openvswitch: Add conntrack action

Expose the kernel connection tracker via OVS. Userspace components can
make use of the CT action to populate the connection state (ct_state)
field for a flow. This state can be subsequently matched.

Exposed connection states are OVS_CS_F_*:
- NEW (0x01) - Beginning of a new connection.
- ESTABLISHED (0x02) - Part of an existing connection.
- RELATED (0x04) - Related to an established connection.
- INVALID (0x20) - Could not track the connection for this packet.
- REPLY_DIR (0x40) - This packet is in the reply direction for the flow.
- TRACKED (0x80) - This packet has been sent through conntrack.

When the CT action is executed by itself, it will send the packet
through the connection tracker and populate the ct_state field with one
or more of the connection state flags above. The CT action will always
set the TRACKED bit.

When the COMMIT flag is passed to the conntrack action, this specifies
that information about the connection should be stored. This allows
subsequent packets for the same (or related) connections to be
correlated with this connection. Sending subsequent packets for the
connection through conntrack allows the connection tracker to consider
the packets as ESTABLISHED, RELATED, and/or REPLY_DIR.

The CT action may optionally take a zone to track the flow within. This
allows connections with the same 5-tuple to be kept logically separate
from connections in other zones. If the zone is specified, then the
"ct_zone" match field will be subsequently populated with the zone id.

IP fragments are handled by transparently assembling them as part of the
CT action. The maximum received unit (MRU) size is tracked so that
refragmentation can occur during output.

IP frag handling contributed by Andy Zhou.

Based on original design by Justin Pettit.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Signed-off-by: Justin Pettit <jpettit@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

12 files changed, 837 insertions, 37 deletions

diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig
index 422dc0567de9..98f343d0d6dd 100644
--- a/net/openvswitch/Kconfig
+++ b/net/openvswitch/Kconfig
@@ -31,6 +31,17 @@ config OPENVSWITCH
 
 	  If unsure, say N.
 
+config OPENVSWITCH_CONNTRACK
+	bool "Open vSwitch conntrack action support"
+	depends on OPENVSWITCH
+	depends on NF_CONNTRACK
+	default OPENVSWITCH
+	---help---
+	  If you say Y here, then Open vSwitch module will be able to pass
+	  packets through conntrack.
+
+	  Say N to exclude this support and reduce the binary size.
+
 config OPENVSWITCH_GRE
 	tristate "Open vSwitch GRE tunneling support"
 	depends on OPENVSWITCH
diff --git a/net/openvswitch/Makefile b/net/openvswitch/Makefile
index 6e1701de04d8..5b5913b06f54 100644
--- a/net/openvswitch/Makefile
+++ b/net/openvswitch/Makefile
@@ -15,6 +15,8 @@ openvswitch-y := \
 	vport-internal_dev.o \
 	vport-netdev.o
 
+openvswitch-$(CONFIG_OPENVSWITCH_CONNTRACK) += conntrack.o
+
 obj-$(CONFIG_OPENVSWITCH_VXLAN)+= vport-vxlan.o
 obj-$(CONFIG_OPENVSWITCH_GENEVE)+= vport-geneve.o
 obj-$(CONFIG_OPENVSWITCH_GRE)	+= vport-gre.o
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 520438b77dc8..72ca2c491b0a 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -22,6 +22,7 @@
 #include <linux/in.h>
 #include <linux/ip.h>
 #include <linux/openvswitch.h>
+#include <linux/netfilter_ipv6.h>
 #include <linux/sctp.h>
 #include <linux/tcp.h>
 #include <linux/udp.h>
@@ -29,6 +30,7 @@
 #include <linux/if_arp.h>
 #include <linux/if_vlan.h>
 
+#include <net/dst.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/checksum.h>
@@ -38,6 +40,7 @@
 
 #include "datapath.h"
 #include "flow.h"
+#include "conntrack.h"
 #include "vport.h"
 
 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
@@ -52,6 +55,20 @@ struct deferred_action {
 	struct sw_flow_key pkt_key;
 };
 
+#define MAX_L2_LEN	(VLAN_ETH_HLEN + 3 * MPLS_HLEN)
+struct ovs_frag_data {
+	unsigned long dst;
+	struct vport *vport;
+	struct ovs_skb_cb cb;
+	__be16 inner_protocol;
+	__u16 vlan_tci;
+	__be16 vlan_proto;
+	unsigned int l2_len;
+	u8 l2_data[MAX_L2_LEN];
+};
+
+static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
+
 #define DEFERRED_ACTION_FIFO_SIZE 10
 struct action_fifo {
 	int head;
@@ -602,14 +619,145 @@ static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 	return 0;
 }
 
