1 files changed, 794 insertions, 196 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 7a7829e839c2..761a53c6a89a 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1,13 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	Linux NET3:	GRE over IP protocol decoder.
  *
  *	Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
- *
- *	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.
- *
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -33,6 +28,7 @@
 #include <linux/etherdevice.h>
 #include <linux/if_ether.h>
 
+#include <net/flow.h>
 #include <net/sock.h>
 #include <net/ip.h>
 #include <net/icmp.h>
@@ -48,6 +44,7 @@
 #include <net/rtnetlink.h>
 #include <net/gre.h>
 #include <net/dst_metadata.h>
+#include <net/erspan.h>
 
 /*
    Problems & solutions
@@ -111,13 +108,19 @@ module_param(log_ecn_error, bool, 0644);
 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 
 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
+static const struct header_ops ipgre_header_ops;
+
 static int ipgre_tunnel_init(struct net_device *dev);
+static void erspan_build_header(struct sk_buff *skb,
+				u32 id, u32 index,
+				bool truncate, bool is_ipv4);
 
 static unsigned int ipgre_net_id __read_mostly;
 static unsigned int gre_tap_net_id __read_mostly;
+static unsigned int erspan_net_id __read_mostly;
 
-static void ipgre_err(struct sk_buff *skb, u32 info,
-		      const struct tnl_ptk_info *tpi)
+static int ipgre_err(struct sk_buff *skb, u32 info,
+		     const struct tnl_ptk_info *tpi)
 {
 
 	/* All the routers (except for Linux) return only
@@ -138,20 +141,34 @@ static void ipgre_err(struct sk_buff *skb, u32 info,
 	const struct iphdr *iph;
 	const int type = icmp_hdr(skb)->type;
 	const int code = icmp_hdr(skb)->code;
-	unsigned int data_len = 0;
 	struct ip_tunnel *t;
 
+	if (tpi->proto == htons(ETH_P_TEB))
+		itn = net_generic(net, gre_tap_net_id);
+	else if (tpi->proto == htons(ETH_P_ERSPAN) ||
+		 tpi->proto == htons(ETH_P_ERSPAN2))
+		itn = net_generic(net, erspan_net_id);
+	else
+		itn = net_generic(net, ipgre_net_id);
+
+	iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
+	t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+			     iph->daddr, iph->saddr, tpi->key);
+
+	if (!t)
+		return -ENOENT;
+
 	switch (type) {
 	default:
 	case ICMP_PARAMETERPROB:
-		return;
+		return 0;
 
 	case ICMP_DEST_UNREACH:
 		switch (code) {
 		case ICMP_SR_FAILED:
 		case ICMP_PORT_UNREACH:
 			/* Impossible event. */
-			return;
+			return 0;
 		default:
 			/* All others are translated to HOST_UNREACH.
 			   rfc2003 contains "deep thoughts" about NET_UNREACH,
@@ -163,45 +180,40 @@ static void ipgre_err(struct sk_buff *skb, u32 info,
 
 	case ICMP_TIME_EXCEEDED:
 		if (code != ICMP_EXC_TTL)
-			return;
-		data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
+			return 0;
 		break;
 
 	case ICMP_REDIRECT:
 		break;
 	}
 
-	if (tpi->proto == htons(ETH_P_TEB))
-		itn = net_generic(net, gre_tap_net_id);
-	else
-		itn = net_generic(net, ipgre_net_id);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (tpi->proto == htons(ETH_P_IPV6)) {
+		unsigned int data_len = 0;
 
-	iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
-	t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
-			     iph->daddr, iph->saddr, tpi->key);
+		if (type == ICMP_TIME_EXCEEDED)
+			data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
 
-	if (!t)
-		return;
-
-#if IS_ENABLED(CONFIG_IPV6)
-       if (tpi->proto == htons(ETH_P_IPV6) &&
-           !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
-				       type, data_len))
-               return;
+		if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
+						type, data_len))
+			return 0;
+	}
 #endif
 
 	if (t->parms.iph.daddr == 0 ||
 	    ipv4_is_multicast(t->parms.iph.daddr))
-		return;
+		return 0;
 
 	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
-		return;
+		return 0;
 
 	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 		t->err_count++;
 	else
 		t->err_count = 1;
 	t->err_time = jiffies;
+
+	return 0;
 }
 
 static void gre_err(struct sk_buff *skb, u32 info)
@@ -224,28 +236,131 @@ static void gre_err(struct sk_buff *skb, u32 info)
 	const int type = icmp_hdr(skb)->type;
 	const int code = icmp_hdr(skb)->code;
 	struct tnl_ptk_info tpi;
-	bool csum_err = false;
 
-	if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP),
-			     iph->ihl * 4) < 0) {
-		if (!csum_err)		/* ignore csum errors. */
-			return;
-	}
+	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
+			     iph->ihl * 4) < 0)
+		return;
 
 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
-				 skb->dev->ifindex, 0, IPPROTO_GRE, 0);
+				 skb->dev->ifindex, IPPROTO_GRE);
 		return;
 	}
 	if (type == ICMP_REDIRECT) {
-		ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0,
-			      IPPROTO_GRE, 0);
+		ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
+			      IPPROTO_GRE);
 		return;
 	}
 
