diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2024-03-29 11:16:51 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-04-02 18:01:58 -0700 |
| commit | d6d647d7ba6413148c3db2d48640986c8c1d7d08 (patch) | |
| tree | 6da345e3cdb8dc53f5d90bed51971a2028dfbe93 /tools/net | |
| parent | d88cabfd9abcd01c7729e5383919357da732ada9 (diff) | |
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: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240329181651.319326-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools/net')
| -rw-r--r-- | tools/net/ynl/lib/ynl.h | 12 | ||||
| -rw-r--r-- | tools/net/ynl/samples/netdev.c | 2 |
2 files changed, 14 insertions, 0 deletions
diff --git a/tools/net/ynl/lib/ynl.h b/tools/net/ynl/lib/ynl.h index 9842e85a8c57..eef7c6324ed4 100644 --- a/tools/net/ynl/lib/ynl.h +++ b/tools/net/ynl/lib/ynl.h @@ -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); diff --git a/tools/net/ynl/samples/netdev.c b/tools/net/ynl/samples/netdev.c index 591b90e21890..3e7b29bd55d5 100644 --- a/tools/net/ynl/samples/netdev.c +++ b/tools/net/ynl/samples/netdev.c @@ -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); |