async def _resolve_server(self) -> List[Server]:
"""Resolves the server name to a list of hosts and ports to attempt to
connect to.
"""
if self._parsed_uri.scheme != b"matrix":
return [
Server(host=self._parsed_uri.host, port=self._parsed_uri.port)
]
# Note: We don't do well-known lookup as that needs to have happened
# before now, due to needing to rewrite the Host header of the HTTP
# request.
# We reparse the URI so that defaultPort is -1 rather than 80
parsed_uri = urllib.parse.urlparse(self._parsed_uri.toBytes())
host = parsed_uri.hostname
port = parsed_uri.port
# If there is an explicit port or the host is an IP address we bypass
# SRV lookups and just use the given host/port.
if port or _is_ip_literal(host):
return [Server(host, port or 8448)]
server_list = await self._srv_resolver.resolve_service(
b"_matrix._tcp." + host)
if server_list:
return server_list
# No SRV records, so we fallback to host and 8448
return [Server(host, 8448)]
def test_srv_fallbacks(self):
"""Test that other SRV results are tried if the first one fails.
"""
self.mock_resolver.resolve_service.side_effect = generate_resolve_service(
[
Server(host=b"target.com", port=8443),
Server(host=b"target.com", port=8444),
])
self.reactor.lookups["target.com"] = "1.2.3.4"
test_d = self._make_get_request(b"matrix://testserv/foo/bar")
# Nothing happened yet
self.assertNoResult(test_d)
self.mock_resolver.resolve_service.assert_called_once_with(
b"_matrix._tcp.testserv")
# We should see an attempt to connect to the first server
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients.pop(0)
self.assertEqual(host, "1.2.3.4")
self.assertEqual(port, 8443)
# Fonx the connection
client_factory.clientConnectionFailed(None, Exception("nope"))
# There's a 300ms delay in HostnameEndpoint
self.reactor.pump((0.4, ))
# Hasn't failed yet
self.assertNoResult(test_d)
# We shouldnow see an attempt to connect to the second server
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients.pop(0)
self.assertEqual(host, "1.2.3.4")
self.assertEqual(port, 8444)
# make a test server, and wire up the client
http_server = self._make_connection(client_factory,
expected_sni=b"testserv")
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
self.assertEqual(request.method, b"GET")
self.assertEqual(request.path, b"/foo/bar")
self.assertEqual(request.requestHeaders.getRawHeaders(b"host"),
[b"testserv"])
# finish the request
request.finish()
self.reactor.pump((0.1, ))
self.successResultOf(test_d)
def test_get_well_known_srv(self):
"""Test the behaviour when the .well-known redirects to a place where there
is a SRV.
"""
self.reactor.lookups["testserv"] = "1.2.3.4"
self.reactor.lookups["srvtarget"] = "5.6.7.8"
test_d = self._make_get_request(b"matrix://testserv/foo/bar")
# Nothing happened yet
self.assertNoResult(test_d)
# there should be an attempt to connect on port 443 for the .well-known
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 443)
self.mock_resolver.resolve_service.side_effect = lambda _: [
Server(host=b"srvtarget", port=8443),
]
self._handle_well_known_connection(
client_factory,
expected_sni=b"testserv",
content=b'{ "m.server": "target-server" }',
)
# there should be a SRV lookup
self.mock_resolver.resolve_service.assert_called_once_with(
b"_matrix._tcp.target-server", )
# now we should get a connection to the target of the SRV record
self.assertEqual(len(clients), 2)
(host, port, client_factory, _timeout, _bindAddress) = clients[1]
self.assertEqual(host, '5.6.7.8')
self.assertEqual(port, 8443)
# make a test server, and wire up the client
http_server = self._make_connection(
client_factory,
expected_sni=b'target-server',
)
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
self.assertEqual(request.method, b'GET')
self.assertEqual(request.path, b'/foo/bar')
self.assertEqual(
request.requestHeaders.getRawHeaders(b'host'),
[b'target-server'],
)
# finish the request
request.finish()
self.reactor.pump((0.1, ))
self.successResultOf(test_d)
def test_get_hostname_srv(self):
"""
Test the behaviour when there is a single SRV record
"""
self.mock_resolver.resolve_service.side_effect = lambda _: [
Server(host=b"srvtarget", port=8443)
]
self.reactor.lookups["srvtarget"] = "1.2.3.4"
test_d = self._make_get_request(b"matrix://testserv/foo/bar")
# Nothing happened yet
self.assertNoResult(test_d)
# the request for a .well-known will have failed with a DNS lookup error.
self.mock_resolver.resolve_service.assert_called_once_with(
b"_matrix._tcp.testserv", )
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 8443)
# make a test server, and wire up the client
http_server = self._make_connection(
client_factory,
expected_sni=b'testserv',
)
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
self.assertEqual(request.method, b'GET')
self.assertEqual(request.path, b'/foo/bar')
self.assertEqual(
request.requestHeaders.getRawHeaders(b'host'),
[b'testserv'],
)
# finish the request
request.finish()
self.reactor.pump((0.1, ))
self.successResultOf(test_d)
def test_idna_srv_target(self):
"""test the behaviour when the target of a SRV record has idna chars"""
self.mock_resolver.resolve_service.side_effect = lambda _: [
Server(host=b"xn--trget-3qa.com", port=8443) # târget.com
]
self.reactor.lookups["xn--trget-3qa.com"] = "1.2.3.4"
test_d = self._make_get_request(b"matrix://xn--bcher-kva.com/foo/bar")
# Nothing happened yet
self.assertNoResult(test_d)
self.mock_resolver.resolve_service.assert_called_once_with(
b"_matrix._tcp.xn--bcher-kva.com", )
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 8443)
# make a test server, and wire up the client
http_server = self._make_connection(
client_factory,
expected_sni=b'xn--bcher-kva.com',
)
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
self.assertEqual(request.method, b'GET')
self.assertEqual(request.path, b'/foo/bar')
self.assertEqual(
request.requestHeaders.getRawHeaders(b'host'),
[b'xn--bcher-kva.com'],
)
# finish the request
request.finish()
self.reactor.pump((0.1, ))
self.successResultOf(test_d)
