- IEC 61850 server/ MMS server: maximum number of client connections configurable at runtime

config/stack_config.h

@@ -51,7 +51,7 @@
 #define CONFIG_MMS_THREADLESS_STACK 0
 
 /* number of concurrent MMS client connections the server accepts, -1 for no limit */
-#define CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS 5
+#define CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS 100
 
 /* activate TCP keep alive mechanism. 1 -> activate */
 #define CONFIG_ACTIVATE_TCP_KEEPALIVE 1

dotnet/IEC61850forCSharp/IedServerConfig.cs

@@ -56,6 +56,19 @@ namespace IEC61850.Server
 		[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
 		static extern byte IedServerConfig_getEdition(IntPtr self);
 
+		[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+		static extern void IedServerConfig_setMaxMmsConnections(IntPtr self, int maxConnections);
+
+		[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+		static extern int IedServerConfig_getMaxMmsConnections(IntPtr self);
+
+		[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+		[return: MarshalAs(UnmanagedType.I1)]
+		static extern bool IedServerConfig_isDynamicDataSetServiceEnabled(IntPtr self);
+
+		[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+		static extern void IedServerConfig_enableDynamicDataSetService(IntPtr self, [MarshalAs(UnmanagedType.I1)] bool enable);
+
 		internal IntPtr self;
 
 		public IedServerConfig ()
@@ -91,6 +104,10 @@ namespace IEC61850.Server
 			}
 		}
 
+		/// <summary>
+		/// Gets or sets the edition of the IEC 61850 standard to use
+		/// </summary>
+		/// <value>The IEC 61850 edition to use.</value>
 		public Iec61850Edition Edition
 		{
 			get {
@@ -101,6 +118,30 @@ namespace IEC61850.Server
 			}
 		}
 
+		/// <summary>
+		/// Gets or sets maximum number of MMS clients
+		/// </summary>
+		/// <value>The max number of MMS client connections.</value>
+		public int MaxMmsConnections
+		{
+			get {
+				return IedServerConfig_getMaxMmsConnections (self);
+			}
+			set {
+				IedServerConfig_setMaxMmsConnections (self, value);
+			}
+		}
+
+		public bool DynamicDataSetServiceEnabled
+		{
+			get {
+				return IedServerConfig_isDynamicDataSetServiceEnabled (self);
+			}
+			set {
+				IedServerConfig_enableDynamicDataSetService (self, value);
+			}
+		}
+
 		/// <summary>
 		/// Releases all resource used by the <see cref="IEC61850.Server.IedServerConfig"/> object.
 		/// </summary>

examples/server_example_basic_io/server_example_basic_io.c

@@ -90,6 +90,7 @@ main(int argc, char** argv)
     /* Set buffer size for buffered report control blocks to 200000 bytes */
     IedServerConfig_setReportBufferSize(config, 200000);
 
+    /* Set stack compliance to a specific edition of the standard (WARNING: data model has also to be checked for compliance) */
     IedServerConfig_setEdition(config, IEC_61850_EDITION_2);
 
     /* Set the base path for the MMS file services */
@@ -103,6 +104,9 @@ main(int argc, char** argv)
 
     IedServerConfig_enableLogService(config, true);
 
+    /* set maximum number of clients */
+    IedServerConfig_setMaxMmsConnections(config, 2);
+
     /* Create a new IEC 61850 server instance */
     iedServer = IedServer_createWithConfig(&iedModel, NULL, config);
 
@@ -132,7 +136,7 @@ main(int argc, char** argv)
     IedServer_start(iedServer, 102);
 
     if (!IedServer_isRunning(iedServer)) {
-        printf("Starting server failed! Exit.\n");
+        printf("Starting server failed (maybe need root permissions or another server is already using the port)! Exit.\n");
         IedServer_destroy(iedServer);
         exit(-1);
     }

src/iec61850/inc/iec61850_server.h

@@ -65,6 +65,9 @@ struct sIedServerConfig
 
     /** IEC 61850 edition (0 = edition 1, 1 = edition 2, 2 = edition 2.1, ...) */
     uint8_t edition;
+
+    /** maximum number of MMS (TCP) connections */
+    int maxMmsConnections;
 };
 
 /**
@@ -113,9 +116,22 @@ IedServerConfig_setReportBufferSize(IedServerConfig self, int reportBufferSize);
 int
 IedServerConfig_getReportBufferSize(IedServerConfig self);
 
