頭文件
/*****MemLoadDll.h*****/
#if !defined(Q_OS_LINUX)
#pragma once
typedef BOOL (__stdcall *ProcDllMain)(HINSTANCE, DWORD, LPVOID );
class CMemLoadDll
{
public:
CMemLoadDll();
~CMemLoadDll();
BOOL MemLoadLibrary( void *lpFileData , int DataLength); // Dll file data buffer
FARPROC MemGetProcAddress(LPCSTR lpProcName);
private:
BOOL isLoadOk;
BOOL CheckDataValide(void *lpFileData, int DataLength);
int CalcTotalImageSize();
void CopyDllDatas(void *pDest, void *pSrc);
BOOL FillRavAddress(void *pBase);
void DoRelocation(void *pNewBase);
int GetAlignedSize(int Origin, int Alignment);
private:
ProcDllMain pDllMain;
private:
DWORD pImageBase;
PIMAGE_DOS_HEADER pDosHeader;
PIMAGE_NT_HEADERS pNTHeader;
PIMAGE_SECTION_HEADER pSectionHeader;
};
#endif源文件
/*****MemLoadDll.cpp*****/
#if !defined(Q_OS_LINUX)
#include <windows.h>
#include <assert.h>
#include "MemLoadDll.h"
#include "QDebug"
CMemLoadDll::CMemLoadDll()
{
isLoadOk = FALSE;
pImageBase = NULL;
pDllMain = NULL;
}
CMemLoadDll::~CMemLoadDll()
{
if(isLoadOk)
{
assert(pImageBase != NULL);
assert(pDllMain != NULL);
//脫鉤，準備卸載dll
pDllMain((HINSTANCE)pImageBase,DLL_PROCESS_DETACH,0);
VirtualFree((LPVOID)pImageBase, 0, MEM_RELEASE);
}
}
//MemLoadLibrary函數從內存緩衝區數據中加載一個dll到當前進程的地址空間，缺省位置0x10000000
//返回值： 成功返回TRUE , 失敗返回FALSE
//lpFileData: 存放dll文件數據的緩衝區
//DataLength: 緩衝區中數據的總長度
BOOL CMemLoadDll::MemLoadLibrary(void *lpFileData, int DataLength)
{
if (pImageBase != NULL)
{
return FALSE; //已經加載一個dll，還沒有釋放，不能加載新的dll
}
//檢查數據有效性，並初始化
if (!CheckDataValide(lpFileData, DataLength))
{
return FALSE;
}
//計算所需的加載空間
int ImageSize = CalcTotalImageSize();
if (ImageSize == 0)
{
return FALSE;
}
// 分配虛擬內存
void *pMemoryAddress = VirtualAlloc((LPVOID)NULL, ImageSize,
MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if (pMemoryAddress == NULL)
{
return FALSE;
}
else
{
CopyDllDatas(pMemoryAddress, lpFileData); //複製dll數據，並對齊每個段
//重定位信息
if (pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].VirtualAddress > 0
&& pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].Size > 0)
{
DoRelocation(pMemoryAddress);
}
//填充引入地址表
if (!FillRavAddress(pMemoryAddress)) //修正引入地址表失敗
{
VirtualFree(pMemoryAddress, 0, MEM_RELEASE);
return FALSE;
}
//修改頁屬性。應該根據每個頁的屬性單獨設置其對應內存頁的屬性。這裏簡化一下。
//統一設置成一個屬性PAGE_EXECUTE_READWRITE
unsigned long old;
VirtualProtect(pMemoryAddress, ImageSize, PAGE_EXECUTE_READWRITE, &old);
}
//修正基地址
pNTHeader->OptionalHeader.ImageBase = (DWORD)pMemoryAddress;
//接下來要調用一下dll的入口函數，做初始化工作。
pDllMain = (ProcDllMain)(pNTHeader->OptionalHeader.AddressOfEntryPoint + (DWORD) pMemoryAddress);
BOOL InitResult = pDllMain((HINSTANCE)pMemoryAddress, DLL_PROCESS_ATTACH, 0);
if (!InitResult) //初始化失敗
{
pDllMain((HINSTANCE)pMemoryAddress, DLL_PROCESS_DETACH, 0);
VirtualFree(pMemoryAddress, 0, MEM_RELEASE);
pDllMain = NULL;
return FALSE;
}
isLoadOk = TRUE;
pImageBase = (DWORD)pMemoryAddress;
return TRUE;
}
//MemGetProcAddress函數從dll中獲取指定函數的地址
//返回值： 成功返回函數地址 , 失敗返回NULL
//lpProcName: 要查找函數的名字或者序號
FARPROC CMemLoadDll::MemGetProcAddress(LPCSTR lpProcName)
{
if (pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress == 0 ||
pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].Size == 0)
{
return NULL;
}
if (!isLoadOk)
{
return NULL;
}
DWORD OffsetStart = pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress;
DWORD Size = pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].Size;
PIMAGE_EXPORT_DIRECTORY pExport = (PIMAGE_EXPORT_DIRECTORY)((DWORD)pImageBase + pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress);
int iBase = pExport->Base;
int iNumberOfFunctions = pExport->NumberOfFunctions;
int iNumberOfNames = pExport->NumberOfNames; //<= iNumberOfFunctions
LPDWORD pAddressOfFunctions = (LPDWORD)(pExport->AddressOfFunctions + pImageBase);
LPWORD pAddressOfOrdinals = (LPWORD)(pExport->AddressOfNameOrdinals + pImageBase);
LPDWORD pAddressOfNames = (LPDWORD)(pExport->AddressOfNames + pImageBase);
int iOrdinal = -1;
if (((DWORD)lpProcName & 0xFFFF0000) == 0) //IT IS A ORDINAL!
