server: 修 dns_upstream host:port 解析(此前硬编码 53 致云端 DNS 超时)

channel/server.py

@@ -57,6 +57,16 @@ class CloudConfig:
         self.key_file = str(cert.get("key_file", ""))
 
 
+def _upstream_addr(dns_upstream: str) -> tuple[str, int]:
+    """解析 dns_upstream 的 host:port(缺省 53)。"""
+    h = dns_upstream.strip()
+    if h.count(":") == 1:
+        name, _, port_s = h.rpartition(":")
+        if port_s.isdigit():
+            return name, int(port_s)
+    return h, 53
+
+
 def _denied(host: str, suffixes: list[str]) -> bool:
     low = host.lower()
     for s in suffixes:
@@ -218,7 +228,7 @@ class _ConnThread(threading.Thread):
             up = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
             try:
                 up.settimeout(5)
-                up.sendto(payload, (self.conf.dns_upstream, 53))
+                up.sendto(payload, _upstream_addr(self.conf.dns_upstream))
                 resp, _ = up.recvfrom(4096)
             finally:
                 up.close()

tests/test_httpmsg.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 import unittest
 
 from channel.httpmsg import parse_request, parse_request_head
-from channel.server import _denied, _error_resp
+from channel.server import _denied, _error_resp, _upstream_addr
 
 
 def _get(host: str = "example.com", path: str = "/a?b=1") -> bytes:
@@ -82,6 +82,10 @@ class ServerHelperTest(unittest.TestCase):
         self.assertTrue(resp.startswith(b"HTTP/1.1 502"))
         self.assertIn(b"Content-Length:", resp)
 
+    def test_upstream_addr(self) -> None:
+        self.assertEqual(_upstream_addr("127.0.0.1:5353"), ("127.0.0.1", 5353))
+        self.assertEqual(_upstream_addr("223.5.5.5"), ("223.5.5.5", 53))
+
 
 if __name__ == "__main__":
     unittest.main()