-static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
+static int ovs_vport_output(struct sock *sock, struct sk_buff *skb)
+{
+	struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
+	struct vport *vport = data->vport;
+
+	if (skb_cow_head(skb, data->l2_len) < 0) {
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	__skb_dst_copy(skb, data->dst);
+	*OVS_CB(skb) = data->cb;
+	skb->inner_protocol = data->inner_protocol;
+	skb->vlan_tci = data->vlan_tci;
+	skb->vlan_proto = data->vlan_proto;
+
+	/* Reconstruct the MAC header.  */
+	skb_push(skb, data->l2_len);
+	memcpy(skb->data, &data->l2_data, data->l2_len);
+	ovs_skb_postpush_rcsum(skb, skb->data, data->l2_len);
+	skb_reset_mac_header(skb);
+
+	ovs_vport_send(vport, skb);
+	return 0;
+}
+
+static unsigned int
+ovs_dst_get_mtu(const struct dst_entry *dst)
+{
+	return dst->dev->mtu;
+}
+
+static struct dst_ops ovs_dst_ops = {
+	.family = AF_UNSPEC,
+	.mtu = ovs_dst_get_mtu,
+};
+
+/* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
+ * ovs_vport_output(), which is called once per fragmented packet.
+ */
+static void prepare_frag(struct vport *vport, struct sk_buff *skb)
+{
+	unsigned int hlen = skb_network_offset(skb);
+	struct ovs_frag_data *data;
+
+	data = this_cpu_ptr(&ovs_frag_data_storage);
+	data->dst = skb->_skb_refdst;
+	data->vport = vport;
+	data->cb = *OVS_CB(skb);
+	data->inner_protocol = skb->inner_protocol;
+	data->vlan_tci = skb->vlan_tci;
+	data->vlan_proto = skb->vlan_proto;
+	data->l2_len = hlen;
+	memcpy(&data->l2_data, skb->data, hlen);
+
+	memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+	skb_pull(skb, hlen);
+}
+
+static void ovs_fragment(struct vport *vport, struct sk_buff *skb, u16 mru,
+			 __be16 ethertype)
+{
+	if (skb_network_offset(skb) > MAX_L2_LEN) {
+		OVS_NLERR(1, "L2 header too long to fragment");
+		return;
+	}
+
+	if (ethertype == htons(ETH_P_IP)) {
+		struct dst_entry ovs_dst;
+		unsigned long orig_dst;
+
+		prepare_frag(vport, skb);
+		dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
+			 DST_OBSOLETE_NONE, DST_NOCOUNT);
+		ovs_dst.dev = vport->dev;
+
+		orig_dst = skb->_skb_refdst;
+		skb_dst_set_noref(skb, &ovs_dst);
+		IPCB(skb)->frag_max_size = mru;
+
+		ip_do_fragment(skb->sk, skb, ovs_vport_output);
+		refdst_drop(orig_dst);
+	} else if (ethertype == htons(ETH_P_IPV6)) {
+		const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
+		unsigned long orig_dst;
+		struct rt6_info ovs_rt;
+
+		if (!v6ops) {
+			kfree_skb(skb);
+			return;
+		}
+
+		prepare_frag(vport, skb);
+		memset(&ovs_rt, 0, sizeof(ovs_rt));
+		dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
+			 DST_OBSOLETE_NONE, DST_NOCOUNT);
+		ovs_rt.dst.dev = vport->dev;
+
+		orig_dst = skb->_skb_refdst;
+		skb_dst_set_noref(skb, &ovs_rt.dst);
+		IP6CB(skb)->frag_max_size = mru;
+
+		v6ops->fragment(skb->sk, skb, ovs_vport_output);
+		refdst_drop(orig_dst);
+	} else {
+		WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
+			  ovs_vport_name(vport), ntohs(ethertype), mru,
+			  vport->dev->mtu);
+		kfree_skb(skb);
+	}
+}
+
+static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
+		      struct sw_flow_key *key)
 {
 	struct vport *vport = ovs_vport_rcu(dp, out_port);
 
-	if (likely(vport))
-		ovs_vport_send(vport, skb);
-	else
+	if (likely(vport)) {
+		u16 mru = OVS_CB(skb)->mru;
+
+		if (likely(!mru || (skb->len <= mru + ETH_HLEN))) {
+			ovs_vport_send(vport, skb);
+		} else if (mru <= vport->dev->mtu) {
+			__be16 ethertype = key->eth.type;
+
+			if (!is_flow_key_valid(key)) {
+				if (eth_p_mpls(skb->protocol))
+					ethertype = skb->inner_protocol;
+				else
+					ethertype = vlan_get_protocol(skb);
+			}
+
+			ovs_fragment(vport, skb, mru, ethertype);
+		} else {
+			kfree_skb(skb);
+		}
+	} else {
 		kfree_skb(skb);
+	}
 }
 
 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
@@ -623,6 +771,7 @@ static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 
 	memset(&upcall, 0, sizeof(upcall));
 	upcall.cmd = OVS_PACKET_CMD_ACTION;
+	upcall.mru = OVS_CB(skb)->mru;
 
 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 		 a = nla_next(a, &rem)) {
@@ -816,6 +965,11 @@ static int execute_masked_set_action(struct sk_buff *skb,
 		err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
 								    __be32 *));
 		break;
+
+	case OVS_KEY_ATTR_CT_STATE:
+	case OVS_KEY_ATTR_CT_ZONE:
+		err = -EINVAL;
+		break;
 	}
 
 	return err;
@@ -885,7 +1039,7 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
 
 			if (out_skb)
-				do_output(dp, out_skb, prev_port);
+				do_output(dp, out_skb, prev_port, key);
 
 			prev_port = -1;
 		}
@@ -942,6 +1096,15 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 		case OVS_ACTION_ATTR_SAMPLE:
 			err = sample(dp, skb, key, a, attr, len);
 			break;
+
+		case OVS_ACTION_ATTR_CT:
+			err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
+					     nla_data(a));
+
+			/* Hide stolen IP fragments from user space. */
+			if (err == -EINPROGRESS)
+				return 0;
+			break;
 		}
 
 		if (unlikely(err)) {
@@ -951,7 +1114,7 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 	}
 
 	if (prev_port != -1)
-		do_output(dp, skb, prev_port);
+		do_output(dp, skb, prev_port, key);
 	else
 		consume_skb(skb);
 
