Switch from matrix:// to matrix-federation:// scheme for internal Synapse routing of outbound federation traffic (#15806)

`matrix://` is a registered specced scheme nowadays and doesn't make sense for
our internal to Synapse use case anymore. ([discussion]
(https://github.com/matrix-org/synapse/pull/15773#discussion_r1227598679))

changelog.d/15806.misc

@@ -0,0 +1 @@
+Switch from `matrix://` to `matrix-federation://` scheme for internal Synapse routing of outbound federation traffic.

contrib/lnav/synapse-log-format.json

@@ -29,7 +29,7 @@
         "level": "error"
       },
       {
-        "line": "my-matrix-server-federation-sender-1 | 2023-01-25 20:56:20,995 - synapse.http.matrixfederationclient - 709 - WARNING - federation_transaction_transmission_loop-3 - {PUT-O-3} [example.com] Request failed: PUT matrix://example.com/_matrix/federation/v1/send/1674680155797: HttpResponseException('403: Forbidden')",
+        "line": "my-matrix-server-federation-sender-1 | 2023-01-25 20:56:20,995 - synapse.http.matrixfederationclient - 709 - WARNING - federation_transaction_transmission_loop-3 - {PUT-O-3} [example.com] Request failed: PUT matrix-federation://example.com/_matrix/federation/v1/send/1674680155797: HttpResponseException('403: Forbidden')",
         "level": "warning"
       },
       {

scripts-dev/federation_client.py

@@ -136,11 +136,11 @@ def request(
         authorization_headers.append(header)
         print("Authorization: %s" % header, file=sys.stderr)
 
-    dest = "matrix://%s%s" % (destination, path)
+    dest = "matrix-federation://%s%s" % (destination, path)
     print("Requesting %s" % dest, file=sys.stderr)
 
     s = requests.Session()
-    s.mount("matrix://", MatrixConnectionAdapter())
+    s.mount("matrix-federation://", MatrixConnectionAdapter())
 
     headers: Dict[str, str] = {
         "Authorization": authorization_headers[0],

synapse/http/federation/matrix_federation_agent.py

@@ -51,8 +51,10 @@ logger = logging.getLogger(__name__)
 @implementer(IAgent)
 class MatrixFederationAgent:
     """An Agent-like thing which provides a `request` method which correctly
-    handles resolving matrix server names when using matrix://. Handles standard
+    handles resolving matrix server names when using `matrix-federation://`. Handles
-    https URIs as normal.
+    standard https URIs as normal. The `matrix-federation://` scheme is internal to
+    Synapse and we purposely want to avoid colliding with the `matrix://` URL scheme
+    which is now specced.
 
     Doesn't implement any retries. (Those are done in MatrixFederationHttpClient.)
 
@@ -167,14 +169,14 @@ class MatrixFederationAgent:
         # There must be a valid hostname.
         assert parsed_uri.hostname
 
-        # If this is a matrix:// URI check if the server has delegated matrix
+        # If this is a matrix-federation:// URI check if the server has delegated matrix
         # traffic using well-known delegation.
         #
         # We have to do this here and not in the endpoint as we need to rewrite
         # the host header with the delegated server name.
         delegated_server = None
         if (
-            parsed_uri.scheme == b"matrix"
+            parsed_uri.scheme == b"matrix-federation"
             and not _is_ip_literal(parsed_uri.hostname)
             and not parsed_uri.port
         ):
@@ -250,7 +252,7 @@ class MatrixHostnameEndpointFactory:
 
 @implementer(IStreamClientEndpoint)
 class MatrixHostnameEndpoint:
-    """An endpoint that resolves matrix:// URLs using Matrix server name
+    """An endpoint that resolves matrix-federation:// URLs using Matrix server name
     resolution (i.e. via SRV). Does not check for well-known delegation.
 
     Args:
@@ -379,7 +381,7 @@ class MatrixHostnameEndpoint:
         connect to.
         """
 
-        if self._parsed_uri.scheme != b"matrix":
+        if self._parsed_uri.scheme != b"matrix-federation":
             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

synapse/http/matrixfederationclient.py

@@ -174,7 +174,14 @@ class MatrixFederationRequest:
 
