Subject: Re: Removing GENL_ID_GENERATE breaks userspace API

From: Johannes Berg <[email-masked]>
Date: Thu, 02 Mar 2017 19:11:22 +0100

On Thu, 2017-03-02 at 17:50 +0100, Marcel Holtmann wrote:
> Hi Johannes,
> 
> you have removed GENL_ID_GENERATE in 4.10, but that is actually
> breaking userspace API.
> 
> commit a07ea4d9941af5a0c6f0be2a71b51ac9c083c5e5
> Author: Johannes Berg <[email-masked]>
> Date:   Mon Oct 24 14:40:02 2016 +0200
> 
>     genetlink: no longer support using static family IDs
> 
> diff --git a/include/uapi/linux/genetlink.h
> b/include/uapi/linux/genetlink.h
> index 5512c90af7e3..d9b2db4a29c6 100644
> --- a/include/uapi/linux/genetlink.h
> +++ b/include/uapi/linux/genetlink.h
> @@ -26,7 +26,6 @@ struct genlmsghdr {
>  /*
>   * List of reserved static generic netlink identifiers:
>   */
> -#define GENL_ID_GENERATE       0
>  #define GENL_ID_CTRL           NLMSG_MIN_TYPE
> 
> Since the GENL_ID_GENERATE is in include/uapi/ I would have expected
> that you leave this in. For us, you just broke userspace API with
> this change.

Huh. It makes no sense to be using it nor ever did, but I guess we can
add it back with a comment saying that it's actually needed - send a
patch?

johannes