diff options
Diffstat (limited to 'Modules/posixmodule.c')
-rw-r--r-- | Modules/posixmodule.c | 387 |
1 files changed, 206 insertions, 181 deletions
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c index 4f8c074..2302678 100644 --- a/Modules/posixmodule.c +++ b/Modules/posixmodule.c @@ -1625,6 +1625,7 @@ win32_wchdir(LPCWSTR path) */ #define HAVE_STAT_NSEC 1 #define HAVE_STRUCT_STAT_ST_FILE_ATTRIBUTES 1 +#define HAVE_STRUCT_STAT_ST_REPARSE_TAG 1 static void find_data_to_file_info(WIN32_FIND_DATAW *pFileData, @@ -1658,136 +1659,178 @@ attributes_from_dir(LPCWSTR pszFile, BY_HANDLE_FILE_INFORMATION *info, ULONG *re return TRUE; } -static BOOL -get_target_path(HANDLE hdl, wchar_t **target_path) -{ - int buf_size, result_length; - wchar_t *buf; - - /* We have a good handle to the target, use it to determine - the target path name (then we'll call lstat on it). */ - buf_size = GetFinalPathNameByHandleW(hdl, 0, 0, - VOLUME_NAME_DOS); - if(!buf_size) - return FALSE; - - buf = (wchar_t *)PyMem_RawMalloc((buf_size + 1) * sizeof(wchar_t)); - if (!buf) { - SetLastError(ERROR_OUTOFMEMORY); - return FALSE; - } - - result_length = GetFinalPathNameByHandleW(hdl, - buf, buf_size, VOLUME_NAME_DOS); - - if(!result_length) { - PyMem_RawFree(buf); - return FALSE; - } - - buf[result_length] = 0; - - *target_path = buf; - return TRUE; -} - static int win32_xstat_impl(const wchar_t *path, struct _Py_stat_struct *result, BOOL traverse) { - int code; - HANDLE hFile, hFile2; - BY_HANDLE_FILE_INFORMATION info; - ULONG reparse_tag = 0; - wchar_t *target_path; - const wchar_t *dot; + HANDLE hFile; + BY_HANDLE_FILE_INFORMATION fileInfo; + FILE_ATTRIBUTE_TAG_INFO tagInfo = { 0 }; + DWORD fileType, error; + BOOL isUnhandledTag = FALSE; + int retval = 0; - hFile = CreateFileW( - path, - FILE_READ_ATTRIBUTES, /* desired access */ - 0, /* share mode */ - NULL, /* security attributes */ - OPEN_EXISTING, - /* FILE_FLAG_BACKUP_SEMANTICS is required to open a directory */ - /* FILE_FLAG_OPEN_REPARSE_POINT does not follow the symlink. - Because of this, calls like GetFinalPathNameByHandle will return - the symlink path again and not the actual final path. */ - FILE_ATTRIBUTE_NORMAL|FILE_FLAG_BACKUP_SEMANTICS| - FILE_FLAG_OPEN_REPARSE_POINT, - NULL); + DWORD access = FILE_READ_ATTRIBUTES; + DWORD flags = FILE_FLAG_BACKUP_SEMANTICS; /* Allow opening directories. */ + if (!traverse) { + flags |= FILE_FLAG_OPEN_REPARSE_POINT; + } + hFile = CreateFileW(path, access, 0, NULL, OPEN_EXISTING, flags, NULL); if (hFile == INVALID_HANDLE_VALUE) { - /* Either the target doesn't exist, or we don't have access to - get a handle to it. If the former, we need to return an error. - If the latter, we can use attributes_from_dir. */ - DWORD lastError = GetLastError(); - if (lastError != ERROR_ACCESS_DENIED && - lastError != ERROR_SHARING_VIOLATION) - return -1; - /* Could not get attributes on open file. Fall back to - reading the directory. */ - if (!attributes_from_dir(path, &info, &reparse_tag)) - /* Very strange. This should not fail now */ - return -1; - if (info.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - if (traverse) { - /* Should traverse, but could not open reparse point handle */ - SetLastError(lastError); + /* Either the path doesn't exist, or the caller lacks access. */ + error = GetLastError(); + switch (error) { + case ERROR_ACCESS_DENIED: /* Cannot sync or read attributes. */ + case ERROR_SHARING_VIOLATION: /* It's a paging file. */ + /* Try reading the parent directory. */ + if (!attributes_from_dir(path, &fileInfo, &tagInfo.ReparseTag)) { + /* Cannot read the parent directory. */ + SetLastError(error); return -1; } - } - } else { - if (!GetFileInformationByHandle(hFile, &info)) { - CloseHandle(hFile); - return -1; - } - if (info.