1 files changed, 790 insertions, 0 deletions

diff --git a/kernel/net/openvswitch/conntrack.c b/kernel/net/openvswitch/conntrack.c
new file mode 100644
index 000000000..e004067ec
--- /dev/null
+++ b/kernel/net/openvswitch/conntrack.c
@@ -0,0 +1,790 @@
+/*
+ * 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_helper.h>
+#include <net/netfilter/nf_conntrack_labels.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;
+};
+
+/* Metadata mark for masked write to conntrack mark */
+struct md_mark {
+	u32 value;
+	u32 mask;
+};
+
+/* Metadata label for masked write to conntrack label. */
+struct md_labels {
+	struct ovs_key_ct_labels value;
+	struct ovs_key_ct_labels mask;
+};
+
+/* Conntrack action context for execution. */
+struct ovs_conntrack_info {
+	struct nf_conntrack_helper *helper;
+	struct nf_conntrack_zone zone;
+	struct nf_conn *ct;
+	u8 commit : 1;
+	u16 family;
+	struct md_mark mark;
+	struct md_labels labels;
+};
+
+static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
+
+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 u32 ovs_ct_get_mark(const struct nf_conn *ct)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
+	return ct ? ct->mark : 0;
+#else
+	return 0;
+#endif
+}
+
+static void ovs_ct_get_labels(const struct nf_conn *ct,
+			      struct ovs_key_ct_labels *labels)
+{
+	struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
+
+	if (cl) {
+		size_t len = cl->words * sizeof(long);
+
+		if (len > OVS_CT_LABELS_LEN)
+			len = OVS_CT_LABELS_LEN;
+		else if (len < OVS_CT_LABELS_LEN)
+			memset(labels, 0, OVS_CT_LABELS_LEN);
+		memcpy(labels, cl->bits, len);
+	} else {
+		memset(labels, 0, OVS_CT_LABELS_LEN);
+	}
+}
+
+static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
+				const struct nf_conntrack_zone *zone,
+				const struct nf_conn *ct)
+{
+	key->ct.state = state;
+	key->ct.zone = zone->id;
+	key->ct.mark = ovs_ct_get_mark(ct);
+	ovs_ct_get_labels(ct, &key->ct.labels);
+}
+
+/* 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,
+			      const struct ovs_conntrack_info *info,
+			      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 (!nf_ct_is_confirmed(ct))
+			state |= OVS_CS_F_NEW;
+		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;
+		if (info)
+			zone = &info->zone;
+	}
+	__ovs_ct_update_key(key, state, zone, ct);
+}
+
+void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
+{
+	ovs_ct_update_key(skb, NULL, key, false);
+}
+
+int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
+{
+	if (nla_put_u32(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;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
+	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
+		return -EMSGSIZE;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
+	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
+		    &key->ct.labels))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
+			   u32 ct_mark, u32 mask)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	u32 new_mark;
+
+
+	/* The connection could be invalid, in which case set_mark is no-op. */
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		return 0;
+
+	new_mark = ct_mark | (ct->mark & ~(mask));
+	if (ct->mark != new_mark) {
+		ct->mark = new_mark;
+		nf_conntrack_event_cache(IPCT_MARK, ct);
+		key->ct.mark = new_mark;
+	}
+
+	return 0;
+#else
+	return -ENOTSUPP;
+#endif
+}
+
+static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
+			     const struct ovs_key_ct_labels *labels,
+			     const struct ovs_key_ct_labels *mask)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn_labels *cl;
+	struct nf_conn *ct;
+	int err;
