Log actual error that prevented a successful connection.

See merge request silecs/opensilecs!33

silecs-communication-cpp/src/silecs-communication/interface/communication/SilecsConnection.cpp

@@ -13,6 +13,7 @@ Contributors:
 
 #include <fcntl.h>
 #include <signal.h>
+#include <cstring>
 
 #include <silecs-communication/interface/equipment/SilecsCluster.h>
 #include <silecs-communication/interface/utility/SilecsLog.h>
@@ -107,15 +108,14 @@ bool Connection::doOpen(PLC* thePLC)
 
         if (!isTimeToReconnect())
         { // Do nothing, just wait a bit to dont pullute the log
-          return isConnected_;
+            return isConnected_;
         }
 
         if (ping(thePLC->getName().c_str(), NULL))
         {
-          logError(thePLC, false);
-          return isConnected_;
+            logError(thePLC, false);
+            return isConnected_;
         }
-
         // It's time to open the connection according to the (re)connection timing
         // Let's try several times with limited delay (some ms).
         // It allows wake-up frozen PLC (SIEMENS in particular) after long stop period.
@@ -298,7 +298,7 @@ void Connection::updateStatus(PLC* thePLC)
 void Connection::logError(PLC* thePLC, bool isReachable)
 {
     std::string errorMsg = isReachable ? "Connection with " + thePLC->getName() + ":" + thePLC->theCluster_->getClassName() + "/v" + thePLC->theCluster_->getClassVersion() + " has failed.\n" : "Controller " + thePLC->getName() + " does not respond to ping, might be OFF!\n";
-
+    errorMsg += "Error: " + std::string(std::strerror(errno)) + ". ";
     if (reconnectDelay_ == longDelay)
     {
         if (reconnectAttempts_ <  MAX_CONNECTION_ATTEMPTS_PER_DELAY)
@@ -455,6 +455,7 @@ int rfcPing(char *ip, long ts)
         /*if hostname is OFF, connect() fails on TIMEOUT*/
         if ( (errno == ETIMEDOUT) || (errno == EHOSTDOWN) || (errno == EHOSTUNREACH))
         {
+            LOG(ERROR) << "Error: " << strerror(errno);
             return -1;
         }
     }