added new command executor

src/fsfw/osal/linux/CMakeLists.txt

@@ -16,6 +16,7 @@ target_sources(${LIB_FSFW_NAME}
 		Timer.cpp
 		tcpipHelpers.cpp
 		unixUtility.cpp
+		CommandExecutor.cpp
 )
 
 find_package(Threads REQUIRED)

src/fsfw/osal/linux/CommandExecutor.cpp

@@ -0,0 +1,180 @@
+#include "CommandExecutor.h"
+
+#include "fsfw/serviceinterface.h"
+#include "fsfw/container/SimpleRingBuffer.h"
+#include "fsfw/container/DynamicFIFO.h"
+
+#include <unistd.h>
+
+#include <cstring>
+
+CommandExecutor::CommandExecutor(const size_t maxSize):
+readVec(maxSize) {
+    waiter.events = POLLIN;
+}
+
+ReturnValue_t CommandExecutor::load(std::string command, bool blocking, bool printOutput) {
+    if(state == States::PENDING) {
+        return COMMAND_PENDING;
+    }
+
+    currentCmd = command;
+    this->blocking = blocking;
+    this->printOutput = printOutput;
+    if(state == States::IDLE) {
+        state = States::COMMAND_LOADED;
+    }
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+ReturnValue_t CommandExecutor::execute() {
+    if(state == States::IDLE) {
+        return NO_COMMAND_LOADED_OR_PENDING;
+    }
+    else if(state == States::PENDING) {
+        return COMMAND_PENDING;
+    }
+    currentCmdFile = popen(currentCmd.c_str(), "r");
+    if(currentCmdFile == nullptr) {
+        lastError = errno;
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
+    if(blocking) {
+        return executeBlocking();
+    }
+    else {
+        currentFd = fileno(currentCmdFile);
+        waiter.fd = currentFd;
+    }
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+ReturnValue_t CommandExecutor::close() {
+    if(state == States::PENDING) {
+        // Attempt to close process, irrespective of if it is running or not
+        if(currentCmdFile != nullptr) {
+            pclose(currentCmdFile);
+        }
+    }
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+void CommandExecutor::printLastError(std::string funcName) const {
+    if(lastError != 0) {
+        sif::error << funcName << " pclose failed with code " <<
+                lastError << ": " << strerror(lastError) << std::endl;
+    }
+}
+
+void CommandExecutor::setRingBuffer(SimpleRingBuffer *ringBuffer,
+        DynamicFIFO<uint16_t>* sizesFifo) {
+    this->ringBuffer = ringBuffer;
+    this->sizesFifo = sizesFifo;
+}
+
+ReturnValue_t CommandExecutor::check(bool& bytesRead) {
+    if(blocking) {
+        return HasReturnvaluesIF::RETURN_OK;
+    }
+    switch(state) {
+    case(States::IDLE):
+    case(States::COMMAND_LOADED): {
+        return NO_COMMAND_LOADED_OR_PENDING;
+    }
+    case(States::PENDING): {
+        break;
+    }
+    }
+
+    int result = poll(&waiter, 1, 0);
+    switch(result) {
+    case(0): {
+        return HasReturnvaluesIF::RETURN_OK;
+        break;
+    }
+    case(1): {
+        if (waiter.revents & POLLIN) {