 	ipgre_err(skb, info, &tpi);
 }
 
+static bool is_erspan_type1(int gre_hdr_len)
+{
+	/* Both ERSPAN type I (version 0) and type II (version 1) use
+	 * protocol 0x88BE, but the type I has only 4-byte GRE header,
+	 * while type II has 8-byte.
+	 */
+	return gre_hdr_len == 4;
+}
+
+static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
+		      int gre_hdr_len)
+{
+	struct net *net = dev_net(skb->dev);
+	struct metadata_dst *tun_dst = NULL;
+	struct erspan_base_hdr *ershdr;
+	IP_TUNNEL_DECLARE_FLAGS(flags);
+	struct ip_tunnel_net *itn;
+	struct ip_tunnel *tunnel;
+	const struct iphdr *iph;
+	struct erspan_md2 *md2;
+	int ver;
+	int len;
+
+	ip_tunnel_flags_copy(flags, tpi->flags);
+
+	itn = net_generic(net, erspan_net_id);
+	iph = ip_hdr(skb);
+	if (is_erspan_type1(gre_hdr_len)) {
+		ver = 0;
+		__set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
+		tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags,
+					  iph->saddr, iph->daddr, 0);
+	} else {
+		if (unlikely(!pskb_may_pull(skb,
+					    gre_hdr_len + sizeof(*ershdr))))
+			return PACKET_REJECT;
+
+		ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
+		ver = ershdr->ver;
+		iph = ip_hdr(skb);
+		__set_bit(IP_TUNNEL_KEY_BIT, flags);
+		tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags,
+					  iph->saddr, iph->daddr, tpi->key);
+	}
+
+	if (tunnel) {
+		if (is_erspan_type1(gre_hdr_len))
+			len = gre_hdr_len;
+		else
+			len = gre_hdr_len + erspan_hdr_len(ver);
+
+		if (unlikely(!pskb_may_pull(skb, len)))
+			return PACKET_REJECT;
+
+		if (__iptunnel_pull_header(skb,
+					   len,
+					   htons(ETH_P_TEB),
+					   false, false) < 0)
+			goto drop;
+
+		if (tunnel->collect_md) {
+			struct erspan_metadata *pkt_md, *md;
+			struct ip_tunnel_info *info;
+			unsigned char *gh;
+			__be64 tun_id;
+
+			__set_bit(IP_TUNNEL_KEY_BIT, tpi->flags);
+			ip_tunnel_flags_copy(flags, tpi->flags);
+			tun_id = key32_to_tunnel_id(tpi->key);
+
+			tun_dst = ip_tun_rx_dst(skb, flags,
+						tun_id, sizeof(*md));
+			if (!tun_dst)
+				return PACKET_REJECT;
+
+			/* skb can be uncloned in __iptunnel_pull_header, so
+			 * old pkt_md is no longer valid and we need to reset
+			 * it
+			 */
+			gh = skb_network_header(skb) +
+			     skb_network_header_len(skb);
+			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
+							    sizeof(*ershdr));
+			md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
+			md->version = ver;
+			md2 = &md->u.md2;
+			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
+						       ERSPAN_V2_MDSIZE);
+
+			info = &tun_dst->u.tun_info;
+			__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
+				  info->key.tun_flags);
+			info->options_len = sizeof(*md);
+		}
+
+		skb_reset_mac_header(skb);
+		ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
+		return PACKET_RCVD;
+	}
+	return PACKET_REJECT;
+
+drop:
+	kfree_skb(skb);
+	return PACKET_RCVD;
+}
+
 static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
 		       struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
 {
@@ -258,19 +373,29 @@ static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
 				  iph->saddr, iph->daddr, tpi->key);
 
 	if (tunnel) {
+		const struct iphdr *tnl_params;
+
 		if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
 					   raw_proto, false) < 0)
 			goto drop;
 
-		if (tunnel->dev->type != ARPHRD_NONE)
+		/* Special case for ipgre_header_parse(), which expects the
+		 * mac_header to point to the outer IP header.
+		 */
+		if (tunnel->dev->header_ops == &ipgre_header_ops)
 			skb_pop_mac_header(skb);
 		else
 			skb_reset_mac_header(skb);
-		if (tunnel->collect_md) {
-			__be16 flags;
+
+		tnl_params = &tunnel->parms.iph;
+		if (tunnel->collect_md || tnl_params->daddr == 0) {
+			IP_TUNNEL_DECLARE_FLAGS(flags) = { };
 			__be64 tun_id;
 
-			flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
+			__set_bit(IP_TUNNEL_CSUM_BIT, flags);
+			__set_bit(IP_TUNNEL_KEY_BIT, flags);
+			ip_tunnel_flags_and(flags, tpi->flags, flags);
+
 			tun_id = key32_to_tunnel_id(tpi->key);
 			tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
 			if (!tun_dst)
@@ -328,9 +453,17 @@ static int gre_rcv(struct sk_buff *skb)
 	if (hdr_len < 0)
 		goto drop;
 
+	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
+		     tpi.proto == htons(ETH_P_ERSPAN2))) {
+		if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
+			return 0;
+		goto out;
+	}
+
 	if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
 		return 0;
 
+out:
 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 drop:
 	kfree_skb(skb);
@@ -342,14 +475,15 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
 		       __be16 proto)
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
+	IP_TUNNEL_DECLARE_FLAGS(flags);
 
-	if (tunnel->parms.o_flags & TUNNEL_SEQ)
-		tunnel->o_seqno++;
+	ip_tunnel_flags_copy(flags, tunnel->parms.o_flags);
 
 	/* Push GRE header. */
 	gre_build_header(skb, tunnel->tun_hlen,
-			 tunnel->parms.o_flags, proto, tunnel->parms.o_key,
-			 htonl(tunnel->o_seqno));
+			 flags, proto, tunnel->parms.o_key,
+			 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
+			 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
 
 	ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
 }
@@ -359,35 +493,62 @@ static int gre_handle_offloads(struct sk_buff *skb, bool csum)
 	return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 }
 
-static struct rtable *gre_get_rt(struct sk_buff *skb,
-				 struct net_device *dev,
-				 struct flowi4 *fl,
-				 const struct ip_tunnel_key *key)
+static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
+			__be16 proto)
 {
-	struct net *net = dev_net(dev);
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
+	struct ip_tunnel_info *tun_info;
+	const struct ip_tunnel_key *key;
+	int tunnel_hlen;
 
