Add support for Multi UE MEC applications

src/apps/mec/DeviceApp/DeviceApp.cc

@@ -68,7 +68,14 @@ void DeviceApp::handleUALCMPMessage()
                         nlohmann::json appInfo = jsonResponseBody["appList"];
                         if(appName.compare(appInfo.at(i)["appName"]) == 0)
                         {
-                            jsonRequestBody["associateDevAppId"] = std::to_string(getId());
+                            // search fo the app name in the list of shared apps. if found, use the stored dev app id
+                            auto sharedDevAppId = devAppIds.find(std::string(appName));
+                            int associateDevAppId;
+                            if (sharedDevAppId != devAppIds.end())
+                                associateDevAppId = sharedDevAppId->second;
+                            else
+                                associateDevAppId = getId();
+                            jsonRequestBody["associateDevAppId"] = std::to_string(associateDevAppId);
                             jsonRequestBody["appInfo"]["appDId"] = appInfo.at(i)["appDId"];// "WAMECAPP_External"; //startPk->getMecAppDId()
                             //    jsonBody["appInfo"]["appPackageSource"] = "ApplicationDescriptors/WarningAlertApp.json";
 
@@ -82,7 +89,14 @@ void DeviceApp::handleUALCMPMessage()
                     if(found == false)
                     {
                         EV << "DeviceApp::handleUALCMPMessage: application descriptor for appName: " << appName << " not found." << endl;
-                        jsonRequestBody["associateDevAppId"] = std::to_string(getId());
+                        // search fo the app name in the list of shared apps. if found, use the stored dev app id
+                        auto sharedDevAppId = devAppIds.find(std::string(appName));
+                        int associateDevAppId;
+                        if (sharedDevAppId != devAppIds.end())
+                            associateDevAppId = sharedDevAppId->second;
+                        else
+                            associateDevAppId = getId();
+                        jsonRequestBody["associateDevAppId"] = std::to_string(associateDevAppId);
                         jsonRequestBody["appInfo"]["appPackageSource"] = appPackageSource; //"ApplicationDescriptors/WarningAlertApp.json";
 
                         jsonRequestBody["appInfo"]["appName"] = appName;//"MEWarningAlertApp_rest";
@@ -383,6 +397,10 @@ void DeviceApp::sendStartAppContext(inet::Ptr<const DeviceAppPacket> pk)
      * ask the proxy for the requested app, by appName
      */
     appName = startPk->getMecAppName();
+    if (startPk->getShared()) {
+        // if this is a shared app, store the dev app id to be associated when sending the start request
+        devAppIds[std::string(appName)] = startPk->getAssociateDevAppId();
+    }
 
     std::string uri("/example/dev_app/v1/app_list");
     std::stringstream params;

src/apps/mec/DeviceApp/DeviceApp.h

@@ -73,6 +73,8 @@ class DeviceApp : public omnetpp::cSimpleModule, public inet::TcpSocket::ICallba
 
         State appState;
         std::string appName;
+        // mapping from app names to app dev id to use (only used for shared apps)
+        std::map<std::string, int> devAppIds;
 
         // variable set in ned, if the appDescriptor is not in the MEC orchestrator
 //        std::string appProvider; not used

src/apps/mec/DeviceApp/DeviceAppMessages/DeviceAppPacket.msg

@@ -36,6 +36,10 @@ class DeviceAppStartPacket extends DeviceAppPacket
 	string mecAppName;
 	string mecAppProvider;
 	string appPackageSource;
+    // determines whether the instantiated app should be unique for every UE or shared among them
+    bool shared = false;
+    // if the MEC app is shared, determines which DevAppId should be used
+    int associateDevAppId = -1;
 }
 
