src/fsfw/osal/common/TcpTmTcServer.cpp

@@ -1,8 +1,11 @@
-#include "fsfw/osal/common/TcpTmTcServer.h"
-#include "fsfw/osal/common/TcpTmTcBridge.h"
-#include "fsfw/osal/common/tcpipHelpers.h"
-
 #include "fsfw/platform.h"
+#include "fsfw/FSFW.h"
+
+#include "TcpTmTcServer.h"
+#include "TcpTmTcBridge.h"
+#include "tcpipHelpers.h"
+
+#include "fsfw/tasks/TaskFactory.h"
 #include "fsfw/container/SharedRingBuffer.h"
 #include "fsfw/ipc/MessageQueueSenderIF.h"
 #include "fsfw/ipc/MutexGuard.h"
@@ -17,6 +20,7 @@
 #elif defined(PLATFORM_UNIX)
 #include <netdb.h>
 #endif
+#include <chrono>
 
 #ifndef FSFW_TCP_RECV_WIRETAPPING_ENABLED
 #define FSFW_TCP_RECV_WIRETAPPING_ENABLED 0
@@ -25,12 +29,11 @@
 const std::string TcpTmTcServer::DEFAULT_SERVER_PORT = tcpip::DEFAULT_SERVER_PORT;
 
 TcpTmTcServer::TcpTmTcServer(object_id_t objectId, object_id_t tmtcTcpBridge,
-        size_t receptionBufferSize, std::string customTcpServerPort):
-        SystemObject(objectId), tmtcBridgeId(tmtcTcpBridge),
-        tcpPort(customTcpServerPort), receptionBuffer(receptionBufferSize) {
-    if(tcpPort == "") {
-        tcpPort = DEFAULT_SERVER_PORT;
-    }
+        size_t receptionBufferSize, size_t ringBufferSize, std::string customTcpServerPort,
+        ReceptionModes receptionMode):
+        SystemObject(objectId), tmtcBridgeId(tmtcTcpBridge), receptionMode(receptionMode),
+        tcpConfig(customTcpServerPort), receptionBuffer(receptionBufferSize),
+        ringBuffer(ringBufferSize, true), validPacketIds() {
 }
 
 ReturnValue_t TcpTmTcServer::initialize() {
@@ -41,6 +44,16 @@ ReturnValue_t TcpTmTcServer::initialize() {
         return result;
     }
 
+    switch(receptionMode) {
+    case(ReceptionModes::SPACE_PACKETS): {
+        spacePacketParser = new SpacePacketParser(validPacketIds);
+        if(spacePacketParser == nullptr) {
+            return HasReturnvaluesIF::RETURN_FAILED;
+        }
+        tcpConfig.tcpFlags |= MSG_DONTWAIT;
+    }
+    }
+
     tcStore = ObjectManager::instance()->get<StorageManagerIF>(objects::TC_STORE);
     if (tcStore == nullptr) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
@@ -63,7 +76,7 @@ ReturnValue_t TcpTmTcServer::initialize() {
     hints.ai_flags = AI_PASSIVE;
 
     // Listen to all addresses (0.0.0.0) by using AI_PASSIVE in the hint flags
-    retval = getaddrinfo(nullptr, tcpPort.c_str(), &hints, &addrResult);
+    retval = getaddrinfo(nullptr, tcpConfig.tcpPort.c_str(), &hints, &addrResult);
     if (retval != 0) {
         handleError(Protocol::TCP, ErrorSources::GETADDRINFO_CALL);
         return HasReturnvaluesIF::RETURN_FAILED;
@@ -105,7 +118,7 @@ ReturnValue_t TcpTmTcServer::performOperation(uint8_t opCode) {
 
     // Listen for connection requests permanently for lifetime of program
     while(true) {
-        retval = listen(listenerTcpSocket, tcpBacklog);
+        retval = listen(listenerTcpSocket, tcpConfig.tcpBacklog);
         if(retval == SOCKET_ERROR) {
             handleError(Protocol::TCP, ErrorSources::LISTEN_CALL, 500);
             continue;
@@ -123,11 +136,12 @@ ReturnValue_t TcpTmTcServer::performOperation(uint8_t opCode) {
         handleServerOperation(connSocket);
 
         // Done, shut down connection and go back to listening for client requests
-        retval = shutdown(connSocket, SHUT_SEND);
+        retval = shutdown(connSocket, SHUT_BOTH);
         if(retval != 0) {
             handleError(Protocol::TCP, ErrorSources::SHUTDOWN_CALL);
         }
         closeSocket(connSocket);
+        connSocket = 0;
     }
     return HasReturnvaluesIF::RETURN_OK;
 }
@@ -144,51 +158,82 @@ ReturnValue_t TcpTmTcServer::initializeAfterTaskCreation() {
     return HasReturnvaluesIF::RETURN_OK;
 }
 
-void TcpTmTcServer::handleServerOperation(socket_t connSocket) {
-    int retval = 0;
-    do {
-        // Read all telecommands sent by the client
-        retval = recv(connSocket,
+void TcpTmTcServer::handleServerOperation(socket_t& connSocket) {
+    while (true) {
+        int retval = recv(
+                connSocket,
                 reinterpret_cast<char*>(receptionBuffer.data()),
                 receptionBuffer.capacity(),
-                tcpFlags);
-        if (retval > 0) {
-            handleTcReception(retval);
+                tcpConfig.tcpFlags
+        );
+        if(retval == 0) {
+            // Client closed connection
+            return;
         }
-        else if(retval == 0) {
-            // Client has finished sending telecommands, send telemetry now
-            handleTmSending(connSocket);
+        else if(retval > 0) {
+            // The ring buffer was configured for overwrite, so the returnvalue does not need to
+            // be checked for now
+            ringBuffer.writeData(receptionBuffer.data(), retval);
         }
-        else {
-            // Should not happen
-            tcpip::handleError(tcpip::Protocol::TCP, tcpip::ErrorSources::RECV_CALL);
+        else if(retval < 0)  {
+            if(errno == EAGAIN) {
+                // No data available. Check whether any packets have been read, then send back
+                // telemetry if available
+                bool tcAvailable = false;
+                bool tmSent = false;
+                size_t availableReadData = ringBuffer.getAvailableReadData();
+                if(availableReadData > lastRingBufferSize) {
+                    tcAvailable = true;
+                    handleTcRingBufferData(availableReadData);
+                }
+                ReturnValue_t result = handleTmSending(connSocket, tmSent);
+                if(result == CONN_BROKEN) {
+                    return;
+                }
+                if(not tcAvailable and not tmSent) {
+                    TaskFactory::delayTask(DEFAULT_LOOP_DELAY_MS);
+                }
+            }
+            else {
+                tcpip::handleError(tcpip::Protocol::TCP, tcpip::ErrorSources::RECV_CALL);
+            }
         }
-    } while(retval > 0);
+    }
 }
 
-ReturnValue_t TcpTmTcServer::handleTcReception(size_t bytesRecvd) {
+ReturnValue_t TcpTmTcServer::handleTcReception(uint8_t* spacePacket, size_t packetSize) {
 #if FSFW_TCP_RECV_WIRETAPPING_ENABLED == 1
     arrayprinter::print(receptionBuffer.data(), bytesRead);
 #endif
+    if(spacePacket == nullptr or packetSize == 0) {
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
     store_address_t storeId;
-    ReturnValue_t result = tcStore->addData(&storeId, receptionBuffer.data(), bytesRecvd);
+    ReturnValue_t result = tcStore->addData(&storeId, spacePacket, packetSize);
     if (result != HasReturnvaluesIF::RETURN_OK) {
 #if FSFW_VERBOSE_LEVEL >= 1
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-        sif::warning<< "TcpTmTcServer::handleServerOperation: Data storage failed." << std::endl;
-        sif::warning << "Packet size: " << bytesRecvd << std::endl;
+        sif::warning << "TcpTmTcServer::handleServerOperation: Data storage with packet size" <<
+                packetSize << " failed" << std::endl;
+#else
+        sif::printWarning("TcpTmTcServer::handleServerOperation: Data storage with packet size %d "
+                "failed\n", packetSize);
 #endif /* FSFW_CPP_OSTREAM_ENABLED == 1 */
 #endif /* FSFW_VERBOSE_LEVEL >= 1 */
+        return result;
     }
 
     TmTcMessage message(storeId);
 
-    result  = MessageQueueSenderIF::sendMessage(targetTcDestination, &message);
+    result = MessageQueueSenderIF::sendMessage(targetTcDestination, &message);
     if (result != HasReturnvaluesIF::RETURN_OK) {
 #if FSFW_VERBOSE_LEVEL >= 1
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-        sif::warning << "UdpTcPollingTask::handleSuccessfullTcRead: "
+        sif::warning << "TcpTmTcServer::handleServerOperation: "
                 " Sending message to queue failed" << std::endl;
+#else
+        sif::printWarning("TcpTmTcServer::handleServerOperation: "
+                " Sending message to queue failed\n");
 #endif /* FSFW_CPP_OSTREAM_ENABLED == 1 */
 #endif /* FSFW_VERBOSE_LEVEL >= 1 */
         tcStore->deleteData(storeId);
@@ -196,21 +241,26 @@ ReturnValue_t TcpTmTcServer::handleTcReception(size_t bytesRecvd) {
     return result;
 }
 
-void TcpTmTcServer::setTcpBacklog(uint8_t tcpBacklog) {
-    this->tcpBacklog = tcpBacklog;
-}
-
 std::string TcpTmTcServer::getTcpPort() const {
-    return tcpPort;
+    return tcpConfig.tcpPort;
 }
 
-ReturnValue_t TcpTmTcServer::handleTmSending(socket_t connSocket) {
+void TcpTmTcServer::setSpacePacketParsingOptions(std::vector<uint16_t> validPacketIds) {
+    this->validPacketIds = validPacketIds;
+}
+
+TcpTmTcServer::TcpConfig& TcpTmTcServer::getTcpConfigStruct() {
+    return tcpConfig;
+}
+
+ReturnValue_t TcpTmTcServer::handleTmSending(socket_t connSocket, bool& tmSent) {
     // Access to the FIFO is mutex protected because it is filled by the bridge
     MutexGuard(tmtcBridge->mutex, tmtcBridge->timeoutType, tmtcBridge->mutexTimeoutMs);
     store_address_t storeId;
     while((not tmtcBridge->tmFifo->empty()) and
             (tmtcBridge->packetSentCounter < tmtcBridge->sentPacketsPerCycle)) {
-        tmtcBridge->tmFifo->retrieve(&storeId);
+        // Send can fail, so only peek from the FIFO
+        tmtcBridge->tmFifo->peek(&storeId);
 
