Add ability for chip-repl to grab MaxPathsPerInvoke of remote node (#30880)

* Add ability for chip-repl to grab MaxPathsPerInvoke of remote node

* Fix CI

* Address PR comments

* Restyle

* Address PR comments

* Address PR comments

Author: tehampson

src/controller/python/chip/ChipDeviceCtrl.py

@@ -53,7 +53,7 @@
 from .clusters.CHIPClusters import ChipClusters
 from .crypto import p256keypair
 from .exceptions import UnknownAttribute, UnknownCommand
-from .interaction_model import InteractionModelError
+from .interaction_model import InteractionModelError, SessionParameters, SessionParametersStruct
 from .interaction_model import delegate as im
 from .native import PyChipError
 
@@ -809,6 +809,36 @@ def ComputeRoundTripTimeout(self, nodeid, upperLayerProcessingTimeoutMs: int = 0
             device.deviceProxy, upperLayerProcessingTimeoutMs))
         return res
 
+    def GetRemoteSessionParameters(self, nodeid) -> typing.Optional[SessionParameters]:
+        ''' Returns the SessionParameters of reported by the remote node associated with `nodeid`.
+            If there is some error in getting SessionParameters None is returned.
+
+            This will result in a session being established if one wasn't already established.
+        '''
+
+        # First creating the struct to make building the ByteArray to be sent to CFFI easier.
+        sessionParametersStruct = SessionParametersStruct.parse(b'\x00' * SessionParametersStruct.sizeof())
+        sessionParametersByteArray = SessionParametersStruct.build(sessionParametersStruct)
+        device = self.GetConnectedDeviceSync(nodeid)
+        res = self._ChipStack.Call(lambda: self._dmLib.pychip_DeviceProxy_GetRemoteSessionParameters(
+            device.deviceProxy, ctypes.c_char_p(sessionParametersByteArray)))
+
+        # 0 is CHIP_NO_ERROR
+        if res != 0:
+            return None
+
+        sessionParametersStruct = SessionParametersStruct.parse(sessionParametersByteArray)
+        return SessionParameters(
+            sessionIdleInterval=sessionParametersStruct.SessionIdleInterval if sessionParametersStruct.SessionIdleInterval != 0 else None,
+            sessionActiveInterval=sessionParametersStruct.SessionActiveInterval if sessionParametersStruct.SessionActiveInterval != 0 else None,
+            sessionActiveThreshold=sessionParametersStruct.SessionActiveThreshold if sessionParametersStruct.SessionActiveThreshold != 0 else None,
+            dataModelRevision=sessionParametersStruct.DataModelRevision if sessionParametersStruct.DataModelRevision != 0 else None,
+            interactionModelRevision=sessionParametersStruct.InteractionModelRevision if sessionParametersStruct.InteractionModelRevision != 0 else None,
+            specficiationVersion=sessionParametersStruct.SpecificationVersion if sessionParametersStruct.SpecificationVersion != 0 else None,
+            maxPathsPerInvoke=sessionParametersStruct.MaxPathsPerInvoke)
+
+        return res
+
     async def TestOnlySendCommandTimedRequestFlagWithNoTimedInvoke(self, nodeid: int, endpoint: int,
                                                                    payload: ClusterObjects.ClusterCommand, responseType=None):
         '''

src/controller/python/chip/interaction_model/__init__.py

@@ -26,10 +26,12 @@
 
 from chip.exceptions import ChipStackException
 
-from .delegate import AttributePath, AttributePathIBstruct, DataVersionFilterIBstruct, EventPath, EventPathIBstruct
+from .delegate import (AttributePath, AttributePathIBstruct, DataVersionFilterIBstruct, EventPath, EventPathIBstruct,
+                       SessionParameters, SessionParametersStruct)
 
 __all__ = ["AttributePath", "AttributePathIBstruct", "DataVersionFilterIBstruct",
-           "EventPath", "EventPathIBstruct", "Status", "InteractionModelError"]
+           "EventPath", "EventPathIBstruct", "InteractionModelError",
+           "SessionParameters", "SessionParametersStruct", "Status"]
 
 
 # defined src/controller/python/chip/interaction_model/Delegate.h

src/controller/python/chip/interaction_model/delegate.py

@@ -69,6 +69,16 @@
     "DataVersion" / Int32ul,
 )
 
+SessionParametersStruct = Struct(
+    "SessionIdleInterval" / Int32ul,
+    "SessionActiveInterval" / Int32ul,
+    "SessionActiveThreshold" / Int16ul,
+    "DataModelRevision" / Int16ul,
+    "InteractionModelRevision" / Int16ul,
+    "SpecificationVersion" / Int32ul,
+    "MaxPathsPerInvoke" / Int16ul,
+)
+
 
 @dataclass
 class AttributePath:
@@ -107,6 +117,17 @@ class AttributeWriteResult:
     status: int
 
 
+@dataclass
+class SessionParameters:
+    sessionIdleInterval: typing.Optional[int]
+    sessionActiveInterval: typing.Optional[int]
+    sessionActiveThreshold: typing.Optional[int]
+    dataModelRevision: typing.Optional[int]
+    interactionModelRevision: typing.Optional[int]
+    specficiationVersion: typing.Optional[int]
+    maxPathsPerInvoke: int
+
+
 # typedef void (*PythonInteractionModelDelegate_OnCommandResponseStatusCodeReceivedFunct)(uint64_t commandSenderPtr,
 #                                                                                         void * commandStatusBuf);
 # typedef void (*PythonInteractionModelDelegate_OnCommandResponseProtocolErrorFunct)(uint64_t commandSenderPtr,

src/controller/python/chip/utils/DeviceProxyUtils.cpp

@@ -33,6 +33,21 @@
 
 using namespace chip;
 
+namespace python {
+
+struct __attribute__((packed)) SessionParametersStruct
+{
+    uint32_t sessionIdleInterval      = 0;
+    uint32_t sessionActiveInterval    = 0;
+    uint16_t sessionActiveThreshold   = 0;
+    uint16_t dataModelRevision        = 0;
+    uint16_t interactionModelRevision = 0;
+    uint32_t specificationVersion     = 0;
+    uint16_t maxPathsPerInvoke        = 0;
+};
+
+} // namespace python
+
 extern "C" {
 
 /**
@@ -59,4 +74,31 @@ uint32_t pychip_DeviceProxy_ComputeRoundTripTimeout(DeviceProxy * device, uint32
         ->ComputeRoundTripTimeout(System::Clock::Milliseconds32(upperLayerProcessingTimeoutMs))
         .count();
 }
+
+/**
+ * @brief This gets the Session Parameters reported by remote node.
+ *
+ * A valid DeviceProxy pointer with a valid established session is required for this method.
+ */
+PyChipError pychip_DeviceProxy_GetRemoteSessionParameters(DeviceProxy * device, void * sessionParametersStructPointer)
+{
+    VerifyOrReturnError(device != nullptr || sessionParametersStructPointer, ToPyChipError(CHIP_ERROR_INVALID_ARGUMENT));
+
+    auto * deviceProxy = static_cast<DeviceProxy *>(device);
+    VerifyOrReturnError(deviceProxy->GetSecureSession().HasValue(), ToPyChipError(CHIP_ERROR_INCORRECT_STATE));
+
+    auto remoteSessionParameters = deviceProxy->GetSecureSession().Value()->GetRemoteSessionParameters();
+    auto remoteMrpConfig         = remoteSessionParameters.GetMRPConfig();
+
+    python::SessionParametersStruct * sessionParam = static_cast<python::SessionParametersStruct *>(sessionParametersStructPointer);
+
+    sessionParam->sessionIdleInterval      = remoteMrpConfig.mIdleRetransTimeout.count();
+    sessionParam->sessionActiveInterval    = remoteMrpConfig.mActiveRetransTimeout.count();
+    sessionParam->sessionActiveThreshold   = remoteMrpConfig.mActiveThresholdTime.count();
+    sessionParam->dataModelRevision        = remoteSessionParameters.GetDataModelRevision().ValueOr(0);
+    sessionParam->interactionModelRevision = remoteSessionParameters.GetInteractionModelRevision().ValueOr(0);
+    sessionParam->specificationVersion     = remoteSessionParameters.GetSpecificationVersion().ValueOr(0);
+    sessionParam->maxPathsPerInvoke        = remoteSessionParameters.GetMaxPathsPerInvoke();
+    return ToPyChipError(CHIP_NO_ERROR);
+}
 }