Merge branch 'vxlan-ipv4-ipv6'

Jiri Benc says:

====================
vxlan: support both IPv4 and IPv6 sockets

Note: this needs net merged into net-next in order to apply.

It's currently not easy enough to work with metadata based vxlan tunnels. In
particular, it's necessary to create separate network interfaces for IPv4
and IPv6 tunneling. Assigning an IPv6 address to an IPv4 interface is
allowed yet won't do what's expected. With route based tunneling, one has to
pay attention to use the vxlan interface opened with the correct family.
Other users of this (openvswitch) would need to always create two vxlan
interfaces.

Furthermore, there's no sane API for creating an IPv6 vxlan metadata based
interface.

This patchset simplifies this by opening both IPv4 and IPv6 socket if the
vxlan interface has the metadata flag (IFLA_VXLAN_COLLECT_METADATA) set.
Assignment of addresses etc. works as expected after this.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -75,8 +75,7 @@ static struct rtnl_link_ops vxlan_link_ops;
 
 static const u8 all_zeros_mac[ETH_ALEN];
 
-static struct vxlan_sock *vxlan_sock_add(struct net *net, __be16 port,
-					 bool no_share, u32 flags);
+static int vxlan_sock_add(struct vxlan_dev *vxlan);
 
 /* per-network namespace private data for this module */
 struct vxlan_net {
@@ -994,19 +993,30 @@ static bool vxlan_snoop(struct net_device *dev,
 static bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev)
 {
 	struct vxlan_dev *vxlan;
+	unsigned short family = dev->default_dst.remote_ip.sa.sa_family;
 
 	/* The vxlan_sock is only used by dev, leaving group has
 	 * no effect on other vxlan devices.
 	 */
-	if (atomic_read(&dev->vn_sock->refcnt) == 1)
+	if (family == AF_INET && dev->vn4_sock &&
+	    atomic_read(&dev->vn4_sock->refcnt) == 1)
 		return false;
+#if IS_ENABLED(CONFIG_IPV6)
+	if (family == AF_INET6 && dev->vn6_sock &&
+	    atomic_read(&dev->vn6_sock->refcnt) == 1)
+		return false;
+#endif
 
 	list_for_each_entry(vxlan, &vn->vxlan_list, next) {
 		if (!netif_running(vxlan->dev) || vxlan == dev)
 			continue;
 
-		if (vxlan->vn_sock != dev->vn_sock)
+		if (family == AF_INET && vxlan->vn4_sock != dev->vn4_sock)
+			continue;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (family == AF_INET6 && vxlan->vn6_sock != dev->vn6_sock)
 			continue;
+#endif
 
 		if (!vxlan_addr_equal(&vxlan->default_dst.remote_ip,
 				      &dev->default_dst.remote_ip))
@@ -1022,15 +1032,16 @@ static bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev)
 	return false;
 }
 
-static void vxlan_sock_release(struct vxlan_sock *vs)
+static void __vxlan_sock_release(struct vxlan_sock *vs)
 {
-	struct sock *sk = vs->sock->sk;
-	struct net *net = sock_net(sk);
-	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+	struct vxlan_net *vn;
 
+	if (!vs)
+		return;
 	if (!atomic_dec_and_test(&vs->refcnt))
 		return;
 
+	vn = net_generic(sock_net(vs->sock->sk), vxlan_net_id);
 	spin_lock(&vn->sock_lock);
 	hlist_del_rcu(&vs->hlist);
 	vxlan_notify_del_rx_port(vs);
@@ -1039,32 +1050,43 @@ static void vxlan_sock_release(struct vxlan_sock *vs)
 	queue_work(vxlan_wq, &vs->del_work);
 }
 
+static void vxlan_sock_release(struct vxlan_dev *vxlan)
+{
+	__vxlan_sock_release(vxlan->vn4_sock);
+#if IS_ENABLED(CONFIG_IPV6)
+	__vxlan_sock_release(vxlan->vn6_sock);
+#endif
+}
+
 /* Update multicast group membership when first VNI on
  * multicast address is brought up
  */
 static int vxlan_igmp_join(struct vxlan_dev *vxlan)
 {
-	struct vxlan_sock *vs = vxlan->vn_sock;
-	struct sock *sk = vs->sock->sk;
+	struct sock *sk;
 	union vxlan_addr *ip = &vxlan->default_dst.remote_ip;
 	int ifindex = vxlan->default_dst.remote_ifindex;
 	int ret = -EINVAL;
 
