[MCH] improved error detection in raw decoder

- badly formatted SYNC words
- SAMPA packet headers consistency
    - chip address and e-link index compatibility
    - num of 10-bit words multiple of 4 in cluster sum mode

Author: aferrero2707

Detectors/MUON/MCH/Raw/Decoder/include/MCHRawDecoder/ErrorCodes.h

@@ -25,16 +25,17 @@ enum ErrorCodes {
   ErrorParity = 1,                           // 1
   ErrorHammingCorrectable = 1 << 1,          // 2
   ErrorHammingUncorrectable = 1 << 2,        // 4
-  ErrorBadClusterSize = 1 << 3,              // 8
-  ErrorBadPacketType = 1 << 4,               // 16
-  ErrorBadHeartBeatPacket = 1 << 5,          // 32
-  ErrorBadIncompleteWord = 1 << 6,           // 64
-  ErrorTruncatedData = 1 << 7,               // 128
-  ErrorBadELinkID = 1 << 8,                  // 256
-  ErrorBadLinkID = 1 << 9,                   // 512
-  ErrorUnknownLinkID = 1 << 10,              // 1024
-  ErrorInvalidDigitTime = 1 << 11,           // 2048
-  ErrorNonRecoverableDecodingError = 1 << 12 // 4096
+  ErrorBadSyncPacket = 1 << 3,               // 8
+  ErrorBadHeartBeatPacket = 1 << 4,          // 16
+  ErrorBadDataPacket = 1 << 5,               // 32
+  ErrorBadClusterSize = 1 << 6,              // 64
+  ErrorBadIncompleteWord = 1 << 7,           // 128
+  ErrorTruncatedData = 1 << 8,               // 256
+  ErrorBadELinkID = 1 << 9,                  // 512
+  ErrorBadLinkID = 1 << 10,                  // 1024
+  ErrorUnknownLinkID = 1 << 11,              // 2048
+  ErrorBadHBTime = 1 << 12,                  // 4096
+  ErrorNonRecoverableDecodingError = 1 << 13 // 8192
 };
 
 uint32_t getErrorCodesSize();

Detectors/MUON/MCH/Raw/Decoder/src/ErrorCodes.cxx

@@ -20,7 +20,7 @@ namespace raw
 
 uint32_t getErrorCodesSize()
 {
-  return 13;
+  return 14;
 }
 
 void append(const char* msg, std::string& to)
@@ -49,12 +49,15 @@ std::string errorCodeAsString(uint32_t ec)
   if (ec & ErrorBadClusterSize) {
     append("Cluster Size", msg);
   }
-  if (ec & ErrorBadPacketType) {
-    append("Bad Packet Type", msg);
+  if (ec & ErrorBadSyncPacket) {
+    append("Bad Sync Packet", msg);
   }
   if (ec & ErrorBadHeartBeatPacket) {
     append("Bad HB Packet", msg);
   }
+  if (ec & ErrorBadDataPacket) {
+    append("Bad Data Packet", msg);
+  }
   if (ec & ErrorBadIncompleteWord) {
     append("Bad Incomplete Word", msg);
   }
@@ -70,8 +73,8 @@ std::string errorCodeAsString(uint32_t ec)
   if (ec & ErrorUnknownLinkID) {
     append("Unknown Link ID", msg);
   }
-  if (ec & ErrorInvalidDigitTime) {
-    append("Invalid Digit Time", msg);
+  if (ec & ErrorBadHBTime) {
+    append("Bad HB Time", msg);
   }
   if (ec & ErrorNonRecoverableDecodingError) {
     append("Non Recoverable", msg);

Detectors/MUON/MCH/Raw/Decoder/src/UserLogicElinkDecoder.cxx

@@ -38,4 +38,42 @@ void UserLogicElinkDecoder<ChargeSumMode>::prepareAndSendCluster()
   mSamples.clear();
 }
 
+template <>
+bool UserLogicElinkDecoder<SampleMode>::checkDataHeader()
+{
+  int chipAddMin = mDsId.elinkIndexInGroup() * 2;
+  int chipAddMax = chipAddMin + 1;
+
+  // the chip address from the SAMPA header must be consistent with
+  // the e-Link index
+  int chipAdd = mSampaHeader.chipAddress();
+  if (chipAdd < chipAddMin || chipAdd > chipAddMax) {
+    return false;
+  }
+
+  return true;
+}
+
+template <>
+bool UserLogicElinkDecoder<ChargeSumMode>::checkDataHeader()
+{
+  int chipAddMin = mDsId.elinkIndexInGroup() * 2;
+  int chipAddMax = chipAddMin + 1;
+
+  // the chip address from the SAMPA header must be consistent with
+  // the e-Link index
+  int chipAdd = mSampaHeader.chipAddress();
+  if (chipAdd < chipAddMin || chipAdd > chipAddMax) {
+    return false;
+  }
+
+  // in cluster sum mode the number of 10-bit words must be a multiple of 4
+  int nof10BitWords = mSampaHeader.nof10BitWords();
+  if ((nof10BitWords % 4) != 0) {
+    return false;
+  }
+
+  return true;
+}
+
 } // namespace o2::mch::raw

Detectors/MUON/MCH/Raw/Decoder/src/UserLogicElinkDecoder.h

@@ -73,6 +73,7 @@ class UserLogicElinkDecoder
   void completeHeader();
   void oneLess10BitWord();
   void prepareAndSendCluster();
+  bool checkDataHeader();
   void sendCluster(const SampaCluster& sc) const;
   void sendHBPacket();
   void sendError(int8_t chip, uint32_t error) const;
@@ -185,7 +186,11 @@ bool UserLogicElinkDecoder<CHARGESUM>::append10(uint10_t data10)
       setHeaderPart(data10);
       if (isHeaderComplete()) {
         completeHeader();
-        if (isSync(mSampaHeader.uint64())) {
+        if (mSampaHeader.packetType() == SampaPacketType::Sync) {
+          if (!isSync(mSampaHeader.uint64())) {
+            mErrorMessage = "badly formatted Sync packet";
+            sendError(static_cast<int8_t>(mSampaHeader.chipAddress()), static_cast<uint32_t>(ErrorBadSyncPacket));
+          }
           reset();
         } else if (mSampaHeader.packetType() == SampaPacketType::HeartBeat) {
           if (mSampaHeader.isHeartbeat()) {
@@ -198,9 +203,15 @@ bool UserLogicElinkDecoder<CHARGESUM>::append10(uint10_t data10)
             reset();
           }
         } else {
-          if (mSampaHeader.nof10BitWords() > 2) {
-            transition(State::WaitingSize);
+          if (checkDataHeader()) {
+            if (mSampaHeader.nof10BitWords() > 2) {
+              transition(State::WaitingSize);
+            } else {
+              reset();
+            }
           } else {
+            mErrorMessage = "badly formatted Data packet";
+            sendError(static_cast<int8_t>(mSampaHeader.chipAddress()), static_cast<uint32_t>(ErrorBadDataPacket));
             reset();
           }
         }