-	memset(fl, 0, sizeof(*fl));
-	fl->daddr = key->u.ipv4.dst;
-	fl->saddr = key->u.ipv4.src;
-	fl->flowi4_tos = RT_TOS(key->tos);
-	fl->flowi4_mark = skb->mark;
-	fl->flowi4_proto = IPPROTO_GRE;
+	tun_info = skb_tunnel_info(skb);
+	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
+		     ip_tunnel_info_af(tun_info) != AF_INET))
+		goto err_free_skb;
+
+	key = &tun_info->key;
+	tunnel_hlen = gre_calc_hlen(key->tun_flags);
+
+	if (skb_cow_head(skb, dev->needed_headroom))
+		goto err_free_skb;
+
+	/* Push Tunnel header. */
+	if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
+					      tunnel->parms.o_flags)))
+		goto err_free_skb;
+
+	__set_bit(IP_TUNNEL_CSUM_BIT, flags);
+	__set_bit(IP_TUNNEL_KEY_BIT, flags);
+	__set_bit(IP_TUNNEL_SEQ_BIT, flags);
+	ip_tunnel_flags_and(flags, tun_info->key.tun_flags, flags);
 
-	return ip_route_output_key(net, fl);
+	gre_build_header(skb, tunnel_hlen, flags, proto,
+			 tunnel_id_to_key32(tun_info->key.tun_id),
+			 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
+			 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
+
+	ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
+
+	return;
+
+err_free_skb:
+	kfree_skb(skb);
+	DEV_STATS_INC(dev, tx_dropped);
 }
 
-static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
-			__be16 proto)
+static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 {
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
 	struct ip_tunnel_info *tun_info;
 	const struct ip_tunnel_key *key;
-	struct rtable *rt = NULL;
-	struct flowi4 fl;
-	int min_headroom;
+	struct erspan_metadata *md;
+	bool truncate = false;
+	__be16 proto;
 	int tunnel_hlen;
-	__be16 df, flags;
-	bool use_cache;
-	int err;
+	int version;
+	int nhoff;
 
 	tun_info = skb_tunnel_info(skb);
 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
@@ -395,63 +556,88 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 		goto err_free_skb;
 
 	key = &tun_info->key;
-	use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
-	if (use_cache)
-		rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl.saddr);
-	if (!rt) {
-		rt = gre_get_rt(skb, dev, &fl, key);
-		if (IS_ERR(rt))
-				goto err_free_skb;
-		if (use_cache)
-			dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
-					  fl.saddr);
+	if (!test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags))
+		goto err_free_skb;
+	if (tun_info->options_len < sizeof(*md))
+		goto err_free_skb;
+	md = ip_tunnel_info_opts(tun_info);
+
+	/* ERSPAN has fixed 8 byte GRE header */
+	version = md->version;
+	tunnel_hlen = 8 + erspan_hdr_len(version);
+
+	if (skb_cow_head(skb, dev->needed_headroom))
+		goto err_free_skb;
+
+	if (gre_handle_offloads(skb, false))
+		goto err_free_skb;
+
+	if (skb->len > dev->mtu + dev->hard_header_len) {
+		if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
+			goto err_free_skb;
+		truncate = true;
 	}
 
-	tunnel_hlen = gre_calc_hlen(key->tun_flags);
+	nhoff = skb_network_offset(skb);
+	if (skb->protocol == htons(ETH_P_IP) &&
+	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
+		truncate = true;
+
+	if (skb->protocol == htons(ETH_P_IPV6)) {
+		int thoff;
 
-	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
-			+ tunnel_hlen + sizeof(struct iphdr);
-	if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
-		int head_delta = SKB_DATA_ALIGN(min_headroom -
-						skb_headroom(skb) +
-						16);
-		err = pskb_expand_head(skb, max_t(int, head_delta, 0),
-				       0, GFP_ATOMIC);
-		if (unlikely(err))
-			goto err_free_rt;
+		if (skb_transport_header_was_set(skb))
+			thoff = skb_transport_offset(skb);
+		else
+			thoff = nhoff + sizeof(struct ipv6hdr);
+		if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
+			truncate = true;
 	}
 
-	/* Push Tunnel header. */
-	if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
-		goto err_free_rt;
+	if (version == 1) {
+		erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
+				    ntohl(md->u.index), truncate, true);
+		proto = htons(ETH_P_ERSPAN);
+	} else if (version == 2) {
+		erspan_build_header_v2(skb,
+				       ntohl(tunnel_id_to_key32(key->tun_id)),
+				       md->u.md2.dir,
+				       get_hwid(&md->u.md2),
+				       truncate, true);
+		proto = htons(ETH_P_ERSPAN2);
+	} else {
+		goto err_free_skb;
+	}
 
-	flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);
-	gre_build_header(skb, tunnel_hlen, flags, proto,
-			 tunnel_id_to_key32(tun_info->key.tun_id), 0);
+	__set_bit(IP_TUNNEL_SEQ_BIT, flags);
+	gre_build_header(skb, 8, flags, proto, 0,
+			 htonl(atomic_fetch_inc(&tunnel->o_seqno)));
 
-	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ?  htons(IP_DF) : 0;
+	ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
 
-	iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE,
-		      key->tos, key->ttl, df, false);
 	return;
 
-err_free_rt:
-	ip_rt_put(rt);
 err_free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 }
 
 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 {
 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
+	const struct ip_tunnel_key *key;
 	struct rtable *rt;
 	struct flowi4 fl4;
 
 	if (ip_tunnel_info_af(info) != AF_INET)
 		return -EINVAL;
 
-	rt = gre_get_rt(skb, dev, &fl4, &info->key);
+	key = &info->key;
+	ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
+			    tunnel_id_to_key32(key->tun_id),
+			    key->tos & ~INET_ECN_MASK, dev_net(dev), 0,
+			    skb->mark, skb_get_hash(skb), key->flow_flags);
+	rt = ip_route_output_key(dev_net(dev), &fl4);
 	if (IS_ERR(rt))
 		return PTR_ERR(rt);
 
@@ -466,24 +652,32 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 	const struct iphdr *tnl_params;
 
