net: bridge: resolve forwarding path for VLAN tag actions in bridge devices

Depending on the VLAN settings of the bridge and the port, the bridge can
either add or remove a tag. When vlan filtering is enabled, the fdb lookup
also needs to know the VLAN tag/proto for the destination address
To provide this, keep track of the stack of VLAN tags for the path in the
lookup context

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 0 deletions

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 6f961cb5f771..c92240b21c4a 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1339,6 +1339,59 @@ int br_vlan_get_pvid_rcu(const struct net_device *dev, u16 *p_pvid)
 }
 EXPORT_SYMBOL_GPL(br_vlan_get_pvid_rcu);
 
+void br_vlan_fill_forward_path_pvid(struct net_bridge *br,
+				    struct net_device_path_ctx *ctx,
+				    struct net_device_path *path)
+{
+	struct net_bridge_vlan_group *vg;
+	int idx = ctx->num_vlans - 1;
+	u16 vid;
+
+	path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP;
+
+	if (!br_opt_get(br, BROPT_VLAN_ENABLED))
+		return;
+
+	vg = br_vlan_group(br);
+
+	if (idx >= 0 &&
+	    ctx->vlan[idx].proto == br->vlan_proto) {
+		vid = ctx->vlan[idx].id;
+	} else {
+		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_TAG;
+		vid = br_get_pvid(vg);
+	}
+
+	path->bridge.vlan_id = vid;
+	path->bridge.vlan_proto = br->vlan_proto;
+}
+
+int br_vlan_fill_forward_path_mode(struct net_bridge *br,
+				   struct net_bridge_port *dst,
+				   struct net_device_path *path)
+{
+	struct net_bridge_vlan_group *vg;
+	struct net_bridge_vlan *v;
+
+	if (!br_opt_get(br, BROPT_VLAN_ENABLED))
+		return 0;
+
+	vg = nbp_vlan_group_rcu(dst);
+	v = br_vlan_find(vg, path->bridge.vlan_id);
+	if (!v || !br_vlan_should_use(v))
+		return -EINVAL;
+
+	if (!(v->flags & BRIDGE_VLAN_INFO_UNTAGGED))
+		return 0;
+
+	if (path->bridge.vlan_mode == DEV_PATH_BR_VLAN_TAG)
+		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP;
+	else
+		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG;
+
+	return 0;
+}
+
 int br_vlan_get_info(const struct net_device *dev, u16 vid,
 		     struct bridge_vlan_info *p_vinfo)
 {