Remailer support

Adds "remailer_canonical" request that allows canonical_map address rewriting with Postfix for uffd's remailer feature.

test_server.py

@@ -60,14 +60,18 @@ class MockConnection:
 		pass
 
 class UffdAPIMock:
-	def __init__(self, aliases=None):
+	def __init__(self, aliases=None, remailer_map=None):
 		self.aliases = aliases or {}
+		self.remailer_map = remailer_map or {}
 
 	def get_aliases(self, mail_address):
 		return self.aliases.get(mail_address, [])
 
+	def resolve_remailer(self, orig_address):
+		return self.remailer_map.get(orig_address, None)
+
 class TestSocketmapsRequestHandler(unittest.TestCase):
-	def test_handle(self):
+	def test_handle_virtual(self):
 		api = UffdAPIMock(aliases={
 			'test@example.com': ['test-dest@example.com'],
 			'space test@example.com': ['space test dest@example.com'],
@@ -136,3 +140,28 @@ class TestSocketmapsRequestHandler(unittest.TestCase):
 		conn = MockConnection(request, 4096)
 		RequestHandler(conn, '', None).handle()
 		self.assertIn(b'PERM ', conn.sent)
+
+	def test_handle_remailer(self):
+		api = UffdAPIMock(remailer_map={
+			'v1-23-testuser@remailer.example.com': 'testuser@example.com',
+			'v1-23-testadmin@remailer.example.com': 'testadmin@example.com',
+		})
+		RequestHandler = make_requesthandler(api)
+
+		request = b'54:remailer_canonical v1-23-testuser@remailer.example.com,'
+		response = b'23:OK testuser@example.com,'
+		conn = MockConnection(request, 4096)
+		RequestHandler(conn, '', None).handle()
+		self.assertEqual(conn.sent, response)
+
+		request = b'56:remailer_canonical v1-42-not-a-user@remailer.example.com,'
+		response = b'9:NOTFOUND ,'
+		conn = MockConnection(request, 4096)
+		RequestHandler(conn, '', None).handle()
+		self.assertEqual(conn.sent, response)
+
+		request = b'35:remailer_canonical test@example.com,'
+		response = b'9:NOTFOUND ,'
+		conn = MockConnection(request, 4096)
+		RequestHandler(conn, '', None).handle()
+		self.assertEqual(conn.sent, response)