因?yàn)?Go 原生支持高并發(fā)，所以可以用高效的協(xié)程goroutine 來(lái)實(shí)現(xiàn)一個(gè)TCP 端口掃描器。

這里通過(guò)互斥鎖來(lái)解決數(shù)據(jù)競(jìng)爭(zhēng)問(wèn)題，使用WaitGroup來(lái)解決協(xié)程同步的問(wèn)題，TCPScanner代碼如下：

package main

import (
    "fmt"
    "log"
    "net"
    "sync"
    "time"
)

func main() {
    var wg sync.WaitGroup
    var mutex sync.Mutex
    ports := make([]int, 0)
    for i := 80; i <= 50000; i++ {
        wg.Add(1)
        go func(port int) {
            defer wg.Done()
            conn, err := net.DialTimeout("tcp", fmt.Sprintf("127.0.0.1:%d", port), time.Second)
            if err != nil {
                log.Printf("Error:%v.Port:[%d]\n", err, port)
            } else {
                conn.Close()
                log.Printf("Connection successful.Port:[%d]\n", port)
                mutex.Lock()
                ports = append(ports, port)
                mutex.Unlock()
            }
        }(i)
    }
    wg.Wait()
    fmt.Printf("Opened ports:%v", ports)
}

在筆者的Windows 10筆記本上面測(cè)試80~500有哪些端口是開(kāi)放的，程序輸出ports有：

TCPScanner 輸出結(jié)果

Windows 命令行結(jié)果