Use localhost as the default bind address (#719)

docs/changelog/v2.0.0.rst

@@ -9,8 +9,8 @@ The major breaking changes with the version 2.0 release are:
   * SOP class variable names now use their `new DICOM UID keywords
     <https://dicom.nema.org/medical/dicom/current/output/chtml/part06/chapter_A.html#table_A-1>`_
     (for example, *VerificationSOPClass* becomes simply *Verification*)
-  * AE titles values should be :class:`str` rather than :class:`bytes` and will no
-    longer contain any trailing padding spaces
+  * AE titles values should be :class:`str` rather than :class:`bytes` and trailing
+    padding spaces are stripped from the raw value during decoding.
 
 
 Fixes
@@ -86,3 +86,5 @@ Changes
   :attr:`~pynetdicom.sop_class.Verification`
 * All AE titles and DIMSE elements with a VR of **AE** should be set using an
   ASCII :class:`str` rather than :class:`bytes`
+* The default bind address used when making association requests changed to
+  ``("localhost", 0)`` (:issue:`680`)

pynetdicom/_globals.py

@@ -98,4 +98,8 @@
 STATUS_UNKNOWN: str = "Unknown"
 
 
+# The default address that client sockets are bound to
+BIND_ADDRESS = ("localhost", 0)
+
+
 OptionalUIDType = Optional[Union[str, bytes, UID]]

pynetdicom/ae.py

@@ -37,6 +37,7 @@
     MODE_REQUESTOR,
     DEFAULT_MAX_LENGTH,
     DEFAULT_TRANSFER_SYNTAXES,
+    BIND_ADDRESS,
 )
 
 
@@ -466,7 +467,7 @@ def associate(
         ae_title: str = "ANY-SCP",
         max_pdu: int = DEFAULT_MAX_LENGTH,
         ext_neg: Optional[List[_UI]] = None,
-        bind_address: Tuple[str, int] = ("", 0),
+        bind_address: Tuple[str, int] = BIND_ADDRESS,
         tls_args: Optional[Tuple[SSLContext, str]] = None,
         evt_handlers: Optional[List[EventHandlerType]] = None,
     ) -> Association:
@@ -493,7 +494,8 @@ def associate(
 
         .. versionchanged:: 2.0
 
-            `ae_title` should now be :class:`str`
+            * `ae_title` should now be :class:`str`
+            * The default `bind_address` was changed to ``("localhost", 0)``
 
         Parameters
         ----------
@@ -524,7 +526,7 @@ def associate(
             * :class:`~UserIdentityNegotiation` (0 or 1 item)
         bind_address : 2-tuple, optional
             The (host, port) to bind the association's communication socket
-            to, default ``('', 0)``.
+            to, default ``("localhost", 0)``.
         tls_args : 2-tuple, optional
             If TLS is required then this should be a 2-tuple containing a
             (`ssl_context`, `server_hostname`), where `ssl_context` is the
@@ -1352,9 +1354,9 @@ def start_server(
 
         Parameters
         ----------
-        address : 2-tuple
-            The (`host`, `port`) to use when listening for incoming association
-            requests.
+        address : Tuple[str, int]
+            The ``(host: str, port: int)`` to use when listening for incoming
+            association requests.
         block : bool, optional
             If ``True`` (default) then the server will be blocking, otherwise
             it will start the server in a new thread and be non-blocking.

pynetdicom/tests/test_ae.py

@@ -588,7 +588,11 @@ def test_connection_timeout(self, caplog):
         scu_ae.connection_timeout = 2
         scu_ae.add_requested_context(Verification)
         with caplog.at_level(logging.ERROR, logger="pynetdicom"):
-            assoc = scu_ae.associate("example.com", 11112)
+            assoc = scu_ae.associate(
+                "example.com",
+                11112,
+                bind_address=("", 0),
+            )
             assert not assoc.is_established
             assert assoc.is_aborted
             msgs = [

pynetdicom/tests/test_fsm.py

@@ -241,7 +241,7 @@ def get_associate(self, assoc_type):
             # Called AE Title is the destination DICOM AE title
             primitive.called_ae_title = "REMOTE_AE_TITLE "
             # The TCP/IP address of the source, pynetdicom includes port too
-            primitive.calling_presentation_address = ("", 0)
+            primitive.calling_presentation_address = ("localhost", 0)
             # The TCP/IP address of the destination, pynetdicom includes port too
             primitive.called_presentation_address = ("localhost", 11112)
             # Proposed presentation contexts

