Function _is_loopback

app/main.py:303–308

(host: str | None)

def _is_loopback(host: str | None) -> bool:
    if not host:
        return False
    if host.startswith("::ffff:"):  # IPv4-mapped IPv6
        host = host[7:]
    return host in {"127.0.0.1", "::1", "localhost"} or host.startswith("127.")


@functools.lru_cache(maxsize=1)