vxlan: vni filtering support on collect metadata device

This patch adds vnifiltering support to collect metadata device.

Motivation:
You can only use a single vxlan collect metadata device for a given
vxlan udp port in the system today. The vxlan collect metadata device
terminates all received vxlan packets. As shown in the below diagram,
there are use-cases where you need to support multiple such vxlan devices in
independent bridge domains. Each vxlan device must terminate the vni's
it is configured for.
Example usecase: In a service provider network a service provider
typically supports multiple bridge domains with overlapping vlans.
One bridge domain per customer. Vlans in each bridge domain are
mapped to globally unique vxlan ranges assigned to each customer.

vnifiltering support in collect metadata devices terminates only configured
vnis. This is similar to vlan filtering in bridge driver. The vni filtering
capability is provided by a new flag on collect metadata device.

In the below pic:
	- customer1 is mapped to br1 bridge domain
	- customer2 is mapped to br2 bridge domain
	- customer1 vlan 10-11 is mapped to vni 1001-1002
	- customer2 vlan 10-11 is mapped to vni 2001-2002
	- br1 and br2 are vlan filtering bridges
	- vxlan1 and vxlan2 are collect metadata devices with
	  vnifiltering enabled

┌──────────────────────────────────────────────────────────────────┐
│  switch                                                          │
│                                                                  │
│         ┌───────────┐                 ┌───────────┐              │
│         │           │                 │           │              │
│         │   br1     │                 │   br2     │              │
│         └┬─────────┬┘                 └──┬───────┬┘              │
│     vlans│         │               vlans │       │               │
│     10,11│         │                10,11│       │               │
│          │     vlanvnimap:               │    vlanvnimap:        │
│          │       10-1001,11-1002         │      10-2001,11-2002  │
│          │         │                     │       │               │
│   ┌──────┴┐     ┌──┴─────────┐       ┌───┴────┐  │               │
│   │ swp1  │     │vxlan1      │       │ swp2   │ ┌┴─────────────┐ │
│   │       │     │  vnifilter:│       │        │ │vxlan2        │ │
│   └───┬───┘     │   1001,1002│       └───┬────┘ │ vnifilter:   │ │
│       │         └────────────┘           │      │  2001,2002   │ │
│       │                                  │      └──────────────┘ │
│       │                                  │                       │
└───────┼──────────────────────────────────┼───────────────────────┘
        │                                  │
        │                                  │
  ┌─────┴───────┐                          │
  │  customer1  │                    ┌─────┴──────┐
  │ host/VM     │                    │customer2   │
  └─────────────┘                    │ host/VM    │
                                     └────────────┘

With this implementation, vxlan dst metadata device can
be associated with range of vnis.
struct vxlan_vni_node is introduced to represent
a configured vni. We start with vni and its
associated remote_ip in this structure. This
structure can be extended to bring in other
per vni attributes if there are usecases for it.
A vni inherits an attribute from the base vxlan device
if there is no per vni attributes defined.

struct vxlan_dev gets a new rhashtable for
vnis called vxlan_vni_group. vxlan_vnifilter.c
implements the necessary netlink api, notifications
and helper functions to process and manage lifecycle
of vxlan_vni_node.

This patch also adds new helper functions in vxlan_multicast.c
to handle per vni remote_ip multicast groups which are part
of vxlan_vni_group.

Fix build problems:
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 75 insertions, 21 deletions

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 11286e2191a1..a3c20ad18243 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -145,12 +145,19 @@ static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, int ifindex,
 	struct vxlan_dev_node *node;
 
