Question

我正在尝试在Android上制作端口扫描程序而且我有点卡住了。我想看看路由器/默认网关上是否打开了端口，但似乎没有任何工作。我尝试使用是可以访问的，但我觉得这可能是错误的。

import java.net.InetAddress;
import java.net.UnknownHostException;

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.content.IntentFilter; 
import android.net.DhcpInfo; 
import android.net.wifi.WifiInfo; 
import android.net.wifi.WifiManager; 
import android.os.Bundle; 
import android.widget.TextView;

public class portscan extends Activity {

String targetHost;
public int startPort = 1; //(for uses in later programming)
public int endPort = 1000;
private Intent scanIntent;
InetAddress targetAddress;
String targetHostName;
WifiManager networkd;
DhcpInfo details;
public String   gateway;
TextView GW;


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
     try {
    setContentView(R.layout.port);
    GW = (TextView)findViewById(R.id.gateway);
    networkd = (WifiManager) getSystemService(Context.WIFI_SERVICE);
    details = networkd.getDhcpInfo();
    String test = intToIp(details.gateway);

    gateway = "Default Gateway: "+String.valueOf(details.gateway);
    boolean isAvailable = false;

        isAvailable = InetAddress.getByName(test).isReachable(80); //trying to see if port open
        if (isAvailable == true) {
             GW.setText("port 21 is up"); 

        }
    } catch (Exception e) {

    }


}

public String intToIp(int i) { //this converts the DHCP information (default gateway) into a readable network address

       return ( i & 0xFF)+ "." +
                ((i >> 8 ) & 0xFF) + "." +
                ((i >> 16 ) & 0xFF)+ "." +
                ((i >> 24 ) & 0xFF );
    }

Answer 1

不要使用isReachable，它不适用于端口扫描（并且对其他任何东西都不可靠，真的）。

对于端口扫描，您使用sockets。伪示例：

   for (int port = 0; port <= 9999; port++) 
   {
        try 
        {
            // Try to create the Socket on the given port.
            Socket socket = new Socket(localhost, port);

            // If we arrive here, the port is open! 
            GW.setText( GW.getText() + String.Format( "Port %d is open. Cheers!\n", port ));

            // Don't forget to close it
            socket.close();
        } 
        catch (IOException e) 
        {
            // Failed to open the port. Booh.
        }
    }

Answer 2

使用下面的代码可以添加超时。

try {
    Socket socket = new Socket();
    SocketAddress address = new InetSocketAddress(ip, port);
    socket.connect(address, TIMEOUT);
    //OPEN
    socket.close();
} catch (UnknownHostException e) {
    //WRONG ADDRESS
} catch (SocketTimeoutException e) {
    //TIMEOUT
} catch (IOException e) {
    //CLOSED
}

Android端口扫描仪

2 个答案: