package main
import (
"net"
"fmt"
"os"
"runtime"
"time"
"strconv"
)
func loop(startport, endport int, inport chan int) {
for i := startport; i <= endport; i++{
inport <- i
}
}
func scanner(inport, outport, out chan int, ip net.IP, endport int){
for{
in := <- inport
//fmt.Println(in)
tcpaddr := &net.TCPAddr{ip,in}
conn, err := net.DialTCP("tcp", nil, tcpaddr)
if err != nil {
outport <- 0
}else{
outport <- in
}
conn.Close()
if in == endport{
out <- in
}
}
}
func main() {
starttime := time.Now().Unix()
runtime.GOMAXPROCS(4)
inport := make(chan int)
outport := make(chan int)
out := make(chan int)
collect := []int{}
if len(os.Args) != 4 {
fmt.Println("Usage: scanner.exe IP startport endport")
fmt.Println("Endport must be larger than startport")
os.Exit(0)
}
ip := net.ParseIP(os.Args[1])
if(os.Args[3] < os.Args[2]) {
fmt.Println("Usage: scanner IP startport endport")
fmt.Println("Endport must be larger than startport")
os.Exit(0)
}
startport, _:= strconv.Atoi(os.Args[2])
endport, _ := strconv.Atoi(os.Args[3])
go loop(startport, endport, inport)
for{
select {
case <-out:
fmt.Println(collect)
endtime := time.Now().Unix()
fmt.Println("The scan process has spent ",endtime-starttime,"second")
os.Exit(0)
default:
go scanner(inport, outport, out, ip, endport)
port := <- outport
if port != 0{
collect = append(collect, port)
}
}
}
}