Gewusst wie: Verwenden von benannten Pipes zur Kommunikation zwischen Prozessen über ein Netzwerk
Benannte Pipes bieten mehr Funktionen als anonyme Pipes. Diese Funktionen umfassen Vollduplexkommunikation über ein Netzwerk und mehrere Serverinstanzen, meldungsbasierte Kommunikation und Clientidentitätswechsel, die verbindenden Prozessen die Verwendung ihrer eigenen Berechtigungen auf Remoteservern ermöglichen.
Beispiel
Das folgende Beispiel zeigt, wie eine benannte Pipe mit der NamedPipeServerStream-Klasse erstellt wird. In diesem Beispiel erstellt der Serverprozess vier Threads. Jeder Thread kann eine Clientverbindung akzeptieren. Der verbundene Clientprozess sendet daraufhin einen Dateinamen an den Server. Wenn der Client über ausreichende Berechtigungen verfügt, öffnet der Serverprozess die Datei und sendet ihren Inhalt an den Client zurück.
Imports System
Imports System.IO
Imports System.IO.Pipes
Imports System.Text
Imports System.Threading
Public Class PipeServer
Private Shared numThreads As Integer = 4
Public Shared Sub Main()
Dim i As Integer
Dim servers(numThreads) As Thread
Console.WriteLine(vbNewLine + "*** Named pipe server stream with impersonation example ***" + vbNewLine)
Console.WriteLine("Waiting for client connect..." + vbNewLine)
For i = 0 To numThreads - 1
servers(i) = New Thread(AddressOf ServerThread)
servers(i).Start()
Next i
Thread.Sleep(250)
While i > 0
For j As Integer = 0 To numThreads - 1
If Not(servers(j) Is Nothing) Then
if servers(j).Join(250)
Console.WriteLine("Server thread[{0}] finished.", servers(j).ManagedThreadId)
servers(j) = Nothing
i -= 1 ' decrement the thread watch count
End If
End If
Next j
End While
Console.WriteLine(vbNewLine + "Server threads exhausted, exiting.")
End Sub
Private Shared Sub ServerThread(data As Object)
Dim pipeServer As New _
NamedPipeServerStream("testpipe", PipeDirection.InOut, numThreads)
Dim threadId As Integer = Thread.CurrentThread.ManagedThreadId
' Wait for a client to connect
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.
Dim ss As 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!")
Dim filename As String = ss.ReadString()
' Read in the contents of the file while impersonating the client.
Dim fileReader As 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(AddressOf fileReader.Start)
' Catch the IOException that is raised if the pipe is broken
' or disconnected.
Catch e As IOException
Console.WriteLine("ERROR: {0}", e.Message)
End Try
pipeServer.Close()
End Sub
End Class
' Defines the data protocol for reading and writing strings on our stream
Public Class StreamString
Private ioStream As Stream
Private streamEncoding As UnicodeEncoding
Public Sub New(ioStream As Stream)
Me.ioStream = ioStream
streamEncoding = New UnicodeEncoding(False, False)
End Sub
Public Function ReadString() As String
Dim len As Integer = 0
len = CType(ioStream.ReadByte(), Integer) * 256
len += CType(ioStream.ReadByte(), Integer)
Dim inBuffer As Array = Array.CreateInstance(GetType(Byte), len)
ioStream.Read(inBuffer, 0, len)
Return streamEncoding.GetString(inBuffer)
End Function
Public Function WriteString(outString As String) As Integer
Dim outBuffer() As Byte = streamEncoding.GetBytes(outString)
Dim len As Integer = outBuffer.Length
If len > UInt16.MaxValue Then
len = CType(UInt16.MaxValue, Integer)
End If
ioStream.WriteByte(CType(len \ 256, Byte))
ioStream.WriteByte(CType(len And 255, Byte))
ioStream.Write(outBuffer, 0, outBuffer.Length)
ioStream.Flush()
Return outBuffer.Length + 2
End Function
End Class
' Contains the method executed in the context of the impersonated user
Public Class ReadFileToStream
Private fn As String
Private ss As StreamString
Public Sub New(str As StreamString, filename As String)
fn = filename
ss = str
End Sub
Public Sub Start()
Dim contents As String = File.ReadAllText(fn)
ss.WriteString(contents)
End Sub
End Class
using System;
using System.IO;
using System.IO.Pipes;
using System.Text;
using System.Threading;
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);
while (i > 0)
{
for (int j = 0; j < numThreads; j++)
{
if (servers[j] != null)
{
if (servers[j].Join(250))
{
Console.WriteLine("Server thread[{0}] finished.", servers[j].ManagedThreadId);
servers[j] = null;
i--; // decrement the thread watch count
}
}
}
}
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;
// Wait for a client to connect
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);
}
}
#using <System.Core.dll>
using namespace System;
using namespace System::IO;
using namespace System::IO::Pipes;
using namespace System::Text;
using namespace System::Threading;
// Defines the data protocol for reading and writing strings on our stream
public ref class StreamString
{
private:
Stream^ ioStream;
