Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2326 insertions, 0 deletions

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
new file mode 100644
index 000000000..0591cfb28
--- /dev/null
+++ b/net/openvswitch/conntrack.c
@@ -0,0 +1,2326 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015 Nicira, Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/openvswitch.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/sctp.h>
+#include <linux/static_key.h>
+#include <net/ip.h>
+#include <net/genetlink.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_count.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_labels.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
+#include <net/netfilter/nf_conntrack_timeout.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
+#include <net/ipv6_frag.h>
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+#include <net/netfilter/nf_nat.h>
+#endif
+
+#include <net/netfilter/nf_conntrack_act_ct.h>
+
+#include "datapath.h"
+#include "conntrack.h"
+#include "flow.h"
+#include "flow_netlink.h"
+
+struct ovs_ct_len_tbl {
+	int maxlen;
+	int 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;
+};
+
+enum ovs_ct_nat {
+	OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
+	OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
+	OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
+};
+
+/* 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;
+	u8 nat : 3;                 /* enum ovs_ct_nat */
+	u8 force : 1;
+	u8 have_eventmask : 1;
+	u16 family;
+	u32 eventmask;              /* Mask of 1 << IPCT_*. */
+	struct md_mark mark;
+	struct md_labels labels;
+	char timeout[CTNL_TIMEOUT_NAME_MAX];
+	struct nf_ct_timeout *nf_ct_timeout;
+#if IS_ENABLED(CONFIG_NF_NAT)
+	struct nf_nat_range2 range;  /* Only present for SRC NAT and DST NAT. */
+#endif
+};
+
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+#define OVS_CT_LIMIT_UNLIMITED	0
+#define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
+#define CT_LIMIT_HASH_BUCKETS 512
+static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);
+
+struct ovs_ct_limit {
+	/* Elements in ovs_ct_limit_info->limits hash table */
+	struct hlist_node hlist_node;
+	struct rcu_head rcu;
+	u16 zone;
+	u32 limit;
+};
+
+struct ovs_ct_limit_info {
+	u32 default_limit;
+	struct hlist_head *limits;
+	struct nf_conncount_data *data;
+};
+
+static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
+	[OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
+};
+#endif
+
+static bool labels_nonzero(const struct ovs_key_ct_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:
+		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:
+		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 ? READ_ONCE(ct->mark) : 0;
+#else
+	return 0;
+#endif
+}
+
+/* Guard against conntrack labels max size shrinking below 128 bits. */
+#if NF_CT_LABELS_MAX_SIZE < 16
+#error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
+#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)
+		memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
+	else
+		memset(labels, 0, OVS_CT_LABELS_LEN);
+}
+
+static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
+					const struct nf_conntrack_tuple *orig,
+					u8 icmp_proto)
+{
+	key->ct_orig_proto = orig->dst.protonum;
+	if (orig->dst.protonum == icmp_proto) {
+		key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
+		key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
+	} else {
+		key->ct.orig_tp.src = orig->src.u.all;
+		key->ct.orig_tp.dst = orig->dst.u.all;
+	}
+}
+
+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);
+
+	if (ct) {
+		const struct nf_conntrack_tuple *orig;
+
+		/* Use the master if we have one. */
+		if (ct->master)
+			ct = ct->master;
+		orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+
+		/* IP version must match with the master connection. */
+		if (key->eth.type == htons(ETH_P_IP) &&
+		    nf_ct_l3num(ct) == NFPROTO_IPV4) {
+			key->ipv4.ct_orig.src = orig->src.u3.ip;
+			key->ipv4.ct_orig.dst = orig->dst.u3.ip;
+			__ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
+			return;
+		} else if (key->eth.type == htons(ETH_P_IPV6) &&
+			   !sw_flow_key_is_nd(key) &&
+			   nf_ct_l3num(ct) == NFPROTO_IPV6) {
+			key->ipv6.ct_orig.src = orig->src.u3.in6;
+			key->ipv6.ct_orig.dst = orig->dst.u3.in6;
+			__ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
+			return;
+		}
+	}
+	/* Clear 'ct_orig_proto' to mark the non-existence of conntrack
+	 * original direction key fields.
+	 */
+	key->ct_orig_proto = 0;
+}
+
+/* Update 'key' based on skb->_nfct.  If 'post_ct' is true, then OVS has
+ * previously sent the packet to conntrack via the ct action.  If
+ * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
+ * initialized from the connection status.
+ */
+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,
+			      bool keep_nat_flags)
+{
+	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);
+		/* All unconfirmed entries are NEW connections. */
+		if (!nf_ct_is_confirmed(ct))
+			state |= OVS_CS_F_NEW;
+		/* OVS persists the related flag for the duration of the
+		 * connection.
+		 */
+		if (ct->master)
+			state |= OVS_CS_F_RELATED;
+		if (keep_nat_flags) {
+			state |= key->ct_state & OVS_CS_F_NAT_MASK;
+		} else {
+			if (ct->status & IPS_SRC_NAT)
+				state |= OVS_CS_F_SRC_NAT;
+			if (ct->status & IPS_DST_NAT)
+				state |= OVS_CS_F_DST_NAT;
+		}
+		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);
+}
+
+/* This is called to initialize CT key fields possibly coming in from the local
+ * stack.
+ */
+void ovs_ct_fill_key(const struct sk_buff *skb,
+		     struct sw_flow_key *key,
+		     bool post_ct)
+{
+	ovs_ct_update_key(skb, NULL, key, post_ct, false);
+}
+
+int ovs_ct_put_key(const struct sw_flow_key *swkey,
+		   const struct sw_flow_key *output, struct sk_buff *skb)
+{
+	if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
+		return -EMSGSIZE;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
+	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
+		return -EMSGSIZE;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
+	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
+		return -EMSGSIZE;
+
+	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
+	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
+		    &output->ct.labels))
+		return -EMSGSIZE;
+
+	if (swkey->ct_orig_proto) {
+		if (swkey->eth.type == htons(ETH_P_IP)) {
+			struct ovs_key_ct_tuple_ipv4 orig;
+
+			memset(&orig, 0, sizeof(orig));
+			orig.ipv4_src = output->ipv4.ct_orig.src;
+			orig.ipv4_dst = output->ipv4.ct_orig.dst;
+			orig.src_port = output->ct.orig_tp.src;
+			orig.dst_port = output->ct.orig_tp.dst;
+			orig.ipv4_proto = output->ct_orig_proto;
+
+			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
+				    sizeof(orig), &orig))
+				return -EMSGSIZE;
+		} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
+			struct ovs_key_ct_tuple_ipv6 orig;
+
+			memset(&orig, 0, sizeof(orig));
+			memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
+			       sizeof(orig.ipv6_src));
+			memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
+			       sizeof(orig.ipv6_dst));
+			orig.src_port = output->ct.orig_tp.src;
+			orig.dst_port = output->ct.orig_tp.dst;
+			orig.ipv6_proto = output->ct_orig_proto;
+
+			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
+				    sizeof(orig), &orig))
+				return -EMSGSIZE;
+		}
+	}
+
+	return 0;
+}
+
+static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
+			   u32 ct_mark, u32 mask)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
+	u32 new_mark;
+
+	new_mark = ct_mark | (READ_ONCE(ct->mark) & ~(mask));
+	if (READ_ONCE(ct->mark) != new_mark) {
+		WRITE_ONCE(ct->mark, new_mark);
+		if (nf_ct_is_confirmed(ct))
+			nf_conntrack_event_cache(IPCT_MARK, ct);
+		key->ct.mark = new_mark;
+	}
+
+	return 0;
+#else
+	return -ENOTSUPP;
+#endif
+}
+
+static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
+{
+	struct nf_conn_labels *cl;
+
+	cl = nf_ct_labels_find(ct);
+	if (!cl) {
+		nf_ct_labels_ext_add(ct);
+		cl = nf_ct_labels_find(ct);
+	}
+
+	return cl;
+}
+
+/* Initialize labels for a new, yet to be committed conntrack entry.  Note that
+ * since the new connection is not yet confirmed, and thus no-one else has
+ * access to it's labels, we simply write them over.
