asyncio: Fix getaddrinfo to accept service names (for port)

Yury Selivanov · Yury Selivanov · commit a714616d3613 · 2016-06-02T16:51:07.000-04:00
Patch by A. Jesse Jiryu Davis
diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
@@ -102,10 +102,26 @@ def _ipaddr_info(host, port, family, type, proto):
     else:
         return None
 
-    if port in {None, '', b''}:
+    if port is None:
         port = 0
-    elif isinstance(port, (bytes, str)):
-        port = int(port)
+    elif isinstance(port, bytes):
+        if port == b'':
+            port = 0
+        else:
+            try:
+                port = int(port)
+            except ValueError:
+                # Might be a service name like b"http".
+                port = socket.getservbyname(port.decode('ascii'))
+    elif isinstance(port, str):
+        if port == '':
+            port = 0
+        else:
+            try:
+                port = int(port)
+            except ValueError:
+                # Might be a service name like "http".
+                port = socket.getservbyname(port)
 
     if hasattr(socket, 'inet_pton'):
         if family == socket.AF_UNSPEC:
diff --git a/Lib/test/test_asyncio/test_base_events.py b/Lib/test/test_asyncio/test_base_events.py
@@ -146,6 +146,26 @@ def test_port_parameter_types(self):
             (INET, STREAM, TCP, '', ('1.2.3.4', 1)),
             base_events._ipaddr_info('1.2.3.4', b'1', INET, STREAM, TCP))
 
+    def test_getaddrinfo_servname(self):
+        INET = socket.AF_INET
+        STREAM = socket.SOCK_STREAM
+        TCP = socket.IPPROTO_TCP
+
+        self.assertEqual(
+            (INET, STREAM, TCP, '', ('1.2.3.4', 80)),
+            base_events._ipaddr_info('1.2.3.4', 'http', INET, STREAM, TCP))
+
+        self.assertEqual(
+            (INET, STREAM, TCP, '', ('1.2.3.4', 80)),
+            base_events._ipaddr_info('1.2.3.4', b'http', INET, STREAM, TCP))
+
+        # Raises "service/proto not found".
+        with self.assertRaises(OSError):
+            base_events._ipaddr_info('1.2.3.4', 'nonsense', INET, STREAM, TCP)
+
+        with self.assertRaises(OSError):
+            base_events._ipaddr_info('1.2.3.4', 'nonsense', INET, STREAM, TCP)
+
     @patch_socket
     def test_ipaddr_info_no_inet_pton(self, m_socket):
         del m_socket.inet_pton
