[netdata] mechanism to track max Network Data length since start/reset (#8826)

This commit adds new mechanism in `NetworkData::Leader` to track the
the maximum observed length of the Thread Network Data since OT stack
initialization or since the last time user reset the tracking
mechanism by calling `otNetDataResetMaxLength()`. This commit also
adds public OT API and  CLI commands for this.

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (294)
+#define OPENTHREAD_API_VERSION (295)
 
 /**
  * @addtogroup api-instance

include/openthread/netdata.h

@@ -125,7 +125,7 @@ typedef struct otServiceConfig
 } otServiceConfig;
 
 /**
- * This method provides a full or stable copy of the Partition's Thread Network Data.
+ * Provide full or stable copy of the Partition's Thread Network Data.
  *
  * @param[in]      aInstance    A pointer to an OpenThread instance.
  * @param[in]      aStable      TRUE when copying the stable version, FALSE when copying the full version.
@@ -133,11 +133,45 @@ typedef struct otServiceConfig
  * @param[in,out]  aDataLength  On entry, size of the data buffer pointed to by @p aData.
  *                              On exit, number of copied bytes.
  *
+ * @retval OT_ERROR_NONE    Successfully copied the Thread Network Data into @p aData and updated @p aDataLength.
+ * @retval OT_ERROR_NO_BUFS Not enough space in @p aData to fully copy the Thread Network Data.
+ *
  */
 otError otNetDataGet(otInstance *aInstance, bool aStable, uint8_t *aData, uint8_t *aDataLength);
 
 /**
- * This function gets the next On Mesh Prefix in the partition's Network Data.
+ * Get the current length (number of bytes) of Partition's Thread Network Data.
+ *
+ * @param[in] aInstance    A pointer to an OpenThread instance.
+ *
+ * @return The length of the Network Data.
+ *
+ */
+uint8_t otNetDataGetLength(otInstance *aInstance);
+
+/**
+ * Get the maximum observed length of the Thread Network Data since OT stack initialization or since the last call to
+ * `otNetDataResetMaxLength()`.
+ *
+ * @param[in] aInstance    A pointer to an OpenThread instance.
+ *
+ * @return The maximum length of the Network Data (high water mark for Network Data length).
+ *
+ */
+uint8_t otNetDataGetMaxLength(otInstance *aInstance);
+
+/**
+ * Reset the tracked maximum length of the Thread Network Data.
+ *
+ * @param[in] aInstance    A pointer to an OpenThread instance.
+ *
+ * @sa otNetDataGetMaxLength
+ *
+ */
+void otNetDataResetMaxLength(otInstance *aInstance);
+
+/**
+ * Get the next On Mesh Prefix in the partition's Network Data.
  *
  * @param[in]      aInstance  A pointer to an OpenThread instance.
  * @param[in,out]  aIterator  A pointer to the Network Data iterator context. To get the first on-mesh entry
@@ -153,7 +187,7 @@ otError otNetDataGetNextOnMeshPrefix(otInstance            *aInstance,
                                      otBorderRouterConfig  *aConfig);
 
 /**
- * This function gets the next external route in the partition's Network Data.
+ * Get the next external route in the partition's Network Data.
  *
  * @param[in]      aInstance  A pointer to an OpenThread instance.
  * @param[in,out]  aIterator  A pointer to the Network Data iterator context. To get the first external route entry
@@ -167,7 +201,7 @@ otError otNetDataGetNextOnMeshPrefix(otInstance            *aInstance,
 otError otNetDataGetNextRoute(otInstance *aInstance, otNetworkDataIterator *aIterator, otExternalRouteConfig *aConfig);
 
 /**
- * This function gets the next service in the partition's Network Data.
+ * Get the next service in the partition's Network Data.
  *
  * @param[in]      aInstance  A pointer to an OpenThread instance.
  * @param[in,out]  aIterator  A pointer to the Network Data iterator context. To get the first service entry
@@ -231,8 +265,7 @@ otError otNetDataSteeringDataCheckJoinerWithDiscerner(otInstance
                                                       const struct otJoinerDiscerner *aDiscerner);
 
 /**
- * This function checks whether a given Prefix can act as a valid OMR prefix and also the Leader's Network Data contains
- * this prefix.
+ * Check whether a given Prefix can act as a valid OMR prefix and also the Leader's Network Data contains this prefix.
  *
  * @param[in]  aInstance  A pointer to an OpenThread instance.
  * @param[in]  aPrefix    A pointer to the IPv6 prefix.

