Adding upstream version 6.6.15.upstream/6.6.15

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

15 files changed, 3470 insertions, 0 deletions

diff --git a/net/hsr/Kconfig b/net/hsr/Kconfig
new file mode 100644
index 000000000..1b048c17b
--- /dev/null
+++ b/net/hsr/Kconfig
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# IEC 62439-3 High-availability Seamless Redundancy
+#
+
+config HSR
+	tristate "High-availability Seamless Redundancy (HSR & PRP)"
+	help
+	  This enables IEC 62439 defined High-availability Seamless
+	  Redundancy (HSR) and Parallel Redundancy Protocol (PRP).
+
+	  If you say Y here, then your Linux box will be able to act as a
+	  DANH ("Doubly attached node implementing HSR") or DANP ("Doubly
+	  attached node implementing PRP"). For this to work, your Linux box
+	  needs (at least) two physical Ethernet interfaces.
+
+	  For DANH, it must be connected as a node in a ring network together
+	  with other HSR capable nodes. All Ethernet frames sent over the HSR
+	  device will be sent in both directions on the ring (over both slave
+	  ports), giving a redundant, instant fail-over network. Each HSR node
+	  in the ring acts like a bridge for HSR frames, but filters frames
+	  that have been forwarded earlier.
+
+	  For DANP, it must be connected as a node connecting to two
+	  separate networks over the two slave interfaces. Like HSR, Ethernet
+	  frames sent over the PRP device will be sent to both networks giving
+	  a redundant, instant fail-over network. Unlike HSR, PRP networks
+	  can have Singly Attached Nodes (SAN) such as PC, printer, bridges
+	  etc and will be able to communicate with DANP nodes.
+
+	  This code is a "best effort" to comply with the HSR standard as
+	  described in IEC 62439-3:2010 (HSRv0) and IEC 62439-3:2012 (HSRv1),
+	  and PRP standard described in IEC 62439-4:2012 (PRP), but no
+	  compliancy tests have been made. Use iproute2 to select the protocol
+	  you would like to use.
+
+	  You need to perform any and all necessary tests yourself before
+	  relying on this code in a safety critical system!
+
+	  If unsure, say N.
diff --git a/net/hsr/Makefile b/net/hsr/Makefile
new file mode 100644
index 000000000..75df90d3b
--- /dev/null
+++ b/net/hsr/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for HSR
+#
+
+obj-$(CONFIG_HSR)	+= hsr.o
+
+hsr-y			:= hsr_main.o hsr_framereg.o hsr_device.o \
+			   hsr_netlink.o hsr_slave.o hsr_forward.o
+hsr-$(CONFIG_DEBUG_FS) += hsr_debugfs.o
diff --git a/net/hsr/hsr_debugfs.c b/net/hsr/hsr_debugfs.c
new file mode 100644
index 000000000..1a195efc7
--- /dev/null
+++ b/net/hsr/hsr_debugfs.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * debugfs code for HSR & PRP
+ * Copyright (C) 2019 Texas Instruments Incorporated
+ *
+ * Author(s):
+ *	Murali Karicheri <m-karicheri2@ti.com>
+ */
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/debugfs.h>
+#include "hsr_main.h"
+#include "hsr_framereg.h"
+
+static struct dentry *hsr_debugfs_root_dir;
+
+/* hsr_node_table_show - Formats and prints node_table entries */
+static int
+hsr_node_table_show(struct seq_file *sfp, void *data)
+{
+	struct hsr_priv *priv = (struct hsr_priv *)sfp->private;
+	struct hsr_node *node;
+
+	seq_printf(sfp, "Node Table entries for (%s) device\n",
+		   (priv->prot_version == PRP_V1 ? "PRP" : "HSR"));
+	seq_puts(sfp, "MAC-Address-A,    MAC-Address-B,    time_in[A], ");
+	seq_puts(sfp, "time_in[B], Address-B port, ");
+	if (priv->prot_version == PRP_V1)
+		seq_puts(sfp, "SAN-A, SAN-B, DAN-P\n");
+	else
+		seq_puts(sfp, "DAN-H\n");
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(node, &priv->node_db, mac_list) {
+		/* skip self node */
+		if (hsr_addr_is_self(priv, node->macaddress_A))
+			continue;
+		seq_printf(sfp, "%pM ", &node->macaddress_A[0]);
+		seq_printf(sfp, "%pM ", &node->macaddress_B[0]);
+		seq_printf(sfp, "%10lx, ", node->time_in[HSR_PT_SLAVE_A]);
+		seq_printf(sfp, "%10lx, ", node->time_in[HSR_PT_SLAVE_B]);
+		seq_printf(sfp, "%14x, ", node->addr_B_port);
+
+		if (priv->prot_version == PRP_V1)
+			seq_printf(sfp, "%5x, %5x, %5x\n",
+				   node->san_a, node->san_b,
+				   (node->san_a == 0 && node->san_b == 0));
+		else
+			seq_printf(sfp, "%5x\n", 1);
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(hsr_node_table);
+
+void hsr_debugfs_rename(struct net_device *dev)
+{
+	struct hsr_priv *priv = netdev_priv(dev);
+	struct dentry *d;
+
+	d = debugfs_rename(hsr_debugfs_root_dir, priv->node_tbl_root,
+			   hsr_debugfs_root_dir, dev->name);
+	if (IS_ERR(d))
+		netdev_warn(dev, "failed to rename\n");
+	else
+		priv->node_tbl_root = d;
+}
+
+/* hsr_debugfs_init - create hsr node_table file for dumping
+ * the node table
+ *
+ * Description:
+ * When debugfs is configured this routine sets up the node_table file per
+ * hsr device for dumping the node_table entries
+ */
+void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev)
+{
+	struct dentry *de = NULL;
+
+	de = debugfs_create_dir(hsr_dev->name, hsr_debugfs_root_dir);
+	if (IS_ERR(de)) {
+		pr_err("Cannot create hsr debugfs directory\n");
+		return;
+	}
+
+	priv->node_tbl_root = de;
+
+	de = debugfs_create_file("node_table", S_IFREG | 0444,
+				 priv->node_tbl_root, priv,
+				 &hsr_node_table_fops);
+	if (IS_ERR(de)) {
+		pr_err("Cannot create hsr node_table file\n");
+		debugfs_remove(priv->node_tbl_root);
+		priv->node_tbl_root = NULL;
+		return;
+	}
+}
+
+/* hsr_debugfs_term - Tear down debugfs intrastructure
+ *
+ * Description:
+ * When Debugfs is configured this routine removes debugfs file system
+ * elements that are specific to hsr
+ */
+void
+hsr_debugfs_term(struct hsr_priv *priv)
+{
+	debugfs_remove_recursive(priv->node_tbl_root);
+	priv->node_tbl_root = NULL;
+}
+
+void hsr_debugfs_create_root(void)
+{
+	hsr_debugfs_root_dir = debugfs_create_dir("hsr", NULL);
+	if (IS_ERR(hsr_debugfs_root_dir)) {
+		pr_err("Cannot create hsr debugfs root directory\n");
+		hsr_debugfs_root_dir = NULL;
+	}
+}
+
+void hsr_debugfs_remove_root(void)
+{
+	/* debugfs_remove() internally checks NULL and ERROR */
+	debugfs_remove(hsr_debugfs_root_dir);
+}
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
new file mode 100644
index 000000000..306f942c3
--- /dev/null
+++ b/net/hsr/hsr_device.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ * This file contains device methods for creating, using and destroying
+ * virtual HSR or PRP devices.
+ */
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/pkt_sched.h>
+#include "hsr_device.h"
+#include "hsr_slave.h"
+#include "hsr_framereg.h"
+#include "hsr_main.h"
+#include "hsr_forward.h"
+
+static bool is_admin_up(struct net_device *dev)
+{
+	return dev && (dev->flags & IFF_UP);
+}
+
+static bool is_slave_up(struct net_device *dev)
+{
+	return dev && is_admin_up(dev) && netif_oper_up(dev);
+}
+
+static void __hsr_set_operstate(struct net_device *dev, int transition)
+{
+	write_lock(&dev_base_lock);
+	if (dev->operstate != transition) {
+		dev->operstate = transition;
+		write_unlock(&dev_base_lock);
+		netdev_state_change(dev);
+	} else {
+		write_unlock(&dev_base_lock);
+	}
+}
+
+static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
+{
+	if (!is_admin_up(master->dev)) {
+		__hsr_set_operstate(master->dev, IF_OPER_DOWN);
+		return;
+	}
+
+	if (has_carrier)
+		__hsr_set_operstate(master->dev, IF_OPER_UP);
+	else
+		__hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
+}
+
+static bool hsr_check_carrier(struct hsr_port *master)
+{
+	struct hsr_port *port;
+
+	ASSERT_RTNL();
+
+	hsr_for_each_port(master->hsr, port) {
+		if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
+			netif_carrier_on(master->dev);
+			return true;
+		}
+	}
+
+	netif_carrier_off(master->dev);
+
+	return false;
+}
+
+static void hsr_check_announce(struct net_device *hsr_dev,
+			       unsigned char old_operstate)
+{
+	struct hsr_priv *hsr;
+
+	hsr = netdev_priv(hsr_dev);
+
+	if (hsr_dev->operstate == IF_OPER_UP && old_operstate != IF_OPER_UP) {
+		/* Went up */
+		hsr->announce_count = 0;
+		mod_timer(&hsr->announce_timer,
+			  jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
+	}
+
+	if (hsr_dev->operstate != IF_OPER_UP && old_operstate == IF_OPER_UP)
+		/* Went down */
+		del_timer(&hsr->announce_timer);
+}
+
+void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
+{
+	struct hsr_port *master;
+	unsigned char old_operstate;
+	bool has_carrier;
+
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	/* netif_stacked_transfer_operstate() cannot be used here since
+	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
+	 */
+	old_operstate = master->dev->operstate;
+	has_carrier = hsr_check_carrier(master);
+	hsr_set_operstate(master, has_carrier);
+	hsr_check_announce(master->dev, old_operstate);
+}
+
+int hsr_get_max_mtu(struct hsr_priv *hsr)
+{
+	unsigned int mtu_max;
+	struct hsr_port *port;
+
+	mtu_max = ETH_DATA_LEN;
+	hsr_for_each_port(hsr, port)
+		if (port->type != HSR_PT_MASTER)
+			mtu_max = min(port->dev->mtu, mtu_max);
+
+	if (mtu_max < HSR_HLEN)
+		return 0;
+	return mtu_max - HSR_HLEN;
+}
+
+static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct hsr_priv *hsr;
+
+	hsr = netdev_priv(dev);
+
+	if (new_mtu > hsr_get_max_mtu(hsr)) {
+		netdev_info(dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
+			    HSR_HLEN);
+		return -EINVAL;
+	}
+
+	dev->mtu = new_mtu;
+
+	return 0;
+}
+
+static int hsr_dev_open(struct net_device *dev)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *port;
+	char designation;
+
+	hsr = netdev_priv(dev);
+	designation = '\0';
+
+	hsr_for_each_port(hsr, port) {
+		if (port->type == HSR_PT_MASTER)
+			continue;
+		switch (port->type) {
+		case HSR_PT_SLAVE_A:
+			designation = 'A';
+			break;
+		case HSR_PT_SLAVE_B:
+			designation = 'B';
+			break;
+		default:
+			designation = '?';
+		}
+		if (!is_slave_up(port->dev))
+			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
+				    designation, port->dev->name);
+	}
+
+	if (designation == '\0')
+		netdev_warn(dev, "No slave devices configured\n");
+
+	return 0;
+}
+
+static int hsr_dev_close(struct net_device *dev)
+{
+	/* Nothing to do here. */
+	return 0;
+}
+
+static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
+						netdev_features_t features)
+{
+	netdev_features_t mask;
+	struct hsr_port *port;
+
+	mask = features;
+
+	/* Mask out all features that, if supported by one device, should be
+	 * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
+	 *
+	 * Anything that's off in mask will not be enabled - so only things
+	 * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
+	 * may become enabled.