{
iOrdinal = (DWORD)lpProcName & 0x0000FFFF - iBase;
}
else //use name
{
int iFound = -1;
for (int i = 0; i < iNumberOfNames; i++)
{
char *pName = (char * )(pAddressOfNames[i] + pImageBase);
if (strcmp(pName, lpProcName) == 0)
{
iFound = i;
break;
}
}
if (iFound >= 0)
{
iOrdinal = (int)(pAddressOfOrdinals[iFound]);
}
}
if (iOrdinal < 0 || iOrdinal >= iNumberOfFunctions )
{
return NULL;
}
else
{
DWORD pFunctionOffset = pAddressOfFunctions[iOrdinal];
if (pFunctionOffset > OffsetStart && pFunctionOffset < (OffsetStart + Size)) //maybe Export Forwarding
{
return NULL;
}
else
{
return (FARPROC)(pFunctionOffset + pImageBase);
}
}
}
// 重定向PE用到的地址
void CMemLoadDll::DoRelocation( void *NewBase)
{
/* 重定位表的結構：
// DWORD sectionAddress, DWORD size (包括本節需要重定位的數據)
// 例如 1000節需要修正5個重定位數據的話，重定位表的數據是
// 00 10 00 00 14 00 00 00 xxxx xxxx xxxx xxxx xxxx 0000
// ----------- ----------- ----
// 給出節的偏移 總尺寸=8+6*2 需要修正的地址 用於對齊4字節
// 重定位表是若干個相連，如果address 和 size都是0 表示結束
// 需要修正的地址是12位的，高4位是形態字，intel cpu下是3
*/
//假設NewBase是0x600000,而文件中設置的缺省ImageBase是0x400000,則修正偏移量就是0x200000
DWORD Delta = (DWORD)NewBase - pNTHeader->OptionalHeader.ImageBase;
//注意重定位表的位置可能和硬盤文件中的偏移地址不同，應該使用加載後的地址
PIMAGE_BASE_RELOCATION pLoc = (PIMAGE_BASE_RELOCATION)((unsigned long)NewBase
+ pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BASERELOC].VirtualAddress);
while ((pLoc->VirtualAddress + pLoc->SizeOfBlock) != 0) //開始掃描重定位表
{
WORD *pLocData = (WORD *)((int)pLoc + sizeof(IMAGE_BASE_RELOCATION));
//計算本節需要修正的重定位項（地址）的數目
int NumberOfReloc = (pLoc->SizeOfBlock - sizeof(IMAGE_BASE_RELOCATION)) / sizeof(WORD);
for ( int i = 0 ; i < NumberOfReloc; i++)
{
if ( (DWORD)(pLocData[i] & 0xF000) == 0x00003000) //這是一個需要修正的地址
{
// 舉例：
// pLoc->VirtualAddress = 0x1000;
// pLocData[i] = 0x313E; 表示本節偏移地址0x13E處需要修正
// 因此 pAddress = 基地址 + 0x113E
// 裏面的內容是 A1 ( 0c d4 02 10) 彙編代碼是： mov eax , [1002d40c]
// 需要修正1002d40c這個地址
DWORD *pAddress = (DWORD *)((unsigned long)NewBase + pLoc->VirtualAddress + (pLocData[i] & 0x0FFF));
*pAddress += Delta;
}
}
//轉移到下一個節進行處理
pLoc = (PIMAGE_BASE_RELOCATION)((DWORD)pLoc + pLoc->SizeOfBlock);
}
}
//填充引入地址表
BOOL CMemLoadDll::FillRavAddress(void *pImageBase)
{
// 引入表實際上是一個 IMAGE_IMPORT_DESCRIPTOR 結構數組，全部是0表示結束
// 數組定義如下：
//
// DWORD OriginalFirstThunk; // 0表示結束，否則指向未綁定的IAT結構數組
// DWORD TimeDateStamp;
// DWORD ForwarderChain; // -1 if no forwarders
// DWORD Name; // 給出dll的名字
// DWORD FirstThunk; // 指向IAT結構數組的地址(綁定後，這些IAT裏面就是實際的函數地址)
int i;
unsigned long Offset = pNTHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress ;