+ */
+static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
+			      const struct ovs_key_ct_labels *labels,
+			      const struct ovs_key_ct_labels *mask)
+{
+	struct nf_conn_labels *cl, *master_cl;
+	bool have_mask = labels_nonzero(mask);
+
+	/* Inherit master's labels to the related connection? */
+	master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
+
+	if (!master_cl && !have_mask)
+		return 0;   /* Nothing to do. */
+
+	cl = ovs_ct_get_conn_labels(ct);
+	if (!cl)
+		return -ENOSPC;
+
+	/* Inherit the master's labels, if any. */
+	if (master_cl)
+		*cl = *master_cl;
+
+	if (have_mask) {
+		u32 *dst = (u32 *)cl->bits;
+		int i;
+
+		for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
+			dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
+				(labels->ct_labels_32[i]
+				 & mask->ct_labels_32[i]);
+	}
+
+	/* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
+	 * IPCT_LABEL bit is set in the event cache.
+	 */
+	nf_conntrack_event_cache(IPCT_LABEL, ct);
+
+	memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
+
+	return 0;
+}
+
+static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
+			     const struct ovs_key_ct_labels *labels,
+			     const struct ovs_key_ct_labels *mask)
+{
+	struct nf_conn_labels *cl;
+	int err;
+
+	cl = ovs_ct_get_conn_labels(ct);
+	if (!cl)
+		return -ENOSPC;
+
+	err = nf_connlabels_replace(ct, labels->ct_labels_32,
+				    mask->ct_labels_32,
+				    OVS_CT_LABELS_LEN_32);
+	if (err)
+		return err;
+
+	memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
+
+	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;
+	int err;
+
+	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;
+	}
+
+	err = helper->help(skb, protoff, ct, ctinfo);
+	if (err != NF_ACCEPT)
+		return err;
+
+	/* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
+	 * FTP with NAT) adusting the TCP payload size when mangling IP
+	 * addresses and/or port numbers in the text-based control connection.
+	 */
+	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
+	    !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
+		return NF_DROP;
+	return NF_ACCEPT;
+}
+
+/* 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);
+	int err;
+
+	if (key->eth.type == htons(ETH_P_IP)) {
+		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
+
+		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;
+
+		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
+		err = nf_ct_frag6_gather(net, skb, user);
+		if (err) {
+			if (err != -EINPROGRESS)
+				kfree_skb(skb);
+			return err;
+		}
+
+		key->ip.proto = ipv6_hdr(skb)->nexthdr;
+		ovs_cb.mru = IP6CB(skb)->frag_max_size;
+#endif
+	} else {
+		kfree_skb(skb);
+		return -EPFNOSUPPORT;
+	}
+
+	/* The key extracted from the fragment that completed this datagram
+	 * likely didn't have an L4 header, so regenerate it.
+	 */
+	ovs_flow_key_update_l3l4(skb, key);
+
+	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;
+	struct nf_conntrack_expect *exp;
+
+	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
+		return NULL;
+
+	exp = __nf_ct_expect_find(net, zone, &tuple);
+	if (exp) {
+		struct nf_conntrack_tuple_hash *h;
+
+		/* Delete existing conntrack entry, if it clashes with the
+		 * expectation.  This can happen since conntrack ALGs do not
+		 * check for clashes between (new) expectations and existing
+		 * conntrack entries.  nf_conntrack_in() will check the
+		 * expectations only if a conntrack entry can not be found,
+		 * which can lead to OVS finding the expectation (here) in the
+		 * init direction, but which will not be removed by the
+		 * nf_conntrack_in() call, if a matching conntrack entry is
+		 * found instead.  In this case all init direction packets
+		 * would be reported as new related packets, while reply
+		 * direction packets would be reported as un-related
+		 * established packets.
+		 */
+		h = nf_conntrack_find_get(net, zone, &tuple);
+		if (h) {
+			struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
+
+			nf_ct_delete(ct, 0, 0);
+			nf_ct_put(ct);
+		}
+	}
+
+	return exp;
+}
+
+/* This replicates logic from nf_conntrack_core.c that is not exported. */
+static enum ip_conntrack_info
+ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
+{
+	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
+
+	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
+		return IP_CT_ESTABLISHED_REPLY;
+	/* Once we've had two way comms, always ESTABLISHED. */
+	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
+		return IP_CT_ESTABLISHED;
+	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
+		return IP_CT_RELATED;
+	return IP_CT_NEW;
+}
+
+/* Find an existing connection which this packet belongs to without
+ * re-attributing statistics or modifying the connection state.  This allows an
+ * skb->_nfct lost due to an upcall to be recovered during actions execution.
+ *
+ * Must be called with rcu_read_lock.
+ *
+ * On success, populates skb->_nfct and returns the connection.  Returns NULL
+ * if there is no existing entry.
+ */
+static struct nf_conn *
+ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
+		     u8 l3num, struct sk_buff *skb, bool natted)
+{
+	struct nf_conntrack_tuple tuple;
+	struct nf_conntrack_tuple_hash *h;
+	struct nf_conn *ct;
+
+	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
+			       net, &tuple)) {
+		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
+		return NULL;
+	}
+
+	/* Must invert the tuple if skb has been transformed by NAT. */
+	if (natted) {
+		struct nf_conntrack_tuple inverse;
+
+		if (!nf_ct_invert_tuple(&inverse, &tuple)) {
+			pr_debug("ovs_ct_find_existing: Inversion failed!\n");
+			return NULL;
+		}
+		tuple = inverse;
+	}
+
+	/* look for tuple match */
+	h = nf_conntrack_find_get(net, zone, &tuple);
+	if (!h)
+		return NULL;   /* Not found. */
+
+	ct = nf_ct_tuplehash_to_ctrack(h);
+
+	/* Inverted packet tuple matches the reverse direction conntrack tuple,
+	 * select the other tuplehash to get the right 'ctinfo' bits for this
+	 * packet.