-	lock_sock(sk);
 	if (ip->sa.sa_family == AF_INET) {
 		struct ip_mreqn mreq = {
 			.imr_multiaddr.s_addr	= ip->sin.sin_addr.s_addr,
 			.imr_ifindex		= ifindex,
 		};
 
+		sk = vxlan->vn4_sock->sock->sk;
+		lock_sock(sk);
 		ret = ip_mc_join_group(sk, &mreq);
+		release_sock(sk);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else {
+		sk = vxlan->vn6_sock->sock->sk;
+		lock_sock(sk);
 		ret = ipv6_stub->ipv6_sock_mc_join(sk, ifindex,
 						   &ip->sin6.sin6_addr);
+		release_sock(sk);
 #endif
 	}
-	release_sock(sk);
 
 	return ret;
 }
@@ -1072,27 +1094,30 @@ static int vxlan_igmp_join(struct vxlan_dev *vxlan)
 /* Inverse of vxlan_igmp_join when last VNI is brought down */
 static int vxlan_igmp_leave(struct vxlan_dev *vxlan)
 {
-	struct vxlan_sock *vs = vxlan->vn_sock;
-	struct sock *sk = vs->sock->sk;
+	struct sock *sk;
 	union vxlan_addr *ip = &vxlan->default_dst.remote_ip;
 	int ifindex = vxlan->default_dst.remote_ifindex;
 	int ret = -EINVAL;
 
-	lock_sock(sk);
 	if (ip->sa.sa_family == AF_INET) {
 		struct ip_mreqn mreq = {
 			.imr_multiaddr.s_addr	= ip->sin.sin_addr.s_addr,
 			.imr_ifindex		= ifindex,
 		};
 
+		sk = vxlan->vn4_sock->sock->sk;
+		lock_sock(sk);
 		ret = ip_mc_leave_group(sk, &mreq);
+		release_sock(sk);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else {
+		sk = vxlan->vn6_sock->sock->sk;
+		lock_sock(sk);
 		ret = ipv6_stub->ipv6_sock_mc_drop(sk, ifindex,
 						   &ip->sin6.sin6_addr);
+		release_sock(sk);
 #endif
 	}
-	release_sock(sk);
 
 	return ret;
 }
@@ -1873,8 +1898,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 {
 	struct ip_tunnel_info *info;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	struct sock *sk = vxlan->vn_sock->sock->sk;
-	unsigned short family = vxlan_get_sk_family(vxlan->vn_sock);
+	struct sock *sk;
 	struct rtable *rt = NULL;
 	const struct iphdr *old_iph;
 	struct flowi4 fl4;
@@ -1901,13 +1925,10 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 				  dev->name);
 			goto drop;
 		}
-		if (family != ip_tunnel_info_af(info))
-			goto drop;
-
 		dst_port = info->key.tp_dst ? : vxlan->cfg.dst_port;
 		vni = be64_to_cpu(info->key.tun_id);
-		remote_ip.sa.sa_family = family;
-		if (family == AF_INET)
+		remote_ip.sa.sa_family = ip_tunnel_info_af(info);
+		if (remote_ip.sa.sa_family == AF_INET)
 			remote_ip.sin.sin_addr.s_addr = info->key.u.ipv4.dst;
 		else
 			remote_ip.sin6.sin6_addr = info->key.u.ipv6.dst;
@@ -1952,6 +1973,10 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 	}
 
 	if (dst->sa.sa_family == AF_INET) {
+		if (!vxlan->vn4_sock)
+			goto drop;
+		sk = vxlan->vn4_sock->sock->sk;
+
 		if (info && (info->key.tun_flags & TUNNEL_DONT_FRAGMENT))
 			df = htons(IP_DF);
 
@@ -2013,6 +2038,10 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		struct flowi6 fl6;
 		u32 rt6i_flags;
 
+		if (!vxlan->vn6_sock)
+			goto drop;
+		sk = vxlan->vn6_sock->sock->sk;
+
 		memset(&fl6, 0, sizeof(fl6));
 		fl6.flowi6_oif = rdst ? rdst->remote_ifindex : 0;
 		fl6.daddr = dst->sin6.sin6_addr;
@@ -2204,7 +2233,6 @@ static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan)
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
 	__u32 vni = vxlan->default_dst.remote_vni;
 
-	vxlan->vn_sock = vs;
 	spin_lock(&vn->sock_lock);
 	hlist_add_head_rcu(&vxlan->hlist, vni_head(vs, vni));
 	spin_unlock(&vn->sock_lock);
@@ -2244,22 +2272,18 @@ static void vxlan_uninit(struct net_device *dev)
 static int vxlan_open(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	struct vxlan_sock *vs;
-	int ret = 0;
-
-	vs = vxlan_sock_add(vxlan->net, vxlan->cfg.dst_port,
-			    vxlan->cfg.no_share, vxlan->flags);
-	if (IS_ERR(vs))
-		return PTR_ERR(vs);
+	int ret;
 
-	vxlan_vs_add_dev(vs, vxlan);
+	ret = vxlan_sock_add(vxlan);
+	if (ret < 0)
+		return ret;
 
 	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
 		ret = vxlan_igmp_join(vxlan);
 		if (ret == -EADDRINUSE)
 			ret = 0;
 		if (ret) {
-			vxlan_sock_release(vs);
+			vxlan_sock_release(vxlan);
 			return ret;
 		}
 	}
@@ -2294,7 +2318,6 @@ 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);
-	struct vxlan_sock *vs = vxlan->vn_sock;
 	int ret = 0;
 
 	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
@@ -2304,7 +2327,7 @@ static int vxlan_stop(struct net_device *dev)
 	del_timer_sync(&vxlan->age_timer);
 
 	vxlan_flush(vxlan);
-	vxlan_sock_release(vs);
+	vxlan_sock_release(vxlan);
 
 	return ret;
 }
@@ -2540,14 +2563,13 @@ static struct socket *vxlan_create_sock(struct net *net, bool ipv6,
 }
 
 /* Create new listen socket if needed */
-static struct vxlan_sock *vxlan_socket_create(struct net *net, __be16 port,
-					      u32 flags)
+static struct vxlan_sock *vxlan_socket_create(struct net *net, bool ipv6,
+					      __be16 port, u32 flags)
 {
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
 	struct vxlan_sock *vs;
 	struct socket *sock;
 	unsigned int h;
-	bool ipv6 = !!(flags & VXLAN_F_IPV6);
 	struct udp_tunnel_sock_cfg tunnel_cfg;
 
 	vs = kzalloc(sizeof(*vs), GFP_KERNEL);
@@ -2592,27 +2614,53 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, __be16 port,
 	return vs;
 }
 
-static struct vxlan_sock *vxlan_sock_add(struct net *net, __be16 port,
-					 bool no_share, u32 flags)
+static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 {
-	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
-	struct vxlan_sock *vs;
-	bool ipv6 = flags & VXLAN_F_IPV6;
+	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+	struct vxlan_sock *vs = NULL;
 
-	if (!no_share) {
+	if (!vxlan->cfg.no_share) {
 		spin_lock(&vn->sock_lock);
-		vs = vxlan_find_sock(net, ipv6 ? AF_INET6 : AF_INET, port,
-				     flags);
-		if (vs) {
-			if (!atomic_add_unless(&vs->refcnt, 1, 0))
-				vs = ERR_PTR(-EBUSY);
+		vs = vxlan_find_sock(vxlan->net, ipv6 ? AF_INET6 : AF_INET,
+				     vxlan->cfg.dst_port, vxlan->flags);
+		if (vs && !atomic_add_unless(&vs->refcnt, 1, 0)) {
 			spin_unlock(&vn->sock_lock);
-			return vs;
+			return -EBUSY;
 		}
 		spin_unlock(&vn->sock_lock);
 	}
+	if (!vs)
+		vs = vxlan_socket_create(vxlan->net, ipv6,
+					 vxlan->cfg.dst_port, vxlan->flags);
+	if (IS_ERR(vs))
+		return PTR_ERR(vs);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (ipv6)
+		vxlan->vn6_sock = vs;
+	else
+#endif
+		vxlan->vn4_sock = vs;
+	vxlan_vs_add_dev(vs, vxlan);
+	return 0;
+}
 
