diff --git a/litellm/proxy/guardrails/guardrail_hooks/custom_code/sandbox.py b/litellm/proxy/guardrails/guardrail_hooks/custom_code/sandbox.py index d5707894a9d..a1f291c0bbc 100644 --- a/litellm/proxy/guardrails/guardrail_hooks/custom_code/sandbox.py +++ b/litellm/proxy/guardrails/guardrail_hooks/custom_code/sandbox.py @@ -16,7 +16,7 @@ restriction intact. import ast import operator -from collections.abc import Callable, Mapping +from collections.abc import AsyncIterable, AsyncIterator, Callable, Mapping from types import CodeType from typing import Final @@ -48,15 +48,19 @@ class AsyncAwareTransformer(RestrictingNodeTransformer): inherited automatically. ``AsyncWith`` gets the same treatment for the same reason: ``node_contents_visit`` only recurses into children, so routing it there left ``async with x as (a, b)`` without the unpack guard that - ``with x as (a, b)`` gets. ``AsyncFor``/``Await`` delegate to - ``node_contents_visit`` so their children still get transformed. + ``with x as (a, b)`` gets. ``AsyncFor`` likewise delegates to ``visit_For``, + which is what wraps the loop iterator in ``_getiter_``. ``Await`` has no + synchronous counterpart and only wraps an expression, so it stays on + ``node_contents_visit``. """ def visit_AsyncFunctionDef(self, node: ast.AsyncFunctionDef) -> ast.AST: return self.visit_FunctionDef(node) def visit_AsyncFor(self, node: ast.AsyncFor) -> ast.AST: - return self.node_contents_visit(node) + transformed: Final = self.visit_For(node) + _use_async_iter_unpack(transformed) + return transformed def visit_AsyncWith(self, node: ast.AsyncWith) -> ast.AST: return self.visit_With(node) @@ -65,6 +69,39 @@ class AsyncAwareTransformer(RestrictingNodeTransformer): return self.node_contents_visit(node) +_ITER_UNPACK_NAME: Final = "_iter_unpack_sequence_" +_ASYNC_ITER_UNPACK_NAME: Final = "_aiter_unpack_sequence_" + + +def _use_async_iter_unpack(node: ast.AST) -> None: + """Point a transformed ``async for`` at the async unpack guard. + + ``visit_For`` rewrites ``for a, b in x`` into + ``for (a, b) in _iter_unpack_sequence_(x, spec, _getiter_)``. That helper is + a plain generator, which ``async for`` cannot consume, so the async form + needs the async-generator equivalent under its own name. + """ + iter_node: Final = getattr(node, "iter", None) + if ( + isinstance(iter_node, ast.Call) + and isinstance(iter_node.func, ast.Name) + and iter_node.func.id == _ITER_UNPACK_NAME + ): + iter_node.func.id = _ASYNC_ITER_UNPACK_NAME + + +async def _aiter_unpack_sequence_( + it: object, spec: object, _getiter_: Callable[[object], AsyncIterable[object]] +) -> AsyncIterator[object]: + """``guarded_iter_unpack_sequence`` for ``async for`` targets. + + Same contract as the RestrictedPython helper — guard the iteration, then + guard each element's sequence unpacking — over an async iterator. + """ + async for ob in _getiter_(it): + yield guarded_unpack_sequence(ob, spec, _getiter_) + + _INPLACE_OPS: Final[Mapping[str, Callable[[object, object], object]]] = { "+=": operator.iadd, "-=": operator.isub, @@ -125,6 +162,7 @@ def build_sandbox_globals() -> dict[str, object]: # ships no default. Without it those statements compile and then raise # NameError the first time the guardrail runs. "_unpack_sequence_": guarded_unpack_sequence, + _ASYNC_ITER_UNPACK_NAME: _aiter_unpack_sequence_, "_write_": full_write_guard, "_inplacevar_": _inplacevar_, } diff --git a/tests/test_litellm/proxy/guardrails/test_custom_code_security.py b/tests/test_litellm/proxy/guardrails/test_custom_code_security.py index 679c0966828..91bd61f8686 100644 --- a/tests/test_litellm/proxy/guardrails/test_custom_code_security.py +++ b/tests/test_litellm/proxy/guardrails/test_custom_code_security.py @@ -311,3 +311,56 @@ async def test_async_with_still_executes(): sandbox_globals, ) assert await sandbox_globals["f"](_ACtx((5, 6))) == 11 + + +def test_async_for_gets_the_same_guards_as_for(): + """`async for` is the async spelling of `for`; it must not enforce less.""" + sync_guards = _guard_names("def f(x):\n for a in x:\n pass\n") + async_guards = _guard_names("async def f(x):\n async for a in x:\n pass\n") + + assert "_getiter_" in sync_guards, "precondition: `for` iteration is guarded" + assert sync_guards <= async_guards + + +def test_async_for_unpacking_uses_the_async_unpack_guard(): + """Tuple targets are guarded too, via the async-iterable variant of the helper.""" + guards = _guard_names("async def f(x):\n async for a, b in x:\n pass\n") + + assert "_aiter_unpack_sequence_" in guards + # The sync generator would raise "requires an object with __aiter__". + assert "_iter_unpack_sequence_" not in guards + + +@pytest.mark.asyncio +@pytest.mark.parametrize( + ("body", "items", "expected"), + [ + (" async for i in src:\n out.append(i)\n", [1, 2, 3], [1, 2, 3]), + (" async for a, b in src:\n out.append(a + b)\n", [(1, 2), (3, 4)], [3, 7]), + ], +) +async def test_async_for_still_executes(body: str, items: list, expected: list): + """Guarding `async for` must not break it, with or without a tuple target.""" + from litellm.proxy.guardrails.guardrail_hooks.custom_code.sandbox import ( + build_sandbox_globals, + compile_sandboxed, + ) + + class _AIter: + def __init__(self, values): + self.values = list(values) + + def __aiter__(self): + return self + + async def __anext__(self): + if not self.values: + raise StopAsyncIteration + return self.values.pop(0) + + sandbox_globals = build_sandbox_globals() + exec( # noqa: S102 + compile_sandboxed("async def f(src):\n out = []\n" + body + " return out\n"), + sandbox_globals, + ) + assert await sandbox_globals["f"](_AIter(items)) == expected