| /* Support for dynamic loading of extension modules */ | |
| #include "Python.h" | |
| #ifdef HAVE_DIRECT_H | |
| #include <direct.h> | |
| #endif | |
| #include <ctype.h> | |
| #include "importdl.h" | |
| #include "patchlevel.h" | |
| #include <windows.h> | |
| #ifdef _DEBUG | |
| #define PYD_DEBUG_SUFFIX "_d" | |
| #else | |
| #define PYD_DEBUG_SUFFIX "" | |
| #endif | |
| #ifdef PYD_PLATFORM_TAG | |
| #define PYD_TAGGED_SUFFIX PYD_DEBUG_SUFFIX ".cp" Py_STRINGIFY(PY_MAJOR_VERSION) Py_STRINGIFY(PY_MINOR_VERSION) "-" PYD_PLATFORM_TAG ".pyd" | |
| #else | |
| #define PYD_TAGGED_SUFFIX PYD_DEBUG_SUFFIX ".cp" Py_STRINGIFY(PY_MAJOR_VERSION) Py_STRINGIFY(PY_MINOR_VERSION) ".pyd" | |
| #endif | |
| #define PYD_UNTAGGED_SUFFIX PYD_DEBUG_SUFFIX ".pyd" | |
| const char *_PyImport_DynLoadFiletab[] = { | |
| PYD_TAGGED_SUFFIX, | |
| PYD_UNTAGGED_SUFFIX, | |
| NULL | |
| }; | |
| /* Function to return the name of the "python" DLL that the supplied module | |
| directly imports. Looks through the list of imported modules and | |
| returns the first entry that starts with "python" (case sensitive) and | |
| is followed by nothing but numbers until the separator (period). | |
| Returns a pointer to the import name, or NULL if no matching name was | |
| located. | |
| This function parses through the PE header for the module as loaded in | |
| memory by the system loader. The PE header is accessed as documented by | |
| Microsoft in the MSDN PE and COFF specification (2/99), and handles | |
| both PE32 and PE32+. It only worries about the direct import table and | |
| not the delay load import table since it's unlikely an extension is | |
| going to be delay loading Python (after all, it's already loaded). | |
| If any magic values are not found (e.g., the PE header or optional | |
| header magic), then this function simply returns NULL. */ | |
| #define DWORD_AT(mem) (*(DWORD *)(mem)) | |
| #define WORD_AT(mem) (*(WORD *)(mem)) | |
| static char *GetPythonImport (HINSTANCE hModule) | |
| { | |
| unsigned char *dllbase, *import_data, *import_name; | |
| DWORD pe_offset, opt_offset; | |
| WORD opt_magic; | |
| int num_dict_off, import_off; | |
| /* Safety check input */ | |
| if (hModule == NULL) { | |
| return NULL; | |
| } | |
| /* Module instance is also the base load address. First portion of | |
| memory is the MS-DOS loader, which holds the offset to the PE | |
| header (from the load base) at 0x3C */ | |
| dllbase = (unsigned char *)hModule; | |
| pe_offset = DWORD_AT(dllbase + 0x3C); | |
| /* The PE signature must be "PE\0\0" */ | |
| if (memcmp(dllbase+pe_offset,"PE\0\0",4)) { | |
| return NULL; | |
| } | |
| /* Following the PE signature is the standard COFF header (20 | |
| bytes) and then the optional header. The optional header starts | |
| with a magic value of 0x10B for PE32 or 0x20B for PE32+ (PE32+ | |
| uses 64-bits for some fields). It might also be 0x107 for a ROM | |
| image, but we don't process that here. | |
| The optional header ends with a data dictionary that directly | |
| points to certain types of data, among them the import entries | |
| (in the second table entry). Based on the header type, we | |
| determine offsets for the data dictionary count and the entry | |
| within the dictionary pointing to the imports. */ | |
| opt_offset = pe_offset + 4 + 20; | |
| opt_magic = WORD_AT(dllbase+opt_offset); | |
| if (opt_magic == 0x10B) { | |
| /* PE32 */ | |
| num_dict_off = 92; | |
| import_off = 104; | |
| } else if (opt_magic == 0x20B) { | |
| /* PE32+ */ | |
| num_dict_off = 108; | |
| import_off = 120; | |
| } else { | |
| /* Unsupported */ | |
| return NULL; | |
| } | |
| /* Now if an import table exists, offset to it and walk the list of | |
| imports. The import table is an array (ending when an entry has | |
| empty values) of structures (20 bytes each), which contains (at | |
| offset 12) a relative address (to the module base) at which a | |
| string constant holding the import name is located. */ | |
| if (DWORD_AT(dllbase + opt_offset + num_dict_off) >= 2) { | |
| /* We have at least 2 tables - the import table is the second | |
| one. But still it may be that the table size is zero */ | |
| if (0 == DWORD_AT(dllbase + opt_offset + import_off + sizeof(DWORD))) | |
| return NULL; | |
| import_data = dllbase + DWORD_AT(dllbase + | |
| opt_offset + | |
| import_off); | |
| while (DWORD_AT(import_data)) { | |
| import_name = dllbase + DWORD_AT(import_data+12); | |
| if (strlen(import_name) >= 6 && | |
| !strncmp(import_name,"python",6)) { | |
| char *pch; | |
| #ifndef _DEBUG | |
