| |
| /* Support for dynamic loading of extension modules */ |
| |
| #include "Python.h" |
| #include "pycore_fileutils.h" // _Py_add_relfile() |
| #include "pycore_pystate.h" // _PyInterpreterState_GET() |
| |
| #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; |
| |
| /* Don't claim that python3.dll is a Python DLL. */ |
| #ifdef _DEBUG |
| if (strcmp(import_name, "python3_d.dll") == 0) { |
| #else |
| if (strcmp(import_name, "python3.dll") == 0) { |
| #endif |
| import_data += 20; |
| continue; |
| } |
| |
| /* 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; |
| } |
| |
| /* Load python3.dll before loading any extension module that might refer |
| to it. That way, we can be sure that always the python3.dll corresponding |
| to this python DLL is loaded, not a python3.dll that might be on the path |
| by chance. |
| Return whether the DLL was found. |
| */ |
| extern HMODULE PyWin_DLLhModule; |
| static int |
| _Py_CheckPython3(void) |
| { |
| static int python3_checked = 0; |
| static HANDLE hPython3; |
| #define MAXPATHLEN 512 |
| wchar_t py3path[MAXPATHLEN+1]; |
| if (python3_checked) { |
| return hPython3 != NULL; |
| } |
| python3_checked = 1; |
| |
| /* If there is a python3.dll next to the python3y.dll, |
| use that DLL */ |
| if (PyWin_DLLhModule && GetModuleFileNameW(PyWin_DLLhModule, py3path, MAXPATHLEN)) { |
| wchar_t *p = wcsrchr(py3path, L'\\'); |
| if (p) { |
| wcscpy(p + 1, PY3_DLLNAME); |
| hPython3 = LoadLibraryExW(py3path, NULL, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS); |
| if (hPython3 != NULL) { |
| return 1; |
| } |
| } |
| } |
| |
| /* If we can locate python3.dll in our application dir, |
| use that DLL */ |
| hPython3 = LoadLibraryExW(PY3_DLLNAME, NULL, LOAD_LIBRARY_SEARCH_APPLICATION_DIR); |
| if (hPython3 != NULL) { |
| return 1; |
| } |
| |
| /* For back-compat, also search {sys.prefix}\DLLs, though |
| that has not been a normal install layout for a while */ |
| PyInterpreterState *interp = _PyInterpreterState_GET(); |
| PyConfig *config = (PyConfig*)_PyInterpreterState_GetConfig(interp); |
| assert(config->prefix); |
| if (config->prefix) { |
| wcscpy_s(py3path, MAXPATHLEN, config->prefix); |
| if (py3path[0] && _Py_add_relfile(py3path, L"DLLs\\" PY3_DLLNAME, MAXPATHLEN) >= 0) { |
| hPython3 = LoadLibraryExW(py3path, NULL, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS); |
| } |
| } |
| return hPython3 != NULL; |
| #undef MAXPATHLEN |
| } |
| |
| 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; |
| } |