+	if (!pskb_inet_may_pull(skb))
+		goto free_skb;
+
 	if (tunnel->collect_md) {
 		gre_fb_xmit(skb, dev, skb->protocol);
 		return NETDEV_TX_OK;
 	}
 
 	if (dev->header_ops) {
-		/* Need space for new headers */
-		if (skb_cow_head(skb, dev->needed_headroom -
-				      (tunnel->hlen + sizeof(struct iphdr))))
+		int pull_len = tunnel->hlen + sizeof(struct iphdr);
+
+		if (skb_cow_head(skb, 0))
+			goto free_skb;
+
+		if (!pskb_may_pull(skb, pull_len))
 			goto free_skb;
 
 		tnl_params = (const struct iphdr *)skb->data;
 
-		/* Pull skb since ip_tunnel_xmit() needs skb->data pointing
-		 * to gre header.
-		 */
-		skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
+		/* ip_tunnel_xmit() needs skb->data pointing to gre header. */
+		skb_pull(skb, pull_len);
 		skb_reset_mac_header(skb);
+
+		if (skb->ip_summed == CHECKSUM_PARTIAL &&
+		    skb_checksum_start(skb) < skb->data)
+			goto free_skb;
 	} else {
 		if (skb_cow_head(skb, dev->needed_headroom))
 			goto free_skb;
@@ -491,7 +685,8 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 		tnl_params = &tunnel->parms.iph;
 	}
 
-	if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
+	if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
+					      tunnel->parms.o_flags)))
 		goto free_skb;
 
 	__gre_xmit(skb, dev, tnl_params, skb->protocol);
@@ -499,7 +694,62 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 
 free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
+	return NETDEV_TX_OK;
+}
+
+static netdev_tx_t erspan_xmit(struct sk_buff *skb,
+			       struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	bool truncate = false;
+	__be16 proto;
+
+	if (!pskb_inet_may_pull(skb))
+		goto free_skb;
+
+	if (tunnel->collect_md) {
+		erspan_fb_xmit(skb, dev);
+		return NETDEV_TX_OK;
+	}
+
+	if (gre_handle_offloads(skb, false))
+		goto free_skb;
+
+	if (skb_cow_head(skb, dev->needed_headroom))
+		goto free_skb;
+
+	if (skb->len > dev->mtu + dev->hard_header_len) {
+		if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
+			goto free_skb;
+		truncate = true;
+	}
+
+	/* Push ERSPAN header */
+	if (tunnel->erspan_ver == 0) {
+		proto = htons(ETH_P_ERSPAN);
+		__clear_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags);
+	} else if (tunnel->erspan_ver == 1) {
+		erspan_build_header(skb, ntohl(tunnel->parms.o_key),
+				    tunnel->index,
+				    truncate, true);
+		proto = htons(ETH_P_ERSPAN);
+	} else if (tunnel->erspan_ver == 2) {
+		erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
+				       tunnel->dir, tunnel->hwid,
+				       truncate, true);
+		proto = htons(ETH_P_ERSPAN2);
+	} else {
+		goto free_skb;
+	}
+
+	__clear_bit(IP_TUNNEL_KEY_BIT, tunnel->parms.o_flags);
+	__gre_xmit(skb, dev, &tunnel->parms.iph, proto);
+	return NETDEV_TX_OK;
+
+free_skb:
+	kfree_skb(skb);
+	DEV_STATS_INC(dev, tx_dropped);
 	return NETDEV_TX_OK;
 }
 
@@ -508,12 +758,16 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 
+	if (!pskb_inet_may_pull(skb))
+		goto free_skb;
+
 	if (tunnel->collect_md) {
 		gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
 		return NETDEV_TX_OK;
 	}
 
-	if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
+	if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
+					      tunnel->parms.o_flags)))
 		goto free_skb;
 
 	if (skb_cow_head(skb, dev->needed_headroom))
@@ -524,36 +778,82 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 
 free_skb:
 	kfree_skb(skb);
-	dev->stats.tx_dropped++;
+	DEV_STATS_INC(dev, tx_dropped);
 	return NETDEV_TX_OK;
 }
 
-static int ipgre_tunnel_ioctl(struct net_device *dev,
-			      struct ifreq *ifr, int cmd)
+static void ipgre_link_update(struct net_device *dev, bool set_mtu)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	int len;
+
+	len = tunnel->tun_hlen;
+	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
+	len = tunnel->tun_hlen - len;
+	tunnel->hlen = tunnel->hlen + len;
+
+	if (dev->header_ops)
+		dev->hard_header_len += len;
+	else
+		dev->needed_headroom += len;
+
+	if (set_mtu)
+		WRITE_ONCE(dev->mtu, max_t(int, dev->mtu - len, 68));
+
+	if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags) ||
+	    (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&
+	     tunnel->encap.type != TUNNEL_ENCAP_NONE)) {
+		dev->features &= ~NETIF_F_GSO_SOFTWARE;
+		dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
+	} else {
+		dev->features |= NETIF_F_GSO_SOFTWARE;
+		dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+	}
+}
+
+static int ipgre_tunnel_ctl(struct net_device *dev,
+			    struct ip_tunnel_parm_kern *p,
+			    int cmd)
 {
+	__be16 i_flags, o_flags;
 	int err;
-	struct ip_tunnel_parm p;
 
-	if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
-		return -EFAULT;
+	if (!ip_tunnel_flags_is_be16_compat(p->i_flags) ||
+	    !ip_tunnel_flags_is_be16_compat(p->o_flags))
+		return -EOVERFLOW;
+
+	i_flags = ip_tunnel_flags_to_be16(p->i_flags);
+	o_flags = ip_tunnel_flags_to_be16(p->o_flags);
+
 	if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
-		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
-		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
-		    ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
+		if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
+		    p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
+		    ((i_flags | o_flags) & (GRE_VERSION | GRE_ROUTING)))
 			return -EINVAL;
 	}
-	p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
-	p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
 
-	err = ip_tunnel_ioctl(dev, &p, cmd);
+	gre_flags_to_tnl_flags(p->i_flags, i_flags);
+	gre_flags_to_tnl_flags(p->o_flags, o_flags);
+
+	err = ip_tunnel_ctl(dev, p, cmd);
 	if (err)
 		return err;
 