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - if (!win32_get_reparse_tag(hFile, &reparse_tag)) { - CloseHandle(hFile); - return -1; + if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { + if (traverse || + !IsReparseTagNameSurrogate(tagInfo.ReparseTag)) { + /* The stat call has to traverse but cannot, so fail. */ + SetLastError(error); + return -1; + } } - /* Close the outer open file handle now that we're about to - reopen it with different flags. */ - if (!CloseHandle(hFile)) + break; + + case ERROR_INVALID_PARAMETER: + /* \\.\con requires read or write access. */ + hFile = CreateFileW(path, access | GENERIC_READ, + FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, + OPEN_EXISTING, flags, NULL); + if (hFile == INVALID_HANDLE_VALUE) { + SetLastError(error); return -1; + } + break; + case ERROR_CANT_ACCESS_FILE: + /* bpo37834: open unhandled reparse points if traverse fails. */ if (traverse) { - /* In order to call GetFinalPathNameByHandle we need to open - the file without the reparse handling flag set. */ - hFile2 = CreateFileW( - path, FILE_READ_ATTRIBUTES, FILE_SHARE_READ, - NULL, OPEN_EXISTING, - FILE_ATTRIBUTE_NORMAL|FILE_FLAG_BACKUP_SEMANTICS, - NULL); - if (hFile2 == INVALID_HANDLE_VALUE) - return -1; + traverse = FALSE; + isUnhandledTag = TRUE; + hFile = CreateFileW(path, access, 0, NULL, OPEN_EXISTING, + flags | FILE_FLAG_OPEN_REPARSE_POINT, NULL); + } + if (hFile == INVALID_HANDLE_VALUE) { + SetLastError(error); + return -1; + } + break; - if (!get_target_path(hFile2, &target_path)) { - CloseHandle(hFile2); - return -1; - } + default: + return -1; + } + } - if (!CloseHandle(hFile2)) { - return -1; + if (hFile != INVALID_HANDLE_VALUE) { + /* Handle types other than files on disk. */ + fileType = GetFileType(hFile); + if (fileType != FILE_TYPE_DISK) { + if (fileType == FILE_TYPE_UNKNOWN && GetLastError() != 0) { + retval = -1; + goto cleanup; + } + DWORD fileAttributes = GetFileAttributesW(path); + memset(result, 0, sizeof(*result)); + if (fileAttributes != INVALID_FILE_ATTRIBUTES && + fileAttributes & FILE_ATTRIBUTE_DIRECTORY) { + /* \\.\pipe\ or \\.\mailslot\ */ + result->st_mode = _S_IFDIR; + } else if (fileType == FILE_TYPE_CHAR) { + /* \\.\nul */ + result->st_mode = _S_IFCHR; + } else if (fileType == FILE_TYPE_PIPE) { + /* \\.\pipe\spam */ + result->st_mode = _S_IFIFO; + } + /* FILE_TYPE_UNKNOWN, e.g. \\.\mailslot\waitfor.exe\spam */ + goto cleanup; + } + + /* Query the reparse tag, and traverse a non-link. */ + if (!traverse) { + if (!GetFileInformationByHandleEx(hFile, FileAttributeTagInfo, + &tagInfo, sizeof(tagInfo))) { + /* Allow devices that do not support FileAttributeTagInfo. */ + switch (GetLastError()) { + case ERROR_INVALID_PARAMETER: + case ERROR_INVALID_FUNCTION: + case ERROR_NOT_SUPPORTED: + tagInfo.FileAttributes = FILE_ATTRIBUTE_NORMAL; + tagInfo.ReparseTag = 0; + break; + default: + retval = -1; + goto cleanup; } + } else if (tagInfo.FileAttributes & + FILE_ATTRIBUTE_REPARSE_POINT) { + if (IsReparseTagNameSurrogate(tagInfo.ReparseTag)) { + if (isUnhandledTag) { + /* Traversing previously failed for either this link + or its target. */ + SetLastError(ERROR_CANT_ACCESS_FILE); + retval = -1; + goto cleanup; + } + /* Traverse a non-link, but not if traversing already failed + for an unhandled tag. */ + } else if (!isUnhandledTag) { + CloseHandle(hFile); + return win32_xstat_impl(path, result, TRUE); + } + } + } - code = win32_xstat_impl(target_path, result, FALSE); - PyMem_RawFree(target_path); - return code; + if (!GetFileInformationByHandle(hFile, &fileInfo)) { + switch (GetLastError()) { + case ERROR_INVALID_PARAMETER: + case ERROR_INVALID_FUNCTION: + case ERROR_NOT_SUPPORTED: + retval = -1; + goto cleanup; } - } else - CloseHandle(hFile); + /* Volumes and physical disks are block devices, e.g. + \\.