Commit 25e37418 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Paolo Abeni
Browse files

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: default avatarJakub Kicinski <kuba@kernel.org>
Reviewed-by: default avatarDonald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250509154213.1747885-4-kuba@kernel.org


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 9ba8e351

tools/net/ynl/pyynl/ynl_gen_c.py

+20 −1
Original line number Diff line number Diff line
@@ -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)