ncp-spinel: Update raw stream to support new metadata format (#717)

This commit updates the raw packet reporting mechanism to use
the [new Spinel metadata format][1] with `PROP_STREAM_RAW`.

To do this, a new boolean was needed for the `RadioPacket` structure
to allow us to differentiate packets that we received over the
air versus packets we have transmitted.

Since the format of the 802.15.4-PHY-specific metadata hasn't yet
been defined, that field (Along with the vendor data field) is left
unspecified.

[1]: https://cdn.rawgit.com/darconeous/openthread/5b887f3a4e7df5c0c806ca1ba80fb1d9619cf8f2/doc/draft-spinel-protocol.html#frame-metadata-format

include/platform/radio.h

@@ -96,13 +96,14 @@ typedef enum otRadioCaps
  */
 typedef struct RadioPacket
 {
-    uint8_t *mPsdu;          ///< The PSDU.
-    uint8_t mLength;         ///< Length of the PSDU.
-    uint8_t mChannel;        ///< Channel used to transmit/receive the frame.
-    int8_t  mPower;          ///< Transmit/receive power in dBm.
-    uint8_t mLqi;            ///< Link Quality Indicator for received frames.
-    bool    mSecurityValid;  ///< Security Enabled flag is set and frame passes security checks.
-    uint16_t mFcs;           ///< Final checksum (optional)
+    uint8_t  *mPsdu;           ///< The PSDU.
+    uint8_t  mLength;          ///< Length of the PSDU.
+    uint8_t  mChannel;         ///< Channel used to transmit/receive the frame.
+    int8_t   mPower;           ///< Transmit/receive power in dBm.
+    uint8_t  mLqi;             ///< Link Quality Indicator for received frames.
+    bool     mSecurityValid: 1; ///< Security Enabled flag is set and frame passes security checks.
+    bool     mDidTX: 1;        ///< Set to true if this packet sent from the radio. Ignored by radio driver.
+    uint16_t mFcs;             ///< Final checksum (optional)
 } RadioPacket;
 
 /**

src/core/mac/mac.cpp

@@ -657,6 +657,7 @@ void Mac::HandleBeginTransmit(void)
 
     if (mPcapCallback)
     {
+        sendFrame.mDidTX = true;
         mPcapCallback(&sendFrame, mPcapCallbackContext);
     }
 
@@ -1040,6 +1041,7 @@ void Mac::ReceiveDoneTask(Frame *aFrame, ThreadError aError)
 
     if (mPcapCallback)
     {
+        aFrame->mDidTX = false;
         mPcapCallback(aFrame, mPcapCallbackContext);
     }
 

src/ncp/ncp_base.cpp

@@ -523,6 +523,7 @@ void NcpBase::HandleRawFrame(const RadioPacket *aFrame, void *aContext)
 void NcpBase::HandleRawFrame(const RadioPacket *aFrame)
 {
     ThreadError errorCode = kThreadError_None;
+    uint16_t flags = 0;
 
     if (!mIsRawStreamEnabled)
     {
@@ -531,20 +532,32 @@ void NcpBase::HandleRawFrame(const RadioPacket *aFrame)
 
     SuccessOrExit(errorCode = OutboundFrameBegin());
 
-    // Append frame header and frame length
+    if (aFrame->mFcs != 0x0000)
+    {
+        flags |= SPINEL_MD_FLAG_HAS_FCS;
+    }
 
+    if (aFrame->mDidTX)
+    {
+        flags |= SPINEL_MD_FLAG_TX;
+    }
+
+    // Append frame header and frame length
     SuccessOrExit(
         errorCode = OutboundFrameFeedPacked(
             "CiiS",
             SPINEL_HEADER_FLAG | SPINEL_HEADER_IID_0,
             SPINEL_CMD_PROP_VALUE_IS,
             SPINEL_PROP_STREAM_RAW,
-            aFrame->mLength + 2 // +2 for FCS
+            aFrame->mLength + (
+                ((flags & SPINEL_MD_FLAG_HAS_FCS) == SPINEL_MD_FLAG_HAS_FCS)
+                ? 2 // +2 if we are appending the FCS
+                : 0 // +0 if we aren't appending the FCS
+            )
         )
     );
 
     // Append the frame contents
-
     SuccessOrExit(
         errorCode = OutboundFrameFeedData(
             aFrame->mPsdu,
@@ -552,21 +565,27 @@ void NcpBase::HandleRawFrame(const RadioPacket *aFrame)
         )
     );
 
-    // Append the FCS
-    SuccessOrExit(
-        errorCode = OutboundFrameFeedPacked(
-            "CC",
-            (aFrame->mFcs >> 0) & 0xFF,
-            (aFrame->mFcs >> 8) & 0xFF
-        )
-    );
+    if ((flags & SPINEL_MD_FLAG_HAS_FCS) == SPINEL_MD_FLAG_HAS_FCS)
+    {
+        // Append the FCS
+        SuccessOrExit(
+            errorCode = OutboundFrameFeedPacked(
+                "CC",
+                (aFrame->mFcs >> 0) & 0xFF,
+                (aFrame->mFcs >> 8) & 0xFF
+            )
+        );
+    }
 
     // Append metadata (rssi, etc)
-
     SuccessOrExit(
         errorCode = OutboundFrameFeedPacked(
-            "c",
-            aFrame->mPower
+            "ccS",
+            aFrame->mPower,   // TX Power
+            -128,             // Noise Floor (Currently unused)
+            flags             // Flags
+
+            // Skip PHY and Vendor data for now
         )
     );
 

src/ncp/spinel.h

@@ -244,6 +244,15 @@ typedef unsigned int spinel_size_t;
 typedef uint8_t spinel_tid_t;
 typedef unsigned int spinel_cid_t;
 
+enum
+{
+    SPINEL_MD_FLAG_TX               = 0x0001,
+    SPINEL_MD_FLAG_HAS_FCS          = 0x0002,
+    SPINEL_MD_FLAG_BAD_FCS          = 0x0004,
+    SPINEL_MD_FLAG_DUPE             = 0x0008,
+    SPINEL_MD_FLAG_RESERVED         = 0xFFF0,
+};
+
 enum
 {
     SPINEL_CMD_NOOP                 = 0,