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
new file mode 100644
index 000000000000..1189fd50f1cf
--- /dev/null
+++ b/net/openvswitch/conntrack.c
@@ -0,0 +1,454 @@
+/*
+ * Copyright (c) 2015 Nicira, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/openvswitch.h>
+#include <net/ip.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
+
+#include "datapath.h"
+#include "conntrack.h"
+#include "flow.h"
+#include "flow_netlink.h"
+
+struct ovs_ct_len_tbl {
+	size_t maxlen;
+	size_t minlen;
+};
+
+/* Conntrack action context for execution. */
+struct ovs_conntrack_info {
+	struct nf_conntrack_zone zone;
+	struct nf_conn *ct;
+	u32 flags;
+	u16 family;
+};
+
+static u16 key_to_nfproto(const struct sw_flow_key *key)
+{
+	switch (ntohs(key->eth.type)) {
+	case ETH_P_IP:
+		return NFPROTO_IPV4;
+	case ETH_P_IPV6:
+		return NFPROTO_IPV6;
+	default:
+		return NFPROTO_UNSPEC;
+	}
+}
+
+/* Map SKB connection state into the values used by flow definition. */
+static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
+{
+	u8 ct_state = OVS_CS_F_TRACKED;
+
+	switch (ctinfo) {
+	case IP_CT_ESTABLISHED_REPLY:
+	case IP_CT_RELATED_REPLY:
+	case IP_CT_NEW_REPLY:
+		ct_state |= OVS_CS_F_REPLY_DIR;
+		break;
+	default:
+		break;
+	}
+
+	switch (ctinfo) {
+	case IP_CT_ESTABLISHED:
+	case IP_CT_ESTABLISHED_REPLY:
+		ct_state |= OVS_CS_F_ESTABLISHED;
+		break;
+	case IP_CT_RELATED:
+	case IP_CT_RELATED_REPLY:
+		ct_state |= OVS_CS_F_RELATED;
+		break;
+	case IP_CT_NEW:
+	case IP_CT_NEW_REPLY:
+		ct_state |= OVS_CS_F_NEW;
+		break;
+	default:
+		break;
+	}
+
+	return ct_state;
+}
+
+static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
+				const struct nf_conntrack_zone *zone)
+{
+	key->ct.state = state;
+	key->ct.zone = zone->id;
+}
+
+/* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
+ * previously sent the packet to conntrack via the ct action.
+ */
+static void ovs_ct_update_key(const struct sk_buff *skb,
+			      struct sw_flow_key *key, bool post_ct)
+{
+	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	u8 state = 0;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct) {
+		state = ovs_ct_get_state(ctinfo);
+		if (ct->master)
+			state |= OVS_CS_F_RELATED;
+		zone = nf_ct_zone(ct);
+	} else if (post_ct) {
+		state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
+	}
+	__ovs_ct_update_key(key, state, zone);
+}
+
+void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
+{
+	ovs_ct_update_key(skb, key, false);
+}
+
+int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
+{
+	if (nla_put_u8(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
+		return -EMSGSIZE;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
+	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int handle_fragments(struct net *net, struct sw_flow_key *key,
+			    u16 zone, struct sk_buff *skb)
+{
+	struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
+
+	if (key->eth.type == htons(ETH_P_IP)) {
+		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
+		int err;
+
+		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+		err = ip_defrag(skb, user);
+		if (err)
+			return err;
+
+		ovs_cb.mru = IPCB(skb)->frag_max_size;
+	} else if (key->eth.type == htons(ETH_P_IPV6)) {
+#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
+		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
+		struct sk_buff *reasm;
+
+		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
+		reasm = nf_ct_frag6_gather(skb, user);
+		if (!reasm)
+			return -EINPROGRESS;
+
+		if (skb == reasm)
+			return -EINVAL;
+
+		key->ip.proto = ipv6_hdr(reasm)->nexthdr;
+		skb_morph(skb, reasm);
+		consume_skb(reasm);
+		ovs_cb.mru = IP6CB(skb)->frag_max_size;
+#else
+		return -EPFNOSUPPORT;
+#endif
+	} else {
+		return -EPFNOSUPPORT;
+	}
+
+	key->ip.frag = OVS_FRAG_TYPE_NONE;
+	skb_clear_hash(skb);
+	skb->ignore_df = 1;
+	*OVS_CB(skb) = ovs_cb;
+
+	return 0;
+}
+
+static struct nf_conntrack_expect *
+ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
+		   u16 proto, const struct sk_buff *skb)
+{
+	struct nf_conntrack_tuple tuple;
+
+	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
+		return NULL;
+	return __nf_ct_expect_find(net, zone, &tuple);
+}
+
+/* Determine whether skb->nfct is equal to the result of conntrack lookup. */
+static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
+			    const struct ovs_conntrack_info *info)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		return false;
+	if (!net_eq(net, read_pnet(&ct->ct_net)))
+		return false;
+	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
+		return false;
+
+	return true;
+}
+
+static int __ovs_ct_lookup(struct net *net, const struct sw_flow_key *key,
+			   const struct ovs_conntrack_info *info,
+			   struct sk_buff *skb)
+{
+	/* If we are recirculating packets to match on conntrack fields and
+	 * committing with a separate conntrack action,  then we don't need to
+	 * actually run the packet through conntrack twice unless it's for a
+	 * different zone.
+	 */
+	if (!skb_nfct_cached(net, skb, info)) {
+		struct nf_conn *tmpl = info->ct;
+
+		/* Associate skb with specified zone. */
+		if (tmpl) {
+			if (skb->nfct)
+				nf_conntrack_put(skb->nfct);
+			nf_conntrack_get(&tmpl->ct_general);
+			skb->nfct = &tmpl->ct_general;
+			skb->nfctinfo = IP_CT_NEW;
+		}
+
+		if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
+				    skb) != NF_ACCEPT)
+			return -ENOENT;
+	}
+
+	return 0;
+}
+
+/* Lookup connection and read fields into key. */
+static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
+			 const struct ovs_conntrack_info *info,
+			 struct sk_buff *skb)
+{
+	struct nf_conntrack_expect *exp;
+
+	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
+	if (exp) {
+		u8 state;
+
+		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
+		__ovs_ct_update_key(key, state, &info->zone);
+	} else {
+		int err;
+
+		err = __ovs_ct_lookup(net, key, info, skb);
+		if (err)
+			return err;
+
+		ovs_ct_update_key(skb, key, true);
+	}
+
+	return 0;
+}
+
+/* Lookup connection and confirm if unconfirmed. */
+static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
+			 const struct ovs_conntrack_info *info,
+			 struct sk_buff *skb)
+{
+	u8 state;
+	int err;
+
+	state = key->ct.state;
+	if (key->ct.zone == info->zone.id &&
+	    ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
+		/* Previous lookup has shown that this connection is already
+		 * tracked and committed. Skip committing.
+		 */
+		return 0;
+	}
+
+	err = __ovs_ct_lookup(net, key, info, skb);
+	if (err)
+		return err;
+	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
+		return -EINVAL;
+
+	ovs_ct_update_key(skb, key, true);
+
+	return 0;
+}
+
+int ovs_ct_execute(struct net *net, struct sk_buff *skb,
+		   struct sw_flow_key *key,
+		   const struct ovs_conntrack_info *info)
+{
+	int nh_ofs;
+	int err;
+
+	/* The conntrack module expects to be working at L3. */
+	nh_ofs = skb_network_offset(skb);
+	skb_pull(skb, nh_ofs);
+
+	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
+		err = handle_fragments(net, key, info->zone.id, skb);
+		if (err)
+			return err;
+	}
+
+	if (info->flags & OVS_CT_F_COMMIT)
+		err = ovs_ct_commit(net, key, info, skb);
+	else
+		err = ovs_ct_lookup(net, key, info, skb);
+
+	skb_push(skb, nh_ofs);
+	return err;
+}
+
+static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
+	[OVS_CT_ATTR_FLAGS]	= { .minlen = sizeof(u32),
+				    .maxlen = sizeof(u32) },
+	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
+				    .maxlen = sizeof(u16) },
+};
+
+static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
+		    bool log)
+{
+	struct nlattr *a;
+	int rem;
+
+	nla_for_each_nested(a, attr, rem) {
+		int type = nla_type(a);
+		int maxlen = ovs_ct_attr_lens[type].maxlen;
+		int minlen = ovs_ct_attr_lens[type].minlen;
+
+		if (type > OVS_CT_ATTR_MAX) {
+			OVS_NLERR(log,
+				  "Unknown conntrack attr (type=%d, max=%d)",
+				  type, OVS_CT_ATTR_MAX);
+			return -EINVAL;
+		}
+		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
+			OVS_NLERR(log,
+				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
+				  type, nla_len(a), maxlen);
+			return -EINVAL;
+		}
+
+		switch (type) {
+		case OVS_CT_ATTR_FLAGS:
+			info->flags = nla_get_u32(a);
+			break;
+#ifdef CONFIG_NF_CONNTRACK_ZONES
+		case OVS_CT_ATTR_ZONE:
+			info->zone.id = nla_get_u16(a);
+			break;
+#endif
+		default:
+			OVS_NLERR(log, "Unknown conntrack attr (%d)",
+				  type);
+			return -EINVAL;
+		}
+	}
+
+	if (rem > 0) {
+		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+bool ovs_ct_verify(enum ovs_key_attr attr)
+{
+	if (attr == OVS_KEY_ATTR_CT_STATE)
+		return true;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
+	    attr == OVS_KEY_ATTR_CT_ZONE)
+		return true;
+
+	return false;
+}
+
+int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
+		       const struct sw_flow_key *key,
+		       struct sw_flow_actions **sfa,  bool log)
+{
+	struct ovs_conntrack_info ct_info;
+	u16 family;
+	int err;
+
+	family = key_to_nfproto(key);
+	if (family == NFPROTO_UNSPEC) {
+		OVS_NLERR(log, "ct family unspecified");
+		return -EINVAL;
+	}
+
+	memset(&ct_info, 0, sizeof(ct_info));
+	ct_info.family = family;
+
+	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
+			NF_CT_DEFAULT_ZONE_DIR, 0);
+
+	err = parse_ct(attr, &ct_info, log);
+	if (err)
+		return err;
+
+	/* Set up template for tracking connections in specific zones. */
+	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
+	if (!ct_info.ct) {
+		OVS_NLERR(log, "Failed to allocate conntrack template");
+		return -ENOMEM;
+	}
+
+	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
+				 sizeof(ct_info), log);
+	if (err)
+		goto err_free_ct;
+
+	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
+	nf_conntrack_get(&ct_info.ct->ct_general);
+	return 0;
+err_free_ct:
+	nf_conntrack_free(ct_info.ct);
+	return err;
+}
+
+int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
+			  struct sk_buff *skb)
+{
+	struct nlattr *start;
+
+	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
+	if (!start)
+		return -EMSGSIZE;
+
+	if (nla_put_u32(skb, OVS_CT_ATTR_FLAGS, ct_info->flags))
+		return -EMSGSIZE;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
+	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
+		return -EMSGSIZE;
+
+	nla_nest_end(skb, start);
+
+	return 0;
+}
+
+void ovs_ct_free_action(const struct nlattr *a)
+{
+	struct ovs_conntrack_info *ct_info = nla_data(a);
+
+	if (ct_info->ct)
+		nf_ct_put(ct_info->ct);
+}
diff --git a/net/openvswitch/conntrack.h b/net/openvswitch/conntrack.h
new file mode 100644
index 000000000000..e812ee64a718
--- /dev/null
+++ b/net/openvswitch/conntrack.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2015 Nicira, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef OVS_CONNTRACK_H
+#define OVS_CONNTRACK_H 1
+
+#include "flow.h"
+
+struct ovs_conntrack_info;
+enum ovs_key_attr;
+
+#if defined(CONFIG_OPENVSWITCH_CONNTRACK)
+bool ovs_ct_verify(enum ovs_key_attr attr);
+int ovs_ct_copy_action(struct net *, const struct nlattr *,
+		       const struct sw_flow_key *, struct sw_flow_actions **,
+		       bool log);
+int ovs_ct_action_to_attr(const struct ovs_conntrack_info *, struct sk_buff *);
+
+int ovs_ct_execute(struct net *, struct sk_buff *, struct sw_flow_key *,
+		   const struct ovs_conntrack_info *);
+
+void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key);
+int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb);
+void ovs_ct_free_action(const struct nlattr *a);
+#else
+#include <linux/errno.h>
+
+static inline bool ovs_ct_verify(int attr)
+{
+	return false;
+}
+
+static inline int ovs_ct_copy_action(struct net *net, const struct nlattr *nla,
+				     const struct sw_flow_key *key,
+				     struct sw_flow_actions **acts, bool log)
+{
+	return -ENOTSUPP;
+}
+
+static inline int ovs_ct_action_to_attr(const struct ovs_conntrack_info *info,
+					struct sk_buff *skb)
+{
+	return -ENOTSUPP;
+}
+
+static inline int ovs_ct_execute(struct net *net, struct sk_buff *skb,
+				 struct sw_flow_key *key,
+				 const struct ovs_conntrack_info *info)
+{
+	return -ENOTSUPP;
+}
+
+static inline void ovs_ct_fill_key(const struct sk_buff *skb,
+				   struct sw_flow_key *key)
+{
+	key->ct.state = 0;
+	key->ct.zone = 0;
+}
+
+static inline int ovs_ct_put_key(const struct sw_flow_key *key,
+				 struct sk_buff *skb)
+{
+	return 0;
+}
+
+static inline void ovs_ct_free_action(const struct nlattr *a) { }
+#endif
+#endif /* ovs_conntrack.h */
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index d5b547375887..72e63726efa0 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -275,6 +275,7 @@ void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key)
 		memset(&upcall, 0, sizeof(upcall));
 		upcall.cmd = OVS_PACKET_CMD_MISS;
 		upcall.portid = ovs_vport_find_upcall_portid(p, skb);
+		upcall.mru = OVS_CB(skb)->mru;
 		error = ovs_dp_upcall(dp, skb, key, &upcall);
 		if (unlikely(error))
 			kfree_skb(skb);
@@ -400,9 +401,23 @@ static size_t upcall_msg_size(const struct dp_upcall_info *upcall_info,
 	if (upcall_info->actions_len)
 		size += nla_total_size(upcall_info->actions_len);
 
