ print("Got '{}', expected '{}'".format(result, expected))
+ return False
+
+if __name__ == "__main__":
+ # allow overwriting some values on the command-line
+ parser = argparse.ArgumentParser(description='Update a domain managed by a dyn-nsupdate server')
+ parser.add_argument("-c", "--config",
+ dest="config", default=os.path.join(getConfigDir(), "dyn-ns-client.conf"),
+ help="The configuration file")
+ parser.add_argument("-v", "--verbose",
+ action="count", dest="verbose", default=0,
+ help="Be more verbose")
+ args = parser.parse_args()
+
+ # read config
+ if not os.path.isfile(args.config):
+ raise Exception("The config file does not exist: "+args.config)
+ config = readConfig(args.config)
+
+ # get our own addresses
+ myIPv4 = getMyIPv4(config, args.verbose)
+ myIPv6 = getMyIPv6(config, args.verbose)
+
+ # update all the domains
+ exitcode = 0
+ domains = map(str.strip, config['DEFAULT']['domains'].split(','))
+ if not domains:
+ raise Exception("No domain given to update!")
+ for domain in domains:
+ if not updateDomain(config['DEFAULT']['server'], domain, myIPv4, myIPv6, config['DEFAULT']['password'], config, verbose=args.verbose):
+ exitcode = 1
+ sys.exit(exitcode)