+	 */
+	features &= ~NETIF_F_ONE_FOR_ALL;
+	hsr_for_each_port(hsr, port)
+		features = netdev_increment_features(features,
+						     port->dev->features,
+						     mask);
+
+	return features;
+}
+
+static netdev_features_t hsr_fix_features(struct net_device *dev,
+					  netdev_features_t features)
+{
+	struct hsr_priv *hsr = netdev_priv(dev);
+
+	return hsr_features_recompute(hsr, features);
+}
+
+static netdev_tx_t hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct hsr_priv *hsr = netdev_priv(dev);
+	struct hsr_port *master;
+
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	if (master) {
+		skb->dev = master->dev;
+		skb_reset_mac_header(skb);
+		skb_reset_mac_len(skb);
+		spin_lock_bh(&hsr->seqnr_lock);
+		hsr_forward_skb(skb, master);
+		spin_unlock_bh(&hsr->seqnr_lock);
+	} else {
+		dev_core_stats_tx_dropped_inc(dev);
+		dev_kfree_skb_any(skb);
+	}
+	return NETDEV_TX_OK;
+}
+
+static const struct header_ops hsr_header_ops = {
+	.create	 = eth_header,
+	.parse	 = eth_header_parse,
+};
+
+static struct sk_buff *hsr_init_skb(struct hsr_port *master)
+{
+	struct hsr_priv *hsr = master->hsr;
+	struct sk_buff *skb;
+	int hlen, tlen;
+
+	hlen = LL_RESERVED_SPACE(master->dev);
+	tlen = master->dev->needed_tailroom;
+	/* skb size is same for PRP/HSR frames, only difference
+	 * being, for PRP it is a trailer and for HSR it is a
+	 * header
+	 */
+	skb = dev_alloc_skb(sizeof(struct hsr_sup_tag) +
+			    sizeof(struct hsr_sup_payload) + hlen + tlen);
+
+	if (!skb)
+		return skb;
+
+	skb_reserve(skb, hlen);
+	skb->dev = master->dev;
+	skb->priority = TC_PRIO_CONTROL;
+
+	if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
+			    hsr->sup_multicast_addr,
+			    skb->dev->dev_addr, skb->len) <= 0)
+		goto out;
+
+	skb_reset_mac_header(skb);
+	skb_reset_mac_len(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	return skb;
+out:
+	kfree_skb(skb);
+
+	return NULL;
+}
+
+static void send_hsr_supervision_frame(struct hsr_port *master,
+				       unsigned long *interval)
+{
+	struct hsr_priv *hsr = master->hsr;
+	__u8 type = HSR_TLV_LIFE_CHECK;
+	struct hsr_sup_payload *hsr_sp;
+	struct hsr_sup_tag *hsr_stag;
+	struct sk_buff *skb;
+
+	*interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
+	if (hsr->announce_count < 3 && hsr->prot_version == 0) {
+		type = HSR_TLV_ANNOUNCE;
+		*interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
+		hsr->announce_count++;
+	}
+
+	skb = hsr_init_skb(master);
+	if (!skb) {
+		WARN_ONCE(1, "HSR: Could not send supervision frame\n");
+		return;
+	}
+
+	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
+	set_hsr_stag_path(hsr_stag, (hsr->prot_version ? 0x0 : 0xf));
+	set_hsr_stag_HSR_ver(hsr_stag, hsr->prot_version);
+
+	/* From HSRv1 on we have separate supervision sequence numbers. */
+	spin_lock_bh(&hsr->seqnr_lock);
+	if (hsr->prot_version > 0) {
+		hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr);
+		hsr->sup_sequence_nr++;
+	} else {
+		hsr_stag->sequence_nr = htons(hsr->sequence_nr);
+		hsr->sequence_nr++;
+	}
+
+	hsr_stag->tlv.HSR_TLV_type = type;
+	/* TODO: Why 12 in HSRv0? */
+	hsr_stag->tlv.HSR_TLV_length = hsr->prot_version ?
+				sizeof(struct hsr_sup_payload) : 12;
+
+	/* Payload: MacAddressA */
+	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
+	ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
+
+	if (skb_put_padto(skb, ETH_ZLEN)) {
+		spin_unlock_bh(&hsr->seqnr_lock);
+		return;
+	}
+
+	hsr_forward_skb(skb, master);
+	spin_unlock_bh(&hsr->seqnr_lock);
+	return;
+}
+
+static void send_prp_supervision_frame(struct hsr_port *master,
+				       unsigned long *interval)
+{
+	struct hsr_priv *hsr = master->hsr;
+	struct hsr_sup_payload *hsr_sp;
+	struct hsr_sup_tag *hsr_stag;
+	struct sk_buff *skb;
+
+	skb = hsr_init_skb(master);
+	if (!skb) {
+		WARN_ONCE(1, "PRP: Could not send supervision frame\n");
+		return;
+	}
+
+	*interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
+	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
+	set_hsr_stag_path(hsr_stag, (hsr->prot_version ? 0x0 : 0xf));
+	set_hsr_stag_HSR_ver(hsr_stag, (hsr->prot_version ? 1 : 0));
+
+	/* From HSRv1 on we have separate supervision sequence numbers. */
+	spin_lock_bh(&hsr->seqnr_lock);
+	hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr);
+	hsr->sup_sequence_nr++;
+	hsr_stag->tlv.HSR_TLV_type = PRP_TLV_LIFE_CHECK_DD;
+	hsr_stag->tlv.HSR_TLV_length = sizeof(struct hsr_sup_payload);
+
+	/* Payload: MacAddressA */
+	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
+	ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
+
+	if (skb_put_padto(skb, ETH_ZLEN)) {
+		spin_unlock_bh(&hsr->seqnr_lock);
+		return;
+	}
+
+	hsr_forward_skb(skb, master);
+	spin_unlock_bh(&hsr->seqnr_lock);
+}
+
+/* Announce (supervision frame) timer function
+ */
+static void hsr_announce(struct timer_list *t)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *master;
+	unsigned long interval;
+
+	hsr = from_timer(hsr, t, announce_timer);
+
+	rcu_read_lock();
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	hsr->proto_ops->send_sv_frame(master, &interval);
+
+	if (is_admin_up(master->dev))
+		mod_timer(&hsr->announce_timer, jiffies + interval);
+
+	rcu_read_unlock();
+}
+
+void hsr_del_ports(struct hsr_priv *hsr)
+{
+	struct hsr_port *port;
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (port)
+		hsr_del_port(port);
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+	if (port)
+		hsr_del_port(port);
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	if (port)
+		hsr_del_port(port);
+}
+
+static const struct net_device_ops hsr_device_ops = {
+	.ndo_change_mtu = hsr_dev_change_mtu,
+	.ndo_open = hsr_dev_open,
+	.ndo_stop = hsr_dev_close,
+	.ndo_start_xmit = hsr_dev_xmit,
+	.ndo_fix_features = hsr_fix_features,
+};
+
+static struct device_type hsr_type = {
+	.name = "hsr",
+};
+
+static struct hsr_proto_ops hsr_ops = {
+	.send_sv_frame = send_hsr_supervision_frame,
+	.create_tagged_frame = hsr_create_tagged_frame,
+	.get_untagged_frame = hsr_get_untagged_frame,
+	.drop_frame = hsr_drop_frame,
+	.fill_frame_info = hsr_fill_frame_info,
+	.invalid_dan_ingress_frame = hsr_invalid_dan_ingress_frame,
+};
+
+static struct hsr_proto_ops prp_ops = {
+	.send_sv_frame = send_prp_supervision_frame,
+	.create_tagged_frame = prp_create_tagged_frame,
+	.get_untagged_frame = prp_get_untagged_frame,
+	.drop_frame = prp_drop_frame,
+	.fill_frame_info = prp_fill_frame_info,
+	.handle_san_frame = prp_handle_san_frame,
+	.update_san_info = prp_update_san_info,
+};
+
+void hsr_dev_setup(struct net_device *dev)
+{
+	eth_hw_addr_random(dev);
+
+	ether_setup(dev);
+	dev->min_mtu = 0;
+	dev->header_ops = &hsr_header_ops;
+	dev->netdev_ops = &hsr_device_ops;
+	SET_NETDEV_DEVTYPE(dev, &hsr_type);
+	dev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
+
+	dev->needs_free_netdev = true;
+
+	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
+			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
+			   NETIF_F_HW_VLAN_CTAG_TX;
+
+	dev->features = dev->hw_features;
+
+	/* Prevent recursive tx locking */
+	dev->features |= NETIF_F_LLTX;
+	/* VLAN on top of HSR needs testing and probably some work on
+	 * hsr_header_create() etc.
+	 */
+	dev->features |= NETIF_F_VLAN_CHALLENGED;
+	/* Not sure about this. Taken from bridge code. netdev_features.h says
+	 * it means "Does not change network namespaces".
+	 */
+	dev->features |= NETIF_F_NETNS_LOCAL;
+}
+
+/* Return true if dev is a HSR master; return false otherwise.
+ */
+bool is_hsr_master(struct net_device *dev)
+{
+	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
+}
+EXPORT_SYMBOL(is_hsr_master);
+
+/* Default multicast address for HSR Supervision frames */
+static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
+	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
+};
+
+int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
+		     unsigned char multicast_spec, u8 protocol_version,
+		     struct netlink_ext_ack *extack)
+{
+	bool unregister = false;
+	struct hsr_priv *hsr;
+	int res;
+
+	hsr = netdev_priv(hsr_dev);
+	INIT_LIST_HEAD(&hsr->ports);
+	INIT_LIST_HEAD(&hsr->node_db);
+	spin_lock_init(&hsr->list_lock);
+
+	eth_hw_addr_set(hsr_dev, slave[0]->dev_addr);
+
+	/* initialize protocol specific functions */
+	if (protocol_version == PRP_V1) {
+		/* For PRP, lan_id has most significant 3 bits holding
+		 * the net_id of PRP_LAN_ID
+		 */
+		hsr->net_id = PRP_LAN_ID << 1;
+		hsr->proto_ops = &prp_ops;
+	} else {
+		hsr->proto_ops = &hsr_ops;
+	}
+
+	/* Make sure we recognize frames from ourselves in hsr_rcv() */
+	res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
+				   slave[1]->dev_addr);
+	if (res < 0)
+		return res;
+
+	spin_lock_init(&hsr->seqnr_lock);
+	/* Overflow soon to find bugs easier: */
+	hsr->sequence_nr = HSR_SEQNR_START;
+	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
+
+	timer_setup(&hsr->announce_timer, hsr_announce, 0);
+	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
+
+	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
+	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
+
+	hsr->prot_version = protocol_version;
+
+	/* Make sure the 1st call to netif_carrier_on() gets through */
+	netif_carrier_off(hsr_dev);
+
+	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER, extack);
+	if (res)
+		goto err_add_master;
+
+	/* HSR forwarding offload supported in lower device? */
+	if ((slave[0]->features & NETIF_F_HW_HSR_FWD) &&
+	    (slave[1]->features & NETIF_F_HW_HSR_FWD))
+		hsr->fwd_offloaded = true;
+
+	res = register_netdevice(hsr_dev);
+	if (res)
+		goto err_unregister;
+
+	unregister = true;
+
+	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A, extack);
+	if (res)
+		goto err_unregister;
+
+	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B, extack);
+	if (res)
+		goto err_unregister;
+
+	hsr_debugfs_init(hsr, hsr_dev);
+	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
+
+	return 0;
+
+err_unregister:
+	hsr_del_ports(hsr);
+err_add_master:
+	hsr_del_self_node(hsr);
+
+	if (unregister)
+		unregister_netdevice(hsr_dev);
+	return res;
+}
diff --git a/net/hsr/hsr_device.h b/net/hsr/hsr_device.h
new file mode 100644
index 000000000..9060c9216
--- /dev/null
+++ b/net/hsr/hsr_device.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
+ */
+
+#ifndef __HSR_DEVICE_H
+#define __HSR_DEVICE_H
+
+#include <linux/netdevice.h>
+#include "hsr_main.h"
+
+void hsr_del_ports(struct hsr_priv *hsr);
+void hsr_dev_setup(struct net_device *dev);
+int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
+		     unsigned char multicast_spec, u8 protocol_version,
+		     struct netlink_ext_ack *extack);
+void hsr_check_carrier_and_operstate(struct hsr_priv *hsr);
+int hsr_get_max_mtu(struct hsr_priv *hsr);
+#endif /* __HSR_DEVICE_H */
diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
new file mode 100644
index 000000000..80cdc6f6b
--- /dev/null
+++ b/net/hsr/hsr_forward.c
@@ -0,0 +1,638 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * Frame router for HSR and PRP.
+ */
+
+#include "hsr_forward.h"
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include "hsr_main.h"
+#include "hsr_framereg.h"
+
+struct hsr_node;
+
+/* The uses I can see for these HSR supervision frames are:
+ * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
+ *    22") to reset any sequence_nr counters belonging to that node. Useful if
+ *    the other node's counter has been reset for some reason.
+ *    --
+ *    Or not - resetting the counter and bridging the frame would create a
+ *    loop, unfortunately.
+ *
+ * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
+ *    frame is received from a particular node, we know something is wrong.
+ *    We just register these (as with normal frames) and throw them away.
+ *
+ * 3) Allow different MAC addresses for the two slave interfaces, using the
+ *    MacAddressA field.
+ */
+static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
+{
+	struct ethhdr *eth_hdr;
+	struct hsr_sup_tag *hsr_sup_tag;
+	struct hsrv1_ethhdr_sp *hsr_V1_hdr;
+	struct hsr_sup_tlv *hsr_sup_tlv;
+	u16 total_length = 0;
+
+	WARN_ON_ONCE(!skb_mac_header_was_set(skb));
+	eth_hdr = (struct ethhdr *)skb_mac_header(skb);
+
+	/* Correct addr? */
+	if (!ether_addr_equal(eth_hdr->h_dest,
+			      hsr->sup_multicast_addr))
+		return false;
+
+	/* Correct ether type?. */
+	if (!(eth_hdr->h_proto == htons(ETH_P_PRP) ||
+	      eth_hdr->h_proto == htons(ETH_P_HSR)))
+		return false;
+
+	/* Get the supervision header from correct location. */
+	if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */
+		total_length = sizeof(struct hsrv1_ethhdr_sp);
+		if (!pskb_may_pull(skb, total_length))
+			return false;
+
+		hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb);
+		if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP))
+			return false;
+
+		hsr_sup_tag = &hsr_V1_hdr->hsr_sup;
+	} else {
+		total_length = sizeof(struct hsrv0_ethhdr_sp);
+		if (!pskb_may_pull(skb, total_length))
+			return false;
+
+		hsr_sup_tag =
+		     &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup;
+	}
+
+	if (hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_ANNOUNCE &&
+	    hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_LIFE_CHECK &&
+	    hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DD &&
+	    hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DA)
+		return false;
+	if (hsr_sup_tag->tlv.HSR_TLV_length != 12 &&
+	    hsr_sup_tag->tlv.HSR_TLV_length != sizeof(struct hsr_sup_payload))
+		return false;
+
+	/* Get next tlv */
+	total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tag->tlv.HSR_TLV_length;
+	if (!pskb_may_pull(skb, total_length))
+		return false;
+	skb_pull(skb, total_length);
+	hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
+	skb_push(skb, total_length);
+
+	/* if this is a redbox supervision frame we need to verify
+	 * that more data is available
+	 */
+	if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
+		/* tlv length must be a length of a mac address */
+		if (hsr_sup_tlv->HSR_TLV_length != sizeof(struct hsr_sup_payload))
+			return false;
+
+		/* make sure another tlv follows */
+		total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tlv->HSR_TLV_length;
+		if (!pskb_may_pull(skb, total_length))
+			return false;
+
+		/* get next tlv */
+		skb_pull(skb, total_length);
+		hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
+		skb_push(skb, total_length);
+	}
+
+	/* end of tlvs must follow at the end */
+	if (hsr_sup_tlv->HSR_TLV_type == HSR_TLV_EOT &&
+	    hsr_sup_tlv->HSR_TLV_length != 0)
+		return false;
+
+	return true;
+}
+
+static struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in,
+					       struct hsr_frame_info *frame)
+{
+	struct sk_buff *skb;
+	int copylen;
+	unsigned char *dst, *src;
+
+	skb_pull(skb_in, HSR_HLEN);
+	skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
+	skb_push(skb_in, HSR_HLEN);
+	if (!skb)
+		return NULL;
+
+	skb_reset_mac_header(skb);
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL)
+		skb->csum_start -= HSR_HLEN;
+
+	copylen = 2 * ETH_ALEN;
+	if (frame->is_vlan)
+		copylen += VLAN_HLEN;
+	src = skb_mac_header(skb_in);
+	dst = skb_mac_header(skb);
+	memcpy(dst, src, copylen);
+
+	skb->protocol = eth_hdr(skb)->h_proto;
+	return skb;
+}
+
+struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
+				       struct hsr_port *port)
+{
+	if (!frame->skb_std) {
+		if (frame->skb_hsr)
+			frame->skb_std =
+				create_stripped_skb_hsr(frame->skb_hsr, frame);
+		else
+			netdev_warn_once(port->dev,
+					 "Unexpected frame received in hsr_get_untagged_frame()\n");
+
+		if (!frame->skb_std)
+			return NULL;
+	}
+
+	return skb_clone(frame->skb_std, GFP_ATOMIC);
+}
+
+struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
+				       struct hsr_port *port)
+{
+	if (!frame->skb_std) {
+		if (frame->skb_prp) {
+			/* trim the skb by len - HSR_HLEN to exclude RCT */
+			skb_trim(frame->skb_prp,
+				 frame->skb_prp->len - HSR_HLEN);
+			frame->skb_std =
+				__pskb_copy(frame->skb_prp,
+					    skb_headroom(frame->skb_prp),
+					    GFP_ATOMIC);
+		} else {
+			/* Unexpected */
+			WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
+				  __FILE__, __LINE__, port->dev->name);
+			return NULL;
+		}
+	}
+
+	return skb_clone(frame->skb_std, GFP_ATOMIC);
+}
+
+static void prp_set_lan_id(struct prp_rct *trailer,
+			   struct hsr_port *port)
+{
+	int lane_id;
+
+	if (port->type == HSR_PT_SLAVE_A)
+		lane_id = 0;
+	else
+		lane_id = 1;
+
+	/* Add net_id in the upper 3 bits of lane_id */
+	lane_id |= port->hsr->net_id;
+	set_prp_lan_id(trailer, lane_id);
+}
+
+/* Tailroom for PRP rct should have been created before calling this */
+static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
+				    struct hsr_frame_info *frame,
+				    struct hsr_port *port)
+{
+	struct prp_rct *trailer;
+	int min_size = ETH_ZLEN;
+	int lsdu_size;
+
+	if (!skb)
+		return skb;
+
+	if (frame->is_vlan)
+		min_size = VLAN_ETH_ZLEN;
+
+	if (skb_put_padto(skb, min_size))
+		return NULL;
+
+	trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
+	lsdu_size = skb->len - 14;
+	if (frame->is_vlan)
+		lsdu_size -= 4;
+	prp_set_lan_id(trailer, port);
+	set_prp_LSDU_size(trailer, lsdu_size);
+	trailer->sequence_nr = htons(frame->sequence_nr);
+	trailer->PRP_suffix = htons(ETH_P_PRP);
+	skb->protocol = eth_hdr(skb)->h_proto;
+
+	return skb;
+}
+
+static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr,
+			    struct hsr_port *port)
+{
+	int path_id;
+
+	if (port->type == HSR_PT_SLAVE_A)
+		path_id = 0;
+	else
+		path_id = 1;
+
+	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
+}
+
+static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
+				    struct hsr_frame_info *frame,
+				    struct hsr_port *port, u8 proto_version)
+{
+	struct hsr_ethhdr *hsr_ethhdr;
+	int lsdu_size;
+
+	/* pad to minimum packet size which is 60 + 6 (HSR tag) */
+	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
+		return NULL;
+
+	lsdu_size = skb->len - 14;
+	if (frame->is_vlan)
+		lsdu_size -= 4;
+
+	hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
+
+	hsr_set_path_id(hsr_ethhdr, port);
+	set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
+	hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
+	hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
+	hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
+			ETH_P_HSR : ETH_P_PRP);
+	skb->protocol = hsr_ethhdr->ethhdr.h_proto;
+
+	return skb;
+}
+
+/* If the original frame was an HSR tagged frame, just clone it to be sent
+ * unchanged. Otherwise, create a private frame especially tagged for 'port'.