 class DeviceAppStopPacket extends DeviceAppPacket

src/apps/mec/MecApps/MultiUEMECApp.cc

@@ -0,0 +1,27 @@
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+// 
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see http://www.gnu.org/licenses/.
+// 
+
+#include "MultiUEMECApp.h"
+
+namespace simu5g {
+
+Define_Module(MultiUEMECApp);
+
+void MultiUEMECApp::addNewUE(struct UE_MEC_CLIENT ueData)
+{
+    throw cRuntimeError("Every MEC app inheriting from MultiUEMECApp must override and implement the addNewUE method");
+}
+
+}

src/apps/mec/MecApps/MultiUEMECApp.h

@@ -0,0 +1,48 @@
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+// 
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see http://www.gnu.org/licenses/.
+// 
+
+#pragma once
+
+#include <omnetpp.h>
+#include "inet/networklayer/common/L3Address.h"
+#include "apps/mec/MecApps/MecAppBase.h"
+
+using namespace omnetpp;
+
+namespace simu5g {
+
+struct UE_MEC_CLIENT {
+    inet::L3Address address;
+    int port;
+};
+
+class MultiUEMECApp : public MecAppBase
+{
+protected:
+    virtual void handleSelfMessage(omnetpp::cMessage *msg) {};
+    virtual void handleServiceMessage(int connId) {};
+    virtual void handleMp1Message(int connId) {};
+    virtual void handleHttpMessage(int connId) {};
+    virtual void handleUeMessage(omnetpp::cMessage *msg) {};
+    virtual void established(int connId) {};
+public:
+    /**
+     * Method used to notify the MEC app that a new UE would like to associate with that
+     * Every MEC app inheriting from this class, must implement this method
+     */
+    virtual void addNewUE(struct UE_MEC_CLIENT ueData);
+};
+
+}

src/apps/mec/MecApps/MultiUEMECApp.ned

@@ -0,0 +1,56 @@
+//
+//                  Simu5G
+//
+// Authors: Giovanni Nardini, Giovanni Stea, Antonio Virdis (University of Pisa)
+//
+// This file is part of a software released under the license included in file
+// "license.pdf". Please read LICENSE and README files before using it.
+// The above files and the present reference are part of the software itself,
+// and cannot be removed from it.
+//
+
+package simu5g.apps.mec.MecApps;
+
+import inet.applications.contract.IApp;
+import simu5g.nodes.mec.MECPlatform.IMECApp;
+
+//
+// This is an empty MEC app which is used as a model for MEC apps that should
+// be shared among multiple UEs. Any shared MEC app that should extend this app 
+simple MultiUEMECApp like IMECApp, IApp
+{
+    parameters:
+        @class(simu5g::MultiUEMECApp);
+        @display("i=block/app;is=s");
+
+        int packetSize @unit(B) = default(10B);
+        string interfaceTableModule = default("");
+
+        int mecAppIndex;
+        int mecAppId;
+        int localUePort;
+
+        string mp1Address = default("");
+        int mp1Port = default(10021);
+
+		 //resource required info
+        double requiredRam @unit("B");
+        double requiredDisk @unit("B");
+        double requiredCpu;
+
+        // IApp parameters
+        int timeToLive = default(-1); // if not -1, set the TTL (IPv4) or Hop Limit (IPv6) field of sent packets to this value
+        int dscp = default(-1); // if not -1, set the DSCP (IPv4/IPv6) field of sent packets to this value
+        int tos = default(-1); // if not -1, set the Type Of Service (IPv4) / Traffic Class (IPv6) field of sent packets to this value
+
+        bool logger = default(false);
+
+    gates:
+        input mePlatformIn;
+        output mePlatformOut;
+
+        input socketIn;
+        output socketOut;
+
+}
+

src/nodes/mec/MECOrchestrator/MecOrchestrator.cc

@@ -15,6 +15,7 @@
 #include "nodes/mec/VirtualisationInfrastructureManager/VirtualisationInfrastructureManager.h"
 
 #include "nodes/mec/MECPlatform/ServiceRegistry/ServiceRegistry.h"
+#include "apps/mec/MecApps/MultiUEMECApp.h"
 
 #include "nodes/mec/MECOrchestrator/MECOMessages/MECOrchestratorMessages_m.h"
 
