diff --git a/include/net/tc_act/tc_conntrack.h b/include/net/tc_act/tc_conntrack.h
new file mode 100644
index 000000000000..45319e557f90
--- /dev/null
+++ b/include/net/tc_act/tc_conntrack.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_TC_CONNTRACK_H
+#define __NET_TC_CONNTRACK_H
+
+#include <net/act_api.h>
+
+struct tcf_conntrack_info {
+	struct tc_action common;
+	struct net *net;
+	u32 mask;
+	u32 statemask;
+	u16 zone;
+	u8 mode;
+	u8 maskshift;
+};
+
+#define to_conntrack(a) ((struct tcf_conntrack_info *)a)
+
+#endif /* __NET_TC_CONNTRACK_H */
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index 51a0496f78ea..a5a6930084d7 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -105,6 +105,7 @@ enum tca_id {
 	TCA_ID_IFE = TCA_ACT_IFE,
 	TCA_ID_SAMPLE = TCA_ACT_SAMPLE,
 	/* other actions go here */
+	TCA_ID_CONNTRACK,
 	__TCA_ID_MAX = 255
 };
 
diff --git a/include/uapi/linux/tc_act/tc_conntrack.h b/include/uapi/linux/tc_act/tc_conntrack.h
new file mode 100644
index 000000000000..99c4bfb29c21
--- /dev/null
+++ b/include/uapi/linux/tc_act/tc_conntrack.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __UAPI_TC_CONNTRACK_H
+#define __UAPI_TC_CONNTRACK_H
+
+#include <linux/types.h>
+#include <linux/pkt_cls.h>
+
+struct tc_conntrack {
+	tc_gen;
+	__u32 mask;
+	__u32 statemask;
+	__u16 zone;
+	__u8 mode;
+	__u8 maskshift;
+};
+
+enum {
+	TCA_CONNTRACK_UNSPEC,
+	TCA_CONNTRACK_PARMS,
+	TCA_CONNTRACK_TM,
+	TCA_CONNTRACK_PAD,
+	__TCA_CONNTRACK_MAX
+};
+#define TCA_CONNTRACK_MAX (__TCA_CONNTRACK_MAX - 1)
+
+enum {
+	CONNTRACK_FLAG_SETDSCP	= BIT(0)
+};
+
+#endif
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 5c02ad97ef23..848dc1dd3be1 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -876,6 +876,19 @@ config NET_ACT_CONNMARK
 	  To compile this code as a module, choose M here: the
 	  module will be called act_connmark.
 
+config NET_ACT_CONNTRACK
+        tristate "Netfilter Connmark to DSCP Retriever"
+        depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES
+        depends on NF_CONNTRACK && NF_CONNTRACK_MARK
+        help
+	  Say Y here to allow transfer of a connmark stored DSCP into
+	  ipv4/v6 diffserv
+
+	  If unsure, say N.
+
+	  To compile this code as a module, choose M here: the
+	  module will be called act_conntrack.
+
 config NET_ACT_SKBMOD
         tristate "skb data modification action"
         depends on NET_CLS_ACT
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 8a40431d7b5c..e962dd782046 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_NET_ACT_CSUM)	+= act_csum.o
 obj-$(CONFIG_NET_ACT_VLAN)	+= act_vlan.o
 obj-$(CONFIG_NET_ACT_BPF)	+= act_bpf.o
 obj-$(CONFIG_NET_ACT_CONNMARK)	+= act_connmark.o
+obj-$(CONFIG_NET_ACT_CONNTRACK)	+= act_conntrack.o
 obj-$(CONFIG_NET_ACT_SKBMOD)	+= act_skbmod.o
 obj-$(CONFIG_NET_ACT_IFE)	+= act_ife.o
 obj-$(CONFIG_NET_IFE_SKBMARK)	+= act_meta_mark.o
diff --git a/net/sched/act_conntrack.c b/net/sched/act_conntrack.c
new file mode 100644
index 000000000000..c08ff06aae60
--- /dev/null
+++ b/net/sched/act_conntrack.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+/* net/sched/act_conntrack.c  netfilter conntrack connmark->DSCP action
+ *
+ * Copyright (c) 2019 Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/pkt_cls.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/act_api.h>
+#include <net/pkt_cls.h>
+#include <uapi/linux/tc_act/tc_conntrack.h>
+#include <net/tc_act/tc_conntrack.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+
+static unsigned int conntrack_net_id;
+static struct tc_action_ops act_conntrack_ops;
+
+static void tcf_conntrack_set(struct nf_conn *ct, struct tcf_conntrack_info *ca,
+			      struct sk_buff *skb, int proto)
+{
+	u8 newdscp;
+
+	newdscp = (((ct->mark & ca->mask) >> ca->maskshift) << 2) &
+		     ~INET_ECN_MASK;
+
+	/* mark contains DSCP so restore DSCP bits from c->mark into diffserv */
+	/* using overlimits stats to count how many DSCP updates */
