net: bridge: vlan: add per-vlan state

The first per-vlan option added is state, it is needed for EVPN and for
per-vlan STP. The state allows to control the forwarding on per-vlan
basis. The vlan state is considered only if the port state is forwarding
in order to avoid conflicts and be consistent. br_allowed_egress is
called only when the state is forwarding, but the ingress case is a bit
more complicated due to the fact that we may have the transition between
port:BR_STATE_FORWARDING -> vlan:BR_STATE_LEARNING which should still
allow the bridge to learn from the packet after vlan filtering and it will
be dropped after that. Also to optimize the pvid state check we keep a
copy in the vlan group to avoid one lookup. The state members are
modified with *_ONCE() to annotate the lockless access.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 50 insertions, 2 deletions

diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c
index 27275ac3e42e..cd2eb194eb98 100644
--- a/net/bridge/br_vlan_options.c
+++ b/net/bridge/br_vlan_options.c
@@ -11,16 +11,54 @@
 bool br_vlan_opts_eq(const struct net_bridge_vlan *v1,
 		     const struct net_bridge_vlan *v2)
 {
-	return true;
+	return v1->state == v2->state;
 }
 
 bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v)
 {
-	return true;
+	return !nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_STATE,
+			   br_vlan_get_state(v));
 }
 
 size_t br_vlan_opts_nl_size(void)
 {
+	return nla_total_size(sizeof(u8)); /* BRIDGE_VLANDB_ENTRY_STATE */
+}
+
+static int br_vlan_modify_state(struct net_bridge_vlan_group *vg,
+				struct net_bridge_vlan *v,
+				u8 state,
+				bool *changed,
+				struct netlink_ext_ack *extack)
+{
+	struct net_bridge *br;
+
+	ASSERT_RTNL();
+
+	if (state > BR_STATE_BLOCKING) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid vlan state");
+		return -EINVAL;
+	}
+
+	if (br_vlan_is_brentry(v))
+		br = v->br;
+	else
+		br = v->port->br;
+
+	if (br->stp_enabled == BR_KERNEL_STP) {
+		NL_SET_ERR_MSG_MOD(extack, "Can't modify vlan state when using kernel STP");
+		return -EBUSY;
+	}
+
+	if (v->state == state)
+		return 0;
+
+	if (v->vid == br_get_pvid(vg))
+		br_vlan_set_pvid_state(vg, state);
+
+	br_vlan_set_state(v, state);
+	*changed = true;
+
 	return 0;
 }
 
@@ -32,7 +70,17 @@ static int br_vlan_process_one_opts(const struct net_bridge *br,
 				    bool *changed,
 				    struct netlink_ext_ack *extack)
 {
+	int err;
+
 	*changed = false;
+	if (tb[BRIDGE_VLANDB_ENTRY_STATE]) {
+		u8 state = nla_get_u8(tb[BRIDGE_VLANDB_ENTRY_STATE]);
+
+		err = br_vlan_modify_state(vg, v, state, changed, extack);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }