From 30f20f3fbc51b96d666496977b4d67cc1eedbefd Mon Sep 17 00:00:00 2001
From: Jonathan Hui <jonhui@nestlabs.com>
Date: Fri, 8 Jun 2018 10:13:23 -0700
Subject: [PATCH] [mesh-forwarder] do not treat CCA failures the same as no-ack
 (#2765)

Thread 1.1.1 Section 5.9.4 states: "Note that failures to transmit due to
failed clear channel assessments do not count as a failure to receive an
ACK."
---
 src/core/thread/data_poll_manager.cpp  |  6 ++++++
 src/core/thread/mesh_forwarder.cpp     |  2 +-
 src/core/thread/mesh_forwarder_ftd.cpp | 20 +++++++++++++++-----
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/core/thread/data_poll_manager.cpp b/src/core/thread/data_poll_manager.cpp
index ec2437501..bcba9033c 100644
--- a/src/core/thread/data_poll_manager.cpp
+++ b/src/core/thread/data_poll_manager.cpp
@@ -217,6 +217,12 @@ void DataPollManager::HandlePollSent(otError aError)
 
         break;
 
+    case OT_ERROR_CHANNEL_ACCESS_FAILURE:
+    case OT_ERROR_ABORT:
+        mRetxMode                   = true;
+        shouldRecalculatePollPeriod = true;
+        break;
+
     default:
         mPollTxFailureCounter++;
 
diff --git a/src/core/thread/mesh_forwarder.cpp b/src/core/thread/mesh_forwarder.cpp
index 1342f8ea0..dee6b56b3 100644
--- a/src/core/thread/mesh_forwarder.cpp
+++ b/src/core/thread/mesh_forwarder.cpp
@@ -957,7 +957,7 @@ void MeshForwarder::HandleSentFrame(Mac::Frame &aFrame, otError aError)
 
     if (mSendMessage->GetDirectTransmission())
     {
-        if (aError != OT_ERROR_NONE)
+        if (aError == OT_ERROR_NO_ACK)
         {
             // If the transmission of any fragment frame fails,
             // the overall message transmission is considered
diff --git a/src/core/thread/mesh_forwarder_ftd.cpp b/src/core/thread/mesh_forwarder_ftd.cpp
index 8315434b5..257caf1f8 100644
--- a/src/core/thread/mesh_forwarder_ftd.cpp
+++ b/src/core/thread/mesh_forwarder_ftd.cpp
@@ -592,14 +592,18 @@ void MeshForwarder::HandleSentFrameToChild(const Mac::Frame &aFrame, otError aEr
         iter.Advance();
         mIndirectStartingChild = iter.GetChild();
 
-        if (aError == OT_ERROR_NONE)
+        switch (aError)
         {
+        case OT_ERROR_NONE:
             child->ResetIndirectTxAttempts();
-        }
-        else
-        {
-            child->IncrementIndirectTxAttempts();
+            break;
 
+        case OT_ERROR_NO_ACK:
+            child->IncrementIndirectTxAttempts();
+            // fall through
+
+        case OT_ERROR_CHANNEL_ACCESS_FAILURE:
+        case OT_ERROR_ABORT:
             if (child->GetIndirectTxAttempts() < kMaxPollTriggeredTxAttempts)
             {
                 // We save the frame counter, key id, and data sequence number of
@@ -634,6 +638,12 @@ void MeshForwarder::HandleSentFrameToChild(const Mac::Frame &aFrame, otError aEr
 
             mMessageNextOffset = mSendMessage->GetLength();
 #endif
+
+            break;
+
+        default:
+            assert(false);
+            break;
         }
     }