         // Using the store accessor will take care of deleting TM from the store automatically
         ConstStorageAccessor storeAccessor(storeId);
@@ -221,10 +271,101 @@ ReturnValue_t TcpTmTcServer::handleTmSending(socket_t connSocket) {
         int retval = send(connSocket,
                 reinterpret_cast<const char*>(storeAccessor.data()),
                 storeAccessor.size(),
-                tcpTmFlags);
-        if(retval != static_cast<int>(storeAccessor.size())) {
-            tcpip::handleError(tcpip::Protocol::TCP, tcpip::ErrorSources::SEND_CALL);
+                tcpConfig.tcpTmFlags);
+        if(retval == static_cast<int>(storeAccessor.size())) {
+            // Packet sent, clear FIFO entry
+            tmtcBridge->tmFifo->pop();
+            tmSent = true;
+
+        }
+        else if(retval <= 0) {
+            // Assume that the client has closed the connection here for now
+            handleSocketError(storeAccessor);
+            return CONN_BROKEN;
         }
     }
     return HasReturnvaluesIF::RETURN_OK;
 }
+
+ReturnValue_t TcpTmTcServer::handleTcRingBufferData(size_t availableReadData) {
+    ReturnValue_t status = HasReturnvaluesIF::RETURN_OK;
+    ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
+    size_t readAmount = availableReadData;
+    lastRingBufferSize = availableReadData;
+    if(readAmount >= ringBuffer.getMaxSize()) {
+#if FSFW_VERBOSE_LEVEL >= 1
+#if FSFW_CPP_OSTREAM_ENABLED == 1
+        // Possible configuration error, too much data or/and data coming in too fast,
+        // requiring larger buffers
+        sif::warning << "TcpTmTcServer::handleServerOperation: Ring buffer reached " <<
+                "fill count" << std::endl;
+#else
+        sif::printWarning("TcpTmTcServer::handleServerOperation: Ring buffer reached "
+                "fill count");
+#endif
+#endif
+    }
+    if(readAmount >= receptionBuffer.size()) {
+#if FSFW_VERBOSE_LEVEL >= 1
+#if FSFW_CPP_OSTREAM_ENABLED == 1
+        // Possible configuration error, too much data or/and data coming in too fast,
+        // requiring larger buffers
+        sif::warning << "TcpTmTcServer::handleServerOperation: "
+                "Reception buffer too small " << std::endl;
+#else
+        sif::printWarning("TcpTmTcServer::handleServerOperation: Reception buffer too small\n");
+#endif
+#endif
+        readAmount = receptionBuffer.size();
+    }
+    ringBuffer.readData(receptionBuffer.data(), readAmount, true);
+    const uint8_t* bufPtr = receptionBuffer.data();
+    const uint8_t** bufPtrPtr = &bufPtr;
+    size_t startIdx = 0;
+    size_t foundSize = 0;
+    size_t readLen = 0;
+    while(readLen < readAmount) {
+        result = spacePacketParser->parseSpacePackets(bufPtrPtr, readAmount,
+                startIdx, foundSize, readLen);
+        switch(result) {
+        case(SpacePacketParser::NO_PACKET_FOUND):
+        case(SpacePacketParser::SPLIT_PACKET): {
+            break;
+        }
+        case(HasReturnvaluesIF::RETURN_OK): {
+            result = handleTcReception(receptionBuffer.data() + startIdx, foundSize);
+            if(result != HasReturnvaluesIF::RETURN_OK) {
+                status = result;
+            }
+        }
+        }
+        ringBuffer.deleteData(foundSize);
+        lastRingBufferSize = ringBuffer.getAvailableReadData();
+        std::memset(receptionBuffer.data() + startIdx, 0, foundSize);
+    }
+    return status;
+}
+
+void TcpTmTcServer::handleSocketError(ConstStorageAccessor &accessor) {
+    // Don't delete data
+    accessor.release();
+    auto socketError = getLastSocketError();
+    switch(socketError) {
+#if defined PLATFORM_WIN
+    case(WSAECONNRESET): {
+        // See https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-send
+        // Remote client might have shut down connection
+        return;
+    }
+#else
+    case(EPIPE): {
+        // See https://man7.org/linux/man-pages/man2/send.2.html
+        // Remote client might have shut down connection
+        return;
+    }
+#endif
+    default: {
+        tcpip::handleError(tcpip::Protocol::TCP, tcpip::ErrorSources::SEND_CALL);
+    }
+    }
+}

src/fsfw/osal/common/TcpTmTcServer.h

@@ -1,11 +1,13 @@
 #ifndef FSFW_OSAL_COMMON_TCP_TMTC_SERVER_H_
 #define FSFW_OSAL_COMMON_TCP_TMTC_SERVER_H_
 
+#include <fsfw/tmtcservices/SpacePacketParser.h>
 #include "TcpIpBase.h"
 
 #include "fsfw/platform.h"
 #include "fsfw/osal/common/tcpipHelpers.h"
 #include "fsfw/ipc/messageQueueDefinitions.h"
+#include "fsfw/container/SimpleRingBuffer.h"
 #include "fsfw/ipc/MessageQueueIF.h"
 #include "fsfw/objectmanager/frameworkObjects.h"
 #include "fsfw/objectmanager/SystemObject.h"
@@ -42,9 +44,37 @@ class TcpTmTcServer:
         public TcpIpBase,
         public ExecutableObjectIF {
 public:
+    enum class ReceptionModes {
+        SPACE_PACKETS
+    };
+
+    struct TcpConfig {
+    public:
+        TcpConfig(std::string tcpPort): tcpPort(tcpPort) {}
+
+        /**
+         * Passed to the recv call
+         */
+        int tcpFlags = 0;
+        int tcpBacklog = 3;
+
+        /**
+         * Passed to the select call which is used to ensure non-blocking TC reception
+         */
+        //uint32_t selectTimeoutMs = DEFAULT_SELECT_TIMEOUT_MS;
+        /**
+         * Passed to the send call
+         */
+        int tcpTmFlags = 0;
+
+        const std::string tcpPort;
+    };
+
     static const std::string DEFAULT_SERVER_PORT;
 
