- fixed - MMS server: messages can be corrupted when TCP buffer is full (LIB61850-385)

examples/mms_utility/mms_utility.c

@@ -101,6 +101,7 @@ printRawMmsMessage(void* parameter, uint8_t* message, int messageLength, bool re
 
 int main(int argc, char** argv)
 {
+    int returnCode = 0;
 
     char* hostname = StringUtils_copyString("localhost");
     int tcpPort = 102;
@@ -213,6 +214,10 @@ int main(int argc, char** argv)
 
     if (!MmsConnection_connect(con, &error, hostname, tcpPort)) {
         printf("MMS connect failed!\n");
+
+        if (error != MMS_ERROR_NONE)
+            returnCode = error;
+
         goto exit;
     }
     else
@@ -222,6 +227,9 @@ int main(int argc, char** argv)
         MmsServerIdentity* identity =
                 MmsConnection_identify(con, &error);
 
+        if (error != MMS_ERROR_NONE)
+            returnCode = error;
+
         if (identity != NULL) {
             printf("\nServer identity:\n----------------\n");
             printf("  vendor:\t%s\n", identity->vendorName);
@@ -235,14 +243,23 @@ int main(int argc, char** argv)
     if (readDeviceList) {
         printf("\nDomains present on server:\n--------------------------\n");
         LinkedList nameList = MmsConnection_getDomainNames(con, &error);
+
+        if (error != MMS_ERROR_NONE)
+            returnCode = error;
+
+        if (nameList) {
             LinkedList_printStringList(nameList);
             LinkedList_destroy(nameList);
         }
+    }
 
     if (getDeviceDirectory) {
         LinkedList variableList = MmsConnection_getDomainVariableNames(con, &error,
                 domainName);
 
+        if (error != MMS_ERROR_NONE)
+            returnCode = error;
+
         if (variableList) {
             LinkedList element = LinkedList_getNext(variableList);
 
@@ -264,6 +281,9 @@ int main(int argc, char** argv)
 
         variableList = MmsConnection_getDomainJournals(con, &error, domainName);
 
+        if (error != MMS_ERROR_NONE)
+            returnCode = error;
+
         if (variableList) {
 
             LinkedList element = variableList;
@@ -309,6 +329,9 @@ int main(int argc, char** argv)
             LinkedList journalEntries = MmsConnection_readJournalTimeRange(con, &error, logDomain, logName, startTime, endTime,
                     &moreFollows);
 
+            if (error != MMS_ERROR_NONE)
+                returnCode = error;
+
             MmsValue_delete(startTime);
             MmsValue_delete(endTime);
 
@@ -375,6 +398,8 @@ int main(int argc, char** argv)
 
             if (error != MMS_ERROR_NONE) {
                 printf("Reading variable failed: (ERROR %i)\n", error);
+
+                returnCode = error;
             }
             else {
                 printf("Read SUCCESS\n");
@@ -403,6 +428,8 @@ int main(int argc, char** argv)
 
             if (error != MMS_ERROR_NONE) {
                 printf("Reading variable failed: (ERROR %i)\n", error);
+
+                returnCode = error;
             }
             else {
                 printf("Read SUCCESS\n");
@@ -421,6 +448,8 @@ int main(int argc, char** argv)
 
             if (error != MMS_ERROR_NONE) {
                 printf("Reading variable list directory failed: (ERROR %i)\n", error);
+
+                returnCode = error;
             }
             else {
                 LinkedList varListElem = LinkedList_getNext(varListDir);
@@ -454,12 +483,19 @@ int main(int argc, char** argv)
         char* continueAfter = NULL;
 
         while (MmsConnection_getFileDirectory(con, &error, "", continueAfter, mmsFileDirectoryHandler, lastName)) {
+
+            if (error != MMS_ERROR_NONE)
+                returnCode = error;
+
             continueAfter = lastName;
         }
     }
 
     if (getFileAttributes) {
         MmsConnection_getFileDirectory(con, &error, filename, NULL, mmsGetFileAttributeHandler, NULL);
+
+        if (error != MMS_ERROR_NONE)
+            returnCode = error;
     }
 
     if (deleteFile) {
@@ -467,6 +503,7 @@ int main(int argc, char** argv)
 
         if (error != MMS_ERROR_NONE) {
             printf("Delete file failed: (ERROR %i)\n", error);
+            returnCode = error;
         }
         else {
             printf("File deleted\n");
@@ -482,6 +519,6 @@ int main(int argc, char** argv)
 
