[WIP] Moving Cyphal/UDP to multicast

CHANGELOG.rst

@@ -3,6 +3,12 @@
 Changelog
 =========
 
+v1.13
+-----
+
+- Cyphal/UDP: Service transfer are also multicast now. Make sure to take into account the updated IP mapping specifications.
+  See (`post <https://forum.opencyphal.org/t/cyphal-udp-architectural-issues-caused-by-the-dependency-between-the-nodes-ip-address-and-its-identity/1765>`_).
+
 v1.12
 -----
 

docs/pages/demo.rst

@@ -101,7 +101,7 @@ We can resolve this by passing the correct register values via environment varia
 ..  code-block:: sh
 
     export UAVCAN__NODE__ID=42                           # Set the local node-ID 42 (anonymous by default)
-    export UAVCAN__UDP__IFACE=127.9.0.0                  # Use Cyphal/UDP transport via 127.9.0.42 (sic!)
+    export UAVCAN__UDP__IFACE=127.0.0.1                  # Use Cyphal/UDP transport via localhost
     export UAVCAN__SUB__TEMPERATURE_SETPOINT__ID=2345    # Subject "temperature_setpoint"    on ID 2345
     export UAVCAN__SUB__TEMPERATURE_MEASUREMENT__ID=2346 # Subject "temperature_measurement" on ID 2346
     export UAVCAN__PUB__HEATER_VOLTAGE__ID=2347          # Subject "heater_voltage"          on ID 2347
@@ -114,17 +114,6 @@ The snippet is valid for sh/bash/zsh; if you are using PowerShell on Windows, re
 and take values into double quotes.
 Further snippets will not include this remark.
 
-.. tip:: macOS loopback addresses
-
-    macOS does not properly adhere to RFC3330 such that you will need to manually create aliases for each
-    iface + node-ID used.
-    In our example, with iface being ``127.9.0.0`` and node-ID being ``42`` this would be
-    ``sudo ifconfig lo0 alias 127.9.0.42 up``
-    (see `this <https://superuser.com/questions/458875>`_ superuser article for more details).
-
-    If you come across ``InvalidMediaConfigurationError`` that usually means you haven't set the right alias,
-    you can verify this using ``ifconfig``.
-
 An environment variable ``UAVCAN__SUB__TEMPERATURE_SETPOINT__ID`` sets register ``uavcan.sub.temperature_setpoint.id``,
 and so on.
 
@@ -183,35 +172,35 @@ If you decided to change the working directory or move the compilation outputs,
 make sure to export the ``YAKUT_PATH`` environment variable pointing to the correct location.
 
 The commands shown later need to operate on the same network as the demo.
-Earlier we configured the demo to use Cyphal/UDP via 127.9.0.42.
+Earlier we configured the demo to use Cyphal/UDP via the localhost interface.
 So, for Yakut, we can export this configuration to let it run on the same network anonymously:
 
 ..  code-block:: sh
 
-    export UAVCAN__UDP__IFACE=127.9.0.0  # We don't export the node-ID, so it will remain anonymous.
+    export UAVCAN__UDP__IFACE=127.0.0.1  # We don't export the node-ID, so it will remain anonymous.
 
 To listen to the demo's heartbeat and diagnostics,
 launch the following in a new terminal and leave it running (``y`` is a convenience shortcut for ``yakut``):
 
 ..  code-block:: sh
 
-    export UAVCAN__UDP__IFACE=127.9.0.0
+    export UAVCAN__UDP__IFACE=127.0.0.1
     y sub --with-metadata uavcan.node.heartbeat uavcan.diagnostic.record    # You should see heartbeats
 
 Now let's see how the simple thermostat node is operating.
 Launch another subscriber to see the published voltage command (it is not going to print anything yet):
 
 ..  code-block:: sh
 
-    export UAVCAN__UDP__IFACE=127.9.0.0
+    export UAVCAN__UDP__IFACE=127.0.0.1
     y sub 2347:uavcan.si.unit.voltage.scalar --redraw       # Prints nothing.
 
