一文详解Go如何实现端口扫描器

package mainimport (    "fmt"    "net"    "time"    "unsafe")func main() {    tcpScan("127.0.0.1", 1, 65535)}func tcpScan(ip string, portStart int, portEnd int) {    start := time.Now()    // 参数校验    isok := verifyParam(ip, portStart, portEnd)    if isok == false {        fmt.Printf("[Exit]
")    }    for i := portStart; i <= portEnd; i++ {        address := fmt.Sprintf("%s:%d", ip, i)        conn, err := net.Dial("tcp", address)        if err != nil {            fmt.Printf("[info] %s Close 
", address)            continue        }        conn.Close()        fmt.Printf("[info] %s Open 
", address)    }    cost := time.Since(start)    fmt.Printf("[tcpScan] cost %s second 
", cost)}func verifyParam(ip string, portStart int, portEnd int) bool {    netip := net.ParseIP(ip)    if netip == nil {        fmt.Println("[Error] ip type is must net.ip")        return false    }    fmt.Printf("[Info] ip=%s | ip type is: %T | ip size is: %d 
", netip, netip, unsafe.Sizeof(netip))    if portStart < 1 || portEnd > 65535 {        fmt.Println("[Error] port is must in the range of 1~65535")        return false    }    fmt.Printf("[Info] port start:%d end:%d 
", portStart, portEnd)    return true}

package mainimport (    "fmt"    "net"    "sync"    "time"    "unsafe")func main() {    tcpScanByGoroutine("127.0.0.1", 1, 65535)}func tcpScanByGoroutine(ip string, portStart int, portEnd int) {    start := time.Now()    // 参数校验    isok := verifyParam(ip, portStart, portEnd)    if isok == false {        fmt.Printf("[Exit]
")    }    var wg sync.WaitGroup    for i := portStart; i <= portEnd; i++ {        wg.Add(1)        go func(j int) {            defer wg.Done()            address := fmt.Sprintf("%s:%d", ip, j)            conn, err := net.Dial("tcp", address)            if err != nil {                fmt.Printf("[info] %s Close 
", address)                return            }            conn.Close()            fmt.Printf("[info] %s Open 
", address)        }(i)    }    wg.Wait()    cost := time.Since(start)    fmt.Printf("[tcpScanByGoroutine] cost %s second 
", cost)}func verifyParam(ip string, portStart int, portEnd int) bool {    netip := net.ParseIP(ip)    if netip == nil {        fmt.Println("[Error] ip type is must net.ip")        return false    }    fmt.Printf("[Info] ip=%s | ip type is: %T | ip size is: %d 
", netip, netip, unsafe.Sizeof(netip))    if portStart < 1 || portEnd > 65535 {        fmt.Println("[Error] port is must in the range of 1~65535")        return false    }    fmt.Printf("[Info] port start:%d end:%d 
", portStart, portEnd)    return true}

package mainimport (    "fmt"    "net"    "sync"    "time"    "unsafe")func main() {    tcpScanByGoroutineWithChannel("127.0.0.1", 1, 65535)}func handleWorker(ip string, ports chan int, wg *sync.WaitGroup) {    for p := range ports {        address := fmt.Sprintf("%s:%d", ip, p)        conn, err := net.Dial("tcp", address)        if err != nil {            fmt.Printf("[info] %s Close 
", address)            wg.Done()            continue        }        conn.Close()        fmt.Printf("[info] %s Open 
", address)        wg.Done()    }}func tcpScanByGoroutineWithChannel(ip string, portStart int, portEnd int) {    start := time.Now()    // 参数校验    isok := verifyParam(ip, portStart, portEnd)    if isok == false {        fmt.Printf("[Exit]
")    }    ports := make(chan int, 100)    var wg sync.WaitGroup    for i := 0; i < cap(ports); i++ {        go handleWorker(ip, ports, &wg)    }    for i := portStart; i <= portEnd; i++ {        wg.Add(1)        ports <- i    }    wg.Wait()    close(ports)    cost := time.Since(start)    fmt.Printf("[tcpScanByGoroutineWithChannel] cost %s second 
", cost)}func verifyParam(ip string, portStart int, portEnd int) bool {    netip := net.ParseIP(ip)    if netip == nil {        fmt.Println("[Error] ip type is must net.ip")        return false    }    fmt.Printf("[Info] ip=%s | ip type is: %T | ip size is: %d 
", netip, netip, unsafe.Sizeof(netip))    if portStart < 1 || portEnd > 65535 {        fmt.Println("[Error] port is must in the range of 1~65535")        return false    }    fmt.Printf("[Info] port start:%d end:%d 
", portStart, portEnd)    return true}

// packagepackage mainimport (    "fmt"    "net"    "sort"    "time"    "unsafe")func main() {    tcpScanByGoroutineWithChannelAndSort("127.0.0.1", 1, 65535)}// The function handles checking if ports are open or closed for a given IP address.func handleWorker(ip string, ports chan int, results chan int) {    for p := range ports {        address := fmt.Sprintf("%s:%d", ip, p)        conn, err := net.Dial("tcp", address)        if err != nil {            // fmt.Printf("[debug] ip %s Close 
", address)            results <- (-p)            continue        }        // fmt.Printf("[debug] ip %s Open 
", address)        conn.Close()        results <- p    }}func tcpScanByGoroutineWithChannelAndSort(ip string, portStart int, portEnd int) {    start := time.Now()    // 参数校验    isok := verifyParam(ip, portStart, portEnd)    if isok == false {        fmt.Printf("[Exit]
")    }    ports := make(chan int, 50)    results := make(chan int)    var openSlice []int    var closeSlice []int    // 任务生产者-分发任务 (新起一个 goroutinue ，进行分发数据)    go func(a int, b int) {        for i := a; i <= b; i++ {            ports <- i        }    }(portStart, portEnd)    // 任务消费者-处理任务  (每一个端口号都分配一个 goroutinue ，进行扫描)    // 结果生产者-每次得到结果 再写入 结果 chan 中    for i := 0; i < cap(ports); i++ {        go handleWorker(ip, ports, results)    }    // 结果消费者-等待收集结果 (main中的 goroutinue 不断从 chan 中阻塞式读取数据)    for i := portStart; i <= portEnd; i++ {        resPort := <-results        if resPort > 0 {            openSlice = append(openSlice, resPort)        } else {            closeSlice = append(closeSlice, -resPort)        }    }    // 关闭 chan    close(ports)    close(results)    // 排序    sort.Ints(openSlice)    sort.Ints(closeSlice)    // 输出    for _, p := range openSlice {        fmt.Printf("[info] %s:%-8d Open
", ip, p)    }    // for _, p := range closeSlice {    //     fmt.Printf("[info] %s:%-8d Close
", ip, p)    // }    cost := time.Since(start)    fmt.Printf("[tcpScanByGoroutineWithChannelAndSort] cost %s second 
", cost)}func verifyParam(ip string, portStart int, portEnd int) bool {    netip := net.ParseIP(ip)    if netip == nil {        fmt.Println("[Error] ip type is must net.ip")        return false    }    fmt.Printf("[Info] ip=%s | ip type is: %T | ip size is: %d 
", netip, netip, unsafe.Sizeof(netip))    if portStart < 1 || portEnd > 65535 {        fmt.Println("[Error] port is must in the range of 1~65535")        return false    }    fmt.Printf("[Info] port start:%d end:%d 
", portStart, portEnd)    return true}