+	 */
+	if (natted)
+		h = &ct->tuplehash[!h->tuple.dst.dir];
+
+	nf_ct_set(skb, ct, ovs_ct_get_info(h));
+	return ct;
+}
+
+static
+struct nf_conn *ovs_ct_executed(struct net *net,
+				const struct sw_flow_key *key,
+				const struct ovs_conntrack_info *info,
+				struct sk_buff *skb,
+				bool *ct_executed)
+{
+	struct nf_conn *ct = NULL;
+
+	/* If no ct, check if we have evidence that an existing conntrack entry
+	 * might be found for this skb.  This happens when we lose a skb->_nfct
+	 * due to an upcall, or if the direction is being forced.  If the
+	 * connection was not confirmed, it is not cached and needs to be run
+	 * through conntrack again.
+	 */
+	*ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
+		       !(key->ct_state & OVS_CS_F_INVALID) &&
+		       (key->ct_zone == info->zone.id);
+
+	if (*ct_executed || (!key->ct_state && info->force)) {
+		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
+					  !!(key->ct_state &
+					  OVS_CS_F_NAT_MASK));
+	}
+
+	return ct;
+}
+
+/* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
+static bool skb_nfct_cached(struct net *net,
+			    const struct sw_flow_key *key,
+			    const struct ovs_conntrack_info *info,
+			    struct sk_buff *skb)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	bool ct_executed = true;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
+
+	if (ct)
+		nf_ct_get(skb, &ctinfo);
+	else
+		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;
+	}
+	if (info->nf_ct_timeout) {
+		struct nf_conn_timeout *timeout_ext;
+
+		timeout_ext = nf_ct_timeout_find(ct);
+		if (!timeout_ext || info->nf_ct_timeout !=
+		    rcu_dereference(timeout_ext->timeout))
+			return false;
+	}
+	/* Force conntrack entry direction to the current packet? */
+	if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
+		/* Delete the conntrack entry if confirmed, else just release
+		 * the reference.
+		 */
+		if (nf_ct_is_confirmed(ct))
+			nf_ct_delete(ct, 0, 0);
+
+		nf_ct_put(ct);
+		nf_ct_set(skb, NULL, 0);
+		return false;
+	}
+
+	return ct_executed;
+}
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+static void ovs_nat_update_key(struct sw_flow_key *key,
+			       const struct sk_buff *skb,
+			       enum nf_nat_manip_type maniptype)
+{
+	if (maniptype == NF_NAT_MANIP_SRC) {
+		__be16 src;
+
+		key->ct_state |= OVS_CS_F_SRC_NAT;
+		if (key->eth.type == htons(ETH_P_IP))
+			key->ipv4.addr.src = ip_hdr(skb)->saddr;
+		else if (key->eth.type == htons(ETH_P_IPV6))
+			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
+			       sizeof(key->ipv6.addr.src));
+		else
+			return;
+
+		if (key->ip.proto == IPPROTO_UDP)
+			src = udp_hdr(skb)->source;
+		else if (key->ip.proto == IPPROTO_TCP)
+			src = tcp_hdr(skb)->source;
+		else if (key->ip.proto == IPPROTO_SCTP)
+			src = sctp_hdr(skb)->source;
+		else
+			return;
+
+		key->tp.src = src;
+	} else {
+		__be16 dst;
+
+		key->ct_state |= OVS_CS_F_DST_NAT;
+		if (key->eth.type == htons(ETH_P_IP))
+			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
+		else if (key->eth.type == htons(ETH_P_IPV6))
+			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
+			       sizeof(key->ipv6.addr.dst));
+		else
+			return;
+
+		if (key->ip.proto == IPPROTO_UDP)
+			dst = udp_hdr(skb)->dest;
+		else if (key->ip.proto == IPPROTO_TCP)
+			dst = tcp_hdr(skb)->dest;
+		else if (key->ip.proto == IPPROTO_SCTP)
+			dst = sctp_hdr(skb)->dest;
+		else
+			return;
+
+		key->tp.dst = dst;
+	}
+}
+
+/* Modelled after nf_nat_ipv[46]_fn().
+ * range is only used for new, uninitialized NAT state.
+ * Returns either NF_ACCEPT or NF_DROP.
+ */
+static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
+			      enum ip_conntrack_info ctinfo,
+			      const struct nf_nat_range2 *range,
+			      enum nf_nat_manip_type maniptype, struct sw_flow_key *key)
+{
+	int hooknum, nh_off, err = NF_ACCEPT;
+
+	nh_off = skb_network_offset(skb);
+	skb_pull_rcsum(skb, nh_off);
+
+	/* See HOOK2MANIP(). */
+	if (maniptype == NF_NAT_MANIP_SRC)
+		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
+	else
+		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
+
+	switch (ctinfo) {
+	case IP_CT_RELATED:
+	case IP_CT_RELATED_REPLY:
+		if (IS_ENABLED(CONFIG_NF_NAT) &&
+		    skb->protocol == htons(ETH_P_IP) &&
+		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
+			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
+							   hooknum))
+				err = NF_DROP;
+			goto push;
+		} else if (IS_ENABLED(CONFIG_IPV6) &&
+			   skb->protocol == htons(ETH_P_IPV6)) {
+			__be16 frag_off;
+			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
+			int hdrlen = ipv6_skip_exthdr(skb,
+						      sizeof(struct ipv6hdr),
+						      &nexthdr, &frag_off);
+
+			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
+				if (!nf_nat_icmpv6_reply_translation(skb, ct,
+								     ctinfo,
+								     hooknum,
+								     hdrlen))
+					err = NF_DROP;
+				goto push;
+			}
+		}
+		/* Non-ICMP, fall thru to initialize if needed. */
+		fallthrough;
+	case IP_CT_NEW:
+		/* Seen it before?  This can happen for loopback, retrans,
+		 * or local packets.
+		 */
+		if (!nf_nat_initialized(ct, maniptype)) {
+			/* Initialize according to the NAT action. */
+			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
+				/* Action is set up to establish a new
+				 * mapping.
