implemented basic PDU forwarding

src/fsfw/cfdp/pdu/AckPduCreator.cpp

@@ -0,0 +1,33 @@
+#include "AckPduCreator.h"
+
+AckPduCreator::AckPduCreator(AckInfo &ackInfo, PduConfig &pduConf)
+    : FileDirectiveCreator(pduConf, cfdp::FileDirectives::ACK, 2), ackInfo(ackInfo) {}
+
+size_t AckPduCreator::getSerializedSize() const { return FileDirectiveCreator::getWholePduSize(); }
+
+ReturnValue_t AckPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
+                                       Endianness streamEndianness) const {
+  ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
+  if (result != returnvalue::OK) {
+    return result;
+  }
+  cfdp::FileDirectives ackedDirective = ackInfo.getAckedDirective();
+  uint8_t directiveSubtypeCode = ackInfo.getDirectiveSubtypeCode();
+  cfdp::ConditionCode ackedConditionCode = ackInfo.getAckedConditionCode();
+  cfdp::AckTransactionStatus transactionStatus = ackInfo.getTransactionStatus();
+  if (ackedDirective != cfdp::FileDirectives::FINISH and
+      ackedDirective != cfdp::FileDirectives::EOF_DIRECTIVE) {
+    // TODO: better returncode
+    return returnvalue::FAILED;
+  }
+  if (*size + 2 > maxSize) {
+    return SerializeIF::BUFFER_TOO_SHORT;
+  }
+  **buffer = ackedDirective << 4 | directiveSubtypeCode;
+  *buffer += 1;
+  *size += 1;
+  **buffer = ackedConditionCode << 4 | transactionStatus;
+  *buffer += 1;
+  *size += 1;
+  return returnvalue::OK;
+}