if (Offset == 0)
{
return TRUE; //No Import Table
}
PIMAGE_IMPORT_DESCRIPTOR pID = (PIMAGE_IMPORT_DESCRIPTOR)((unsigned long) pImageBase + Offset);
while (pID->Characteristics != 0 )
{
PIMAGE_THUNK_DATA pRealIAT = (PIMAGE_THUNK_DATA)((unsigned long)pImageBase + pID->FirstThunk);
PIMAGE_THUNK_DATA pOriginalIAT = (PIMAGE_THUNK_DATA)((unsigned long)pImageBase + pID->OriginalFirstThunk);
//獲取dll的名字
WCHAR buf[256]; //dll name;
BYTE *pName = (BYTE *)((unsigned long)pImageBase + pID->Name);
for (i = 0; i < 256; i++)
{
if (pName[i] == 0)
{
break;
}
buf[i] = pName[i];
}
if (i >= 256)
{
return FALSE; // bad dll name
}
else
{
buf[i] = 0;
}
HMODULE hDll = GetModuleHandle(buf);
if (hDll == NULL)
{
hDll = LoadLibrary(buf);
}
if (hDll == NULL)
{
return FALSE; //NOT FOUND DLL
}
//獲取DLL中每個導出函數的地址，填入IAT
//每個IAT結構是 ：
// union { PBYTE ForwarderString;
// PDWORD Function;
// DWORD Ordinal;
// PIMAGE_IMPORT_BY_NAME AddressOfData;
// } u1;
// 長度是一個DWORD ，正好容納一個地址。
for (i = 0; ; i++)
{
if (pOriginalIAT[i].u1.Function == 0)
{
break;
}
FARPROC lpFunction = NULL;
if (pOriginalIAT[i].u1.Ordinal & IMAGE_ORDINAL_FLAG) //這裏的值給出的是導出序號
{
lpFunction = GetProcAddress(hDll, (LPCSTR)(pOriginalIAT[i].u1.Ordinal & 0x0000FFFF));
}
else //按照名字導入
{
//獲取此IAT項所描述的函數名稱
PIMAGE_IMPORT_BY_NAME pByName = (PIMAGE_IMPORT_BY_NAME)
((DWORD)pImageBase + (DWORD)(pOriginalIAT[i].u1.AddressOfData));
// if(pByName->Hint !=0)
// lpFunction = GetProcAddress(hDll, (LPCSTR)pByName->Hint);
// else
lpFunction = GetProcAddress(hDll, (char *)pByName->Name);
}
if (lpFunction != NULL) //找到了！
{
pRealIAT[i].u1.Function = (DWORD)lpFunction;//(PDWORD) lpFunction;
}
else
{
return FALSE;
}
}
//move to next
pID = (PIMAGE_IMPORT_DESCRIPTOR)( (DWORD)pID + sizeof(IMAGE_IMPORT_DESCRIPTOR));
}
return TRUE;
}
//CheckDataValide函數用於檢查緩衝區中的數據是否有效的dll文件
//返回值： 是一個可執行的dll則返回TRUE，否則返回FALSE。
//lpFileData: 存放dll數據的內存緩衝區
//DataLength: dll文件的長度
BOOL CMemLoadDll::CheckDataValide(void *lpFileData, int DataLength)
{
//檢查長度
if (DataLength < sizeof(IMAGE_DOS_HEADER))
{
return FALSE;
}
pDosHeader = (PIMAGE_DOS_HEADER)lpFileData; // DOS頭
//檢查dos頭的標記
if (pDosHeader->e_magic != IMAGE_DOS_SIGNATURE)
{
return FALSE; //0x5A4D : MZ
}
//檢查長度
if ((DWORD)DataLength < (pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS)) )
{
return FALSE;
}
//取得pe頭
pNTHeader = (PIMAGE_NT_HEADERS)( (unsigned long)lpFileData + pDosHeader->e_lfanew); // PE頭
//檢查pe頭的合法性
if (pNTHeader->Signature != IMAGE_NT_SIGNATURE)
{
return FALSE; //0x00004550 : PE00
}