+				 */
+				? nf_nat_setup_info(ct, range, maniptype)
+				: nf_nat_alloc_null_binding(ct, hooknum);
+			if (err != NF_ACCEPT)
+				goto push;
+		}
+		break;
+
+	case IP_CT_ESTABLISHED:
+	case IP_CT_ESTABLISHED_REPLY:
+		break;
+
+	default:
+		err = NF_DROP;
+		goto push;
+	}
+
+	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
+push:
+	skb_push_rcsum(skb, nh_off);
+
+	/* Update the flow key if NAT successful. */
+	if (err == NF_ACCEPT)
+		ovs_nat_update_key(key, skb, maniptype);
+
+	return err;
+}
+
+/* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
+static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
+		      const struct ovs_conntrack_info *info,
+		      struct sk_buff *skb, struct nf_conn *ct,
+		      enum ip_conntrack_info ctinfo)
+{
+	enum nf_nat_manip_type maniptype;
+	int err;
+
+	/* Add NAT extension if not confirmed yet. */
+	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
+		return NF_ACCEPT;   /* Can't NAT. */
+
+	/* Determine NAT type.
+	 * Check if the NAT type can be deduced from the tracked connection.
+	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
+	 * when committing.
+	 */
+	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
+	    ct->status & IPS_NAT_MASK &&
+	    (ctinfo != IP_CT_RELATED || info->commit)) {
+		/* NAT an established or related connection like before. */
+		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
+			/* This is the REPLY direction for a connection
+			 * for which NAT was applied in the forward
+			 * direction.  Do the reverse NAT.
+			 */
+			maniptype = ct->status & IPS_SRC_NAT
+				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
+		else
+			maniptype = ct->status & IPS_SRC_NAT
+				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
+	} else if (info->nat & OVS_CT_SRC_NAT) {
+		maniptype = NF_NAT_MANIP_SRC;
+	} else if (info->nat & OVS_CT_DST_NAT) {
+		maniptype = NF_NAT_MANIP_DST;
+	} else {
+		return NF_ACCEPT; /* Connection is not NATed. */
+	}
+	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype, key);
+
+	if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) {
+		if (ct->status & IPS_SRC_NAT) {
+			if (maniptype == NF_NAT_MANIP_SRC)
+				maniptype = NF_NAT_MANIP_DST;
+			else
+				maniptype = NF_NAT_MANIP_SRC;
+
+			err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
+						 maniptype, key);
+		} else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) {
+			err = ovs_ct_nat_execute(skb, ct, ctinfo, NULL,
+						 NF_NAT_MANIP_SRC, key);
+		}
+	}
+
+	return err;
+}
+#else /* !CONFIG_NF_NAT */
+static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
+		      const struct ovs_conntrack_info *info,
+		      struct sk_buff *skb, struct nf_conn *ct,
+		      enum ip_conntrack_info ctinfo)
+{
+	return NF_ACCEPT;
+}
+#endif
+
+/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
+ * not done already.  Update key with new CT state after passing the packet
+ * through conntrack.
+ * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
+ * set to NULL and 0 will be returned.
+ */
+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.
+	 */
+	bool cached = skb_nfct_cached(net, key, info, skb);
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+
+	if (!cached) {
+		struct nf_hook_state state = {
+			.hook = NF_INET_PRE_ROUTING,
+			.pf = info->family,
+			.net = net,
+		};
+		struct nf_conn *tmpl = info->ct;
+		int err;
+
+		/* Associate skb with specified zone. */
+		if (tmpl) {
+			ct = nf_ct_get(skb, &ctinfo);
+			nf_ct_put(ct);
+			nf_conntrack_get(&tmpl->ct_general);
+			nf_ct_set(skb, tmpl, IP_CT_NEW);
+		}
+
+		err = nf_conntrack_in(skb, &state);
+		if (err != NF_ACCEPT)
+			return -ENOENT;
+
+		/* Clear CT state NAT flags to mark that we have not yet done
+		 * NAT after the nf_conntrack_in() call.  We can actually clear
+		 * the whole state, as it will be re-initialized below.
+		 */
+		key->ct_state = 0;
+
+		/* Update the key, but keep the NAT flags. */
+		ovs_ct_update_key(skb, info, key, true, true);
+	}
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct) {
+		bool add_helper = false;
+
+		/* Packets starting a new connection must be NATted before the
+		 * helper, so that the helper knows about the NAT.  We enforce
+		 * this by delaying both NAT and helper calls for unconfirmed
+		 * connections until the committing CT action.  For later
+		 * packets NAT and Helper may be called in either order.
+		 *
+		 * NAT will be done only if the CT action has NAT, and only
+		 * once per packet (per zone), as guarded by the NAT bits in
+		 * the key->ct_state.
+		 */
+		if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
+		    (nf_ct_is_confirmed(ct) || info->commit) &&
+		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
+			return -EINVAL;
+		}
+
+		/* Userspace may decide to perform a ct lookup without a helper
+		 * specified followed by a (recirculate and) commit with one,
+		 * or attach a helper in a later commit.  Therefore, for
+		 * connections which we will commit, we may need to attach
+		 * the helper here.
+		 */
+		if (!nf_ct_is_confirmed(ct) && info->commit &&
+		    info->helper && !nfct_help(ct)) {
+			int err = __nf_ct_try_assign_helper(ct, info->ct,
+							    GFP_ATOMIC);
+			if (err)
+				return err;
+			add_helper = true;
+
+			/* helper installed, add seqadj if NAT is required */
+			if (info->nat && !nfct_seqadj(ct)) {
+				if (!nfct_seqadj_ext_add(ct))
+					return -EINVAL;
+			}
+		}
+
+		/* Call the helper only if:
+		 * - nf_conntrack_in() was executed above ("!cached") or a
+		 *   helper was just attached ("add_helper") for a confirmed
+		 *   connection, or
+		 * - When committing an unconfirmed connection.
+		 */
+		if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
+					      info->commit) &&
+		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
+			return -EINVAL;
+		}
+
+		if (nf_ct_protonum(ct) == IPPROTO_TCP &&
+		    nf_ct_is_confirmed(ct) && nf_conntrack_tcp_established(ct)) {
+			/* Be liberal for tcp packets so that out-of-window
+			 * packets are not marked invalid.
+			 */
+			nf_ct_set_tcp_be_liberal(ct);
+		}
+
+		nf_conn_act_ct_ext_fill(skb, ct, ctinfo);
+	}
+
+	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;
+
+	/* If we pass an expected packet through nf_conntrack_in() the
+	 * expectation is typically removed, but the packet could still be
+	 * lost in upcall processing.  To prevent this from happening we
+	 * perform an explicit expectation lookup.  Expected connections are
+	 * always new, and will be passed through conntrack only when they are
+	 * committed, as it is OK to remove the expectation at that time.
+	 */
+	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
+	if (exp) {
+		u8 state;
+
+		/* NOTE: New connections are NATted and Helped only when
+		 * committed, so we are not calling into NAT here.