     MmsConnection_destroy(con);
 
-    return 0;
+    return returnCode;
 }
 

src/mms/inc_private/cotp.h

@@ -114,4 +114,7 @@ CotpConnection_getRemoteRef(CotpConnection* self);
 LIB61850_INTERNAL int
 CotpConnection_getLocalRef(CotpConnection* self);
 
+LIB61850_INTERNAL void
+CotpConnection_flushBuffer(CotpConnection* self);
+
 #endif /* COTP_H_ */

src/mms/iso_cotp/cotp.c

@@ -5,7 +5,7 @@
  *
  *  Partial implementation of the ISO 8073 COTP (ISO TP0) protocol for MMS.
  *
- *  Copyright 2013-2018 Michael Zillgith
+ *  Copyright 2013-2023 Michael Zillgith
  *
  *  This file is part of libIEC61850.
  *
@@ -174,6 +174,38 @@ writeToSocket(CotpConnection* self, uint8_t* buf, int size)
 #endif
 }
 
+static bool
+flushBuffer(CotpConnection* self)
+{
+    if (self->socketExtensionBufferFill > 0) {
+
+        int sentBytes = writeToSocket(self, self->socketExtensionBuffer, self->socketExtensionBufferFill);
+
+        if (sentBytes > 0) {
+
+            if (sentBytes != self->socketExtensionBufferFill) {
+                int target = 0;
+                int i;
+                uint8_t* buf = self->socketExtensionBuffer;
+
+                for (i = sentBytes; i < self->socketExtensionBufferFill; i++) {
+                    buf[target++] = buf[i];
+                }
+
+                self->socketExtensionBufferFill = self->socketExtensionBufferFill - sentBytes;
+            }
+            else {
+                self->socketExtensionBufferFill = 0;
+            }
+        }
+        else if (sentBytes == -1) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
 static bool
 sendBuffer(CotpConnection* self)
 {
@@ -182,7 +214,15 @@ sendBuffer(CotpConnection* self)
 
     bool retVal = false;
 
-    int sentBytes = writeToSocket(self, buffer, remainingSize);
+    if (flushBuffer(self) == false) {
+        goto exit_function;
+    }
+
+    int sentBytes = 0;
+
+    if (self->socketExtensionBufferFill == 0) {
+        sentBytes = writeToSocket(self, buffer, remainingSize);
+    }
 
     if (sentBytes == -1)
         goto exit_function;
@@ -215,33 +255,6 @@ exit_function:
     return retVal;
 }
 
-static void
-flushBuffer(CotpConnection* self)
-{
-    if (self->socketExtensionBufferFill > 0) {
-
-        int sentBytes = writeToSocket(self, self->socketExtensionBuffer, self->socketExtensionBufferFill);
-
-        if (sentBytes > 0) {
-
-            if (sentBytes != self->socketExtensionBufferFill) {
-                int target = 0;
-                int i;
-                uint8_t* buf = self->socketExtensionBuffer;
-
-                for (i = sentBytes; i < self->socketExtensionBufferFill; i++) {
-                    buf[target++] = buf[i];
-                }
-
-                self->socketExtensionBufferFill = self->socketExtensionBufferFill - sentBytes;
-            }
-            else {
-                self->socketExtensionBufferFill = 0;
-            }
-        }
-    }
-}
-
 CotpIndication
 CotpConnection_sendDataMessage(CotpConnection* self, BufferChain payload)
 {
@@ -262,7 +275,9 @@ CotpConnection_sendDataMessage(CotpConnection* self, BufferChain payload)
     int totalSize = (fragments * (COTP_DATA_HEADER_SIZE + 4)) + payload->length;
 
