From ea28a1913bc6a1f8e04d7e504b824c6ba8fc8806 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Mon, 14 Mar 2022 10:52:54 -0700
Subject: [PATCH] [mle] add `RemoveDelayedMessage()` helper method (#7476)

This commit adds `Mle::RemoveDelayedMessage()` helper method which
removes messages with a given sub-type and an optional destination
IPv6 address from the `mDelayedResponses` message queue.
---
 src/core/thread/mle.cpp | 38 ++++++++++++++------------------------
 src/core/thread/mle.hpp |  3 ++-
 2 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index d8bbafc26..829facfdf 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -2020,41 +2020,31 @@ exit:
 
 void Mle::RemoveDelayedDataResponseMessage(void)
 {
-    Message *               message = mDelayedResponses.GetHead();
-    DelayedResponseMetadata metadata;
-
-    while (message != nullptr)
-    {
-        metadata.ReadFrom(*message);
-
-        if (message->GetSubType() == Message::kSubTypeMleDataResponse)
-        {
-            mDelayedResponses.DequeueAndFree(*message);
-            Log(kMessageRemoveDelayed, kTypeDataResponse, metadata.mDestination);
-
-            // no more than one multicast MLE Data Response in Delayed Message Queue.
-            break;
-        }
-
-        message = message->GetNext();
-    }
+    RemoveDelayedMessage(Message::kSubTypeMleDataResponse, kTypeDataResponse, nullptr);
 }
 
 void Mle::RemoveDelayedDataRequestMessage(const Ip6::Address &aDestination)
 {
-    for (Message *message = mDelayedResponses.GetHead(); message != nullptr; message = message->GetNext())
+    RemoveDelayedMessage(Message::kSubTypeMleDataRequest, kTypeDataRequest, &aDestination);
+}
+
+void Mle::RemoveDelayedMessage(Message::SubType aSubType, MessageType aMessageType, const Ip6::Address *aDestination)
+{
+    Message *nextMessage;
+
+    for (Message *message = mDelayedResponses.GetHead(); message != nullptr; message = nextMessage)
     {
         DelayedResponseMetadata metadata;
 
+        nextMessage = message->GetNext();
+
         metadata.ReadFrom(*message);
 
-        if (message->GetSubType() == Message::kSubTypeMleDataRequest && metadata.mDestination == aDestination)
+        if ((message->GetSubType() == aSubType) &&
+            ((aDestination == nullptr) || (metadata.mDestination == *aDestination)))
         {
             mDelayedResponses.DequeueAndFree(*message);
-            Log(kMessageRemoveDelayed, kTypeDataRequest, metadata.mDestination);
-
-            // no more than one MLE Data Request for the destination in Delayed Message Queue.
-            break;
+            Log(kMessageRemoveDelayed, aMessageType, metadata.mDestination);
         }
     }
 }
diff --git a/src/core/thread/mle.hpp b/src/core/thread/mle.hpp
index 39f1ec7bb..90617ba5b 100644
--- a/src/core/thread/mle.hpp
+++ b/src/core/thread/mle.hpp
@@ -1832,7 +1832,8 @@ private:
     bool     PrepareAnnounceState(void);
     void     SendAnnounce(uint8_t aChannel, AnnounceMode aMode);
     void     SendAnnounce(uint8_t aChannel, const Ip6::Address &aDestination, AnnounceMode aMode = kNormalAnnounce);
-    void     RemoveDelayedDataRequestMessage(const Ip6::Address &aDestination);
+    void RemoveDelayedMessage(Message::SubType aSubType, MessageType aMessageType, const Ip6::Address *aDestination);
+    void RemoveDelayedDataRequestMessage(const Ip6::Address &aDestination);
 #if OPENTHREAD_CONFIG_MLE_LINK_METRICS_SUBJECT_ENABLE
     Error SendLinkMetricsManagementResponse(const Ip6::Address &aDestination, LinkMetrics::Status aStatus);
 #endif