[PATCH net 1/2] tools: ynl-gen-c: handle classic notifications without a matching request

[Demos Ra via B4 Relay <devnull+demosthenes.ra.gmail.com@kernel.org>]

From: Demos Ra <demosthenes.ra@gmail.com>

For classic Netlink families the notification table in the generated
user code is indexed by the message type the kernel sends. Since
commit 49398830a4aa ("tools: ynl-gen: support CRUD-like notifications
for classic Netlink") ynl-gen writes each index as the name of the
request that has the same message type, and fails if no request has
it:

  $ ./tools/net/ynl/pyynl/ynl_gen_c.py --mode user --source \
        --spec Documentation/netlink/specs/rt-nexthop.yaml
  ...
      crud_op = ri.family.req_by_value[op.rsp_value]
  KeyError: 116

rt-nexthop's newnexthopbucket-ntf is the only such notification: the
kernel sends it as RTM_NEWNEXTHOPBUCKET (116), and no request uses
that message type.

When no request matches, write the message type as a number, as
put_op_name() already does for messages whose request and reply types
differ. The generated code for every spec in the tree is unchanged.

Signed-off-by: Demos Ra <demosthenes.ra@gmail.com>
---
 tools/net/ynl/pyynl/ynl_gen_c.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index 4aca51396a9e..a009a842fb36 100755
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py
@@ -3409,9 +3409,11 @@ def render_scoped_consts(family, cw, scope):
 def _render_user_ntf_entry(ri, op):
     if not ri.family.is_classic():
         ri.cw.block_start(line=f"[{op.enum_name}] = ")
-    else:
+    elif op.rsp_value in ri.family.req_by_value:
         crud_op = ri.family.req_by_value[op.rsp_value]
         ri.cw.block_start(line=f"[{crud_op.enum_name}] = ")
+    else:
+        ri.cw.block_start(line=f"[{op.rsp_value}] = ")
     ri.cw.p(f".alloc_sz\t= sizeof({type_name(ri, 'event')}),")
     ri.cw.p(f".cb\t\t= {op_prefix(ri, 'reply', deref=True)}_parse,")
     ri.cw.p(f".policy\t\t= &{ri.struct['reply'].render_name}_nest,")

-- 
2.53.0