[LEDE-DEV] [PATCH] umdns: Replace unnecessary memset calls with {}.

[Zefir Kurtisi]

On 11/07/2017 09:24 PM, Rosen Penev wrote:
> Less verbose
> 
> Signed-off-by: Rosen Penev <rosenp at gmail.com>
> ---
>  interface.c | 22 ++++++++--------------
>  1 file changed, 8 insertions(+), 14 deletions(-)
> 
> diff --git a/interface.c b/interface.c
> index 7f814d2..18dee52 100644
> --- a/interface.c
> +++ b/interface.c
> @@ -44,7 +44,7 @@
>  static int
>  interface_send_packet4(struct interface *iface, struct sockaddr_in *to, struct iovec *iov, int iov_len)
>  {
> -	static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
> +	static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1] = {};
>  	static struct sockaddr_in a;
>  	static struct msghdr m = {
>  		.msg_name = (struct sockaddr *) &a,
> @@ -61,7 +61,6 @@ interface_send_packet4(struct interface *iface, struct sockaddr_in *to, struct i
>  	m.msg_iov = iov;
>  	m.msg_iovlen = iov_len;
>  
> -	memset(cmsg_data, 0, sizeof(cmsg_data));
>  	cmsg = CMSG_FIRSTHDR(&m);
>  	cmsg->cmsg_len = m.msg_controllen;
>  	cmsg->cmsg_level = IPPROTO_IP;

This one looks like a pitfall to me, since without the memset cmsg_data being
static is never zeroed again at runtime. Not sure if all cmsg members are
initialized after the removed memset, otherwise the change is wrong.


Cheers,
Zefir