+ */
+struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
+					struct hsr_port *port)
+{
+	unsigned char *dst, *src;
+	struct sk_buff *skb;
+	int movelen;
+
+	if (frame->skb_hsr) {
+		struct hsr_ethhdr *hsr_ethhdr =
+			(struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);
+
+		/* set the lane id properly */
+		hsr_set_path_id(hsr_ethhdr, port);
+		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
+	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
+		return skb_clone(frame->skb_std, GFP_ATOMIC);
+	}
+
+	/* Create the new skb with enough headroom to fit the HSR tag */
+	skb = __pskb_copy(frame->skb_std,
+			  skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
+	if (!skb)
+		return NULL;
+	skb_reset_mac_header(skb);
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL)
+		skb->csum_start += HSR_HLEN;
+
+	movelen = ETH_HLEN;
+	if (frame->is_vlan)
+		movelen += VLAN_HLEN;
+
+	src = skb_mac_header(skb);
+	dst = skb_push(skb, HSR_HLEN);
+	memmove(dst, src, movelen);
+	skb_reset_mac_header(skb);
+
+	/* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
+	 * that case
+	 */
+	return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
+}
+
+struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
+					struct hsr_port *port)
+{
+	struct sk_buff *skb;
+
+	if (frame->skb_prp) {
+		struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);
+
+		if (trailer) {
+			prp_set_lan_id(trailer, port);
+		} else {
+			WARN_ONCE(!trailer, "errored PRP skb");
+			return NULL;
+		}
+		return skb_clone(frame->skb_prp, GFP_ATOMIC);
+	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
+		return skb_clone(frame->skb_std, GFP_ATOMIC);
+	}
+
+	skb = skb_copy_expand(frame->skb_std, 0,
+			      skb_tailroom(frame->skb_std) + HSR_HLEN,
+			      GFP_ATOMIC);
+	return prp_fill_rct(skb, frame, port);
+}
+
+static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
+			       struct hsr_node *node_src)
+{
+	bool was_multicast_frame;
+	int res, recv_len;
+
+	was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
+	hsr_addr_subst_source(node_src, skb);
+	skb_pull(skb, ETH_HLEN);
+	recv_len = skb->len;
+	res = netif_rx(skb);
+	if (res == NET_RX_DROP) {
+		dev->stats.rx_dropped++;
+	} else {
+		dev->stats.rx_packets++;
+		dev->stats.rx_bytes += recv_len;
+		if (was_multicast_frame)
+			dev->stats.multicast++;
+	}
+}
+
+static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
+		    struct hsr_frame_info *frame)
+{
+	if (frame->port_rcv->type == HSR_PT_MASTER) {
+		hsr_addr_subst_dest(frame->node_src, skb, port);
+
+		/* Address substitution (IEC62439-3 pp 26, 50): replace mac
+		 * address of outgoing frame with that of the outgoing slave's.
+		 */
+		ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
+	}
+	return dev_queue_xmit(skb);
+}
+
+bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
+{
+	return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
+		 port->type ==  HSR_PT_SLAVE_B) ||
+		(frame->port_rcv->type == HSR_PT_SLAVE_B &&
+		 port->type ==  HSR_PT_SLAVE_A));
+}
+
+bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
+{
+	if (port->dev->features & NETIF_F_HW_HSR_FWD)
+		return prp_drop_frame(frame, port);
+
+	return false;
+}
+
+/* Forward the frame through all devices except:
+ * - Back through the receiving device
+ * - If it's a HSR frame: through a device where it has passed before
+ * - if it's a PRP frame: through another PRP slave device (no bridge)
+ * - To the local HSR master only if the frame is directly addressed to it, or
+ *   a non-supervision multicast or broadcast frame.
+ *
+ * HSR slave devices should insert a HSR tag into the frame, or forward the
+ * frame unchanged if it's already tagged. Interlink devices should strip HSR
+ * tags if they're of the non-HSR type (but only after duplicate discard). The
+ * master device always strips HSR tags.
+ */
+static void hsr_forward_do(struct hsr_frame_info *frame)
+{
+	struct hsr_port *port;
+	struct sk_buff *skb;
+	bool sent = false;
+
+	hsr_for_each_port(frame->port_rcv->hsr, port) {
+		struct hsr_priv *hsr = port->hsr;
+		/* Don't send frame back the way it came */
+		if (port == frame->port_rcv)
+			continue;
+
+		/* Don't deliver locally unless we should */
+		if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
+			continue;
+
+		/* Deliver frames directly addressed to us to master only */
+		if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
+			continue;
+
+		/* If hardware duplicate generation is enabled, only send out
+		 * one port.
+		 */
+		if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
+			continue;
+
+		/* Don't send frame over port where it has been sent before.
+		 * Also fro SAN, this shouldn't be done.
+		 */
+		if (!frame->is_from_san &&
+		    hsr_register_frame_out(port, frame->node_src,
+					   frame->sequence_nr))
+			continue;
+
+		if (frame->is_supervision && port->type == HSR_PT_MASTER) {
+			hsr_handle_sup_frame(frame);
+			continue;
+		}
+
+		/* Check if frame is to be dropped. Eg. for PRP no forward
+		 * between ports.
+		 */
+		if (hsr->proto_ops->drop_frame &&
+		    hsr->proto_ops->drop_frame(frame, port))
+			continue;
+
+		if (port->type != HSR_PT_MASTER)
+			skb = hsr->proto_ops->create_tagged_frame(frame, port);
+		else
+			skb = hsr->proto_ops->get_untagged_frame(frame, port);
+
+		if (!skb) {
+			frame->port_rcv->dev->stats.rx_dropped++;
+			continue;
+		}
+
+		skb->dev = port->dev;
+		if (port->type == HSR_PT_MASTER) {
+			hsr_deliver_master(skb, port->dev, frame->node_src);
+		} else {
+			if (!hsr_xmit(skb, port, frame))
+				sent = true;
+		}
+	}
+}
+
+static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
+			     struct hsr_frame_info *frame)
+{
+	if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
+		frame->is_local_exclusive = true;
+		skb->pkt_type = PACKET_HOST;
+	} else {
+		frame->is_local_exclusive = false;
+	}
+
+	if (skb->pkt_type == PACKET_HOST ||
+	    skb->pkt_type == PACKET_MULTICAST ||
+	    skb->pkt_type == PACKET_BROADCAST) {
+		frame->is_local_dest = true;
+	} else {
+		frame->is_local_dest = false;
+	}
+}
+
+static void handle_std_frame(struct sk_buff *skb,
+			     struct hsr_frame_info *frame)
+{
+	struct hsr_port *port = frame->port_rcv;
+	struct hsr_priv *hsr = port->hsr;
+
+	frame->skb_hsr = NULL;
+	frame->skb_prp = NULL;
+	frame->skb_std = skb;
+
+	if (port->type != HSR_PT_MASTER) {
+		frame->is_from_san = true;
+	} else {
+		/* Sequence nr for the master node */
+		lockdep_assert_held(&hsr->seqnr_lock);
+		frame->sequence_nr = hsr->sequence_nr;
+		hsr->sequence_nr++;
+	}
+}
+
+int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
+			struct hsr_frame_info *frame)
+{
+	struct hsr_port *port = frame->port_rcv;
+	struct hsr_priv *hsr = port->hsr;
+
+	/* HSRv0 supervisory frames double as a tag so treat them as tagged. */
+	if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
+	    proto == htons(ETH_P_HSR)) {
+		/* Check if skb contains hsr_ethhdr */
+		if (skb->mac_len < sizeof(struct hsr_ethhdr))
+			return -EINVAL;
+
+		/* HSR tagged frame :- Data or Supervision */
+		frame->skb_std = NULL;
+		frame->skb_prp = NULL;
+		frame->skb_hsr = skb;
+		frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
+		return 0;
+	}
+
+	/* Standard frame or PRP from master port */
+	handle_std_frame(skb, frame);
+
+	return 0;
+}
+
+int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
+			struct hsr_frame_info *frame)
+{
+	/* Supervision frame */
+	struct prp_rct *rct = skb_get_PRP_rct(skb);
+
+	if (rct &&
+	    prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
+		frame->skb_hsr = NULL;
+		frame->skb_std = NULL;
+		frame->skb_prp = skb;
+		frame->sequence_nr = prp_get_skb_sequence_nr(rct);
+		return 0;
+	}
+	handle_std_frame(skb, frame);
+
+	return 0;
+}
+
+static int fill_frame_info(struct hsr_frame_info *frame,
+			   struct sk_buff *skb, struct hsr_port *port)
+{
+	struct hsr_priv *hsr = port->hsr;
+	struct hsr_vlan_ethhdr *vlan_hdr;
+	struct ethhdr *ethhdr;
+	__be16 proto;
+	int ret;
+
+	/* Check if skb contains ethhdr */
+	if (skb->mac_len < sizeof(struct ethhdr))
+		return -EINVAL;
+
+	memset(frame, 0, sizeof(*frame));
+	frame->is_supervision = is_supervision_frame(port->hsr, skb);
+	frame->node_src = hsr_get_node(port, &hsr->node_db, skb,
+				       frame->is_supervision,
+				       port->type);
+	if (!frame->node_src)
+		return -1; /* Unknown node and !is_supervision, or no mem */
+
+	ethhdr = (struct ethhdr *)skb_mac_header(skb);
+	frame->is_vlan = false;
+	proto = ethhdr->h_proto;
+
+	if (proto == htons(ETH_P_8021Q))
+		frame->is_vlan = true;
+
+	if (frame->is_vlan) {
+		vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
+		proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
+		/* FIXME: */
+		netdev_warn_once(skb->dev, "VLAN not yet supported");
+		return -EINVAL;
+	}
+
+	frame->is_from_san = false;
+	frame->port_rcv = port;
+	ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
+	if (ret)
+		return ret;
+
+	check_local_dest(port->hsr, skb, frame);
+
+	return 0;
+}
+
+/* Must be called holding rcu read lock (because of the port parameter) */
+void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
+{
+	struct hsr_frame_info frame;
+
+	rcu_read_lock();
+	if (fill_frame_info(&frame, skb, port) < 0)
+		goto out_drop;
+
+	hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
+	hsr_forward_do(&frame);
+	rcu_read_unlock();
+	/* Gets called for ingress frames as well as egress from master port.
+	 * So check and increment stats for master port only here.
+	 */
+	if (port->type == HSR_PT_MASTER) {
+		port->dev->stats.tx_packets++;
+		port->dev->stats.tx_bytes += skb->len;
+	}
+
+	kfree_skb(frame.skb_hsr);
+	kfree_skb(frame.skb_prp);
+	kfree_skb(frame.skb_std);
+	return;
+
+out_drop:
+	rcu_read_unlock();
+	port->dev->stats.tx_dropped++;
+	kfree_skb(skb);
+}
diff --git a/net/hsr/hsr_forward.h b/net/hsr/hsr_forward.h
new file mode 100644
index 000000000..206636750
--- /dev/null
+++ b/net/hsr/hsr_forward.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
+ */
+
+#ifndef __HSR_FORWARD_H
+#define __HSR_FORWARD_H
+
+#include <linux/netdevice.h>
+#include "hsr_main.h"
+
+void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port);
+struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
+					struct hsr_port *port);
+struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
+					struct hsr_port *port);
+struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
+				       struct hsr_port *port);
+struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
+				       struct hsr_port *port);
+bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port);
+bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port);
+int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
+			struct hsr_frame_info *frame);
+int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
+			struct hsr_frame_info *frame);
+#endif /* __HSR_FORWARD_H */
diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
new file mode 100644
index 000000000..6d14d935e
--- /dev/null
+++ b/net/hsr/hsr_framereg.c
@@ -0,0 +1,633 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * The HSR spec says never to forward the same frame twice on the same
+ * interface. A frame is identified by its source MAC address and its HSR
+ * sequence number. This code keeps track of senders and their sequence numbers
+ * to allow filtering of duplicate frames, and to detect HSR ring errors.
+ * Same code handles filtering of duplicates for PRP as well.
+ */
+
+#include <linux/if_ether.h>
+#include <linux/etherdevice.h>
+#include <linux/slab.h>
+#include <linux/rculist.h>
+#include "hsr_main.h"
+#include "hsr_framereg.h"
+#include "hsr_netlink.h"
+
+/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
+ * false otherwise.
