c - 是否可以在 Windows 上的 c-dll 中加载 go-dll？

Question

我想将一个 c-dll 注入(inject)一个进程。在 c-dll 中，它将加载另一个由 golang 编写的 dll。这是我的 C 代码:
当loader.dll被加载时，它会自动加载用golang编写的worker.dll。

// loader.c  

#include <windows.h>
#include <stdio.h>
#include <memory.h>

typedef void (*StartWorker)();
HMODULE hWorker = NULL;


BOOL APIENTRY DllMain(HMODULE hModule,
                      DWORD ul_reason_for_call,
                      LPVOID lpReserved)
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
    {

        hWorker = LoadLibrary("D:\\code\\toys\\worker.dll");
        if (hWorker == NULL)
        {
            exit(1);
        }
        
        StartWorker startWorker = (StartWorker)GetProcAddress(hWorker, "StartWorker");
        MessageBox(NULL, "worker starting", TEXT("Warning:"), MB_OK);
        if (startWorker == NULL)
        {
            MessageBox(NULL, "error", TEXT("Warning:"), MB_OK);
            exit(1);
        }
        startWorker();
        MessageBox(NULL, "worker started", TEXT("Warning:"), MB_OK);
        FreeLibrary(hWorker);
        break;
    }
    case DLL_PROCESS_DETACH:
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    default:
        break;
    }
    return TRUE;
}

去代码是:

// worker.go

package main

/*
#include <stdlib.h>
#include <windows.h>
*/
import "C"

//export StartWorker
func StartWorker {
    C.MessageBox(nil, C.CString("Hello Worker"), C.CString("Warning:"), 0)
}
func main() {
}

我已将它们编译到 MinGW-w64 .当 loader.dll 试图调用 StartWorker()在worker.dll 中，进程没有显示MessageBox。在我用c重写worker.dll后，一切正常。我也可以调用 StartWorker()通过以下代码:

#include <windows.h>
#include <stdio.h>
#include <memory.h>

typedef void (*StartWorker)();

int main()
{
    char *dllPath = "D:\\code\\toys\\loader.dll";
    HMODULE hWorker = NULL;
    hWorker = LoadLibrary(dllPath);
    StartWorker startWorker = (StartWorker)GetProcAddress(hWorker, "StartWorker");
    if (startWorker == NULL)
    {
        MessageBox(NULL, "dllPath", TEXT("Warning:"), MB_OK);
        exit(1);
    }
    startWorker();
    MessageBox(NULL, "target", TEXT("Warning:"), MB_OK);
    FreeLibrary(hWorker);
    return 0;
}

我想知道是否与 go-runtime 有任何冲突？

Answer 1

测试很好，也许你调用了 Microsoft-Windows-Only api。尝试将 MessageBox() (它使用 win32 user32.dll )更改为 Sum() 以测试称为 c-dll 的 go-dll 。
这是转到 gen go-dll 的文件
//gosum.go

package main

/*
#include <stdlib.h>
*/
import "C"

//export Sum
func Sum(a int32, b int32) int32 {
    return a + b
}

func main() {
}

去构建 c-shared Windows dll:

go build -ldflags "-s -w" -buildmode=c-shared -o gosum.dll

您可以在 c/cpp 中编写测试文件:

#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include "gosum.h"

int main() {
    printf("Sum(1,2)=%d\n", Sum(1,2));
    return 1;
}

在 MinGW-w64 中编译

g++ -c test_gosum.cpp -o test_gosum.o -g -std=c++11
g++ test_gosum.o gosum.dll -o test_gosum.exe -g -std=c++11
.\test_gosum.exe

然后在 loader.dll 中构建 Visual Studio 称为 gosum.dll//复制 go-dll CGO gen gosum.h 文件到项目，可能你需要删除一些错误代码
//gosum.h 文件:

/* Code generated by cmd/cgo; DO NOT EDIT. */

/* package gosum */


#line 1 "cgo-builtin-export-prolog"

#include <stddef.h> /* for ptrdiff_t below */

#ifndef GO_CGO_EXPORT_PROLOGUE_H
#define GO_CGO_EXPORT_PROLOGUE_H

#ifndef GO_CGO_GOSTRING_TYPEDEF
typedef struct { const char* p; ptrdiff_t n; } _GoString_;
#endif

#endif

/* Start of preamble from import "C" comments.  */


#line 3 "gosum.go"

#include <stdlib.h>

#line 1 "cgo-generated-wrapper"


/* End of preamble from import "C" comments.  */


/* Start of boilerplate cgo prologue.  */
#line 1 "cgo-gcc-export-header-prolog"

#ifndef GO_CGO_PROLOGUE_H
#define GO_CGO_PROLOGUE_H

typedef signed char GoInt8;
typedef unsigned char GoUint8;
typedef short GoInt16;
typedef unsigned short GoUint16;
typedef int GoInt32;
typedef unsigned int GoUint32;
typedef long long GoInt64;
typedef unsigned long long GoUint64;
typedef GoInt64 GoInt;
typedef GoUint64 GoUint;
typedef float GoFloat32;
typedef double GoFloat64;

/*
  static assertion to make sure the file is being used on architecture
  at least with matching size of GoInt.
*/
typedef char _check_for_64_bit_pointer_matching_GoInt[sizeof(void*) == 64 / 8 ? 1 : -1];

#ifndef GO_CGO_GOSTRING_TYPEDEF
typedef _GoString_ GoString;
#endif
typedef void* GoMap;
typedef void* GoChan;
typedef struct { void* t; void* v; } GoInterface;
typedef struct { void* data; GoInt len; GoInt cap; } GoSlice;

#endif

/* End of boilerplate cgo prologue.  */

#ifdef __cplusplus
extern "C" {
#endif
    extern GoInt32 Sum(GoInt32 a, GoInt32 b);
#ifdef __cplusplus
}
#endif

//pch.h 文件(由 vs 生成，需要添加一些东西):

#define PCH_H
#include "framework.h"
#endif

// ----- added
#ifdef IMPORT_DLL
#else
#define IMPORT_DLL extern "C" _declspec(dllimport)
#endif

IMPORT_DLL int get_sum_by_another_dll(int a, int b);

// ----- added

//dllmain.cpp 文件(由 vs 生成):

#include "pch.h"

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}

//loader.cpp 文件:

#include "pch.h"
#include <stdlib.h>
#include <windows.h>
#include "gosum.h"  // also need add `gosum.dll` to VS project file
using namespace std;

typedef int (CALLBACK* GOSUMFUNC)(GoInt32 a, GoInt32 b);

int __stdcall get_sum_by_another_dll(int a, int b)
{
    HMODULE h = LoadLibrary(TEXT("gosum.dll"));
    if (NULL == h || INVALID_HANDLE_VALUE == h) {
        return 0;
    }
    GOSUMFUNC go_dll_sum = (GOSUMFUNC)GetProcAddress(h, "Sum");
    if (go_dll_sum) {
        return go_dll_sum(a, b);
    }
    return 1;
}

然后在 VS 中编译它们，你会得到 loader.dll 。
其中 gosum.dll 是 go-dll ， loader.dll 是由 VisualStudio 编译的 c-dll ，称为 gosum.dll 。

你可以尝试在 golang 或 clang 中调用它们。
//demo.go 用 golang 测试 loader.dll 和 gosum.dll，同样需要将 gosum.dll 和 loader.dll 复制到同一个目录下。

package main

import (
    "fmt"
    "log"
    "syscall"
)

func main() {
    h, e := syscall.LoadLibrary("loader.dll")   //Make sure this DLL follows Golang machine bit architecture (64-bit in my case)
    if e != nil {
        log.Fatal(e)
    }
    defer syscall.FreeLibrary(h)
    proc, e := syscall.GetProcAddress(h, "get_sum_by_another_dll") //One of the functions in the DLL
    if e != nil {
        log.Fatal(e)
    }
    var a int32 = 2
    var b int32 = 5
    ret, _, err := syscall.Syscall(proc, 2, uintptr(a), uintptr(b), 0)  //Pay attention to the positioning of the parameter
    fmt.Println(ret)
    fmt.Println(err)
}

运行它你会得到结果: get_sum_by_another_dll(2,5) = 7
//callloader.cpp 用c/cpp测试loader.dll和gosum.dll，同样需要将 gosum.dll和 loader.dll复制到同一个目录下。

#include <iostream>
#include <Windows.h>

int main()
{
    HINSTANCE hDllInst;
    hDllInst = LoadLibrary(L"loader.dll");
    typedef int(*SUMFUNC)(int a, int b);
    SUMFUNC dll_sum_fun = (SUMFUNC)GetProcAddress(hDllInst, "get_sum_by_another_dll"); 
    std::cout << dll_sum_fun(1, 2);
}

然后在VS中编译，运行./callloader.exe，你会得到结果: get_sum_by_another_dll(1,2) = 3