Re: [PATCH] netlink: Drop nexthop state flags from routes we duplicate

[Paul Holzinger <pholzing@redhat.com>]

On 18/09/2025 18:33, Stefano Brivio wrote:
> The kernel doesn't like those (EINVAL) on RTM_NEWROUTE, as they are
> flags representing states, not configuration.
>
> Link: https://github.com/containers/podman/discussions/27104
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Paul Holzinger <pholzing@redhat.com>
> ---
>   netlink.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/netlink.c b/netlink.c
> index 8f82e73..c436780 100644
> --- a/netlink.c
> +++ b/netlink.c
> @@ -565,6 +565,11 @@ int nl_route_dup(int s_src, unsigned int ifi_src,
>   		if (nh->nlmsg_type != RTM_NEWROUTE)
>   			continue;
>   
> +		/* nexthop state flags don't apply to freshly created routes,
> +		 * and the kernel will refuse our route if they are set.
> +		 */
> +		rtm->rtm_flags &= ~RTNH_COMPARE_MASK;
> +
>   		for (rta = RTM_RTA(rtm), na = RTM_PAYLOAD(nh); RTA_OK(rta, na);
>   		     rta = RTA_NEXT(rta, na)) {
>   			/* RTA_OIF and RTA_MULTIPATH attributes carry the

-- 
Paul Holzinger