Hi All,
I downloaded the example code for NamedPipeServerStream.RunAsClient from the MS docs:
https://docs.microsoft.com/en-us/dotnet/api/system.io.pipes.namedpipeserverstream.runasclient?view=net-5.0
I must be missing something. It hangs at pipeServer.WaitForConnection();
Can anyone clue me in?
Thanks!
using System;
using System.IO;
using System.IO.Pipes;
using System.Text;
using System.Threading;
// EXAMPLE from there :>
// https://docs.microsoft.com/en-us/dotnet/api/system.io.pipes.namedpipeserverstream.runasclient?view=net-5.0
public class PipeServer
{
private static int numThreads = 4;
public static void Main()
{
int i;
Thread[] servers = new Thread[numThreads];
Console.WriteLine("\n*** Named pipe server stream with impersonation example ***\n");
Console.WriteLine("Waiting for client connect...\n");
for (i = 0; i < numThreads; i++)
{
servers[i] = new Thread(ServerThread);
servers[i].Start();
}
//Thread.Sleep(250);
Thread.Sleep(2000);
Console.WriteLine("Client threads started for {0} threads.", numThreads);
while (i > 0)
{
for (int j = 0; j < numThreads; j++)
{
if (servers[j] != null)
{
//if (servers[j].Join(250))
if (servers[j].Join(3000))
{
Console.WriteLine("Server thread[{0}] finished.", servers[j].ManagedThreadId);
servers[j] = null;
i--; // decrement the thread watch count
}
else
Console.WriteLine("Client thread {0} running ...", servers[j].ManagedThreadId);
}
}
}
Console.WriteLine("\nServer threads exhausted, exiting.");
}
private static void ServerThread(object data)
{
NamedPipeServerStream
pipeServer = new NamedPipeServerStream
("testpipe", PipeDirection.InOut, numThreads);
int threadId = Thread.CurrentThread.ManagedThreadId;
Console.WriteLine("Client connecting on thread[{0}].", threadId);
// Wait for a client to connect
// THIS IS WHERE THE PROBLEM IS:
// A client never connects.
pipeServer.WaitForConnection();
Console.WriteLine("Client connected on thread[{0}].", threadId);
try
{
// Read the request from the client. Once the client has
// written to the pipe its security token will be available.
StreamString ss = new StreamString(pipeServer);
// Verify our identity to the connected client using a
// string that the client anticipates.
ss.WriteString("I am the one true server!");
string filename = ss.ReadString();
// Read in the contents of the file while impersonating the client.
ReadFileToStream fileReader = new ReadFileToStream(ss, filename);
// Display the name of the user we are impersonating.
Console.WriteLine
("Reading file: {0} on thread[{1}] as user: {2}.",
filename, threadId, pipeServer.GetImpersonationUserName());
pipeServer.RunAsClient(fileReader.Start);
}
// Catch the IOException that is raised if the pipe is broken
// or disconnected.
catch (IOException e)
{
Console.WriteLine("ERROR: {0}", e.Message);
}
pipeServer.Close();
}
}
// Defines the data protocol for reading and writing strings on our stream
public class StreamString
{
private Stream ioStream;
private UnicodeEncoding streamEncoding;
public StreamString(Stream ioStream)
{
this.ioStream = ioStream;
streamEncoding = new UnicodeEncoding();
}
public string ReadString()
{
int len = 0;
len = ioStream.ReadByte() * 256;
len += ioStream.ReadByte();
byte[] inBuffer = new byte[len];
ioStream.Read(inBuffer, 0, len);
return streamEncoding.GetString(inBuffer);
}
public int WriteString(string outString)
{
byte[] outBuffer = streamEncoding.GetBytes(outString);
int len = outBuffer.Length;
if (len > UInt16.MaxValue)
{
len = (int)UInt16.MaxValue;
}
ioStream.WriteByte((byte)(len / 256));
ioStream.WriteByte((byte)(len & 255));
ioStream.Write(outBuffer, 0, len);
ioStream.Flush();
return outBuffer.Length + 2;
}
}
// Contains the method executed in the context of the impersonated user
public class ReadFileToStream
{
private string fn;
private StreamString ss;
public ReadFileToStream(StreamString str, string filename)
{
fn = filename;
ss = str;
}
public void Start()
{
string contents = File.ReadAllText(fn);
ss.WriteString(contents);
}
}
THANKS!
Wally