 And publish the setpoint along with the measurement (process variable):
 
 ..  code-block:: sh
 
-    export UAVCAN__UDP__IFACE=127.9.0.0
-    export UAVCAN__NODE__ID=111         # We need a node-ID to publish messages
+    export UAVCAN__UDP__IFACE=127.0.0.1
+    export UAVCAN__NODE__ID=111         # We need a node-ID to publish messages properly
     y pub --count=10 2345:uavcan.si.unit.temperature.scalar   250 \
                      2346:uavcan.si.sample.temperature.scalar 'kelvin: 240'
 

pycyphal/_version.py

@@ -1 +1 @@
-__version__ = "1.12.1"
+__version__ = "1.13.0"

pycyphal/application/__init__.py

@@ -196,7 +196,7 @@
     >>> os.environ["UAVCAN__NODE__ID"]                   = "42"
     >>> os.environ["UAVCAN__PUB__MEASURED_VOLTAGE__ID"]  = "6543"
     >>> os.environ["UAVCAN__SUB__OPTIONAL_PORT__ID"]     = "65535"
-    >>> os.environ["UAVCAN__UDP__IFACE"]                 = "127.63.0.0"
+    >>> os.environ["UAVCAN__UDP__IFACE"]                 = "127.0.0.1"
     >>> os.environ["UAVCAN__SERIAL__IFACE"]              = "socket://127.0.0.1:50905"
     >>> os.environ["UAVCAN__DIAGNOSTIC__SEVERITY"]       = "3.1"
     >>> os.environ["M__MOTOR__INDUCTANCE_DQ"]            = "0.12 0.13"
@@ -208,15 +208,15 @@
 UAVCAN__NODE__ID                         42
 UAVCAN__PUB__MEASURED_VOLTAGE__ID        6543
 UAVCAN__SUB__OPTIONAL_PORT__ID           65535
-UAVCAN__UDP__IFACE                       127.63.0.0
+UAVCAN__UDP__IFACE                       127.0.0.1
 UAVCAN__SERIAL__IFACE                    socket://127.0.0.1:50905
 UAVCAN__DIAGNOSTIC__SEVERITY             3.1
 M__MOTOR__INDUCTANCE_DQ                  0.12 0.13
 >>> node = pycyphal.application.make_node(node_info, "registers.db")  # The file will be created if doesn't exist.
 >>> node.id
 42
 >>> node.presentation.transport     # Heterogeneously redundant transport: UDP+Serial, as specified in env vars.
-RedundantTransport(UDPTransport('127.63.0.42', ...), SerialTransport('socket://127.0.0.1:50905', ...))
+RedundantTransport(UDPTransport('127.0.0.1', local_node_id=42, ...), SerialTransport('socket://127.0.0.1:50905', ...))
 >>> pub_voltage = node.make_publisher(uavcan.si.unit.voltage.Scalar_1, "measured_voltage")
 >>> pub_voltage.port_id
 6543

pycyphal/application/_transport_factory.py

@@ -154,16 +154,16 @@ def make_transport(
 
     >>> from pycyphal.application.register import ValueProxy, Natural16, Natural32
     >>> reg = {
-    ...     "uavcan.udp.iface": ValueProxy("127.99.0.0"),
+    ...     "uavcan.udp.iface": ValueProxy("127.0.0.1"),
     ...     "uavcan.node.id": ValueProxy(Natural16([257])),
     ... }
     >>> tr = make_transport(reg)
     >>> tr
-    UDPTransport('127.99.1.1', local_node_id=257, ...)
+    UDPTransport('127.0.0.1', local_node_id=257, ...)
     >>> tr.close()
     >>> tr = make_transport(reg, reconfigurable=True)                   # Same but reconfigurable.
     >>> tr                                                              # Wrapped into RedundantTransport.
-    RedundantTransport(UDPTransport('127.99.1.1', local_node_id=257, ...))
+    RedundantTransport(UDPTransport('127.0.0.1', local_node_id=257, ...))
     >>> tr.close()
 
     >>> int(reg["uavcan.udp.mtu"])      # Defaults created automatically to expose all configurables.

pycyphal/presentation/_port/_client.py

@@ -356,6 +356,8 @@ async def _task_function(self) -> None:
                         fut.set_result((response, transfer))
         except asyncio.CancelledError:
             _logger.debug("Cancelling the task of %s", self)
+        except pycyphal.transport.ResourceClosedError as ex:
+            _logger.debug("Cancelling the task of %s because the underlying resource is closed: %s", self, ex)
         except Exception as ex:
             exception = ex
             # Do not use f-string because it can throw, unlike the built-in formatting facility of the logger

pycyphal/transport/_data_specifier.py

@@ -23,7 +23,7 @@ class MessageDataSpecifier(DataSpecifier):
 
     def __post_init__(self) -> None:
         if not (0 <= self.subject_id <= self.SUBJECT_ID_MASK):
-            raise ValueError(f"Invalid subject ID: {self.subject_id}")
+            raise ValueError(f"Invalid subject-ID: {self.subject_id}")
 
 
 @dataclasses.dataclass(frozen=True)