+
+	/* The connection could be invalid, in which case set_label is no-op.*/
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		return 0;
+
+	cl = nf_ct_labels_find(ct);
+	if (!cl) {
+		nf_ct_labels_ext_add(ct);
+		cl = nf_ct_labels_find(ct);
+	}
+	if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
+		return -ENOSPC;
+
+	err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
+				    OVS_CT_LABELS_LEN / sizeof(u32));
+	if (err)
+		return err;
+
+	ovs_ct_get_labels(ct, &key->ct.labels);
+	return 0;
+}
+
+/* 'skb' should already be pulled to nh_ofs. */
+static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
+{
+	const struct nf_conntrack_helper *helper;
+	const struct nf_conn_help *help;
+	enum ip_conntrack_info ctinfo;
+	unsigned int protoff;
+	struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+		return NF_ACCEPT;
+
+	help = nfct_help(ct);
+	if (!help)
+		return NF_ACCEPT;
+
+	helper = rcu_dereference(help->helper);
+	if (!helper)
+		return NF_ACCEPT;
+
+	switch (proto) {
+	case NFPROTO_IPV4:
+		protoff = ip_hdrlen(skb);
+		break;
+	case NFPROTO_IPV6: {
+		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
+		__be16 frag_off;
+		int ofs;
+
+		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
+				       &frag_off);
+		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
+			pr_debug("proto header not found\n");
+			return NF_ACCEPT;
+		}
+		protoff = ofs;
+		break;
+	}
+	default:
+		WARN_ONCE(1, "helper invoked on non-IP family!");
+		return NF_DROP;
+	}
+
+	return helper->help(skb, protoff, ct, ctinfo);
+}
+
+/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
+ * value if 'skb' is freed.
+ */
+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(net, skb, user);
+		if (err)
+			return err;
+
+		ovs_cb.mru = IPCB(skb)->frag_max_size;
+#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
+	} else if (key->eth.type == htons(ETH_P_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(net, skb, user);
+		if (!reasm)
+			return -EINPROGRESS;
+
+		if (skb == reasm) {
+			kfree_skb(skb);
+			return -EINVAL;
+		}
+
+		/* Don't free 'skb' even though it is one of the original
+		 * fragments, as we're going to morph it into the head.
+		 */
+		skb_get(skb);
+		nf_ct_frag6_consume_orig(reasm);
+
+		key->ip.proto = ipv6_hdr(reasm)->nexthdr;
+		skb_morph(skb, reasm);
+		skb->next = reasm->next;
+		consume_skb(reasm);
+		ovs_cb.mru = IP6CB(skb)->frag_max_size;
+#endif
+	} else {
+		kfree_skb(skb);
+		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, net, &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;
+	if (info->helper) {
+		struct nf_conn_help *help;
+
+		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
+		if (help && rcu_access_pointer(help->helper) != info->helper)
+			return false;
+	}
+
+	return true;
+}
+
+static int __ovs_ct_lookup(struct net *net, 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;
+
+		if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
+			WARN_ONCE(1, "helper rejected packet");
+			return -EINVAL;
+		}
+	}
+
+	ovs_ct_update_key(skb, info, key, true);
+
+	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, exp->master);
+	} else {
+		int err;
+
+		err = __ovs_ct_lookup(net, key, info, skb);
+		if (err)
+			return err;
+	}
+
+	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;
+
+	return 0;
+}
+
+static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
+{
+	size_t i;
+
+	for (i = 0; i < sizeof(*labels); i++)
+		if (labels->ct_labels[i])
+			return true;
+
+	return false;
+}
+
+/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
+ * value if 'skb' is freed.
