+int FGKissWrapper::unwrap( size_t n, uint8_t * buf )
+{
+ uint8_t * sp = buf;
+
+ // look for FEND
+ while( 0 < n && FEND != *sp ) {
+ sp++;
+ n--;
+ }
+
+ // ignore all leading FEND
+ while( 0 < n && FEND == *sp ) {
+ sp++;
+ n--;
+ }
+
+ if( 0 == n ) return 0;
+
+ std::vector<uint8_t> dest;
+ {
+ bool escaped = false;
+
+ while( 0 < n ) {
+
+ n--;
+ uint8_t c = *sp++;
+
+ if( escaped ) {
+ switch( c ) {
+
+ case TFESC:
+ dest.push_back( FESC );
+ break;
+
+ case TFEND:
+ dest.push_back( FEND );
+ break;
+
+ default: // this is an error - ignore and continue
+ break;
+ }
+
+ escaped = false;
+
+ } else {
+
+ switch( c ) {
+ case FESC:
+ escaped = true;
+ break;
+
+ case FEND:
+ if( 0 != n ) {
+ SG_LOG(SG_IO, SG_WARN,
+ "KISS frame detected FEND before end of frame. Trailing data dropped." );
+ }
+ n = 0;
+ break;
+
+ default:
+ dest.push_back( c );
+ break;
+ }
+ }
+ }
+ }
+
+ memcpy( buf, dest.data(), dest.size() );
+ return dest.size();
+}
+
+
+class FGSTXETXWrapper : public FGProtocolWrapper {
+public:
+ virtual int wrap( size_t n, uint8_t * buf );
+ virtual int unwrap( size_t n, uint8_t * buf );
+
+ static const uint8_t STX;
+ static const uint8_t ETX;
+ static const uint8_t DLE;
+};
+
+const uint8_t FGSTXETXWrapper::STX = 0x02;
+const uint8_t FGSTXETXWrapper::ETX = 0x03;
+const uint8_t FGSTXETXWrapper::DLE = 0x00;
+
+int FGSTXETXWrapper::wrap( size_t n, uint8_t * buf )
+{
+ // stuff payload as
+ // <dle><stx>payload<dle><etx>
+ // if payload contains <dle>, stuff <dle> as <dle><dle>
+ std::vector<uint8_t> dest;
+ uint8_t *sp = buf;
+
+ dest.push_back(DLE);
+ dest.push_back(STX);
+
+ while( n > 0 ) {
+ n--;
+
+ if( DLE == *sp )
+ dest.push_back(DLE);
+
+ dest.push_back(*sp++);
+ }
+
+ dest.push_back(DLE);
+ dest.push_back(ETX);
+
+ memcpy( buf, dest.data(), dest.size() );
+ return dest.size();
+}
+
+int FGSTXETXWrapper::unwrap( size_t n, uint8_t * buf )
+{
+ return n;
+}
+
+FGGeneric::FGGeneric(vector<string> tokens) : exitOnError(false), initOk(false), wrapper(NULL)