\C: and \\.\PhysicalDrive0. */ + memset(result, 0, sizeof(*result)); + result->st_mode = 0x6000; /* S_IFBLK */ + goto cleanup; + } } - _Py_attribute_data_to_stat(&info, reparse_tag, result); - /* Set S_IEXEC if it is an .exe, .bat, ... */ - dot = wcsrchr(path, '.'); - if (dot) { - if (_wcsicmp(dot, L".bat") == 0 || _wcsicmp(dot, L".cmd") == 0 || - _wcsicmp(dot, L".exe") == 0 || _wcsicmp(dot, L".com") == 0) - result->st_mode |= 0111; + _Py_attribute_data_to_stat(&fileInfo, tagInfo.ReparseTag, result); + + if (!(fileInfo.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) { + /* Fix the file execute permissions. This hack sets S_IEXEC if + the filename has an extension that is commonly used by files + that CreateProcessW can execute. A real implementation calls + GetSecurityInfo, OpenThreadToken/OpenProcessToken, and + AccessCheck to check for generic read, write, and execute + access. */ + const wchar_t *fileExtension = wcsrchr(path, '.'); + if (fileExtension) { + if (_wcsicmp(fileExtension, L".exe") == 0 || + _wcsicmp(fileExtension, L".bat") == 0 || + _wcsicmp(fileExtension, L".cmd") == 0 || + _wcsicmp(fileExtension, L".com") == 0) { + result->st_mode |= 0111; + } + } } - return 0; + +cleanup: + if (hFile != INVALID_HANDLE_VALUE) { + CloseHandle(hFile); + } + + return retval; } static int @@ -1806,9 +1849,8 @@ win32_xstat(const wchar_t *path, struct _Py_stat_struct *result, BOOL traverse) default does not traverse symlinks and instead returns attributes for the symlink. - Therefore, win32_lstat will get the attributes traditionally, and - win32_stat will first explicitly resolve the symlink target and then will - call win32_lstat on that result. */ + Instead, we will open the file (which *does* traverse symlinks by default) + and GetFileInformationByHandle(). */ static int win32_lstat(const wchar_t* path, struct _Py_stat_struct *result) @@ -1877,6 +1919,9 @@ static PyStructSequence_Field stat_result_fields[] = { #ifdef HAVE_STRUCT_STAT_ST_FSTYPE {"st_fstype", "Type of filesystem"}, #endif +#ifdef HAVE_STRUCT_STAT_ST_REPARSE_TAG + {"st_reparse_tag", "Windows reparse tag"}, +#endif {0} }; @@ -1928,6 +1973,12 @@ static PyStructSequence_Field stat_result_fields[] = { #define ST_FSTYPE_IDX ST_FILE_ATTRIBUTES_IDX #endif +#ifdef HAVE_STRUCT_STAT_ST_REPARSE_TAG +#define ST_REPARSE_TAG_IDX (ST_FSTYPE_IDX+1) +#else +#define ST_REPARSE_TAG_IDX ST_FSTYPE_IDX +#endif + static PyStructSequence_Desc stat_result_desc = { "stat_result", /* name */ stat_result__doc__, /* doc */ @@ -2155,6 +2206,10 @@ _pystat_fromstructstat(STRUCT_STAT *st) PyStructSequence_SET_ITEM(v, ST_FSTYPE_IDX, PyUnicode_FromString(st->st_fstype)); #endif +#ifdef HAVE_STRUCT_STAT_ST_REPARSE_TAG + PyStructSequence_SET_ITEM(v, ST_REPARSE_TAG_IDX, + PyLong_FromUnsignedLong(st->st_reparse_tag)); +#endif if (PyErr_Occurred()) { Py_DECREF(v); @@ -3877,8 +3932,9 @@ os__getfinalpathname_impl(PyObject *module, path_t *path) } result = PyUnicode_FromWideChar(target_path, result_length); - if (path->narrow) + if (result && path->narrow) { Py_SETREF(result, PyUnicode_EncodeFSDefault(result)); + } cleanup: if (target_path != buf) { @@ -3888,44 +3944,6 @@ cleanup: return result; } -/*[clinic input] -os._isdir - - path as arg: object - / - -Return true if the pathname refers to an existing directory. -[clinic start generated code]*/ - -static PyObject * -os__isdir(PyObject *module, PyObject *arg) -/*[clinic end generated code: output=404f334d85d4bf25 input=36cb6785874d479e]*/ -{ - DWORD