     /* try to flush extension buffer */
-    flushBuffer(self);
+    if (flushBuffer(self) == false) {
+        return COTP_ERROR;
+    }
 
     /* check if totalSize will fit in extension buffer */
     if (self->socketExtensionBuffer) {
@@ -281,7 +296,7 @@ CotpConnection_sendDataMessage(CotpConnection* self, BufferChain payload)
     int currentChainIndex = 0;
 
     if (DEBUG_COTP)
-        printf("\nCOTP: nextBufferPart: len:%i partLen:%i\n", currentChain->length, currentChain->partLength);
+        printf("COTP: nextBufferPart: len:%i partLen:%i\n", currentChain->length, currentChain->partLength);
 
     uint8_t* buffer = self->writeBuffer->buffer;
 
@@ -307,7 +322,7 @@ CotpConnection_sendDataMessage(CotpConnection* self, BufferChain payload)
             if (currentChainIndex >= currentChain->partLength) {
                 currentChain = currentChain->nextPart;
                 if (DEBUG_COTP)
-                    printf("\nCOTP: nextBufferPart: len:%i partLen:%i\n", currentChain->length, currentChain->partLength);
+                    printf("COTP: nextBufferPart: len:%i partLen:%i\n", currentChain->length, currentChain->partLength);
                 currentChainIndex = 0;
             }
 
@@ -756,6 +771,13 @@ readFromSocket(CotpConnection* self, uint8_t* buf, int size)
 #endif
 }
 
+void
+CotpConnection_flushBuffer(CotpConnection* self)
+{
+    if (self->socketExtensionBufferFill > 0)
+        flushBuffer(self);
+}
+
 TpktState
 CotpConnection_readToTpktBuffer(CotpConnection* self)
 {
@@ -765,6 +787,14 @@ CotpConnection_readToTpktBuffer(CotpConnection* self)
 
     assert (bufferSize > 4);
 
+    if (self->socketExtensionBufferFill > 0) {
+        if (flushBuffer(self) == false)
+            goto exit_error;
+
+        if (self->socketExtensionBufferFill > 0) 
+            goto exit_waiting;
+    }
+
     int readBytes;
 
     if (bufPos < 4) {

src/mms/iso_server/iso_connection.c

@@ -1,7 +1,7 @@
 /*
  *  iso_connection.c
  *
- *  Copyright 2013-2022 Michael Zillgith
+ *  Copyright 2013-2023 Michael Zillgith
  *
  *  This file is part of libIEC61850.
  *
@@ -160,6 +160,8 @@ IsoConnection_removeFromHandleSet(const IsoConnection self, HandleSet handles)
 void
 IsoConnection_callTickHandler(IsoConnection self)
 {
+    CotpConnection_flushBuffer(self->cotpConnection);
+
     if (self->tickHandler) {
         self->tickHandler(self->handlerParameter);
     }
@@ -171,10 +173,7 @@ IsoConnection_handleTcpConnection(IsoConnection self, bool isSingleThread)
 #if (CONFIG_MMS_SINGLE_THREADED != 1)
     if (isSingleThread == false) {
 
-        /* call tick handler */
-        if (self->tickHandler) {
-            self->tickHandler(self->handlerParameter);
-        }
+        IsoConnection_callTickHandler(self);
 
         if (Handleset_waitReady(self->handleSet, 10) < 1)
             goto exit_function;

src/mms/iso_server/iso_server.c

@@ -455,7 +455,6 @@ exit_function:
     return success;
 }
 
-
 /** used by single and multi-threaded versions
  *
  * \param isSingleThread when true server is running in single thread or non-thread mode