+	/* OVS_PACKET_ATTR_MRU */
+	if (upcall_info->mru)
+		size += nla_total_size(sizeof(upcall_info->mru));
+
 	return size;
 }
 
+static void pad_packet(struct datapath *dp, struct sk_buff *skb)
+{
+	if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
+		size_t plen = NLA_ALIGN(skb->len) - skb->len;
+
+		if (plen > 0)
+			memset(skb_put(skb, plen), 0, plen);
+	}
+}
+
 static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 				  const struct sw_flow_key *key,
 				  const struct dp_upcall_info *upcall_info)
@@ -492,6 +507,16 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 			nla_nest_cancel(user_skb, nla);
 	}
 
+	/* Add OVS_PACKET_ATTR_MRU */
+	if (upcall_info->mru) {
+		if (nla_put_u16(user_skb, OVS_PACKET_ATTR_MRU,
+				upcall_info->mru)) {
+			err = -ENOBUFS;
+			goto out;
+		}
+		pad_packet(dp, user_skb);
+	}
+
 	/* Only reserve room for attribute header, packet data is added
 	 * in skb_zerocopy() */
 	if (!(nla = nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, 0))) {
@@ -505,12 +530,7 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 		goto out;
 
 	/* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
-	if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
-		size_t plen = NLA_ALIGN(user_skb->len) - user_skb->len;
-
-		if (plen > 0)
-			memset(skb_put(user_skb, plen), 0, plen);
-	}
+	pad_packet(dp, user_skb);
 
 	((struct nlmsghdr *) user_skb->data)->nlmsg_len = user_skb->len;
 
@@ -527,6 +547,7 @@ out:
 static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 {
 	struct ovs_header *ovs_header = info->userhdr;
+	struct net *net = sock_net(skb->sk);
 	struct nlattr **a = info->attrs;
 	struct sw_flow_actions *acts;
 	struct sk_buff *packet;
@@ -535,6 +556,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 	struct datapath *dp;
 	struct ethhdr *eth;
 	struct vport *input_vport;
+	u16 mru = 0;
 	int len;
 	int err;
 	bool log = !a[OVS_PACKET_ATTR_PROBE];
@@ -564,6 +586,13 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 	else
 		packet->protocol = htons(ETH_P_802_2);
 
+	/* Set packet's mru */
+	if (a[OVS_PACKET_ATTR_MRU]) {
+		mru = nla_get_u16(a[OVS_PACKET_ATTR_MRU]);
+		packet->ignore_df = 1;
+	}
+	OVS_CB(packet)->mru = mru;
+
 	/* Build an sw_flow for sending this packet. */
 	flow = ovs_flow_alloc();
 	err = PTR_ERR(flow);
@@ -575,7 +604,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 	if (err)
 		goto err_flow_free;
 
-	err = ovs_nla_copy_actions(a[OVS_PACKET_ATTR_ACTIONS],
+	err = ovs_nla_copy_actions(net, a[OVS_PACKET_ATTR_ACTIONS],
 				   &flow->key, &acts, log);
 	if (err)
 		goto err_flow_free;
@@ -586,7 +615,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 	packet->mark = flow->key.phy.skb_mark;
 
 	rcu_read_lock();
-	dp = get_dp_rcu(sock_net(skb->sk), ovs_header->dp_ifindex);
+	dp = get_dp_rcu(net, ovs_header->dp_ifindex);
 	err = -ENODEV;
 	if (!dp)
 		goto err_unlock;
@@ -598,6 +627,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 	if (!input_vport)
 		goto err_unlock;
 
