introduce a configuration file for dyn-ns-client

[dyn-nsupdate.git] / client-scripts / dyn-ns-client

diff --git a/client-scripts/dyn-ns-client b/client-scripts/dyn-ns-client
index 6af3934799f83a529950b10912ed74f3ab84c21f..af263b76aca5111812a19a38ffbcc4f6b9714c23 100755 (executable)
--- a/client-scripts/dyn-ns-client
+++ b/client-scripts/dyn-ns-client
@@ -1,39 +1,156 @@
 #!/usr/bin/python3
 #!/usr/bin/python3

-import urllib.request, socket, sys
+# 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.
+#==============================================================================

 
 

-# configuration variables
-server = 'ns.ralfj.de'
-domains = ['domain.dyn.ralfj.de'] # list of domains to update
-password = 'yourpassword'
-# END of configuration variables
+import urllib.request, socket, sys, argparse, os, configparser, itertools
+
+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):
 
 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)
+    return urllib.request.urlopen(url).read().decode('utf-8').strip()
+
+def getMyIP(family, config, methods = {}, verbose = False):
+    '''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 == 'web':
+        server = config[family].get('server', config['DEFAULT']['server'])
+        ip = urlopen('https://'+server+'/checkip')
+        if verbose:
+            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 = False):
+    '''Returns our current IPv4 address, detected as given by the configuration'''
+    return getMyIP("IPv4", config, verbose=verbose)
+
+def getMyIPv6(config, verbose = False):
+    '''Returns our current IPv6 address, detected as given by the configuration'''
+    return getMyIP("IPv6", config, 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, 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:
+        print("Current status of domain {0} is: IPv4 address '{1}', IPv6 address '{2}'".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:
+            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
+    result = urlopen(url)
+    
+    # did everything go as planned?
+    if result == expected:
+        if verbose:
+            print("Successfully updated domain",domain,"on",server)
+        # all went all right
+        return True
+    else:
+        # Something went wrong
+        print("Unexpected answer from server",server,"while updating",domain)
+        print(result)
+        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="store_true", dest="verbose",
+                        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'], verbose=args.verbose):
+            exitcode = 1
+    sys.exit(exitcode)