UnicodeEncoding^ streamEncoding;
public:
StreamString(Stream^ ioStream)
{
this->ioStream = ioStream;
streamEncoding = gcnew UnicodeEncoding();
}
String^ ReadString()
{
int len;
len = ioStream->ReadByte() * 256;
len += ioStream->ReadByte();
array<Byte>^ inBuffer = gcnew array<Byte>(len);
ioStream->Read(inBuffer, 0, len);
return streamEncoding->GetString(inBuffer);
}
int WriteString(String^ outString)
{
array<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 ref class ReadFileToStream
{
private:
String^ fn;
StreamString ^ss;
public:
ReadFileToStream(StreamString^ str, String^ filename)
{
fn = filename;
ss = str;
}
void Start()
{
String^ contents = File::ReadAllText(fn);
ss->WriteString(contents);
}
};
public ref class PipeServer
{
private:
static int numThreads = 4;
public:
static void Main()
{
int i;
array<Thread^>^ servers = gcnew array<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] = gcnew Thread(gcnew ThreadStart(&ServerThread));
servers[i]->Start();
}
Thread::Sleep(250);
while (i > 0)
{
for (int j = 0; j < numThreads; j++)
{
if (servers[j] != nullptr)
{
if (servers[j]->Join(250))
{
Console::WriteLine("Server thread[{0}] finished.", servers[j]->ManagedThreadId);
servers[j] = nullptr;
i--; // decrement the thread watch count
}
}
}
}
Console::WriteLine("\nServer threads exhausted, exiting.");
}
private:
static void ServerThread()
{
NamedPipeServerStream^ pipeServer =
gcnew NamedPipeServerStream("testpipe", PipeDirection::InOut, numThreads);
int threadId = Thread::CurrentThread->ManagedThreadId;
// Wait for a client to connect
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 = gcnew 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 = gcnew 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(gcnew PipeStreamImpersonationWorker(fileReader, &ReadFileToStream::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();
}
};
int main()
{
PipeServer::Main();
}
Das folgende Beispiel zeigt den Clientprozess, der die NamedPipeClientStream-Klasse verwendet. Der Client stellt eine Verbindung mit dem Serverprozess her und sendet einen Dateinamen an den Server. In diesem Beispiel wird ein Identitätswechsel verwendet, sodass die Identität, die die Clientanwendung ausführt, eine Berechtigung für den Zugriff auf die Datei benötigt. Anschließend sendet der Server den Inhalt der Datei an den Client zurück. Der Inhalt der Datei wird daraufhin auf der Konsole angezeigt.
Imports System
Imports System.IO
Imports System.IO.Pipes
Imports System.Text
Imports System.Security.Principal
Imports System.Diagnostics
Imports System.Threading
Public Class PipeClient
Private Shared numClients As Integer = 4
Public Shared Sub Main(Args() As String)
If Args.Length > 0 Then
If Args(0) = "spawnclient" Then
Dim pipeClient As New NamedPipeClientStream( _
".", "testpipe", _
PipeDirection.InOut, PipeOptions.None, _
TokenImpersonationLevel.Impersonation)
Console.WriteLine("Connecting to server..." + vbNewLine)
pipeClient.Connect()
Dim ss As New StreamString(pipeClient)
' Validate the server's signature string
If ss.ReadString() = "I am the one true server!" Then
' The client security token is sent with the first write.
' Send the name of the file whose contents are returned
' by the server.
ss.WriteString("c:\textfile.txt")
' Print the file to the screen.
Console.Write(ss.ReadString())
Else
Console.WriteLine("Server could not be verified.")
End If
pipeClient.Close()
' Give the client process some time to display results before exiting.
Thread.Sleep(4000)
End If
Else
Console.WriteLine(vbNewLine + "*** Named pipe client stream with impersonation example ***" + vbNewLine)
StartClients()
End If
End Sub
' Helper function to create pipe client processes
Private Shared Sub StartClients()
Dim i As Integer
Dim currentProcessName As String = Environment.CommandLine
Dim plist(numClients) As Process
Console.WriteLine("Spawning client processes..." + vbNewLine)
If (currentProcessName.Contains(Environment.CurrentDirectory)) Then
currentProcessName = currentProcessName.Replace(Environment.CurrentDirectory, String.Empty)
End If
' Remove extra characters when launched from Visual Studio
currentProcessName = currentProcessName.Replace("\", String.Empty)
currentProcessName = currentProcessName.Replace("""", String.Empty)
For i = 0 To numClients - 1
' Start 'this' program but spawn a named pipe client.
plist(i) = Process.Start(currentProcessName, "spawnclient")
Next i
While i > 0
For j As Integer = 0 To numClients - 1
If Not (plist(j) Is Nothing) Then
If plist(j).HasExited Then
Console.WriteLine("Client process[{0}] has exited.", _
plist(j).Id)
plist(j) = Nothing
i -= 1 ' decrement the process watch count
Else
Thread.Sleep(250)
End If
End If
Next j
End While
Console.WriteLine(vbNewLine + "Client processes finished, exiting.")