+	packet->dev = input_vport->dev;
 	OVS_CB(packet)->input_vport = input_vport;
 	sf_acts = rcu_dereference(flow->sf_acts);
 
@@ -624,6 +654,7 @@ static const struct nla_policy packet_policy[OVS_PACKET_ATTR_MAX + 1] = {
 	[OVS_PACKET_ATTR_KEY] = { .type = NLA_NESTED },
 	[OVS_PACKET_ATTR_ACTIONS] = { .type = NLA_NESTED },
 	[OVS_PACKET_ATTR_PROBE] = { .type = NLA_FLAG },
+	[OVS_PACKET_ATTR_MRU] = { .type = NLA_U16 },
 };
 
 static const struct genl_ops dp_packet_genl_ops[] = {
@@ -880,6 +911,7 @@ static struct sk_buff *ovs_flow_cmd_build_info(const struct sw_flow *flow,
 
 static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
+	struct net *net = sock_net(skb->sk);
 	struct nlattr **a = info->attrs;
 	struct ovs_header *ovs_header = info->userhdr;
 	struct sw_flow *flow = NULL, *new_flow;
@@ -929,8 +961,8 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 		goto err_kfree_flow;
 
 	/* Validate actions. */
-	error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS], &new_flow->key,
-				     &acts, log);
+	error = ovs_nla_copy_actions(net, a[OVS_FLOW_ATTR_ACTIONS],
+				     &new_flow->key, &acts, log);
 	if (error) {
 		OVS_NLERR(log, "Flow actions may not be safe on all matching packets.");
 		goto err_kfree_flow;
@@ -944,7 +976,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	ovs_lock();
-	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	dp = get_dp(net, ovs_header->dp_ifindex);
 	if (unlikely(!dp)) {
 		error = -ENODEV;
 		goto err_unlock_ovs;
@@ -1038,7 +1070,8 @@ error:
 }
 
 /* Factor out action copy to avoid "Wframe-larger-than=1024" warning. */
-static struct sw_flow_actions *get_flow_actions(const struct nlattr *a,
+static struct sw_flow_actions *get_flow_actions(struct net *net,
+						const struct nlattr *a,
 						const struct sw_flow_key *key,
 						const struct sw_flow_mask *mask,
 						bool log)
@@ -1048,7 +1081,7 @@ static struct sw_flow_actions *get_flow_actions(const struct nlattr *a,
 	int error;
 
 	ovs_flow_mask_key(&masked_key, key, mask);
-	error = ovs_nla_copy_actions(a, &masked_key, &acts, log);
+	error = ovs_nla_copy_actions(net, a, &masked_key, &acts, log);
 	if (error) {
 		OVS_NLERR(log,
 			  "Actions may not be safe on all matching packets");
@@ -1060,6 +1093,7 @@ static struct sw_flow_actions *get_flow_actions(const struct nlattr *a,
 
 static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 {
+	struct net *net = sock_net(skb->sk);
 	struct nlattr **a = info->attrs;
 	struct ovs_header *ovs_header = info->userhdr;
 	struct sw_flow_key key;
@@ -1091,8 +1125,8 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 
 	/* Validate actions. */
 	if (a[OVS_FLOW_ATTR_ACTIONS]) {
-		acts = get_flow_actions(a[OVS_FLOW_ATTR_ACTIONS], &key, &mask,
-					log);
+		acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], &key,
+					&mask, log);
 		if (IS_ERR(acts)) {
 			error = PTR_ERR(acts);
 			goto error;
@@ -1108,7 +1142,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	ovs_lock();
-	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	dp = get_dp(net, ovs_header->dp_ifindex);
 	if (unlikely(!dp)) {
 		error = -ENODEV;
 		goto err_unlock_ovs;
diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h
index 487a85f7d967..d24ba98024be 100644
--- a/net/openvswitch/datapath.h
+++ b/net/openvswitch/datapath.h
@@ -27,6 +27,7 @@
 #include <linux/u64_stats_sync.h>
 #include <net/ip_tunnels.h>
 
+#include "conntrack.h"
 #include "flow.h"
 #include "flow_table.h"
 #include "vport.h"
@@ -97,10 +98,13 @@ struct datapath {
  * NULL if the packet is not being tunneled.
  * @input_vport: The original vport packet came in on. This value is cached
  * when a packet is received by OVS.
+ * @mru: The maximum received fragement size; 0 if the packet is not
+ * fragmented.
  */
 struct ovs_skb_cb {
 	struct ip_tunnel_info  *egress_tun_info;
 	struct vport		*input_vport;
+	u16			mru;
 };
 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 
@@ -113,6 +117,7 @@ struct ovs_skb_cb {
  * then no packet is sent and the packet is accounted in the datapath's @n_lost
  * counter.
  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
+ * @mru: If not zero, Maximum received IP fragment size.
  */
 struct dp_upcall_info {
 	const struct ip_tunnel_info *egress_tun_info;
@@ -121,6 +126,7 @@ struct dp_upcall_info {
 	int actions_len;
 	u32 portid;
 	u8 cmd;
+	u16 mru;
 };
 
