Go语言黑帽子学习2

代码清单2-3完整的端口扫描器

package main

import (

"fmt"

"net"

)

func main() {

for i := 1; i <= 1024; i++ {

address := fmt.Sprintf("172.23.190.244:%d", i)

conn, err := net.Dial("tcp", address)

if err != nil {

continue

}

conn.Close()

fmt.Printf("%d open\n", i)

}

}

代码清单2-7基本的worker池

package main

import (

    "fmt"

    "sync"

)

func worker(ports chan int, wg *sync.WaitGroup) {

    for p := range ports {

        fmt.Println(p)

        wg.Done()

    }

}

func main() {

    ports := make(chan int, 100)

    var wg sync.WaitGroup

    for i := 0; i < cap(ports); i++ {

        go worker(ports, &wg)

    }

    for i := 0; i <= 1024; i++ {

        wg.Add(1)

        ports <- i

    }

    wg.Wait()

    close(ports)

}

代码清单2-8使用多通道进行端口扫描

package main

import (

    "fmt"

    "net"

    "sort"

)

func worker(ports, result chan int) {

    for p := range ports {

        address := fmt.Sprintf("172.23.190.244:%d", p)

        conn, err := net.Dial("tcp", address)

        if err != nil {

            result <- 0

            continue

        }

        conn.Close()

        result <- 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 := 0; i <= 1024; i++ {

            ports <- i

        }

    }()

    for i := 0; i < 1024; 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)

    }

}