+	switch (proto) {
+	case NFPROTO_IPV4:
+		if ((ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK) !=
+		     newdscp) {
+			ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK,
+					    newdscp);
+			ca->tcf_qstats.overlimits++;
+		}
+		break;
+	case NFPROTO_IPV6:
+		if ((ipv6_get_dsfield(ipv6_hdr(skb)) &
+		     ~INET_ECN_MASK) != newdscp) {
+			ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK,
+					    newdscp);
+			ca->tcf_qstats.overlimits++;
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+static int tcf_conntrack_act(struct sk_buff *skb, const struct tc_action *a,
+			     struct tcf_result *res)
+{
+	const struct nf_conntrack_tuple_hash *thash = NULL;
+	struct nf_conntrack_tuple tuple;
+	enum ip_conntrack_info ctinfo;
+	struct tcf_conntrack_info *ca = to_conntrack(a);
+	struct nf_conntrack_zone zone;
+	struct nf_conn *ct;
+	int proto;
+
+	spin_lock(&ca->tcf_lock);
+	tcf_lastuse_update(&ca->tcf_tm);
+	bstats_update(&ca->tcf_bstats, skb);
+
+	if (unlikely(!(ca->mode & CONNTRACK_FLAG_SETDSCP)))
+		goto out;
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		if (skb->len < sizeof(struct iphdr))
+			goto out;
+
+		proto = NFPROTO_IPV4;
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		if (skb->len < sizeof(struct ipv6hdr))
+			goto out;
+
+		proto = NFPROTO_IPV6;
+	} else {
+		goto out;
+	}
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct) { /* look harder */
+		if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
+				       proto, ca->net, &tuple))
+			goto out;
+		zone.id = ca->zone;
+		zone.dir = NF_CT_DEFAULT_ZONE_DIR;
+
+		thash = nf_conntrack_find_get(ca->net, &zone, &tuple);
+		if (!thash)
+			goto out;
+
+		if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
+				       proto, ca->net, &tuple))
+			goto out;
+
+		ct = nf_ct_tuplehash_to_ctrack(thash);
+	}
+
+	if (!ca->statemask || (ct->mark & ca->statemask))
+		tcf_conntrack_set(ct, ca, skb, proto);
+
+	if (thash)
+		nf_ct_put(ct);
+
+out:
+	spin_unlock(&ca->tcf_lock);
+	return ca->tcf_action;
+}
+
+static const struct nla_policy conntrack_policy[TCA_CONNTRACK_MAX + 1] = {
+	[TCA_CONNTRACK_PARMS] = { .len = sizeof(struct tc_conntrack) },
+};
+
+static void conntrack_parmset(struct tcf_conntrack_info *ci,
+			      struct tc_conntrack *parm)
+{
+	ci->zone = parm->zone;
+	ci->mask = parm->mask;
+	ci->maskshift = ci->mask ? __ffs(ci->mask) : 0;
+	ci->statemask = parm->statemask;
+	ci->mode = parm->mode;
+
+	/* let's not trust userspace entirely */
+	/* need at least contiguous 6 bit mask */
+	if ((0x3f & (ci->mask >> ci->maskshift)) != 0x3f)
+		ci->mode &= ~CONNTRACK_FLAG_SETDSCP;
+	/* mask & statemask must not overlap */
+	if (ci->mask & ci->statemask)
+		ci->mode &= ~CONNTRACK_FLAG_SETDSCP;
+}
+
+static int tcf_conntrack_init(struct net *net, struct nlattr *nla,
+			      struct nlattr *est, struct tc_action **a,
+			      int ovr, int bind, bool rtnl_held,
+			      struct tcf_proto *tp,
+			      struct netlink_ext_ack *extack)
+{
+	struct tc_action_net *tn = net_generic(net, conntrack_net_id);
+	struct nlattr *tb[TCA_CONNTRACK_MAX + 1];
+	struct tcf_chain *goto_ch = NULL;
+	struct tcf_conntrack_info *ci;
+	struct tc_conntrack *parm;
+	int ret = 0, err;
+
+	if (!nla)
+		return -EINVAL;
+
+	ret = nla_parse_nested(tb, TCA_CONNTRACK_MAX, nla, conntrack_policy,
+			       NULL);
+	if (ret < 0)
+		return ret;
+
+	if (!tb[TCA_CONNTRACK_PARMS])
+		return -EINVAL;
+
+	parm = nla_data(tb[TCA_CONNTRACK_PARMS]);
+
+	ret = tcf_idr_check_alloc(tn, &parm->index, a, bind);
+	if (!ret) {
+		ret = tcf_idr_create(tn, parm->index, est, a,
+				     &act_conntrack_ops, bind, false);
+		if (ret) {
+			tcf_idr_cleanup(tn, parm->index);
+			return ret;
+		}
+
+		ci = to_conntrack(*a);
+		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
+					       extack);
+		if (err < 0)
+			goto release_idr;
+		tcf_action_set_ctrlact(*a, parm->action, goto_ch);
+		ci->net = net;
