diff options
Diffstat (limited to 'he-dyndns')
| -rwxr-xr-x | he-dyndns | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/he-dyndns b/he-dyndns new file mode 100755 index 0000000..bec3b60 --- /dev/null +++ b/he-dyndns @@ -0,0 +1,162 @@ +#!/usr/bin/env python3 + +import argparse +import base64 +import configparser +import dns.resolver +import ipaddress +import logging +import logging.handlers +import os.path +import socket +import sys +import urllib + + +HE_DNS_API_HOST = "dyn.dns.he.net" + +def build_ip(ip_string): + try: + ip = ipaddress.ip_address(ip_string) + except ValueError: + log.error("manually specified address is invalid format: %s" % ip_string) + sys.exit(1) + except: + log.error(str(e)) + sys.exit(1) + + return ip + +def haveIPv6(): + haveIPv6 = True + try: + s = socket.socket(socket.AF_INET6) + s.connect((HE_DNS_API_HOST,80)) + except socket.gaierror as e: + log.debug("Exception {}".format(e.__class__)) + log.error("Testing IPv6 connection: " + str(e)) + sys.exit(1) + except OSError as e: + log.debug("Exception {}".format(e.__class__)) + log.debug(str(e)) + haveIPv6 = False + except TimeoutError as e: + log.error("Testing IPv6 connection: " + str(e)) + sys.exit(1) + except Exception as e: + log.debug("Exception {}".format(e.__class__)) + log.error(str(e)) + haveIPv6 = False + return haveIPv6 + +def getKey(keyfile, record): + if not os.path.exists(keyfile): + raise Exception("missing keyfile {}".format(keyfile)) + + config = configparser.ConfigParser() + config.read(keyfile) + + if not "keys" in config: + raise Exception("keyfile lacks [keys] section") + + if not record in config["keys"]: + raise Exception("keyfile has no entry for {}".format(record)) + + return config["keys"][record] + +def main(): + ap = argparse.ArgumentParser(description="Update Hurricane Electric DNS dynamic record") + ap.add_argument("record", help="DNS record to update") + ap.add_argument("--v4", help="Update IPv4 A record (default)", action="store_true", default=True) + ap.add_argument("--v6", help="Update IPv6 AAAA record", action="store_true", default=False) + ap.add_argument("--addr4", help="Update A record with provided IP rather than detected IP") + ap.add_argument("--addr6", help="Update AAAA record with provided IP rather than detected IP") + ap.add_argument("--keyfile", help="Alternate location for key config file (default /etc/he-dns-secret.conf)") + ap.add_argument("--key", help="HE DDNS key for record (by default read from /etc/he-dns-secret.conf or --keyfile)") + ap.add_argument("--debug", help="Enable debug logging", action="store_true", default=False) + args = ap.parse_args() + + if args.debug: + log.setLevel(logging.DEBUG) + else: + log.setLevel(logging.ERROR) + + if args.keyfile: + log.debug("KEYFILE: {}".format(args.keyfile)) + keyfile = args.keyfile + else: + log.debug("KEYFILE: /etc/he-dyndns.conf") + keyfile = "/etc/he-dyndns.conf" + + if args.addr4: + ip = build_ip(args.addr4) + + if args.addr6: + ip = build_ip(args.addr6) + + if args.v6: + if not haveIPv6 and not args.addr6: + log.error("no IPv6 detected and --v6 specified without --addr6 (try --debug?)") + sys.exit(1) + + try: + + if args.key: + log.debug("--key override; ignore --kefile") + apikey = args.key + else: + apikey = getKey(keyfile, args.record) + + if args.v6: + ans = dns.resolver.resolve(HE_DNS_API_HOST, "AAAA")[0] + log.debug("DNS resolved: {}".format(ans.to_text())) + apihost = "[{}]".format(ans.to_text()) + else: + ans = dns.resolver.resolve(HE_DNS_API_HOST, "A")[0] + log.debug("DNS resolved: {}".format(ans.to_text())) + apihost = ans.to_text() + + # build the API URL to be called + url = "http://{}/nic/update?hostname={}".format(apihost, args.record) + if args.addr4 or args.addr6: + url += "&myip={}".format(ip) + log.debug("API request URL: " + url) + + # make the HTTP request + authstr = base64.b64encode(bytes("%s:%s" % ( args.record, apikey ), "ascii")) + log.debug("auth string: %s" % authstr.decode("utf-8")) + req = urllib.request.Request(url) + req.add_header("Host", HE_DNS_API_HOST) + req.add_header("Authorization", "Basic %s" % authstr.decode("utf-8")) + with urllib.request.urlopen(req) as response: + this_page = response.read() + log.debug("HE response: " + this_page.decode("utf-8")) + res = this_page.decode("utf-8").split()[0] + + if res == "good": + return True + elif res == "badauth": + raise Exception("HE badauth: wrong key or record not configured for dynamic updates") + elif res == "nochg": + return True + else: + raise Exception("HE returned {}: unknown response code".format(res)) + + except dns.resolver.NXDOMAIN as e: + log.debug("Exception class: {}".format(e.__class__)) + log.error(str(e)) + sys.exit(1) + + except Exception as e: + log.debug("Exception class: {}".format(e.__class__)) + log.error(str(e)) + sys.exit(1) + +if __name__ == "__main__": + log = logging.getLogger("he-dyndns") + lh = logging.StreamHandler() + lf = logging.Formatter(fmt='%(name)s: %(levelname)s: %(message)s') + lh.setFormatter(lf) + log.addHandler(lh) + main() + sys.exit(0) |