-	return vxlan_socket_create(net, port, flags);
+static int vxlan_sock_add(struct vxlan_dev *vxlan)
+{
+	bool ipv6 = vxlan->flags & VXLAN_F_IPV6;
+	bool metadata = vxlan->flags & VXLAN_F_COLLECT_METADATA;
+	int ret = 0;
+
+	vxlan->vn4_sock = NULL;
+#if IS_ENABLED(CONFIG_IPV6)
+	vxlan->vn6_sock = NULL;
+	if (ipv6 || metadata)
+		ret = __vxlan_sock_add(vxlan, true);
+#endif
+	if (!ret && (!ipv6 || metadata))
+		ret = __vxlan_sock_add(vxlan, false);
+	if (ret < 0)
+		vxlan_sock_release(vxlan);
+	return ret;
 }
 
 static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
@@ -2621,6 +2669,7 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
 	struct vxlan_net *vn = net_generic(src_net, vxlan_net_id);
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_rdst *dst = &vxlan->default_dst;
+	unsigned short needed_headroom = ETH_HLEN;
 	int err;
 	bool use_ipv6 = false;
 	__be16 default_port = vxlan->cfg.dst_port;
@@ -2640,6 +2689,7 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
 		if (!IS_ENABLED(CONFIG_IPV6))
 			return -EPFNOSUPPORT;
 		use_ipv6 = true;
+		vxlan->flags |= VXLAN_F_IPV6;
 	}
 
 	if (conf->remote_ifindex) {
@@ -2660,22 +2710,21 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
 				pr_info("IPv6 is disabled via sysctl\n");
 				return -EPERM;
 			}
-			vxlan->flags |= VXLAN_F_IPV6;
 		}
 #endif
 
 		if (!conf->mtu)
 			dev->mtu = lowerdev->mtu - (use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
 
-		dev->needed_headroom = lowerdev->hard_header_len +
-				       (use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
-	} else if (use_ipv6) {
-		vxlan->flags |= VXLAN_F_IPV6;
-		dev->needed_headroom = ETH_HLEN + VXLAN6_HEADROOM;
-	} else {
-		dev->needed_headroom = ETH_HLEN + VXLAN_HEADROOM;
+		needed_headroom = lowerdev->hard_header_len;
 	}
 
+	if (use_ipv6 || conf->flags & VXLAN_F_COLLECT_METADATA)
+		needed_headroom += VXLAN6_HEADROOM;
+	else
+		needed_headroom += VXLAN_HEADROOM;
+	dev->needed_headroom = needed_headroom;
+
 	memcpy(&vxlan->cfg, conf, sizeof(*conf));
 	if (!vxlan->cfg.dst_port)
 		vxlan->cfg.dst_port = default_port;

include/net/vxlan.h

@@ -152,7 +152,10 @@ struct vxlan_config {
 struct vxlan_dev {
 	struct hlist_node hlist;	/* vni hash table */
 	struct list_head  next;		/* vxlan's per namespace list */
-	struct vxlan_sock *vn_sock;	/* listening socket */
+	struct vxlan_sock *vn4_sock;	/* listening socket for IPv4 */
+#if IS_ENABLED(CONFIG_IPV6)
+	struct vxlan_sock *vn6_sock;	/* listening socket for IPv6 */
+#endif
 	struct net_device *dev;
 	struct net	  *net;		/* netns for packet i/o */
 	struct vxlan_rdst default_dst;	/* default destination */
@@ -195,9 +198,14 @@ struct vxlan_dev {
 struct net_device *vxlan_dev_create(struct net *net, const char *name,
 				    u8 name_assign_type, struct vxlan_config *conf);
 
-static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan)
+static inline __be16 vxlan_dev_dst_port(struct vxlan_dev *vxlan,
+					unsigned short family)
 {
-	return inet_sk(vxlan->vn_sock->sock->sk)->inet_sport;
+#if IS_ENABLED(CONFIG_IPV6)
+	if (family == AF_INET6)
+		return inet_sk(vxlan->vn6_sock->sock->sk)->inet_sport;
+#endif
+	return inet_sk(vxlan->vn4_sock->sock->sk)->inet_sport;
 }
 
 static inline netdev_features_t vxlan_features_check(struct sk_buff *skb,

net/openvswitch/vport-vxlan.c

@@ -151,7 +151,8 @@ static int vxlan_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
 {
 	struct vxlan_dev *vxlan = netdev_priv(vport->dev);
 	struct net *net = ovs_dp_get_net(vport->dp);
-	__be16 dst_port = vxlan_dev_dst_port(vxlan);
+	unsigned short family = ip_tunnel_info_af(upcall->egress_tun_info);
+	__be16 dst_port = vxlan_dev_dst_port(vxlan, family);
 	__be16 src_port;
 	int port_min;
 	int port_max;