Replace Tornado with asyncio (#45)

Author: kgaughan

pyproject.toml

@@ -30,8 +30,6 @@ classifiers = [
   "Topic :: System :: Networking",
 ]
 dependencies = [
-  "netaddr>=1.3.0",
-  "tornado>=6.4.1",
   "beautifulsoup4>=4.12.3",
   "requests>=2.32.3",
 ]
@@ -119,11 +117,12 @@ ignore = [
   "PLW2901",
   "S310",
   "S317",
-  "T201",  # Allow print
+  "T201",    # Allow print
   "TID252",
   "UP006",
   "UP035",
   "EM101",
+  "N817",
 ]
 
 [tool.ruff.lint.isort]

requirements-dev.lock

@@ -188,7 +188,7 @@ coverage==7.6.1 \
     --hash=sha256:fc5a77d0c516700ebad189b587de289a20a78324bc54baee03dd486f0855d234 \
     --hash=sha256:fd21f6ae3f08b41004dfb433fa895d858f3f5979e7762d052b12aef444e29afc
     # via pytest-cov
-exceptiongroup==1.2.2 ; python_version < '3.11' \
+exceptiongroup==1.2.2 ; python_full_version < '3.11' \
     --hash=sha256:3111b9d131c238bec2f8f516e123e14ba243563fb135d3fe885990585aa7795b \
     --hash=sha256:47c2edf7c6738fafb49fd34290706d1a1a2f4d1c6df275526b62cbb4aa5393cc
     # via pytest
@@ -232,10 +232,6 @@ mypy-extensions==1.0.0 \
     --hash=sha256:4392f6c0eb8a5668a69e23d168ffa70f0be9ccfd32b5cc2d26a34ae5b844552d \
     --hash=sha256:75dbf8955dc00442a438fc4d0666508a9a97b6bd41aa2f0ffe9d2f2725af0782
     # via mypy
-netaddr==1.3.0 \
-    --hash=sha256:5c3c3d9895b551b763779ba7db7a03487dc1f8e3b385af819af341ae9ef6e48a \
-    --hash=sha256:c2c6a8ebe5554ce33b7d5b3a306b71bbb373e000bbbf2350dd5213cc56e3dbbe
-    # via uwhoisd
 packaging==24.1 \
     --hash=sha256:026ed72c8ed3fcce5bf8950572258698927fd1dbda10a5e981cdf0ac37f4f002 \
     --hash=sha256:5b8f2217dbdbd2f7f384c41c628544e6d52f2d0f53c6d0c3ea61aa5d1d7ff124
@@ -259,25 +255,12 @@ soupsieve==2.6 \
     --hash=sha256:e2e68417777af359ec65daac1057404a3c8a5455bb8abc36f1a9866ab1a51abb \
     --hash=sha256:e72c4ff06e4fb6e4b5a9f0f55fe6e81514581fca1515028625d0f299c602ccc9
     # via beautifulsoup4
-tomli==2.0.1 ; python_full_version <= '3.11.0a6' or python_version < '3.11' \
+tomli==2.0.1 ; python_full_version <= '3.11' \
     --hash=sha256:939de3e7a6161af0c887ef91b7d41a53e7c5a1ca976325f429cb46ea9bc30ecc \
     --hash=sha256:de526c12914f0c550d15924c62d72abc48d6fe7364aa87328337a31007fe8a4f
     # via coverage
     # via mypy
     # via pytest
-tornado==6.4.1 \
-    --hash=sha256:163b0aafc8e23d8cdc3c9dfb24c5368af84a81e3364745ccb4427669bf84aec8 \
-    --hash=sha256:25486eb223babe3eed4b8aecbac33b37e3dd6d776bc730ca14e1bf93888b979f \
-    --hash=sha256:454db8a7ecfcf2ff6042dde58404164d969b6f5d58b926da15e6b23817950fc4 \
-    --hash=sha256:613bf4ddf5c7a95509218b149b555621497a6cc0d46ac341b30bd9ec19eac7f3 \
-    --hash=sha256:6d5ce3437e18a2b66fbadb183c1d3364fb03f2be71299e7d10dbeeb69f4b2a14 \
-    --hash=sha256:8ae50a504a740365267b2a8d1a90c9fbc86b780a39170feca9bcc1787ff80842 \
-    --hash=sha256:92d3ab53183d8c50f8204a51e6f91d18a15d5ef261e84d452800d4ff6fc504e9 \
-    --hash=sha256:a02a08cc7a9314b006f653ce40483b9b3c12cda222d6a46d4ac63bb6c9057698 \
-    --hash=sha256:b24b8982ed444378d7f21d563f4180a2de31ced9d8d84443907a0a64da2072e7 \
-    --hash=sha256:d9a566c40b89757c9aa8e6f032bcdb8ca8795d7c1a9762910c722b1635c9de4d \
-    --hash=sha256:e2e20b9113cd7293f164dc46fffb13535266e713cdb87bd2d15ddb336e96cfc4
-    # via uwhoisd
 types-beautifulsoup4==4.12.0.20240511 \
     --hash=sha256:004f6096fdd83b19cdbf6cb10e4eae57b10205eccc365d0a69d77da836012e28 \
     --hash=sha256:7ceda66a93ba28d759d5046d7fec9f4cad2f563a77b3a789efc90bcadafeefd1

