Porady: stosowanie nazwanych potoków do sieciowej komunikacji międzyprocesowej

Artykuł
12/30/2023

Nazwane potoki zapewniają komunikację międzyprocesorową pomiędzy serwerem potoku i jednym lub kilkoma klientami potoku. Oferują one więcej funkcji niż potoki anonimowe, które zapewniają komunikację międzyprocesorową na komputerze lokalnym. Nazwane potoki obsługują komunikację pełnodupleksową przez sieć i wiele instancji serwera, komunikację opartą na komunikatach i personifikację klienta, co pozwala łączyć procesy z ich własnymi zestawami uprawnień na serwerach zdalnych.

Ważne

Platforma .NET w systemie Linux używa gniazd domeny systemu Unix (UDS) do implementacji tych interfejsów API.

Aby zaimplementować nazwane potoki, należy użyć klas NamedPipeServerStream i NamedPipeClientStream.

Przykład 1

W poniższym przykładzie pokazano jak utworzyć nazwany potok używając klasy NamedPipeServerStream. W tym przykładzie proces serwera tworzy cztery wątki. Każdy wątek może zaakceptować połączenie klienta. Następnie połączony proces klienta dostarcza do serwera nazwę pliku. Jeśli klient ma wystarczające uprawnienia, proces serwera otwiera plik i wysyła jego zawartość z powrotem do klienta.

#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();
}

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);
    }
}

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(vbCrLf + "*** Named pipe server stream with impersonation example ***" + vbCrLf)
        Console.WriteLine("Waiting for client connect..." + vbCrLf)
        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) Then
                        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(vbCrLf + "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(CType(inBuffer, Byte()))
    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

Przykład 2

W poniższym przykładzie pokazano proces klienta, który korzysta z klasy NamedPipeClientStream. Klient łączy się z procesem serwera i wysyła nazwę pliku do serwera. W przykładzie użyto personifikacji, więc tożsamość, która uruchamia aplikację klienta, musi mieć uprawnienia dostępu do tego pliku. Serwer wysyła następnie zawartość pliku z powrotem do klienta. Zawartość pliku jest następnie wyświetlana w konsoli.

using System;
using System.Diagnostics;
using System.IO;
using System.IO.Pipes;
using System.Security.Principal;
using System.Text;
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")
            {
                var pipeClient =
                    new NamedPipeClientStream(".", "testpipe",
                        PipeDirection.InOut, PipeOptions.None,
                        TokenImpersonationLevel.Impersonation);

                Console.WriteLine("Connecting to server...\n");
                pipeClient.Connect();

                var 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()
    {
        string currentProcessName = Environment.CommandLine;

        // Remove extra characters when launched from Visual Studio
        currentProcessName = currentProcessName.Trim('"', ' ');

        currentProcessName = Path.ChangeExtension(currentProcessName, ".exe");
        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);

        int i;
        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[{plist[j]?.Id}] has exited.");
                        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();
        var 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;
    }
}

Imports System.Diagnostics
Imports System.IO
Imports System.IO.Pipes
Imports System.Security.Principal
Imports System.Text
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..." + vbCrLf)
                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(vbCrLf + "*** Named pipe client stream with impersonation example ***" + vbCrLf)
            StartClients()
        End If
    End Sub

    ' Helper function to create pipe client processes
    Private Shared Sub StartClients()
        Dim currentProcessName As String = Environment.CommandLine
        Dim plist(numClients - 1) As Process

        Console.WriteLine("Spawning client processes..." + vbCrLf)

        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)

        ' Change extension for .NET Core "dotnet run" returns the DLL, not the host exe.
        currentProcessName = Path.ChangeExtension(currentProcessName, ".exe")

        Dim i As Integer
        For i = 0 To numClients - 1
            ' Start 'this' program but spawn a named pipe client.
            plist(i) = Process.Start(currentProcessName, "spawnclient")
        Next
        While i > 0
            For j As Integer = 0 To numClients - 1
                If plist(j) IsNot Nothing Then
                    If plist(j).HasExited Then
                        Console.WriteLine($"Client process[{plist(j).Id}] has exited.")
                        plist(j) = Nothing
                        i -= 1    ' decrement the process watch count
                    Else
                        Thread.Sleep(250)
                    End If
                End If
            Next
        End While
        Console.WriteLine(vbCrLf + "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(CType(inBuffer, Byte()))
    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

Niezawodne programowanie

Procesy klienta i serwera w tym przykładzie są przeznaczone do uruchomienia na tym samym komputerze, więc nazwa serwera dostarczona do obiektu NamedPipeClientStream to ".". Jeśli procesy klienta i serwera znajdują się na oddzielnych komputerach, "." zostanie zamienione na nazwę sieciową komputera, który uruchamia proces serwera.

Udostępnij za pośrednictwem

Porady: stosowanie nazwanych potoków do sieciowej komunikacji międzyprocesowej

Przykład 1

Przykład 2

Niezawodne programowanie

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Dodatkowe zasoby