protected override void Decode(IChannelHandlerContext context, IByteBuffer input, List <object> output)
{
try
{
switch (State)
{
case Socks5CommandRequestDecoderState.Init:
var version = input.ReadByte();
if (version != (byte)SocksVersion.Socks5)
{
throw new DecoderException(
"unsupported version: " + version + " (expected: " + SocksVersion.Socks5 + ')');
}
var type = Socks5CommandType.ValueOf(input.ReadByte());
input.SkipBytes(1); // RSV
var dstAddrType = Socks5AddressType.ValueOf(input.ReadByte());
var dstAddr = _addressDecoder.DecodeAddress(dstAddrType, input);
int dstPort = input.ReadUnsignedShort();
output.Add(new DefaultSocks5CommandRequest(type, dstAddrType, dstAddr, dstPort));
Checkpoint(Socks5CommandRequestDecoderState.Success);
break;
case Socks5CommandRequestDecoderState.Success:
{
var readableBytes = ActualReadableBytes;
if (readableBytes > 0)
{
output.Add(input.ReadRetainedSlice(readableBytes));
}
break;
}
case Socks5CommandRequestDecoderState.Failure:
{
input.SkipBytes(ActualReadableBytes);
break;
}
}
}
catch
(Exception e)
{
Fail(output, e);
}
}
public DefaultSocks5CommandRequest(
Socks5CommandType type,
Socks5AddressType dstAddrType,
string dstAddr,
int dstPort)
{
if (Equals(dstAddrType, Socks5AddressType.Pv4))
{
if (!IPAddress.TryParse(dstAddr, out _))
{
throw new ArgumentException("dstAddr: " + dstAddr + " (expected: a valid IPv4 address)");
}
}
else if (dstAddrType == Socks5AddressType.Domain)
{
dstAddr = Idn.GetAscii(dstAddr);
if (dstAddr.Length > 255)
{
throw new ArgumentException("dstAddr: " + dstAddr + " (expected: less than 256 chars)");
}
}
else if (dstAddrType == Socks5AddressType.Pv6)
{
if (!IPAddress.TryParse(dstAddr, out _))
{
throw new ArgumentException("dstAddr: " + dstAddr + " (expected: a valid IPv6 address");
}
}
if (dstPort < 0 || dstPort > 65535)
{
throw new ArgumentException("dstPort: " + dstPort + " (expected: 0~65535)");
}
Type = type;
DstAddrType = dstAddrType;
DstAddr = dstAddr;
DstPort = dstPort;
}