+		conntrack_parmset(ci, parm);
+
+		tcf_idr_insert(tn, *a);
+		ret = ACT_P_CREATED;
+	} else if (ret > 0) {
+		ci = to_conntrack(*a);
+		if (bind)
+			return 0;
+		if (!ovr) {
+			tcf_idr_release(*a, bind);
+			return -EEXIST;
+		}
+		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
+					       extack);
+		if (err < 0)
+			goto release_idr;
+		/* replacing action and zone */
+		spin_lock_bh(&ci->tcf_lock);
+		goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
+		conntrack_parmset(ci, parm);
+		spin_unlock_bh(&ci->tcf_lock);
+		if (goto_ch)
+			tcf_chain_put_by_act(goto_ch);
+		ret = 0;
+	}
+
+	return ret;
+release_idr:
+	tcf_idr_release(*a, bind);
+	return err;
+}
+
+static inline int tcf_conntrack_dump(struct sk_buff *skb, struct tc_action *a,
+				     int bind, int ref)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_conntrack_info *ci = to_conntrack(a);
+	struct tc_conntrack opt = {
+		.index   = ci->tcf_index,
+		.refcnt  = refcount_read(&ci->tcf_refcnt) - ref,
+		.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
+	};
+	struct tcf_t t;
+
+	spin_lock_bh(&ci->tcf_lock);
+	opt.action = ci->tcf_action;
+	opt.zone = ci->zone;
+	opt.mask = ci->mask;
+	opt.statemask = ci->statemask;
+	opt.mode = ci->mode;
+
+	if (nla_put(skb, TCA_CONNTRACK_PARMS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	tcf_tm_dump(&t, &ci->tcf_tm);
+	if (nla_put_64bit(skb, TCA_CONNTRACK_TM, sizeof(t), &t,
+			  TCA_CONNTRACK_PAD))
+		goto nla_put_failure;
+	spin_unlock_bh(&ci->tcf_lock);
+
+	return skb->len;
+
+nla_put_failure:
+	spin_unlock_bh(&ci->tcf_lock);
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int tcf_conntrack_walker(struct net *net, struct sk_buff *skb,
+				struct netlink_callback *cb, int type,
+				const struct tc_action_ops *ops,
+				struct netlink_ext_ack *extack)
+{
+	struct tc_action_net *tn = net_generic(net, conntrack_net_id);
+
+	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
+}
+
+static int tcf_conntrack_search(struct net *net, struct tc_action **a,
+				u32 index)
+{
+	struct tc_action_net *tn = net_generic(net, conntrack_net_id);
+
+	return tcf_idr_search(tn, a, index);
+}
+
+static struct tc_action_ops act_conntrack_ops = {
+	.kind		=	"conntrack",
+	.id		=	TCA_ID_CONNTRACK,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_conntrack_act,
+	.dump		=	tcf_conntrack_dump,
+	.init		=	tcf_conntrack_init,
+	.walk		=	tcf_conntrack_walker,
+	.lookup		=	tcf_conntrack_search,
+	.size		=	sizeof(struct tcf_conntrack_info),
+};
+
+static __net_init int conntrack_init_net(struct net *net)
+{
+	struct tc_action_net *tn = net_generic(net, conntrack_net_id);
+
+	return tc_action_net_init(tn, &act_conntrack_ops);
+}
+
+static void __net_exit conntrack_exit_net(struct list_head *net_list)
+{
+	tc_action_net_exit(net_list, conntrack_net_id);
+}
+
+static struct pernet_operations conntrack_net_ops = {
+	.init = conntrack_init_net,
+	.exit_batch = conntrack_exit_net,
+	.id   = &conntrack_net_id,
+	.size = sizeof(struct tc_action_net),
+};
+
+static int __init conntrack_init_module(void)
+{
+	return tcf_register_action(&act_conntrack_ops, &conntrack_net_ops);
+}
+
+static void __exit conntrack_cleanup_module(void)
+{
+	tcf_unregister_action(&act_conntrack_ops, &conntrack_net_ops);
+}
+
+module_init(conntrack_init_module);
+module_exit(conntrack_cleanup_module);
+MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>");
+MODULE_DESCRIPTION("Conntrack mark to DSCP restoring");
+MODULE_LICENSE("GPL");
diff --git a/tools/testing/selftests/tc-testing/config b/tools/testing/selftests/tc-testing/config
index 203302065458..104256b4fa2a 100644
--- a/tools/testing/selftests/tc-testing/config
+++ b/tools/testing/selftests/tc-testing/config
@@ -38,6 +38,7 @@ CONFIG_NET_ACT_CSUM=m
 CONFIG_NET_ACT_VLAN=m
 CONFIG_NET_ACT_BPF=m
 CONFIG_NET_ACT_CONNMARK=m
+CONFIG_NET_ACT_CONNTRACK=m
 CONFIG_NET_ACT_SKBMOD=m
 CONFIG_NET_ACT_IFE=m
 CONFIG_NET_ACT_TUNNEL_KEY=m