+            ssize_t readBytes = read(currentFd, readVec.data(), readVec.size());
+            if(readBytes == 0) {
+                // Should not happen
+                sif::warning << "CommandExecutor::check: "
+                        "No bytes read after poll event.." << std::endl;
+                break;
+            }
+            else if(readBytes > 0) {
+                bytesRead = true;
+                if(printOutput) {
+                    // It is assumed the command output is line terminated
+                    sif::info << currentCmd << " | " << readVec.data();
+                }
+                if(ringBuffer != nullptr) {
+                    ringBuffer->writeData(reinterpret_cast<const uint8_t*>(
+                            readVec.data()), readBytes);
+                }
+                if(sizesFifo != nullptr) {
+                    if(not sizesFifo->full()) {
+                        sizesFifo->insert(readBytes);
+                    }
+                }
+                return BYTES_READ;
+            }
+            else {
+                // Should also not happen
+                sif::warning << "CommandExecutor::check: Error " << errno << ": " <<
+                        strerror(errno) << std::endl;
+            }
+        }
+        else if(waiter.revents & POLLERR) {
+            sif::warning << "CommandExecuter::check: Poll error" << std::endl;
+            return COMMAND_ERROR;
+        }
+        else if(waiter.revents & POLLHUP) {
+            int result = pclose(currentCmdFile);
+            if(result != 0) {
+                lastError = result;
+                return HasReturnvaluesIF::RETURN_FAILED;
+            }
+            state = States::IDLE;
+            currentCmdFile = nullptr;
+            currentFd = 0;
+            return EXECUTION_FINISHED;
+        }
+        break;
+    }
+    }
+    return HasReturnvaluesIF::RETURN_OK;
+}
+
+void CommandExecutor::reset() {
+    CommandExecutor::close();
+    currentCmdFile = nullptr;
+    currentFd = 0;
+    state = States::IDLE;
+}
+
+int CommandExecutor::getLastError() const {
+    return this->lastError;
+}
+
+ReturnValue_t CommandExecutor::executeBlocking() {
+    while(fgets(readVec.data(), readVec.size(), currentCmdFile) != nullptr) {
+        std::string output(readVec.data());
+        if(printOutput) {
+            sif::info << currentCmd << " | " << output;
+        }
+        if(ringBuffer != nullptr) {
+            ringBuffer->writeData(reinterpret_cast<const uint8_t*>(output.data()), output.size());
+        }
+        if(sizesFifo != nullptr) {
+            if(not sizesFifo->full()) {
+                sizesFifo->insert(output.size());
+            }
+        }
+    }
+    int result = pclose(currentCmdFile);
+    if(result != 0) {
+        lastError = result;
+        return HasReturnvaluesIF::RETURN_FAILED;
+    }
+    return EXECUTION_FINISHED;
+}

