jsctypes - 使用SHChangeNotifyRegister进行MEDIA/DRIVE事件的问题

Question

我正在尝试在Firefox中使用js-ctypes来接收USB媒体/驱动器通知,但是我遇到了一些问题,我不知道是不是因为我在Win32 API上经验不足或者在js-ctypes上很糟糕(或两者!)

我开始调整我在Alexandre Poirot博客上发现的一个例子:

• 博客条目
• 完整的JS来源

该示例使用js-ctypes创建"仅消息"窗口,然后与shell服务交互以便与Windows通知托盘进行通信.

这看起来很简单,所以在对RegisterDeviceNotification和SHChangeNotifyRegister的优点进行一些研究之后,我正在尝试调整那个(工作!)示例来注册设备更新SHChangeNotifyRegister.

代码驻留在bootstrapped(无重启)Firefox扩展(下面的代码)中.

该WindowProc工程的实施很好,如原始示例中所示.我的JavaScript回调记录了进来的Window消息(这个例子只是数字).

问题:

首先,似乎调用DestroyWindow崩溃shutdown()扩展了Firefox(几乎总是).是否有一些Windows消息我应该在"仅消息"窗口上处理以优雅地处理DestryWindow？

其次,虽然它从控制台输出(下面)看起来我从调用中得到有意义的值SHGetSpecialFolderLocation和SHChangeNotifyRegister(返回值不是错误,PIDLISTITEM指针是一些真实地址)我没有收到设备/驱动器消息在JavaScript回调中.

此外,我试图重现PIDLISTITEM结构无济于事(无法js-ctypes在调用中识别它们SHChangeNotifyRegister),在研究了一些其他非C++示例后,似乎大多数人只是使用long*- 我希望这是我的来源误解!

我已经通过Microsoft的类似C++示例项目验证了当SHChangeNotifyRegistration成功时我们收到消息本身并且我生成USB媒体事件(ny插入和移除USB闪存介质).

重现问题的最小代码如下:

---

install.rdf:

<?xml version="1.0"?>
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:em="http://www.mozilla.org/2004/em-rdf#">
  <Description about="urn:mozilla:install-manifest">
  <em:id>testwndproc@foo.com</em:id>
  <em:type>2</em:type>
  <em:name>TEST WNDPROC</em:name>
  <em:version>1.0</em:version>
  <em:bootstrap>true</em:bootstrap>
  <em:unpack>true</em:unpack>
  <em:description>Testing wndProc via JS-CTYPES on WIN32.</em:description>
  <em:creator>David</em:creator>

  <!-- Firefox Desktop -->
  <em:targetApplication>
    <Description>
    <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
    <em:minVersion>4.0.*</em:minVersion>
    <em:maxVersion>29.0.*</em:maxVersion>
    </Description>
  </em:targetApplication>
  </Description>
</RDF>

bootstrap.js:

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;

Components.utils.import("resource://gre/modules/ctypes.jsm");
let consoleService = Cc["@mozilla.org/consoleservice;1"]
                       .getService(Ci.nsIConsoleService);  
function LOG(msg) { 
    consoleService.logStringMessage("TEST-WNDPROC: "+msg); 
} 

var WindowProcType, DefWindowProc, RegisterClass, CreateWindowEx, 
    DestroyWindow, SHGetSpecialFolderLocation, WNDCLASS, wndclass, 
    messageWin, libs = {};

var windowProcJSCallback = function(hWnd, uMsg, wParam, lParam) {
  LOG("windowProc: "+JSON.stringify([uMsg, wParam, lParam]));
  //
  // TODO: decode uMsg, wParam, lParam to interpret 
  //       the incoming ShChangeNotifyEntry messages!
  //
  return DefWindowProc(hWnd, uMsg, wParam, lParam);
};

function startup(data, reason) {
  try {
    LOG("loading USER32.DLL ...");
    libs.user32 = ctypes.open("user32.dll");

    LOG("loading SHELL32.DLL ...");
    libs.shell32 = ctypes.open("shell32.dll");

    LOG("registering callback ctype WindowProc ...");
    WindowProc = ctypes.FunctionType(
        ctypes.stdcall_abi, ctypes.int, 
        [ctypes.voidptr_t, ctypes.int32_t, 
         ctypes.int32_t, ctypes.int32_t]).ptr;

    LOG("registering API CreateWindowEx ...");
    CreateWindowEx = libs.user32.declare("CreateWindowExA", 
        ctypes.winapi_abi, ctypes.voidptr_t, ctypes.long, 
        ctypes.char.ptr, ctypes.char.ptr, ctypes.int,
        ctypes.int, ctypes.int, ctypes.int, ctypes.int, 
        ctypes.voidptr_t, ctypes.voidptr_t, ctypes.voidptr_t, 
        ctypes.voidptr_t);

    LOG("registering API DestroyWindow ...");
    DestroyWindow = libs.user32.declare("DestroyWindow", 
        ctypes.winapi_abi, ctypes.bool, ctypes.voidptr_t);

    /*

    // previously using....

    LOG("registering ctype SHITEMID ...");
    var ShItemId = ctypes.StructType("ShItemId", [
      { cb: ctypes.unsigned_short },
      { abID: ctypes.uint8_t.array(1) }
    ]);

    LOG("registering ctype ITEMIDLIST ...");
    var ItemIDList = ctypes.StructType("ItemIDList", [
      { mkid: ShItemId }
    ]);

    */

    LOG("registering ctype SHChangeNotifyEntry ...");
    var SHChangeNotifyEntry = ctypes.StructType(
        "SHChangeNotifyEntry", [
            { pidl: ctypes.long.ptr   }, /* ItemIDList.ptr ??? */
            { fRecursive: ctypes.bool }
        ]);

    LOG("registering API SHChangeNotifyRegister ...");
    SHChangeNotifyRegister = libs.shell32.declare(
      "SHChangeNotifyRegister", ctypes.winapi_abi, 
      ctypes.unsigned_long, 
      ctypes.voidptr_t, ctypes.int, ctypes.long, 
      ctypes.unsigned_int,  ctypes.int, 
      SHChangeNotifyEntry.array() /* SHChangeNotifyEntry.ptr ??? */
    );

    LOG("registering ctype WNDCLASS ...");
    WNDCLASS = ctypes.StructType("WNDCLASS", [
      { style          : ctypes.uint32_t  },
      { lpfnWndProc    : WindowProc       }, 
      { cbClsExtra     : ctypes.int32_t   },
      { cbWndExtra     : ctypes.int32_t   },
      { hInstance      : ctypes.voidptr_t },
      { hIcon          : ctypes.voidptr_t },
      { hCursor        : ctypes.voidptr_t },
      { hbrBackground  : ctypes.voidptr_t },
      { lpszMenuName   : ctypes.char.ptr  },
      { lpszClassName  : ctypes.char.ptr  }
    ]);

    LOG("registering API SHGetSpecialFolderLocation ...");
    SHGetSpecialFolderLocation = libs.shell32.declare(
      "SHGetSpecialFolderLocation", ctypes.winapi_abi, 
      ctypes.long, ctypes.voidptr_t, ctypes.int, 
      ctypes.long.ptr        /* ItemIDList.ptr ??? */
    );

    LOG("registering API RegisterClass ...");
    RegisterClass = libs.user32.declare("RegisterClassA", 
        ctypes.winapi_abi, ctypes.voidptr_t, WNDCLASS.ptr);

    LOG("registering API DefWindowProc ...");
    DefWindowProc = libs.user32.declare("DefWindowProcA", 
        ctypes.winapi_abi, ctypes.int, ctypes.voidptr_t, 
        ctypes.int32_t, ctypes.int32_t, ctypes.int32_t);

    LOG("instatiating WNDCLASS (using windowProcJSCallback) ...");
    var cName = "class-testingmessageonlywindow";
    wndclass = WNDCLASS();
    wndclass.lpszClassName = ctypes.char.array()(cName);
    wndclass.lpfnWndProc = WindowProc(windowProcJSCallback);

    LOG("calling API: RegisterClass ...");
    RegisterClass(wndclass.address());

    LOG("calling API: CreateWindowEx ...");
    var HWND_MESSAGE = -3; // message-only window
    messageWin = CreateWindowEx(
      0, wndclass.lpszClassName,
      ctypes.char.array()("my-testing-window"),
      0, 0, 0, 0, 0, 
      ctypes.voidptr_t(HWND_MESSAGE), 
      null, null, null
    );

    LOG("instantiating pidl ...");
    var pidl = ctypes.long();
    LOG("Prior to call, pidl = "+pidl);

