bridge: per vlan dst_metadata netlink support

This patch adds support to attach per vlan tunnel info dst
metadata. This enables bridge driver to map vlan to tunnel_info
at ingress and egress. It uses the kernel dst_metadata infrastructure.

The initial use case is vlan to vni bridging, but the api is generic
to extend to any tunnel_info in the future:
    - Uapi to configure/unconfigure/dump per vlan tunnel data
    - netlink functions to configure vlan and tunnel_info mapping
    - Introduces bridge port flag BR_LWT_VLAN to enable attach/detach
    dst_metadata to bridged packets on ports. off by default.
    - changes to existing code is mainly refactor some existing vlan
    handling netlink code + hooks for new vlan tunnel code
    - I have kept the vlan tunnel code isolated in separate files.
    - most of the netlink vlan tunnel code is handling of vlan-tunid
    ranges (follows the vlan range handling code). To conserve space
    vlan-tunid by default are always dumped in ranges if applicable.

Use case:
example use for this is a vxlan bridging gateway or vtep
which maps vlans to vn-segments (or vnis).

iproute2 example (patched and pruned iproute2 output to just show
relevant fdb entries):
example shows same host mac learnt on two vni's and
vlan 100 maps to vni 1000, vlan 101 maps to vni 1001

before (netdev per vni):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan1001 vlan 101 master bridge
00:02:00:00:00:03 dev vxlan1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan1000 vlan 100 master bridge
00:02:00:00:00:03 dev vxlan1000 dst 12.0.0.8 self

after this patch with collect metdata in bridged mode (single netdev):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan0 vlan 101 master bridge
00:02:00:00:00:03 dev vxlan0 src_vni 1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan0 vlan 100 master bridge
00:02:00:00:00:03 dev vxlan0 src_vni 1000 dst 12.0.0.8 self

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

1 files changed, 72 insertions, 0 deletions

diff --git a/net/bridge/br_private_tunnel.h b/net/bridge/br_private_tunnel.h
new file mode 100644
index 000000000000..1c8d0d5302cb
--- /dev/null
+++ b/net/bridge/br_private_tunnel.h
@@ -0,0 +1,72 @@
+/*
+ *	Bridge per vlan tunnels
+ *
+ *	Authors:
+ *	Roopa Prabhu		<roopa@cumulusnetworks.com>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _BR_PRIVATE_TUNNEL_H
+#define _BR_PRIVATE_TUNNEL_H
+
+struct vtunnel_info {
+	u32	tunid;
+	u16	vid;
+	u16	flags;
+};
+
+/* br_netlink_tunnel.c */
+int br_parse_vlan_tunnel_info(struct nlattr *attr,
+			      struct vtunnel_info *tinfo);
+int br_process_vlan_tunnel_info(struct net_bridge *br,
+				struct net_bridge_port *p,
+				int cmd,
+				struct vtunnel_info *tinfo_curr,
+				struct vtunnel_info *tinfo_last);
+int br_get_vlan_tunnel_info_size(struct net_bridge_vlan_group *vg);
+int br_fill_vlan_tunnel_info(struct sk_buff *skb,
+			     struct net_bridge_vlan_group *vg);
+
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+/* br_vlan_tunnel.c */
+int vlan_tunnel_init(struct net_bridge_vlan_group *vg);
+void vlan_tunnel_deinit(struct net_bridge_vlan_group *vg);
+int nbp_vlan_tunnel_info_delete(struct net_bridge_port *port, u16 vid);
+int nbp_vlan_tunnel_info_add(struct net_bridge_port *port, u16 vid, u32 tun_id);
+void nbp_vlan_tunnel_info_flush(struct net_bridge_port *port);
+void vlan_tunnel_info_del(struct net_bridge_vlan_group *vg,
+			  struct net_bridge_vlan *vlan);
+#else
+static inline int vlan_tunnel_init(struct net_bridge_vlan_group *vg)
+{
+	return 0;
+}
+
+static inline int nbp_vlan_tunnel_info_delete(struct net_bridge_port *port,
+					      u16 vid)
+{
+	return 0;
+}
+
+static inline int nbp_vlan_tunnel_info_add(struct net_bridge_port *port,
+					   u16 vid, u32 tun_id)
+{
+	return 0;
+}
+
+static inline void nbp_vlan_tunnel_info_flush(struct net_bridge_port *port)
+{
+}
+
+static inline void vlan_tunnel_info_del(struct net_bridge_vlan_group *vg,
+					struct net_bridge_vlan *vlan)
+{
+}
+
+#endif
+
+#endif