tools: ynl-gen: array-nest: support binary array with exact-len

IPv6 addresses are expressed as binary arrays since we don't have u128.
Since they are not variable length, however, they are relatively
easy to represent as an array of known size.

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250429154704.2613851-11-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index a4e65da19696b6b8027f080a2c41bc88982ae3a7..2d185c7ea16c347ff72b514b7532c863847ea52b 100755 (executable)
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py
@@ -183,10 +183,10 @@ class Type(SpecAttr):
         raise Exception(f"Struct member not implemented for class type {self.type}")
 
     def struct_member(self, ri):
-        if self.is_multi_val():
-            ri.cw.p(f"unsigned int n_{self.c_name};")
         member = self._complex_member_type(ri)
         if member:
+            if self.is_multi_val():
+                ri.cw.p(f"unsigned int n_{self.c_name};")
             ptr = '*' if self.is_multi_val() else ''
             if self.is_recursive_for_op(ri):
                 ptr = '*'
@@ -728,12 +728,22 @@ class TypeArrayNest(Type):
         elif self.attr['sub-type'] in scalars:
             scalar_pfx = '__' if ri.ku_space == 'user' else ''
             return scalar_pfx + self.attr['sub-type']
+        elif self.attr['sub-type'] == 'binary' and 'exact-len' in self.checks:
+            return None  # use arg_member()
         else:
             raise Exception(f"Sub-type {self.attr['sub-type']} not supported yet")
 
+    def arg_member(self, ri):
+        if self.sub_type == 'binary' and 'exact-len' in self.checks:
+            return [f'unsigned char (*{self.c_name})[{self.checks["exact-len"]}]',
+                    f'unsigned int n_{self.c_name}']
+        return super().arg_member(ri)
+
     def _attr_typol(self):
         if self.attr['sub-type'] in scalars:
             return f'.type = YNL_PT_U{c_upper(self.sub_type[1:])}, '
+        elif self.attr['sub-type'] == 'binary' and 'exact-len' in self.checks:
+            return f'.type = YNL_PT_BINARY, .len = {self.checks["exact-len"]}, '
         else:
             return f'.type = YNL_PT_NEST, .nest = &{self.nested_render_name}_nest, '
 
@@ -754,6 +764,9 @@ class TypeArrayNest(Type):
             ri.cw.block_start(line=f'for (i = 0; i < {var}->n_{self.c_name}; i++)')
             ri.cw.p(f"ynl_attr_put_{put_type}(nlh, i, {var}->{self.c_name}[i]);")
             ri.cw.block_end()
+        elif self.sub_type == 'binary' and 'exact-len' in self.checks:
+            ri.cw.p(f'for (i = 0; i < {var}->n_{self.c_name}; i++)')
+            ri.cw.p(f"ynl_attr_put(nlh, i, {var}->{self.c_name}[i], {self.checks['exact-len']});")
         else:
             raise Exception(f"Put for ArrayNest sub-type {self.attr['sub-type']} not supported, yet")
         ri.cw.p('ynl_attr_nest_end(nlh, array);')
@@ -964,7 +977,7 @@ class AttrSet(SpecAttrSet):
         elif elem['type'] == 'nest':
             t = TypeNest(self.family, self, elem, value)
         elif elem['type'] == 'indexed-array' and 'sub-type' in elem:
-            if elem["sub-type"] in ['nest', 'u32']:
+            if elem["sub-type"] in ['binary', 'nest', 'u32']:
                 t = TypeArrayNest(self.family, self, elem, value)
             else:
                 raise Exception(f'new_attr: unsupported sub-type {elem["sub-type"]}')
@@ -1786,7 +1799,7 @@ def _multi_parse(ri, struct, init_lines, local_vars):
     needs_parg = False
     for arg, aspec in struct.member_list():
         if aspec['type'] == 'indexed-array' and 'sub-type' in aspec:
-            if aspec["sub-type"] == 'nest':
+            if aspec["sub-type"] in {'binary', 'nest'}:
                 local_vars.append(f'const struct nlattr *attr_{aspec.c_name};')
                 array_nests.add(arg)
             elif aspec['sub-type'] in scalars:
@@ -1859,6 +1872,9 @@ def _multi_parse(ri, struct, init_lines, local_vars):
             ri.cw.p('return YNL_PARSE_CB_ERROR;')
         elif aspec.sub_type in scalars:
             ri.cw.p(f"dst->{aspec.c_name}[i] = ynl_attr_get_{aspec.sub_type}(attr);")
+        elif aspec.sub_type == 'binary' and 'exact-len' in aspec.checks:
+            # Length is validated by typol
+            ri.cw.p(f'memcpy(dst->{aspec.c_name}[i], ynl_attr_data(attr), {aspec.checks["exact-len"]});')
         else:
             raise Exception(f"Nest parsing type not supported in {aspec['name']}")
         ri.cw.p('i++;')