    LOG("calling API: SHGetSpecialFolderLocation ...");
    var CSIDL_DESKTOP = 0;
    var hr = SHGetSpecialFolderLocation(
        messageWin, 
        CSIDL_DESKTOP, 
        pidl.address()
    );
    LOG("got back: "+hr);
    LOG("After the call, pidl = "+pidl);

    LOG("instantiating pschcne ...");
    var SHCNE = SHChangeNotifyEntry.array(1);
    var shcne = SHCNE();
    shcne[0].pidl = pidl.address();
    shcne[0].fRecursive = false;

    var WM_SHNOTIFY           = 1025;    // 0x401
    var SHCNE_DISKEVENTS      = 145439;  // 0x2381F
    var SHCNE_DRIVEADD        = 256;     // 256
    var SHCNE_DRIVEREMOVED    = 128;     // 128
    var SHCNE_MEDIAINSERTED   = 32;      // 32
    var SHCNE_MEDIAREMOVED    = 64;      // 64
    var SHCNRF_ShellLevel     = 2;       // 0x0002
    var SHCNRF_InterruptLevel = 1;       // 0x0001
    var SHCNRF_NewDelivery    = 32768;   // 0x8000

    var nSources = SHCNRF_ShellLevel | 
                   SHCNRF_InterruptLevel | 
                   SHCNRF_NewDelivery; 
    var lEvents  = SHCNE_DISKEVENTS | SHCNE_DRIVEADD | 
                   SHCNE_DRIVEREMOVED | SHCNE_MEDIAINSERTED | 
                   SHCNE_MEDIAREMOVED;
    var uMsg     = WM_SHNOTIFY;

    LOG("DEBUG: nSources="+nSources);
    LOG("DEBUG: lEvents="+lEvents);
    LOG("DEBUG: uMsg="+uMsg);

    LOG("calling API: SHChangeNotifyRegister ...");
    var reg_id = SHChangeNotifyRegister(
        messageWin, nSources, lEvents, uMsg, 1, shcne
    );
    if (reg_id > 0) {
      LOG("SUCCESS: Registered with ShellService for "+
          "DRIVE/MEDIA notifications! reg-id: "+reg_id);
    } else {
      LOG("ERROR: Couldn't register for DRIVE/MEDIA "+
          "notifications from ShellService!");
    }       

    LOG("done!");
  } catch (e) {
    LOG("ERROR: "+e);
  }
}

function shutdown(data, reason) {
  if (reason == APP_SHUTDOWN) return;
  try {

    //LOG("destroying hidden window... ");
    //DestroyWindow(messageWin);  // crash!!!

    LOG("unloading USER32.DLL ...");
    libs.user32.close();

    LOG("unloading SHELL32.DLL ...");
    libs.shell32.close();

    LOG("done!");
  } catch (e) {
    LOG("ERROR: "+e);
  }
}

---

控制台输出:

17:08:25.518 TEST-WNDPROC: loading USER32.DLL ...
17:08:25.518 TEST-WNDPROC: loading SHELL32.DLL ...
17:08:25.518 TEST-WNDPROC: registering callback ctype WindowProc ...
17:08:25.518 TEST-WNDPROC: registering API CreateWindowEx ...
17:08:25.518 TEST-WNDPROC: registering API DestroyWindow ...
17:08:25.518 TEST-WNDPROC: registering ctype SHChangeNotifyEntry ...
17:08:25.518 TEST-WNDPROC: registering API SHChangeNotifyRegister ...
17:08:25.518 TEST-WNDPROC: registering ctype WNDCLASS ...
17:08:25.518 TEST-WNDPROC: registering API SHGetSpecialFolderLocation ...
17:08:25.518 TEST-WNDPROC: registering API RegisterClass ...
17:08:25.518 TEST-WNDPROC: registering API DefWindowProc ...
17:08:25.519 TEST-WNDPROC: instatiating WNDCLASS (using windowProcJSCallback) ...
17:08:25.519 TEST-WNDPROC: calling API: RegisterClass ...
17:08:25.519 TEST-WNDPROC: calling API: CreateWindowEx ...
17:08:25.519 TEST-WNDPROC: windowProc: [36,0,2973696]
17:08:25.519 TEST-WNDPROC: windowProc: [129,0,2973652]
17:08:25.519 TEST-WNDPROC: windowProc: [131,0,2973728]
17:08:25.519 TEST-WNDPROC: windowProc: [1,0,2973608]
17:08:25.519 TEST-WNDPROC: instantiating pidl ...
17:08:25.519 TEST-WNDPROC: Prior to call, pidl = ctypes.long(ctypes.Int64("0"))
17:08:25.519 TEST-WNDPROC: calling API: SHGetSpecialFolderLocation ...
17:08:25.519 TEST-WNDPROC: got back: 0
17:08:25.519 TEST-WNDPROC: After the call, pidl = ctypes.long(ctypes.Int64("224974424"))
17:08:25.519 TEST-WNDPROC: instantiating pschcne ...
17:08:25.519 TEST-WNDPROC: DEBUG: [nSources=32771][lEvents=145919][uMsg=1025]
17:08:25.519 TEST-WNDPROC: calling API: SHChangeNotifyRegister ...
17:08:25.520 TEST-WNDPROC: SUCCESS: Registered with ShellService for DRIVE/MEDIA
                           notifications! reg-id: 15
17:08:25.520 TEST-WNDPROC: done!
----- &< -------
17:09:31.391 TEST-WNDPROC: unloading USER32.DLL ...
17:09:31.391 TEST-WNDPROC: unloading SHELL32.DLL ...
17:09:31.391 TEST-WNDPROC: done!