-	p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags);
-	p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags);
+	if (cmd == SIOCCHGTUNNEL) {
+		struct ip_tunnel *t = netdev_priv(dev);
+
+		ip_tunnel_flags_copy(t->parms.i_flags, p->i_flags);
+		ip_tunnel_flags_copy(t->parms.o_flags, p->o_flags);
+
+		if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
+			ipgre_link_update(dev, true);
+	}
+
+	i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
+	ip_tunnel_flags_from_be16(p->i_flags, i_flags);
+	o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
+	ip_tunnel_flags_from_be16(p->o_flags, o_flags);
 
-	if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
-		return -EFAULT;
 	return 0;
 }
 
@@ -628,15 +928,18 @@ static int ipgre_open(struct net_device *dev)
 	struct ip_tunnel *t = netdev_priv(dev);
 
 	if (ipv4_is_multicast(t->parms.iph.daddr)) {
-		struct flowi4 fl4;
+		struct flowi4 fl4 = {
+			.flowi4_oif = t->parms.link,
+			.flowi4_dscp = ip4h_dscp(&t->parms.iph),
+			.flowi4_scope = RT_SCOPE_UNIVERSE,
+			.flowi4_proto = IPPROTO_GRE,
+			.saddr = t->parms.iph.saddr,
+			.daddr = t->parms.iph.daddr,
+			.fl4_gre_key = t->parms.o_key,
+		};
 		struct rtable *rt;
 
-		rt = ip_route_output_gre(t->net, &fl4,
-					 t->parms.iph.daddr,
-					 t->parms.iph.saddr,
-					 t->parms.o_key,
-					 RT_TOS(t->parms.iph.tos),
-					 t->parms.link);
+		rt = ip_route_output_key(t->net, &fl4);
 		if (IS_ERR(rt))
 			return -EADDRNOTAVAIL;
 		dev = rt->dst.dev;
@@ -671,10 +974,11 @@ static const struct net_device_ops ipgre_netdev_ops = {
 	.ndo_stop		= ipgre_close,
 #endif
 	.ndo_start_xmit		= ipgre_xmit,
-	.ndo_do_ioctl		= ipgre_tunnel_ioctl,
+	.ndo_siocdevprivate	= ip_tunnel_siocdevprivate,
 	.ndo_change_mtu		= ip_tunnel_change_mtu,
-	.ndo_get_stats64	= ip_tunnel_get_stats64,
+	.ndo_get_stats64	= dev_get_tstats64,
 	.ndo_get_iflink		= ip_tunnel_get_iflink,
+	.ndo_tunnel_ctl		= ipgre_tunnel_ctl,
 };
 
 #define GRE_FEATURES (NETIF_F_SG |		\
@@ -692,38 +996,30 @@ static void ipgre_tunnel_setup(struct net_device *dev)
 static void __gre_tunnel_init(struct net_device *dev)
 {
 	struct ip_tunnel *tunnel;
-	int t_hlen;
 
 	tunnel = netdev_priv(dev);
 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
 	tunnel->parms.iph.protocol = IPPROTO_GRE;
 
 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
-
-	t_hlen = tunnel->hlen + sizeof(struct iphdr);
-
-	dev->needed_headroom	= LL_MAX_HEADER + t_hlen + 4;
-	dev->mtu		= ETH_DATA_LEN - t_hlen - 4;
+	dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
 
 	dev->features		|= GRE_FEATURES;
 	dev->hw_features	|= GRE_FEATURES;
 
-	if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
-		/* TCP offload with GRE SEQ is not supported, nor
-		 * can we support 2 levels of outer headers requiring
-		 * an update.
-		 */
-		if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
-		    (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
-			dev->features    |= NETIF_F_GSO_SOFTWARE;
-			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
-		}
+	/* TCP offload with GRE SEQ is not supported, nor can we support 2
+	 * levels of outer headers requiring an update.
+	 */
+	if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags))
+		return;
+	if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&
+	    tunnel->encap.type != TUNNEL_ENCAP_NONE)
+		return;
 
-		/* Can use a lockless transmit, unless we generate
-		 * output sequences
-		 */
-		dev->features |= NETIF_F_LLTX;
-	}
+	dev->features |= NETIF_F_GSO_SOFTWARE;
+	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+
+	dev->lltx = true;
 }
 
 static int ipgre_tunnel_init(struct net_device *dev)
@@ -733,7 +1029,7 @@ static int ipgre_tunnel_init(struct net_device *dev)
 
 	__gre_tunnel_init(dev);
 
-	memcpy(dev->dev_addr, &iph->saddr, 4);
+	__dev_addr_set(dev, &iph->saddr, 4);
 	memcpy(dev->broadcast, &iph->daddr, 4);
 
 	dev->flags		= IFF_NOARP;
@@ -747,10 +1043,14 @@ static int ipgre_tunnel_init(struct net_device *dev)
 				return -EINVAL;
 			dev->flags = IFF_BROADCAST;
 			dev->header_ops = &ipgre_header_ops;
+			dev->hard_header_len = tunnel->hlen + sizeof(*iph);
+			dev->needed_headroom = 0;
 		}
 #endif
 	} else if (!tunnel->collect_md) {
 		dev->header_ops = &ipgre_header_ops;
+		dev->hard_header_len = tunnel->hlen + sizeof(*iph);
+		dev->needed_headroom = 0;
 	}
 
 	return ip_tunnel_init(dev);
@@ -766,15 +1066,15 @@ static int __net_init ipgre_init_net(struct net *net)
 	return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
 }
 
-static void __net_exit ipgre_exit_net(struct net *net)
+static void __net_exit ipgre_exit_rtnl(struct net *net,
+				       struct list_head *dev_to_kill)
 {
-	struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
-	ip_tunnel_delete_net(itn, &ipgre_link_ops);
+	ip_tunnel_delete_net(net, ipgre_net_id, &ipgre_link_ops, dev_to_kill);
 }
 
 static struct pernet_operations ipgre_net_ops = {
 	.init = ipgre_init_net,
-	.exit = ipgre_exit_net,
+	.exit_rtnl = ipgre_exit_rtnl,
 	.id   = &ipgre_net_id,
 	.size = sizeof(struct ip_tunnel_net),
 };
@@ -828,10 +1128,50 @@ out:
 	return ipgre_tunnel_validate(tb, data, extack);
 }
 
