Code2.Net.TcpTarpit

Tarpit services to slowly send data to incoming tcp connections.

Service Options

• string? ListenAddress, listener ip address
• string? Ports, comma seperated list of ports and port ranges
• bool UseIPv4Only, defaults to both ipv4 and ipv6, set to true for ipv4 only
• int WriteIntervalInMs, data send interval
• int WriteSize, the amount of bytes to send per interval
• int UpdateIntervalInSeconds, ConnectionsUpdated event interval
• int TimeoutInSeconds, connection timout
• string? ResponseFile (optional), filepath to a file containing the response data
• string? ResponseText (optional), response data

Example

using Code2.Net.TcpTarpit;
using System.Text;

var options = new TarpitServiceOptions
{
	ListenAddress = "192.168.2.23",
	Ports = "10-99",
	UseIPv4Only = true,
	WriteIntervalInMs = 200,
	WriteSize = 6,
	UpdateIntervalInSeconds = 3,
	TimeoutInSeconds = 600,
	//ResponseFile = null
	ResponseText = "0123456789"
};

var service = new TarpitService(options);
service.Start();
service.ConnectionsUpdated += (sender, args) =>
{
	string[] lines = args.Connections.Select(x => $"{x.RemoteEndPoint}\t{x.BytesSent}\t{Encoding.UTF8.GetString(x.Buffer)}").ToArray();
	foreach (var line in lines)
	{
		Console.WriteLine(line);
	}
};
Console.WriteLine("Service started with listeners {0}", service.ListenersCount);

Console.ReadKey();
service.Stop();

Console.WriteLine("Service stopped.");

The above code starts TarpitService listening on 90 endpoints from 192.168.2.23:10 till 192.168.2.23:90. Any incoming connections within the range will be accepted and added to a list of active connections. Every interval the active connections will sent the writesize in bytes from the responsetext option. The connection will be marked completed when a send data operation fails, or the timeout of 10 minutes exceeds. When marked completed after the next ConnectionsUpdated event it gets removed from the active connections list.

Program output:

Service started with listeners 90
[::ffff:192.168.2.23]:53728      24      890123
[::ffff:192.168.2.23]:53729      24      890123
[::ffff:192.168.2.23]:53729      54      890123
[::ffff:192.168.2.23]:53730      18      234567
[::ffff:192.168.2.23]:53730      54      890123
[::ffff:192.168.2.23]:53730      84      890123
Service stopped.

UseIPv4Only=true

Service started with listeners 90
192.168.2.23:53565       6       012345
192.168.2.23:53566       6       012345
192.168.2.23:53565       24      890123
192.168.2.23:53566       42      678901
192.168.2.23:53566       54      890123
Service stopped.

Remarks

Each connection has a unique id.
ConnectionsUpdated event timing vary when UpdateIntervalInSeconds is not a multiple of WriteIntervalInMs.
When the service stops it will complete active connections and send a last ConnectionsUpdated event.
If the data sent total bytes exceeds the data defined, it starts from the front (see InfiniteReader)