Initial version

2 files changed, 100 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b25c15b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*~
diff --git a/mdns-resolver b/mdns-resolver
new file mode 100755
index 0000000..b58d55b
--- /dev/null
+++ b/mdns-resolver
@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+
+import errno
+import signal
+import socket
+import subprocess
+import sys
+import threading
+import traceback
+
+import dns.flags
+import dns.message
+import dns.name
+import dns.opcode
+import dns.query
+import dns.rcode
+import dns.rdataclass
+import dns.rdatatype
+import dns.rdtypes.IN.A
+import dns.rdtypes.IN.AAAA
+import dns.rrset
+
+
+### Config ###
+domain         = 'mesh.ffhl'
+port           = 3535
+ttl            = 600
+### Config end ###
+
+
+class ResolverThread(threading.Thread):
+	def __init__(self, data, addr):
+		threading.Thread.__init__(self)
+
+		self.daemon = True
+
+		self._data = data
+		self._addr = addr
+
+	def run(self):
+		request = dns.message.from_wire(self._data, question_only=True)
+		if request.opcode() != dns.opcode.QUERY:
+			return
+
+		reply = dns.message.Message(request.id)
+		reply.flags = dns.flags.QR
+		reply.set_opcode(dns.opcode.QUERY)
+		reply.set_rcode(dns.rcode.NOERROR)
+
+		for question in request.question:
+			if question.rdclass != dns.rdataclass.IN:
+				continue
+
+			domainname = dns.name.from_text(domain)
+			if len(question.name) != len(domainname)+1:
+				continue
+			if not question.name.is_subdomain(domainname):
+				continue
+		
+
+			answer = dns.rrset.RRset(question.name, question.rdclass, question.rdtype)
+			answer.ttl = ttl
+
+			if question.rdtype == dns.rdatatype.A:
+				output = subprocess.check_output(['avahi-resolve', '-n', '-4', question.name[0]+b'.local']).split(b'\t')
+				if output[0] == question.name[0]+b'.local':
+					answer.add(dns.rdtypes.IN.A.A(question.rdclass, question.rdtype, str(output[1], encoding='ASCII').strip()))
+			elif question.rdtype == dns.rdatatype.AAAA:
+				output = subprocess.check_output(['avahi-resolve', '-n', '-6', question.name[0]+b'.local']).split(b'\t')
+				if output[0] == question.name[0]+b'.local':
+					answer.add(dns.rdtypes.IN.AAAA.AAAA(question.rdclass, question.rdtype, str(output[1], encoding='ASCII').strip()))
+			else:
+				continue
+
+			reply.answer.append(answer)
+
+		sock.sendto(reply.to_wire(), self._addr)
+
+run = True
+
+def exitHandler(signum, frame):
+    global run
+    run = False
+
+signal.signal(signal.SIGINT, exitHandler)
+signal.signal(signal.SIGTERM, exitHandler)
+signal.signal(signal.SIGQUIT, exitHandler)
+
+
+sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
+sock.bind(('::1', port))
+
+while run:
+	try:
+		data, addr = sock.recvfrom(1024)
+		ResolverThread(data, addr).start()
+	except socket.error:
+		if sys.exc_info()[1].errno != errno.EINTR:
+			traceback.print_exc(file=sys.stderr)