[PATCH net-next v4 2/6] tools: ynl: convert enum selector to string for sub-message parsing
flat view
WARM2d
From: Hangbin Liu <hidden>
Date: 2026-10-08 08:24:25
Also in:
bpf, lkml
Subsystem:
networking [general], the rest, yaml netlink (ynl) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Donald Hunter
From: Hangbin Liu <redacted>
YNL sub-message parsing expects a string selector for strcmp(). So for
non-external enum selectors, convert the integer value to its string form
via the family's {enum}_str() helper. This enables correct decoding of
sub-messages keyed by enum values.
After the change, if there is no encap_type (e.g. previous ordering on
older kernels), or a new encap_type is missing from the spec file in
future kernel, the code will report "Sub-message key not set", the same
with string lookup fails. With the subsequent rt-route encap spec update,
the newly generated code will look like:
if (!dst->_present.encap_type)
return ynl_submsg_failed(yarg, "encap", "encap-type");
encap_type_str = rt_route_encap_type_str(dst->encap_type);
if (!encap_type_str)
return ynl_submsg_failed(yarg, "encap", "enum-lookup-failed");
if (rt_route_encap_data_parse(&parg, encap_type_str, attr))
return YNL_PARSE_CB_ERROR;
Signed-off-by: Hangbin Liu <redacted>
---
For sashiko:
1. For the extack error-walking path in ynl.c that doesn't handle
enum-keyed selectors. This series doesn't modify ynl.c, it changes
the code generator to emit the _str() conversion in generated parsing
code. The run time error-walking path is a separate concern.
Since rt-route encap is the first enum-keyed sub-message in the YNL
specs, this is a new limitation rather than a regression in existing
functionality. It can be addressed as a follow-up patch to ynl.c.
2. For the selector byte-order issue. This doesn't affect the current
series. The encap-type selector is type: u16 with no byte-order
specified (native order), so the raw value passed to _str() is already
host-order. nftables is in GENS_UNSUP today, so no in-tree generated
family hits this yet. We address this as a follow-up.
---
tools/net/ynl/pyynl/ynl_gen_c.py | 34 +++++++++++++++++++++++++++++-----
1 file changed, 29 insertions(+), 5 deletions(-)
diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index 15c79849c609..4aca51396a9e 100755
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py@@ -951,13 +951,31 @@ class TypeSubMessage(TypeNest): sel_var = f"_sel_{sel}" else: sel_var = f"{var}->{sel}" - get_lines = [f'if (!{sel_var})', - f'return ynl_submsg_failed(yarg, "{self.name}", "{selector}");', - f"if ({self.nested_render_name}_parse(&parg, {sel_var}, attr))", - "return YNL_PARSE_CB_ERROR;"] + + local_vars = None + + if self.selector.is_enum_val() and not self.selector.is_external(): + enum = self.family.consts[self.selector.get_enum_name()] + pres_var = f"{var}->_present.{sel}" + parse_sel = f"{sel}_str" + local_vars = [f'const char *{parse_sel};'] + + get_lines = [ + f'if (!{pres_var})', + f'return ynl_submsg_failed(yarg, "{self.name}", "{selector}");', + f'{parse_sel} = {enum.render_name}_str({sel_var});', + f'if (!{parse_sel})', + f'return ynl_submsg_failed(yarg, "{self.name}", "enum-lookup-failed");'] + else: + parse_sel = sel_var + get_lines = [f'if (!{parse_sel})', + f'return ynl_submsg_failed(yarg, "{self.name}", "{selector}");'] + + get_lines += [f"if ({self.nested_render_name}_parse(&parg, {parse_sel}, attr))", + "return YNL_PARSE_CB_ERROR;"] init_lines = [f"parg.rsp_policy = &{self.nested_render_name}_nest;", f"parg.data = &{var}->{self.c_name};"] - return get_lines, init_lines, None + return get_lines, init_lines, local_vars class Selector:
@@ -979,6 +997,12 @@ class Selector: def is_external(self): return self._external + def is_enum_val(self): + return self.get_enum_name() is not None + + def get_enum_name(self): + return self.attr and self.attr.attr.get("enum") + class Struct: def __init__(self, family, space_name, type_list=None, fixed_header=None,
--
2.55.0