go hack（一）端口扫描

法一

package main

import (
    "fmt"
    "net"
)

func main() {
    var datas []int // 用来保存扫描到的port
    var ports chan int = make(chan int)
    var done chan int = make(chan int)

    // 创建消费者
    for i := 0; i < 10; i++ {
        go func() {
            for {
                port, ok := <-ports
                if !ok {
                    break
                }
                add := fmt.Sprintf("scanme.namp.com:%d", port)
                _, err := net.Dial("tcp", add)
                if err != nil {
                    //log.Fatalln(err)
                    fmt.Println(err)
                } else {
                    datas = append(datas, port)
                }

            }
            done <- 1
        }()
    }

    for i := 1; i < 100; i++ {
        ports <- i
    }

    for v := range done {
        fmt.Println(v)
    }
    fmt.Println(datas)

}

法二

package main

import (
    "fmt"
    "net"
    "sort"
)

func worker(ports, results chan int) {
    for p := range ports {
        address := fmt.Sprintf("192.168.1.19:%d", p)
        conn, err := net.Dial("tcp", address)
        if err != nil {
            results <- 0
            continue
        }
        conn.Close()
        results <- p
    }
}

func main() {
    ports := make(chan int, 100)
    results := make(chan int)
    var openports []int

    for i := 0; i < cap(ports); i++ {
        go worker(ports, results)
    }

    go func() {
        for i := 1; i <= 65535; i++ {
            ports <- i
        }
    }()

    for i := 0; i < 65535; i++ {
        port := <-results
        if port != 0 {
            openports = append(openports, port)
        }
    }

    close(ports)
    close(results)
    sort.Ints(openports)
    for _, port := range openports {
        fmt.Printf("%d open\n", port)
    }
}