+		 */
+		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
+		__ovs_ct_update_key(key, state, &info->zone, exp->master);
+	} else {
+		struct nf_conn *ct;
+		int err;
+
+		err = __ovs_ct_lookup(net, key, info, skb);
+		if (err)
+			return err;
+
+		ct = (struct nf_conn *)skb_nfct(skb);
+		if (ct)
+			nf_ct_deliver_cached_events(ct);
+	}
+
+	return 0;
+}
+
+static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
+{
+	size_t i;
+
+	for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
+		if (labels->ct_labels_32[i])
+			return true;
+
+	return false;
+}
+
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+static struct hlist_head *ct_limit_hash_bucket(
+	const struct ovs_ct_limit_info *info, u16 zone)
+{
+	return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
+}
+
+/* Call with ovs_mutex */
+static void ct_limit_set(const struct ovs_ct_limit_info *info,
+			 struct ovs_ct_limit *new_ct_limit)
+{
+	struct ovs_ct_limit *ct_limit;
+	struct hlist_head *head;
+
+	head = ct_limit_hash_bucket(info, new_ct_limit->zone);
+	hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
+		if (ct_limit->zone == new_ct_limit->zone) {
+			hlist_replace_rcu(&ct_limit->hlist_node,
+					  &new_ct_limit->hlist_node);
+			kfree_rcu(ct_limit, rcu);
+			return;
+		}
+	}
+
+	hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
+}
+
+/* Call with ovs_mutex */
+static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
+{
+	struct ovs_ct_limit *ct_limit;
+	struct hlist_head *head;
+	struct hlist_node *n;
+
+	head = ct_limit_hash_bucket(info, zone);
+	hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
+		if (ct_limit->zone == zone) {
+			hlist_del_rcu(&ct_limit->hlist_node);
+			kfree_rcu(ct_limit, rcu);
+			return;
+		}
+	}
+}
+
+/* Call with RCU read lock */
+static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
+{
+	struct ovs_ct_limit *ct_limit;
+	struct hlist_head *head;
+
+	head = ct_limit_hash_bucket(info, zone);
+	hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
+		if (ct_limit->zone == zone)
+			return ct_limit->limit;
+	}
+
+	return info->default_limit;
+}
+
+static int ovs_ct_check_limit(struct net *net,
+			      const struct ovs_conntrack_info *info,
+			      const struct nf_conntrack_tuple *tuple)
+{
+	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
+	const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
+	u32 per_zone_limit, connections;
+	u32 conncount_key;
+
+	conncount_key = info->zone.id;
+
+	per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
+	if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
+		return 0;
+
+	connections = nf_conncount_count(net, ct_limit_info->data,
+					 &conncount_key, tuple, &info->zone);
+	if (connections > per_zone_limit)
+		return -ENOMEM;
+
+	return 0;
+}
+#endif
+
+/* 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)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	int err;
+
+	err = __ovs_ct_lookup(net, key, info, skb);
+	if (err)
+		return err;
+
+	/* The connection could be invalid, in which case this is a no-op.*/
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		return 0;
+
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+	if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
+		if (!nf_ct_is_confirmed(ct)) {
+			err = ovs_ct_check_limit(net, info,
+				&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+			if (err) {
+				net_warn_ratelimited("openvswitch: zone: %u "
+					"exceeds conntrack limit\n",
+					info->zone.id);
+				return err;
+			}
+		}
+	}
+#endif
+
+	/* Set the conntrack event mask if given.  NEW and DELETE events have
+	 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
+	 * typically would receive many kinds of updates.  Setting the event
+	 * mask allows those events to be filtered.  The set event mask will
+	 * remain in effect for the lifetime of the connection unless changed
+	 * by a further CT action with both the commit flag and the eventmask
+	 * option. */
+	if (info->have_eventmask) {
+		struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
+
+		if (cache)
+			cache->ctmask = info->eventmask;
+	}
+
+	/* Apply changes before confirming the connection so that the initial
+	 * conntrack NEW netlink event carries the values given in the CT
+	 * action.
+	 */
+	if (info->mark.mask) {
+		err = ovs_ct_set_mark(ct, key, info->mark.value,
+				      info->mark.mask);
+		if (err)
+			return err;
+	}
+	if (!nf_ct_is_confirmed(ct)) {
+		err = ovs_ct_init_labels(ct, key, &info->labels.value,
+					 &info->labels.mask);
+		if (err)
+			return err;
+
+		nf_conn_act_ct_ext_add(skb, ct, ctinfo);
+	} else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
+		   labels_nonzero(&info->labels.mask)) {
+		err = ovs_ct_set_labels(ct, key, &info->labels.value,
+					&info->labels.mask);
+		if (err)
+			return err;
+	}
+	/* This will take care of sending queued events even if the connection
+	 * is already confirmed.
+	 */
+	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* Trim the skb to the length specified by the IP/IPv6 header,
+ * removing any trailing lower-layer padding. This prepares the skb
+ * for higher-layer processing that assumes skb->len excludes padding
+ * (such as nf_ip_checksum). The caller needs to pull the skb to the
+ * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
+ */
+static int ovs_skb_network_trim(struct sk_buff *skb)
+{
+	unsigned int len;
+	int err;
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		len = ntohs(ip_hdr(skb)->tot_len);
+		break;
+	case htons(ETH_P_IPV6):
+		len = sizeof(struct ipv6hdr)
+			+ ntohs(ipv6_hdr(skb)->payload_len);
+		break;
+	default:
+		len = skb->len;
+	}
+
+	err = pskb_trim_rcsum(skb, len);
+	if (err)
+		kfree_skb(skb);
+
+	return err;
+}
+
+/* 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_rcsum(skb, nh_ofs);
+
+	err = ovs_skb_network_trim(skb);
+	if (err)
+		return err;
+
+	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);
+
+	skb_push_rcsum(skb, nh_ofs);
+	if (err)
+		kfree_skb(skb);
+	return err;
+}
+
+int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+
+	ct = nf_ct_get(skb, &ctinfo);
+
+	nf_ct_put(ct);
+	nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
+
+	if (key)
+		ovs_ct_fill_key(skb, key, false);
+
+	return 0;
+}
+
+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;
+	int ret = 0;
+
+	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, GFP_KERNEL);
+	if (!help) {
+		nf_conntrack_helper_put(helper);
+		return -ENOMEM;
+	}
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+	if (info->nat) {
+		ret = nf_nat_helper_try_module_get(name, info->family,
+						   key->ip.proto);
+		if (ret) {
+			nf_conntrack_helper_put(helper);
+			OVS_NLERR(log, "Failed to load \"%s\" NAT helper, error: %d",
+				  name, ret);
+			return ret;
+		}
+	}
+#endif
+	rcu_assign_pointer(help->helper, helper);
+	info->helper = helper;