         # The object is frozen so we can pre-compute this.
         uri = urllib.parse.urlunparse(
-            (b"matrix", destination_bytes, path_bytes, None, query_bytes, b"")
+            (
+                b"matrix-federation",
+                destination_bytes,
+                path_bytes,
+                None,
+                query_bytes,
+                b"",
+            )
         )
         object.__setattr__(self, "uri", uri)
 

tests/federation/test_federation_client.py

@@ -124,7 +124,7 @@ class FederationClientTest(FederatingHomeserverTestCase):
         # check the right call got made to the agent
         self._mock_agent.request.assert_called_once_with(
             b"GET",
-            b"matrix://yet.another.server/_matrix/federation/v1/state/%21room_id?event_id=event_id",
+            b"matrix-federation://yet.another.server/_matrix/federation/v1/state/%21room_id?event_id=event_id",
             headers=mock.ANY,
             bodyProducer=None,
         )
@@ -232,7 +232,7 @@ class FederationClientTest(FederatingHomeserverTestCase):
         # check the right call got made to the agent
         self._mock_agent.request.assert_called_once_with(
             b"GET",
-            b"matrix://yet.another.server/_matrix/federation/v1/event/event_id",
+            b"matrix-federation://yet.another.server/_matrix/federation/v1/event/event_id",
             headers=mock.ANY,
             bodyProducer=None,
         )

tests/http/federation/test_matrix_federation_agent.py

@@ -292,7 +292,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.agent = self._make_agent()
 
         self.reactor.lookups["testserv"] = "1.2.3.4"
-        test_d = self._make_get_request(b"matrix://testserv:8448/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv:8448/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -393,7 +393,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
 
         self.reactor.lookups["testserv"] = "1.2.3.4"
         self.reactor.lookups["proxy.com"] = "9.9.9.9"
-        test_d = self._make_get_request(b"matrix://testserv:8448/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv:8448/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -532,7 +532,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         # there will be a getaddrinfo on the IP
         self.reactor.lookups["1.2.3.4"] = "1.2.3.4"
 
-        test_d = self._make_get_request(b"matrix://1.2.3.4/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://1.2.3.4/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -568,7 +568,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         # there will be a getaddrinfo on the IP
         self.reactor.lookups["::1"] = "::1"
 
-        test_d = self._make_get_request(b"matrix://[::1]/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://[::1]/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -604,7 +604,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         # there will be a getaddrinfo on the IP
         self.reactor.lookups["::1"] = "::1"
 
-        test_d = self._make_get_request(b"matrix://[::1]:80/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://[::1]:80/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -639,7 +639,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.mock_resolver.resolve_service.side_effect = generate_resolve_service([])
         self.reactor.lookups["testserv1"] = "1.2.3.4"
 
-        test_d = self._make_get_request(b"matrix://testserv1/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv1/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -693,7 +693,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         # there will be a getaddrinfo on the IP
         self.reactor.lookups["1.2.3.5"] = "1.2.3.5"
 
-        test_d = self._make_get_request(b"matrix://1.2.3.5/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://1.2.3.5/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -725,7 +725,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.mock_resolver.resolve_service.side_effect = generate_resolve_service([])
         self.reactor.lookups["testserv"] = "1.2.3.4"
 
-        test_d = self._make_get_request(b"matrix://testserv/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -780,7 +780,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.reactor.lookups["testserv"] = "1.2.3.4"
         self.reactor.lookups["target-server"] = "1::f"
 
-        test_d = self._make_get_request(b"matrix://testserv/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -844,7 +844,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.reactor.lookups["testserv"] = "1.2.3.4"
         self.reactor.lookups["target-server"] = "1::f"
 
-        test_d = self._make_get_request(b"matrix://testserv/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -933,7 +933,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.mock_resolver.resolve_service.side_effect = generate_resolve_service([])
         self.reactor.lookups["testserv"] = "1.2.3.4"
 
-        test_d = self._make_get_request(b"matrix://testserv/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -1009,7 +1009,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
             ),
         )
 
-        test_d = agent.request(b"GET", b"matrix://testserv/foo/bar")
+        test_d = agent.request(b"GET", b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -1042,7 +1042,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         )
         self.reactor.lookups["srvtarget"] = "1.2.3.4"
 
-        test_d = self._make_get_request(b"matrix://testserv/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -1082,7 +1082,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         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")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -1143,7 +1143,9 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.reactor.lookups["xn--bcher-kva.com"] = "1.2.3.4"
 
         # this is idna for bücher.com
-        test_d = self._make_get_request(b"matrix://xn--bcher-kva.com/foo/bar")
+        test_d = self._make_get_request(
+            b"matrix-federation://xn--bcher-kva.com/foo/bar"
+        )
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -1204,7 +1206,9 @@ class MatrixFederationAgentTests(unittest.TestCase):
         )
         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")
+        test_d = self._make_get_request(
+            b"matrix-federation://xn--bcher-kva.com/foo/bar"
+        )
 
         # Nothing happened yet
         self.assertNoResult(test_d)
@@ -1411,7 +1415,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         )
         self.reactor.lookups["target.com"] = "1.2.3.4"
 
-        test_d = self._make_get_request(b"matrix://testserv/foo/bar")
+        test_d = self._make_get_request(b"matrix-federation://testserv/foo/bar")
 
         # Nothing happened yet
         self.assertNoResult(test_d)