+/**
+ * \brief Set the maximum number of MMS (TCP) connections the server accepts
+ *
+ * NOTE: Parameter has to be smaller than CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS if
+ * CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS != -1
+ *
+ * \param maxConnection maximum number of TCP connections
+ */
 void
 IedServerConfig_setMaxMmsConnections(IedServerConfig self, int maxConnections);
 
+/**
+ * \brief Get the maximum number of MMS (TCP) connections the server accepts
+ *
+ * \return maximum number of TCP connections
+ */
 int
 IedServerConfig_getMaxMmsConnections(IedServerConfig self);
 
@@ -150,10 +166,10 @@ bool
 IedServerConfig_isFileServiceEnabled(IedServerConfig self);
 
 void
-IedServerConfig_enableFileWriteService(IedServerConfig self, bool enable);
+IedServerConfig_enableSetFileService(IedServerConfig self, bool enable);
 
 bool
-IedServerConfig_isFileWriteServiceEnabled(IedServerConfig self);
+IedServerConfig_isSetFileServiceEnabled(IedServerConfig self);
 
 /**
  * \brief Enable/disable the dynamic data set service for MMS

src/iec61850/server/impl/ied_server.c

@@ -439,6 +439,7 @@ IedServer_createWithConfig(IedModel* dataModel, TLSConfiguration tlsConfiguratio
             MmsServer_enableDynamicNamedVariableListService(self->mmsServer, serverConfiguration->enableDynamicDataSetService);
             MmsServer_enableJournalService(self->mmsServer, serverConfiguration->enableLogService);
             MmsServer_setFilestoreBasepath(self->mmsServer, serverConfiguration->fileServiceBasepath);
+            MmsServer_setMaxConnections(self->mmsServer, serverConfiguration->maxMmsConnections);
         }
 #endif
 

src/iec61850/server/impl/ied_server_config.c

@@ -125,3 +125,15 @@ IedServerConfig_isLogServiceEnabled(IedServerConfig self)
 {
     return self->enableLogService;
 }
+
+void
+IedServerConfig_setMaxMmsConnections(IedServerConfig self, int maxConnections)
+{
+    self->maxMmsConnections = maxConnections;
+}
+
+int
+IedServerConfig_getMaxMmsConnections(IedServerConfig self)
+{
+    return self->maxMmsConnections;
+}

src/mms/inc/iso_server.h

@@ -94,6 +94,9 @@ IsoServer_create(TLSConfiguration tlsConfiguration);
 void
 IsoServer_setTcpPort(IsoServer self, int port);
 
+void
+IsoServer_setMaxConnections(IsoServer self, int maxConnections);
+
 void
 IsoServer_setLocalIpAddress(IsoServer self, const char* ipAddress);
 

src/mms/inc/mms_server.h

@@ -225,6 +225,14 @@ MmsServer_installFileAccessHandler(MmsServer self, MmsFileAccessHandler handler,
 void
 MmsServer_setFilestoreBasepath(MmsServer self, const char* basepath);
 
+/**
+ * \brief Set the maximum number of TCP client connections
+ *
+ * \param[in] maxConnections the maximum number of TCP client connections to accept
+ */
+void
+MmsServer_setMaxConnections(MmsServer self, int maxConnections);
+
 /**
  * \brief Enable/disable MMS file services at runtime
  *

src/mms/inc_private/mms_server_internal.h

@@ -165,6 +165,7 @@ struct sMmsServer {
 #endif
 
 #if (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1)
+    int maxConnections;
     bool fileServiceEnabled;
     bool dynamicVariableListServiceEnabled;
     bool journalServiceEnabled;

src/mms/iso_mms/server/mms_server.c

@@ -107,6 +107,12 @@ MmsServer_setFilestoreBasepath(MmsServer self, const char* basepath)
 
 #if (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1)
 
+void
+MmsServer_setMaxConnections(MmsServer self, int maxConnections)
+{
+    IsoServer_setMaxConnections(self->isoServer, maxConnections);
+}
+
 void
 MmsServer_enableFileService(MmsServer self, bool enable)
 {

src/mms/iso_server/iso_server.c

@@ -72,10 +72,14 @@ struct sIsoServer {
 
     TLSConfiguration tlsConfiguration;
 