src/cli/README_NETDATA.md

@@ -142,6 +142,8 @@ After the device successfully attaches to a Thread network, the device will retr
 ## Command List
 
 - [help](#help)
+- [length](#length)
+- [maxlength](#maxlength)
 - [publish](#publish)
 - [register](#register)
 - [show](#show)
@@ -158,7 +160,8 @@ Print netdata help menu.
 
 ```bash
 > netdata help
-help
+length
+maxlength
 publish
 register
 show
@@ -167,6 +170,41 @@ unpublish
 Done
 ```
 
+### length
+
+Usage: `netdata length`
+
+Get the current length of (number of bytes) Partition's Thread Network Data.
+
+```bash
+> netdata length
+23
+Done
+```
+
+### maxlength
+
+Usage: `netdata maxlength`
+
+Get the maximum observed length of the Thread Network Data since OT stack initialization or since the last call to `netdata maxlength reset`.
+
+```bash
+> netdata maxlength
+40
+Done
+```
+
+### maxlength reset
+
+Usage: `netdata maxlength reset`
+
+Reset the tracked maximum length of the Thread Network Data.
+
+```bash
+> netdata maxlength reset
+Done
+```
+
 ### publish
 
 The Network Data Publisher provides mechanisms to limit the number of similar Service and/or Prefix (on-mesh prefix or external route) entries in the Thread Network Data by monitoring the Network Data and managing if or when to add or remove entries.

src/cli/cli_network_data.cpp

@@ -159,6 +159,66 @@ void NetworkData::OutputService(const otServiceConfig &aConfig)
     OutputLine(" %04x", aConfig.mServerConfig.mRloc16);
 }
 
+/**
+ * @cli netdata length
+ * @code
+ * netdata length
+ * 23
+ * Done
+ * @endcode
+ * @par api_copy
+ * #otNetDataGetLength
+ */
+template <> otError NetworkData::Process<Cmd("length")>(Arg aArgs[])
+{
+    otError error = OT_ERROR_NONE;
+
+    VerifyOrExit(aArgs[0].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
+    OutputLine("%u", otNetDataGetLength(GetInstancePtr()));
+
+exit:
+    return error;
+}
+
+template <> otError NetworkData::Process<Cmd("maxlength")>(Arg aArgs[])
+{
+    otError error = OT_ERROR_NONE;
+
+    /**
+     * @cli netdata maxlength
+     * @code
+     * netdata maxlength
+     * 40
+     * Done
+     * @endcode
+     * @par api_copy
+     * #otNetDataGetMaxLength
+     */
+    if (aArgs[0].IsEmpty())
+    {
+        OutputLine("%u", otNetDataGetMaxLength(GetInstancePtr()));
+    }
+    /**
+     * @cli netdata maxlength reset
+     * @code
+     * netdata maxlength reset
+     * Done
+     * @endcode
+     * @par api_copy
+     * #otNetDataResetMaxLength
+     */
+    else if (aArgs[0] == "reset")
+    {
+        otNetDataResetMaxLength(GetInstancePtr());
+    }
+    else
+    {
+        error = OT_ERROR_INVALID_ARGS;
+    }
+
+    return error;
+}
+
 #if OPENTHREAD_CONFIG_NETDATA_PUBLISHER_ENABLE
 template <> otError NetworkData::Process<Cmd("publish")>(Arg aArgs[])
 {
@@ -669,6 +729,8 @@ otError NetworkData::Process(Arg aArgs[])
     }
 
     static constexpr Command kCommands[] = {
+        CmdEntry("length"),
+        CmdEntry("maxlength"),
 #if OPENTHREAD_CONFIG_NETDATA_PUBLISHER_ENABLE
         CmdEntry("publish"),
 #endif
@@ -693,7 +755,8 @@ otError NetworkData::Process(Arg aArgs[])
      * @cli netdata help
      * @code
      * netdata help
-     * help
+     * length
+     * maxlength
      * publish
      * register
      * show

src/core/api/netdata_api.cpp

@@ -49,6 +49,21 @@ otError otNetDataGet(otInstance *aInstance, bool aStable, uint8_t *aData, uint8_
         aStable ? NetworkData::kStableSubset : NetworkData::kFullSet, aData, *aDataLength);
 }
 
