Loader簡介----1

做完文件校驗後將映像映射到內存當中。

[cpp]
/*
* 將文件內容按虛擬地址信息映射到地址空間，返回模塊的基地址
*/ 
char* LdrLayoutPe(char*pImage, DWORD FileSize) 
{ 
    PIMAGE_FILE_HEADER pFileHeader; 
    PIMAGE_SECTION_HEADER pSectionHeader; 
    char* pOptionalHeader; 
    char* pImageBase; 
    char* pRealImageBase; 
    DWORD SizeOfImage; 
    WORD Magic; 
    DWORD i; 
 
    if(!LdrValidateImage(pImage, FileSize)) 
        return NULL; 
    pFileHeader = _GetFileHeaderFromPe(pImage); 
    pSectionHeader = _GetSectionHeaderFromPe(pFileHeader); 
    pOptionalHeader = (char*)pFileHeader + sizeof(IMAGE_FILE_HEADER); 
    Magic = *(WORD*)pOptionalHeader; 
    pImageBase = _GetImageBaseFromPe(pFileHeader); 
    SizeOfImage = *(DWORD*)(pOptionalHeader + 0x38); 
    pRealImageBase = (char*)VirtualAlloc(pImageBase, SizeOfImage, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE); 
    if(!pRealImageBase){ 
        pRealImageBase = (char*)VirtualAlloc(NULL, SizeOfImage, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE); 
        if(!pRealImageBase) 
            return FALSE; 
    } 
    //拷貝文件頭信息 
    RtlCopyMemory(pRealImageBase, pImage, (char*)pSectionHeader - pImage + pFileHeader->NumberOfSections*sizeof(PIMAGE_SECTION_HEADER)); 
    //拷貝節信息到內存 
    for(i = 0; i < pFileHeader->NumberOfSections; i++){ 
        if(!pSectionHeader[i].PointerToRawData) 
            continue; 
        RtlCopyMemory(pRealImageBase + pSectionHeader[i].VirtualAddress, 
            pImage + pSectionHeader[i].PointerToRawData, pSectionHeader[i].SizeOfRawData); 
    } 
    return pRealImageBase; 
} 

摘自 雲淡風輕