fix #644; sending tcp messages in blocks

plugins/networklayer_tcp.c

@@ -72,8 +72,13 @@ socket_write(UA_Connection *connection, UA_ByteString *buf) {
     do {
         ssize_t n = 0;
         do {
+        /*
+         * If the OS throws EMSGSIZE, force a smaller packet size:
+         *  size_t bytes_to_send = buf->length - nWritten >  1024 ? 1024 : buf->length - nWritten;
+         */
+            size_t bytes_to_send = buf->length - nWritten;
 #ifdef _WIN32
-            n = send((SOCKET)connection->sockfd, (const char*)buf->data, buf->length, 0);
+            n = send((SOCKET)connection->sockfd, (const char*)buf->data + nWritten, bytes_to_send, 0);
             const int last_error = WSAGetLastError();
             if(n < 0 && last_error != WSAEINTR && last_error != WSAEWOULDBLOCK) {
                 connection->close(connection);
@@ -82,7 +87,7 @@ socket_write(UA_Connection *connection, UA_ByteString *buf) {
                 return UA_STATUSCODE_BADCONNECTIONCLOSED;
             }
 #else
-            n = send(connection->sockfd, (const char*)buf->data, buf->length, MSG_NOSIGNAL);
+            n = send(connection->sockfd, (const char*)buf->data + nWritten, bytes_to_send, MSG_NOSIGNAL);
             if(n == -1L && errno != EINTR && errno != EAGAIN) {
                 connection->close(connection);
                 socket_close(connection);
@@ -111,9 +116,9 @@ socket_recv(UA_Connection *connection, UA_ByteString *response, UA_UInt32 timeou
         UA_UInt32 timeout_usec = timeout * 1000;
     #ifdef __APPLE__
         struct timeval tmptv = {(long int)(timeout_usec / 1000000), timeout_usec % 1000000};
-	#else
+    #else
         struct timeval tmptv = {(long int)(timeout_usec / 1000000), (long int)(timeout_usec % 1000000)};
-	#endif
+    #endif
         int ret = setsockopt(connection->sockfd, SOL_SOCKET, SO_RCVTIMEO, (const char *)&tmptv, sizeof(struct timeval));
 #else
         DWORD timeout_dw = timeout;
@@ -135,9 +140,9 @@ socket_recv(UA_Connection *connection, UA_ByteString *response, UA_UInt32 timeou
         UA_UInt32 timeout_usec = timeout * 1000;
     #ifdef __APPLE__
         struct timeval tmptv = {(long int)(timeout_usec / 1000000), timeout_usec % 1000000};
-	#else
+    #else
         struct timeval tmptv = {(long int)(timeout_usec / 1000000), (long int)(timeout_usec % 1000000)};
-	#endif
+    #endif
         UA_Int32 retval;
 
         FD_ZERO(&fdset);
@@ -289,7 +294,7 @@ ServerNetworkLayerTCP_closeConnection(UA_Connection *connection) {
         return;
     connection->state = UA_CONNECTION_CLOSED;
 #endif
-#if UA_LOGLEVEL <= 300   
+#if UA_LOGLEVEL <= 300
    //cppcheck-suppress unreadVariable
     ServerNetworkLayerTCP *layer = connection->handle;
     UA_LOG_INFO(layer->logger, UA_LOGCATEGORY_NETWORK, "Connection %i | Force closing the connection",