[PATCH net-next v1 3/4] tools/net/ynl: Extend array-nest for multi level nesting

[Donald Hunter <donald.hunter@gmail.com>]

The nlctrl family uses 2 levels of array nesting for policy attributes.
Add a 'nest-depth' property to genetlink-legacy and extend ynl to use
it.

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
---
 Documentation/netlink/genetlink-legacy.yaml | 3 +++
 tools/net/ynl/lib/nlspec.py                 | 2 ++
 tools/net/ynl/lib/ynl.py                    | 9 ++++++---
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Documentation/netlink/genetlink-legacy.yaml b/Documentation/netlink/genetlink-legacy.yaml
index 938703088306..872c76065f1b 100644
--- a/Documentation/netlink/genetlink-legacy.yaml
+++ b/Documentation/netlink/genetlink-legacy.yaml
@@ -261,6 +261,9 @@ properties:
               struct:
                 description: Name of the struct type used for the attribute.
                 type: string
+              nest-depth:
+                description: Depth of nesting for an array-nest, defaults to 1.
+                type: integer
               # End genetlink-legacy
 
       # Make sure name-prefix does not appear in subsets (subsets inherit naming)
diff --git a/tools/net/ynl/lib/nlspec.py b/tools/net/ynl/lib/nlspec.py
index fbce52395b3b..50e8447f089a 100644
--- a/tools/net/ynl/lib/nlspec.py
+++ b/tools/net/ynl/lib/nlspec.py
@@ -161,6 +161,7 @@ class SpecAttr(SpecElement):
         sub_message   string, name of sub message type
         selector      string, name of attribute used to select
                       sub-message type
+        nest_depth    integer, depth of array nesting
 
         is_auto_scalar bool, attr is a variable-size scalar
     """
@@ -178,6 +179,7 @@ class SpecAttr(SpecElement):
         self.display_hint = yaml.get('display-hint')
         self.sub_message = yaml.get('sub-message')
         self.selector = yaml.get('selector')
+        self.nest_depth = yaml.get('nest-depth', 1)
 
         self.is_auto_scalar = self.type == "sint" or self.type == "uint"
 
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 29262505a3f2..efceea9433f2 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -556,14 +556,17 @@ class YnlFamily(SpecFamily):
                 decoded = self._formatted_string(decoded, attr_spec.display_hint)
         return decoded
 
-    def _decode_array_nest(self, attr, attr_spec):
+    def _decode_array_nest(self, attr, attr_spec, depth):
         decoded = []
         offset = 0
         while offset < len(attr.raw):
             item = NlAttr(attr.raw, offset)
             offset += item.full_len
 
-            subattrs = self._decode(NlAttrs(item.raw), attr_spec['nested-attributes'])
+            if depth > 1:
+                subattrs = self._decode_array_nest(item, attr_spec, depth - 1)
+            else:
+                subattrs = self._decode(NlAttrs(item.raw), attr_spec['nested-attributes'])
             decoded.append({ item.type: subattrs })
         return decoded
 
@@ -649,7 +652,7 @@ class YnlFamily(SpecFamily):
                 if 'enum' in attr_spec:
                     decoded = self._decode_enum(decoded, attr_spec)
             elif attr_spec["type"] == 'array-nest':
-                decoded = self._decode_array_nest(attr, attr_spec)
+                decoded = self._decode_array_nest(attr, attr_spec, attr_spec.nest_depth)
             elif attr_spec["type"] == 'bitfield32':
                 value, selector = struct.unpack("II", attr.raw)
                 if 'enum' in attr_spec:
-- 
2.42.0