@@ -133,11 +134,6 @@ void MecOrchestrator::startMECApp(UALCMPMessage* msg)
 
     for(const auto& contextApp : meAppMap)
     {
-        /*
-         * TODO
-         * set the check to provide multi UE to one mec application scenario.
-         * For now the scenario is one to one, since the device application ID is used
-         */
         if(contextApp.second.mecUeAppID == ueAppID && contextApp.second.appDId.compare(contAppMsg->getAppDId()) == 0)
         {
             //        meAppMap[ueAppID].lastAckStartSeqNum = pkt->getSno();
@@ -147,7 +143,17 @@ void MecOrchestrator::startMECApp(UALCMPMessage* msg)
             EV << "MecOrchestrator::startMECApp - \tWARNING: required MEC App instance ALREADY STARTED on MEC host: " << contextApp.second.mecHost->getName() << endl;
             EV << "MecOrchestrator::startMECApp  - sending ackMEAppPacket with "<< ACK_CREATE_CONTEXT_APP << endl;
             sendCreateAppContextAck(true, contAppMsg->getRequestId(), contextApp.first);
-            return;
+            auto* existingMECApp = dynamic_cast<MultiUEMECApp*>(contextApp.second.reference);
+            if (existingMECApp) {
+                // if the app already exist and it is an app supporting multiple UEs, then notify the app about the new UE
+                struct UE_MEC_CLIENT newUE;
+                newUE.address = inet::L3Address(contAppMsg->getUeIpAddress());
+                // the UE port is not known at this stage
+                newUE.port = -1;
+                existingMECApp->addNewUE(newUE);
+            }
+            else
+                return;
         }
     }
 
@@ -266,6 +272,15 @@ void MecOrchestrator::startMECApp(UALCMPMessage* msg)
          newMecApp.mecAppPort = appInfo->endPoint.port;
          newMecApp.mecAppIsntanceId = appInfo->instanceId;
          newMecApp.contextId = contextIdCounter;
+         newMecApp.reference = appInfo->reference;
+         auto multiUEMECApp = dynamic_cast<MultiUEMECApp*>(newMecApp.reference);
+         if (multiUEMECApp) {
+             struct UE_MEC_CLIENT newUE;
+             newUE.address = inet::L3Address(contAppMsg->getUeIpAddress());
+             // the UE port is not known at this stage
+             newUE.port = -1;
+             multiUEMECApp->addNewUE(newUE);
+         }
          meAppMap[contextIdCounter] = newMecApp;
 
          MECOrchestratorMessage *msg = new MECOrchestratorMessage("MECOrchestratorMessage");

src/nodes/mec/MECOrchestrator/MecOrchestrator.h

@@ -42,6 +42,7 @@ struct mecAppMapEntry
     cModule* mecHost; // reference to the mecHost where the mec app has been deployed
     cModule* vim;       // for virtualisationInfrastructureManager methods
     cModule* mecpm;     // for mecPlatformManager methods
+    cModule* reference; // direct reference to mec app instance (omnet module)
 
     std::string ueSymbolicAddres;
     inet::L3Address ueAddress;  //for downstream using UDP Socket

src/nodes/mec/VirtualisationInfrastructureManager/VirtualisationInfrastructureManager.cc

@@ -370,6 +370,7 @@ MecAppInstanceInfo* VirtualisationInfrastructureManager::instantiateMEApp(Create
         EV << "VirtualisationInfrastructureManager::instantiateMEApp - currentMEApps: " << currentMEApps << " / " << maxMECApps << endl;
 
         instanceInfo->status = true;
+        instanceInfo->reference = module;
         return instanceInfo;
     }
     else

src/nodes/mec/VirtualisationInfrastructureManager/VirtualisationInfrastructureManager.h

@@ -50,6 +50,7 @@ struct MecAppInstanceInfo
     bool status;
     std::string instanceId;
     SockAddr endPoint;
+    cModule *reference;
 };
 
 // used to calculate processing time needed to execute a number of instructions