     static constexpr size_t ETHERNET_MTU_SIZE = 1500;
+    static constexpr size_t RING_BUFFER_SIZE = ETHERNET_MTU_SIZE * 3;
+    static constexpr uint32_t DEFAULT_LOOP_DELAY_MS = 200;
 
     /**
      * TCP Server Constructor
@@ -55,11 +85,19 @@ public:
      * @param customTcpServerPort   The user can specify another port than the default (7301) here.
      */
     TcpTmTcServer(object_id_t objectId, object_id_t tmtcTcpBridge,
-            size_t receptionBufferSize = ETHERNET_MTU_SIZE + 1,
-            std::string customTcpServerPort = "");
+            size_t receptionBufferSize = RING_BUFFER_SIZE,
+            size_t ringBufferSize = RING_BUFFER_SIZE,
+            std::string customTcpServerPort = DEFAULT_SERVER_PORT,
+            ReceptionModes receptionMode = ReceptionModes::SPACE_PACKETS);
     virtual~ TcpTmTcServer();
 
-    void setTcpBacklog(uint8_t tcpBacklog);
+    /**
+     * Get a handle to the TCP configuration struct, which can be used to configure TCP
+     * properties
+     * @return
+     */
+    TcpConfig& getTcpConfigStruct();
+    void setSpacePacketParsingOptions(std::vector<uint16_t> validPacketIds);
 
     ReturnValue_t initialize() override;
     ReturnValue_t performOperation(uint8_t opCode) override;
@@ -71,25 +109,29 @@ protected:
     StorageManagerIF* tcStore = nullptr;
     StorageManagerIF* tmStore = nullptr;
 private:
+    static constexpr ReturnValue_t CONN_BROKEN = HasReturnvaluesIF::makeReturnCode(1, 0);
     //! TMTC bridge is cached.
     object_id_t tmtcBridgeId = objects::NO_OBJECT;
     TcpTmTcBridge* tmtcBridge = nullptr;
 
-    std::string tcpPort;
-    int tcpFlags = 0;
-    socket_t listenerTcpSocket = 0;
+    ReceptionModes receptionMode;
+    TcpConfig tcpConfig;
     struct sockaddr tcpAddress;
+    socket_t listenerTcpSocket = 0;
+
     MessageQueueId_t targetTcDestination = MessageQueueIF::NO_QUEUE;
-    int tcpAddrLen = sizeof(tcpAddress);
-    int tcpBacklog = 3;
 
     std::vector<uint8_t> receptionBuffer;
-    int tcpSockOpt = 0;
-    int tcpTmFlags = 0;
+    SimpleRingBuffer ringBuffer;
+    std::vector<uint16_t> validPacketIds;
+    SpacePacketParser* spacePacketParser = nullptr;
+    uint8_t lastRingBufferSize = 0;
 
-    void handleServerOperation(socket_t connSocket);
-    ReturnValue_t handleTcReception(size_t bytesRecvd);
-    ReturnValue_t handleTmSending(socket_t connSocket);
+    virtual void handleServerOperation(socket_t& connSocket);
+    ReturnValue_t handleTcReception(uint8_t* spacePacket, size_t packetSize);
+    ReturnValue_t handleTmSending(socket_t connSocket, bool& tmSent);
+    ReturnValue_t handleTcRingBufferData(size_t availableReadData);
+    void handleSocketError(ConstStorageAccessor& accessor);
 };
 
