Commit d6d647d7 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

tools: ynl: add ynl_dump_empty() helper 



Checking if dump is empty requires a couple of casts.
Add a convenient wrapper.

Add an example use in the netdev sample, loopback is always
present so an empty dump is an error.

Reviewed-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240329181651.319326-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent d88cabfd

tools/net/ynl/lib/ynl.h

+12 −0
Original line number Diff line number Diff line
@@ -91,6 +91,18 @@ void ynl_sock_destroy(struct ynl_sock *ys); 
	     !ynl_dump_obj_is_last(iter);				\

	     iter = ynl_dump_obj_next(iter))



/**

 * ynl_dump_empty() - does the dump have no entries

 * @dump: pointer to the dump list, as returned by a dump call

 *

 * Check if the dump is empty, i.e. contains no objects.

 * Dump calls return NULL on error, and terminator element if empty.

 */

static inline bool ynl_dump_empty(void *dump)

{

	return dump == (void *)YNL_LIST_END;

}



int ynl_subscribe(struct ynl_sock *ys, const char *grp_name);

int ynl_socket_get_fd(struct ynl_sock *ys);

int ynl_ntf_check(struct ynl_sock *ys);

tools/net/ynl/samples/netdev.c

+2 −0
Original line number Diff line number Diff line
@@ -100,6 +100,8 @@ int main(int argc, char **argv) 
		if (!devs)

			goto err_close;



		if (ynl_dump_empty(devs))

			fprintf(stderr, "Error: no devices reported\n");

		ynl_dump_foreach(devs, d)

			netdev_print_device(d, 0);

		netdev_dev_get_list_free(devs);