 /**
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 8db22ef73626..376ca8738fd4 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -49,6 +49,7 @@
 #include "datapath.h"
 #include "flow.h"
 #include "flow_netlink.h"
+#include "conntrack.h"
 
 u64 ovs_flow_used_time(unsigned long flow_jiffies)
 {
@@ -707,6 +708,7 @@ int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
 	key->phy.priority = skb->priority;
 	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
 	key->phy.skb_mark = skb->mark;
+	ovs_ct_fill_key(skb, key);
 	key->ovs_flow_hash = 0;
 	key->recirc_id = 0;
 
diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h
index 082a87bac819..312c7d755b9b 100644
--- a/net/openvswitch/flow.h
+++ b/net/openvswitch/flow.h
@@ -111,6 +111,12 @@ struct sw_flow_key {
 			} nd;
 		} ipv6;
 	};
+	struct {
+		/* Connection tracking fields. */
+		u16 zone;
+		u8 state;
+	} ct;
+
 } __aligned(BITS_PER_LONG/8); /* Ensure that we can do comparisons as longs. */
 
 struct sw_flow_key_range {
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index c182b28c0884..4e795b289eb7 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -281,7 +281,7 @@ size_t ovs_key_attr_size(void)
 	/* Whenever adding new OVS_KEY_ FIELDS, we should consider
 	 * updating this function.
 	 */
-	BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 22);
+	BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 24);
 
 	return    nla_total_size(4)   /* OVS_KEY_ATTR_PRIORITY */
 		+ nla_total_size(0)   /* OVS_KEY_ATTR_TUNNEL */
@@ -290,6 +290,8 @@ size_t ovs_key_attr_size(void)
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_SKB_MARK */
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_DP_HASH */
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_RECIRC_ID */
+		+ nla_total_size(1)   /* OVS_KEY_ATTR_CT_STATE */
+		+ nla_total_size(2)   /* OVS_KEY_ATTR_CT_ZONE */
 		+ nla_total_size(12)  /* OVS_KEY_ATTR_ETHERNET */
 		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_VLAN */
@@ -339,6 +341,8 @@ static const struct ovs_len_tbl ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
 	[OVS_KEY_ATTR_TUNNEL]	 = { .len = OVS_ATTR_NESTED,
 				     .next = ovs_tunnel_key_lens, },
 	[OVS_KEY_ATTR_MPLS]	 = { .len = sizeof(struct ovs_key_mpls) },
+	[OVS_KEY_ATTR_CT_STATE]	 = { .len = sizeof(u8) },
+	[OVS_KEY_ATTR_CT_ZONE]	 = { .len = sizeof(u16) },
 };
 
 static bool is_all_zero(const u8 *fp, size_t size)
@@ -768,6 +772,21 @@ static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
 			return -EINVAL;
 		*attrs &= ~(1 << OVS_KEY_ATTR_TUNNEL);
 	}
+
+	if (*attrs & (1 << OVS_KEY_ATTR_CT_STATE) &&
+	    ovs_ct_verify(OVS_KEY_ATTR_CT_STATE)) {
+		u8 ct_state = nla_get_u8(a[OVS_KEY_ATTR_CT_STATE]);
+
+		SW_FLOW_KEY_PUT(match, ct.state, ct_state, is_mask);
+		*attrs &= ~(1ULL << OVS_KEY_ATTR_CT_STATE);
+	}
+	if (*attrs & (1 << OVS_KEY_ATTR_CT_ZONE) &&
+	    ovs_ct_verify(OVS_KEY_ATTR_CT_ZONE)) {
+		u16 ct_zone = nla_get_u16(a[OVS_KEY_ATTR_CT_ZONE]);
+
+		SW_FLOW_KEY_PUT(match, ct.zone, ct_zone, is_mask);
+		*attrs &= ~(1ULL << OVS_KEY_ATTR_CT_ZONE);
+	}
 	return 0;
 }
 
@@ -1266,6 +1285,7 @@ int ovs_nla_get_flow_metadata(const struct nlattr *attr,
 	memset(&match, 0, sizeof(match));
 	match.key = key;
 
+	memset(&key->ct, 0, sizeof(key->ct));
 	key->phy.in_port = DP_MAX_PORTS;
 
 	return metadata_from_nlattrs(&match, &attrs, a, false, log);
@@ -1314,6 +1334,9 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
 	if (nla_put_u32(skb, OVS_KEY_ATTR_SKB_MARK, output->phy.skb_mark))
 		goto nla_put_failure;
 
+	if (ovs_ct_put_key(output, skb))
+		goto nla_put_failure;
+
 	nla = nla_reserve(skb, OVS_KEY_ATTR_ETHERNET, sizeof(*eth_key));
 	if (!nla)
 		goto nla_put_failure;
@@ -1574,6 +1597,9 @@ void ovs_nla_free_flow_actions(struct sw_flow_actions *sf_acts)
 		case OVS_ACTION_ATTR_SET:
 			ovs_nla_free_set_action(a);
 			break;
+		case OVS_ACTION_ATTR_CT:
+			ovs_ct_free_action(a);
+			break;
 		}
 	}
 
@@ -1647,8 +1673,8 @@ static struct nlattr *__add_action(struct sw_flow_actions **sfa,
 	return a;
 }
 
-static int add_action(struct sw_flow_actions **sfa, int attrtype,
-		      void *data, int len, bool log)
+int ovs_nla_add_action(struct sw_flow_actions **sfa, int attrtype, void *data,
+		       int len, bool log)
 {
 	struct nlattr *a;
 
@@ -1663,7 +1689,7 @@ static inline int add_nested_action_start(struct sw_flow_actions **sfa,
 	int used = (*sfa)->actions_len;
 	int err;
 
-	err = add_action(sfa, attrtype, NULL, 0, log);
+	err = ovs_nla_add_action(sfa, attrtype, NULL, 0, log);
 	if (err)
 		return err;
 
@@ -1679,12 +1705,12 @@ static inline void add_nested_action_end(struct sw_flow_actions *sfa,
 	a->nla_len = sfa->actions_len - st_offset;
 }
 
-static int __ovs_nla_copy_actions(const struct nlattr *attr,
+static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 				  const struct sw_flow_key *key,
 				  int depth, struct sw_flow_actions **sfa,
 				  __be16 eth_type, __be16 vlan_tci, bool log);
 
