From 034a97eed2e6f6521e3d82d667eba57d400e68b6 Mon Sep 17 00:00:00 2001
From: Timofei Istomin <tim.ist@gmail.com>
Date: Thu, 28 May 2015 21:51:02 +0200
Subject: [PATCH] Don't generate a zero-length packet in case of errors.

The packet converter used to generate packets of length zero
when it encountered errors during conversion. This caused
exceptions in packet analyzers.

Now the converter returns null in case of error. Appropriate
checks have been added to the code that uses the return value.
---
 .../interfaces/CC2420RadioPacketConverter.java        |  2 +-
 .../cooja/mspmote/interfaces/Msp802154Radio.java      | 11 +++++++----
 .../cooja/motes/AbstractApplicationMote.java          |  3 ++-
 .../java/org/contikios/cooja/plugins/RadioLogger.java |  4 +++-
 4 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java b/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java
index 3fda7681d..946e2398c 100644
--- a/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java
+++ b/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/CC2420RadioPacketConverter.java
@@ -198,7 +198,7 @@ public class CC2420RadioPacketConverter {
     System.arraycopy(data, 6 /* skipping preamble+synch+len */, originalData, 0, originalLen);
     if (len < 0) {
       /*logger.warn("No cross-level conversion available: negative packet length");*/
-      return new ConvertedRadioPacket(new byte[0], originalData);
+      return null;
     }
     byte convertedData[] = new byte[len];
     System.arraycopy(data, pos, convertedData, 0, len);
diff --git a/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/Msp802154Radio.java b/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/Msp802154Radio.java
index c99710f3d..9937e6a74 100644
--- a/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/Msp802154Radio.java
+++ b/tools/cooja/apps/mspsim/src/org/contikios/cooja/mspmote/interfaces/Msp802154Radio.java
@@ -99,6 +99,7 @@ public class Msp802154Radio extends Radio implements CustomDataRadio {
       public void receivedByte(byte data) {
         if (!isTransmitting()) {
           lastEvent = RadioEvent.TRANSMISSION_STARTED;
+          lastOutgoingPacket = null;
           isTransmitting = true;
           len = 0;
           expMpduLen = 0;
@@ -139,10 +140,12 @@ public class Msp802154Radio extends Radio implements CustomDataRadio {
 
         if (((expMpduLen & 0x80) == 0) && len == expMpduLen + 6 && isSynchronized) {
           lastOutgoingPacket = CC2420RadioPacketConverter.fromCC2420ToCooja(buffer);
-          lastEvent = RadioEvent.PACKET_TRANSMITTED;
-          //logger.debug("----- 802.15.4 PACKET TRANSMITTED -----");
-          setChanged();
-          notifyObservers();
+          if (lastOutgoingPacket != null) {
+            lastEvent = RadioEvent.PACKET_TRANSMITTED;
+            //logger.debug("----- 802.15.4 PACKET TRANSMITTED -----");
+            setChanged();
+            notifyObservers();
+          }
           isSynchronized = false;
         }
       }
diff --git a/tools/cooja/java/org/contikios/cooja/motes/AbstractApplicationMote.java b/tools/cooja/java/org/contikios/cooja/motes/AbstractApplicationMote.java
index 98de78327..fd16d37a3 100644
--- a/tools/cooja/java/org/contikios/cooja/motes/AbstractApplicationMote.java
+++ b/tools/cooja/java/org/contikios/cooja/motes/AbstractApplicationMote.java
@@ -76,7 +76,8 @@ public abstract class AbstractApplicationMote extends AbstractWakeupMote impleme
         if (radio.getLastPacketReceived() != null)
             receivedPacket(radio.getLastPacketReceived());
       } else if (radio.getLastEvent() == Radio.RadioEvent.TRANSMISSION_FINISHED) {
-        sentPacket(radio.getLastPacketTransmitted());
+        if (radio.getLastPacketTransmitted() != null)
+            sentPacket(radio.getLastPacketTransmitted());
       }
     }
   };
diff --git a/tools/cooja/java/org/contikios/cooja/plugins/RadioLogger.java b/tools/cooja/java/org/contikios/cooja/plugins/RadioLogger.java
index 17f5417c2..abdc76f6c 100644
--- a/tools/cooja/java/org/contikios/cooja/plugins/RadioLogger.java
+++ b/tools/cooja/java/org/contikios/cooja/plugins/RadioLogger.java
@@ -517,10 +517,12 @@ public class RadioLogger extends VisPlugin {
           return;
         }
         final RadioConnectionLog loggedConn = new RadioConnectionLog();
+        loggedConn.packet = conn.getSource().getLastPacketTransmitted();
+        if (loggedConn.packet == null)
+          return;
         loggedConn.startTime = conn.getStartTime();
         loggedConn.endTime = simulation.getSimulationTime();
         loggedConn.connection = conn;
-        loggedConn.packet = conn.getSource().getLastPacketTransmitted();
         java.awt.EventQueue.invokeLater(new Runnable() {
           @Override
           public void run() {