if ((pNTHeader->FileHeader.Characteristics & IMAGE_FILE_DLL) == 0) //0x2000 : File is a DLL
{
return FALSE;
}
if ((pNTHeader->FileHeader.Characteristics & IMAGE_FILE_EXECUTABLE_IMAGE) == 0) //0x0002 : 指出文件可以運行
{
return FALSE;
}
if (pNTHeader->FileHeader.SizeOfOptionalHeader != sizeof(IMAGE_OPTIONAL_HEADER))
{
return FALSE;
}
//取得節表（段表）
pSectionHeader = (PIMAGE_SECTION_HEADER)((int)pNTHeader + sizeof(IMAGE_NT_HEADERS));
//驗證每個節表的空間
for (int i = 0; i < pNTHeader->FileHeader.NumberOfSections; i++)
{
if ((pSectionHeader[i].PointerToRawData + pSectionHeader[i].SizeOfRawData) > (DWORD)DataLength)
{
return FALSE;
}
}
return TRUE;
}
//計算對齊邊界
int CMemLoadDll::GetAlignedSize(int Origin, int Alignment)
{
return (Origin + Alignment - 1) / Alignment * Alignment;
}
//計算整個dll映像文件的尺寸
int CMemLoadDll::CalcTotalImageSize()
{
int Size;
if (pNTHeader == NULL)
{
return 0;
}
int nAlign = pNTHeader->OptionalHeader.SectionAlignment; //段對齊字節數
// 計算所有頭的尺寸。包括dos, coff, pe頭 和 段表的大小
Size = GetAlignedSize(pNTHeader->OptionalHeader.SizeOfHeaders, nAlign);
// 計算所有節的大小
for (int i = 0; i < pNTHeader->FileHeader.NumberOfSections; ++i)
{
//得到該節的大小
int CodeSize = pSectionHeader[i].Misc.VirtualSize ;
int LoadSize = pSectionHeader[i].SizeOfRawData;
int MaxSize = (LoadSize > CodeSize) ? (LoadSize) : (CodeSize);
int SectionSize = GetAlignedSize(pSectionHeader[i].VirtualAddress + MaxSize, nAlign);
if (Size < SectionSize)
{
Size = SectionSize; //Use the Max;
}
}
return Size;
}
//CopyDllDatas函數將dll數據複製到指定內存區域，並對齊所有節
//pSrc: 存放dll數據的原始緩衝區
//pDest:目標內存地址
void CMemLoadDll::CopyDllDatas(void *pDest, void *pSrc)
{
// 計算需要複製的PE頭+段表字節數
int HeaderSize = pNTHeader->OptionalHeader.SizeOfHeaders;
int SectionSize = pNTHeader->FileHeader.NumberOfSections * sizeof(IMAGE_SECTION_HEADER);
int MoveSize = HeaderSize + SectionSize;
//複製頭和段信息
memmove(pDest, pSrc, MoveSize);
//複製每個節
for (int i = 0; i < pNTHeader->FileHeader.NumberOfSections; ++i)
{
if (pSectionHeader[i].VirtualAddress == 0 || pSectionHeader[i].SizeOfRawData == 0)
{
continue;
}
// 定位該節在內存中的位置
void *pSectionAddress = (void *)((unsigned long)pDest + pSectionHeader[i].VirtualAddress);
// 複製段數據到虛擬內存
memmove((void *)pSectionAddress,
(void *)((DWORD)pSrc + pSectionHeader[i].PointerToRawData),
pSectionHeader[i].SizeOfRawData);
}
//修正指針，指向新分配的內存
//新的dos頭
pDosHeader = (PIMAGE_DOS_HEADER)pDest;
//新的pe頭地址
pNTHeader = (PIMAGE_NT_HEADERS)((int)pDest + (pDosHeader->e_lfanew));
//新的節表地址
pSectionHeader = (PIMAGE_SECTION_HEADER)((int)pNTHeader + sizeof(IMAGE_NT_HEADERS));
return ;
}
#endif