-static int validate_and_copy_sample(const struct nlattr *attr,
+static int validate_and_copy_sample(struct net *net, const struct nlattr *attr,
 				    const struct sw_flow_key *key, int depth,
 				    struct sw_flow_actions **sfa,
 				    __be16 eth_type, __be16 vlan_tci, bool log)
@@ -1716,15 +1742,15 @@ static int validate_and_copy_sample(const struct nlattr *attr,
 	start = add_nested_action_start(sfa, OVS_ACTION_ATTR_SAMPLE, log);
 	if (start < 0)
 		return start;
-	err = add_action(sfa, OVS_SAMPLE_ATTR_PROBABILITY,
-			 nla_data(probability), sizeof(u32), log);
+	err = ovs_nla_add_action(sfa, OVS_SAMPLE_ATTR_PROBABILITY,
+				 nla_data(probability), sizeof(u32), log);
 	if (err)
 		return err;
 	st_acts = add_nested_action_start(sfa, OVS_SAMPLE_ATTR_ACTIONS, log);
 	if (st_acts < 0)
 		return st_acts;
 
-	err = __ovs_nla_copy_actions(actions, key, depth + 1, sfa,
+	err = __ovs_nla_copy_actions(net, actions, key, depth + 1, sfa,
 				     eth_type, vlan_tci, log);
 	if (err)
 		return err;
@@ -2058,7 +2084,7 @@ static int copy_action(const struct nlattr *from,
 	return 0;
 }
 
-static int __ovs_nla_copy_actions(const struct nlattr *attr,
+static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 				  const struct sw_flow_key *key,
 				  int depth, struct sw_flow_actions **sfa,
 				  __be16 eth_type, __be16 vlan_tci, bool log)
@@ -2082,7 +2108,8 @@ static int __ovs_nla_copy_actions(const struct nlattr *attr,
 			[OVS_ACTION_ATTR_SET] = (u32)-1,
 			[OVS_ACTION_ATTR_SET_MASKED] = (u32)-1,
 			[OVS_ACTION_ATTR_SAMPLE] = (u32)-1,
-			[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash)
+			[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash),
+			[OVS_ACTION_ATTR_CT] = (u32)-1,
 		};
 		const struct ovs_action_push_vlan *vlan;
 		int type = nla_type(a);
@@ -2189,13 +2216,20 @@ static int __ovs_nla_copy_actions(const struct nlattr *attr,
 			break;
 
 		case OVS_ACTION_ATTR_SAMPLE:
-			err = validate_and_copy_sample(a, key, depth, sfa,
+			err = validate_and_copy_sample(net, a, key, depth, sfa,
 						       eth_type, vlan_tci, log);
 			if (err)
 				return err;
 			skip_copy = true;
 			break;
 
+		case OVS_ACTION_ATTR_CT:
+			err = ovs_ct_copy_action(net, a, key, sfa, log);
+			if (err)
+				return err;
+			skip_copy = true;
+			break;
+
 		default:
 			OVS_NLERR(log, "Unknown Action type %d", type);
 			return -EINVAL;
@@ -2214,7 +2248,7 @@ static int __ovs_nla_copy_actions(const struct nlattr *attr,
 }
 
 /* 'key' must be the masked key. */
-int ovs_nla_copy_actions(const struct nlattr *attr,
+int ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 			 const struct sw_flow_key *key,
 			 struct sw_flow_actions **sfa, bool log)
 {
@@ -2225,7 +2259,7 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
 		return PTR_ERR(*sfa);
 
 	(*sfa)->orig_len = nla_len(attr);
-	err = __ovs_nla_copy_actions(attr, key, 0, sfa, key->eth.type,
+	err = __ovs_nla_copy_actions(net, attr, key, 0, sfa, key->eth.type,
 				     key->eth.tci, log);
 	if (err)
 		ovs_nla_free_flow_actions(*sfa);
@@ -2350,6 +2384,13 @@ int ovs_nla_put_actions(const struct nlattr *attr, int len, struct sk_buff *skb)
 			if (err)
 				return err;
 			break;
+
+		case OVS_ACTION_ATTR_CT:
+			err = ovs_ct_action_to_attr(nla_data(a), skb);
+			if (err)
+				return err;
+			break;
+
 		default:
 			if (nla_put(skb, type, nla_len(a), nla_data(a)))
 				return -EMSGSIZE;
diff --git a/net/openvswitch/flow_netlink.h b/net/openvswitch/flow_netlink.h
index acd074408f0a..c0b484b237c9 100644
--- a/net/openvswitch/flow_netlink.h
+++ b/net/openvswitch/flow_netlink.h
@@ -62,9 +62,11 @@ int ovs_nla_get_identifier(struct sw_flow_id *sfid, const struct nlattr *ufid,
 			   const struct sw_flow_key *key, bool log);
 u32 ovs_nla_get_ufid_flags(const struct nlattr *attr);
 
-int ovs_nla_copy_actions(const struct nlattr *attr,
+int ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 			 const struct sw_flow_key *key,
 			 struct sw_flow_actions **sfa, bool log);
+int ovs_nla_add_action(struct sw_flow_actions **sfa, int attrtype,
+		       void *data, int len, bool log);
 int ovs_nla_put_actions(const struct nlattr *attr,
 			int len, struct sk_buff *skb);
 
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index d73e5a16e7ca..e2dc9dac59e6 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -484,6 +484,7 @@ void ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 
 	OVS_CB(skb)->input_vport = vport;
 	OVS_CB(skb)->egress_tun_info = NULL;
+	OVS_CB(skb)->mru = 0;
 	/* Extract flow from 'skb' into 'key'. */
 	error = ovs_flow_key_extract(tun_info, skb, &key);
 	if (unlikely(error)) {