+static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
+			   struct netlink_ext_ack *extack)
+{
+	__be16 flags = 0;
+	int ret;
+
+	if (!data)
+		return 0;
+
+	ret = ipgre_tap_validate(tb, data, extack);
+	if (ret)
+		return ret;
+
+	if (data[IFLA_GRE_ERSPAN_VER] &&
+	    nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
+		return 0;
+
+	/* ERSPAN type II/III should only have GRE sequence and key flag */
+	if (data[IFLA_GRE_OFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+	if (data[IFLA_GRE_IFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+	if (!data[IFLA_GRE_COLLECT_METADATA] &&
+	    flags != (GRE_SEQ | GRE_KEY))
+		return -EINVAL;
+
+	/* ERSPAN Session ID only has 10-bit. Since we reuse
+	 * 32-bit key field as ID, check it's range.
+	 */
+	if (data[IFLA_GRE_IKEY] &&
+	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
+		return -EINVAL;
+
+	if (data[IFLA_GRE_OKEY] &&
+	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int ipgre_netlink_parms(struct net_device *dev,
 				struct nlattr *data[],
 				struct nlattr *tb[],
-				struct ip_tunnel_parm *parms,
+				struct ip_tunnel_parm_kern *parms,
 				__u32 *fwmark)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
@@ -847,10 +1187,12 @@ static int ipgre_netlink_parms(struct net_device *dev,
 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
 
 	if (data[IFLA_GRE_IFLAGS])
-		parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
+		gre_flags_to_tnl_flags(parms->i_flags,
+				       nla_get_be16(data[IFLA_GRE_IFLAGS]));
 
 	if (data[IFLA_GRE_OFLAGS])
-		parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
+		gre_flags_to_tnl_flags(parms->o_flags,
+				       nla_get_be16(data[IFLA_GRE_OFLAGS]));
 
 	if (data[IFLA_GRE_IKEY])
 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
@@ -895,6 +1237,50 @@ static int ipgre_netlink_parms(struct net_device *dev,
 	return 0;
 }
 
+static int erspan_netlink_parms(struct net_device *dev,
+				struct nlattr *data[],
+				struct nlattr *tb[],
+				struct ip_tunnel_parm_kern *parms,
+				__u32 *fwmark)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+	int err;
+
+	err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
+	if (err)
+		return err;
+	if (!data)
+		return 0;
+
+	if (data[IFLA_GRE_ERSPAN_VER]) {
+		t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
+
+		if (t->erspan_ver > 2)
+			return -EINVAL;
+	}
+
+	if (t->erspan_ver == 1) {
+		if (data[IFLA_GRE_ERSPAN_INDEX]) {
+			t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
+			if (t->index & ~INDEX_MASK)
+				return -EINVAL;
+		}
+	} else if (t->erspan_ver == 2) {
+		if (data[IFLA_GRE_ERSPAN_DIR]) {
+			t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
+			if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
+				return -EINVAL;
+		}
+		if (data[IFLA_GRE_ERSPAN_HWID]) {
+			t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
+			if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 /* This function returns true when ENCAP attributes are present in the nl msg */
 static bool ipgre_netlink_encap_parms(struct nlattr *data[],
 				      struct ip_tunnel_encap *ipencap)
@@ -933,6 +1319,7 @@ static int gre_tap_init(struct net_device *dev)
 {
 	__gre_tunnel_init(dev);
 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	netif_keep_dst(dev);
 
 	return ip_tunnel_init(dev);
 }
@@ -944,7 +1331,40 @@ static const struct net_device_ops gre_tap_netdev_ops = {
 	.ndo_set_mac_address 	= eth_mac_addr,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_change_mtu		= ip_tunnel_change_mtu,
-	.ndo_get_stats64	= ip_tunnel_get_stats64,
+	.ndo_get_stats64	= dev_get_tstats64,
+	.ndo_get_iflink		= ip_tunnel_get_iflink,
+	.ndo_fill_metadata_dst	= gre_fill_metadata_dst,
+};
+
+static int erspan_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+
+	if (tunnel->erspan_ver == 0)
+		tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
+	else
+		tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
+
+	tunnel->parms.iph.protocol = IPPROTO_GRE;
+	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
+		       erspan_hdr_len(tunnel->erspan_ver);
+
+	dev->features		|= GRE_FEATURES;
+	dev->hw_features	|= GRE_FEATURES;
+	dev->priv_flags		|= IFF_LIVE_ADDR_CHANGE;
+	netif_keep_dst(dev);
+
+	return ip_tunnel_init(dev);
+}
+
+static const struct net_device_ops erspan_netdev_ops = {
+	.ndo_init		= erspan_tunnel_init,
+	.ndo_uninit		= ip_tunnel_uninit,
+	.ndo_start_xmit		= erspan_xmit,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_change_mtu		= ip_tunnel_change_mtu,
+	.ndo_get_stats64	= dev_get_tstats64,
 	.ndo_get_iflink		= ip_tunnel_get_iflink,
 	.ndo_fill_metadata_dst	= gre_fill_metadata_dst,
 };
@@ -952,33 +1372,69 @@ static const struct net_device_ops gre_tap_netdev_ops = {
 static void ipgre_tap_setup(struct net_device *dev)
 {
 	ether_setup(dev);
+	dev->max_mtu = 0;
 	dev->netdev_ops	= &gre_tap_netdev_ops;
 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 	dev->priv_flags	|= IFF_LIVE_ADDR_CHANGE;
 	ip_tunnel_setup(dev, gre_tap_net_id);
 }
 
