tools/net/ynl: Fix extack decoding for directional ops

NetlinkProtocol.decode() was looking up ops by response value which breaks
when it is used for extack decoding of directional ops. Instead, pass
the op to decode().
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240418104737.77914-3-donald.hunter@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/net/ynl/lib/ynl.py

@@ -386,12 +386,9 @@ class NetlinkProtocol:
     def _decode(self, nl_msg):
         return nl_msg
 
-    def decode(self, ynl, nl_msg):
+    def decode(self, ynl, nl_msg, op):
         msg = self._decode(nl_msg)
-        fixed_header_size = 0
-        if ynl:
-            op = ynl.rsp_by_value[msg.cmd()]
-            fixed_header_size = ynl._struct_size(op.fixed_header)
+        fixed_header_size = ynl._struct_size(op.fixed_header)
         msg.raw_attrs = NlAttrs(msg.raw, fixed_header_size)
         return msg
 
@@ -797,7 +794,7 @@ class YnlFamily(SpecFamily):
         if 'bad-attr-offs' not in extack:
             return
 
-        msg = self.nlproto.decode(self, NlMsg(request, 0, op.attr_set))
+        msg = self.nlproto.decode(self, NlMsg(request, 0, op.attr_set), op)
         offset = self.nlproto.msghdr_size() + self._struct_size(op.fixed_header)
         path = self._decode_extack_path(msg.raw_attrs, op.attr_set, offset,
                                         extack['bad-attr-offs'])
@@ -922,7 +919,8 @@ class YnlFamily(SpecFamily):
                     print("Netlink done while checking for ntf!?")
                     continue
 
-                decoded = self.nlproto.decode(self, nl_msg)
+                op = self.rsp_by_value[nl_msg.cmd()]
+                decoded = self.nlproto.decode(self, nl_msg, op)
                 if decoded.cmd() not in self.async_msg_ids:
                     print("Unexpected msg id done while checking for ntf", decoded)
                     continue
@@ -979,7 +977,7 @@ class YnlFamily(SpecFamily):
                     done = True
                     break
 
-                decoded = self.nlproto.decode(self, nl_msg)
+                decoded = self.nlproto.decode(self, nl_msg, op)
 
                 # Check if this is a reply to our request
                 if nl_msg.nl_seq != req_seq or decoded.cmd() != op.rsp_value: