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//
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
//
#include <windows.h>
#include <stdio.h>
#include <wchar.h>
#include <assert.h>
#include "twowaypipe.h"
#define _ASSERTE assert
// This file contains implementation of a simple IPC mechanism - bidirectional named pipe.
// It is implemented on top of two one-directional names pipes (fifos on UNIX)
// Creates a server side of the pipe.
// Id is used to create pipes names and uniquely identify the pipe on the machine.
// true - success, false - failure (use GetLastError() for more details)
bool TwoWayPipe::CreateServer(DWORD id)
{
_ASSERTE(m_state == NotInitialized);
if (m_state != NotInitialized)
return false;
m_inboundPipe = CreateOneWayPipe(id, true);
if (m_inboundPipe == INVALID_HANDLE_VALUE)
{
return false;
}
m_outboundPipe = CreateOneWayPipe(id, false);
if (m_outboundPipe == INVALID_HANDLE_VALUE)
{
CloseHandle(m_inboundPipe);
m_inboundPipe = INVALID_HANDLE_VALUE;
return false;
}
m_state = Created;
return true;
}
// Connects to a previously opened server side of the pipe.
// Id is used to locate the pipe on the machine.
// true - success, false - failure (use GetLastError() for more details)
bool TwoWayPipe::Connect(DWORD id)
{
_ASSERTE(m_state == NotInitialized);
if (m_state != NotInitialized)
return false;
m_inboundPipe = OpenOneWayPipe(id, true);
if (m_inboundPipe == INVALID_HANDLE_VALUE)
{
return false;
}
m_outboundPipe = OpenOneWayPipe(id, false);
if (m_outboundPipe == INVALID_HANDLE_VALUE)
{
CloseHandle(m_inboundPipe);
m_inboundPipe = INVALID_HANDLE_VALUE;
return false;
}
m_state = ClientConnected;
return true;
}
// Waits for incoming client connections, assumes GetState() == Created
// true - success, false - failure (use GetLastError() for more details)
bool TwoWayPipe::WaitForConnection()
{
_ASSERTE(m_state == Created);
if (m_state != Created)
return false;
if (!ConnectNamedPipe(m_inboundPipe, NULL))
{
auto error = GetLastError();
if (error != ERROR_PIPE_CONNECTED)
return false;
}
if (!ConnectNamedPipe(m_outboundPipe, NULL))
{
auto error = GetLastError();
if (error != ERROR_PIPE_CONNECTED)
return false;
}
m_state = ServerConnected;
return true;
}
// Reads data from pipe. Returns number of bytes read or a negative number in case of an error.
// use GetLastError() for more details
int TwoWayPipe::Read(void *buffer, DWORD bufferSize)
{
_ASSERTE(m_state == ServerConnected || m_state == ClientConnected);
DWORD bytesRead;
BOOL ok = ReadFile(m_inboundPipe, buffer, bufferSize, &bytesRead, NULL);
if (ok)
{
return (int)bytesRead;
}
else
{
return -1;
}
}
// Writes data to pipe. Returns number of bytes written or a negative number in case of an error.
// use GetLastError() for more details
int TwoWayPipe::Write(const void *data, DWORD dataSize)
{
_ASSERTE(m_state == ServerConnected || m_state == ClientConnected);
DWORD bytesWritten;
BOOL ok = WriteFile(m_outboundPipe, data, dataSize, &bytesWritten, NULL);
if (ok)
{
FlushFileBuffers(m_outboundPipe);
return (int)bytesWritten;
}
else
{
return -1;
}
}
// Disconnect server or client side of the pipe.
// true - success, false - failure (use GetLastError() for more details)
bool TwoWayPipe::Disconnect()
{
if (m_state == ServerConnected)
{
DisconnectNamedPipe(m_outboundPipe);
DisconnectNamedPipe(m_inboundPipe);
CloseHandle(m_outboundPipe);
m_outboundPipe = INVALID_HANDLE_VALUE;
CloseHandle(m_inboundPipe);
m_inboundPipe = INVALID_HANDLE_VALUE;
m_state = NotInitialized;
return true;
}
else if (m_state == ClientConnected)
{
CloseHandle(m_outboundPipe);
m_outboundPipe = INVALID_HANDLE_VALUE;
CloseHandle(m_inboundPipe);
m_inboundPipe = INVALID_HANDLE_VALUE;
m_state = NotInitialized;
return true;
}
else
{
// nothign to do
return true;
}
}
#define PIPE_NAME_FORMAT_STR L"\\\\.\\pipe\\clr-debug-pipe-%d-%s"
// Connects to a one sided pipe previously created by CreateOneWayPipe.
// In order to successfully connect id and inbound flag should be the same.
HANDLE TwoWayPipe::OpenOneWayPipe(DWORD id, bool inbound)
{
WCHAR fullName[MAX_PATH];
// "in" and "out" are deliberately switched because we're opening a client side connection
int chars = swprintf_s(fullName, MAX_PATH, PIPE_NAME_FORMAT_STR, id, inbound ? L"out" : L"in");
_ASSERTE(chars > 0);
HANDLE handle = CreateFileW(
fullName,
inbound ? GENERIC_READ : GENERIC_WRITE,
0, // no sharing
NULL, // default security attributes
OPEN_EXISTING, // opens existing pipe
0, // default attributes
NULL); // no template file
return handle;
}
// Creates a one way pipe, id and inboud flag are used for naming.
// Created pipe is supposed to be connected to by OpenOneWayPipe.
HANDLE TwoWayPipe::CreateOneWayPipe(DWORD id, bool inbound)
{
WCHAR fullName[MAX_PATH];
int chars = swprintf_s(fullName, MAX_PATH, PIPE_NAME_FORMAT_STR, id, inbound ? L"in" : L"out");
_ASSERTE(chars > 0);
HANDLE handle = CreateNamedPipeW(fullName,
(inbound ? PIPE_ACCESS_INBOUND : PIPE_ACCESS_OUTBOUND) | FILE_FLAG_FIRST_PIPE_INSTANCE,
PIPE_TYPE_BYTE | PIPE_WAIT | PIPE_REJECT_REMOTE_CLIENTS,
1, // max number of instances
4000, //in buffer size
4000, //out buffer size
0, // default timeout
NULL); // default security
return handle;
}
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