private ReadRequest ParseReadRequest(TftpStreamReader reader)
{
String filename = ParseNullTerminatedString(reader);
TftpTransferMode mode = ParseModeType(ParseNullTerminatedString(reader));
IEnumerable<TransferOption> options = ParseTransferOptions(reader);
return new ReadRequest(filename, mode, options);
}
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 Data ParseData(TftpStreamReader reader)
{
ushort blockNumber = reader.ReadUInt16();
byte[] data = reader.ReadBytes(10000);
return(new Data(blockNumber, data));
}
private Error ParseError(TftpStreamReader reader)
{
ushort errorCode = reader.ReadUInt16();
String message = ParseNullTerminatedString(reader);
return(new Error(errorCode, message));
}
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);
}