New, full-fledged python implementation

2 files changed, 223 insertions, 90 deletions

diff --git a/he-dyndns b/he-dyndns
index 0ce3730..26a97b6 100755
--- a/he-dyndns
+++ b/he-dyndns
@@ -1,91 +1,133 @@
-#!/bin/bash
-#
-# Copyright (C)2019 by Jason D. McCormick <jason@mfamily.org>
-# Licensed under the Apache License 2.0. See LICENSE included
-# with the distribution bundle that contained this file.
-#
-
-PATH="/usr/bin:/bin:/usr/sbin:/sbin"
- 
-## KNOWLEDGE IS GOOD ##
-usage() { echo "Usage: $0 [-s SECRET] -d HOSTNAME[,HOSTNAME,...]" 1>&2; exit 1; }
-
-## DO THE UPDATE FUNCTION ONCE FOR HAPPY EDITING ##
-doUpdate() {
-
-	if [ ! -z $2 ]; then
-		myip="&myip=$2"
-	fi
-
-	/usr/bin/curl -s$1 "https://$FQDN:$CODE@$DNSSITE/nic/update?hostname=$FQDN$myip" > $tfile
-	if ! egrep -q '(good|nochg)' $tfile; then
-		echo -n "v$1 change: "
-		cat $tfile
-		echo
-		retval=1
-	fi
-}
-
-## MAIN ##
-while getopts "46a:A:hd:s:" arg; do
-	case "${arg}" in
-		4)
-			DO4=Y
-			;;
-		6)
-			DO6=Y
-			;;
-		a)
-			ADDR4=${OPTARG}
-			;;
-		A)
-			ADDR6=${OPTARG}
-			;;
-		d)
-			FQDNS=${OPTARG}
-			;;
-		s)
-			CODE=${OPTARG}
-			;;
-		*)
-			usage
-			;;
-	esac
-done
-
-if [ -z "${FQDNS}" ]; then
-	usage
-fi
-
-if [ ! -f /etc/he-dns-secret ] && [ -z "${CODE}" ]; then
-	usage
-fi
-
-if [ -z "${CODE}" ]; then
-	. /etc/he-dns-secret
-
-	if [ -z "${CODE}" ]; then
-		echo "/etc/he-dns-secret does not contain a CODE= variable"
-		exit 1
-	fi
-fi
-
-DNSSITE="dyn.dns.he.net";
-retval=0
-tfile=$(/bin/mktemp)
-
-for FQDN in $(echo $FQDNS | tr ',' ' ')
-do
-	if [ ! -z ${DO4} ]; then
-		doUpdate 4 ${ADDR4}
-	fi
-
-	if [ ! -z ${DO6} ]; then
-		doUpdate 6 ${ADDR6}
-	fi
-done
-
-rm $tfile
-
-exit $retval
+#!/usr/bin/env python3
 
+import argparse
+import base64
+import dns.resolver
+import ipaddress
+import logging
+import logging.handlers
+import requests
+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():
+	log.debug("inside 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 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("--key", help="HE DDNS key for record (by default read from /etc/he-dns-secret)")
+	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)
+
+	# Handle manual addressing
+	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.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, "yEuFfO74TskIX2NG0Yod" ), "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)
diff --git a/he-dyndns-bash b/he-dyndns-bash
new file mode 100755
index 0000000..0ce3730
--- /dev/null
+++ b/he-dyndns-bash
@@ -0,0 +1,91 @@
+#!/bin/bash
+#
+# Copyright (C)2019 by Jason D. McCormick <jason@mfamily.org>
+# Licensed under the Apache License 2.0. See LICENSE included
+# with the distribution bundle that contained this file.
+#
+
+PATH="/usr/bin:/bin:/usr/sbin:/sbin"
+ 
+## KNOWLEDGE IS GOOD ##
+usage() { echo "Usage: $0 [-s SECRET] -d HOSTNAME[,HOSTNAME,...]" 1>&2; exit 1; }
+
+## DO THE UPDATE FUNCTION ONCE FOR HAPPY EDITING ##
+doUpdate() {
+
+	if [ ! -z $2 ]; then
+		myip="&myip=$2"
+	fi
+
+	/usr/bin/curl -s$1 "https://$FQDN:$CODE@$DNSSITE/nic/update?hostname=$FQDN$myip" > $tfile
+	if ! egrep -q '(good|nochg)' $tfile; then
+		echo -n "v$1 change: "
+		cat $tfile
+		echo
+		retval=1
+	fi
+}
+
+## MAIN ##
+while getopts "46a:A:hd:s:" arg; do
+	case "${arg}" in
+		4)
+			DO4=Y
+			;;
+		6)
+			DO6=Y
+			;;
+		a)
+			ADDR4=${OPTARG}
+			;;
+		A)
+			ADDR6=${OPTARG}
+			;;
+		d)
+			FQDNS=${OPTARG}
+			;;
+		s)
+			CODE=${OPTARG}
+			;;
+		*)
+			usage
+			;;
+	esac
+done
+
+if [ -z "${FQDNS}" ]; then
+	usage
+fi
+
+if [ ! -f /etc/he-dns-secret ] && [ -z "${CODE}" ]; then
+	usage
+fi
+
+if [ -z "${CODE}" ]; then
+	. /etc/he-dns-secret
+
+	if [ -z "${CODE}" ]; then
+		echo "/etc/he-dns-secret does not contain a CODE= variable"
+		exit 1
+	fi
+fi
+
+DNSSITE="dyn.dns.he.net";
+retval=0
+tfile=$(/bin/mktemp)
+
+for FQDN in $(echo $FQDNS | tr ',' ' ')
+do
+	if [ ! -z ${DO4} ]; then
+		doUpdate 4 ${ADDR4}
+	fi
+
+	if [ ! -z ${DO6} ]; then
+		doUpdate 6 ${ADDR6}
+	fi
+done
+
+rm $tfile
+
+exit $retval
+