[Patch net-next v3 3/4] vxlan: add ipv6 support

[Cong Wang <amwang@redhat.com>]

From: Cong Wang <amwang@redhat.com>

v3: fix many coding style issues
    fix some ugly #ifdef
    rename vxlan_ip to vxlan_addr
    rename ->proto to ->family
    rename ->ip4/->ip6 to ->sin/->sin6

v2: fix some compile error when !CONFIG_IPV6
    improve some code based on Stephen's comments
    use sockaddr suggested by David

This patch adds IPv6 support to vxlan device, as the new version
RFC already mentioned it:

   http://tools.ietf.org/html/draft-mahalingam-dutt-dcops-vxlan-03

Cc: David Stevens <dlstevens@us.ibm.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 drivers/net/vxlan.c          |  544 ++++++++++++++++++++++++++++++++----------
 include/uapi/linux/if_link.h |    2 +
 2 files changed, 425 insertions(+), 121 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index cac4e4f..5fbf0ed 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -9,7 +9,6 @@
  *
  * TODO
  *  - use IANA UDP port number (when defined)
- *  - IPv6 (not in RFC)
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -42,6 +41,11 @@
 #include <net/inet_ecn.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/addrconf.h>
+#include <net/ip6_route.h>
+#include <net/ip6_tunnel.h>
+#endif
 
 #define VXLAN_VERSION	"0.1"
 
@@ -56,6 +60,7 @@
 #define VXLAN_VID_MASK	(VXLAN_N_VID - 1)
 /* IP header + UDP + VXLAN + Ethernet header */
 #define VXLAN_HEADROOM (20 + 8 + 8 + 14)
+#define VXLAN6_HEADROOM (40 + 8 + 8 + 14)
 
 #define VXLAN_FLAGS 0x08000000	/* struct vxlanhdr.vx_flags required value. */
 
@@ -81,9 +86,20 @@ struct vxlan_net {
 	struct hlist_head vni_list[VNI_HASH_SIZE];
 };
 
+struct vxlan_addr {
+	union {
+		struct sockaddr_in	sin;
+		struct sockaddr_in6	sin6;
+		struct sockaddr		sa;
+	} u;
+#define sin u.sin.sin_addr.s_addr
+#define sin6 u.sin6.sin6_addr
+#define family u.sa.sa_family
+};
+
 struct vxlan_rdst {
 	struct rcu_head		 rcu;
-	__be32			 remote_ip;
+	struct vxlan_addr	 remote_ip;
 	__be16			 remote_port;
 	u32			 remote_vni;
 	u32			 remote_ifindex;
@@ -106,8 +122,8 @@ struct vxlan_dev {
 	struct hlist_node hlist;
 	struct net_device *dev;
 	__u32		  vni;		/* virtual network id */
-	__be32	          gaddr;	/* multicast group */
-	__be32		  saddr;	/* source address */
+	struct vxlan_addr gaddr;	/* multicast group */
+	struct vxlan_addr saddr;	/* source address */
 	unsigned int      link;		/* link to multicast over */
 	__u16		  port_min;	/* source port range */
 	__u16		  port_max;
@@ -130,6 +146,59 @@ struct vxlan_dev {
 #define VXLAN_F_L2MISS	0x08
 #define VXLAN_F_L3MISS	0x10
 
+static inline
+bool vxlan_addr_equal(const struct vxlan_addr *a, const struct vxlan_addr *b)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (a->family != b->family)
+		return false;
+	if (a->family == AF_INET6)
+		return ipv6_addr_equal(&a->sin6, &b->sin6);
+	else
+#endif
+		return a->sin == b->sin;
+}
+
+static inline bool vxlan_addr_any(const struct vxlan_addr *ipa)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (ipa->family == AF_INET6)
+		return ipv6_addr_any(&ipa->sin6);
+	else
+#endif
+		return ipa->sin == htonl(INADDR_ANY);
+}
+
+static int vxlan_nla_get_addr(struct vxlan_addr *ip, struct nlattr *nla)
+{
+	if (nla_len(nla) == sizeof(struct in6_addr)) {
+#if IS_ENABLED(CONFIG_IPV6)
+		nla_memcpy(&ip->sin6, nla, sizeof(struct in6_addr));
+		ip->family = AF_INET6;
+		return 0;
+#else
+		return -EAFNOSUPPORT;
+#endif
+	} else if (nla_len(nla) == sizeof(__be32)) {
+		ip->sin = nla_get_be32(nla);
+		ip->family = AF_INET;
+		return 0;
+	} else {
+		return -EAFNOSUPPORT;
+	}
+}
+
+static int vxlan_nla_put_addr(struct sk_buff *skb, int attr,
+			      const struct vxlan_addr *ip)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (ip->family == AF_INET6)
+		return nla_put(skb, attr, sizeof(struct in6_addr), &ip->sin6);
+	else
+#endif
+		return nla_put_be32(skb, attr, ip->sin);
+}
+
 /* salt for hash table */
 static u32 vxlan_salt __read_mostly;
 
