diff --git a/acinclude.m4 b/acinclude.m4
index 874bf57b287d..9d652c2aed13 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -477,6 +477,8 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [IP6_FH_F_SKIP_RH])
   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [ip6_local_out_sk])
   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [__ipv6_addr_jhash])
+  OVS_GREP_IFELSE([$KSRC/include/net/ip6_fib.h], [rt6i.*u.dst],
+                  [OVS_DEFINE([HAVE_RT6INFO_DST_UNION])])
   OVS_GREP_IFELSE([$KSRC/include/net/ip6_route.h], [ip6_frag.*sock],
                   [OVS_DEFINE([HAVE_IP_FRAGMENT_TAKES_SOCK])])
 
diff --git a/datapath/Modules.mk b/datapath/Modules.mk
index c06eafc1e3b1..3ffeee2ae7e2 100644
--- a/datapath/Modules.mk
+++ b/datapath/Modules.mk
@@ -18,6 +18,7 @@ dist_modules = $(both_modules)	# Modules to distribute
 
 openvswitch_sources = \
 	actions.c \
+	conntrack.c \
 	datapath.c \
 	dp_notify.c \
 	flow.c \
@@ -35,6 +36,7 @@ vport_stt_sources = vport-stt.c
 
 openvswitch_headers = \
 	compat.h \
+	conntrack.h \
 	datapath.h \
 	flow.h \
 	flow_netlink.h \
diff --git a/datapath/actions.c b/datapath/actions.c
index 0397bfe3dba4..0625d7e01176 100644
--- a/datapath/actions.c
+++ b/datapath/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>
@@ -37,6 +39,7 @@
 #include <net/sctp/checksum.h>
 
 #include "datapath.h"
+#include "conntrack.h"
 #include "gso.h"
 #include "vlan.h"
 #include "vport.h"
@@ -53,6 +56,20 @@ 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;
@@ -606,14 +623,157 @@ 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)
+#if LINUX_VERSION_CODE > KERNEL_VERSION(3,9,0)
+static int ovs_vport_output(OVS_VPORT_OUTPUT_PARAMS)
+{
+	struct ovs_frag_data *data = get_pcpu_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;
+	ovs_skb_set_inner_protocol(skb, 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 = get_pcpu_ptr(ovs_frag_data_storage);
+	data->dst = (unsigned long) skb_dst(skb);
+	data->vport = vport;
+	data->cb = *OVS_CB(skb);
+	data->inner_protocol = ovs_skb_get_inner_protocol(skb);
+	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 = (unsigned long) skb_dst(skb);
+		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 = (unsigned long) skb_dst(skb);
+		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);
+	}
+}
+#else /* <= 3.9 */
+static void ovs_fragment(struct vport *vport, struct sk_buff *skb, u16 mru,
+			 __be16 ethertype)
+{
+	WARN_ONCE(1, "Fragment unavailable ->%s: eth=%04x, MRU=%d, MTU=%d.",
+		  ovs_vport_name(vport), ntohs(ethertype), mru,
+		  vport->dev->mtu);
+	kfree_skb(skb);
+}
+#endif
+
+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 = ovs_skb_get_inner_protocol(skb);
+				else
+					ethertype = vlan_get_protocol(skb);
+			}
+
+			ovs_fragment(vport, skb, mru, ethertype);
+		} else {
+			OVS_NLERR(true, "Cannot fragment IP frames");
+			kfree_skb(skb);
+		}
+	} else {
 		kfree_skb(skb);
+	}
 }
 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 			    struct sw_flow_key *key, const struct nlattr *attr,
@@ -626,6 +786,7 @@ 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)) {
@@ -817,6 +978,11 @@ 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;
@@ -886,7 +1052,7 @@ 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;
 		}
@@ -943,6 +1109,15 @@ 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)) {
@@ -952,7 +1127,7 @@ 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/datapath/conntrack.c b/datapath/conntrack.c
new file mode 100644
index 000000000000..71312becd228
--- /dev/null
+++ b/datapath/conntrack.c
@@ -0,0 +1,467 @@
+/*
+ * 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/kconfig.h>
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE > KERNEL_VERSION(3,9,0) && \
+    IS_ENABLED(CONFIG_NF_CONNTRACK)
+
+#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 (!skb->dev) {
+		OVS_NLERR(true, "%s: skb has no dev; dropping", __func__);
+		return -EINVAL;
+	}
+
+	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 /* IP frag support */
+	} 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_FORWARD,
+				    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_tmpl_free(ct_info->ct);
+}
+
+#endif /* CONFIG_NF_CONNTRACK && LINUX > 3.9 */
diff --git a/datapath/conntrack.h b/datapath/conntrack.h
new file mode 100644
index 000000000000..11320fa24343
--- /dev/null
+++ b/datapath/conntrack.h
@@ -0,0 +1,79 @@
+/*
+ * 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 <linux/version.h>
+#include "flow.h"
+
+struct ovs_conntrack_info;
+enum ovs_key_attr;
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK) && LINUX_VERSION_CODE > KERNEL_VERSION(3,9,0)
+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/datapath/datapath.c b/datapath/datapath.c
index 9e6f6147d407..32644453fd5f 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -279,6 +279,7 @@ 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);
@@ -404,9 +405,23 @@ 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)
@@ -502,6 +517,16 @@ 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()
 	 */
@@ -516,12 +541,7 @@ 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;
 
