golang scan tcp ports

golang scan tcp ports

func TCPPortScan(ip string) (out string) {
    portIgnore := []int{22, 3389, 10050, 19100}
    cd := time.Second * 3
    goLimit := make(chan struct{}, 1000)
    var syncMap sync.Map
    var wg sync.WaitGroup
    wg.Add(65535)
    for port := 1; port <= 65535; port++ {
       if inIntSlice(portIgnore, port) {
          //白名单不测 计数器 -1
          wg.Done()
          continue
       }
       go func() {
          goLimit <- struct{}{}
          //200ms认为超时
          if portDialRaw(ip, strconv.Itoa(port), "tcp", cd) {
             syncMap.Store(port, port)
          }
          // 计数器 -1
          wg.Done()
          <-goLimit
       }()
    }
    //等待所有端口扫描完成 阻塞。计数器为 0 的时候，Wait 返回
    wg.Wait()
    close(goLimit)

    return syncMapSort(&syncMap)
}

func syncMapSort(syncMap *sync.Map) string {
    var intList []int
    // Range遍历所有sync.Map中的键值对
    syncMap.Range(func(k, v any) bool {
       if intValue, ok := k.(int); ok {
          intList = append(intList, intValue)
       }
       return true
    })
    sort.Ints(intList)
    var out string
    for _, value := range intList {
       out = out + " " + strconv.Itoa(value)
    }
    return strings.TrimLeft(out, " ")
}