src/fsfw/osal/linux/CommandExecutor.h

@@ -0,0 +1,133 @@
+#ifndef FSFW_SRC_FSFW_OSAL_LINUX_COMMANDEXECUTOR_H_
+#define FSFW_SRC_FSFW_OSAL_LINUX_COMMANDEXECUTOR_H_
+
+#include "fsfw/returnvalues/HasReturnvaluesIF.h"
+#include "fsfw/returnvalues/FwClassIds.h"
+
+#include <poll.h>
+
+#include <string>
+#include <vector>
+
+class SimpleRingBuffer;
+template <typename T> class DynamicFIFO;
+
+/**
+ * @brief   Helper class to execute shell commands in blocking and non-blocking mode
+ * @details
+ * This class is able to execute processes by using the Linux popen call. It also has the
+ * capability of writing the read output of a process into a provided ring buffer.
+ *
+ * The executor works by first loading the command which should be executed and specifying
+ * whether it should be executed blocking or non-blocking. After that, execution can be started
+ * with the execute command. In blocking mode, the execute command will block until the command
+ * has finished
+ */
+class CommandExecutor {
+public:
+    enum class States {
+        IDLE,
+        COMMAND_LOADED,
+        PENDING
+    };
+
+    static constexpr uint8_t CLASS_ID = CLASS_ID::LINUX_OSAL;
+
+    //! [EXPORT] : [COMMENT] Execution of the current command has finished
+    static constexpr ReturnValue_t EXECUTION_FINISHED =
+            HasReturnvaluesIF::makeReturnCode(CLASS_ID, 0);
+
+    //! [EXPORT] : [COMMENT] Command is pending. This will also be returned if the user tries
+    //! to load another command but a command is still pending
+    static constexpr ReturnValue_t COMMAND_PENDING =
+            HasReturnvaluesIF::makeReturnCode(CLASS_ID, 1);
+    //! [EXPORT] : [COMMENT] Some bytes have been read from the executing process
+    static constexpr ReturnValue_t BYTES_READ =
+            HasReturnvaluesIF::makeReturnCode(CLASS_ID, 2);
+    //! [EXPORT] : [COMMENT] Command execution failed
+    static constexpr ReturnValue_t COMMAND_ERROR =
+            HasReturnvaluesIF::makeReturnCode(CLASS_ID, 3);
+    //! [EXPORT] : [COMMENT]
+    static constexpr ReturnValue_t NO_COMMAND_LOADED_OR_PENDING =
+            HasReturnvaluesIF::makeReturnCode(CLASS_ID, 4);
+    static constexpr ReturnValue_t PCLOSE_CALL_ERROR =
+            HasReturnvaluesIF::makeReturnCode(CLASS_ID, 6);
+
+    /**
+     * Constructor. Is initialized with maximum size of internal buffer to read data from the
+     * executed process.
+     * @param maxSize
+     */
+    CommandExecutor(const size_t maxSize);
+
+    /**
+     * Load a new command which should be executed
+     * @param command
+     * @param blocking
+     * @param printOutput
+     * @return
+     */
+    ReturnValue_t load(std::string command, bool blocking, bool printOutput = true);
+    /**
+     * Execute the loaded command.
+     * @return
+     *  - In blocking mode, it will return RETURN_FAILED if
+     *    the result of the system call was not 0. The error value can be accessed using
+     *    getLastError
+     *  - In non-blocking mode, this call will start
+     *    the execution and then return RETURN_OK
+     */
+    ReturnValue_t execute();
+    /**
+     * Only used in non-blocking mode. Checks the currently running command.
+     * @param bytesRead Will be set to the number of bytes read, if bytes have been read
+     * @return
+     *  - BYTES_READ if bytes have been read from the executing process. It is recommended to call
+     *    check again after this
+     *  - RETURN_OK execution is pending, but no bytes have been read from the executing process
+     *  - RETURN_FAILED if execution has failed, error value can be accessed using getLastError
+     *  - EXECUTION_FINISHED if the process was executed successfully
+     *  - COMMAND_ERROR internal poll error
+     */
+    ReturnValue_t check(bool& bytesRead);
+    /**
+     * Abort the current command. Should normally not be necessary, check can be used to find
+     * out whether command execution was successful
+     * @return RETURN_OK
+     */
+    ReturnValue_t close();
+
+    int getLastError() const;
+    void printLastError(std::string funcName) const;
+
+    /**
+     * Assign a ring buffer and a FIFO which will be filled by the executor with the output
+     * read from the started process
+     * @param ringBuffer
+     * @param sizesFifo
+     */
+    void setRingBuffer(SimpleRingBuffer* ringBuffer, DynamicFIFO<uint16_t>* sizesFifo);
+
+    /**
+     * Reset the executor. This calls close internally and then reset the state machine so new
+     * commands can be loaded and executed
+     */
+    void reset();
+private:
+    std::string currentCmd;
+    bool blocking = true;
+    FILE* currentCmdFile = nullptr;
+    int currentFd = 0;
+    bool printOutput = true;
+    std::vector<char> readVec;
+    struct pollfd waiter {};
+    SimpleRingBuffer* ringBuffer = nullptr;
+    DynamicFIFO<uint16_t>* sizesFifo = nullptr;
+
+    States state = States::IDLE;
+    int lastError = 0;
+
+    ReturnValue_t executeBlocking();
+};
+
+#endif /* FSFW_SRC_FSFW_OSAL_LINUX_COMMANDEXECUTOR_H_ */

src/fsfw/returnvalues/FwClassIds.h

@@ -72,6 +72,7 @@ enum: uint8_t {
     PUS_SERVICE_3, //PUS3
     PUS_SERVICE_9, //PUS9
     FILE_SYSTEM, //FILS
+    LINUX_OSAL, //UXOS
     HAL_SPI, //HSPI
     HAL_UART, //HURT
     HAL_I2C, //HI2C