Answer 1

对于其他想要这样做的人，我发布了一个令人讨厌的解决方法。（我不会接受这个答案，希望最终有人会发布如何正确地做到这一点）。

经过大量阅读后，我唯一推荐的枚举和/或确定 USB 卷状态的方法是使用 WMI。下面的WQL查询就达到了目的：

select Caption, Size from win32_LogicalDisk where DriveType = 2

要从 C++ 使用 WQL，您必须使用 COM。使用它js-ctypes并不是一项无关紧要的工程任务。您需要安排从 a 加载和使用 DLL ChromeWorker，有时我发现我特别需要确保从正确的 Firefox 线程调用 JavaScript 回调函数，并且 COM 未在多线程单元中初始化。

Caption是驱动器盘符。一旦 USB 驱动器弹出，似乎Size报告为零。

然后，在线程内的轮询循环中调用它ChromeWorker，对已安装卷的更改进行建模，并在 DOM 窗口中引发合成的 USB 安装/弹出/删除事件，就相当简单了。

不幸的是，这有一个大问题。如果插入 USB 闪存驱动器，Windows 通常需要 2 到 30 秒（取决于大小）来安装。在此期间（特别是在第一秒左右），如果运行上述WQL查询，它将阻止操作系统安装 USB 卷（？！？），从而有效地导致拒绝服务。

不管这给我带来了多大的怀疑，在询问之后我确信如果我使用asynchronous（而不是synchronous或semisynchronous）WQL 查询，就不会发生拒绝服务。

SELECT * FROM __instanceoperationevent WITHIN 2 
WHERE TargetInstance ISA 'Win32_LogicalDisk' and TargetInstance.DriveType = 2

如果是__instanceoperationeventISA __InstanceCreationEvent，则添加卷。如果是__instanceoperationeventISA __InstanceDeletionEvent，则该卷已被删除。

似乎当ISA时卷被弹出，但我不清楚其他类型的操作可能会导致这种情况。由于此时卷仍处于连接状态，因此使用第一个查询（上面）进行检查可能是安全的。__instanceoperationevent__InstanceModificationEventSizesynchronous

asynchronousWQL 查询似乎可以通过两种不同的方式调用，或者作为temporaryWMIpermanent事件使用者。差异并不大，但permanent过滤器+消费者似乎是推荐的，并且似乎不会与 WQL 查询“配额”发生冲突。

无论哪种方式，都没有明智的方法来使用via 传入的JavaScript 回调来处理生成的WMI 事件js-ctypes。:-( 这就需要寻找一种方法来使用事件，然后将它们传回 Firefox。

我最终使用了基于DBD::WMI 的Strawberry Perl 脚本，每 2 秒异步轮询一次事件，然后使用IO::Socket::INET通过将结果发送给 Firefox 来将结果发送给 Firefox。 TCP 套接字。（你可以用任何语言来做这件事 - 我碰巧对 Perl 很满意）。

然后，我从插件内部实现nsIServerSocket，等待\n终止的行来解析收集的输入并执行与上述相同的建模和合成事件。