bridge: Add per-VLAN netlink handling for neigh_forward_grat

Add netlink handlers for the per-VLAN neigh_forward_grat option via
BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT attribute.

The per-VLAN option provides fine-grained control, allowing different
VLANs on the same port to have different gratuitous ARP/unsolicited NA
forwarding behavior.

This enables control via 'bridge' commands:
 # bridge vlan set dev eth0 vid 10 neigh_suppress on
 # bridge vlan set dev eth0 vid 10 neigh_forward_grat on

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260511065936.4173106-6-danieller@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 84a180927eb73b73c0ef1bb2c92a17c8c96ded59..5560afcaaca3273510d756a53399584baf0c64d4 100644 (file)
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -2176,6 +2176,7 @@ static const struct nla_policy br_vlan_db_policy[BRIDGE_VLANDB_ENTRY_MAX + 1] =
        [BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS]    = { .type = NLA_REJECT },
        [BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS]  = { .type = NLA_U32 },
        [BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS]    = NLA_POLICY_MAX(NLA_U8, 1),
+       [BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT] = NLA_POLICY_MAX(NLA_U8, 1),
 };
 
 static int br_vlan_rtm_process_one(struct net_device *dev,

diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c
index 5514e1fc8d1faf79b759285e0a2e7c6aea303d5f..92af1e558fda886301f167463ddf43f14afd2702 100644 (file)
--- a/net/bridge/br_vlan_options.c
+++ b/net/bridge/br_vlan_options.c
@@ -54,7 +54,8 @@ bool br_vlan_opts_eq_range(const struct net_bridge_vlan *v_curr,
 
        /* Check user-visible priv_flags that affect output */
        if ((v_curr->priv_flags ^ range_end->priv_flags) &
-           (BR_VLFLAG_NEIGH_SUPPRESS_ENABLED | BR_VLFLAG_MCAST_ENABLED))
+           (BR_VLFLAG_NEIGH_SUPPRESS_ENABLED | BR_VLFLAG_MCAST_ENABLED |
+            BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED))
                return false;
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
@@ -74,7 +75,9 @@ bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v,
        if (nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_STATE, br_vlan_get_state(v)) ||
            !__vlan_tun_put(skb, v) ||
            nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS,
-                      !!(v->priv_flags & BR_VLFLAG_NEIGH_SUPPRESS_ENABLED)))
+                      !!(v->priv_flags & BR_VLFLAG_NEIGH_SUPPRESS_ENABLED)) ||
+           nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT,
+                      !!(v->priv_flags & BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED)))
                return false;
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
@@ -103,6 +106,7 @@ size_t br_vlan_opts_nl_size(void)
               + nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS */
 #endif
               + nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS */
+              + nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT */
               + 0;
 }
 
@@ -277,6 +281,22 @@ static int br_vlan_process_one_opts(const struct net_bridge *br,
                }
        }
 
+       if (tb[BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT]) {
+               bool enabled = v->priv_flags & BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED;
+               bool val = nla_get_u8(tb[BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT]);
+
+               if (!p) {
+                       NL_SET_ERR_MSG_MOD(extack,
+                                          "Can't set neigh_forward_grat for non-port vlans");
+                       return -EINVAL;
+               }
+
+               if (val != enabled) {
+                       v->priv_flags ^= BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED;
+                       *changed = true;
+               }
+       }
+
        return 0;
 }