+ */
+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->commit)
+		err = ovs_ct_commit(net, key, info, skb);
+	else
+		err = ovs_ct_lookup(net, key, info, skb);
+	if (err)
+		goto err;
+
+	if (info->mark.mask) {
+		err = ovs_ct_set_mark(skb, key, info->mark.value,
+				      info->mark.mask);
+		if (err)
+			goto err;
+	}
+	if (labels_nonzero(&info->labels.mask))
+		err = ovs_ct_set_labels(skb, key, &info->labels.value,
+					&info->labels.mask);
+err:
+	skb_push(skb, nh_ofs);
+	if (err)
+		kfree_skb(skb);
+	return err;
+}
+
+static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
+			     const struct sw_flow_key *key, bool log)
+{
+	struct nf_conntrack_helper *helper;
+	struct nf_conn_help *help;
+
+	helper = nf_conntrack_helper_try_module_get(name, info->family,
+						    key->ip.proto);
+	if (!helper) {
+		OVS_NLERR(log, "Unknown helper \"%s\"", name);
+		return -EINVAL;
+	}
+
+	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
+	if (!help) {
+		module_put(helper->me);
+		return -ENOMEM;
+	}
+
+	rcu_assign_pointer(help->helper, helper);
+	info->helper = helper;
+	return 0;
+}
+
+static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
+	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
+	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
+				    .maxlen = sizeof(u16) },
+	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
+				    .maxlen = sizeof(struct md_mark) },
+	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
+				    .maxlen = sizeof(struct md_labels) },
+	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
+				    .maxlen = NF_CT_HELPER_NAME_LEN }
+};
+
+static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
+		    const char **helper, 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_COMMIT:
+			info->commit = true;
+			break;
+#ifdef CONFIG_NF_CONNTRACK_ZONES
+		case OVS_CT_ATTR_ZONE:
+			info->zone.id = nla_get_u16(a);
+			break;
+#endif
+#ifdef CONFIG_NF_CONNTRACK_MARK
+		case OVS_CT_ATTR_MARK: {
+			struct md_mark *mark = nla_data(a);
+
+			if (!mark->mask) {
+				OVS_NLERR(log, "ct_mark mask cannot be 0");
+				return -EINVAL;
+			}
+			info->mark = *mark;
+			break;
+		}
+#endif
+#ifdef CONFIG_NF_CONNTRACK_LABELS
+		case OVS_CT_ATTR_LABELS: {
+			struct md_labels *labels = nla_data(a);
+
+			if (!labels_nonzero(&labels->mask)) {
+				OVS_NLERR(log, "ct_labels mask cannot be 0");
+				return -EINVAL;
+			}
+			info->labels = *labels;
+			break;
+		}
+#endif
+		case OVS_CT_ATTR_HELPER:
+			*helper = nla_data(a);
+			if (!memchr(*helper, '\0', nla_len(a))) {
+				OVS_NLERR(log, "Invalid conntrack helper");
+				return -EINVAL;
+			}
+			break;
+		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(struct net *net, 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;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
+	    attr == OVS_KEY_ATTR_CT_MARK)
+		return true;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
+	    attr == OVS_KEY_ATTR_CT_LABELS) {
+		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
+
+		return ovs_net->xt_label;
+	}
+
+	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;
+	const char *helper = NULL;
+	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, &helper, 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;
+	}
+
+	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
+	nf_conntrack_get(&ct_info.ct->ct_general);
+
+	if (helper) {
+		err = ovs_ct_add_helper(&ct_info, helper, key, log);
+		if (err)
+			goto err_free_ct;
+	}
+
+	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
+				 sizeof(ct_info), log);
+	if (err)
+		goto err_free_ct;
+
+	return 0;
+err_free_ct:
+	__ovs_ct_free_action(&ct_info);
+	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 (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
+		return -EMSGSIZE;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
+	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
+		return -EMSGSIZE;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
+	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
+		    &ct_info->mark))
+		return -EMSGSIZE;
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
+	    labels_nonzero(&ct_info->labels.mask) &&
+	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
+		    &ct_info->labels))
+		return -EMSGSIZE;
+	if (ct_info->helper) {
+		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
+				   ct_info->helper->name))
+			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);
+
+	__ovs_ct_free_action(ct_info);
+}
+
+static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
+{
+	if (ct_info->helper)
+		module_put(ct_info->helper->me);
+	if (ct_info->ct)
+		nf_ct_put(ct_info->ct);
+}
+
+void ovs_ct_init(struct net *net)
+{
+	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
+	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
+
+	if (nf_connlabels_get(net, n_bits)) {
+		ovs_net->xt_label = false;
+		OVS_NLERR(true, "Failed to set connlabel length");
+	} else {
+		ovs_net->xt_label = true;
+	}
+}
+
+void ovs_ct_exit(struct net *net)
+{
+	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
+
+	if (ovs_net->xt_label)
+		nf_connlabels_put(net);
+}