-static int ipgre_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
-			 struct netlink_ext_ack *extack)
+static int
+ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
 {
-	struct ip_tunnel_parm p;
 	struct ip_tunnel_encap ipencap;
-	__u32 fwmark = 0;
-	int err;
 
 	if (ipgre_netlink_encap_parms(data, &ipencap)) {
 		struct ip_tunnel *t = netdev_priv(dev);
-		err = ip_tunnel_encap_setup(t, &ipencap);
+		int err = ip_tunnel_encap_setup(t, &ipencap);
 
 		if (err < 0)
 			return err;
 	}
 
+	return 0;
+}
+
+static int ipgre_newlink(struct net_device *dev,
+			 struct rtnl_newlink_params *params,
+			 struct netlink_ext_ack *extack)
+{
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
+	struct ip_tunnel_parm_kern p;
+	__u32 fwmark = 0;
+	int err;
+
+	err = ipgre_newlink_encap_setup(dev, data);
+	if (err)
+		return err;
+
 	err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
 	if (err < 0)
 		return err;
-	return ip_tunnel_newlink(dev, tb, &p, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
+}
+
+static int erspan_newlink(struct net_device *dev,
+			  struct rtnl_newlink_params *params,
+			  struct netlink_ext_ack *extack)
+{
+	struct nlattr **data = params->data;
+	struct nlattr **tb = params->tb;
+	struct ip_tunnel_parm_kern p;
+	__u32 fwmark = 0;
+	int err;
+
+	err = ipgre_newlink_encap_setup(dev, data);
+	if (err)
+		return err;
+
+	err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
+	if (err)
+		return err;
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
 }
 
 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
@@ -986,22 +1442,55 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
 			    struct netlink_ext_ack *extack)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
-	struct ip_tunnel_parm p;
-	struct ip_tunnel_encap ipencap;
+	struct ip_tunnel_parm_kern p;
 	__u32 fwmark = t->fwmark;
 	int err;
 
-	if (ipgre_netlink_encap_parms(data, &ipencap)) {
-		err = ip_tunnel_encap_setup(t, &ipencap);
-
-		if (err < 0)
-			return err;
-	}
+	err = ipgre_newlink_encap_setup(dev, data);
+	if (err)
+		return err;
 
 	err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
 	if (err < 0)
 		return err;
-	return ip_tunnel_changelink(dev, tb, &p, fwmark);
+
+	err = ip_tunnel_changelink(dev, tb, &p, fwmark);
+	if (err < 0)
+		return err;
+
+	ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags);
+	ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags);
+
+	ipgre_link_update(dev, !tb[IFLA_MTU]);
+
+	return 0;
+}
+
+static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
+			     struct nlattr *data[],
+			     struct netlink_ext_ack *extack)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+	struct ip_tunnel_parm_kern p;
+	__u32 fwmark = t->fwmark;
+	int err;
+
+	err = ipgre_newlink_encap_setup(dev, data);
+	if (err)
+		return err;
+
+	err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
+	if (err < 0)
+		return err;
+
+	err = ip_tunnel_changelink(dev, tb, &p, fwmark);
+	if (err < 0)
+		return err;
+
+	ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags);
+	ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags);
+
+	return 0;
 }
 
 static size_t ipgre_get_size(const struct net_device *dev)
@@ -1041,19 +1530,30 @@ static size_t ipgre_get_size(const struct net_device *dev)
 		nla_total_size(1) +
 		/* IFLA_GRE_FWMARK */
 		nla_total_size(4) +
+		/* IFLA_GRE_ERSPAN_INDEX */
+		nla_total_size(4) +
+		/* IFLA_GRE_ERSPAN_VER */
+		nla_total_size(1) +
+		/* IFLA_GRE_ERSPAN_DIR */
+		nla_total_size(1) +
+		/* IFLA_GRE_ERSPAN_HWID */
+		nla_total_size(2) +
 		0;
 }
 
 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
-	struct ip_tunnel_parm *p = &t->parms;
+	struct ip_tunnel_parm_kern *p = &t->parms;
+	IP_TUNNEL_DECLARE_FLAGS(o_flags);
+
+	ip_tunnel_flags_copy(o_flags, p->o_flags);
 
 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
-			 gre_tnl_flags_to_gre_flags(p->o_flags)) ||
+			 gre_tnl_flags_to_gre_flags(o_flags)) ||
 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
 	    nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
@@ -1089,14 +1589,55 @@ nla_put_failure:
 	return -EMSGSIZE;
 }
 
+static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+
+	if (t->erspan_ver <= 2) {
+		if (t->erspan_ver != 0 && !t->collect_md)
+			__set_bit(IP_TUNNEL_KEY_BIT, t->parms.o_flags);
+
+		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
+			goto nla_put_failure;
+
+		if (t->erspan_ver == 1) {
+			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
+				goto nla_put_failure;
+		} else if (t->erspan_ver == 2) {
+			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
+				goto nla_put_failure;
+			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
+				goto nla_put_failure;
+		}
+	}
+
+	return ipgre_fill_info(skb, dev);
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static void erspan_setup(struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+
+	ether_setup(dev);
+	dev->max_mtu = 0;
+	dev->netdev_ops = &erspan_netdev_ops;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	ip_tunnel_setup(dev, erspan_net_id);
+	t->erspan_ver = 1;
+}
+
 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
 	[IFLA_GRE_LINK]		= { .type = NLA_U32 },
 	[IFLA_GRE_IFLAGS]	= { .type = NLA_U16 },
 	[IFLA_GRE_OFLAGS]	= { .type = NLA_U16 },
 	[IFLA_GRE_IKEY]		= { .type = NLA_U32 },
 	[IFLA_GRE_OKEY]		= { .type = NLA_U32 },
-	[IFLA_GRE_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
-	[IFLA_GRE_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
+	[IFLA_GRE_LOCAL]	= { .len = sizeof_field(struct iphdr, saddr) },
+	[IFLA_GRE_REMOTE]	= { .len = sizeof_field(struct iphdr, daddr) },
 	[IFLA_GRE_TTL]		= { .type = NLA_U8 },
 	[IFLA_GRE_TOS]		= { .type = NLA_U8 },
 	[IFLA_GRE_PMTUDISC]	= { .type = NLA_U8 },
@@ -1107,6 +1648,10 @@ static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
 	[IFLA_GRE_COLLECT_METADATA]	= { .type = NLA_FLAG },
 	[IFLA_GRE_IGNORE_DF]	= { .type = NLA_U8 },
 	[IFLA_GRE_FWMARK]	= { .type = NLA_U32 },
+	[IFLA_GRE_ERSPAN_INDEX]	= { .type = NLA_U32 },
+	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
+	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
+	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
 };
 