requirements.lock

@@ -114,10 +114,6 @@ idna==3.7 \
     --hash=sha256:028ff3aadf0609c1fd278d8ea3089299412a7a8b9bd005dd08b9f8285bcb5cfc \
     --hash=sha256:82fee1fc78add43492d3a1898bfa6d8a904cc97d8427f683ed8e798d07761aa0
     # via requests
-netaddr==1.3.0 \
-    --hash=sha256:5c3c3d9895b551b763779ba7db7a03487dc1f8e3b385af819af341ae9ef6e48a \
-    --hash=sha256:c2c6a8ebe5554ce33b7d5b3a306b71bbb373e000bbbf2350dd5213cc56e3dbbe
-    # via uwhoisd
 requests==2.32.3 \
     --hash=sha256:55365417734eb18255590a9ff9eb97e9e1da868d4ccd6402399eaf68af20a760 \
     --hash=sha256:70761cfe03c773ceb22aa2f671b4757976145175cdfca038c02654d061d6dcc6
@@ -126,19 +122,6 @@ soupsieve==2.6 \
     --hash=sha256:e2e68417777af359ec65daac1057404a3c8a5455bb8abc36f1a9866ab1a51abb \
     --hash=sha256:e72c4ff06e4fb6e4b5a9f0f55fe6e81514581fca1515028625d0f299c602ccc9
     # via beautifulsoup4
-tornado==6.4.1 \
-    --hash=sha256:163b0aafc8e23d8cdc3c9dfb24c5368af84a81e3364745ccb4427669bf84aec8 \
-    --hash=sha256:25486eb223babe3eed4b8aecbac33b37e3dd6d776bc730ca14e1bf93888b979f \
-    --hash=sha256:454db8a7ecfcf2ff6042dde58404164d969b6f5d58b926da15e6b23817950fc4 \
-    --hash=sha256:613bf4ddf5c7a95509218b149b555621497a6cc0d46ac341b30bd9ec19eac7f3 \
-    --hash=sha256:6d5ce3437e18a2b66fbadb183c1d3364fb03f2be71299e7d10dbeeb69f4b2a14 \
-    --hash=sha256:8ae50a504a740365267b2a8d1a90c9fbc86b780a39170feca9bcc1787ff80842 \
-    --hash=sha256:92d3ab53183d8c50f8204a51e6f91d18a15d5ef261e84d452800d4ff6fc504e9 \
-    --hash=sha256:a02a08cc7a9314b006f653ce40483b9b3c12cda222d6a46d4ac63bb6c9057698 \
-    --hash=sha256:b24b8982ed444378d7f21d563f4180a2de31ced9d8d84443907a0a64da2072e7 \
-    --hash=sha256:d9a566c40b89757c9aa8e6f032bcdb8ca8795d7c1a9762910c722b1635c9de4d \
-    --hash=sha256:e2e20b9113cd7293f164dc46fffb13535266e713cdb87bd2d15ddb336e96cfc4
-    # via uwhoisd
 urllib3==2.2.2 \
     --hash=sha256:a448b2f64d686155468037e1ace9f2d2199776e17f0a46610480d311f73e3472 \
     --hash=sha256:dd505485549a7a552833da5e6063639d0d177c04f23bc3864e41e5dc5f612168

src/uwhoisd/__init__.py

@@ -2,6 +2,7 @@
 A 'universal' WHOIS proxy server.
 """
 
+import asyncio
 import configparser
 import logging
 import logging.config
@@ -10,7 +11,7 @@
 import socket
 import sys
 
-from . import caching, net, utils
+from . import caching, client, server, utils
 
 USAGE = "Usage: %s <config>"
 
@@ -90,7 +91,7 @@ def get_prefix(self, zone):
         """
         return self.prefixes[zone] if zone in self.prefixes else ""
 
-    def whois(self, query):
+    async def whois(self, query: str) -> str:
         """
         Query the appropriate WHOIS server.
         """
@@ -103,9 +104,8 @@ def whois(self, query):
 
         # Query the registry's WHOIS server.
         server, port = self.get_whois_server(zone)
-        with net.WhoisClient(server, port) as client:
-            logger.info("Querying %s about %s", server, query)
-            response = client.whois(self.get_prefix(zone) + query)
+        logger.info("Querying %s about %s", server, query)
+        response = await client.query_whois(server, port, self.get_prefix(zone) + query)
 
