base/process/process_handle.h

// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_PROCESS_PROCESS_HANDLE_H_
#define BASE_PROCESS_PROCESS_HANDLE_H_

#include "base/base_export.h"
#include "base/basictypes.h"
#include "base/files/file_path.h"
#include "build/build_config.h"

#include <sys/types.h>
#if defined(OS_WIN)
#include <windows.h>
#endif

namespace base {

// ProcessHandle is a platform specific type which represents the underlying OS
// handle to a process.
// ProcessId is a number which identifies the process in the OS.
#if defined(OS_WIN)
typedef HANDLE ProcessHandle;
typedef DWORD ProcessId;
typedef HANDLE UserTokenHandle;
const ProcessHandle kNullProcessHandle = NULL;
const ProcessId kNullProcessId = 0;
#elif defined(OS_POSIX)
// On POSIX, our ProcessHandle will just be the PID.
typedef pid_t ProcessHandle;
typedef pid_t ProcessId;
const ProcessHandle kNullProcessHandle = 0;
const ProcessId kNullProcessId = 0;
#endif  // defined(OS_WIN)

// Returns the id of the current process.
BASE_EXPORT ProcessId GetCurrentProcId();

// Returns the ProcessHandle of the current process.
BASE_EXPORT ProcessHandle GetCurrentProcessHandle();

// Converts a PID to a process handle. This handle must be closed by
// CloseProcessHandle when you are done with it. Returns true on success.
BASE_EXPORT bool OpenProcessHandle(ProcessId pid, ProcessHandle* handle);

// Converts a PID to a process handle. On Windows the handle is opened
// with more access rights and must only be used by trusted code.
// You have to close returned handle using CloseProcessHandle. Returns true
// on success.
// TODO(sanjeevr): Replace all calls to OpenPrivilegedProcessHandle with the
// more specific OpenProcessHandleWithAccess method and delete this.
BASE_EXPORT bool OpenPrivilegedProcessHandle(ProcessId pid,
                                             ProcessHandle* handle);

// Converts a PID to a process handle using the desired access flags. Use a
// combination of the kProcessAccess* flags defined above for |access_flags|.
BASE_EXPORT bool OpenProcessHandleWithAccess(ProcessId pid,
                                             uint32 access_flags,
                                             ProcessHandle* handle);

// Closes the process handle opened by OpenProcessHandle.
BASE_EXPORT void CloseProcessHandle(ProcessHandle process);

// Returns the unique ID for the specified process. This is functionally the
// same as Windows' GetProcessId(), but works on versions of Windows before
// Win XP SP1 as well.
BASE_EXPORT ProcessId GetProcId(ProcessHandle process);

#if defined(OS_WIN)
enum IntegrityLevel {
  INTEGRITY_UNKNOWN,
  LOW_INTEGRITY,
  MEDIUM_INTEGRITY,
  HIGH_INTEGRITY,
};
// Determine the integrity level of the specified process. Returns false
// if the system does not support integrity levels (pre-Vista) or in the case
// of an underlying system failure.
BASE_EXPORT bool GetProcessIntegrityLevel(ProcessHandle process,
                                          IntegrityLevel* level);
#endif

#if defined(OS_POSIX)
// Returns the path to the executable of the given process.
BASE_EXPORT FilePath GetProcessExecutablePath(ProcessHandle process);

// Returns the ID for the parent of the given process.
BASE_EXPORT ProcessId GetParentProcessId(ProcessHandle process);
#endif

}  // namespace base

#endif  // BASE_PROCESS_PROCESS_HANDLE_H_