From dfeb9fd5a57ec6af75a081b39fa53a22a6aa21fd Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@gmail.com>
Date: Wed, 6 Mar 2019 09:30:14 -0800
Subject: [PATCH] more Troubleshoot "no more data in UDP packet"

---
 src/remote/abstractResponseHandler.cpp |  2 +-
 src/remote/blockingUDPTransport.cpp    | 20 +++++++++++++-------
 src/remoteClient/clientContextImpl.cpp | 10 +++-------
 src/server/responseHandlers.cpp        |  7 +++----
 4 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/src/remote/abstractResponseHandler.cpp b/src/remote/abstractResponseHandler.cpp
index 1a494f0..f2d5f2d 100644
--- a/src/remote/abstractResponseHandler.cpp
+++ b/src/remote/abstractResponseHandler.cpp
@@ -42,7 +42,7 @@ void ResponseHandler::handleResponse(osiSockAddr* responseFrom,
         std::cerr<<"Message [0x"<<std::hex<<(int)command<<", v0x"<<std::hex
                  <<int(version)<<"] received from "<<ipAddrStr<<" on "<<transport->getRemoteName()
                  <<" : "<<_description<<"\n"
-                 <<HexDump(*payloadBuffer, payloadSize);
+                 <<HexDump(*payloadBuffer, payloadSize).limit(0xffff);
     }
 }
 }
diff --git a/src/remote/blockingUDPTransport.cpp b/src/remote/blockingUDPTransport.cpp
index cc4d070..db0e366 100644
--- a/src/remote/blockingUDPTransport.cpp
+++ b/src/remote/blockingUDPTransport.cpp
@@ -27,6 +27,7 @@
 #include <pv/inetAddressUtil.h>
 #include <pv/logger.h>
 #include <pv/likely.h>
+#include <pv/hexDump.h>
 
 using namespace epics::pvData;
 using namespace std;
@@ -267,13 +268,18 @@ void BlockingUDPTransport::run() {
                     try {
                         processBuffer(thisTransport, fromAddress, &_receiveBuffer);
                     } catch(std::exception& e) {
-                        LOG(logLevelError,
-                            "an exception caught while in UDP receiveThread %s at %s:%d: %s",
-                            _remoteName.c_str(), __FILE__, __LINE__, e.what());
-                    } catch (...) {
-                        LOG(logLevelError,
-                            "unknown exception caught while in UDP receiveThread %s at %s:%d.",
-                            _remoteName.c_str(), __FILE__, __LINE__);
+                        if(IS_LOGGABLE(logLevelError)) {
+                            char strBuffer[64];
+                            sockAddrToDottedIP(&fromAddress.sa, strBuffer, sizeof(strBuffer));
+                            size_t epos = _receiveBuffer.getPosition();
+
+                            // of course _receiveBuffer _may_ have been modified during processing...
+                            _receiveBuffer.setPosition(RECEIVE_BUFFER_PRE_RESERVE);
+                            _receiveBuffer.setLimit(RECEIVE_BUFFER_PRE_RESERVE+bytesRead);
+
+                            std::cerr<<"Error on UDP RX "<<strBuffer<<" -> "<<_remoteName<<" at "<<epos<<" : "<<e.what()<<"\n"
+                                      <<HexDump(_receiveBuffer).limit(256u);
+                        }
                     }
                 }
             } else {
diff --git a/src/remoteClient/clientContextImpl.cpp b/src/remoteClient/clientContextImpl.cpp
index 68f507d..13d2236 100644
--- a/src/remoteClient/clientContextImpl.cpp
+++ b/src/remoteClient/clientContextImpl.cpp
@@ -2998,13 +2998,9 @@ public:
     {
         if (command < 0 || command >= (int8)m_handlerTable.size())
         {
-            LOG(logLevelError,
-                "Invalid (or unsupported) command: %x.", (0xFF&command));
-
-            if(pvAccessIsLoggable(logLevelError)) {
-                std::cerr<<"Invalid PVA header "<<hex<<(int)(0xFF&command)
-                         <<", its payload buffer\n"
-                         <<HexDump(*payloadBuffer, payloadSize);
+            if(IS_LOGGABLE(logLevelError)) {
+                std::cerr<<"Invalid (or unsupported) command: "<<std::hex<<(int)(0xFF&command)<<"\n"
+                         <<HexDump(*payloadBuffer, payloadSize).limit(256u);
             }
             return;
         }
diff --git a/src/server/responseHandlers.cpp b/src/server/responseHandlers.cpp
index b04a5d2..f0dd766 100644
--- a/src/server/responseHandlers.cpp
+++ b/src/server/responseHandlers.cpp
@@ -158,10 +158,9 @@ void ServerResponseHandler::handleResponse(osiSockAddr* responseFrom,
         LOG(logLevelError,
             "Invalid (or unsupported) command: %x.", (0xFF&command));
 
-        if(pvAccessIsLoggable(logLevelError)) {
-            std::cerr<<"Invalid PVA header "<<hex<<(int)(0xFF&command)
-                     <<", its payload buffer\n"
-                     <<HexDump(*payloadBuffer, payloadSize);
+        if(IS_LOGGABLE(logLevelError)) {
+            std::cerr<<"Invalid (or unsupported) command: "<<std::hex<<(int)(0xFF&command)<<"\n"
+                     <<HexDump(*payloadBuffer, payloadSize).limit(256u);
         }
         return;
     }