72 lines
2.3 KiB
Python
72 lines
2.3 KiB
Python
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"""Internal directory binding helpers for disposable publication paths."""
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from __future__ import annotations
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import os
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import stat
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from pathlib import Path
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from .errors import DocForgeError
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def open_bound_directory(path: Path) -> int:
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"""Open one real directory and bind its current inode for later operations."""
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try:
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path_status = path.lstat()
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if (
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stat.S_ISLNK(path_status.st_mode)
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or not stat.S_ISDIR(path_status.st_mode)
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or path.resolve(strict=True) != path
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):
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raise DocForgeError(
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"path_escape",
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"Derived cache root is not a safe real directory",
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)
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directory_fd = os.open(path, os.O_RDONLY | os.O_DIRECTORY | os.O_NOFOLLOW)
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except FileNotFoundError as error:
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raise DocForgeError(
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"missing_index",
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"Derived cache root does not exist",
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) from error
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except OSError as error:
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raise DocForgeError(
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"path_escape",
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"Derived cache root cannot be opened safely",
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) from error
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try:
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opened_status = os.fstat(directory_fd)
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if opened_status.st_dev != path_status.st_dev or opened_status.st_ino != path_status.st_ino:
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raise DocForgeError(
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"path_escape",
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"Derived cache root changed while opening",
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)
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except Exception:
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os.close(directory_fd)
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raise
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return directory_fd
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def require_bound_directory(path: Path, directory_fd: int) -> None:
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"""Require a path to still name the exact opened real directory."""
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try:
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path_status = path.lstat()
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opened_status = os.fstat(directory_fd)
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if (
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stat.S_ISLNK(path_status.st_mode)
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or not stat.S_ISDIR(path_status.st_mode)
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or path.resolve(strict=True) != path
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or opened_status.st_dev != path_status.st_dev
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or opened_status.st_ino != path_status.st_ino
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):
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raise DocForgeError(
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"path_escape",
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"Derived cache root changed during publication",
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)
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except FileNotFoundError as error:
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raise DocForgeError(
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"path_escape",
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"Derived cache root disappeared during publication",
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) from error
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