@@ -176,7 +245,7 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
 
 	if (type == RTM_GETNEIGH) {
 		ndm->ndm_family	= AF_INET;
-		send_ip = rdst->remote_ip != htonl(INADDR_ANY);
+		send_ip = !vxlan_addr_any(&rdst->remote_ip);
 		send_eth = !is_zero_ether_addr(fdb->eth_addr);
 	} else
 		ndm->ndm_family	= AF_BRIDGE;
@@ -188,7 +257,7 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
 	if (send_eth && nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->eth_addr))
 		goto nla_put_failure;
 
-	if (send_ip && nla_put_be32(skb, NDA_DST, rdst->remote_ip))
+	if (send_ip && vxlan_nla_put_addr(skb, NDA_DST, &rdst->remote_ip))
 		goto nla_put_failure;
 
 	if (rdst->remote_port && rdst->remote_port != vxlan_port &&
@@ -220,7 +289,7 @@ static inline size_t vxlan_nlmsg_size(void)
 {
 	return NLMSG_ALIGN(sizeof(struct ndmsg))
 		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
-		+ nla_total_size(sizeof(__be32)) /* NDA_DST */
+		+ nla_total_size(sizeof(struct in6_addr)) /* NDA_DST */
 		+ nla_total_size(sizeof(__be32)) /* NDA_PORT */
 		+ nla_total_size(sizeof(__be32)) /* NDA_VNI */
 		+ nla_total_size(sizeof(__u32)) /* NDA_IFINDEX */
@@ -253,14 +322,14 @@ errout:
 		rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 }
 
-static void vxlan_ip_miss(struct net_device *dev, __be32 ipa)
+static void vxlan_ip_miss(struct net_device *dev, struct vxlan_addr *ipa)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_fdb f;
 
 	memset(&f, 0, sizeof f);
 	f.state = NUD_STALE;
-	f.remote.remote_ip = ipa; /* goes to NDA_DST */
+	f.remote.remote_ip = *ipa; /* goes to NDA_DST */
 	f.remote.remote_vni = VXLAN_N_VID;
 
 	vxlan_fdb_notify(vxlan, &f, RTM_GETNEIGH);
@@ -315,14 +384,14 @@ static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan,
 }
 
 /* Add/update destinations for multicast */
-static int vxlan_fdb_append(struct vxlan_fdb *f,
-			    __be32 ip, __u32 port, __u32 vni, __u32 ifindex)
+static int vxlan_fdb_append(struct vxlan_fdb *f, struct vxlan_addr *ip,
+			    __u32 port, __u32 vni, __u32 ifindex)
 {
 	struct vxlan_rdst *rd_prev, *rd;
 
 	rd_prev = NULL;
 	for (rd = &f->remote; rd; rd = rd->remote_next) {
-		if (rd->remote_ip == ip &&
+		if (vxlan_addr_equal(&rd->remote_ip, ip) &&
 		    rd->remote_port == port &&
 		    rd->remote_vni == vni &&
 		    rd->remote_ifindex == ifindex)
@@ -332,7 +401,7 @@ static int vxlan_fdb_append(struct vxlan_fdb *f,
 	rd = kmalloc(sizeof(*rd), GFP_ATOMIC);
 	if (rd == NULL)
 		return -ENOBUFS;
-	rd->remote_ip = ip;
+	rd->remote_ip = *ip;
 	rd->remote_port = port;
 	rd->remote_vni = vni;
 	rd->remote_ifindex = ifindex;
@@ -343,7 +412,7 @@ static int vxlan_fdb_append(struct vxlan_fdb *f,
 
 /* Add new entry to forwarding table -- assumes lock held */
 static int vxlan_fdb_create(struct vxlan_dev *vxlan,
-			    const u8 *mac, __be32 ip,
+			    const u8 *mac, struct vxlan_addr *ip,
 			    __u16 state, __u16 flags,
 			    __u32 port, __u32 vni, __u32 ifindex)
 {
@@ -383,7 +452,7 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan,
 			return -ENOMEM;
 
 		notify = 1;
-		f->remote.remote_ip = ip;
+		f->remote.remote_ip = *ip;
 		f->remote.remote_port = port;
 		f->remote.remote_vni = vni;
 		f->remote.remote_ifindex = ifindex;
@@ -435,7 +504,7 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct net *net = dev_net(vxlan->dev);
-	__be32 ip;
+	struct vxlan_addr ip;
 	u32 port, vni, ifindex;
 	int err;
 
@@ -448,10 +517,9 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 	if (tb[NDA_DST] == NULL)
 		return -EINVAL;
 
-	if (nla_len(tb[NDA_DST]) != sizeof(__be32))
-		return -EAFNOSUPPORT;
-
-	ip = nla_get_be32(tb[NDA_DST]);
+	err = vxlan_nla_get_addr(&ip, tb[NDA_DST]);
+	if (err)
+		return err;
 
 	if (tb[NDA_PORT]) {
 		if (nla_len(tb[NDA_PORT]) != sizeof(u32))
@@ -481,7 +549,7 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		ifindex = 0;
 
 	spin_lock_bh(&vxlan->hash_lock);
-	err = vxlan_fdb_create(vxlan, addr, ip, ndm->ndm_state, flags, port,
+	err = vxlan_fdb_create(vxlan, addr, &ip, ndm->ndm_state, flags, port,
 		vni, ifindex);
 	spin_unlock_bh(&vxlan->hash_lock);
 