+	return ret;
+}
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+static int parse_nat(const struct nlattr *attr,
+		     struct ovs_conntrack_info *info, bool log)
+{
+	struct nlattr *a;
+	int rem;
+	bool have_ip_max = false;
+	bool have_proto_max = false;
+	bool ip_vers = (info->family == NFPROTO_IPV6);
+
+	nla_for_each_nested(a, attr, rem) {
+		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
+			[OVS_NAT_ATTR_SRC] = {0, 0},
+			[OVS_NAT_ATTR_DST] = {0, 0},
+			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
+						 sizeof(struct in6_addr)},
+			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
+						 sizeof(struct in6_addr)},
+			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
+			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
+			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
+			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
+			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
+		};
+		int type = nla_type(a);
+
+		if (type > OVS_NAT_ATTR_MAX) {
+			OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
+				  type, OVS_NAT_ATTR_MAX);
+			return -EINVAL;
+		}
+
+		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
+			OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
+				  type, nla_len(a),
+				  ovs_nat_attr_lens[type][ip_vers]);
+			return -EINVAL;
+		}
+
+		switch (type) {
+		case OVS_NAT_ATTR_SRC:
+		case OVS_NAT_ATTR_DST:
+			if (info->nat) {
+				OVS_NLERR(log, "Only one type of NAT may be specified");
+				return -ERANGE;
+			}
+			info->nat |= OVS_CT_NAT;
+			info->nat |= ((type == OVS_NAT_ATTR_SRC)
+					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
+			break;
+
+		case OVS_NAT_ATTR_IP_MIN:
+			nla_memcpy(&info->range.min_addr, a,
+				   sizeof(info->range.min_addr));
+			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
+			break;
+
+		case OVS_NAT_ATTR_IP_MAX:
+			have_ip_max = true;
+			nla_memcpy(&info->range.max_addr, a,
+				   sizeof(info->range.max_addr));
+			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
+			break;
+
+		case OVS_NAT_ATTR_PROTO_MIN:
+			info->range.min_proto.all = htons(nla_get_u16(a));
+			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+			break;
+
+		case OVS_NAT_ATTR_PROTO_MAX:
+			have_proto_max = true;
+			info->range.max_proto.all = htons(nla_get_u16(a));
+			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+			break;
+
+		case OVS_NAT_ATTR_PERSISTENT:
+			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
+			break;
+
+		case OVS_NAT_ATTR_PROTO_HASH:
+			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
+			break;
+
+		case OVS_NAT_ATTR_PROTO_RANDOM:
+			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
+			break;
+
+		default:
+			OVS_NLERR(log, "Unknown nat attribute (%d)", type);
+			return -EINVAL;
+		}
+	}
+
+	if (rem > 0) {
+		OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
+		return -EINVAL;
+	}
+	if (!info->nat) {
+		/* Do not allow flags if no type is given. */
+		if (info->range.flags) {
+			OVS_NLERR(log,
+				  "NAT flags may be given only when NAT range (SRC or DST) is also specified."
+				  );
+			return -EINVAL;
+		}
+		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
+	} else if (!info->commit) {
+		OVS_NLERR(log,
+			  "NAT attributes may be specified only when CT COMMIT flag is also specified."
+			  );
+		return -EINVAL;
+	}
+	/* Allow missing IP_MAX. */
+	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
+		memcpy(&info->range.max_addr, &info->range.min_addr,
+		       sizeof(info->range.max_addr));
+	}
+	/* Allow missing PROTO_MAX. */
+	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
+	    !have_proto_max) {
+		info->range.max_proto.all = info->range.min_proto.all;
+	}
+	return 0;
+}
+#endif
+
+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_FORCE_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 },
+#if IS_ENABLED(CONFIG_NF_NAT)
+	/* NAT length is checked when parsing the nested attributes. */
+	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
+#endif
+	[OVS_CT_ATTR_EVENTMASK]	= { .minlen = sizeof(u32),
+				    .maxlen = sizeof(u32) },
+	[OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
+				  .maxlen = CTNL_TIMEOUT_NAME_MAX },
+};
+
+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;
+		int minlen;
+
+		if (type > OVS_CT_ATTR_MAX) {
+			OVS_NLERR(log,
+				  "Unknown conntrack attr (type=%d, max=%d)",
+				  type, OVS_CT_ATTR_MAX);
+			return -EINVAL;
+		}
+
+		maxlen = ovs_ct_attr_lens[type].maxlen;
+		minlen = ovs_ct_attr_lens[type].minlen;
+		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_FORCE_COMMIT:
+			info->force = true;
+			fallthrough;
+		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;
+#if IS_ENABLED(CONFIG_NF_NAT)
+		case OVS_CT_ATTR_NAT: {
+			int err = parse_nat(a, info, log);
+
+			if (err)
+				return err;
+			break;
+		}
+#endif
+		case OVS_CT_ATTR_EVENTMASK:
+			info->have_eventmask = true;
+			info->eventmask = nla_get_u32(a);
+			break;
+#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+		case OVS_CT_ATTR_TIMEOUT:
+			memcpy(info->timeout, nla_data(a), nla_len(a));
+			if (!memchr(info->timeout, '\0', nla_len(a))) {
+				OVS_NLERR(log, "Invalid conntrack timeout");
+				return -EINVAL;
+			}
+			break;
+#endif
+
+		default:
+			OVS_NLERR(log, "Unknown conntrack attr (%d)",
+				  type);
+			return -EINVAL;
+		}
+	}
+
+#ifdef CONFIG_NF_CONNTRACK_MARK
+	if (!info->commit && info->mark.mask) {
+		OVS_NLERR(log,
+			  "Setting conntrack mark requires 'commit' flag.");
+		return -EINVAL;
+	}
+#endif
+#ifdef CONFIG_NF_CONNTRACK_LABELS
+	if (!info->commit && labels_nonzero(&info->labels.mask)) {
+		OVS_NLERR(log,
+			  "Setting conntrack labels requires 'commit' flag.");
+		return -EINVAL;
+	}
+#endif
+	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;
+	}
+
+	if (ct_info.timeout[0]) {
+		if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
+				      ct_info.timeout))
+			pr_info_ratelimited("Failed to associated timeout "
+					    "policy `%s'\n", ct_info.timeout);
+		else
+			ct_info.nf_ct_timeout = rcu_dereference(
+				nf_ct_timeout_find(ct_info.ct)->timeout);
+
+	}
+
+	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;
+
+	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
+	return 0;
+err_free_ct:
+	__ovs_ct_free_action(&ct_info);
+	return err;
+}
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
+			       struct sk_buff *skb)
+{
+	struct nlattr *start;
+
+	start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
+	if (!start)
+		return false;
+
+	if (info->nat & OVS_CT_SRC_NAT) {
+		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
+			return false;
+	} else if (info->nat & OVS_CT_DST_NAT) {
+		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
+			return false;
+	} else {
+		goto out;
+	}
+
+	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
