从C#调用Advapi32.dll本机EventWrite函数

Question

我正在尝试使用C#.Net来触发Window的服务触发事件。

具体来说，我正在尝试触发此事件，以便从一个无特权帐户启动WebClient服务。

C:>sc qtriggerinfo WebClient
[SC] QueryServiceConfig2 SUCCESS
SERVICE_NAME: WebClient
        START SERVICE
          CUSTOM                       : 22b6d684-fa63-4578-87c9-effcbe6643c7 [ETW PROVIDER UUID]

我在C++中启动服务时找到了这个参考，但不确定如何在C#中实现相同的功能：

bool StartWebClientService()
{
    const GUID _MS_Windows_WebClntLookupServiceTrigger_Provider =
        { 0x22B6D684, 0xFA63, 0x4578, 
        { 0x87, 0xC9, 0xEF, 0xFC, 0xBE, 0x66, 0x43, 0xC7 } };
    REGHANDLE Handle;
    bool success = false;
    if (EventRegister(&_MS_Windows_WebClntLookupServiceTrigger_Provider,
        nullptr, nullptr, &Handle) == ERROR_SUCCESS)
    {
        EVENT_DESCRIPTOR desc;
        EventDescCreate(&desc, 1, 0, 0, 4, 0, 0, 0);
        success = EventWrite(Handle, &desc, 0, nullptr) == ERROR_SUCCESS;
        EventUnregister(Handle);
    }
    return success;
}

这是我正在使用的代码：

[StructLayout(LayoutKind.Explicit, Size=12)]
public class EVENT_DESCRIPTOR
{
    [FieldOffset(0)]ushort Id = 1;
    [FieldOffset(2)]byte Version = 0;
    [FieldOffset(3)]byte Channel = 0;
    [FieldOffset(4)]byte Level = 4;
    [FieldOffset(5)]byte Opcode = 0;
    [FieldOffset(6)]ushort Task = 0;
    [FieldOffset(8)]ulong Keyword = 0;
}
//...
    void startService()
    {
        Guid webCleintTrigger = new Guid(0x22B6D684, 0xFA63, 0x4578, 0x87, 0xC9, 0xEF, 0xFC, 0xBE, 0x66, 0x43, 0xC7);
        IntPtr handle;
        uint output = EventRegister(ref webCleintTrigger, IntPtr.Zero, IntPtr.Zero, out handle);
        //This is what is returned:
        //output = 0 <- Good 
        //handle = 65537  <- Good handle?
        bool success = false;
        if (output == 0)
        {
            //Create event descriptor
            EVENT_DESCRIPTOR desc = new EVENT_DESCRIPTOR();
            //Write the event
            uint writeOutput = EventWrite(handle, ref desc, 0, IntPtr.Zero); //Throws PInvokeStackImbalance
            success = writeOutput == 0;
            EventUnregister(handle);
        }
    }
    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern uint EventRegister(ref Guid guid, [Optional] IntPtr EnableCallback, [Optional] IntPtr CallbackContext, out IntPtr RegHandle);
    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern uint EventWrite(IntPtr RegHandle, ref EVENT_DESCRIPTOR EventDescriptor, uint UserDataCount, [Optional] IntPtr UserData);
    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern uint EventUnregister(IntPtr RegHandle);

对EventWrite的调用引发PInvokeStackImbalance异常。这可能是我的EVENT_DESCRIPTOR结构错误吗？

这是本机Event_Descriptor:的结构

typedef struct _EVENT_DESCRIPTOR {
  USHORT    Id;
  UCHAR     Version;
  UCHAR     Channel;
  UCHAR     Level;
  UCHAR     Opcode;
  USHORT    Task;
  ULONGLONG Keyword;
} EVENT_DESCRIPTOR, *PEVENT_DESCRIPTOR;typedef const EVENT_DESCRIPTOR *PCEVENT_DESCRIPTOR;

这是我的C#结构：

[StructLayout(LayoutKind.Explicit, Size=16)]
public class EVENT_DESCRIPTOR
{
    [FieldOffset(0)]ushort Id = 1;
    [FieldOffset(2)]byte Version = 0;
    [FieldOffset(3)]byte Channel = 0;
    [FieldOffset(4)]byte Level = 4;
    [FieldOffset(5)]byte Opcode = 0;
    [FieldOffset(6)]ushort Task = 0;
    [FieldOffset(8)]ulong Keyword = 0;
}

这是本机EventWrite函数的结构：

ULONG EventWrite(
  _In_      REGHANDLE RegHandle,
  _In_      PCEVENT_DESCRIPTOR EventDescriptor,
  _In_      ULONG UserDataCount,
  _In_opt_  PEVENT_DATA_DESCRIPTOR UserData
);

这是我对Event Write:的PInvoke调用

    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern uint EventWrite(IntPtr RegHandle, ref EVENT_DESCRIPTOR EventDescriptor, uint UserDataCount, [Optional] IntPtr UserData);

这是我正在进行的调用，它抛出PInvokeStackImbalance异常：

    EVENT_DESCRIPTOR desc = new EVENT_DESCRIPTOR();
    uint writeOutput = EventWrite(handle, ref desc, 0, IntPtr.Zero); //Throws PInvokeStackImbalance

Answer 1

感谢BenVoigt向我介绍他们已经实现PInvoke调用的Microsoft源代码参考。

这就是解决方案：

[StructLayout(LayoutKind.Explicit, Size=16)]
public class EVENT_DESCRIPTOR
{
    [FieldOffset(0)]ushort Id = 1;
    [FieldOffset(2)]byte Version = 0;
    [FieldOffset(3)]byte Channel = 0;
    [FieldOffset(4)]byte Level = 4;
    [FieldOffset(5)]byte Opcode = 0;
    [FieldOffset(6)]ushort Task = 0;
    [FieldOffset(8)]long Keyword = 0;
}
[StructLayout(LayoutKind.Explicit, Size = 16)]
public struct EventData
{
    [FieldOffset(0)]
    internal UInt64 DataPointer;
    [FieldOffset(8)]
    internal uint Size;
    [FieldOffset(12)]
    internal int Reserved;
}
//...
    void startService()
    {
        Guid webCleintTrigger = new Guid(0x22B6D684, 0xFA63, 0x4578, 0x87, 0xC9, 0xEF, 0xFC, 0xBE, 0x66, 0x43, 0xC7);
        long handle = 0;
        uint output = EventRegister(ref webCleintTrigger, IntPtr.Zero, IntPtr.Zero, ref handle);
        //This is what is returned:
        //output = 0 <- Good 
        //handle = 65537  <- Good handle?
        bool success = false;
        if (output == 0)
        {
            //Create event descriptor
            EVENT_DESCRIPTOR desc = new EVENT_DESCRIPTOR();
            //Write the event
            unsafe
            {
                uint writeOutput = EventWrite(handle, ref desc, 0, null);
                success = writeOutput == 0;
                EventUnregister(handle);
            }
        }
    }
    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern uint EventRegister(ref Guid guid, [Optional] IntPtr EnableCallback, [Optional] IntPtr CallbackContext, [In][Out] ref long RegHandle);
    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern unsafe uint EventWrite(long RegHandle, ref EVENT_DESCRIPTOR EventDescriptor, uint UserDataCount, EventData* UserData);
    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern uint EventUnregister(long RegHandle);