@@ -545,7 +613,7 @@ skip:
  * and Tunnel endpoint.
  */
 static void vxlan_snoop(struct net_device *dev,
-			__be32 src_ip, const u8 *src_mac)
+			struct vxlan_addr *src_ip, const u8 *src_mac)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_fdb *f;
@@ -554,7 +622,7 @@ static void vxlan_snoop(struct net_device *dev,
 	f = vxlan_find_mac(vxlan, src_mac);
 	if (likely(f)) {
 		f->used = jiffies;
-		if (likely(f->remote.remote_ip == src_ip))
+		if (likely(vxlan_addr_equal(&f->remote.remote_ip, src_ip)))
 			return;
 
 		if (net_ratelimit())
@@ -562,7 +630,7 @@ static void vxlan_snoop(struct net_device *dev,
 				    "%pM migrated from %pI4 to %pI4\n",
 				    src_mac, &f->remote.remote_ip, &src_ip);
 
-		f->remote.remote_ip = src_ip;
+		f->remote.remote_ip = *src_ip;
 		f->updated = jiffies;
 	} else {
 		/* learned new entry */
@@ -591,7 +659,7 @@ static bool vxlan_group_used(struct vxlan_net *vn,
 			if (!netif_running(vxlan->dev))
 				continue;
 
-			if (vxlan->gaddr == this->gaddr)
+			if (vxlan_addr_equal(&vxlan->gaddr, &this->gaddr))
 				return true;
 		}
 
@@ -605,7 +673,7 @@ static int vxlan_join_group(struct net_device *dev)
 	struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
 	struct sock *sk = vn->sock->sk;
 	struct ip_mreqn mreq = {
-		.imr_multiaddr.s_addr	= vxlan->gaddr,
+		.imr_multiaddr.s_addr	= vxlan->gaddr.sin,
 		.imr_ifindex		= vxlan->link,
 	};
 	int err;
@@ -617,7 +685,12 @@ static int vxlan_join_group(struct net_device *dev)
 	/* Need to drop RTNL to call multicast join */
 	rtnl_unlock();
 	lock_sock(sk);
-	err = ip_mc_join_group(sk, &mreq);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (vxlan->gaddr.family == AF_INET6)
+		err = ipv6_sock_mc_join(sk, vxlan->link, &vxlan->gaddr.sin6);
+	else
+#endif
+		err = ip_mc_join_group(sk, &mreq);
 	release_sock(sk);
 	rtnl_lock();
 
@@ -633,7 +706,7 @@ static int vxlan_leave_group(struct net_device *dev)
 	int err = 0;
 	struct sock *sk = vn->sock->sk;
 	struct ip_mreqn mreq = {
-		.imr_multiaddr.s_addr	= vxlan->gaddr,
+		.imr_multiaddr.s_addr	= vxlan->gaddr.sin,
 		.imr_ifindex		= vxlan->link,
 	};
 
@@ -644,7 +717,12 @@ static int vxlan_leave_group(struct net_device *dev)
 	/* Need to drop RTNL to call multicast leave */
 	rtnl_unlock();
 	lock_sock(sk);
-	err = ip_mc_leave_group(sk, &mreq);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (vxlan->gaddr.family == AF_INET6)
+		err = ipv6_sock_mc_drop(sk, vxlan->link, &vxlan->gaddr.sin6);
+	else
+#endif
+		err = ip_mc_leave_group(sk, &mreq);
 	release_sock(sk);
 	rtnl_lock();
 
@@ -654,12 +732,16 @@ static int vxlan_leave_group(struct net_device *dev)
 /* Callback from net/ipv4/udp.c to receive packets */
 static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 {
-	struct iphdr *oip;
+	struct iphdr *oip = NULL;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct ipv6hdr *oip6 = NULL;
+#endif
 	struct vxlanhdr *vxh;
 	struct vxlan_dev *vxlan;
 	struct pcpu_tstats *stats;
+	struct vxlan_addr src_ip;
 	__u32 vni;
-	int err;
+	int err = 0;
 
 	/* pop off outer UDP header */
 	__skb_pull(skb, sizeof(struct udphdr));
@@ -696,7 +778,13 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	skb_reset_mac_header(skb);
 
 	/* Re-examine inner Ethernet packet */
-	oip = ip_hdr(skb);
+	if (skb->protocol == htons(ETH_P_IP))
+		oip = ip_hdr(skb);
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		oip6 = ipv6_hdr(skb);
+#endif
+
 	skb->protocol = eth_type_trans(skb, vxlan->dev);
 
 	/* Ignore packet loops (and multicast echo) */
@@ -704,8 +792,19 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 			       vxlan->dev->dev_addr) == 0)
 		goto drop;
 