End Sub
End Class
' Defines the data protocol for reading and writing strings on our stream
Public Class StreamString
Private ioStream As Stream
Private streamEncoding As UnicodeEncoding
Public Sub New(ioStream As Stream)
Me.ioStream = ioStream
streamEncoding = New UnicodeEncoding(False, False)
End Sub
Public Function ReadString() As String
Dim len As Integer = 0
len = CType(ioStream.ReadByte(), Integer) * 256
len += CType(ioStream.ReadByte(), Integer)
Dim inBuffer As Array = Array.CreateInstance(GetType(Byte), len)
ioStream.Read(inBuffer, 0, len)
Return streamEncoding.GetString(inBuffer)
End Function
Public Function WriteString(outString As String) As Integer
Dim outBuffer() As Byte = streamEncoding.GetBytes(outString)
Dim len As Integer = outBuffer.Length
If len > UInt16.MaxValue Then
len = CType(UInt16.MaxValue, Integer)
End If
ioStream.WriteByte(CType(len \ 256, Byte))
ioStream.WriteByte(CType(len And 255, Byte))
ioStream.Write(outBuffer, 0, outBuffer.Length)
ioStream.Flush()
Return outBuffer.Length + 2
End Function
End Class
using System;
using System.IO;
using System.IO.Pipes;
using System.Text;
using System.Security.Principal;
using System.Diagnostics;
using System.Threading;
public class PipeClient
{
private static int numClients = 4;
public static void Main(string[] Args)
{
if (Args.Length > 0)
{
if (Args[0] == "spawnclient")
{
NamedPipeClientStream pipeClient =
new NamedPipeClientStream(".", "testpipe",
PipeDirection.InOut, PipeOptions.None,
TokenImpersonationLevel.Impersonation);
Console.WriteLine("Connecting to server...\n");
pipeClient.Connect();
StreamString ss = new StreamString(pipeClient);
// Validate the server's signature string
if (ss.ReadString() == "I am the one true server!")
{
// The client security token is sent with the first write.
// Send the name of the file whose contents are returned
// by the server.
ss.WriteString("c:\\textfile.txt");
// Print the file to the screen.
Console.Write(ss.ReadString());
}
else
{
Console.WriteLine("Server could not be verified.");
}
pipeClient.Close();
// Give the client process some time to display results before exiting.
Thread.Sleep(4000);
}
}
else
{
Console.WriteLine("\n*** Named pipe client stream with impersonation example ***\n");
StartClients();
}
}
// Helper function to create pipe client processes
private static void StartClients()
{
int i;
string currentProcessName = Environment.CommandLine;
Process[] plist = new Process[numClients];
Console.WriteLine("Spawning client processes...\n");
if (currentProcessName.Contains(Environment.CurrentDirectory))
{
currentProcessName = currentProcessName.Replace(Environment.CurrentDirectory, String.Empty);
}
// Remove extra characters when launched from Visual Studio
currentProcessName = currentProcessName.Replace("\\", String.Empty);
currentProcessName = currentProcessName.Replace("\"", String.Empty);
for (i = 0; i < numClients; i++)
{
// Start 'this' program but spawn a named pipe client.
plist[i] = Process.Start(currentProcessName, "spawnclient");
}
while (i > 0)
{
for (int j = 0; j < numClients; j++)
{
if (plist[j] != null)
{
if (plist[j].HasExited)
{
Console.WriteLine("Client process[{0}] has exited.",
plist[j].Id);
plist[j] = null;
i--; // decrement the process watch count
}
else
{
Thread.Sleep(250);
}
}
}
}
Console.WriteLine("\nClient processes finished, exiting.");
}
}
// 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;
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;
}
}
Robuste Programmierung
Der Client- und der Serverprozess in diesem Beispiel sind zur Ausführung auf dem gleichen Computer vorgesehen, sodass der Servername, der dem NamedPipeClientStream-Objekt bereitgestellt wird, "." lautet. Wenn der Client- und der Serverprozess auf verschiedenen Computern ausgeführt würden, würde "." durch den Netzwerknamen des Computers ersetzt, auf dem der Serverprozess ausgeführt wird.
Siehe auch
Aufgaben
Gewusst wie: Verwenden von anonymen Pipes zur Kommunikation zwischen lokalen Prozessen
Referenz
Konzepte
Änderungsprotokoll
Datum |
Versionsgeschichte |
Grund |
|---|---|---|
|
Oktober 2010 |
Das Beispiel wurde geändert, und Informationen zu Clientberechtigungen wurden hinzugefügt. |
Informationsergänzung. |