Re: [PATCH BlueZ] mesh: Fix long MIC usage in segmented messages

["Gix, Brian" <brian.gix@intel.com>]

Patch Applied

On Thu, 2019-05-23 at 10:53 -0700, Brian Gix wrote:
> From: Jakub Witowski <jakub.witowski@silvair.com>
> 
> Contrary to the comment, implementation used a 8-byte MIC even if this
> generated an additional segment.
> ---
>  mesh/model.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/mesh/model.c b/mesh/model.c
> index 034d54496..90bb62db8 100644
> --- a/mesh/model.c
> +++ b/mesh/model.c
> @@ -40,6 +40,9 @@
>  #include "mesh/util.h"
>  #include "mesh/model.h"
>  
> +/* Divide and round to ceiling (up) to calculate segment count */
> +#define CEILDIV(val, div) (((val) + (div) - 1) / (div))
> +
>  struct mesh_model {
>  	const struct mesh_model_ops *cbs;
>  	void *user_data;
> @@ -451,7 +454,7 @@ static bool msg_send(struct mesh_node *node, bool credential, uint16_t src,
>  
>  	/* Use large MIC if it doesn't affect segmentation */
>  	if (msg_len > 11 && msg_len <= 376) {
> -		if ((out_len / 12) == ((out_len + 4) / 12)) {
> +		if (CEILDIV(out_len, 12) == CEILDIV(out_len + 4, 12)) {
>  			szmic = true;
>  			out_len = msg_len + sizeof(uint64_t);
>  		}