tools: ynl-gen: split presence metadata

Each YNL struct contains the data and a sub-struct indicating which
fields are valid. Something like:

  struct family_op_req {
      struct {
            u32 a:1;
            u32 b:1;
	    u32 bin_len;
      } _present;

      u32 a;
      u64 b;
      const unsigned char *bin;
  };

Note that the bin object 'bin' has a length stored, and that length
has a _len suffix added to the field name. This breaks if there
is a explicit field called bin_len, which is the case for some
TC actions. Move the length fields out of the _present struct,
create a new struct called _len:

  struct family_op_req {
      struct {
            u32 a:1;
            u32 b:1;
      } _present;
      struct {
	    u32 bin;
      } _len;

      u32 a;
      u64 b;
      const unsigned char *bin;
  };

This should prevent name collisions and help with the packing
of the struct.

Unfortunately this is a breaking change, but hopefully the migration
isn't too painful.

Link: https://patch.msgid.link/20250505165208.248049-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/net/ynl/samples/rt-route.c b/tools/net/ynl/samples/rt-route.c
index 9d9c868f8873..7427104a96df 100644
--- a/tools/net/ynl/samples/rt-route.c
+++ b/tools/net/ynl/samples/rt-route.c
@@ -26,13 +26,13 @@ static void rt_route_print(struct rt_route_getroute_rsp *r)
 			printf("oif: %-16s ", name);
 	}
 
-	if (r->_present.dst_len) {
+	if (r->_len.dst) {
 		route = inet_ntop(r->_hdr.rtm_family, r->dst,
 				  route_str, sizeof(route_str));
 		printf("dst: %s/%d", route, r->_hdr.rtm_dst_len);
 	}
 
-	if (r->_present.gateway_len) {
+	if (r->_len.gateway) {
 		route = inet_ntop(r->_hdr.rtm_family, r->gateway,
 				  route_str, sizeof(route_str));
 		printf("gateway: %s ", route);