private Error ParseError(TftpStreamReader reader)
{
ushort errorCode = reader.ReadUInt16();
String message = ParseNullTerminatedString(reader);
return(new Error(errorCode, message));
}
private Data ParseData(TftpStreamReader reader)
{
ushort blockNumber = reader.ReadUInt16();
byte[] data = reader.ReadBytes(10000);
return(new Data(blockNumber, data));
}
private ITftpCommand ParseInternal(byte[] message)
{
TftpStreamReader reader = new TftpStreamReader(new MemoryStream(message));
ushort opcode = reader.ReadUInt16();
switch (opcode)
{
case ReadRequest.OpCode:
return(ParseReadRequest(reader));
case WriteRequest.OpCode:
return(ParseWriteRequest(reader));
case Data.OpCode:
return(ParseData(reader));
case Acknowledgement.OpCode:
return(ParseAcknowledgement(reader));
case Error.OpCode:
return(ParseError(reader));
case OptionAcknowledgement.OpCode:
return(ParseOptionAcknowledgement(reader));
default:
throw new TftpParserException("Invalid opcode");
}
}
private List <TransferOption> ParseTransferOptions(TftpStreamReader reader)
{
List <TransferOption> options = new List <TransferOption>();
while (true)
{
String name;
try
{
name = ParseNullTerminatedString(reader);
}
catch (IOException)
{
name = "";
}
if (name.Length == 0)
{
break;
}
string value = ParseNullTerminatedString(reader);
options.Add(new TransferOption(name, value));
}
return(options);
}
private WriteRequest ParseWriteRequest(TftpStreamReader reader)
{
String filename = ParseNullTerminatedString(reader);
TftpTransferMode mode = ParseModeType(ParseNullTerminatedString(reader));
IEnumerable <TransferOption> options = ParseTransferOptions(reader);
return(new WriteRequest(filename, mode, options));
}
private String ParseNullTerminatedString(TftpStreamReader reader)
{
byte b;
StringBuilder str = new StringBuilder();
while ((b = reader.ReadByte()) > 0)
{
str.Append((char)b);
}
return(str.ToString());
}
private Acknowledgement ParseAcknowledgement(TftpStreamReader reader)
{
ushort blockNumber = reader.ReadUInt16();
return(new Acknowledgement(blockNumber));
}
private OptionAcknowledgement ParseOptionAcknowledgement(TftpStreamReader reader)
{
IEnumerable <TransferOption> options = ParseTransferOptions(reader);
return(new OptionAcknowledgement(options));
}