+		if (IS_ENABLED(CONFIG_NF_NAT) &&
+		    info->family == NFPROTO_IPV4) {
+			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
+					    info->range.min_addr.ip) ||
+			    (info->range.max_addr.ip
+			     != info->range.min_addr.ip &&
+			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
+					      info->range.max_addr.ip))))
+				return false;
+		} else if (IS_ENABLED(CONFIG_IPV6) &&
+			   info->family == NFPROTO_IPV6) {
+			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
+					     &info->range.min_addr.in6) ||
+			    (memcmp(&info->range.max_addr.in6,
+				    &info->range.min_addr.in6,
+				    sizeof(info->range.max_addr.in6)) &&
+			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
+					       &info->range.max_addr.in6))))
+				return false;
+		} else {
+			return false;
+		}
+	}
+	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
+	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
+			 ntohs(info->range.min_proto.all)) ||
+	     (info->range.max_proto.all != info->range.min_proto.all &&
+	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
+			  ntohs(info->range.max_proto.all)))))
+		return false;
+
+	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
+	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
+		return false;
+	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
+	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
+		return false;
+	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
+	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
+		return false;
+out:
+	nla_nest_end(skb, start);
+
+	return true;
+}
+#endif
+
+int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
+			  struct sk_buff *skb)
+{
+	struct nlattr *start;
+
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
+	if (!start)
+		return -EMSGSIZE;
+
+	if (ct_info->commit && nla_put_flag(skb, ct_info->force
+					    ? OVS_CT_ATTR_FORCE_COMMIT
+					    : 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;
+	}
+	if (ct_info->have_eventmask &&
+	    nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
+		return -EMSGSIZE;
+	if (ct_info->timeout[0]) {
+		if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
+			return -EMSGSIZE;
+	}
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
+		return -EMSGSIZE;
+#endif
+	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) {
+#if IS_ENABLED(CONFIG_NF_NAT)
+		if (ct_info->nat)
+			nf_nat_helper_put(ct_info->helper);
+#endif
+		nf_conntrack_helper_put(ct_info->helper);
+	}
+	if (ct_info->ct) {
+		if (ct_info->timeout[0])
+			nf_ct_destroy_timeout(ct_info->ct);
+		nf_ct_tmpl_free(ct_info->ct);
+	}
+}
+
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
+{
+	int i, err;
+
+	ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
+					 GFP_KERNEL);
+	if (!ovs_net->ct_limit_info)
+		return -ENOMEM;
+
+	ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
+	ovs_net->ct_limit_info->limits =
+		kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
+			      GFP_KERNEL);
+	if (!ovs_net->ct_limit_info->limits) {
+		kfree(ovs_net->ct_limit_info);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
+		INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
+
+	ovs_net->ct_limit_info->data =
+		nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
+
+	if (IS_ERR(ovs_net->ct_limit_info->data)) {
+		err = PTR_ERR(ovs_net->ct_limit_info->data);
+		kfree(ovs_net->ct_limit_info->limits);
+		kfree(ovs_net->ct_limit_info);
+		pr_err("openvswitch: failed to init nf_conncount %d\n", err);
+		return err;
+	}
+	return 0;
+}
+
+static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
+{
+	const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
+	int i;
+
+	nf_conncount_destroy(net, NFPROTO_INET, info->data);
+	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
+		struct hlist_head *head = &info->limits[i];
+		struct ovs_ct_limit *ct_limit;
+
+		hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
+					 lockdep_ovsl_is_held())
+			kfree_rcu(ct_limit, rcu);
+	}
+	kfree(info->limits);
+	kfree(info);
+}
+
+static struct sk_buff *
+ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
+			     struct ovs_header **ovs_reply_header)
+{
+	struct ovs_header *ovs_header = info->userhdr;
+	struct sk_buff *skb;
+
+	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return ERR_PTR(-ENOMEM);
+
+	*ovs_reply_header = genlmsg_put(skb, info->snd_portid,
+					info->snd_seq,
+					&dp_ct_limit_genl_family, 0, cmd);
+
+	if (!*ovs_reply_header) {
+		nlmsg_free(skb);
+		return ERR_PTR(-EMSGSIZE);
+	}
+	(*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
+
+	return skb;
+}
+
+static bool check_zone_id(int zone_id, u16 *pzone)
+{
+	if (zone_id >= 0 && zone_id <= 65535) {
+		*pzone = (u16)zone_id;
+		return true;
+	}
+	return false;
+}
+
+static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
+				       struct ovs_ct_limit_info *info)
+{
+	struct ovs_zone_limit *zone_limit;
+	int rem;
+	u16 zone;
+
+	rem = NLA_ALIGN(nla_len(nla_zone_limit));
+	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
+
+	while (rem >= sizeof(*zone_limit)) {
+		if (unlikely(zone_limit->zone_id ==
+				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
+			ovs_lock();
+			info->default_limit = zone_limit->limit;
+			ovs_unlock();
+		} else if (unlikely(!check_zone_id(
+				zone_limit->zone_id, &zone))) {
+			OVS_NLERR(true, "zone id is out of range");
+		} else {
+			struct ovs_ct_limit *ct_limit;
+
+			ct_limit = kmalloc(sizeof(*ct_limit),
+					   GFP_KERNEL_ACCOUNT);
+			if (!ct_limit)
+				return -ENOMEM;
+
+			ct_limit->zone = zone;
+			ct_limit->limit = zone_limit->limit;
+
+			ovs_lock();
+			ct_limit_set(info, ct_limit);
+			ovs_unlock();
+		}
+		rem -= NLA_ALIGN(sizeof(*zone_limit));
+		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
+				NLA_ALIGN(sizeof(*zone_limit)));
+	}
+
+	if (rem)
+		OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
+
+	return 0;
+}
+
+static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
+				       struct ovs_ct_limit_info *info)
+{
+	struct ovs_zone_limit *zone_limit;
+	int rem;
+	u16 zone;
+
+	rem = NLA_ALIGN(nla_len(nla_zone_limit));
+	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
+
+	while (rem >= sizeof(*zone_limit)) {
+		if (unlikely(zone_limit->zone_id ==
+				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
+			ovs_lock();
+			info->default_limit = OVS_CT_LIMIT_DEFAULT;
+			ovs_unlock();
+		} else if (unlikely(!check_zone_id(
+				zone_limit->zone_id, &zone))) {
+			OVS_NLERR(true, "zone id is out of range");
+		} else {
+			ovs_lock();
+			ct_limit_del(info, zone);
+			ovs_unlock();
+		}
+		rem -= NLA_ALIGN(sizeof(*zone_limit));
+		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
+				NLA_ALIGN(sizeof(*zone_limit)));
+	}
+
+	if (rem)
+		OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
+
+	return 0;
+}
+
