[PATCH net-next 5/6] bridge: Add per-VLAN netlink handling for neigh_forward_grat

[Danielle Ratson]

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

Signed-off-by: Danielle Ratson <danieller@xxxxxxxxxx>
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
Reviewed-by: Petr Machata <petrm@xxxxxxxxxx>
---
 net/bridge/br_vlan.c         |  1 +
 net/bridge/br_vlan_options.c | 24 ++++++++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 84a180927eb7..5560afcaaca3 100644
--- 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 5514e1fc8d1f..92af1e558fda 100644
--- 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;
 }
 
-- 
2.51.0