 #endif /* FSFW_OSAL_COMMON_TCP_TMTC_SERVER_H_ */

src/fsfw/tmtcpacket/SpacePacket.h

@@ -15,56 +15,67 @@
  */
 class SpacePacket: public SpacePacketBase {
 public:
-	static const uint16_t PACKET_MAX_SIZE = 1024;
-	/**
-	 * The constructor initializes the packet and sets all header information
-	 * according to the passed parameters.
-	 * @param packetDataLength Sets the packet data length field and therefore specifies the size of the packet.
-	 * @param isTelecommand Sets the packet type field to either TC (true) or TM (false).
-	 * @param apid Sets the packet's APID field. The default value describes an idle packet.
-	 * @param sequenceCount ets the packet's Source Sequence Count field.
-	 */
-	SpacePacket(uint16_t packetDataLength, bool isTelecommand = false,
-			uint16_t apid = APID_IDLE_PACKET, uint16_t sequenceCount = 0);
-	/**
-	 * The class's default destructor.
-	 */
-	virtual ~SpacePacket();
-	/**
-	 * With this call, the complete data content (including the CCSDS Primary
-	 * Header) is overwritten with the byte stream given.
-	 * @param p_data		Pointer to data to overwrite the content with
-	 * @param packet_size	Size of the data
-	 * @return	@li	\c true if packet_size is smaller than \c MAX_PACKET_SIZE.
-	 * 			@li \c false else.
-	 */
-	bool addWholeData(const uint8_t* p_data, uint32_t packet_size);
+    static const uint16_t PACKET_MAX_SIZE = 1024;
+    /**
+     * The constructor initializes the packet and sets all header information
+     * according to the passed parameters.
+     * @param packetDataLength Sets the packet data length field and therefore specifies
+     * the size of the packet.
+     * @param isTelecommand Sets the packet type field to either TC (true) or TM (false).
+     * @param apid Sets the packet's APID field. The default value describes an idle packet.
+     * @param sequenceCount ets the packet's Source Sequence Count field.
+     */
+    SpacePacket(uint16_t packetDataLength, bool isTelecommand = false,
+            uint16_t apid = APID_IDLE_PACKET, uint16_t sequenceCount = 0);
+    /**
+     * The class's default destructor.
+     */
+    virtual ~SpacePacket();
+
+    static constexpr uint16_t getTcSpacePacketIdFromApid(uint16_t apid) {
+        uint16_t tcPacketId = (0x18 << 8) | (((apid >> 8) & 0x07) << 8) | (apid & 0x00ff);
+        return tcPacketId;
+    }
+    static constexpr uint16_t getTmSpacePacketIdFromApid(uint16_t apid) {
+        uint16_t tmPacketId = (0x08 << 8) | (((apid >> 8) & 0x07) << 8) | (apid & 0x00ff);
+        return tmPacketId;
+    }
+
+    /**
+     * With this call, the complete data content (including the CCSDS Primary
+     * Header) is overwritten with the byte stream given.
+     * @param p_data		Pointer to data to overwrite the content with
+     * @param packet_size	Size of the data
+     * @return	@li	\c true if packet_size is smaller than \c MAX_PACKET_SIZE.
+     * 			@li \c false else.
+     */
+    bool addWholeData(const uint8_t* p_data, uint32_t packet_size);
 protected:
-	/**
-	 * This structure defines the data structure of a Space Packet as local data.
-	 * There's a buffer which corresponds to the Space Packet Data Field with a
-	 * maximum size of \c PACKET_MAX_SIZE.
-	 */
-	struct PacketStructured {
-		CCSDSPrimaryHeader header;
-		uint8_t buffer[PACKET_MAX_SIZE];
-	};
-	/**
-	 * This union simplifies accessing the full data content of the Space Packet.
-	 * This is achieved by putting the \c PacketStructured struct in a union with
-	 * a plain buffer.
-	 */
-	union SpacePacketData {
-		PacketStructured fields;
-		uint8_t byteStream[PACKET_MAX_SIZE + sizeof(CCSDSPrimaryHeader)];
-	};
-	/**
-	 * This is the data representation of the class.
-	 * It is a struct of CCSDS Primary Header and a data field, which again is
-	 * packed in an union, so the data can be accessed as a byte stream without
-	 * a cast.
-	 */
-	SpacePacketData localData;
+    /**
+     * This structure defines the data structure of a Space Packet as local data.
+     * There's a buffer which corresponds to the Space Packet Data Field with a
+     * maximum size of \c PACKET_MAX_SIZE.
+     */
+    struct PacketStructured {
+        CCSDSPrimaryHeader header;
+        uint8_t buffer[PACKET_MAX_SIZE];
+    };
+    /**
+     * This union simplifies accessing the full data content of the Space Packet.
+     * This is achieved by putting the \c PacketStructured struct in a union with
+     * a plain buffer.
+     */
+    union SpacePacketData {
+        PacketStructured fields;
+        uint8_t byteStream[PACKET_MAX_SIZE + sizeof(CCSDSPrimaryHeader)];
+    };
+    /**
+     * This is the data representation of the class.
+     * It is a struct of CCSDS Primary Header and a data field, which again is
+     * packed in an union, so the data can be accessed as a byte stream without
+     * a cast.
+     */
+    SpacePacketData localData;
 };
 