+ */
+static bool seq_nr_after(u16 a, u16 b)
+{
+	/* Remove inconsistency where
+	 * seq_nr_after(a, b) == seq_nr_before(a, b)
+	 */
+	if ((int)b - a == 32768)
+		return false;
+
+	return (((s16)(b - a)) < 0);
+}
+
+#define seq_nr_before(a, b)		seq_nr_after((b), (a))
+#define seq_nr_before_or_eq(a, b)	(!seq_nr_after((a), (b)))
+
+bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
+{
+	struct hsr_self_node *sn;
+	bool ret = false;
+
+	rcu_read_lock();
+	sn = rcu_dereference(hsr->self_node);
+	if (!sn) {
+		WARN_ONCE(1, "HSR: No self node\n");
+		goto out;
+	}
+
+	if (ether_addr_equal(addr, sn->macaddress_A) ||
+	    ether_addr_equal(addr, sn->macaddress_B))
+		ret = true;
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+/* Search for mac entry. Caller must hold rcu read lock.
+ */
+static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
+					    const unsigned char addr[ETH_ALEN])
+{
+	struct hsr_node *node;
+
+	list_for_each_entry_rcu(node, node_db, mac_list) {
+		if (ether_addr_equal(node->macaddress_A, addr))
+			return node;
+	}
+
+	return NULL;
+}
+
+/* Helper for device init; the self_node is used in hsr_rcv() to recognize
+ * frames from self that's been looped over the HSR ring.
+ */
+int hsr_create_self_node(struct hsr_priv *hsr,
+			 const unsigned char addr_a[ETH_ALEN],
+			 const unsigned char addr_b[ETH_ALEN])
+{
+	struct hsr_self_node *sn, *old;
+
+	sn = kmalloc(sizeof(*sn), GFP_KERNEL);
+	if (!sn)
+		return -ENOMEM;
+
+	ether_addr_copy(sn->macaddress_A, addr_a);
+	ether_addr_copy(sn->macaddress_B, addr_b);
+
+	spin_lock_bh(&hsr->list_lock);
+	old = rcu_replace_pointer(hsr->self_node, sn,
+				  lockdep_is_held(&hsr->list_lock));
+	spin_unlock_bh(&hsr->list_lock);
+
+	if (old)
+		kfree_rcu(old, rcu_head);
+	return 0;
+}
+
+void hsr_del_self_node(struct hsr_priv *hsr)
+{
+	struct hsr_self_node *old;
+
+	spin_lock_bh(&hsr->list_lock);
+	old = rcu_replace_pointer(hsr->self_node, NULL,
+				  lockdep_is_held(&hsr->list_lock));
+	spin_unlock_bh(&hsr->list_lock);
+	if (old)
+		kfree_rcu(old, rcu_head);
+}
+
+void hsr_del_nodes(struct list_head *node_db)
+{
+	struct hsr_node *node;
+	struct hsr_node *tmp;
+
+	list_for_each_entry_safe(node, tmp, node_db, mac_list)
+		kfree(node);
+}
+
+void prp_handle_san_frame(bool san, enum hsr_port_type port,
+			  struct hsr_node *node)
+{
+	/* Mark if the SAN node is over LAN_A or LAN_B */
+	if (port == HSR_PT_SLAVE_A) {
+		node->san_a = true;
+		return;
+	}
+
+	if (port == HSR_PT_SLAVE_B)
+		node->san_b = true;
+}
+
+/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
+ * seq_out is used to initialize filtering of outgoing duplicate frames
+ * originating from the newly added node.
+ */
+static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
+				     struct list_head *node_db,
+				     unsigned char addr[],
+				     u16 seq_out, bool san,
+				     enum hsr_port_type rx_port)
+{
+	struct hsr_node *new_node, *node;
+	unsigned long now;
+	int i;
+
+	new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
+	if (!new_node)
+		return NULL;
+
+	ether_addr_copy(new_node->macaddress_A, addr);
+	spin_lock_init(&new_node->seq_out_lock);
+
+	/* We are only interested in time diffs here, so use current jiffies
+	 * as initialization. (0 could trigger an spurious ring error warning).
+	 */
+	now = jiffies;
+	for (i = 0; i < HSR_PT_PORTS; i++) {
+		new_node->time_in[i] = now;
+		new_node->time_out[i] = now;
+	}
+	for (i = 0; i < HSR_PT_PORTS; i++)
+		new_node->seq_out[i] = seq_out;
+
+	if (san && hsr->proto_ops->handle_san_frame)
+		hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
+
+	spin_lock_bh(&hsr->list_lock);
+	list_for_each_entry_rcu(node, node_db, mac_list,
+				lockdep_is_held(&hsr->list_lock)) {
+		if (ether_addr_equal(node->macaddress_A, addr))
+			goto out;
+		if (ether_addr_equal(node->macaddress_B, addr))
+			goto out;
+	}
+	list_add_tail_rcu(&new_node->mac_list, node_db);
+	spin_unlock_bh(&hsr->list_lock);
+	return new_node;
+out:
+	spin_unlock_bh(&hsr->list_lock);
+	kfree(new_node);
+	return node;
+}
+
+void prp_update_san_info(struct hsr_node *node, bool is_sup)
+{
+	if (!is_sup)
+		return;
+
+	node->san_a = false;
+	node->san_b = false;
+}
+
+/* Get the hsr_node from which 'skb' was sent.
+ */
+struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
+			      struct sk_buff *skb, bool is_sup,
+			      enum hsr_port_type rx_port)
+{
+	struct hsr_priv *hsr = port->hsr;
+	struct hsr_node *node;
+	struct ethhdr *ethhdr;
+	struct prp_rct *rct;
+	bool san = false;
+	u16 seq_out;
+
+	if (!skb_mac_header_was_set(skb))
+		return NULL;
+
+	ethhdr = (struct ethhdr *)skb_mac_header(skb);
+
+	list_for_each_entry_rcu(node, node_db, mac_list) {
+		if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
+			if (hsr->proto_ops->update_san_info)
+				hsr->proto_ops->update_san_info(node, is_sup);
+			return node;
+		}
+		if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
+			if (hsr->proto_ops->update_san_info)
+				hsr->proto_ops->update_san_info(node, is_sup);
+			return node;
+		}
+	}
+
+	/* Everyone may create a node entry, connected node to a HSR/PRP
+	 * device.
+	 */
+	if (ethhdr->h_proto == htons(ETH_P_PRP) ||
+	    ethhdr->h_proto == htons(ETH_P_HSR)) {
+		/* Use the existing sequence_nr from the tag as starting point
+		 * for filtering duplicate frames.
+		 */
+		seq_out = hsr_get_skb_sequence_nr(skb) - 1;
+	} else {
+		rct = skb_get_PRP_rct(skb);
+		if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
+			seq_out = prp_get_skb_sequence_nr(rct);
+		} else {
+			if (rx_port != HSR_PT_MASTER)
+				san = true;
+			seq_out = HSR_SEQNR_START;
+		}
+	}
+
+	return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
+			    san, rx_port);
+}
+
+/* Use the Supervision frame's info about an eventual macaddress_B for merging
+ * nodes that has previously had their macaddress_B registered as a separate
+ * node.
+ */
+void hsr_handle_sup_frame(struct hsr_frame_info *frame)
+{
+	struct hsr_node *node_curr = frame->node_src;
+	struct hsr_port *port_rcv = frame->port_rcv;
+	struct hsr_priv *hsr = port_rcv->hsr;
+	struct hsr_sup_payload *hsr_sp;
+	struct hsr_sup_tlv *hsr_sup_tlv;
+	struct hsr_node *node_real;
+	struct sk_buff *skb = NULL;
+	struct list_head *node_db;
+	struct ethhdr *ethhdr;
+	int i;
+	unsigned int pull_size = 0;
+	unsigned int total_pull_size = 0;
+
+	/* Here either frame->skb_hsr or frame->skb_prp should be
+	 * valid as supervision frame always will have protocol
+	 * header info.
+	 */
+	if (frame->skb_hsr)
+		skb = frame->skb_hsr;
+	else if (frame->skb_prp)
+		skb = frame->skb_prp;
+	else if (frame->skb_std)
+		skb = frame->skb_std;
+	if (!skb)
+		return;
+
+	/* Leave the ethernet header. */
+	pull_size = sizeof(struct ethhdr);
+	skb_pull(skb, pull_size);
+	total_pull_size += pull_size;
+
+	ethhdr = (struct ethhdr *)skb_mac_header(skb);
+
+	/* And leave the HSR tag. */
+	if (ethhdr->h_proto == htons(ETH_P_HSR)) {
+		pull_size = sizeof(struct hsr_tag);
+		skb_pull(skb, pull_size);
+		total_pull_size += pull_size;
+	}
+
+	/* And leave the HSR sup tag. */
+	pull_size = sizeof(struct hsr_sup_tag);
+	skb_pull(skb, pull_size);
+	total_pull_size += pull_size;
+
+	/* get HSR sup payload */
+	hsr_sp = (struct hsr_sup_payload *)skb->data;
+
+	/* Merge node_curr (registered on macaddress_B) into node_real */
+	node_db = &port_rcv->hsr->node_db;
+	node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
+	if (!node_real)
+		/* No frame received from AddrA of this node yet */
+		node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
+					 HSR_SEQNR_START - 1, true,
+					 port_rcv->type);
+	if (!node_real)
+		goto done; /* No mem */
+	if (node_real == node_curr)
+		/* Node has already been merged */
+		goto done;
+
+	/* Leave the first HSR sup payload. */
+	pull_size = sizeof(struct hsr_sup_payload);
+	skb_pull(skb, pull_size);
+	total_pull_size += pull_size;
+
+	/* Get second supervision tlv */
+	hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
+	/* And check if it is a redbox mac TLV */
+	if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
+		/* We could stop here after pushing hsr_sup_payload,
+		 * or proceed and allow macaddress_B and for redboxes.
+		 */
+		/* Sanity check length */
+		if (hsr_sup_tlv->HSR_TLV_length != 6)
+			goto done;
+
+		/* Leave the second HSR sup tlv. */
+		pull_size = sizeof(struct hsr_sup_tlv);
+		skb_pull(skb, pull_size);
+		total_pull_size += pull_size;
+
+		/* Get redbox mac address. */
+		hsr_sp = (struct hsr_sup_payload *)skb->data;
+
+		/* Check if redbox mac and node mac are equal. */
+		if (!ether_addr_equal(node_real->macaddress_A, hsr_sp->macaddress_A)) {
+			/* This is a redbox supervision frame for a VDAN! */
+			goto done;
+		}
+	}
+
+	ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
+	spin_lock_bh(&node_real->seq_out_lock);
+	for (i = 0; i < HSR_PT_PORTS; i++) {
+		if (!node_curr->time_in_stale[i] &&
+		    time_after(node_curr->time_in[i], node_real->time_in[i])) {
+			node_real->time_in[i] = node_curr->time_in[i];
+			node_real->time_in_stale[i] =
+						node_curr->time_in_stale[i];
+		}
+		if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
+			node_real->seq_out[i] = node_curr->seq_out[i];
+	}
+	spin_unlock_bh(&node_real->seq_out_lock);
+	node_real->addr_B_port = port_rcv->type;
+
+	spin_lock_bh(&hsr->list_lock);
+	if (!node_curr->removed) {
+		list_del_rcu(&node_curr->mac_list);
+		node_curr->removed = true;
+		kfree_rcu(node_curr, rcu_head);
+	}
+	spin_unlock_bh(&hsr->list_lock);
+
+done:
+	/* Push back here */
+	skb_push(skb, total_pull_size);
+}
+
+/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
+ *
+ * If the frame was sent by a node's B interface, replace the source
+ * address with that node's "official" address (macaddress_A) so that upper
+ * layers recognize where it came from.
