ubus: fix GCC strncpy() truncation warning

When building with gcc-10 and -O2, the following warning in ubus.c is
triggered during the compilation:

    In function ‘uc_ubus_object_register’,
        inlined from ‘uc_ubus_publish’ at .../ubus.c:1521:10:
    .../ubus.c:1464:14: error: ‘strncpy’ output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation]
     1464 |  obj->name = strncpy(onptr, ubus_object_name, namelen);
          |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    .../ubus.c: In function ‘uc_ubus_publish’:
    .../ubus.c:1447:12: note: length computed here
     1447 |  namelen = strlen(ubus_object_name);
          |            ^~~~~~~~~~~~~~~~~~~~~~~~
    cc1: all warnings being treated as errors

Solve this issue by using memcpy() instead. We already take care of
allocating a zeroed, strlen() + 1 sized destination buffer so loosing
the `\0` byte of the source string is perfectly fine.

Fixes: #100
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/ubus.c b/lib/ubus.c
index 7f30fb8..4766119 100644
--- a/lib/ubus.c
+++ b/lib/ubus.c
@@ -1461,7 +1461,7 @@ uc_ubus_object_register(struct ubus_context *ctx, const char *ubus_object_name,
 	method = (struct ubus_method *)mptr;
 
 	obj = &uuobj->obj;
-	obj->name = strncpy(onptr, ubus_object_name, namelen);
+	obj->name = memcpy(onptr, ubus_object_name, namelen);
 	obj->methods = method;
 
 	if (ubus_object_methods) {