Apply an IP range blacklist to push and key revocation requests. (#8821)

Replaces the `federation_ip_range_blacklist` configuration setting with an
`ip_range_blacklist` setting with wider scope. It now applies to:

* Federation
* Identity servers
* Push notifications
* Checking key validitity for third-party invite events

The old `federation_ip_range_blacklist` setting is still honored if present, but
with reduced scope (it only applies to federation and identity servers).

1 files changed, 8 insertions, 18 deletions

diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py

index 4e27f93b7a..c962994727 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -26,11 +26,10 @@ import treq
 from canonicaljson import encode_canonical_json
 from prometheus_client import Counter
 from signedjson.sign import sign_json
-from zope.interface import implementer
 
 from twisted.internet import defer
 from twisted.internet.error import DNSLookupError
-from twisted.internet.interfaces import IReactorPluggableNameResolver, IReactorTime
+from twisted.internet.interfaces import IReactorTime
 from twisted.internet.task import _EPSILON, Cooperator
 from twisted.web.http_headers import Headers
 from twisted.web.iweb import IBodyProducer, IResponse
@@ -45,7 +44,7 @@ from synapse.api.errors import (
 from synapse.http import QuieterFileBodyProducer
 from synapse.http.client import (
     BlacklistingAgentWrapper,
-    IPBlacklistingResolver,
+    BlacklistingReactorWrapper,
     encode_query_args,
     readBodyToFile,
 )
@@ -221,31 +220,22 @@ class MatrixFederationHttpClient:
         self.signing_key = hs.signing_key
         self.server_name = hs.hostname
 
-        real_reactor = hs.get_reactor()
-
         # We need to use a DNS resolver which filters out blacklisted IP
         # addresses, to prevent DNS rebinding.
-        nameResolver = IPBlacklistingResolver(
-            real_reactor, None, hs.config.federation_ip_range_blacklist
+        self.reactor = BlacklistingReactorWrapper(
+            hs.get_reactor(), None, hs.config.federation_ip_range_blacklist
         )
 
-        @implementer(IReactorPluggableNameResolver)
-        class Reactor:
-            def __getattr__(_self, attr):
-                if attr == "nameResolver":
-                    return nameResolver
-                else:
-                    return getattr(real_reactor, attr)
-
-        self.reactor = Reactor()
-
         user_agent = hs.version_string
         if hs.config.user_agent_suffix:
             user_agent = "%s %s" % (user_agent, hs.config.user_agent_suffix)
         user_agent = user_agent.encode("ascii")
 
         self.agent = MatrixFederationAgent(
-            self.reactor, tls_client_options_factory, user_agent
+            self.reactor,
+            tls_client_options_factory,
+            user_agent,
+            hs.config.federation_ip_range_blacklist,
         )
 
         # Use a BlacklistingAgentWrapper to prevent circumventing the IP