tools: ynl-gen: support limits using definitions

Support using defines / constants in integer checks.
Carolina will need this for rate API extensions.

Reported-by: Carolina Jubran <cjubran@nvidia.com>
Link: https://lore.kernel.org/1e886aaf-e1eb-4f1a-b7ef-f63b350a3320@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250203215510.1288728-2-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Documentation/netlink/genetlink-c.yaml

@@ -14,9 +14,10 @@ $defs:
     pattern: ^[0-9A-Za-z_-]+( - 1)?$
     minimum: 0
   len-or-limit:
-    # literal int or limit based on fixed-width type e.g. u8-min, u16-max, etc.
+    # literal int, const name, or limit based on fixed-width type
+    # e.g. u8-min, u16-max, etc.
     type: [ string, integer ]
-    pattern: ^[su](8|16|32|64)-(min|max)$
+    pattern: ^[0-9A-Za-z_-]+$
     minimum: 0
 
 # Schema for specs

Documentation/netlink/genetlink-legacy.yaml

@@ -14,9 +14,10 @@ $defs:
     pattern: ^[0-9A-Za-z_-]+( - 1)?$
     minimum: 0
   len-or-limit:
-    # literal int or limit based on fixed-width type e.g. u8-min, u16-max, etc.
+    # literal int, const name, or limit based on fixed-width type
+    # e.g. u8-min, u16-max, etc.
     type: [ string, integer ]
-    pattern: ^[su](8|16|32|64)-(min|max)$
+    pattern: ^[0-9A-Za-z_-]+$
     minimum: 0
 
 # Schema for specs

Documentation/netlink/genetlink.yaml

@@ -14,9 +14,10 @@ $defs:
     pattern: ^[0-9A-Za-z_-]+( - 1)?$
     minimum: 0
   len-or-limit:
-    # literal int or limit based on fixed-width type e.g. u8-min, u16-max, etc.
+    # literal int, const name, or limit based on fixed-width type
+    # e.g. u8-min, u16-max, etc.
     type: [ string, integer ]
-    pattern: ^[su](8|16|32|64)-(min|max)$
+    pattern: ^[0-9A-Za-z_-]+$
     minimum: 0
 
 # Schema for specs

tools/net/ynl/pyynl/ynl_gen_c.py

@@ -100,7 +100,7 @@ def get_limit(self, limit, default=None):
         if isinstance(value, int):
             return value
         if value in self.family.consts:
-            raise Exception("Resolving family constants not implemented, yet")
+            return self.family.consts[value]["value"]
         return limit_to_number(value)
 
     def get_limit_str(self, limit, default=None, suffix=''):
@@ -110,6 +110,9 @@ def get_limit_str(self, limit, default=None, suffix=''):
         if isinstance(value, int):
             return str(value) + suffix
         if value in self.family.consts:
+            const = self.family.consts[value]
+            if const.get('header'):
+                return c_upper(value)
             return c_upper(f"{self.family['name']}-{value}")
         return c_upper(value)