From 25e37418c87249369fe546f2cb6af578c16b68b9 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 9 May 2025 08:42:13 -0700 Subject: [PATCH] tools: ynl-gen: support struct for binary attributes Support using a struct pointer for binary attrs. Len field is maintained because the structs may grow with newer kernel versions. Or, which matters more, be shorter if the binary is built against newer uAPI than kernel against which it's executed. Since we are storing a pointer to a struct type - always allocate at least the amount of memory needed by the struct per current uAPI headers (unused mem is zeroed). Technically users should check the length field but per modern ASAN checks storing a short object under a pointer seems like a bad idea. Signed-off-by: Jakub Kicinski Reviewed-by: Donald Hunter Link: https://patch.msgid.link/20250509154213.1747885-4-kuba@kernel.org Signed-off-by: Paolo Abeni --- tools/net/ynl/pyynl/ynl_gen_c.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py index 9a5c65966e9d..3b064c61a374 100755 --- a/tools/net/ynl/pyynl/ynl_gen_c.py +++ b/tools/net/ynl/pyynl/ynl_gen_c.py @@ -566,6 +566,23 @@ class TypeBinary(Type): f'memcpy({member}, {self.c_name}, {presence});'] +class TypeBinaryStruct(TypeBinary): + def struct_member(self, ri): + ri.cw.p(f'struct {c_lower(self.get("struct"))} *{self.c_name};') + + def _attr_get(self, ri, var): + struct_sz = 'sizeof(struct ' + c_lower(self.get("struct")) + ')' + len_mem = var + '->_' + self.presence_type() + '.' + self.c_name + return [f"{len_mem} = len;", + f"if (len < {struct_sz})", + f"{var}->{self.c_name} = calloc(1, {struct_sz});", + "else", + f"{var}->{self.c_name} = malloc(len);", + f"memcpy({var}->{self.c_name}, ynl_attr_data(attr), len);"], \ + ['len = ynl_attr_data_len(attr);'], \ + ['unsigned int len;'] + + class TypeBinaryScalarArray(TypeBinary): def arg_member(self, ri): return [f'__{self.get("sub-type")} *{self.c_name}', 'size_t count'] @@ -1010,7 +1027,9 @@ class AttrSet(SpecAttrSet): elif elem['type'] == 'string': t = TypeString(self.family, self, elem, value) elif elem['type'] == 'binary': - if elem.get('sub-type') in scalars: + if 'struct' in elem: + t = TypeBinaryStruct(self.family, self, elem, value) + elif elem.get('sub-type') in scalars: t = TypeBinaryScalarArray(self.family, self, elem, value) else: t = TypeBinary(self.family, self, elem, value) -- 2.50.1