bridge: Support 802.1ad vlan filtering

This enables us to change the vlan protocol for vlan filtering.
We come to be able to filter frames on the basis of 802.1ad vlan tags
through a bridge.

This also changes br->group_addr if it has not been set by user.
This is needed for an 802.1ad bridge.
(See IEEE 802.1Q-2011 8.13.5.)

Furthermore, this sets br->group_fwd_mask_required so that an 802.1ad
bridge can forward the Nearest Customer Bridge group addresses except
for br->group_addr, which should be passed to higher layer.

To change the vlan protocol, write a protocol in sysfs:
# echo 0x88a8 > /sys/class/net/br0/bridge/vlan_protocol

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 97 insertions, 0 deletions

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 63bd981..2b2774f 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -378,6 +378,33 @@ out:
 	return found;
 }
 
+/* Must be protected by RTNL. */
+static void recalculate_group_addr(struct net_bridge *br)
+{
+	if (br->group_addr_set)
+		return;
+
+	spin_lock_bh(&br->lock);
+	if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q)) {
+		/* Bridge Group Address */
+		br->group_addr[5] = 0x00;
+	} else { /* vlan_enabled && ETH_P_8021AD */
+		/* Provider Bridge Group Address */
+		br->group_addr[5] = 0x08;
+	}
+	spin_unlock_bh(&br->lock);
+}
+
+/* Must be protected by RTNL. */
+void br_recalculate_fwd_mask(struct net_bridge *br)
+{
+	if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q))
+		br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
+	else /* vlan_enabled && ETH_P_8021AD */
+		br->group_fwd_mask_required = BR_GROUPFWD_8021AD &
+					      ~(1u << br->group_addr[5]);
+}
+
 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
 {
 	if (!rtnl_trylock())
@@ -388,12 +415,82 @@ int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
 
 	br->vlan_enabled = val;
 	br_manage_promisc(br);
+	recalculate_group_addr(br);
+	br_recalculate_fwd_mask(br);
 
 unlock:
 	rtnl_unlock();
 	return 0;
 }
 
+int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
+{
+	int err = 0;
+	struct net_bridge_port *p;
+	struct net_port_vlans *pv;
+	__be16 proto, oldproto;
+	u16 vid, errvid;
+
+	if (val != ETH_P_8021Q && val != ETH_P_8021AD)
+		return -EPROTONOSUPPORT;
+
+	if (!rtnl_trylock())
+		return restart_syscall();
+
+	proto = htons(val);
+	if (br->vlan_proto == proto)
+		goto unlock;
+
+	/* Add VLANs for the new proto to the device filter. */
+	list_for_each_entry(p, &br->port_list, list) {
+		pv = rtnl_dereference(p->vlan_info);
+		if (!pv)
+			continue;
+
+		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
+			err = vlan_vid_add(p->dev, proto, vid);
+			if (err)
+				goto err_filt;
+		}
+	}
+
+	oldproto = br->vlan_proto;
+	br->vlan_proto = proto;
+
+	recalculate_group_addr(br);
+	br_recalculate_fwd_mask(br);
+
+	/* Delete VLANs for the old proto from the device filter. */
+	list_for_each_entry(p, &br->port_list, list) {
+		pv = rtnl_dereference(p->vlan_info);
+		if (!pv)
+			continue;
+
+		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
+			vlan_vid_del(p->dev, oldproto, vid);
+	}
+
+unlock:
+	rtnl_unlock();
+	return err;
+
+err_filt:
+	errvid = vid;
+	for_each_set_bit(vid, pv->vlan_bitmap, errvid)
+		vlan_vid_del(p->dev, proto, vid);
+
+	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
+		pv = rtnl_dereference(p->vlan_info);
+		if (!pv)
+			continue;
+
+		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
+			vlan_vid_del(p->dev, proto, vid);
+	}
+
+	goto unlock;
+}
+
 void br_vlan_init(struct net_bridge *br)
 {
 	br->vlan_proto = htons(ETH_P_8021Q);