+#if (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1)
+    int maxConnections;
+#endif
+
 #if (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS == -1)
     LinkedList openClientConnections;
 #else
-    IsoConnection* openClientConnections;
+    IsoConnection openClientConnections[CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS];
 #endif /* (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS == -1) */
 
 #if (CONFIG_MMS_THREADLESS_STACK != 1)
@@ -355,11 +359,6 @@ setupIsoServer(IsoServer self)
 
     setState(self, ISO_SVR_STATE_RUNNING);
 
-#if (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS != -1)
-    if (DEBUG_ISO_SERVER)
-        printf("ISO_SERVER: server is limited to %i client connections.\n", (int) CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS);
-#endif
-
 exit_function:
     return success;
 }
@@ -374,6 +373,17 @@ handleIsoConnections(IsoServer self)
 
     if ((connectionSocket = ServerSocket_accept((ServerSocket) self->serverSocket)) != NULL) {
 
+#if (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1)
+        if (private_IsoServer_getConnectionCounter(self) >= self->maxConnections) {
+            if (DEBUG_ISO_SERVER)
+                printf("ISO_SERVER: maximum number of connections reached -> reject connection attempt.\n");
+
+            Socket_destroy(connectionSocket);
+
+            return;
+        }
+#endif /* (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1) */
+
 #if (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS != -1)
         if (private_IsoServer_getConnectionCounter(self) >= CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS) {
             if (DEBUG_ISO_SERVER)
@@ -416,6 +426,17 @@ handleIsoConnectionsThreadless(IsoServer self)
 
     if ((connectionSocket = ServerSocket_accept((ServerSocket) self->serverSocket)) != NULL) {
 
+#if (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1)
+        if (private_IsoServer_getConnectionCounter(self) >= self->maxConnections) {
+            if (DEBUG_ISO_SERVER)
+                printf("ISO_SERVER: maximum number of connections reached -> reject connection attempt.\n");
+
+            Socket_destroy(connectionSocket);
+
+            return;
+        }
+#endif /* (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1) */
+
 #if (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS != -1)
         if (private_IsoServer_getConnectionCounter(self) >= CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS) {
             if (DEBUG_ISO_SERVER)
@@ -499,9 +520,6 @@ IsoServer_create(TLSConfiguration tlsConfiguration)
 
 #if (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS == -1)
     self->openClientConnections = LinkedList_create();
-#else
-    self->openClientConnections = (IsoConnection*)
-            GLOBAL_CALLOC(CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS, sizeof(IsoConnection));
 #endif
 
 #if (CONFIG_MMS_THREADLESS_STACK != 1) && (CONFIG_MMS_SINGLE_THREADED == 0)
@@ -514,6 +532,14 @@ IsoServer_create(TLSConfiguration tlsConfiguration)
     return self;
 }
 
+#if (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1)
+void
+IsoServer_setMaxConnections(IsoServer self, int maxConnections)
+{
+    self->maxConnections = maxConnections;
+}
+#endif /* (CONFIG_MMS_SERVER_CONFIG_SERVICES_AT_RUNTIME == 1) */
+
 void
 IsoServer_setTcpPort(IsoServer self, int port)
 {
@@ -769,8 +795,6 @@ IsoServer_destroy(IsoServer self)
     lockClientConnections(self);
 #endif
 
-#else
-    GLOBAL_FREEMEM(self->openClientConnections);
 #endif /* (CONFIG_MAXIMUM_TCP_CLIENT_CONNECTIONS == -1) */
 
 #if (CONFIG_MMS_THREADLESS_STACK != 1) && (CONFIG_MMS_SINGLE_THREADED == 0)

src/vs/libiec61850-wo-goose.def

@@ -612,3 +612,5 @@ EXPORTS
     IedServerConfig_isLogServiceEnabled
     IedServerConfig_setEdition
     IedServerConfig_getEdition
+    IedServerConfig_setMaxMmsConnections
+    IedServerConfig_getMaxMmsConnections

src/vs/libiec61850.def

@@ -740,3 +740,5 @@ EXPORTS
     IedServerConfig_isLogServiceEnabled
     IedServerConfig_setEdition
     IedServerConfig_getEdition
+    IedServerConfig_setMaxMmsConnections
+    IedServerConfig_getMaxMmsConnections