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>

net/bridge/Makefile

@@ -6,7 +6,8 @@ obj-$(CONFIG_BRIDGE) += bridge.o
 
 bridge-y	:= br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \
 			br_ioctl.o br_stp.o br_stp_bpdu.o \
-			br_stp_if.o br_stp_timer.o br_netlink.o
+			br_stp_if.o br_stp_timer.o br_netlink.o \
+			br_netlink_tunnel.o
 
 bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o
 
@@ -18,7 +19,7 @@ obj-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
 
 bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o
 
-bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o
+bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o br_vlan_tunnel.o
 
 bridge-$(CONFIG_NET_SWITCHDEV) += br_switchdev.o
 

net/bridge/br_netlink.c

@@ -20,6 +20,7 @@
 
 #include "br_private.h"
 #include "br_private_stp.h"
+#include "br_private_tunnel.h"
 
 static int __get_num_vlan_infos(struct net_bridge_vlan_group *vg,
 				u32 filter_mask)
@@ -95,9 +96,10 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
 					   u32 filter_mask)
 {
 	struct net_bridge_vlan_group *vg = NULL;
-	struct net_bridge_port *p;
+	struct net_bridge_port *p = NULL;
 	struct net_bridge *br;
 	int num_vlan_infos;
+	size_t vinfo_sz = 0;
 
 	rcu_read_lock();
 	if (br_port_exists(dev)) {
@@ -110,8 +112,13 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
 	num_vlan_infos = br_get_num_vlan_infos(vg, filter_mask);
 	rcu_read_unlock();
 
+	if (p && (p->flags & BR_VLAN_TUNNEL))
+		vinfo_sz += br_get_vlan_tunnel_info_size(vg);
+
 	/* Each VLAN is returned in bridge_vlan_info along with flags */
-	return num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));
+	vinfo_sz += num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));
+
+	return vinfo_sz;
 }
 
 static inline size_t br_port_info_size(void)
@@ -128,6 +135,7 @@ static inline size_t br_port_info_size(void)
 		+ nla_total_size(1)	/* IFLA_BRPORT_UNICAST_FLOOD */
 		+ nla_total_size(1)	/* IFLA_BRPORT_PROXYARP */
 		+ nla_total_size(1)	/* IFLA_BRPORT_PROXYARP_WIFI */
+		+ nla_total_size(1)	/* IFLA_BRPORT_VLAN_TUNNEL */
 		+ nla_total_size(sizeof(struct ifla_bridge_id))	/* IFLA_BRPORT_ROOT_ID */
 		+ nla_total_size(sizeof(struct ifla_bridge_id))	/* IFLA_BRPORT_BRIDGE_ID */
 		+ nla_total_size(sizeof(u16))	/* IFLA_BRPORT_DESIGNATED_PORT */
@@ -194,7 +202,9 @@ static int br_port_fill_attrs(struct sk_buff *skb,
 	    nla_put_u16(skb, IFLA_BRPORT_NO, p->port_no) ||
 	    nla_put_u8(skb, IFLA_BRPORT_TOPOLOGY_CHANGE_ACK,
 		       p->topology_change_ack) ||
-	    nla_put_u8(skb, IFLA_BRPORT_CONFIG_PENDING, p->config_pending))
+	    nla_put_u8(skb, IFLA_BRPORT_CONFIG_PENDING, p->config_pending) ||
+	    nla_put_u8(skb, IFLA_BRPORT_VLAN_TUNNEL, !!(p->flags &
+							BR_VLAN_TUNNEL)))
 		return -EMSGSIZE;
 
 	timerval = br_timer_value(&p->message_age_timer);
@@ -417,6 +427,9 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 			err = br_fill_ifvlaninfo_compressed(skb, vg);
 		else
 			err = br_fill_ifvlaninfo(skb, vg);
+
+		if (port && (port->flags & BR_VLAN_TUNNEL))
+			err = br_fill_vlan_tunnel_info(skb, vg);
 		rcu_read_unlock();
 		if (err)
 			goto nla_put_failure;
@@ -517,60 +530,91 @@ static int br_vlan_info(struct net_bridge *br, struct net_bridge_port *p,
 	return err;
 }
 