-	if (vxlan->flags & VXLAN_F_LEARN)
-		vxlan_snoop(skb->dev, oip->saddr, eth_hdr(skb)->h_source);
+	if (vxlan->flags & VXLAN_F_LEARN) {
+		if (oip) {
+			src_ip.sin = oip->saddr;
+			src_ip.family = AF_INET;
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		if (oip6) {
+			src_ip.sin6 = oip6->saddr;
+			src_ip.family = AF_INET6;
+		}
+#endif
+		vxlan_snoop(skb->dev, &src_ip, eth_hdr(skb)->h_source);
+	}
 
 	__skb_tunnel_rx(skb, vxlan->dev);
 	skb_reset_network_header(skb);
@@ -721,11 +820,24 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 
 	skb->encapsulation = 0;
 
-	err = IP_ECN_decapsulate(oip, skb);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (oip6)
+		err = IP6_ECN_decapsulate(oip6, skb);
+#endif
+	if (oip)
+		err = IP_ECN_decapsulate(oip, skb);
+
 	if (unlikely(err)) {
-		if (log_ecn_error)
-			net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
-					     &oip->saddr, oip->tos);
+		if (log_ecn_error) {
+#if IS_ENABLED(CONFIG_IPV6)
+			if (oip6)
+				net_info_ratelimited("non-ECT from %pI6\n",
+					     &oip6->saddr);
+#endif
+			if (oip)
+				net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
+						     &oip->saddr, oip->tos);
+		}
 		if (err > 1) {
 			++vxlan->dev->stats.rx_frame_errors;
 			++vxlan->dev->stats.rx_errors;
@@ -760,6 +872,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb)
 	u8 *arpptr, *sha;
 	__be32 sip, tip;
 	struct neighbour *n;
+	struct vxlan_addr ipa;
 
 	if (dev->flags & IFF_NOARP)
 		goto out;
@@ -801,7 +914,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb)
 		}
 
 		f = vxlan_find_mac(vxlan, n->ha);
-		if (f && f->remote.remote_ip == htonl(INADDR_ANY)) {
+		if (f && vxlan_addr_any(&f->remote.remote_ip)) {
 			/* bridge-local neighbor */
 			neigh_release(n);
 			goto out;
@@ -819,8 +932,11 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb)
 
 		if (netif_rx_ni(reply) == NET_RX_DROP)
 			dev->stats.rx_dropped++;
-	} else if (vxlan->flags & VXLAN_F_L3MISS)
-		vxlan_ip_miss(dev, tip);
+	} else if (vxlan->flags & VXLAN_F_L3MISS) {
+		ipa.sin = tip;
+		ipa.family = AF_INET;
+		vxlan_ip_miss(dev, &ipa);
+	}
 out:
 	consume_skb(skb);
 	return NETDEV_TX_OK;
@@ -842,6 +958,14 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
 			return false;
 		pip = ip_hdr(skb);
 		n = neigh_lookup(&arp_tbl, &pip->daddr, dev);
+		if (!n && vxlan->flags & VXLAN_F_L3MISS) {
+			struct vxlan_addr ipa;
+			ipa.sin = pip->daddr;
+			ipa.family = AF_INET;
+			vxlan_ip_miss(dev, &ipa);
+			return false;
+		}
+
 		break;
 	default:
 		return false;
@@ -858,8 +982,8 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
 		}
 		neigh_release(n);
 		return diff;
-	} else if (vxlan->flags & VXLAN_F_L3MISS)
-		vxlan_ip_miss(dev, pip->daddr);
+	}
+
 	return false;
 }
 
@@ -869,7 +993,8 @@ static void vxlan_sock_free(struct sk_buff *skb)
 }
 
 /* On transmit, associate with the tunnel socket */
-static void vxlan_set_owner(struct net_device *dev, struct sk_buff *skb)
+static inline void vxlan_set_owner(struct net_device *dev,
+				   struct sk_buff *skb)
 {
 	struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
 	struct sock *sk = vn->sock->sk;
@@ -917,23 +1042,30 @@ static netdev_tx_t vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct rtable *rt;
-	const struct iphdr *old_iph;
+	const struct iphdr *old_iph = NULL;
 	struct iphdr *iph;
 	struct vxlanhdr *vxh;
 	struct udphdr *uh;
 	struct flowi4 fl4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct flowi6 fl6;
+	struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
+	struct sock *sk = vn->sock->sk;
+	struct ipv6hdr *ip6h;
+#endif
 	unsigned int pkt_len = skb->len;
-	__be32 dst;
-	__u16 src_port, dst_port;
+	const struct vxlan_addr *dst;
+	struct dst_entry *ndst = NULL;
+	__u16 src_port = 0, dst_port;
         u32 vni;
 	__be16 df = 0;
 	__u8 tos, ttl;
 
 	dst_port = rdst->remote_port ? rdst->remote_port : vxlan_port;
 	vni = rdst->remote_vni;
-	dst = rdst->remote_ip;
+	dst = &rdst->remote_ip;
 
-	if (!dst) {
+	if (vxlan_addr_any(dst)) {
 		if (did_rsc) {
 			__skb_pull(skb, skb_network_offset(skb));
 			skb->ip_summed = CHECKSUM_NONE;
@@ -961,47 +1093,86 @@ static netdev_tx_t vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		skb->encapsulation = 1;
 	}
 