@@ -538,6 +558,7 @@ 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;
@@ -546,6 +567,7 @@ 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];
@@ -576,6 +598,13 @@ 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);
@@ -587,7 +616,7 @@ 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;
@@ -597,7 +626,7 @@ 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;
@@ -636,6 +665,7 @@ 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 struct genl_ops dp_packet_genl_ops[] = {
@@ -893,6 +923,7 @@ 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;
@@ -942,8 +973,8 @@ 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;
@@ -957,7 +988,7 @@ 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;
@@ -1051,7 +1082,8 @@ 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)
@@ -1061,7 +1093,7 @@ static struct sw_flow_actions *get_flow_actions(const struct nlattr *a,
 	int error;
 
 	ovs_flow_mask_key(&masked_key, key, true, 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");
@@ -1073,6 +1105,7 @@ 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;
@@ -1104,8 +1137,8 @@ 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;
@@ -1121,7 +1154,7 @@ 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/datapath/datapath.h b/datapath/datapath.h
index 9f3d7b2da60b..a3ba8865a9f9 100644
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -97,9 +97,12 @@ struct datapath {
  * struct ovs_skb_cb - OVS data in skb CB
  * @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 vport		*input_vport;
+	u16			mru;
 };
 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 
@@ -112,6 +115,7 @@ 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 {
 	struct ip_tunnel_info *egress_tun_info;
@@ -121,6 +125,7 @@ struct dp_upcall_info {
 	int actions_len;
 	u32 portid;
 	u8 cmd;
+	u16 mru;
 };
 
 /**
diff --git a/datapath/flow.c b/datapath/flow.c
index 3375d7b4db03..78f974eca087 100644
--- a/datapath/flow.c
+++ b/datapath/flow.c
@@ -46,6 +46,7 @@
 #include <net/ndisc.h>
 
 #include "datapath.h"
+#include "conntrack.h"
 #include "flow.h"
 #include "flow_netlink.h"
 #include "vport.h"
@@ -711,6 +712,7 @@ 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/datapath/flow.h b/datapath/flow.h
index 61fa708451d7..08c236e8053e 100644
--- a/datapath/flow.h
+++ b/datapath/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/datapath/flow_netlink.c b/datapath/flow_netlink.c
index c62964897cff..88649019e27d 100644
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -48,6 +48,7 @@
 #include <net/vxlan.h>
 
 #include "datapath.h"
+#include "conntrack.h"
 #include "flow.h"
 #include "flow_netlink.h"
 
@@ -291,6 +292,8 @@ 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 */
@@ -345,6 +348,8 @@ 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 check_attr_len(unsigned int attr_len, unsigned int expected_len)
@@ -803,6 +808,21 @@ static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
 			return -EINVAL;
 		*attrs &= ~(1ULL << 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;
 }
 
@@ -1306,6 +1326,7 @@ int ovs_nla_get_flow_metadata(const struct nlattr *attr,
 	match.key = key;
 
 	memset(key, 0, OVS_SW_FLOW_KEY_METADATA_SIZE);
+	memset(&key->ct, 0, sizeof(key->ct));
 	key->phy.in_port = DP_MAX_PORTS;
 
 	return metadata_from_nlattrs(&match, &attrs, a, false, log);
@@ -1354,6 +1375,9 @@ 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;
@@ -1614,6 +1638,9 @@ 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;
 		}
 	}
 
@@ -1688,8 +1715,8 @@ 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;
 
@@ -1706,7 +1733,7 @@ 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;
 
@@ -1722,12 +1749,12 @@ 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)
@@ -1759,15 +1786,15 @@ 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;
@@ -2094,7 +2121,7 @@ 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)
@@ -2118,7 +2145,8 @@ 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);
@@ -2225,13 +2253,20 @@ 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;
@@ -2250,7 +2285,7 @@ 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)
 {
@@ -2261,7 +2296,7 @@ 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);
@@ -2380,6 +2415,13 @@ 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/datapath/flow_netlink.h b/datapath/flow_netlink.h
index 140bbe7077a1..74d8dc6bce09 100644
--- a/datapath/flow_netlink.h
+++ b/datapath/flow_netlink.h
@@ -63,9 +63,11 @@ 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/datapath/linux/compat/include/linux/percpu.h b/datapath/linux/compat/include/linux/percpu.h
index 2459f55b3bf9..f9fcabb5f4fc 100644
--- a/datapath/linux/compat/include/linux/percpu.h
+++ b/datapath/linux/compat/include/linux/percpu.h
@@ -25,4 +25,10 @@
 #define this_cpu_dec(ptr) percpu_sub(ptr, 1)
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,34)
+#define get_pcpu_ptr(name) ((void *)this_cpu_ptr(&__pcpu_unique_##name))
+#else
+#define get_pcpu_ptr(name) (this_cpu_ptr(&name))
+#endif
+
 #endif
diff --git a/datapath/vport.c b/datapath/vport.c
index 1e22c6d483a0..0951cbbdb4e6 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -493,6 +493,7 @@ int ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 	int error;
 
 	OVS_CB(skb)->input_vport = vport;
+	OVS_CB(skb)->mru = 0;
 	ovs_skb_init_inner_protocol(skb);
 	skb_clear_ovs_gso_cb(skb);
 	/* Extract flow from 'skb' into 'key'. */