pynetdicom/transport.py

@@ -32,7 +32,7 @@
 )
 
 from pynetdicom import evt, _config
-from pynetdicom._globals import MODE_ACCEPTOR
+from pynetdicom._globals import MODE_ACCEPTOR, BIND_ADDRESS
 from pynetdicom._handlers import (
     standard_dimse_recv_handler,
     standard_dimse_sent_handler,
@@ -74,10 +74,14 @@ def __init__(
         self,
         assoc: "Association",
         client_socket: Optional[socket.socket] = None,
-        address: Tuple[str, int] = ("", 0),
+        address: Tuple[str, int] = BIND_ADDRESS,
     ) -> None:
         """Create a new :class:`AssociationSocket`.
 
+        .. versionchanged:: 2.0
+
+            The default for *address* was changed to ``("localhost", 0)``
+
         Parameters
         ----------
         assoc : association.Association
@@ -89,11 +93,11 @@ def __init__(
         address : 2-tuple, optional
             If *client_socket* is ``None`` then this is the ``(host, port)`` to
             bind the newly created socket to, which by default will be
-            ``('', 0)``.
+            ``('localhost', 0)``.
         """
         self._assoc = assoc
 
-        if client_socket is not None and address != ("", 0):
+        if client_socket is not None and address != BIND_ADDRESS:
             LOGGER.warning(
                 "AssociationSocket instantiated with both a 'client_socket' "
                 "and bind 'address'. The original socket will not be rebound"
@@ -156,7 +160,7 @@ def connect(self, address: Tuple[str, int]) -> None:
         Parameters
         ----------
         address : 2-tuple
-            The ``(host, port)`` IPv4 address to connect to.
+            The ``(host: str, port: int)`` IPv4 address to connect to.
         """
         if self.socket is None:
             self.socket = self._create_socket()
@@ -205,7 +209,7 @@ def connect(self, address: Tuple[str, int]) -> None:
         finally:
             self._ready.set()
 
-    def _create_socket(self, address: Tuple[str, int] = ("", 0)) -> socket.socket:
+    def _create_socket(self, address: Tuple[str, int] = BIND_ADDRESS) -> socket.socket:
         """Create a new IPv4 TCP socket and set it up for use.
 
         *Socket Options*
@@ -217,8 +221,8 @@ def _create_socket(self, address: Tuple[str, int] = ("", 0)) -> socket.socket:
         Parameters
         ----------
         address : 2-tuple, optional
-            The ``(host, port)`` to bind the socket to. By default the socket
-            is bound to ``('', 0)``, i.e. the first available port.
+            The ``(host: str, port: int)`` to bind the socket to. By default the socket
+            is bound to ``("localhost", 0)``, i.e. the first available port.
 
         Returns
         -------
@@ -263,16 +267,16 @@ def get_local_addr(self, host: Tuple[str, int] = ("10.255.255.255", 1)) -> str:
 
         Parameters
         ----------
-        host : str
-            The host's (*addr*, *port*) when trying to determine the local
+        host : Tuple[str, int]
+            The host's ``(addr: str, port: int)`` when trying to determine the local
             address.
         """
         # Solution from https://stackoverflow.com/a/28950776
-        with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as temp:
+        with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as sock:
             try:
                 # We use `host` to allow unit testing
-                temp.connect(host)
-                addr: str = temp.getsockname()[0]
+                sock.connect(host)
+                addr: str = sock.getsockname()[0]
             except:
                 addr = "127.0.0.1"
 
@@ -530,8 +534,8 @@ class AssociationServer(TCPServer):
         The parent AE that is running the server.
     request_queue_size : int
         Default ``5``.
-    server_address : 2-tuple
-        The ``(host, port)`` that the server is running on.
+    server_address : Tuple[str, int]
+        The ``(host: str, port: int)`` that the server is running on.
     """
 
     def __init__(
@@ -551,8 +555,8 @@ def __init__(
         ----------
         ae : ae.ApplicationEntity
             The parent AE that's running the server.
-        address : 2-tuple
-            The ``(host, port)`` that the server should run on.
+        address : Tuple[str, int]
+            The ``(host: str, port: int)`` that the server should run on.
         ae_title : str
             The AE title of the SCP.
         contexts : list of presentation.PresentationContext