-	/* Need space for new headers (invalidates iph ptr) */
-	if (skb_cow_head(skb, VXLAN_HEADROOM))
-		goto drop;
+	ttl = vxlan->ttl;
+	tos = vxlan->tos;
+	if (dst->family == AF_INET) {
+		/* Need space for new headers (invalidates iph ptr) */
+		if (skb_cow_head(skb, VXLAN_HEADROOM))
+			goto drop;
 
-	old_iph = ip_hdr(skb);
+		old_iph = ip_hdr(skb);
+		if (!ttl && IN_MULTICAST(ntohl(dst->sin)))
+			ttl = 1;
 
-	ttl = vxlan->ttl;
-	if (!ttl && IN_MULTICAST(ntohl(dst)))
-		ttl = 1;
+		if (tos == 1)
+			tos = ip_tunnel_get_dsfield(old_iph, skb);
 
-	tos = vxlan->tos;
-	if (tos == 1)
-		tos = ip_tunnel_get_dsfield(old_iph, skb);
-
-	src_port = vxlan_src_port(vxlan, skb);
-
-	memset(&fl4, 0, sizeof(fl4));
-	fl4.flowi4_oif = rdst->remote_ifindex;
-	fl4.flowi4_tos = RT_TOS(tos);
-	fl4.daddr = dst;
-	fl4.saddr = vxlan->saddr;
-
-	rt = ip_route_output_key(dev_net(dev), &fl4);
-	if (IS_ERR(rt)) {
-		netdev_dbg(dev, "no route to %pI4\n", &dst);
-		dev->stats.tx_carrier_errors++;
-		goto tx_error;
-	}
+		src_port = vxlan_src_port(vxlan, skb);
+
+		memset(&fl4, 0, sizeof(fl4));
+		fl4.flowi4_oif = rdst->remote_ifindex;
+		fl4.flowi4_tos = RT_TOS(tos);
+		fl4.daddr = dst->sin;
+		fl4.saddr = vxlan->saddr.sin;
+
+		rt = ip_route_output_key(dev_net(dev), &fl4);
+		if (IS_ERR(rt)) {
+			netdev_dbg(dev, "no route to %pI4\n", &dst->sin);
+			dev->stats.tx_carrier_errors++;
+			goto tx_error;
+		}
+
+		if (rt->dst.dev == dev) {
+			netdev_dbg(dev, "circular route to %pI4\n", &dst->sin);
+			ip_rt_put(rt);
+			dev->stats.collisions++;
+			goto tx_error;
+		}
+		ndst = &rt->dst;
+		memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	} else {
+#if IS_ENABLED(CONFIG_IPV6)
+		const struct ipv6hdr *old_iph6;
 
-	if (rt->dst.dev == dev) {
-		netdev_dbg(dev, "circular route to %pI4\n", &dst);
-		ip_rt_put(rt);
-		dev->stats.collisions++;
-		goto tx_error;
+		/* Need space for new headers (invalidates iph ptr) */
+		if (skb_cow_head(skb, VXLAN6_HEADROOM))
+			goto drop;
+
+		old_iph6 = ipv6_hdr(skb);
+		if (!ttl && ipv6_addr_is_multicast(&dst->sin6))
+			ttl = 1;
+
+		if (tos == 1)
+			tos = ipv6_get_dsfield(old_iph6);
+
+		src_port = vxlan_src_port(vxlan, skb);
+
+		memset(&fl6, 0, sizeof(fl6));
+		fl6.flowi6_oif = vxlan->link;
+		fl6.flowi6_tos = RT_TOS(tos);
+		fl6.daddr = dst->sin6;
+		fl6.saddr = vxlan->saddr.sin6;
+		fl6.flowi6_proto = skb->protocol;
+
+		if (ip6_dst_lookup(sk, &ndst, &fl6)) {
+			netdev_dbg(dev, "no route to %pI6\n", &dst->sin6);
+			dev->stats.tx_carrier_errors++;
+			goto tx_error;
+		}
+
+		if (ndst->dev == dev) {
+			netdev_dbg(dev, "circular route to %pI6\n", &dst->sin6);
+			dst_release(ndst);
+			dev->stats.collisions++;
+			goto tx_error;
+		}
+#endif
 	}
 
-	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
 			      IPSKB_REROUTED);
 	skb_dst_drop(skb);
-	skb_dst_set(skb, &rt->dst);
+	skb_dst_set(skb, ndst);
 
 	vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
 	vxh->vx_flags = htonl(VXLAN_FLAGS);
@@ -1017,27 +1188,55 @@ static netdev_tx_t vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 	uh->len = htons(skb->len);
 	uh->check = 0;
 