 #endif /* SPACEPACKET_H_ */

src/fsfw/tmtcservices/SpacePacketParser.cpp

@@ -0,0 +1,77 @@
+#include <fsfw/serviceinterface/ServiceInterface.h>
+#include <fsfw/tmtcservices/SpacePacketParser.h>
+#include <algorithm>
+
+SpacePacketParser::SpacePacketParser(std::vector<uint16_t> validPacketIds):
+        validPacketIds(validPacketIds) {
+}
+
+ReturnValue_t SpacePacketParser::parseSpacePackets(const uint8_t *buffer,
+        const size_t maxSize, size_t& startIndex, size_t& foundSize) {
+    const uint8_t** tempPtr = &buffer;
+    size_t readLen = 0;
+    return parseSpacePackets(tempPtr, maxSize, startIndex, foundSize, readLen);
+}
+
+ReturnValue_t SpacePacketParser::parseSpacePackets(const uint8_t **buffer, const size_t maxSize,
+        size_t &startIndex, size_t &foundSize, size_t& readLen) {
+    if(buffer == nullptr or maxSize < 5) {
+#if FSFW_CPP_OSTREAM_ENABLED == 1
+        sif::warning << "SpacePacketParser::parseSpacePackets: Frame invalid" << std::endl;
+#else
+        sif::printWarning("SpacePacketParser::parseSpacePackets: Frame invalid\n");
+#endif
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
+    const uint8_t* bufPtr = *buffer;
+
+    auto verifyLengthField = [&](size_t idx) {
+        uint16_t lengthField = bufPtr[idx + 4] << 8 | bufPtr[idx + 5];
+        size_t packetSize = lengthField + 7;
+        startIndex = idx;
+        ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
+        if(lengthField == 0) {
+            // Skip whole header for now
+            foundSize = 6;
+            result = NO_PACKET_FOUND;
+        }
+        else if(packetSize + idx > maxSize) {
+            // Don't increment buffer and read length here, user has to decide what to do
+            foundSize = packetSize;
+            return SPLIT_PACKET;
+        }
+        else {
+            foundSize = packetSize;
+        }
+        *buffer += foundSize;
+        readLen += foundSize;
+        return result;
+    };
+
+    size_t idx = 0;
+    // Space packet ID as start marker
+    if(validPacketIds.size() > 0) {
+        while(idx < maxSize - 5) {
+            uint16_t currentPacketId = bufPtr[idx] << 8 | bufPtr[idx + 1];
+            if(std::find(validPacketIds.begin(), validPacketIds.end(), currentPacketId) !=
+                    validPacketIds.end()) {
+                if(idx + 5 >= maxSize) {
+                    return SPLIT_PACKET;
+                }
+                return verifyLengthField(idx);
+            }
+            else {
+                idx++;
+            }
+        }
+        startIndex = 0;
+        foundSize = maxSize;
+        *buffer += foundSize;
+        readLen += foundSize;
+        return NO_PACKET_FOUND;
+    }
+    // Assume that the user verified a valid start of a space packet
+    else {
+        return verifyLengthField(idx);
+    }
+}