attributes; - path_t path = PATH_T_INITIALIZE("_isdir", "path", 0, 0); - - if (!path_converter(arg, &path)) { - if (PyErr_ExceptionMatches(PyExc_ValueError)) { - PyErr_Clear(); - Py_RETURN_FALSE; - } - return NULL; - } - - Py_BEGIN_ALLOW_THREADS - attributes = GetFileAttributesW(path.wide); - Py_END_ALLOW_THREADS - - path_cleanup(&path); - if (attributes == INVALID_FILE_ATTRIBUTES) - Py_RETURN_FALSE; - - if (attributes & FILE_ATTRIBUTE_DIRECTORY) - Py_RETURN_TRUE; - else - Py_RETURN_FALSE; -} - /*[clinic input] os._getvolumepathname @@ -7796,11 +7814,10 @@ os_readlink_impl(PyObject *module, path_t *path, int dir_fd) return PyBytes_FromStringAndSize(buffer, length); #elif defined(MS_WINDOWS) DWORD n_bytes_returned; - DWORD io_result; + DWORD io_result = 0; HANDLE reparse_point_handle; char target_buffer[_Py_MAXIMUM_REPARSE_DATA_BUFFER_SIZE]; _Py_REPARSE_DATA_BUFFER *rdb = (_Py_REPARSE_DATA_BUFFER *)target_buffer; - const wchar_t *print_name; PyObject *result; /* First get a handle to the reparse point */ @@ -7813,42 +7830,51 @@ os_readlink_impl(PyObject *module, path_t *path, int dir_fd) OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0); - Py_END_ALLOW_THREADS - - if (reparse_point_handle == INVALID_HANDLE_VALUE) { - return path_error(path); + if (reparse_point_handle != INVALID_HANDLE_VALUE) { + /* New call DeviceIoControl to read the reparse point */ + io_result = DeviceIoControl( + reparse_point_handle, + FSCTL_GET_REPARSE_POINT, + 0, 0, /* in buffer */ + target_buffer, sizeof(target_buffer), + &n_bytes_returned, + 0 /* we're not using OVERLAPPED_IO */ + ); + CloseHandle(reparse_point_handle); } - - Py_BEGIN_ALLOW_THREADS - /* New call DeviceIoControl to read the reparse point */ - io_result = DeviceIoControl( - reparse_point_handle, - FSCTL_GET_REPARSE_POINT, - 0, 0, /* in buffer */ - target_buffer, sizeof(target_buffer), - &n_bytes_returned, - 0 /* we're not using OVERLAPPED_IO */ - ); - CloseHandle(reparse_point_handle); Py_END_ALLOW_THREADS if (io_result == 0) { return path_error(path); } - if (rdb->ReparseTag != IO_REPARSE_TAG_SYMLINK) + wchar_t *name = NULL; + Py_ssize_t nameLen = 0; + if (rdb->ReparseTag == IO_REPARSE_TAG_SYMLINK) { - PyErr_SetString(PyExc_ValueError, - "not a symbolic link"); - return NULL; + name = (wchar_t *)((char*)rdb->SymbolicLinkReparseBuffer.PathBuffer + + rdb->SymbolicLinkReparseBuffer.SubstituteNameOffset); + nameLen = rdb->SymbolicLinkReparseBuffer.SubstituteNameLength / sizeof(wchar_t); } - print_name = (wchar_t *)((char*)rdb->SymbolicLinkReparseBuffer.PathBuffer + - rdb->SymbolicLinkReparseBuffer.PrintNameOffset); - - result = PyUnicode_FromWideChar(print_name, - rdb->SymbolicLinkReparseBuffer.PrintNameLength / sizeof(wchar_t)); - if (path->narrow) { - Py_SETREF(result, PyUnicode_EncodeFSDefault(result)); + else if (rdb->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT) + { + name = (wchar_t *)((char*)rdb->MountPointReparseBuffer.PathBuffer + + rdb->MountPointReparseBuffer.SubstituteNameOffset); + nameLen = rdb->MountPointReparseBuffer.SubstituteNameLength / sizeof(wchar_t); + } + else + { + PyErr_SetString(PyExc_ValueError, "not a symbolic link"); + } + if (name) { + if (nameLen > 4 && wcsncmp(name, L"\\??\\", 4) == 0) { + /* Our buffer is mutable, so this is okay */ + name[1] = L'\\'; + } + result = PyUnicode_FromWideChar(name, nameLen); + if (path->narrow) { + Py_SETREF(result, PyUnicode_EncodeFSDefault(result)); + } } return result; #endif @@ -13647,7 +13673,6 @@ static PyMethodDef posix_methods[] = { OS_PATHCONF_METHODDEF OS_ABORT_METHODDEF OS__GETFULLPATHNAME_METHODDEF - OS__ISDIR_METHODDEF OS__GETDISKUSAGE_METHODDEF OS__GETFINALPATHNAME_METHODDEF OS__GETVOLUMEPATHNAME_METHODDEF |