Add a cache around server ACL checking

rust/src/acl/mod.rs

@@ -0,0 +1,100 @@
+// Copyright 2023 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! An implementation of Matrix server ACL rules.
+
+use crate::push::utils::{glob_to_regex, GlobMatchType};
+use anyhow::Error;
+use pyo3::prelude::*;
+use regex::Regex;
+use std::net::Ipv4Addr;
+use std::str::FromStr;
+
+/// Called when registering modules with python.
+pub fn register_module(py: Python<'_>, m: &PyModule) -> PyResult<()> {
+    let child_module = PyModule::new(py, "acl")?;
+    child_module.add_class::<ServerAclEvaluator>()?;
+
+    m.add_submodule(child_module)?;
+
+    // We need to manually add the module to sys.modules to make `from
+    // synapse.synapse_rust import acl` work.
+    py.import("sys")?
+        .getattr("modules")?
+        .set_item("synapse.synapse_rust.acl", child_module)?;
+
+    Ok(())
+}
+
+#[derive(Debug, Clone)]
+#[pyclass(frozen)]
+pub struct ServerAclEvaluator {
+    allow_ip_literals: bool,
+    allow: Vec<Regex>,
+    deny: Vec<Regex>,
+}
+
+#[pymethods]
+impl ServerAclEvaluator {
+    #[new]
+    pub fn py_new(
+        allow_ip_literals: bool,
+        allow: Vec<String>,
+        deny: Vec<String>,
+    ) -> Result<Self, Error> {
+        let allow = allow
+            .iter()
+            .map(|s| glob_to_regex(s, GlobMatchType::Whole).unwrap())
+            .collect();
+        let deny = deny
+            .iter()
+            .map(|s| glob_to_regex(s, GlobMatchType::Whole).unwrap())
+            .collect();
+
+        Ok(ServerAclEvaluator {
+            allow_ip_literals,
+            allow,
+            deny,
+        })
+    }
+
+    pub fn server_matches_acl_event(&self, server_name: &str) -> bool {
+        // first of all, check if literal IPs are blocked, and if so, whether the
+        // server name is a literal IP
+        if !self.allow_ip_literals {
+            // check for ipv6 literals. These start with '['.
+            if server_name.starts_with("[") {
+                return false;
+            }
+
+            // check for ipv4 literals. We can just lift the routine from std::net.
+            if let Ok(_) = Ipv4Addr::from_str(server_name) {
+                return false;
+            }
+        }
+
+        // next,  check the deny list
+        if self.deny.iter().any(|e| e.is_match(server_name)) {
+            return false;
+        }
+
+        // then the allow list.
+        if self.allow.iter().any(|e| e.is_match(server_name)) {
+            return true;
+        }
+
+        // everything else should be rejected.
+        false
+    }
+}

rust/src/lib.rs

@@ -2,6 +2,7 @@ use lazy_static::lazy_static;
 use pyo3::prelude::*;
 use pyo3_log::ResetHandle;
 
+pub mod acl;
 pub mod push;
 
 lazy_static! {
@@ -38,6 +39,7 @@ fn synapse_rust(py: Python<'_>, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(get_rust_file_digest, m)?)?;
     m.add_function(wrap_pyfunction!(reset_logging_config, m)?)?;
 
+    acl::register_module(py, m)?;
     push::register_module(py, m)?;
 
     Ok(())

stubs/synapse/synapse_rust/acl.pyi

@@ -0,0 +1,21 @@
+# Copyright 2023 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import List
+
+class ServerAclEvaluator:
+    def __init__(
+        self, allow_ip_literals: bool, allow: List[str], deny: List[str]
+    ) -> None: ...
+    def server_matches_acl_event(self, server_name: str) -> bool: ...

synapse/federation/federation_server.py

@@ -25,17 +25,12 @@
     List,
     Mapping,
     Optional,
-    Pattern,
-    Sequence,
     Tuple,
     Union,
 )
 
-import attr
-from matrix_common.regex import glob_to_regex
 from prometheus_client import Counter, Gauge, Histogram
 
-from twisted.internet.abstract import isIPAddress
 from twisted.python import failure
 
 from synapse.api.constants import (
@@ -89,6 +84,7 @@
 from synapse.storage.databases.main.lock import Lock
 from synapse.storage.databases.main.roommember import extract_heroes_from_room_summary
 from synapse.storage.roommember import MemberSummary
+from synapse.synapse_rust.acl import ServerAclEvaluator
 from synapse.types import JsonDict, StateMap, get_domain_from_id
 from synapse.util import unwrapFirstError
 from synapse.util.async_helpers import Linearizer, concurrently_execute, gather_results
@@ -130,50 +126,6 @@
 _INBOUND_EVENT_HANDLING_LOCK_NAME = "federation_inbound_pdu"
 
 
-@attr.s(slots=True, frozen=True, auto_attribs=True)
-class ServerAclEvaluator:
-    allow_ip_literals: bool
-    allow: Sequence[Pattern[str]]
-    deny: Sequence[Pattern[str]]
-
-    def server_matches_acl_event(self, server_name: str) -> bool:
-        """Check if the given server is allowed by the ACL event
-
-        Args:
-            server_name: name of server, without any port part
-
-        Returns:
-            True if this server is allowed by the ACLs
-        """
-
-        # first of all, check if literal IPs are blocked, and if so, whether the
-        # server name is a literal IP
-        if not self.allow_ip_literals:
-            # check for ipv6 literals. These start with '['.
-            if server_name[0] == "[":
-                return False
-
-            # check for ipv4 literals. We can just lift the routine from twisted.
-            if isIPAddress(server_name):
-                return False
-
-        # next,  check the deny list
-        for e in self.deny:
-            if e.match(server_name):
-                # logger.info("%s matched deny rule %s", server_name, e)
-                return False
-
-        # then the allow list.
-        for e in self.allow:
-            if e.match(server_name):
-                # logger.info("%s matched allow rule %s", server_name, e)
-                return True
-
-        # everything else should be rejected.
-        # logger.info("%s fell through", server_name)
-        return False
-
-
 class FederationServer(FederationBase):
     def __init__(self, hs: "HomeServer"):
         super().__init__(hs)
@@ -1411,15 +1363,15 @@ def server_acl_evaluator_from_event(acl_event: EventBase) -> "ServerAclEvaluator
         logger.warning("Ignoring non-list deny ACL %s", deny)
         deny = []
     else:
-        deny = [glob_to_regex(s) for s in deny if isinstance(s, str)]
+        deny = [s for s in deny if isinstance(s, str)]
 
     # then the allow list.
     allow = acl_event.content.get("allow", [])
     if not isinstance(allow, (list, tuple)):
         logger.warning("Ignoring non-list allow ACL %s", allow)
         allow = []
     else:
-        allow = [glob_to_regex(s) for s in allow if isinstance(s, str)]
+        allow = [s for s in allow if isinstance(s, str)]
 
     return ServerAclEvaluator(allow_ip_literals, allow, deny)