-	__skb_push(skb, sizeof(*iph));
-	skb_reset_network_header(skb);
-	iph		= ip_hdr(skb);
-	iph->version	= 4;
-	iph->ihl	= sizeof(struct iphdr) >> 2;
-	iph->frag_off	= df;
-	iph->protocol	= IPPROTO_UDP;
-	iph->tos	= ip_tunnel_ecn_encap(tos, old_iph, skb);
-	iph->daddr	= dst;
-	iph->saddr	= fl4.saddr;
-	iph->ttl	= ttl ? : ip4_dst_hoplimit(&rt->dst);
-	tunnel_ip_select_ident(skb, old_iph, &rt->dst);
-
-	nf_reset(skb);
+	if (dst->family == AF_INET) {
+		__skb_push(skb, sizeof(*iph));
+		skb_reset_network_header(skb);
+		iph		= ip_hdr(skb);
+		iph->version	= 4;
+		iph->ihl	= sizeof(struct iphdr) >> 2;
+		iph->frag_off	= df;
+		iph->protocol	= IPPROTO_UDP;
+		iph->tos	= ip_tunnel_ecn_encap(tos, old_iph, skb);
+		iph->daddr	= dst->sin;
+		iph->saddr	= fl4.saddr;
+		iph->ttl	= ttl ? : ip4_dst_hoplimit(ndst);
+		tunnel_ip_select_ident(skb, old_iph, ndst);
+	} else {
+#if IS_ENABLED(CONFIG_IPV6)
+		if (skb->ip_summed == CHECKSUM_PARTIAL) {
+			skb->csum_start = skb_transport_header(skb) - skb->head;
+			skb->csum_offset = offsetof(struct udphdr, check);
+		} else
+			uh->check = csum_ipv6_magic(&fl6.saddr, &fl6.daddr,
+						    skb->len, IPPROTO_UDP,
+						    csum_partial(uh, skb->len, 0));
+		__skb_push(skb, sizeof(*ip6h));
+		skb_reset_network_header(skb);
+		ip6h		  = ipv6_hdr(skb);
+		ip6h->version	  = 6;
+		ip6h->priority	  = 0;
+		ip6h->flow_lbl[0] = 0;
+		ip6h->flow_lbl[1] = 0;
+		ip6h->flow_lbl[2] = 0;
+		ip6h->payload_len = htons(skb->len);
+		ip6h->nexthdr     = IPPROTO_UDP;
+		ip6h->hop_limit   = ttl ? : ip6_dst_hoplimit(ndst);
+		ip6h->daddr	  = fl6.daddr;
+		ip6h->saddr	  = fl6.saddr;
+#endif
+	}
 
 	vxlan_set_owner(dev, skb);
 
 	if (handle_offloads(skb))
 		goto drop;
 
-	iptunnel_xmit(skb, dev);
+	if (dst->family == AF_INET)
+		iptunnel_xmit(skb, dev);
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		ip6tunnel_xmit(skb, dev);
+#endif
 	return NETDEV_TX_OK;
 
 drop:
@@ -1084,7 +1283,7 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 		group.remote_next = 0;
 		rdst0 = &group;
 
-		if (group.remote_ip == htonl(INADDR_ANY) &&
+		if (vxlan_addr_any(&group.remote_ip) &&
 		    (vxlan->flags & VXLAN_F_L2MISS) &&
 		    !is_multicast_ether_addr(eth->h_dest))
 			vxlan_fdb_miss(vxlan, eth->h_dest);
@@ -1162,7 +1361,7 @@ static int vxlan_open(struct net_device *dev)
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	int err;
 
-	if (vxlan->gaddr) {
+	if (!vxlan_addr_any(&vxlan->gaddr)) {
 		err = vxlan_join_group(dev);
 		if (err)
 			return err;
@@ -1196,7 +1395,7 @@ static int vxlan_stop(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 
-	if (vxlan->gaddr)
+	if (!vxlan_addr_any(&vxlan->gaddr))
 		vxlan_leave_group(dev);
 
 	del_timer_sync(&vxlan->age_timer);
@@ -1246,7 +1445,10 @@ static void vxlan_setup(struct net_device *dev)
 
 	eth_hw_addr_random(dev);
 	ether_setup(dev);
-	dev->hard_header_len = ETH_HLEN + VXLAN_HEADROOM;
+	if (vxlan->gaddr.family == AF_INET)
+		dev->hard_header_len = ETH_HLEN + VXLAN_HEADROOM;
+	else
+		dev->hard_header_len = ETH_HLEN + VXLAN6_HEADROOM;
 
 	dev->netdev_ops = &vxlan_netdev_ops;
 	dev->destructor = vxlan_free;
@@ -1283,8 +1485,10 @@ static void vxlan_setup(struct net_device *dev)
 static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = {
 	[IFLA_VXLAN_ID]		= { .type = NLA_U32 },
 	[IFLA_VXLAN_GROUP]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
+	[IFLA_VXLAN_GROUP6]	= { .len = sizeof(struct in6_addr) },
 	[IFLA_VXLAN_LINK]	= { .type = NLA_U32 },
 	[IFLA_VXLAN_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
+	[IFLA_VXLAN_LOCAL6]	= { .len = sizeof(struct in6_addr) },
 	[IFLA_VXLAN_TOS]	= { .type = NLA_U8 },
 	[IFLA_VXLAN_TTL]	= { .type = NLA_U8 },
 	[IFLA_VXLAN_LEARNING]	= { .type = NLA_U8 },
@@ -1326,6 +1530,17 @@ static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[])
 			pr_debug("group address is not IPv4 multicast\n");
 			return -EADDRNOTAVAIL;
 		}
+	} else if (data[IFLA_VXLAN_GROUP6]) {
+#if IS_ENABLED(CONFIG_IPV6)
+		struct in6_addr gaddr;
+		nla_memcpy(&gaddr, data[IFLA_VXLAN_GROUP6], sizeof(gaddr));
+		if (!ipv6_addr_is_multicast(&gaddr)) {
+			pr_debug("group address is not IPv6 multicast\n");
+			return -EADDRNOTAVAIL;
+		}
+#else
+		return -EPFNOSUPPORT;
+#endif
 	}
 
