From fe0037e67a2456f24c459e3b51bb92d4a74a6f08 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Tue, 11 Jun 2024 08:45:11 -0700
Subject: [PATCH] [mle] add `Mle::RxMessage::ReadAndSetNetworkDataTlv()`
 (#10358)

This commit adds `ReadAndSetNetworkDataTlv()` to `Mle::RxMessage` to
read the Network Data TLV from a received MLE message and set it in
`NetworkData::Leader`.
---
 src/core/thread/mle.cpp | 43 ++++++++++++++++++++++++-----------------
 src/core/thread/mle.hpp |  1 +
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index 838ff8ef2..b45d07529 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -2902,8 +2902,6 @@ Error Mle::HandleLeaderData(RxInfo &aRxInfo)
     bool               saveActiveDataset  = false;
     bool               savePendingDataset = false;
     bool               dataRequest        = false;
-    uint16_t           offset;
-    uint16_t           length;
 
     SuccessOrExit(error = aRxInfo.mMessage.ReadLeaderDataTlv(leaderData));
 
@@ -2977,16 +2975,15 @@ Error Mle::HandleLeaderData(RxInfo &aRxInfo)
         ExitNow(error = kErrorParse);
     }
 
-    if (Tlv::FindTlvValueOffset(aRxInfo.mMessage, Tlv::kNetworkData, offset, length) == kErrorNone)
+    switch (error = aRxInfo.mMessage.ReadAndSetNetworkDataTlv(leaderData))
     {
-        error = Get<NetworkData::Leader>().SetNetworkData(leaderData.GetDataVersion(NetworkData::kFullSet),
-                                                          leaderData.GetDataVersion(NetworkData::kStableSubset),
-                                                          GetNetworkDataType(), aRxInfo.mMessage, offset, length);
-        SuccessOrExit(error);
-    }
-    else
-    {
-        ExitNow(dataRequest = true);
+    case kErrorNone:
+        break;
+    case kErrorNotFound:
+        dataRequest = true;
+        OT_FALL_THROUGH;
+    default:
+        ExitNow();
     }
 
 #if OPENTHREAD_FTD
@@ -3308,8 +3305,6 @@ void Mle::HandleChildIdResponse(RxInfo &aRxInfo)
     uint16_t           sourceAddress;
     uint16_t           shortAddress;
     MeshCoP::Timestamp timestamp;
-    uint16_t           networkDataOffset;
-    uint16_t           networkDataLength;
 
     SuccessOrExit(error = Tlv::Find<SourceAddressTlv>(aRxInfo.mMessage, sourceAddress));
 
@@ -3324,8 +3319,7 @@ void Mle::HandleChildIdResponse(RxInfo &aRxInfo)
 
     SuccessOrExit(error = aRxInfo.mMessage.ReadLeaderDataTlv(leaderData));
 
-    SuccessOrExit(
-        error = Tlv::FindTlvValueOffset(aRxInfo.mMessage, Tlv::kNetworkData, networkDataOffset, networkDataLength));
+    VerifyOrExit(aRxInfo.mMessage.ContainsTlv(Tlv::kNetworkData));
 
     switch (Tlv::Find<ActiveTimestampTlv>(aRxInfo.mMessage, timestamp))
     {
@@ -3388,9 +3382,7 @@ void Mle::HandleChildIdResponse(RxInfo &aRxInfo)
 
     mParent.SetRloc16(sourceAddress);
 
-    IgnoreError(Get<NetworkData::Leader>().SetNetworkData(
-        leaderData.GetDataVersion(NetworkData::kFullSet), leaderData.GetDataVersion(NetworkData::kStableSubset),
-        GetNetworkDataType(), aRxInfo.mMessage, networkDataOffset, networkDataLength));
+    IgnoreError(aRxInfo.mMessage.ReadAndSetNetworkDataTlv(leaderData));
 
     SetStateChild(shortAddress);
 
@@ -5064,6 +5056,21 @@ exit:
     return error;
 }
 
+Error Mle::RxMessage::ReadAndSetNetworkDataTlv(const LeaderData &aLeaderData) const
+{
+    Error    error;
+    uint16_t offset;
+    uint16_t length;
+
+    SuccessOrExit(error = Tlv::FindTlvValueOffset(*this, Tlv::kNetworkData, offset, length));
+
+    error = Get<NetworkData::Leader>().SetNetworkData(aLeaderData.GetDataVersion(NetworkData::kFullSet),
+                                                      aLeaderData.GetDataVersion(NetworkData::kStableSubset),
+                                                      Get<Mle>().GetNetworkDataType(), *this, offset, length);
+exit:
+    return error;
+}
+
 Error Mle::RxMessage::ReadAndSaveActiveDataset(const MeshCoP::Timestamp &aActiveTimestamp) const
 {
     return ReadAndSaveDataset(MeshCoP::Dataset::kActive, aActiveTimestamp);
diff --git a/src/core/thread/mle.hpp b/src/core/thread/mle.hpp
index 318648b5e..a13c5f594 100644
--- a/src/core/thread/mle.hpp
+++ b/src/core/thread/mle.hpp
@@ -1072,6 +1072,7 @@ private:
         Error ReadFrameCounterTlvs(uint32_t &aLinkFrameCounter, uint32_t &aMleFrameCounter) const;
         Error ReadTlvRequestTlv(TlvList &aTlvList) const;
         Error ReadLeaderDataTlv(LeaderData &aLeaderData) const;
+        Error ReadAndSetNetworkDataTlv(const LeaderData &aLeaderData) const;
         Error ReadAndSaveActiveDataset(const MeshCoP::Timestamp &aActiveTimestamp) const;
         Error ReadAndSavePendingDataset(const MeshCoP::Timestamp &aPendingTimestamp) const;
 #if OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE