snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/management/commands/fetch_tor_exit_nodes.py

@@ -0,0 +1,75 @@
+import os
+from argparse import ArgumentParser
+from typing import Any
+
+import orjson
+from django.conf import settings
+from typing_extensions import override
+from urllib3.util import Retry
+
+from zerver.lib.management import ZulipBaseCommand, abort_cron_during_deploy, abort_unless_locked
+from zerver.lib.outgoing_http import OutgoingSession
+
+
+class TorDataSession(OutgoingSession):
+    def __init__(self, max_retries: int) -> None:
+        Retry.DEFAULT_BACKOFF_MAX = 64
+        retry = Retry(
+            total=max_retries,
+            backoff_factor=2.0,
+            status_forcelist={  # Retry on these
+                429,  # The formal rate-limiting response code
+                500,  # Server error
+                502,  # Bad gateway
+                503,  # Service unavailable
+            },
+        )
+        super().__init__(role="tor_data", timeout=3, max_retries=retry)
+
+
+class Command(ZulipBaseCommand):
+    help = """Fetch the list of TOR exit nodes, and write the list of IP addresses
+to a file for access from Django for rate-limiting purposes.
+
+Does nothing unless RATE_LIMIT_TOR_TOGETHER is enabled.
+"""
+
+    @override
+    def add_arguments(self, parser: ArgumentParser) -> None:
+        parser.add_argument(
+            "--max-retries",
+            type=int,
+            default=10,
+            help="Number of times to retry fetching data from TOR",
+        )
+
+    @override
+    @abort_cron_during_deploy
+    @abort_unless_locked
+    def handle(self, *args: Any, **options: Any) -> None:
+        if not settings.RATE_LIMIT_TOR_TOGETHER:
+            return
+
+        session = TorDataSession(max_retries=options["max_retries"])
+        response = session.get("https://check.torproject.org/exit-addresses")
+        response.raise_for_status()
+
+        # Format:
+        #     ExitNode 4273E6D162ED2717A1CF4207A254004CD3F5307B
+        #     Published 2021-11-02 11:01:07
+        #     LastStatus 2021-11-02 23:00:00
+        #     ExitAddress 176.10.99.200 2021-11-02 23:17:02
+        exit_nodes: set[str] = set()
+        for line in response.text.splitlines():
+            if line.startswith("ExitAddress "):
+                exit_nodes.add(line.split()[1])
+
+        # Write to a tmpfile to ensure we can't read a partially-written file
+        with open(settings.TOR_EXIT_NODE_FILE_PATH + ".tmp", "wb") as f:
+            f.write(orjson.dumps(list(exit_nodes)))
+
+        # Do an atomic rename into place
+        os.rename(
+            settings.TOR_EXIT_NODE_FILE_PATH + ".tmp",
+            settings.TOR_EXIT_NODE_FILE_PATH,
+        )