| /* In a release version, don't claim that python3.dll is | |
| a Python DLL. */ | |
| if (strcmp(import_name, "python3.dll") == 0) { | |
| import_data += 20; | |
| continue; | |
| } | |
| #endif | |
| /* Ensure python prefix is followed only | |
| by numbers to the end of the basename */ | |
| pch = import_name + 6; | |
| #ifdef _DEBUG | |
| while (*pch && pch[0] != '_' && pch[1] != 'd' && pch[2] != '.') { | |
| #else | |
| while (*pch && *pch != '.') { | |
| #endif | |
| if (*pch >= '0' && *pch <= '9') { | |
| pch++; | |
| } else { | |
| pch = NULL; | |
| break; | |
| } | |
| } | |
| if (pch) { | |
| /* Found it - return the name */ | |
| return import_name; | |
| } | |
| } | |
| import_data += 20; | |
| } | |
| } | |
| return NULL; | |
| } | |
| dl_funcptr _PyImport_FindSharedFuncptrWindows(const char *prefix, | |
| const char *shortname, | |
| PyObject *pathname, FILE *fp) | |
| { | |
| dl_funcptr p; | |
| char funcname[258], *import_python; | |
| _Py_CheckPython3(); | |
| #if USE_UNICODE_WCHAR_CACHE | |
| const wchar_t *wpathname = _PyUnicode_AsUnicode(pathname); | |
| #else /* USE_UNICODE_WCHAR_CACHE */ | |
| wchar_t *wpathname = PyUnicode_AsWideCharString(pathname, NULL); | |
| #endif /* USE_UNICODE_WCHAR_CACHE */ | |
| if (wpathname == NULL) | |
| return NULL; | |
| PyOS_snprintf(funcname, sizeof(funcname), "%.20s_%.200s", prefix, shortname); | |
| { | |
| HINSTANCE hDLL = NULL; | |
| unsigned int old_mode; | |
| /* Don't display a message box when Python can't load a DLL */ | |
| old_mode = SetErrorMode(SEM_FAILCRITICALERRORS); | |
| /* bpo-36085: We use LoadLibraryEx with restricted search paths | |
| to avoid DLL preloading attacks and enable use of the | |
| AddDllDirectory function. We add SEARCH_DLL_LOAD_DIR to | |
| ensure DLLs adjacent to the PYD are preferred. */ | |
| Py_BEGIN_ALLOW_THREADS | |
| hDLL = LoadLibraryExW(wpathname, NULL, | |
| LOAD_LIBRARY_SEARCH_DEFAULT_DIRS | | |
| LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR); | |
| Py_END_ALLOW_THREADS | |
| #if !USE_UNICODE_WCHAR_CACHE | |
| PyMem_Free(wpathname); | |
| #endif /* USE_UNICODE_WCHAR_CACHE */ | |
| /* restore old error mode settings */ | |
| SetErrorMode(old_mode); | |
| if (hDLL==NULL){ | |
| PyObject *message; | |
| unsigned int errorCode; | |
| /* Get an error string from Win32 error code */ | |
| wchar_t theInfo[256]; /* Pointer to error text | |
| from system */ | |
| int theLength; /* Length of error text */ | |
| errorCode = GetLastError(); | |
| theLength = FormatMessageW( | |
| FORMAT_MESSAGE_FROM_SYSTEM | | |
| FORMAT_MESSAGE_IGNORE_INSERTS, /* flags */ | |
| NULL, /* message source */ | |
| errorCode, /* the message (error) ID */ | |
| MAKELANGID(LANG_NEUTRAL, | |
| SUBLANG_DEFAULT), | |
| /* Default language */ | |
| theInfo, /* the buffer */ | |
| sizeof(theInfo) / sizeof(wchar_t), /* size in wchars */ | |
| NULL); /* no additional format args. */ | |
| /* Problem: could not get the error message. | |
| This should not happen if called correctly. */ | |
| if (theLength == 0) { | |
| message = PyUnicode_FromFormat( | |
| "DLL load failed with error code %u while importing %s", | |
| errorCode, shortname); | |
| } else { | |
| /* For some reason a \r\n | |
| is appended to the text */ | |
| if (theLength >= 2 && | |
| theInfo[theLength-2] == '\r' && | |
| theInfo[theLength-1] == '\n') { | |
| theLength -= 2; | |
| theInfo[theLength] = '\0'; | |
| } | |
| message = PyUnicode_FromFormat( | |
| "DLL load failed while importing %s: ", shortname); | |
| PyUnicode_AppendAndDel(&message, | |
| PyUnicode_FromWideChar( | |
| theInfo, | |
| theLength)); | |
| } | |
| if (message != NULL) { | |
| PyObject *shortname_obj = PyUnicode_FromString(shortname); | |
| PyErr_SetImportError(message, shortname_obj, pathname); | |
| Py_XDECREF(shortname_obj); | |
| Py_DECREF(message); | |
| } | |
| return NULL; | |
| } else { | |
| char buffer[256]; | |
| PyOS_snprintf(buffer, sizeof(buffer), | |
| #ifdef _DEBUG | |
| "python%d%d_d.dll", | |
| #else | |
| "python%d%d.dll", | |
| #endif | |
| PY_MAJOR_VERSION,PY_MINOR_VERSION); | |
| import_python = GetPythonImport(hDLL); | |
| if (import_python && | |
| _stricmp(buffer,import_python)) { | |
| PyErr_Format(PyExc_ImportError, | |
| "Module use of %.150s conflicts " | |
| "with this version of Python.", | |
| import_python); | |
| Py_BEGIN_ALLOW_THREADS | |
| FreeLibrary(hDLL); | |
| Py_END_ALLOW_THREADS | |
| return NULL; | |
| } | |
| } | |
| Py_BEGIN_ALLOW_THREADS | |
| p = GetProcAddress(hDLL, funcname); | |
| Py_END_ALLOW_THREADS | |
| } | |
| return p; | |
| } |