 	if (data[IFLA_VXLAN_PORT_RANGE]) {
@@ -1371,11 +1586,31 @@ static int vxlan_newlink(struct net *net, struct net_device *dev,
 	}
 	vxlan->vni = vni;
 
-	if (data[IFLA_VXLAN_GROUP])
-		vxlan->gaddr = nla_get_be32(data[IFLA_VXLAN_GROUP]);
+	if (data[IFLA_VXLAN_GROUP]) {
+		vxlan->gaddr.sin = nla_get_be32(data[IFLA_VXLAN_GROUP]);
+		vxlan->gaddr.family = AF_INET;
+	} else if (data[IFLA_VXLAN_GROUP6]) {
+#if IS_ENABLED(CONFIG_IPV6)
+		nla_memcpy(&vxlan->gaddr.sin6, data[IFLA_VXLAN_GROUP6],
+			   sizeof(struct in6_addr));
+		vxlan->gaddr.family = AF_INET6;
+#else
+		return -EPFNOSUPPORT;
+#endif
+	}
 
-	if (data[IFLA_VXLAN_LOCAL])
-		vxlan->saddr = nla_get_be32(data[IFLA_VXLAN_LOCAL]);
+	if (data[IFLA_VXLAN_LOCAL]) {
+		vxlan->saddr.sin = nla_get_be32(data[IFLA_VXLAN_LOCAL]);
+		vxlan->saddr.family = AF_INET;
+	} else if (data[IFLA_VXLAN_LOCAL6]) {
+#if IS_ENABLED(CONFIG_IPV6)
+		nla_memcpy(&vxlan->saddr.sin6, data[IFLA_VXLAN_LOCAL6],
+			   sizeof(struct in6_addr));
+		vxlan->saddr.family = AF_INET6;
+#else
+		return -EPFNOSUPPORT;
+#endif
+	}
 
 	if (data[IFLA_VXLAN_LINK] &&
 	    (vxlan->link = nla_get_u32(data[IFLA_VXLAN_LINK]))) {
@@ -1453,9 +1688,9 @@ static size_t vxlan_get_size(const struct net_device *dev)
 {
 
 	return nla_total_size(sizeof(__u32)) +	/* IFLA_VXLAN_ID */
-		nla_total_size(sizeof(__be32)) +/* IFLA_VXLAN_GROUP */
+		nla_total_size(sizeof(struct in6_addr)) + /* IFLA_VXLAN_GROUP{6} */
 		nla_total_size(sizeof(__u32)) +	/* IFLA_VXLAN_LINK */
-		nla_total_size(sizeof(__be32))+	/* IFLA_VXLAN_LOCAL */
+		nla_total_size(sizeof(struct in6_addr)) + /* IFLA_VXLAN_LOCAL{6} */
 		nla_total_size(sizeof(__u8)) +	/* IFLA_VXLAN_TTL */
 		nla_total_size(sizeof(__u8)) +	/* IFLA_VXLAN_TOS */
 		nla_total_size(sizeof(__u8)) +	/* IFLA_VXLAN_LEARNING */
@@ -1480,14 +1715,34 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	if (nla_put_u32(skb, IFLA_VXLAN_ID, vxlan->vni))
 		goto nla_put_failure;
 
-	if (vxlan->gaddr && nla_put_be32(skb, IFLA_VXLAN_GROUP, vxlan->gaddr))
-		goto nla_put_failure;
+	if (!vxlan_addr_any(&vxlan->gaddr)) {
+		if (vxlan->gaddr.family == AF_INET) {
+			if (nla_put_be32(skb, IFLA_VXLAN_GROUP, vxlan->gaddr.sin))
+				goto nla_put_failure;
+		} else {
+#if IS_ENABLED(CONFIG_IPV6)
+			if (nla_put(skb, IFLA_VXLAN_GROUP6, sizeof(struct in6_addr),
+				    &vxlan->gaddr.sin6))
+				goto nla_put_failure;
+#endif
+		}
+	}
 
 	if (vxlan->link && nla_put_u32(skb, IFLA_VXLAN_LINK, vxlan->link))
 		goto nla_put_failure;
 
