Factor out an `is_mine_server_name` method (#15542)

Add an `is_mine_server_name` method, similar to `is_mine_id`.

Ideally we would use this consistently, instead of sometimes comparing
against `hs.hostname` and other times reaching into
`hs.config.server.server_name`.

Also fix a bug in the tests where `hs.hostname` would sometimes differ
from `hs.config.server.server_name`.

Signed-off-by: Sean Quah <seanq@matrix.org>

7 files changed, 19 insertions, 13 deletions

diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index 3df975958d..b77022b406 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -49,7 +49,7 @@ class FederationBase:
     def __init__(self, hs: "HomeServer"):
         self.hs = hs
 
-        self.server_name = hs.hostname
+        self._is_mine_server_name = hs.is_mine_server_name
         self.keyring = hs.get_keyring()
         self._spam_checker_module_callbacks = hs.get_module_api_callbacks().spam_checker
         self.store = hs.get_datastores().main
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index 0b2d1a78f7..076b9287c6 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -854,7 +854,7 @@ class FederationClient(FederationBase):
 
         for destination in destinations:
             # We don't want to ask our own server for information we don't have
-            if destination == self.server_name:
+            if self._is_mine_server_name(destination):
                 continue
 
             try:
@@ -1536,7 +1536,7 @@ class FederationClient(FederationBase):
         self, destinations: Iterable[str], room_id: str, event_dict: JsonDict
     ) -> None:
         for destination in destinations:
-            if destination == self.server_name:
+            if self._is_mine_server_name(destination):
                 continue
 
             try:
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index ca43c7bfc0..c590d8f96f 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -129,6 +129,7 @@ class FederationServer(FederationBase):
     def __init__(self, hs: "HomeServer"):
         super().__init__(hs)
 
+        self.server_name = hs.hostname
         self.handler = hs.get_federation_handler()
         self._spam_checker_module_callbacks = hs.get_module_api_callbacks().spam_checker
         self._federation_event_handler = hs.get_federation_event_handler()
@@ -942,7 +943,7 @@ class FederationServer(FederationBase):
             authorising_server = get_domain_from_id(
                 event.content[EventContentFields.AUTHORISING_USER]
             )
-            if authorising_server != self.server_name:
+            if not self._is_mine_server_name(authorising_server):
                 raise SynapseError(
                     400,
                     f"Cannot authorise request from resident server: {authorising_server}",
diff --git a/synapse/federation/send_queue.py b/synapse/federation/send_queue.py
index 0b7c81677e..fb448f2155 100644
--- a/synapse/federation/send_queue.py
+++ b/synapse/federation/send_queue.py
@@ -68,6 +68,7 @@ class FederationRemoteSendQueue(AbstractFederationSender):
         self.clock = hs.get_clock()
         self.notifier = hs.get_notifier()
         self.is_mine_id = hs.is_mine_id
+        self.is_mine_server_name = hs.is_mine_server_name
 
         # We may have multiple federation sender instances, so we need to track
         # their positions separately.
@@ -198,7 +199,7 @@ class FederationRemoteSendQueue(AbstractFederationSender):
         key: Optional[Hashable] = None,
     ) -> None:
         """As per FederationSender"""
-        if destination == self.server_name:
+        if self.is_mine_server_name(destination):
             logger.info("Not sending EDU to ourselves")
             return
 
diff --git a/synapse/federation/sender/__init__.py b/synapse/federation/sender/__init__.py
index edc4b1768c..f3bdc5a4d2 100644
--- a/synapse/federation/sender/__init__.py
+++ b/synapse/federation/sender/__init__.py
@@ -362,6 +362,7 @@ class FederationSender(AbstractFederationSender):
 
         self.clock = hs.get_clock()
         self.is_mine_id = hs.is_mine_id
+        self.is_mine_server_name = hs.is_mine_server_name
 
         self._presence_router: Optional["PresenceRouter"] = None
         self._transaction_manager = TransactionManager(hs)
@@ -766,7 +767,7 @@ class FederationSender(AbstractFederationSender):
         domains = [
             d
             for d in domains_set
-            if d != self.server_name
+            if not self.is_mine_server_name(d)
             and self._federation_shard_config.should_handle(self._instance_name, d)
         ]
         if not domains:
@@ -832,7 +833,7 @@ class FederationSender(AbstractFederationSender):
             assert self.is_mine_id(state.user_id)
 
         for destination in destinations:
-            if destination == self.server_name:
+            if self.is_mine_server_name(destination):
                 continue
             if not self._federation_shard_config.should_handle(
                 self._instance_name, destination
@@ -860,7 +861,7 @@ class FederationSender(AbstractFederationSender):
             content: content of EDU
             key: clobbering key for this edu
         """
-        if destination == self.server_name:
+        if self.is_mine_server_name(destination):
             logger.info("Not sending EDU to ourselves")
             return
 
@@ -897,7 +898,7 @@ class FederationSender(AbstractFederationSender):
             queue.send_edu(edu)
 
     def send_device_messages(self, destination: str, immediate: bool = True) -> None:
-        if destination == self.server_name:
+        if self.is_mine_server_name(destination):
             logger.warning("Not sending device update to ourselves")
             return
 
@@ -919,7 +920,7 @@ class FederationSender(AbstractFederationSender):
         might have come back.
         """
 
-        if destination == self.server_name:
+        if self.is_mine_server_name(destination):
             logger.warning("Not waking up ourselves")
             return
 
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index bc70b94f68..d2fa9976da 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -58,9 +58,9 @@ class TransportLayerClient:
     """Sends federation HTTP requests to other servers"""
 
     def __init__(self, hs: "HomeServer"):
-        self.server_name = hs.hostname
         self.client = hs.get_federation_http_client()
         self._faster_joins_enabled = hs.config.experimental.faster_joins_enabled
+        self._is_mine_server_name = hs.is_mine_server_name
 
     async def get_room_state_ids(
         self, destination: str, room_id: str, event_id: str
@@ -235,7 +235,7 @@ class TransportLayerClient:
             transaction.transaction_id,
         )
 
-        if transaction.destination == self.server_name:
+        if self._is_mine_server_name(transaction.destination):
             raise RuntimeError("Transport layer cannot send to itself!")
 
         # FIXME: This is only used by the tests. The actual json sent is
diff --git a/synapse/federation/transport/server/_base.py b/synapse/federation/transport/server/_base.py
index cdaf0d5de7..b6e9c58760 100644
--- a/synapse/federation/transport/server/_base.py
+++ b/synapse/federation/transport/server/_base.py
@@ -57,6 +57,7 @@ class Authenticator:
         self._clock = hs.get_clock()
         self.keyring = hs.get_keyring()
         self.server_name = hs.hostname
+        self._is_mine_server_name = hs.is_mine_server_name
         self.store = hs.get_datastores().main
         self.federation_domain_whitelist = (
             hs.config.federation.federation_domain_whitelist
@@ -100,7 +101,9 @@ class Authenticator:
                 json_request["signatures"].setdefault(origin, {})[key] = sig
 
                 # if the origin_server sent a destination along it needs to match our own server_name
-                if destination is not None and destination != self.server_name:
+                if destination is not None and not self._is_mine_server_name(
+                    destination
+                ):
                     raise AuthenticationError(
                         HTTPStatus.UNAUTHORIZED,
                         "Destination mismatch in auth header",