Re: [PATCH] Generate netlink notification when default IPv6 route preference changes

[David Ahern]

On 2/9/22 12:38 PM, Kalash Nainwal wrote:
> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
> index f03b597e4121..fd14f5b1c767 100644
> --- a/net/ipv6/ndisc.c
> +++ b/net/ipv6/ndisc.c
> @@ -1337,8 +1337,12 @@ static void ndisc_router_discovery(struct sk_buff *skb)
>  			return;
>  		}
>  		neigh->flags |= NTF_ROUTER;
> -	} else if (rt) {
> +	} else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
> +		struct nl_info nlinfo = {
> +			.nl_net = net,
> +		};
>  		rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
> +		inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_CREATE);
>  	}
>  
>  	if (rt)

route exists, but the flags are updated so that should be NLM_F_REPLACE.