protected override void Decode(IChannelHandlerContext context, IByteBuffer input, List <object> output)
{
try
{
switch (State)
{
case Socks4ClientDecoderState.Start:
int version = input.ReadByte();
if (version != 0)
{
throw new DecoderException("unsupported reply version: " + version + " (expected: 0)");
}
var status = Socks4CommandStatus.ValueOf(input.ReadByte());
int dstPort = input.ReadUnsignedShort();
var dstAddr = input.ReadInt().ToString();
output.Add(new DefaultSocks4CommandResponse(status, dstAddr, dstPort));
Checkpoint(Socks4ClientDecoderState.Success);
break;
case Socks4ClientDecoderState.Success:
{
if (ActualReadableBytes > 0)
{
output.Add(input.ReadRetainedSlice(ActualReadableBytes));
}
break;
}
case Socks4ClientDecoderState.Failure:
{
input.SkipBytes(ActualReadableBytes);
break;
}
}
}
catch (Exception e)
{
Fail(output, e);
}
}
/**
* Creates a new instance.
*
* @param status the status of the response
*/
/**
* Creates a new instance.
*
* @param status the status of the response
* @param dstAddr the {@code DSTIP} field of the response
* @param dstPort the {@code DSTPORT} field of the response
*/
public DefaultSocks4CommandResponse(Socks4CommandStatus status, string dstAddr = null, int dstPort = 0)
{
if (dstAddr != null)
{
if (!IPAddress.TryParse(dstAddr, out _))
{
throw new ArgumentException(
"dstAddr: " + dstAddr + " (expected: a valid IPv4 address)");
}
}
if (dstPort < 0 || dstPort > 65535)
{
throw new ArgumentException("dstPort: " + dstPort + " (expected: 0~65535)");
}
Status = status;
DstAddr = dstAddr;
DstPort = dstPort;
}