src/fsfw/tmtcservices/SpacePacketParser.h

@@ -0,0 +1,96 @@
+#ifndef FRAMEWORK_TMTCSERVICES_PUSPARSER_H_
+#define FRAMEWORK_TMTCSERVICES_PUSPARSER_H_
+
+#include "fsfw/container/DynamicFIFO.h"
+#include "fsfw/returnvalues/FwClassIds.h"
+
+#include <utility>
+#include <cstdint>
+
+/**
+ * @brief	This small helper class scans a given buffer for PUS packets.
+ * 			Can be used if PUS packets are serialized in a tightly packed frame.
+ * @details
+ * The parser uses the length field field of the space packets to find
+ * the respective space packet sizes.
+ *
+ * The parser parses a buffer by taking a pointer and the maximum size to scan.
+ * If space packets are found, they are stored in a FIFO which stores pairs
+ * consisting of the index in the buffer and the respective packet sizes.
+ *
+ * If the parser detects split packets (which means that the size of the
+ * next packet is larger than the remaining size to scan), it can either
+ * store that split packet or throw away the packet.
+ * @author   R. Mueller
+ */
+class SpacePacketParser {
+public:
+	//! The first entry is the index inside the buffer while the second index
+	//! is the size of the PUS packet starting at that index.
+	using IndexSizePair = std::pair<size_t, size_t>;
+
+	static constexpr uint8_t INTERFACE_ID = CLASS_ID::PUS_PARSER;
+	static constexpr ReturnValue_t NO_PACKET_FOUND = MAKE_RETURN_CODE(0x00);
+	static constexpr ReturnValue_t SPLIT_PACKET = MAKE_RETURN_CODE(0x01);
+
+	/**
+	 * @brief   Parser constructor.
+	 * @param maxExpectedPusPackets
+	 * Maximum expected number of PUS packets. A good estimate is to divide
+	 * the frame size by the minimum size of a PUS packet (12 bytes)
+	 * @param storeSplitPackets
+	 * Specifies whether split packets are also stored inside the FIFO,
+	 * with the size being the remaining frame size.
+	 */
+	SpacePacketParser(std::vector<uint16_t> validPacketIds);
+
+	/**
+	 * Parse a given frame for PUS packets
+	 * @param frame
+	 * @param frameSize
+	 * @param foundPackets The number of found packets will be stored here
+	 * @return
+	 *  -@c NO_PACKET_FOUND if no packet was found
+	 *  -@c SPLIT_PACKET if splitting is enabled and a split packet was found
+	 *  -@c RETURN_OK if a packet was found. The index and sizes are stored in the internal FIFO
+	 */
+	ReturnValue_t parseSpacePackets(const uint8_t* buffer, const size_t maxSize,
+	        size_t& startIndex, size_t& foundSize);
+
+	ReturnValue_t parseSpacePackets(const uint8_t **buffer, const size_t maxSize,
+	        size_t& startIndex, size_t& foundSize, size_t& readLen);
+	/**
+	 * Accessor function to get a reference to the internal FIFO which
+	 * stores pairs of index and packet sizes. This FIFO is filled
+	 * by the #parsePusPackets function.
+	 * @return
+	 */
+	//DynamicFIFO<IndexSizePair>& fifo();
+
+	/**
+	 * Retrieve the next index and packet size pair from the FIFO.
+	 * This also removes it from the FIFO. Please note that if the FIFO
+	 * is empty, an empty pair will be returned.
+	 * @return
+	 */
+	//IndexSizePair getNextFifoPair();
+
+private:
+	/**
+	 * A FIFO is used to store information about multiple PUS packets
+	 * inside the receive buffer. The maximum number of entries is defined
+	 * by the first constructor argument.
+	 */
+	//DynamicFIFO<IndexSizePair> indexSizePairFIFO;
+
+	std::vector<uint16_t> validPacketIds;
+
+	//bool storeSplitPackets = false;
+
+//	ReturnValue_t readMultiplePackets(const uint8_t *frame, size_t frameSize,
+//			size_t startIndex, uint32_t& foundPackets);
+//	ReturnValue_t readNextPacket(const uint8_t *frame,
+//			size_t frameSize, size_t& startIndex, uint32_t& foundPackets);
+};
+
+#endif /* FRAMEWORK_TMTCSERVICES_PUSPARSER_H_ */