C# 使用 plink (putty) 处理输出重定向

Question

这个让我发疯...我想编写一个简单的 C# 应用程序（带有 GUI），通过 SSH 登录到我们的思科无线局域网控制器（短 WLC）并创建访客用户。如果不是 Cisco 出于某种原因决定不允许非交互式登录，这对于 SSH.NET 将非常容易——这意味着您不能传递用户名和密码，但必须在控制台中输入。更糟糕的是：他们在实际用户提示之前放置了一个额外的（非功能性）用户提示。上帝...

无论如何，我使用 plink.exe 解决了这个问题，它工作得很好，但是我想检查终端输出，以便确定某些命令是否正确执行。我也想使用输出登录，因为提示看起来有点慢，我不能依赖恒定的时间。

我找到了一些关于输出重定向的文章（例如Process.start: how to get the output?），但它只是不起作用。我只能在 plink.exe 关闭时收集输出，但我需要在 plink 仍在运行的情况下实时读取输出。

到目前为止，这是我的代码：

namespace WIFI
{
  public class Program
  {
    private static readonly ILog log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);

        Application.Run(new myForm());
    }

    public static String ProcessInput(string user)
    {
        GlobalVar.hasError = false;
        GlobalVar.status = "";

        if (user.Length < 5 || user.Length > 10)
        {
            GlobalVar.status = "Username ungültig";
            GlobalVar.hasError = true;
        }
        else
        {
            WLCconnection WLC = new WLCconnection();
            WLC.ConnectWLC();

            if (!GlobalVar.hasError) WLC.UserExists(user);

            if (!GlobalVar.hasError) WLC.CreateUser(user);

            WLC.CloseWLC();
        }

        return GlobalVar.status;
    }
  }

  public static class GlobalVar
  {
    public static Boolean hasError;
    public static String status;
  }

  public class WLCconnection
  {
    Process terminal = new Process();
    StringBuilder terminalOutput = new StringBuilder();

    Boolean telnet = Convert.ToBoolean(System.Configuration.ConfigurationManager.AppSettings["telnet"]);
    String WLChostname = System.Configuration.ConfigurationManager.AppSettings["WLChostname"];
    String WLCusername = System.Configuration.ConfigurationManager.AppSettings["WLCusername"];
    String WLCpassword = System.Configuration.ConfigurationManager.AppSettings["WLCpassword"];

    public void ConnectWLC()
    {
        terminal.StartInfo.FileName = @System.Configuration.ConfigurationManager.AppSettings["plinkpath"];
        terminal.StartInfo.UseShellExecute = false;
        terminal.StartInfo.RedirectStandardInput = true;
        terminal.StartInfo.RedirectStandardOutput = true;
        terminal.StartInfo.RedirectStandardError = true;
        terminal.StartInfo.CreateNoWindow = true;

        if (telnet) terminal.StartInfo.Arguments = "-telnet " + WLChostname;
        else terminal.StartInfo.Arguments = "-ssh " + WLChostname;

        terminal.OutputDataReceived += (s, e) => terminalOutput.Append(e.Data);
        //terminal.OutputDataReceived += new DataReceivedEventHandler(OutputHandler);
        terminal.ErrorDataReceived += (s, e) => terminalOutput.Append(e.Data);
        //terminal.ErrorDataReceived += new DataReceivedEventHandler(OutputHandler);

        terminal.Start();
        terminal.BeginOutputReadLine();
        terminal.BeginErrorReadLine();

        int runs = 0;
        if (!telnet)
        {
            while (!terminalOutput.ToString().Contains("login as:") && !GlobalVar.hasError)
            {
                Thread.Sleep(500);
                if (runs < 20) runs++;
                else GlobalVar.hasError = true;
            }
            terminal.StandardInput.Write("workaroundSSHproblem\n");
        }

        runs = 0;
        while (!terminalOutput.ToString().Contains("User:") && !GlobalVar.hasError)
        {
            Thread.Sleep(500);
            if (runs < 20) runs++;
            else GlobalVar.hasError = true;
        }
        terminal.StandardInput.Write(WLCusername + "\n");

        runs = 0;
        while (!terminalOutput.ToString().Contains("Password:") && !GlobalVar.hasError)
        {
            Thread.Sleep(500);
            if (runs < 20) runs++;
            else GlobalVar.hasError = true;
        }
        terminal.StandardInput.Write(WLCpassword + "\n");
    }

    public void CloseWLC()
    {
        terminal.StandardInput.WriteLine("logout");
        terminal.WaitForExit();
        terminal.CancelOutputRead();
        terminal.Close();
        terminal.Dispose();
    }

    public Boolean UserExists(String user)
    {
        int runs = 0;
        while (!terminalOutput.ToString().Contains("(Cisco Controller) >") && !GlobalVar.hasError)
        {
            Thread.Sleep(500);
            if (runs < 20) runs++;
            else GlobalVar.hasError = true;
        }
        terminal.StandardInput.Write("show netuser detail " + user);

        if (!terminalOutput.ToString().Contains("blabla"))
        {
            GlobalVar.status = "User " + user + " bereits aktiviert";
            GlobalVar.hasError = true;
        }

        return GlobalVar.hasError;
    }

    public void CreateUser(String user)
    {
        int runs = 0;
        while (!terminalOutput.ToString().Contains("(Cisco Controller) >") && !GlobalVar.hasError)
        {
            Thread.Sleep(500);
            if (runs < 20) runs++;
            else GlobalVar.hasError = true;
        }
        terminal.StandardInput.Write("config netuser add " + user + " " + System.Configuration.ConfigurationManager.AppSettings["guestpassword"] + " wlan 3 userType guest lifetime 86400");

        if (!GlobalVar.hasError)
        {
            if (UserExists(user))
            {
                GlobalVar.status = "";
                GlobalVar.hasError = false;
            }
            else
            {
                GlobalVar.status = "User " + user + " konnte nicht aktiviert werden";
                GlobalVar.hasError = true;
            }

        }
    }

    protected void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine)
    {
        terminalOutput.Append(outLine.Data);
    }
  }
}

非常感谢您的帮助！

Answer 1

对谁有帮助：我再次使用 SSH.NET 解决了这个问题，但这次不是使用内置函数登录，而是结合使用 ShellStream 手动处理输入和输出。到目前为止工作得很好。