[patch net-next 07/13] tools: ynl: add support for list in nested attribute

[Jiri Pirko <jiri@resnulli.us>]

From: Jiri Pirko <jiri@nvidia.com>

Some nested attributes, like devlink-fmg, contain plain list of
attributes that may repeat. Current decode rsp implementation is
dictionary which causes duplicate attributes to be re-written.

To solve this, introduce "nested-list" flag for "nest" type which
indicates the _decode() function to use list instead of dictionary and
store each decoded attribute into this list as a separate dictionary.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 Documentation/netlink/genetlink-legacy.yaml |  3 +++
 tools/net/ynl/lib/ynl.py                    | 18 ++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/Documentation/netlink/genetlink-legacy.yaml b/Documentation/netlink/genetlink-legacy.yaml
index 77d89f81c71f..0e0ee3b4ff5f 100644
--- a/Documentation/netlink/genetlink-legacy.yaml
+++ b/Documentation/netlink/genetlink-legacy.yaml
@@ -220,6 +220,9 @@ properties:
               nested-attributes:
                 description: Name of the space (sub-space) used inside the attribute.
                 type: string
+              nested-list:
+                description: The nested attribute contains a list of attributes.
+                type: boolean
               enum:
                 description: Name of the enum type used for the attribute.
                 type: string
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 8591e6bfe40b..08fe27c8dec7 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -386,8 +386,12 @@ class SpaceAttrs:
     def lookup(self, name):
         for scope in self.scopes:
             if name in scope.spec:
-                if name in scope.values:
+                if isinstance(scope.values, dict) and name in scope.values:
                     return scope.values[name]
+                if isinstance(scope.values, list):
+                    for item in reversed(scope.values):
+                        if name in item:
+                            return item[name]
                 spec_name = scope.spec.yaml['name']
                 raise Exception(
                     f"No value for '{name}' in attribute space '{spec_name}'")
@@ -568,6 +572,10 @@ class YnlFamily(SpecFamily):
             return attr.as_bin()
 
     def _rsp_add(self, rsp, name, is_multi, decoded):
+        if isinstance(rsp, list):
+            rsp.append({name: decoded})
+            return
+
         if is_multi == None:
             if name in rsp and type(rsp[name]) is not list:
                 rsp[name] = [rsp[name]]
@@ -620,8 +628,8 @@ class YnlFamily(SpecFamily):
                 raise Exception(f"Unknown attribute-set '{attr_space}' when decoding '{attr_spec.name}'")
         return decoded
 
-    def _decode(self, attrs, space, outer_attrs = None):
-        rsp = dict()
+    def _decode(self, attrs, space, outer_attrs = None, to_list = False):
+        rsp = list() if to_list else dict()
         if space:
             attr_space = self.attr_sets[space]
             search_attrs = SpaceAttrs(attr_space, rsp, outer_attrs)
@@ -637,7 +645,9 @@ class YnlFamily(SpecFamily):
                 continue
 
             if attr_spec["type"] == 'nest':
-                subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs)
+                nested_list = attr_spec['nested-list'] if 'nested-list' in attr_spec else False
+                subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'],
+                                       search_attrs, to_list = nested_list)
                 decoded = subdict
             elif attr_spec["type"] == 'string':
                 decoded = attr.as_strz()
-- 
2.43.2