+static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
+					  struct sk_buff *reply)
+{
+	struct ovs_zone_limit zone_limit = {
+		.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE,
+		.limit   = info->default_limit,
+	};
+
+	return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
+}
+
+static int __ovs_ct_limit_get_zone_limit(struct net *net,
+					 struct nf_conncount_data *data,
+					 u16 zone_id, u32 limit,
+					 struct sk_buff *reply)
+{
+	struct nf_conntrack_zone ct_zone;
+	struct ovs_zone_limit zone_limit;
+	u32 conncount_key = zone_id;
+
+	zone_limit.zone_id = zone_id;
+	zone_limit.limit = limit;
+	nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
+
+	zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
+					      &ct_zone);
+	return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
+}
+
+static int ovs_ct_limit_get_zone_limit(struct net *net,
+				       struct nlattr *nla_zone_limit,
+				       struct ovs_ct_limit_info *info,
+				       struct sk_buff *reply)
+{
+	struct ovs_zone_limit *zone_limit;
+	int rem, err;
+	u32 limit;
+	u16 zone;
+
+	rem = NLA_ALIGN(nla_len(nla_zone_limit));
+	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
+
+	while (rem >= sizeof(*zone_limit)) {
+		if (unlikely(zone_limit->zone_id ==
+				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
+			err = ovs_ct_limit_get_default_limit(info, reply);
+			if (err)
+				return err;
+		} else if (unlikely(!check_zone_id(zone_limit->zone_id,
+							&zone))) {
+			OVS_NLERR(true, "zone id is out of range");
+		} else {
+			rcu_read_lock();
+			limit = ct_limit_get(info, zone);
+			rcu_read_unlock();
+
+			err = __ovs_ct_limit_get_zone_limit(
+				net, info->data, zone, limit, reply);
+			if (err)
+				return err;
+		}
+		rem -= NLA_ALIGN(sizeof(*zone_limit));
+		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
+				NLA_ALIGN(sizeof(*zone_limit)));
+	}
+
+	if (rem)
+		OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
+
+	return 0;
+}
+
+static int ovs_ct_limit_get_all_zone_limit(struct net *net,
+					   struct ovs_ct_limit_info *info,
+					   struct sk_buff *reply)
+{
+	struct ovs_ct_limit *ct_limit;
+	struct hlist_head *head;
+	int i, err = 0;
+
+	err = ovs_ct_limit_get_default_limit(info, reply);
+	if (err)
+		return err;
+
+	rcu_read_lock();
+	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
+		head = &info->limits[i];
+		hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
+			err = __ovs_ct_limit_get_zone_limit(net, info->data,
+				ct_limit->zone, ct_limit->limit, reply);
+			if (err)
+				goto exit_err;
+		}
+	}
+
+exit_err:
+	rcu_read_unlock();
+	return err;
+}
+
+static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	struct sk_buff *reply;
+	struct ovs_header *ovs_reply_header;
+	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
+	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
+	int err;
+
+	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
+					     &ovs_reply_header);
+	if (IS_ERR(reply))
+		return PTR_ERR(reply);
+
+	if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
+		err = -EINVAL;
+		goto exit_err;
+	}
+
+	err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
+					  ct_limit_info);
+	if (err)
+		goto exit_err;
+
+	static_branch_enable(&ovs_ct_limit_enabled);
+
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+exit_err:
+	nlmsg_free(reply);
+	return err;
+}
+
+static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	struct sk_buff *reply;
+	struct ovs_header *ovs_reply_header;
+	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
+	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
+	int err;
+
+	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
+					     &ovs_reply_header);
+	if (IS_ERR(reply))
+		return PTR_ERR(reply);
+
+	if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
+		err = -EINVAL;
+		goto exit_err;
+	}
+
+	err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
+					  ct_limit_info);
+	if (err)
+		goto exit_err;
+
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+exit_err:
+	nlmsg_free(reply);
+	return err;
+}
+
+static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	struct nlattr *nla_reply;
+	struct sk_buff *reply;
+	struct ovs_header *ovs_reply_header;
+	struct net *net = sock_net(skb->sk);
+	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
+	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
+	int err;
+
+	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
+					     &ovs_reply_header);
+	if (IS_ERR(reply))
+		return PTR_ERR(reply);
+
+	nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
+	if (!nla_reply) {
+		err = -EMSGSIZE;
+		goto exit_err;
+	}
+
+	if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
+		err = ovs_ct_limit_get_zone_limit(
+			net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
+			reply);
+		if (err)
+			goto exit_err;
+	} else {
+		err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
+						      reply);
+		if (err)
+			goto exit_err;
+	}
+
+	nla_nest_end(reply, nla_reply);
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+exit_err:
+	nlmsg_free(reply);
+	return err;
+}
+
+static const struct genl_small_ops ct_limit_genl_ops[] = {
+	{ .cmd = OVS_CT_LIMIT_CMD_SET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
+					       * privilege.
+					       */
+		.doit = ovs_ct_limit_cmd_set,
+	},
+	{ .cmd = OVS_CT_LIMIT_CMD_DEL,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
+					       * privilege.
+					       */
+		.doit = ovs_ct_limit_cmd_del,
+	},
+	{ .cmd = OVS_CT_LIMIT_CMD_GET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = 0,		  /* OK for unprivileged users. */
+		.doit = ovs_ct_limit_cmd_get,
+	},
+};
+
+static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
+	.name = OVS_CT_LIMIT_MCGROUP,
+};
+
+struct genl_family dp_ct_limit_genl_family __ro_after_init = {
+	.hdrsize = sizeof(struct ovs_header),
+	.name = OVS_CT_LIMIT_FAMILY,
+	.version = OVS_CT_LIMIT_VERSION,
+	.maxattr = OVS_CT_LIMIT_ATTR_MAX,
+	.policy = ct_limit_policy,
+	.netnsok = true,
+	.parallel_ops = true,
+	.small_ops = ct_limit_genl_ops,
+	.n_small_ops = ARRAY_SIZE(ct_limit_genl_ops),
+	.resv_start_op = OVS_CT_LIMIT_CMD_GET + 1,
+	.mcgrps = &ovs_ct_limit_multicast_group,
+	.n_mcgrps = 1,
+	.module = THIS_MODULE,
+};
+#endif
+
+int 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 - 1)) {
+		ovs_net->xt_label = false;
+		OVS_NLERR(true, "Failed to set connlabel length");
+	} else {
+		ovs_net->xt_label = true;
+	}
+
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+	return ovs_ct_limit_init(net, ovs_net);
+#else
+	return 0;
+#endif
+}
+
+void ovs_ct_exit(struct net *net)
+{
+	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
+
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+	ovs_ct_limit_exit(net, ovs_net);
+#endif
+
+	if (ovs_net->xt_label)
+		nf_connlabels_put(net);
+}