 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
@@ -1139,9 +1684,25 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
 	.get_link_net	= ip_tunnel_get_link_net,
 };
 
+static struct rtnl_link_ops erspan_link_ops __read_mostly = {
+	.kind		= "erspan",
+	.maxtype	= IFLA_GRE_MAX,
+	.policy		= ipgre_policy,
+	.priv_size	= sizeof(struct ip_tunnel),
+	.setup		= erspan_setup,
+	.validate	= erspan_validate,
+	.newlink	= erspan_newlink,
+	.changelink	= erspan_changelink,
+	.dellink	= ip_tunnel_dellink,
+	.get_size	= ipgre_get_size,
+	.fill_info	= erspan_fill_info,
+	.get_link_net	= ip_tunnel_get_link_net,
+};
+
 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 					u8 name_assign_type)
 {
+	struct rtnl_newlink_params params = { .src_net = net };
 	struct nlattr *tb[IFLA_MAX + 1];
 	struct net_device *dev;
 	LIST_HEAD(list_kill);
@@ -1149,9 +1710,10 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	int err;
 
 	memset(&tb, 0, sizeof(tb));
+	params.tb = tb;
 
 	dev = rtnl_create_link(net, name, name_assign_type,
-			       &ipgre_tap_ops, tb);
+			       &ipgre_tap_ops, tb, NULL);
 	if (IS_ERR(dev))
 		return dev;
 
@@ -1159,7 +1721,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	t = netdev_priv(dev);
 	t->collect_md = true;
 
-	err = ipgre_newlink(net, dev, tb, NULL, NULL);
+	err = ipgre_newlink(dev, &params, NULL);
 	if (err < 0) {
 		free_netdev(dev);
 		return ERR_PTR(err);
@@ -1172,7 +1734,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	if (err)
 		goto out;
 
-	err = rtnl_configure_link(dev, NULL);
+	err = rtnl_configure_link(dev, NULL, 0, NULL);
 	if (err < 0)
 		goto out;
 
@@ -1189,19 +1751,38 @@ static int __net_init ipgre_tap_init_net(struct net *net)
 	return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
 }
 
-static void __net_exit ipgre_tap_exit_net(struct net *net)
+static void __net_exit ipgre_tap_exit_rtnl(struct net *net,
+					   struct list_head *dev_to_kill)
 {
-	struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id);
-	ip_tunnel_delete_net(itn, &ipgre_tap_ops);
+	ip_tunnel_delete_net(net, gre_tap_net_id, &ipgre_tap_ops, dev_to_kill);
 }
 
 static struct pernet_operations ipgre_tap_net_ops = {
 	.init = ipgre_tap_init_net,
-	.exit = ipgre_tap_exit_net,
+	.exit_rtnl = ipgre_tap_exit_rtnl,
 	.id   = &gre_tap_net_id,
 	.size = sizeof(struct ip_tunnel_net),
 };
 
+static int __net_init erspan_init_net(struct net *net)
+{
+	return ip_tunnel_init_net(net, erspan_net_id,
+				  &erspan_link_ops, "erspan0");
+}
+
+static void __net_exit erspan_exit_rtnl(struct net *net,
+					struct list_head *dev_to_kill)
+{
+	ip_tunnel_delete_net(net, erspan_net_id, &erspan_link_ops, dev_to_kill);
+}
+
+static struct pernet_operations erspan_net_ops = {
+	.init = erspan_init_net,
+	.exit_rtnl = erspan_exit_rtnl,
+	.id   = &erspan_net_id,
+	.size = sizeof(struct ip_tunnel_net),
+};
+
 static int __init ipgre_init(void)
 {
 	int err;
@@ -1214,7 +1795,11 @@ static int __init ipgre_init(void)
 
 	err = register_pernet_device(&ipgre_tap_net_ops);
 	if (err < 0)
-		goto pnet_tap_faied;
+		goto pnet_tap_failed;
+
+	err = register_pernet_device(&erspan_net_ops);
+	if (err < 0)
+		goto pnet_erspan_failed;
 
 	err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
 	if (err < 0) {
@@ -1230,15 +1815,23 @@ static int __init ipgre_init(void)
 	if (err < 0)
 		goto tap_ops_failed;
 
+	err = rtnl_link_register(&erspan_link_ops);
+	if (err < 0)
+		goto erspan_link_failed;
+
 	return 0;
 
+erspan_link_failed:
+	rtnl_link_unregister(&ipgre_tap_ops);
 tap_ops_failed:
 	rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
 	gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 add_proto_failed:
+	unregister_pernet_device(&erspan_net_ops);
+pnet_erspan_failed:
 	unregister_pernet_device(&ipgre_tap_net_ops);
-pnet_tap_faied:
+pnet_tap_failed:
 	unregister_pernet_device(&ipgre_net_ops);
 	return err;
 }
@@ -1247,15 +1840,20 @@ static void __exit ipgre_fini(void)
 {
 	rtnl_link_unregister(&ipgre_tap_ops);
 	rtnl_link_unregister(&ipgre_link_ops);
+	rtnl_link_unregister(&erspan_link_ops);
 	gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 	unregister_pernet_device(&ipgre_tap_net_ops);
 	unregister_pernet_device(&ipgre_net_ops);
+	unregister_pernet_device(&erspan_net_ops);
 }
 
 module_init(ipgre_init);
 module_exit(ipgre_fini);
+MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("gre");
 MODULE_ALIAS_RTNL_LINK("gretap");
+MODULE_ALIAS_RTNL_LINK("erspan");
 MODULE_ALIAS_NETDEV("gre0");
 MODULE_ALIAS_NETDEV("gretap0");
+MODULE_ALIAS_NETDEV("erspan0");