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 <[email protected]>
Reviewed-by: Ido Schimmel <[email protected]>
Reviewed-by: Petr Machata <[email protected]>
---
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 <[email protected]>
