[Patch net-next 2/3] net: bridge: mcast: Notify on offload flag change

[Joseph Huang]

Notify user space on offload flag(s) change.

This behavior is controlled by the new knob mdb_notify_on_flag_change:

0 - the bridge will not notify user space about MDB flag change
1 - the bridge will notify user space about flag change if either
    MDB_PG_FLAGS_OFFLOAD or MDB_PG_FLAGS_OFFLOAD_FAILED has changed
2 - the bridge will notify user space about flag change only if
    MDB_PG_FLAGS_OFFLOAD_FAILED has changed

The default value is 0.

Signed-off-by: Joseph Huang <Joseph.Huang@xxxxxxxxxx>
---
 net/bridge/br_mdb.c       | 28 +++++++++++++++++++++++-----
 net/bridge/br_multicast.c | 25 +++++++++++++++++++++++++
 net/bridge/br_private.h   | 15 +++++++++++++++
 net/bridge/br_switchdev.c | 25 +++++++++++++++++++++++--
 4 files changed, 86 insertions(+), 7 deletions(-)

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 0639691cd19b..d206b5a160f3 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -519,16 +519,17 @@ static size_t rtnl_mdb_nlmsg_size(const struct net_bridge_port_group *pg)
 	       rtnl_mdb_nlmsg_pg_size(pg);
 }
 
-void br_mdb_notify(struct net_device *dev,
-		   struct net_bridge_mdb_entry *mp,
-		   struct net_bridge_port_group *pg,
-		   int type)
+static void _br_mdb_notify(struct net_device *dev,
+			   struct net_bridge_mdb_entry *mp,
+			   struct net_bridge_port_group *pg,
+			   int type, bool notify_switchdev)
 {
 	struct net *net = dev_net(dev);
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
 
-	br_switchdev_mdb_notify(dev, mp, pg, type);
+	if (notify_switchdev)
+		br_switchdev_mdb_notify(dev, mp, pg, type);
 
 	skb = nlmsg_new(rtnl_mdb_nlmsg_size(pg), GFP_ATOMIC);
 	if (!skb)
@@ -546,6 +547,23 @@ void br_mdb_notify(struct net_device *dev,
 	rtnl_set_sk_err(net, RTNLGRP_MDB, err);
 }
 
+void br_mdb_notify(struct net_device *dev,
+		   struct net_bridge_mdb_entry *mp,
+		   struct net_bridge_port_group *pg,
+		   int type)
+{
+	_br_mdb_notify(dev, mp, pg, type, true);
+}
+
+#ifdef CONFIG_NET_SWITCHDEV
+void br_mdb_flag_change_notify(struct net_device *dev,
+			       struct net_bridge_mdb_entry *mp,
+			       struct net_bridge_port_group *pg)
+{
+	_br_mdb_notify(dev, mp, pg, RTM_NEWMDB, false);
+}
+#endif
+
 static int nlmsg_populate_rtr_fill(struct sk_buff *skb,
 				   struct net_device *dev,
 				   int ifindex, u16 vid, u32 pid,
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index b2ae0d2434d2..8d583caecd40 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -4051,6 +4051,10 @@ void br_multicast_ctx_init(struct net_bridge *br,
 	brmctx->ip6_querier.port_ifidx = 0;
 	seqcount_spinlock_init(&brmctx->ip6_querier.seq, &br->multicast_lock);
 #endif
+#ifdef CONFIG_NET_SWITCHDEV
+	brmctx->multicast_mdb_notify_on_flag_change =
+		MDB_NOTIFY_ON_FLAG_CHANGE_DISABLE;
+#endif
 
 	timer_setup(&brmctx->ip4_mc_router_timer,
 		    br_ip4_multicast_local_router_expired, 0);
@@ -4708,6 +4712,27 @@ int br_multicast_set_mld_version(struct net_bridge_mcast *brmctx,
 }
 #endif
 
+#ifdef CONFIG_NET_SWITCHDEV
+int br_multicast_set_mdb_notify_on_flag_change(struct net_bridge_mcast *brmctx,
+					       u8 val)
+{
+	switch (val) {
+	case MDB_NOTIFY_ON_FLAG_CHANGE_DISABLE:
+	case MDB_NOTIFY_ON_FLAG_CHANGE_BOTH:
+	case MDB_NOTIFY_ON_FLAG_CHANGE_FAIL_ONLY:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	spin_lock_bh(&brmctx->br->multicast_lock);
+	brmctx->multicast_mdb_notify_on_flag_change = val;
+	spin_unlock_bh(&brmctx->br->multicast_lock);
+
+	return 0;
+}
+#endif
+
 void br_multicast_set_query_intvl(struct net_bridge_mcast *brmctx,
 				  unsigned long val)
 {
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index cd6b4e91e7d6..8e8de5d54ae3 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -132,6 +132,10 @@ struct net_bridge_mcast_port {
 #endif /* CONFIG_BRIDGE_IGMP_SNOOPING */
 };
 