+ */
+void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
+{
+	if (!skb_mac_header_was_set(skb)) {
+		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
+		return;
+	}
+
+	memcpy(&eth_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
+}
+
+/* 'skb' is a frame meant for another host.
+ * 'port' is the outgoing interface
+ *
+ * Substitute the target (dest) MAC address if necessary, so the it matches the
+ * recipient interface MAC address, regardless of whether that is the
+ * recipient's A or B interface.
+ * This is needed to keep the packets flowing through switches that learn on
+ * which "side" the different interfaces are.
+ */
+void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
+			 struct hsr_port *port)
+{
+	struct hsr_node *node_dst;
+
+	if (!skb_mac_header_was_set(skb)) {
+		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
+		return;
+	}
+
+	if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
+		return;
+
+	node_dst = find_node_by_addr_A(&port->hsr->node_db,
+				       eth_hdr(skb)->h_dest);
+	if (!node_dst) {
+		if (port->hsr->prot_version != PRP_V1 && net_ratelimit())
+			netdev_err(skb->dev, "%s: Unknown node\n", __func__);
+		return;
+	}
+	if (port->type != node_dst->addr_B_port)
+		return;
+
+	if (is_valid_ether_addr(node_dst->macaddress_B))
+		ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
+}
+
+void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
+			   u16 sequence_nr)
+{
+	/* Don't register incoming frames without a valid sequence number. This
+	 * ensures entries of restarted nodes gets pruned so that they can
+	 * re-register and resume communications.
+	 */
+	if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
+	    seq_nr_before(sequence_nr, node->seq_out[port->type]))
+		return;
+
+	node->time_in[port->type] = jiffies;
+	node->time_in_stale[port->type] = false;
+}
+
+/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
+ * ethhdr->h_source address and skb->mac_header set.
+ *
+ * Return:
+ *	 1 if frame can be shown to have been sent recently on this interface,
+ *	 0 otherwise, or
+ *	 negative error code on error
+ */
+int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
+			   u16 sequence_nr)
+{
+	spin_lock_bh(&node->seq_out_lock);
+	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
+	    time_is_after_jiffies(node->time_out[port->type] +
+	    msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) {
+		spin_unlock_bh(&node->seq_out_lock);
+		return 1;
+	}
+
+	node->time_out[port->type] = jiffies;
+	node->seq_out[port->type] = sequence_nr;
+	spin_unlock_bh(&node->seq_out_lock);
+	return 0;
+}
+
+static struct hsr_port *get_late_port(struct hsr_priv *hsr,
+				      struct hsr_node *node)
+{
+	if (node->time_in_stale[HSR_PT_SLAVE_A])
+		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (node->time_in_stale[HSR_PT_SLAVE_B])
+		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+
+	if (time_after(node->time_in[HSR_PT_SLAVE_B],
+		       node->time_in[HSR_PT_SLAVE_A] +
+					msecs_to_jiffies(MAX_SLAVE_DIFF)))
+		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (time_after(node->time_in[HSR_PT_SLAVE_A],
+		       node->time_in[HSR_PT_SLAVE_B] +
+					msecs_to_jiffies(MAX_SLAVE_DIFF)))
+		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+
+	return NULL;
+}
+
+/* Remove stale sequence_nr records. Called by timer every
+ * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
+ */
+void hsr_prune_nodes(struct timer_list *t)
+{
+	struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
+	struct hsr_node *node;
+	struct hsr_node *tmp;
+	struct hsr_port *port;
+	unsigned long timestamp;
+	unsigned long time_a, time_b;
+
+	spin_lock_bh(&hsr->list_lock);
+	list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
+		/* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
+		 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
+		 * the master port. Thus the master node will be repeatedly
+		 * pruned leading to packet loss.
+		 */
+		if (hsr_addr_is_self(hsr, node->macaddress_A))
+			continue;
+
+		/* Shorthand */
+		time_a = node->time_in[HSR_PT_SLAVE_A];
+		time_b = node->time_in[HSR_PT_SLAVE_B];
+
+		/* Check for timestamps old enough to risk wrap-around */
+		if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
+			node->time_in_stale[HSR_PT_SLAVE_A] = true;
+		if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
+			node->time_in_stale[HSR_PT_SLAVE_B] = true;
+
+		/* Get age of newest frame from node.
+		 * At least one time_in is OK here; nodes get pruned long
+		 * before both time_ins can get stale
+		 */
+		timestamp = time_a;
+		if (node->time_in_stale[HSR_PT_SLAVE_A] ||
+		    (!node->time_in_stale[HSR_PT_SLAVE_B] &&
+		    time_after(time_b, time_a)))
+			timestamp = time_b;
+
+		/* Warn of ring error only as long as we get frames at all */
+		if (time_is_after_jiffies(timestamp +
+				msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
+			rcu_read_lock();
+			port = get_late_port(hsr, node);
+			if (port)
+				hsr_nl_ringerror(hsr, node->macaddress_A, port);
+			rcu_read_unlock();
+		}
+
+		/* Prune old entries */
+		if (time_is_before_jiffies(timestamp +
+				msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
+			hsr_nl_nodedown(hsr, node->macaddress_A);
+			if (!node->removed) {
+				list_del_rcu(&node->mac_list);
+				node->removed = true;
+				/* Note that we need to free this entry later: */
+				kfree_rcu(node, rcu_head);
+			}
+		}
+	}
+	spin_unlock_bh(&hsr->list_lock);
+
+	/* Restart timer */
+	mod_timer(&hsr->prune_timer,
+		  jiffies + msecs_to_jiffies(PRUNE_PERIOD));
+}
+
+void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
+			unsigned char addr[ETH_ALEN])
+{
+	struct hsr_node *node;
+
+	if (!_pos) {
+		node = list_first_or_null_rcu(&hsr->node_db,
+					      struct hsr_node, mac_list);
+		if (node)
+			ether_addr_copy(addr, node->macaddress_A);
+		return node;
+	}
+
+	node = _pos;
+	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
+		ether_addr_copy(addr, node->macaddress_A);
+		return node;
+	}
+
+	return NULL;
+}
+
+int hsr_get_node_data(struct hsr_priv *hsr,
+		      const unsigned char *addr,
+		      unsigned char addr_b[ETH_ALEN],
+		      unsigned int *addr_b_ifindex,
+		      int *if1_age,
+		      u16 *if1_seq,
+		      int *if2_age,
+		      u16 *if2_seq)
+{
+	struct hsr_node *node;
+	struct hsr_port *port;
+	unsigned long tdiff;
+
+	node = find_node_by_addr_A(&hsr->node_db, addr);
+	if (!node)
+		return -ENOENT;
+
+	ether_addr_copy(addr_b, node->macaddress_B);
+
+	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
+	if (node->time_in_stale[HSR_PT_SLAVE_A])
+		*if1_age = INT_MAX;
+#if HZ <= MSEC_PER_SEC
+	else if (tdiff > msecs_to_jiffies(INT_MAX))
+		*if1_age = INT_MAX;
+#endif
+	else
+		*if1_age = jiffies_to_msecs(tdiff);
+
+	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
+	if (node->time_in_stale[HSR_PT_SLAVE_B])
+		*if2_age = INT_MAX;
+#if HZ <= MSEC_PER_SEC
+	else if (tdiff > msecs_to_jiffies(INT_MAX))
+		*if2_age = INT_MAX;
+#endif
+	else
+		*if2_age = jiffies_to_msecs(tdiff);
+
+	/* Present sequence numbers as if they were incoming on interface */
+	*if1_seq = node->seq_out[HSR_PT_SLAVE_B];
+	*if2_seq = node->seq_out[HSR_PT_SLAVE_A];
+
+	if (node->addr_B_port != HSR_PT_NONE) {
+		port = hsr_port_get_hsr(hsr, node->addr_B_port);
+		*addr_b_ifindex = port->dev->ifindex;
+	} else {
+		*addr_b_ifindex = -1;
+	}
+
+	return 0;
+}
diff --git a/net/hsr/hsr_framereg.h b/net/hsr/hsr_framereg.h
new file mode 100644
index 000000000..b23556251
--- /dev/null
+++ b/net/hsr/hsr_framereg.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
+ */
+
+#ifndef __HSR_FRAMEREG_H
+#define __HSR_FRAMEREG_H
+
+#include "hsr_main.h"
+
+struct hsr_node;
+
+struct hsr_frame_info {
+	struct sk_buff *skb_std;
+	struct sk_buff *skb_hsr;
+	struct sk_buff *skb_prp;
+	struct hsr_port *port_rcv;
+	struct hsr_node *node_src;
+	u16 sequence_nr;
+	bool is_supervision;
+	bool is_vlan;
+	bool is_local_dest;
+	bool is_local_exclusive;
+	bool is_from_san;
+};
+
+void hsr_del_self_node(struct hsr_priv *hsr);
+void hsr_del_nodes(struct list_head *node_db);
+struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
+			      struct sk_buff *skb, bool is_sup,
+			      enum hsr_port_type rx_port);
+void hsr_handle_sup_frame(struct hsr_frame_info *frame);
+bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr);
+
+void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb);
+void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
+			 struct hsr_port *port);
+
+void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
+			   u16 sequence_nr);
+int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
+			   u16 sequence_nr);
+
+void hsr_prune_nodes(struct timer_list *t);
+
+int hsr_create_self_node(struct hsr_priv *hsr,
+			 const unsigned char addr_a[ETH_ALEN],
+			 const unsigned char addr_b[ETH_ALEN]);
+
+void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
+			unsigned char addr[ETH_ALEN]);
+
+int hsr_get_node_data(struct hsr_priv *hsr,
+		      const unsigned char *addr,
+		      unsigned char addr_b[ETH_ALEN],
+		      unsigned int *addr_b_ifindex,
+		      int *if1_age,
+		      u16 *if1_seq,
+		      int *if2_age,
+		      u16 *if2_seq);
+
+void prp_handle_san_frame(bool san, enum hsr_port_type port,
+			  struct hsr_node *node);
+void prp_update_san_info(struct hsr_node *node, bool is_sup);
+
+struct hsr_node {
+	struct list_head	mac_list;
+	/* Protect R/W access to seq_out */
+	spinlock_t		seq_out_lock;
+	unsigned char		macaddress_A[ETH_ALEN];
+	unsigned char		macaddress_B[ETH_ALEN];
+	/* Local slave through which AddrB frames are received from this node */
+	enum hsr_port_type	addr_B_port;
+	unsigned long		time_in[HSR_PT_PORTS];
+	bool			time_in_stale[HSR_PT_PORTS];
+	unsigned long		time_out[HSR_PT_PORTS];
+	/* if the node is a SAN */
+	bool			san_a;
+	bool			san_b;
+	u16			seq_out[HSR_PT_PORTS];
+	bool			removed;
+	struct rcu_head		rcu_head;
+};
+
+#endif /* __HSR_FRAMEREG_H */
diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
new file mode 100644
index 000000000..b099c3150
--- /dev/null
+++ b/net/hsr/hsr_main.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * Event handling for HSR and PRP devices.