 	/* For flow based devices, map all packets to VNI 0 */
-	if (vs->flags & VXLAN_F_COLLECT_METADATA)
+	if (vs->flags & VXLAN_F_COLLECT_METADATA &&
+	    !(vs->flags & VXLAN_F_VNIFILTER))
 		vni = 0;
 
 	hlist_for_each_entry_rcu(node, vni_head(vs, vni), hlist) {
-		if (node->vxlan->default_dst.remote_vni != vni)
+		if (!node->vxlan)
 			continue;
+		if (node->vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+			if (!vxlan_vnifilter_lookup(node->vxlan, vni))
+				continue;
+		} else if (node->vxlan->default_dst.remote_vni != vni) {
+			continue;
+		}
 
 		if (IS_ENABLED(CONFIG_IPV6)) {
 			const struct vxlan_config *cfg = &node->vxlan->cfg;
@@ -1478,7 +1485,10 @@ static void vxlan_sock_release(struct vxlan_dev *vxlan)
 	RCU_INIT_POINTER(vxlan->vn4_sock, NULL);
 	synchronize_net();
 
-	vxlan_vs_del_dev(vxlan);
+	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+		vxlan_vs_del_vnigrp(vxlan);
+	else
+		vxlan_vs_del_dev(vxlan);
 
 	if (__vxlan_sock_release_prep(sock4)) {
 		udp_tunnel_sock_release(sock4->sock);
@@ -2857,6 +2867,9 @@ static int vxlan_init(struct net_device *dev)
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	int err;
 
+	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+		vxlan_vnigroup_init(vxlan);
+
 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 	if (!dev->tstats)
 		return -ENOMEM;
@@ -2886,6 +2899,9 @@ static void vxlan_uninit(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 
+	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+		vxlan_vnigroup_uninit(vxlan);
+
 	gro_cells_destroy(&vxlan->gro_cells);
 
 	vxlan_fdb_delete_default(vxlan, vxlan->cfg.vni);
@@ -2903,15 +2919,10 @@ static int vxlan_open(struct net_device *dev)
 	if (ret < 0)
 		return ret;
 
-	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
-		ret = vxlan_igmp_join(vxlan, &vxlan->default_dst.remote_ip,
-				      vxlan->default_dst.remote_ifindex);
-		if (ret == -EADDRINUSE)
-			ret = 0;
-		if (ret) {
-			vxlan_sock_release(vxlan);
-			return ret;
-		}
+	ret = vxlan_multicast_join(vxlan);
+	if (ret) {
+		vxlan_sock_release(vxlan);
+		return ret;
 	}
 
 	if (vxlan->cfg.age_interval)
@@ -2948,13 +2959,9 @@ static void vxlan_flush(struct vxlan_dev *vxlan, bool do_all)
 static int vxlan_stop(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
 	int ret = 0;
 
-	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
-	    !vxlan_group_used(vn, vxlan, NULL, 0))
-		ret = vxlan_igmp_leave(vxlan, &vxlan->default_dst.remote_ip,
-				       vxlan->default_dst.remote_ifindex);
+	vxlan_multicast_leave(vxlan);
 
 	del_timer_sync(&vxlan->age_timer);
 
@@ -3184,6 +3191,7 @@ static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = {
 	[IFLA_VXLAN_REMCSUM_NOPARTIAL]	= { .type = NLA_FLAG },
 	[IFLA_VXLAN_TTL_INHERIT]	= { .type = NLA_FLAG },
 	[IFLA_VXLAN_DF]		= { .type = NLA_U8 },
+	[IFLA_VXLAN_VNIFILTER]	= { .type = NLA_U8 },
 };
 
 static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
@@ -3369,6 +3377,7 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, bool ipv6,
 static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 {
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+	bool metadata = vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA;
 	struct vxlan_sock *vs = NULL;
 	struct vxlan_dev_node *node;
 	int l3mdev_index = 0;
@@ -3404,7 +3413,12 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 		rcu_assign_pointer(vxlan->vn4_sock, vs);
 		node = &vxlan->hlist4;
 	}
-	vxlan_vs_add_dev(vs, vxlan, node);
+
+	if (metadata && (vxlan->cfg.flags & VXLAN_F_VNIFILTER))
+		vxlan_vs_add_vnigrp(vxlan, vs, ipv6);
+	else
+		vxlan_vs_add_dev(vs, vxlan, node);
+
 	return 0;
 }
 
@@ -3431,8 +3445,8 @@ static int vxlan_sock_add(struct vxlan_dev *vxlan)
 	return ret;
 }
 
-static int vxlan_vni_in_use(struct net *src_net, struct vxlan_dev *vxlan,
-			    struct vxlan_config *conf, __be32 vni)
+int vxlan_vni_in_use(struct net *src_net, struct vxlan_dev *vxlan,
+		     struct vxlan_config *conf, __be32 vni)
 {
 	struct vxlan_net *vn = net_generic(src_net, vxlan_net_id);
 	struct vxlan_dev *tmp;
@@ -3440,8 +3454,12 @@ static int vxlan_vni_in_use(struct net *src_net, struct vxlan_dev *vxlan,
 	list_for_each_entry(tmp, &vn->vxlan_list, next) {
 		if (tmp == vxlan)
 			continue;
-		if (tmp->cfg.vni != vni)
+		if (tmp->cfg.flags & VXLAN_F_VNIFILTER) {
+			if (!vxlan_vnifilter_lookup(tmp, vni))
+				continue;
+		} else if (tmp->cfg.vni != vni) {
 			continue;
+		}
 		if (tmp->cfg.dst_port != conf->dst_port)
 			continue;
 		if ((tmp->cfg.flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6)) !=
@@ -4051,6 +4069,21 @@ static int vxlan_nl2conf(struct nlattr *tb[], struct nlattr *data[],
 	if (data[IFLA_VXLAN_DF])
 		conf->df = nla_get_u8(data[IFLA_VXLAN_DF]);
 
+	if (data[IFLA_VXLAN_VNIFILTER]) {
+		err = vxlan_nl2flag(conf, data, IFLA_VXLAN_VNIFILTER,
+				    VXLAN_F_VNIFILTER, changelink, false,
+				    extack);
+		if (err)
+			return err;
+
+		if ((conf->flags & VXLAN_F_VNIFILTER) &&
+		    !(conf->flags & VXLAN_F_COLLECT_METADATA)) {
+			NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VXLAN_VNIFILTER],
+					    "vxlan vnifilter only valid in collect metadata mode");
+			return -EINVAL;
+		}
+	}
+
 	return 0;
 }
 
@@ -4126,6 +4159,19 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 					   dst->remote_ifindex,
 					   true);
 		spin_unlock_bh(&vxlan->hash_lock[hash_index]);
+
+		/* If vni filtering device, also update fdb entries of
+		 * all vnis that were using default remote ip
+		 */
+		if (vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+			err = vxlan_vnilist_update_group(vxlan, &dst->remote_ip,
+							 &conf.remote_ip, extack);
+			if (err) {
+				netdev_adjacent_change_abort(dst->remote_dev,
+							     lowerdev, dev);
+				return err;
+			}
+		}
 	}
 
 	if (conf.age_interval != vxlan->cfg.age_interval)
@@ -4271,6 +4317,11 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	    nla_put_flag(skb, IFLA_VXLAN_REMCSUM_NOPARTIAL))
 		goto nla_put_failure;
 
+	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER &&
+	    nla_put_u8(skb, IFLA_VXLAN_VNIFILTER,
+		       !!(vxlan->cfg.flags & VXLAN_F_VNIFILTER)))
+		goto nla_put_failure;
+
 	return 0;
 
 nla_put_failure:
@@ -4630,6 +4681,8 @@ static int __init vxlan_init_module(void)
 	if (rc)
 		goto out4;
 
+	vxlan_vnifilter_init();
+
 	return 0;
 out4:
 	unregister_switchdev_notifier(&vxlan_switchdev_notifier_block);
@@ -4644,6 +4697,7 @@ late_initcall(vxlan_init_module);
 
 static void __exit vxlan_cleanup_module(void)
 {
+	vxlan_vnifilter_uninit();
 	rtnl_link_unregister(&vxlan_link_ops);
 	unregister_switchdev_notifier(&vxlan_switchdev_notifier_block);
 	unregister_netdevice_notifier(&vxlan_notifier_block);