-	if (vxlan->saddr && nla_put_be32(skb, IFLA_VXLAN_LOCAL, vxlan->saddr))
-		goto nla_put_failure;
+	if (!vxlan_addr_any(&vxlan->saddr)) {
+		if (vxlan->saddr.family == AF_INET) {
+			if (nla_put_be32(skb, IFLA_VXLAN_LOCAL, vxlan->saddr.sin))
+				goto nla_put_failure;
+		} else {
+#if IS_ENABLED(CONFIG_IPV6)
+			if (nla_put(skb, IFLA_VXLAN_LOCAL6, sizeof(struct in6_addr),
+				    &vxlan->saddr.sin6))
+				goto nla_put_failure;
+#endif
+		}
+	}
 
 	if (nla_put_u8(skb, IFLA_VXLAN_TTL, vxlan->ttl) ||
 	    nla_put_u8(skb, IFLA_VXLAN_TOS, vxlan->tos) ||
@@ -1526,38 +1781,82 @@ static struct rtnl_link_ops vxlan_link_ops __read_mostly = {
 	.fill_info	= vxlan_fill_info,
 };
 
-static __net_init int vxlan_init_net(struct net *net)
+/* Create UDP socket for encapsulation receive. AF_INET6 socket
+ * could be used for both IPv4 and IPv6 communications.
+ */
+#if IS_ENABLED(CONFIG_IPV6)
+static __net_init int create_sock(struct net *net, struct sock **sk)
+{
+	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+	struct sockaddr_in6 vxlan_addr = {
+		.sin6_family = AF_INET6,
+		.sin6_port = htons(vxlan_port),
+	};
+	int rc;
+
+	rc = sock_create_kern(AF_INET6, SOCK_DGRAM, IPPROTO_UDP, &vn->sock);
+	if (rc < 0) {
+		pr_debug("UDP socket create failed\n");
+		return rc;
+	}
+	/* Put in proper namespace */
+	*sk = vn->sock->sk;
+	sk_change_net(*sk, net);
+
+	rc = kernel_bind(vn->sock, (struct sockaddr *)&vxlan_addr,
+			 sizeof(struct sockaddr_in6));
+	if (rc < 0) {
+		pr_debug("bind for UDP socket %pI6:%u (%d)\n",
+			 &vxlan_addr.sin6_addr, ntohs(vxlan_addr.sin6_port), rc);
+		sk_release_kernel(*sk);
+		vn->sock = NULL;
+		return rc;
+	}
+	return 0;
+}
+#else
+static __net_init int create_sock(struct net *net, struct sock **sk)
 {
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
-	struct sock *sk;
 	struct sockaddr_in vxlan_addr = {
 		.sin_family = AF_INET,
+		.sin_port = htons(vxlan_port),
 		.sin_addr.s_addr = htonl(INADDR_ANY),
 	};
 	int rc;
-	unsigned h;
 
-	/* Create UDP socket for encapsulation receive. */
 	rc = sock_create_kern(AF_INET, SOCK_DGRAM, IPPROTO_UDP, &vn->sock);
 	if (rc < 0) {
 		pr_debug("UDP socket create failed\n");
 		return rc;
 	}
 	/* Put in proper namespace */
-	sk = vn->sock->sk;
-	sk_change_net(sk, net);
-
-	vxlan_addr.sin_port = htons(vxlan_port);
+	*sk = vn->sock->sk;
+	sk_change_net(*sk, net);
 
-	rc = kernel_bind(vn->sock, (struct sockaddr *) &vxlan_addr,
-			 sizeof(vxlan_addr));
+	rc = kernel_bind(vn->sock, (struct sockaddr *)&vxlan_addr,
+			 sizeof(struct sockaddr_in));
 	if (rc < 0) {
 		pr_debug("bind for UDP socket %pI4:%u (%d)\n",
 			 &vxlan_addr.sin_addr, ntohs(vxlan_addr.sin_port), rc);
-		sk_release_kernel(sk);
+		sk_release_kernel(*sk);
 		vn->sock = NULL;
 		return rc;
 	}
+	return 0;
+}
+#endif
+
+static __net_init int vxlan_init_net(struct net *net)
+{
+	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+	struct sock *sk;
+	int rc;
+	unsigned h;
+
+	rc = create_sock(net, &sk);
+	if (rc < 0)
+		return rc;
 
 	/* Disable multicast loopback */
 	inet_sk(sk)->mc_loop = 0;
@@ -1566,6 +1865,9 @@ static __net_init int vxlan_init_net(struct net *net)
 	udp_sk(sk)->encap_type = 1;
 	udp_sk(sk)->encap_rcv = vxlan_udp_encap_recv;
 	udp_encap_enable();
+#if IS_ENABLED(CONFIG_IPV6)
+	udpv6_encap_enable();
+#endif
 
 	for (h = 0; h < VNI_HASH_SIZE; ++h)
 		INIT_HLIST_HEAD(&vn->vni_list[h]);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index c4edfe1..0eee00f 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -308,6 +308,8 @@ enum {
 	IFLA_VXLAN_RSC,
 	IFLA_VXLAN_L2MISS,
 	IFLA_VXLAN_L3MISS,
+	IFLA_VXLAN_GROUP6,
+	IFLA_VXLAN_LOCAL6,
 	__IFLA_VXLAN_MAX
 };
 #define IFLA_VXLAN_MAX	(__IFLA_VXLAN_MAX - 1)
-- 
1.7.7.6