From 5d6dccf35c038e7da43167c6789c79a728a3e3c7 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Tue, 27 Nov 2018 10:05:18 -0800
Subject: [PATCH] [radio-spinel] determine presence of Ack from spinel TxDone
 frame (#3313)

This commit changes `RadioSpinel` to determine if Ack is present
directly from the received spinel TxDone frame (i.e. check the
remaining unparsed length of spinel frame to determine if ack frame is
included by Radio Co-Processor (RCP)). This change helps simplify the
code by removing the requirement for `RadioSpinel` as the layer
between OpenThread core and RCP to parse the 15.4 frame.
---
 src/posix/platform/radio_spinel.cpp | 63 +++++------------------------
 src/posix/platform/radio_spinel.hpp |  1 -
 2 files changed, 9 insertions(+), 55 deletions(-)

diff --git a/src/posix/platform/radio_spinel.cpp b/src/posix/platform/radio_spinel.cpp
index 8cd57df8a..33f93f53a 100644
--- a/src/posix/platform/radio_spinel.cpp
+++ b/src/posix/platform/radio_spinel.cpp
@@ -54,55 +54,8 @@
 #include <openthread/platform/diag.h>
 #include <openthread/platform/radio.h>
 
-enum
-{
-    IEEE802154_MIN_LENGTH = 5,
-    IEEE802154_MAX_LENGTH = 127,
-    IEEE802154_ACK_LENGTH = 5,
-
-    IEEE802154_BROADCAST = 0xffff,
-
-    IEEE802154_FRAME_TYPE_ACK    = 2 << 0,
-    IEEE802154_FRAME_TYPE_MACCMD = 3 << 0,
-    IEEE802154_FRAME_TYPE_MASK   = 7 << 0,
-
-    IEEE802154_SECURITY_ENABLED  = 1 << 3,
-    IEEE802154_FRAME_PENDING     = 1 << 4,
-    IEEE802154_ACK_REQUEST       = 1 << 5,
-    IEEE802154_PANID_COMPRESSION = 1 << 6,
-
-    IEEE802154_DST_ADDR_NONE  = 0 << 2,
-    IEEE802154_DST_ADDR_SHORT = 2 << 2,
-    IEEE802154_DST_ADDR_EXT   = 3 << 2,
-    IEEE802154_DST_ADDR_MASK  = 3 << 2,
-
-    IEEE802154_SRC_ADDR_NONE  = 0 << 6,
-    IEEE802154_SRC_ADDR_SHORT = 2 << 6,
-    IEEE802154_SRC_ADDR_EXT   = 3 << 6,
-    IEEE802154_SRC_ADDR_MASK  = 3 << 6,
-
-    IEEE802154_DSN_OFFSET     = 2,
-    IEEE802154_DSTPAN_OFFSET  = 3,
-    IEEE802154_DSTADDR_OFFSET = 5,
-
-    IEEE802154_SEC_LEVEL_MASK = 7 << 0,
-
-    IEEE802154_KEY_ID_MODE_0    = 0 << 3,
-    IEEE802154_KEY_ID_MODE_1    = 1 << 3,
-    IEEE802154_KEY_ID_MODE_2    = 2 << 3,
-    IEEE802154_KEY_ID_MODE_3    = 3 << 3,
-    IEEE802154_KEY_ID_MODE_MASK = 3 << 3,
-
-    IEEE802154_MACCMD_DATA_REQ = 4,
-};
-
 static ot::PosixApp::RadioSpinel sRadioSpinel;
 
-static inline bool isAckRequested(const uint8_t *frame)
-{
-    return (frame[0] & IEEE802154_ACK_REQUEST) != 0;
-}
-
 namespace ot {
 namespace PosixApp {
 
@@ -206,7 +159,6 @@ RadioSpinel::RadioSpinel(void)
     , mWaitingKey(SPINEL_PROP_LAST_STATUS)
     , mRxSensitivity(0)
     , mState(kStateDisabled)
-    , mIsAckRequested(false)
     , mIsPromiscuous(false)
     , mIsReady(false)
     , mSupportsLogStream(false)
@@ -725,7 +677,8 @@ void RadioSpinel::Process(const fd_set &aReadFdSet, const fd_set &aWriteFdSet)
         else
 #endif
         {
-            otPlatRadioTxDone(mInstance, mTransmitFrame, (mIsAckRequested ? &mAckRadioFrame : NULL), mTxError);
+            otPlatRadioTxDone(mInstance, mTransmitFrame, (mAckRadioFrame.mLength != 0) ? &mAckRadioFrame : NULL,
+                              mTxError);
         }
     }
 
@@ -1043,8 +996,6 @@ void RadioSpinel::RadioTransmit(void)
     otPlatRadioTxStarted(mInstance, mTransmitFrame);
     assert(mState == kStateTransmitPending);
 
-    mIsAckRequested = isAckRequested(mTransmitFrame->mPsdu) && !mIsPromiscuous;
-
     error = Request(true, SPINEL_CMD_PROP_VALUE_SET, SPINEL_PROP_STREAM_RAW,
                     SPINEL_DATATYPE_DATA_WLEN_S SPINEL_DATATYPE_UINT8_S SPINEL_DATATYPE_INT8_S, mTransmitFrame->mPsdu,
                     mTransmitFrame->mLength, mTransmitFrame->mChannel, mTransmitFrame->mInfo.mRxInfo.mRssi);
@@ -1189,11 +1140,14 @@ void RadioSpinel::HandleTransmitDone(uint32_t          aCommand,
         aBuffer += unpacked;
         aLength -= static_cast<spinel_size_t>(unpacked);
 
-        if (mIsAckRequested)
+        if (aLength > 0)
         {
-            VerifyOrExit(aLength > 0, error = OT_ERROR_FAILED);
             SuccessOrExit(error = ParseRadioFrame(mAckRadioFrame, aBuffer, aLength));
         }
+        else
+        {
+            mAckRadioFrame.mLength = 0;
+        }
     }
     else
     {
@@ -1567,7 +1521,8 @@ void ot::PosixApp::RadioSpinel::Process(const Event &aEvent)
         else
 #endif
         {
-            otPlatRadioTxDone(mInstance, mTransmitFrame, (mIsAckRequested ? &mAckRadioFrame : NULL), mTxError);
+            otPlatRadioTxDone(mInstance, mTransmitFrame, (mAckRadioFrame.mLength != 0) ? &mAckRadioFrame : NULL,
+                              mTxError);
         }
     }
 
diff --git a/src/posix/platform/radio_spinel.hpp b/src/posix/platform/radio_spinel.hpp
index c7f7321ff..ce872ad5c 100644
--- a/src/posix/platform/radio_spinel.hpp
+++ b/src/posix/platform/radio_spinel.hpp
@@ -609,7 +609,6 @@ private:
     char         mVersion[kVersionStringSize];
 
     State mState;
-    bool  mIsAckRequested : 1;    ///< Ack requested.
     bool  mIsPromiscuous : 1;     ///< Promiscuous mode.
     bool  mIsReady : 1;           ///< NCP ready.
     bool  mSupportsLogStream : 1; ///< RCP supports `LOG_STREAM` property with OpenThread log meta-data format.