+#define MDB_NOTIFY_ON_FLAG_CHANGE_DISABLE	0
+#define MDB_NOTIFY_ON_FLAG_CHANGE_BOTH		1
+#define MDB_NOTIFY_ON_FLAG_CHANGE_FAIL_ONLY	2
+
 /* net_bridge_mcast must be always defined due to forwarding stubs */
 struct net_bridge_mcast {
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
@@ -146,6 +150,9 @@ struct net_bridge_mcast {
 	u8				multicast_router;
 #if IS_ENABLED(CONFIG_IPV6)
 	u8				multicast_mld_version;
+#endif
+#ifdef CONFIG_NET_SWITCHDEV
+	u8				multicast_mdb_notify_on_flag_change;
 #endif
 	unsigned long			multicast_last_member_interval;
 	unsigned long			multicast_membership_interval;
@@ -988,6 +995,10 @@ int br_multicast_set_igmp_version(struct net_bridge_mcast *brmctx,
 int br_multicast_set_mld_version(struct net_bridge_mcast *brmctx,
 				 unsigned long val);
 #endif
+#ifdef CONFIG_NET_SWITCHDEV
+int br_multicast_set_mdb_notify_on_flag_change(struct net_bridge_mcast *brmctx,
+					       u8 val);
+#endif
 struct net_bridge_mdb_entry *
 br_mdb_ip_get(struct net_bridge *br, struct br_ip *dst);
 struct net_bridge_mdb_entry *
@@ -1004,6 +1015,10 @@ int br_mdb_hash_init(struct net_bridge *br);
 void br_mdb_hash_fini(struct net_bridge *br);
 void br_mdb_notify(struct net_device *dev, struct net_bridge_mdb_entry *mp,
 		   struct net_bridge_port_group *pg, int type);
+#ifdef CONFIG_NET_SWITCHDEV
+void br_mdb_flag_change_notify(struct net_device *dev, struct net_bridge_mdb_entry *mp,
+			       struct net_bridge_port_group *pg);
+#endif
 void br_rtr_notify(struct net_device *dev, struct net_bridge_mcast_port *pmctx,
 		   int type);
 void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index 68dccc2ff7b1..5b09cfcdf3f3 100644
--- a/net/bridge/br_switchdev.c
+++ b/net/bridge/br_switchdev.c
@@ -504,20 +504,41 @@ static void br_switchdev_mdb_complete(struct net_device *dev, int err, void *pri
 	struct net_bridge_mdb_entry *mp;
 	struct net_bridge_port *port = data->port;
 	struct net_bridge *br = port->br;
+	bool offload_changed = false;
+	bool failed_changed = false;
+	u8 notify;
 
 	spin_lock_bh(&br->multicast_lock);
 	mp = br_mdb_ip_get(br, &data->ip);
 	if (!mp)
 		goto out;
+
+	notify = br->multicast_ctx.multicast_mdb_notify_on_flag_change;
+
 	for (pp = &mp->ports; (p = mlock_dereference(*pp, br)) != NULL;
 	     pp = &p->next) {
 		if (p->key.port != port)
 			continue;
 
-		if (err)
+		if (err) {
+			if (!(p->flags & MDB_PG_FLAGS_OFFLOAD_FAILED))
+				failed_changed = true;
 			p->flags |= MDB_PG_FLAGS_OFFLOAD_FAILED;
-		else
+		} else {
+			if (!(p->flags & MDB_PG_FLAGS_OFFLOAD))
+				offload_changed = true;
 			p->flags |= MDB_PG_FLAGS_OFFLOAD;
+		}
+
+		if (notify == MDB_NOTIFY_ON_FLAG_CHANGE_DISABLE ||
+		    (!offload_changed && !failed_changed))
+			continue;
+
+		if (notify == MDB_NOTIFY_ON_FLAG_CHANGE_FAIL_ONLY &&
+		    !failed_changed)
+			continue;
+
+		br_mdb_flag_change_notify(br->dev, mp, p);
 	}
 out:
 	spin_unlock_bh(&br->multicast_lock);
-- 
2.49.0