Re: [PATCH net-next 4/6] bridge: Add port-level netlink handling for neigh_forward_grat

[Nikolay Aleksandrov <razor@blackwall.org>]

On 03/05/2026 10:35, Danielle Ratson wrote:
> Add netlink handlers for the port-level neigh_forward_grat option via
> IFLA_BRPORT_NEIGH_FORWARD_GRAT attribute.
> 
> The default value of OFF preserves existing behavior, i.e. gratuitous ARP
> and unsolicited NA are suppressed when neigh_suppress is enabled. Users can
> explicitly set it to ON to allow these packets through.
> 
> Example for enabling control via 'bridge link' command:
>   # bridge link set dev eth0 neigh_suppress on
>   # bridge link set dev eth0 neigh_forward_grat on
> 
> Signed-off-by: Danielle Ratson <danieller@nvidia.com>
> Reviewed-by: Ido Schimmel <idosch@nvidia.com>
> Reviewed-by: Petr Machata <petrm@nvidia.com>
> ---
>   net/bridge/br_netlink.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
> index 6fd5386a1d64..898326c201ef 100644
> --- a/net/bridge/br_netlink.c
> +++ b/net/bridge/br_netlink.c
> @@ -190,6 +190,7 @@ static inline size_t br_port_info_size(void)
>   		+ nla_total_size(1)	/* IFLA_BRPORT_LOCKED */
>   		+ nla_total_size(1)	/* IFLA_BRPORT_MAB */
>   		+ nla_total_size(1)	/* IFLA_BRPORT_NEIGH_VLAN_SUPPRESS */
> +		+ nla_total_size(1)	/* IFLA_BRPORT_NEIGH_FORWARD_GRAT */
>   		+ nla_total_size(sizeof(struct ifla_bridge_id))	/* IFLA_BRPORT_ROOT_ID */
>   		+ nla_total_size(sizeof(struct ifla_bridge_id))	/* IFLA_BRPORT_BRIDGE_ID */
>   		+ nla_total_size(sizeof(u16))	/* IFLA_BRPORT_DESIGNATED_PORT */
> @@ -282,7 +283,9 @@ static int br_port_fill_attrs(struct sk_buff *skb,
>   	    nla_put_u8(skb, IFLA_BRPORT_LOCKED, !!(p->flags & BR_PORT_LOCKED)) ||
>   	    nla_put_u8(skb, IFLA_BRPORT_MAB, !!(p->flags & BR_PORT_MAB)) ||
>   	    nla_put_u8(skb, IFLA_BRPORT_NEIGH_VLAN_SUPPRESS,
> -		       !!(p->flags & BR_NEIGH_VLAN_SUPPRESS)))
> +		       !!(p->flags & BR_NEIGH_VLAN_SUPPRESS)) ||
> +	    nla_put_u8(skb, IFLA_BRPORT_NEIGH_FORWARD_GRAT,
> +		       !!(p->flags & BR_NEIGH_FORWARD_GRAT)))
>   		return -EMSGSIZE;
>   
>   	timerval = br_timer_value(&p->message_age_timer);
> @@ -902,6 +905,7 @@ static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = {
>   	[IFLA_BRPORT_MCAST_MAX_GROUPS] = { .type = NLA_U32 },
>   	[IFLA_BRPORT_NEIGH_VLAN_SUPPRESS] = NLA_POLICY_MAX(NLA_U8, 1),
>   	[IFLA_BRPORT_BACKUP_NHID] = { .type = NLA_U32 },
> +	[IFLA_BRPORT_NEIGH_FORWARD_GRAT] = NLA_POLICY_MAX(NLA_U8, 1),
>   };
>   
>   /* Change the state of the port and notify spanning tree */
> @@ -970,6 +974,8 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[],
>   	br_set_port_flag(p, tb, IFLA_BRPORT_MAB, BR_PORT_MAB);
>   	br_set_port_flag(p, tb, IFLA_BRPORT_NEIGH_VLAN_SUPPRESS,
>   			 BR_NEIGH_VLAN_SUPPRESS);
> +	br_set_port_flag(p, tb, IFLA_BRPORT_NEIGH_FORWARD_GRAT,
> +			 BR_NEIGH_FORWARD_GRAT);
>   
>   	if ((p->flags & BR_PORT_MAB) &&
>   	    (!(p->flags & BR_PORT_LOCKED) || !(p->flags & BR_LEARNING))) {

Acked-by: Nikolay Aleksandrov <razor@blackwall.org>