Initial commit

1 files changed, 74 insertions, 0 deletions

diff --git a/ddns/backend/dnsupdate.py b/ddns/backend/dnsupdate.py
new file mode 100644
index 0000000..cd1dee2
--- /dev/null
+++ b/ddns/backend/dnsupdate.py
@@ -0,0 +1,74 @@
+import dns.query
+import dns.tsig
+import dns.tsigkeyring
+import dns.update
+import dns.resolver
+import ddns.cfg_parser
+
+zone_cfg = None
+keyring = None
+
+def resolve(domain, rtype='A'):
+	return dns.resolver.query(domain, rtype)
+
+def check_ip(domain, ip, rtype='A'):
+	ans = resolve(domain.encode('ascii'), rtype)
+
+	if not ans:
+		return False
+
+	for rdata in ans:
+		if rdata == ip.strNormal(0):
+			return True
+	return False
+
+def get_zone(name):
+	for zone in zone_cfg:
+		if zone['name'] == name:
+			return zone
+	return None
+
+def gen_keyring(dnskeys):
+	global keyring
+
+	keys = {}
+	for key in dnskeys:
+		keys[key['name']] = key['key']
+
+	keyring = dns.tsigkeyring.from_text(keys)
+
+def get_hash_method(hash_name):
+	if hash_name == 'HMAC-MD5':
+		return dns.tsig.HMAC_MD5
+	if hash_name == 'HMAC-SHA1':
+		return dns.tsig.HMAC_SHA1
+	if hash_name == 'HMAC-SHA224':
+		return dns.tsig.HMAC_SHA224
+	if hash_name == 'HMAC-SHA256':
+		return dns.tsig.HMAC_SHA256
+	if hash_name == 'HMAC-SHA384':
+		return dns.tsig.HMAC_384
+	if hash_name == 'HMAC-SHA512':
+		return dns.tsig.HMAC_512
+	return dns.tsig.default_algorithm
+
+def update_dns(zone, hostname, ip, ttl=300):
+	zone = get_zone(zone)
+	dns_srv = zone['ns']
+
+	update = dns.update.Update(zone['name'], keyring=keyring, \
+			keyname=zone['key']['name'], \
+			keyalgorithm=get_hash_method(zone['key']['algorithm']))
+
+	if ip.version() == 6:
+		rtype = 'AAAA'
+	else:
+		rtype = 'A'
+
+#	if not check_ip(hostname+'.'+zone['name'], ip, rtype):
+	update.replace(hostname.encode('ascii'), ttl, rtype, ip.strNormal(0))
+	res = dns.query.tcp(update, dns_srv)
+
+zone_cfg = ddns.cfg_parser.cfg['zones']
+keyring = gen_keyring(ddns.cfg_parser.cfg['dnskeys'])
+