         # Thin registry? Query the registrar's WHOIS server.
         if zone in self.recursion_patterns:
@@ -116,9 +116,8 @@ def whois(self, query):
                 elif self.page_feed:
                     # A form feed character so it's possible to find the split.
                     response += "\f"
-                with net.WhoisClient(server, port) as client:
-                    logger.info("Recursive query to %s about %s", server, query)
-                    response += client.whois(query)
+                logger.info("Recursive query to %s about %s", server, query)
+                response += await client.query_whois(server, port, query)
 
         return response
 
@@ -150,9 +149,12 @@ def main():
         logger.exception("Could not parse config file")
         return 1
     else:
-        net.start_service(iface, port, whois)
+        asyncio.run(server.start_service(iface, port, whois))
         return 0
 
 
 if __name__ == "__main__":
-    sys.exit(main())
+    try:
+        sys.exit(main())
+    except KeyboardInterrupt:
+        pass

src/uwhoisd/caching.py

@@ -40,10 +40,10 @@ def wrap_whois(cache, whois_func):
     if cache is None:
         return whois_func
 
-    def wrapped(query):
+    async def wrapped(query):
         response = cache.get(query)
         if response is None:
-            response = whois_func(query)
+            response = await whois_func(query)
             cache.set(query, response)
         else:
             logger.info("Cache hit for '%s'", query)
@@ -52,21 +52,19 @@ def wrapped(query):
     return wrapped
 
 
-# pylint: disable-msg=R0924
 class LFU:
-    """
-    A simple LFU cache.
+    """A simple LFU cache.
+
+    The eviction queue contains 2-tuples consisting of the time the item was
+    put into the cache and the cache key. The cache maps cache keys onto
+    2-tuples consisting of a counter giving the number of times this item
+    occurs on the eviction queue and the value.
+
     """
 
-    # This is implemented as an LFU cache. The eviction queue contains
-    # 2-tuples consisting of the time the item was put into the cache and the
-    # cache key. The cache maps cache keys onto 2-tuples consisting of a
-    # counter giving the number of times this item occurs on the eviction queue
-    # and the value.
-    #
-    # I may end up reimplementing this as an LRU cache if it turns out that's
-    # more apt, but I haven't went that route as an LRU cache is somewhat more
-    # awkward and involved to implement correctly.
+    # I may end up reimplementing an LRU cache if it turns out that's more apt,
+    # but I haven't went that route as an LRU cache is somewhat more awkward
+    # and involved to implement correctly.
 
     __slots__ = ("cache", "max_age", "max_size", "queue")
 

src/uwhoisd/client.py

@@ -0,0 +1,17 @@
+"""Client."""
+
+import asyncio
+
+
+async def query_whois(host: str, port: int, query: str) -> str:
+    reader, writer = await asyncio.open_connection(host, port)
+
+    writer.write(f"{query}\r\n".encode())
+    await writer.drain()
+
+    response = await asyncio.wait_for(reader.read(), timeout=5)
+
+    writer.close()
+    await writer.wait_closed()
+
+    return str(response, "utf-8", "ignore")

src/uwhoisd/net.py

@@ -8,7 +8,7 @@
 import sys
 import typing as t
 from urllib.parse import urljoin
-import xml.etree.ElementTree as etree  # noqa: N813
+import xml.etree.ElementTree as ET
 
 from bs4 import BeautifulSoup
 import requests
@@ -28,7 +28,7 @@ def fetch_ipv4_assignments(url: str):
     Fetch WHOIS server list for the IPv4 /8 assignments from IANA.
     """
     res = requests.get(url, stream=False, timeout=10)
-    root = etree.fromstring(res.text)  # noqa: S314
+    root = ET.fromstring(res.text)  # noqa: S314
     for record in root.findall("assignments:record", NSS):
         status = record.findtext("assignments:status", default="", namespaces=NSS)
         if status not in ("ALLOCATED", "LEGACY"):

src/uwhoisd/scraper.py

@@ -0,0 +1,30 @@
+import asyncio
+
+from . import utils
+
+
+async def start_service(iface: str, port: int, whois):
+    async def handle_request(reader: asyncio.StreamReader, writer: asyncio.StreamWriter):
+        try:
+            query = await asyncio.wait_for(reader.readuntil(b"\r\n"), timeout=5)
+        except asyncio.TimeoutError:
+            writer.write(b"; Query timeout: closing\r\n")
+            await writer.drain()
+            writer.close()
+            return
+
+        cleaned = query.decode().strip().lower()
+        if not utils.is_well_formed_fqdn(cleaned):
+            result = f"; Bad query: '{cleaned}'\r\n"
+        else:
+            try:
+                result = await whois(cleaned)
+            except asyncio.TimeoutError:
+                result = "; Timeout from upstream server\r\n"
+        writer.write(result.encode())
+        await writer.drain()
+        writer.close()
+
+    svr = await asyncio.start_server(handle_request, host=iface, port=port)
+    async with svr:
+        await svr.serve_forever()