Function reject_symlink_components

src/storage.rs:559–590

(path: &Path, subject: &str)

}

fn reject_symlink_components(path: &Path, subject: &str) -> io::Result<()> {
    let mut current = PathBuf::new();
    let mut has_normal_component = false;
    for component in path.components() {
        match component {
            Component::Normal(_) => {
                current.push(component.as_os_str());
                has_normal_component = true;
            }
            Component::RootDir | Component::Prefix(_) => {
                current.push(component.as_os_str());
            }
            Component::CurDir | Component::ParentDir => {
                return Err(invalid_input(format!("{subject} path must be normalized")));
            }
        }
        if !has_normal_component {
            continue;
        }
        match fs::symlink_metadata(&current) {
            Ok(meta) if meta.file_type().is_symlink() => {
                return Err(invalid_input(format!(
                    "{subject} path must not contain symlinks"
                )));
            }
            Ok(_) => {}
            Err(err) if err.kind() == io::ErrorKind::NotFound => break,
            Err(err) => return Err(err),
        }
    }
    Ok(())
}

fn invalid_input(message: impl Into<String>) -> io::Error {
    io::Error::new(io::ErrorKind::InvalidInput, message.into())