+uint8_t otNetDataGetLength(otInstance *aInstance)
+{
+    return AsCoreType(aInstance).Get<NetworkData::Leader>().GetLength();
+}
+
+uint8_t otNetDataGetMaxLength(otInstance *aInstance)
+{
+    return AsCoreType(aInstance).Get<NetworkData::Leader>().GetMaxLength();
+}
+
+void otNetDataResetMaxLength(otInstance *aInstance)
+{
+    AsCoreType(aInstance).Get<NetworkData::Leader>().ResetMaxLength();
+}
+
 otError otNetDataGetNextOnMeshPrefix(otInstance            *aInstance,
                                      otNetworkDataIterator *aIterator,
                                      otBorderRouterConfig  *aConfig)

src/core/thread/network_data_leader.cpp

@@ -60,7 +60,7 @@ void LeaderBase::Reset(void)
     mVersion       = Random::NonCrypto::GetUint8();
     mStableVersion = Random::NonCrypto::GetUint8();
     SetLength(0);
-    Get<ot::Notifier>().Signal(kEventThreadNetdataChanged);
+    SignalNetDataChanged();
 }
 
 Error LeaderBase::GetServiceId(uint32_t           aEnterpriseNumber,
@@ -412,7 +412,7 @@ Error LeaderBase::SetNetworkData(uint8_t        aVersion,
 
     DumpDebg("SetNetworkData", GetBytes(), GetLength());
 
-    Get<ot::Notifier>().Signal(kEventThreadNetdataChanged);
+    SignalNetDataChanged();
 
 exit:
     return error;
@@ -437,7 +437,7 @@ Error LeaderBase::SetCommissioningData(const uint8_t *aValue, uint8_t aValueLeng
     }
 
     mVersion++;
-    Get<ot::Notifier>().Signal(kEventThreadNetdataChanged);
+    SignalNetDataChanged();
 
 exit:
     return error;
@@ -532,5 +532,11 @@ Error LeaderBase::SteeringDataCheckJoiner(const MeshCoP::JoinerDiscerner &aDisce
     return SteeringDataCheck(filterIndexes);
 }
 
+void LeaderBase::SignalNetDataChanged(void)
+{
+    mMaxLength = Max(mMaxLength, GetLength());
+    Get<ot::Notifier>().Signal(kEventThreadNetdataChanged);
+}
+
 } // namespace NetworkData
 } // namespace ot

src/core/thread/network_data_leader.hpp

@@ -74,6 +74,7 @@ public:
      */
     explicit LeaderBase(Instance &aInstance)
         : MutableNetworkData(aInstance, mTlvBuffer, 0, sizeof(mTlvBuffer))
+        , mMaxLength(0)
     {
         Reset();
     }
@@ -84,6 +85,23 @@ public:
      */
     void Reset(void);
 
+    /**
+     * This method returns the maximum observed Network Data length since OT stack initialization or since the last
+     * call to `ResetMaxLength()`.
+     *
+     * @returns The maximum observed Network Data length (high water mark for Network Data length).
+     *
+     */
+    uint8_t GetMaxLength(void) const { return mMaxLength; }
+
+    /**
+     * This method resets the tracked maximum Network Data Length.
+     *
+     * @sa GetMaxLength
+     *
+     */
+    void ResetMaxLength(void) { mMaxLength = GetLength(); }
+
     /**
      * This method returns the Data Version value for a type (full set or stable subset).
      *
@@ -280,6 +298,8 @@ public:
     Error GetPreferredNat64Prefix(ExternalRouteConfig &aConfig) const;
 
 protected:
+    void SignalNetDataChanged(void);
+
     uint8_t mStableVersion;
     uint8_t mVersion;
 
@@ -302,6 +322,7 @@ private:
     void  GetContextForMeshLocalPrefix(Lowpan::Context &aContext) const;
 
     uint8_t mTlvBuffer[kMaxSize];
+    uint8_t mMaxLength;
 };
 
 /**

src/core/thread/network_data_leader_ftd.cpp

@@ -117,7 +117,7 @@ void Leader::IncrementVersions(bool aIncludeStable)
     }
 
     mVersion++;
-    Get<ot::Notifier>().Signal(kEventThreadNetdataChanged);
+    SignalNetDataChanged();
 }
 
 void Leader::RemoveBorderRouter(uint16_t aRloc16, MatchMode aMatchMode)