+static int br_process_vlan_info(struct net_bridge *br,
+				struct net_bridge_port *p, int cmd,
+				struct bridge_vlan_info *vinfo_curr,
+				struct bridge_vlan_info **vinfo_last)
+{
+	if (!vinfo_curr->vid || vinfo_curr->vid >= VLAN_VID_MASK)
+		return -EINVAL;
+
+	if (vinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN) {
+		/* check if we are already processing a range */
+		if (*vinfo_last)
+			return -EINVAL;
+		*vinfo_last = vinfo_curr;
+		/* don't allow range of pvids */
+		if ((*vinfo_last)->flags & BRIDGE_VLAN_INFO_PVID)
+			return -EINVAL;
+		return 0;
+	}
+
+	if (*vinfo_last) {
+		struct bridge_vlan_info tmp_vinfo;
+		int v, err;
+
+		if (!(vinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_END))
+			return -EINVAL;
+
+		if (vinfo_curr->vid <= (*vinfo_last)->vid)
+			return -EINVAL;
+
+		memcpy(&tmp_vinfo, *vinfo_last,
+		       sizeof(struct bridge_vlan_info));
+		for (v = (*vinfo_last)->vid; v <= vinfo_curr->vid; v++) {
+			tmp_vinfo.vid = v;
+			err = br_vlan_info(br, p, cmd, &tmp_vinfo);
+			if (err)
+				break;
+		}
+		*vinfo_last = NULL;
+
+		return 0;
+	}
+
+	return br_vlan_info(br, p, cmd, vinfo_curr);
+}
+
 static int br_afspec(struct net_bridge *br,
 		     struct net_bridge_port *p,
 		     struct nlattr *af_spec,
 		     int cmd)
 {
-	struct bridge_vlan_info *vinfo_start = NULL;
-	struct bridge_vlan_info *vinfo = NULL;
+	struct bridge_vlan_info *vinfo_curr = NULL;
+	struct bridge_vlan_info *vinfo_last = NULL;
 	struct nlattr *attr;
-	int err = 0;
-	int rem;
+	struct vtunnel_info tinfo_last = {};
+	struct vtunnel_info tinfo_curr = {};
+	int err = 0, rem;
 
 	nla_for_each_nested(attr, af_spec, rem) {
-		if (nla_type(attr) != IFLA_BRIDGE_VLAN_INFO)
-			continue;
-		if (nla_len(attr) != sizeof(struct bridge_vlan_info))
-			return -EINVAL;
-		vinfo = nla_data(attr);
-		if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
-			return -EINVAL;
-		if (vinfo->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN) {
-			if (vinfo_start)
+		err = 0;
+		switch (nla_type(attr)) {
+		case IFLA_BRIDGE_VLAN_TUNNEL_INFO:
+			if (!(p->flags & BR_VLAN_TUNNEL))
 				return -EINVAL;
-			vinfo_start = vinfo;
-			/* don't allow range of pvids */
-			if (vinfo_start->flags & BRIDGE_VLAN_INFO_PVID)
+			err = br_parse_vlan_tunnel_info(attr, &tinfo_curr);
+			if (err)
+				return err;
+			err = br_process_vlan_tunnel_info(br, p, cmd,
+							  &tinfo_curr,
+							  &tinfo_last);
+			if (err)
+				return err;
+			break;
+		case IFLA_BRIDGE_VLAN_INFO:
+			if (nla_len(attr) != sizeof(struct bridge_vlan_info))
 				return -EINVAL;
-			continue;
+			vinfo_curr = nla_data(attr);
+			err = br_process_vlan_info(br, p, cmd, vinfo_curr,
+						   &vinfo_last);
+			if (err)
+				return err;
+			break;
 		}
 
-		if (vinfo_start) {
-			struct bridge_vlan_info tmp_vinfo;
-			int v;
-
-			if (!(vinfo->flags & BRIDGE_VLAN_INFO_RANGE_END))
-				return -EINVAL;
-
-			if (vinfo->vid <= vinfo_start->vid)
-				return -EINVAL;
-
-			memcpy(&tmp_vinfo, vinfo_start,
-			       sizeof(struct bridge_vlan_info));
-
-			for (v = vinfo_start->vid; v <= vinfo->vid; v++) {
-				tmp_vinfo.vid = v;
-				err = br_vlan_info(br, p, cmd, &tmp_vinfo);
-				if (err)
-					break;
-			}
-			vinfo_start = NULL;
-		} else {
-			err = br_vlan_info(br, p, cmd, vinfo);
-		}
 		if (err)
-			break;
+			return err;
 	}
 
 	return err;
@@ -630,8 +674,9 @@ static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 /* Process bridge protocol info on port */
 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 {
-	int err;
 	unsigned long old_flags = p->flags;
+	bool br_vlan_tunnel_old = false;
+	int err;
 
 	br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 	br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
@@ -644,6 +689,11 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 	br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
 	br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
 
+	br_vlan_tunnel_old = (p->flags & BR_VLAN_TUNNEL) ? true : false;
+	br_set_port_flag(p, tb, IFLA_BRPORT_VLAN_TUNNEL, BR_VLAN_TUNNEL);
+	if (br_vlan_tunnel_old && !(p->flags & BR_VLAN_TUNNEL))
+		nbp_vlan_tunnel_info_flush(p);
+
 	if (tb[IFLA_BRPORT_COST]) {
 		err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 		if (err)