+ */
+
+#include <linux/netdevice.h>
+#include <net/rtnetlink.h>
+#include <linux/rculist.h>
+#include <linux/timer.h>
+#include <linux/etherdevice.h>
+#include "hsr_main.h"
+#include "hsr_device.h"
+#include "hsr_netlink.h"
+#include "hsr_framereg.h"
+#include "hsr_slave.h"
+
+static bool hsr_slave_empty(struct hsr_priv *hsr)
+{
+	struct hsr_port *port;
+
+	hsr_for_each_port(hsr, port)
+		if (port->type != HSR_PT_MASTER)
+			return false;
+	return true;
+}
+
+static int hsr_netdev_notify(struct notifier_block *nb, unsigned long event,
+			     void *ptr)
+{
+	struct hsr_port *port, *master;
+	struct net_device *dev;
+	struct hsr_priv *hsr;
+	LIST_HEAD(list_kill);
+	int mtu_max;
+	int res;
+
+	dev = netdev_notifier_info_to_dev(ptr);
+	port = hsr_port_get_rtnl(dev);
+	if (!port) {
+		if (!is_hsr_master(dev))
+			return NOTIFY_DONE;	/* Not an HSR device */
+		hsr = netdev_priv(dev);
+		port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+		if (!port) {
+			/* Resend of notification concerning removed device? */
+			return NOTIFY_DONE;
+		}
+	} else {
+		hsr = port->hsr;
+	}
+
+	switch (event) {
+	case NETDEV_UP:		/* Administrative state DOWN */
+	case NETDEV_DOWN:	/* Administrative state UP */
+	case NETDEV_CHANGE:	/* Link (carrier) state changes */
+		hsr_check_carrier_and_operstate(hsr);
+		break;
+	case NETDEV_CHANGENAME:
+		if (is_hsr_master(dev))
+			hsr_debugfs_rename(dev);
+		break;
+	case NETDEV_CHANGEADDR:
+		if (port->type == HSR_PT_MASTER) {
+			/* This should not happen since there's no
+			 * ndo_set_mac_address() for HSR devices - i.e. not
+			 * supported.
+			 */
+			break;
+		}
+
+		master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+
+		if (port->type == HSR_PT_SLAVE_A) {
+			eth_hw_addr_set(master->dev, dev->dev_addr);
+			call_netdevice_notifiers(NETDEV_CHANGEADDR,
+						 master->dev);
+		}
+
+		/* Make sure we recognize frames from ourselves in hsr_rcv() */
+		port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+		res = hsr_create_self_node(hsr,
+					   master->dev->dev_addr,
+					   port ?
+						port->dev->dev_addr :
+						master->dev->dev_addr);
+		if (res)
+			netdev_warn(master->dev,
+				    "Could not update HSR node address.\n");
+		break;
+	case NETDEV_CHANGEMTU:
+		if (port->type == HSR_PT_MASTER)
+			break; /* Handled in ndo_change_mtu() */
+		mtu_max = hsr_get_max_mtu(port->hsr);
+		master = hsr_port_get_hsr(port->hsr, HSR_PT_MASTER);
+		master->dev->mtu = mtu_max;
+		break;
+	case NETDEV_UNREGISTER:
+		if (!is_hsr_master(dev)) {
+			master = hsr_port_get_hsr(port->hsr, HSR_PT_MASTER);
+			hsr_del_port(port);
+			if (hsr_slave_empty(master->hsr)) {
+				const struct rtnl_link_ops *ops;
+
+				ops = master->dev->rtnl_link_ops;
+				ops->dellink(master->dev, &list_kill);
+				unregister_netdevice_many(&list_kill);
+			}
+		}
+		break;
+	case NETDEV_PRE_TYPE_CHANGE:
+		/* HSR works only on Ethernet devices. Refuse slave to change
+		 * its type.
+		 */
+		return NOTIFY_BAD;
+	}
+
+	return NOTIFY_DONE;
+}
+
+struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt)
+{
+	struct hsr_port *port;
+
+	hsr_for_each_port(hsr, port)
+		if (port->type == pt)
+			return port;
+	return NULL;
+}
+
+int hsr_get_version(struct net_device *dev, enum hsr_version *ver)
+{
+	struct hsr_priv *hsr;
+
+	hsr = netdev_priv(dev);
+	*ver = hsr->prot_version;
+
+	return 0;
+}
+EXPORT_SYMBOL(hsr_get_version);
+
+static struct notifier_block hsr_nb = {
+	.notifier_call = hsr_netdev_notify,	/* Slave event notifications */
+};
+
+static int __init hsr_init(void)
+{
+	int res;
+
+	BUILD_BUG_ON(sizeof(struct hsr_tag) != HSR_HLEN);
+
+	register_netdevice_notifier(&hsr_nb);
+	res = hsr_netlink_init();
+
+	return res;
+}
+
+static void __exit hsr_exit(void)
+{
+	hsr_netlink_exit();
+	hsr_debugfs_remove_root();
+	unregister_netdevice_notifier(&hsr_nb);
+}
+
+module_init(hsr_init);
+module_exit(hsr_exit);
+MODULE_LICENSE("GPL");
diff --git a/net/hsr/hsr_main.h b/net/hsr/hsr_main.h
new file mode 100644
index 000000000..18e01791a
--- /dev/null
+++ b/net/hsr/hsr_main.h
@@ -0,0 +1,294 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
+ */
+
+#ifndef __HSR_PRIVATE_H
+#define __HSR_PRIVATE_H
+
+#include <linux/netdevice.h>
+#include <linux/list.h>
+#include <linux/if_vlan.h>
+#include <linux/if_hsr.h>
+
+/* Time constants as specified in the HSR specification (IEC-62439-3 2010)
+ * Table 8.
+ * All values in milliseconds.
+ */
+#define HSR_LIFE_CHECK_INTERVAL		 2000 /* ms */
+#define HSR_NODE_FORGET_TIME		60000 /* ms */
+#define HSR_ANNOUNCE_INTERVAL		  100 /* ms */
+#define HSR_ENTRY_FORGET_TIME		  400 /* ms */
+
+/* By how much may slave1 and slave2 timestamps of latest received frame from
+ * each node differ before we notify of communication problem?
+ */
+#define MAX_SLAVE_DIFF			 3000 /* ms */
+#define HSR_SEQNR_START			(USHRT_MAX - 1024)
+#define HSR_SUP_SEQNR_START		(HSR_SEQNR_START / 2)
+
+/* How often shall we check for broken ring and remove node entries older than
+ * HSR_NODE_FORGET_TIME?
+ */
+#define PRUNE_PERIOD			 3000 /* ms */
+#define HSR_TLV_EOT				   0  /* End of TLVs */
+#define HSR_TLV_ANNOUNCE		   22
+#define HSR_TLV_LIFE_CHECK		   23
+/* PRP V1 life check for Duplicate discard */
+#define PRP_TLV_LIFE_CHECK_DD		   20
+/* PRP V1 life check for Duplicate Accept */
+#define PRP_TLV_LIFE_CHECK_DA		   21
+/* PRP V1 life redundancy box MAC address */
+#define PRP_TLV_REDBOX_MAC		   30
+
+#define HSR_V1_SUP_LSDUSIZE		52
+
+/* The helper functions below assumes that 'path' occupies the 4 most
+ * significant bits of the 16-bit field shared by 'path' and 'LSDU_size' (or
+ * equivalently, the 4 most significant bits of HSR tag byte 14).
+ *
+ * This is unclear in the IEC specification; its definition of MAC addresses
+ * indicates the spec is written with the least significant bit first (to the
+ * left). This, however, would mean that the LSDU field would be split in two
+ * with the path field in-between, which seems strange. I'm guessing the MAC
+ * address definition is in error.
+ */
+
+static inline void set_hsr_tag_path(struct hsr_tag *ht, u16 path)
+{
+	ht->path_and_LSDU_size =
+		htons((ntohs(ht->path_and_LSDU_size) & 0x0FFF) | (path << 12));
+}
+
+static inline void set_hsr_tag_LSDU_size(struct hsr_tag *ht, u16 LSDU_size)
+{
+	ht->path_and_LSDU_size = htons((ntohs(ht->path_and_LSDU_size) &
+				       0xF000) | (LSDU_size & 0x0FFF));
+}
+
+struct hsr_ethhdr {
+	struct ethhdr	ethhdr;
+	struct hsr_tag	hsr_tag;
+} __packed;
+
+struct hsr_vlan_ethhdr {
+	struct vlan_ethhdr vlanhdr;
+	struct hsr_tag	hsr_tag;
+} __packed;
+
+struct hsr_sup_tlv {
+	u8		HSR_TLV_type;
+	u8		HSR_TLV_length;
+} __packed;
+
+/* HSR/PRP Supervision Frame data types.
+ * Field names as defined in the IEC:2010 standard for HSR.
+ */
+struct hsr_sup_tag {
+	__be16				path_and_HSR_ver;
+	__be16				sequence_nr;
+	struct hsr_sup_tlv  tlv;
+} __packed;
+
+struct hsr_sup_payload {
+	unsigned char	macaddress_A[ETH_ALEN];
+} __packed;
+
+static inline void set_hsr_stag_path(struct hsr_sup_tag *hst, u16 path)
+{
+	set_hsr_tag_path((struct hsr_tag *)hst, path);
+}
+
+static inline void set_hsr_stag_HSR_ver(struct hsr_sup_tag *hst, u16 HSR_ver)
+{
+	set_hsr_tag_LSDU_size((struct hsr_tag *)hst, HSR_ver);
+}
+
+struct hsrv0_ethhdr_sp {
+	struct ethhdr		ethhdr;
+	struct hsr_sup_tag	hsr_sup;
+} __packed;
+
+struct hsrv1_ethhdr_sp {
+	struct ethhdr		ethhdr;
+	struct hsr_tag		hsr;
+	struct hsr_sup_tag	hsr_sup;
+} __packed;
+
+enum hsr_port_type {
+	HSR_PT_NONE = 0,	/* Must be 0, used by framereg */
+	HSR_PT_SLAVE_A,
+	HSR_PT_SLAVE_B,
+	HSR_PT_INTERLINK,
+	HSR_PT_MASTER,
+	HSR_PT_PORTS,	/* This must be the last item in the enum */
+};
+
+/* PRP Redunancy Control Trailor (RCT).
+ * As defined in IEC-62439-4:2012, the PRP RCT is really { sequence Nr,
+ * Lan indentifier (LanId), LSDU_size and PRP_suffix = 0x88FB }.
+ *
+ * Field names as defined in the IEC:2012 standard for PRP.
+ */
+struct prp_rct {
+	__be16          sequence_nr;
+	__be16          lan_id_and_LSDU_size;
+	__be16          PRP_suffix;
+} __packed;
+
+static inline u16 get_prp_LSDU_size(struct prp_rct *rct)
+{
+	return ntohs(rct->lan_id_and_LSDU_size) & 0x0FFF;
+}
+
+static inline void set_prp_lan_id(struct prp_rct *rct, u16 lan_id)
+{
+	rct->lan_id_and_LSDU_size = htons((ntohs(rct->lan_id_and_LSDU_size) &
+					  0x0FFF) | (lan_id << 12));
+}
+static inline void set_prp_LSDU_size(struct prp_rct *rct, u16 LSDU_size)
+{
+	rct->lan_id_and_LSDU_size = htons((ntohs(rct->lan_id_and_LSDU_size) &
+					  0xF000) | (LSDU_size & 0x0FFF));
+}
+
+struct hsr_port {
+	struct list_head	port_list;
+	struct net_device	*dev;
+	struct hsr_priv		*hsr;
+	enum hsr_port_type	type;
+};
+
+struct hsr_frame_info;
+struct hsr_node;
+
+struct hsr_proto_ops {
+	/* format and send supervision frame */
+	void (*send_sv_frame)(struct hsr_port *port, unsigned long *interval);
+	void (*handle_san_frame)(bool san, enum hsr_port_type port,
+				 struct hsr_node *node);
+	bool (*drop_frame)(struct hsr_frame_info *frame, struct hsr_port *port);
+	struct sk_buff * (*get_untagged_frame)(struct hsr_frame_info *frame,
+					       struct hsr_port *port);
+	struct sk_buff * (*create_tagged_frame)(struct hsr_frame_info *frame,
+						struct hsr_port *port);
+	int (*fill_frame_info)(__be16 proto, struct sk_buff *skb,
+			       struct hsr_frame_info *frame);
+	bool (*invalid_dan_ingress_frame)(__be16 protocol);
+	void (*update_san_info)(struct hsr_node *node, bool is_sup);
+};
+
+struct hsr_self_node {
+	unsigned char	macaddress_A[ETH_ALEN];
+	unsigned char	macaddress_B[ETH_ALEN];
+	struct rcu_head	rcu_head;
+};
+
+struct hsr_priv {
+	struct rcu_head		rcu_head;
+	struct list_head	ports;
+	struct list_head	node_db;	/* Known HSR nodes */
+	struct hsr_self_node	__rcu *self_node;	/* MACs of slaves */
+	struct timer_list	announce_timer;	/* Supervision frame dispatch */
+	struct timer_list	prune_timer;
+	int announce_count;
+	u16 sequence_nr;
+	u16 sup_sequence_nr;	/* For HSRv1 separate seq_nr for supervision */
+	enum hsr_version prot_version;	/* Indicate if HSRv0, HSRv1 or PRPv1 */
+	spinlock_t seqnr_lock;	/* locking for sequence_nr */
+	spinlock_t list_lock;	/* locking for node list */
+	struct hsr_proto_ops	*proto_ops;
+#define PRP_LAN_ID	0x5     /* 0x1010 for A and 0x1011 for B. Bit 0 is set
+				 * based on SLAVE_A or SLAVE_B
+				 */
+	u8 net_id;		/* for PRP, it occupies most significant 3 bits
+				 * of lan_id
+				 */
+	bool fwd_offloaded;	/* Forwarding offloaded to HW */
+	unsigned char		sup_multicast_addr[ETH_ALEN] __aligned(sizeof(u16));
+				/* Align to u16 boundary to avoid unaligned access
+				 * in ether_addr_equal
+				 */
+#ifdef	CONFIG_DEBUG_FS
+	struct dentry *node_tbl_root;
+#endif
+};
+
+#define hsr_for_each_port(hsr, port) \
+	list_for_each_entry_rcu((port), &(hsr)->ports, port_list)
+
+struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt);
+
+/* Caller must ensure skb is a valid HSR frame */
+static inline u16 hsr_get_skb_sequence_nr(struct sk_buff *skb)
+{
+	struct hsr_ethhdr *hsr_ethhdr;
+
+	hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
+	return ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
+}
+
+static inline struct prp_rct *skb_get_PRP_rct(struct sk_buff *skb)
+{
+	unsigned char *tail = skb_tail_pointer(skb) - HSR_HLEN;
+
+	struct prp_rct *rct = (struct prp_rct *)tail;
+
+	if (rct->PRP_suffix == htons(ETH_P_PRP))
+		return rct;
+
+	return NULL;
+}
+
+/* Assume caller has confirmed this skb is PRP suffixed */
+static inline u16 prp_get_skb_sequence_nr(struct prp_rct *rct)
+{
+	return ntohs(rct->sequence_nr);
+}
+
+/* assume there is a valid rct */
+static inline bool prp_check_lsdu_size(struct sk_buff *skb,
+				       struct prp_rct *rct,
+				       bool is_sup)
+{
+	struct ethhdr *ethhdr;
+	int expected_lsdu_size;
+
+	if (is_sup) {
+		expected_lsdu_size = HSR_V1_SUP_LSDUSIZE;
+	} else {
+		ethhdr = (struct ethhdr *)skb_mac_header(skb);
+		expected_lsdu_size = skb->len - 14;
+		if (ethhdr->h_proto == htons(ETH_P_8021Q))
+			expected_lsdu_size -= 4;
+	}
+
+	return (expected_lsdu_size == get_prp_LSDU_size(rct));
+}
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+void hsr_debugfs_rename(struct net_device *dev);
+void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev);
+void hsr_debugfs_term(struct hsr_priv *priv);
+void hsr_debugfs_create_root(void);
+void hsr_debugfs_remove_root(void);
+#else
+static inline void hsr_debugfs_rename(struct net_device *dev)
+{
+}
+static inline void hsr_debugfs_init(struct hsr_priv *priv,
+				    struct net_device *hsr_dev)
+{}
+static inline void hsr_debugfs_term(struct hsr_priv *priv)
+{}
+static inline void hsr_debugfs_create_root(void)
+{}
+static inline void hsr_debugfs_remove_root(void)
+{}
+#endif
+
+#endif /*  __HSR_PRIVATE_H */
diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
new file mode 100644
index 000000000..78fe40eb9
--- /dev/null
+++ b/net/hsr/hsr_netlink.c
@@ -0,0 +1,556 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * Routines for handling Netlink messages for HSR and PRP.
+ */
+
+#include "hsr_netlink.h"
+#include <linux/kernel.h>
+#include <net/rtnetlink.h>
+#include <net/genetlink.h>
+#include "hsr_main.h"
+#include "hsr_device.h"
+#include "hsr_framereg.h"
+
+static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
+	[IFLA_HSR_SLAVE1]		= { .type = NLA_U32 },
+	[IFLA_HSR_SLAVE2]		= { .type = NLA_U32 },
+	[IFLA_HSR_MULTICAST_SPEC]	= { .type = NLA_U8 },
+	[IFLA_HSR_VERSION]	= { .type = NLA_U8 },
+	[IFLA_HSR_SUPERVISION_ADDR]	= { .len = ETH_ALEN },
+	[IFLA_HSR_SEQ_NR]		= { .type = NLA_U16 },
+	[IFLA_HSR_PROTOCOL]		= { .type = NLA_U8 },
+};
+
+/* Here, it seems a netdevice has already been allocated for us, and the
+ * hsr_dev_setup routine has been executed. Nice!
+ */
+static int hsr_newlink(struct net *src_net, struct net_device *dev,
+		       struct nlattr *tb[], struct nlattr *data[],
+		       struct netlink_ext_ack *extack)
+{
+	enum hsr_version proto_version;
+	unsigned char multicast_spec;
+	u8 proto = HSR_PROTOCOL_HSR;
+	struct net_device *link[2];
+
+	if (!data) {
+		NL_SET_ERR_MSG_MOD(extack, "No slave devices specified");
+		return -EINVAL;
+	}
+	if (!data[IFLA_HSR_SLAVE1]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave1 device not specified");
+		return -EINVAL;
+	}
+	link[0] = __dev_get_by_index(src_net,
+				     nla_get_u32(data[IFLA_HSR_SLAVE1]));
+	if (!link[0]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave1 does not exist");
+		return -EINVAL;
+	}
+	if (!data[IFLA_HSR_SLAVE2]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave2 device not specified");
+		return -EINVAL;
+	}
+	link[1] = __dev_get_by_index(src_net,
+				     nla_get_u32(data[IFLA_HSR_SLAVE2]));
+	if (!link[1]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave2 does not exist");
+		return -EINVAL;
+	}
+
+	if (link[0] == link[1]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave1 and Slave2 are same");
+		return -EINVAL;
+	}
+
+	if (!data[IFLA_HSR_MULTICAST_SPEC])
+		multicast_spec = 0;
+	else
+		multicast_spec = nla_get_u8(data[IFLA_HSR_MULTICAST_SPEC]);
+
+	if (data[IFLA_HSR_PROTOCOL])
+		proto = nla_get_u8(data[IFLA_HSR_PROTOCOL]);
+
+	if (proto >= HSR_PROTOCOL_MAX) {
+		NL_SET_ERR_MSG_MOD(extack, "Unsupported protocol");
+		return -EINVAL;
+	}
+
+	if (!data[IFLA_HSR_VERSION]) {
+		proto_version = HSR_V0;
+	} else {
+		if (proto == HSR_PROTOCOL_PRP) {
+			NL_SET_ERR_MSG_MOD(extack, "PRP version unsupported");
+			return -EINVAL;
+		}
+
+		proto_version = nla_get_u8(data[IFLA_HSR_VERSION]);
+		if (proto_version > HSR_V1) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Only HSR version 0/1 supported");
+			return -EINVAL;
+		}
+	}
+
+	if (proto == HSR_PROTOCOL_PRP)
+		proto_version = PRP_V1;
+
+	return hsr_dev_finalize(dev, link, multicast_spec, proto_version, extack);
+}
+
+static void hsr_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct hsr_priv *hsr = netdev_priv(dev);
+
+	del_timer_sync(&hsr->prune_timer);
+	del_timer_sync(&hsr->announce_timer);
+
+	hsr_debugfs_term(hsr);
+	hsr_del_ports(hsr);
+
+	hsr_del_self_node(hsr);
+	hsr_del_nodes(&hsr->node_db);
+
+	unregister_netdevice_queue(dev, head);
+}
+
+static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct hsr_priv *hsr = netdev_priv(dev);
+	u8 proto = HSR_PROTOCOL_HSR;
+	struct hsr_port *port;
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (port) {
+		if (nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex))
+			goto nla_put_failure;
+	}
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+	if (port) {
+		if (nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex))
+			goto nla_put_failure;
+	}
+
+	if (nla_put(skb, IFLA_HSR_SUPERVISION_ADDR, ETH_ALEN,
+		    hsr->sup_multicast_addr) ||
+	    nla_put_u16(skb, IFLA_HSR_SEQ_NR, hsr->sequence_nr))
+		goto nla_put_failure;
+	if (hsr->prot_version == PRP_V1)
+		proto = HSR_PROTOCOL_PRP;
+	if (nla_put_u8(skb, IFLA_HSR_PROTOCOL, proto))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static struct rtnl_link_ops hsr_link_ops __read_mostly = {
+	.kind		= "hsr",
+	.maxtype	= IFLA_HSR_MAX,
+	.policy		= hsr_policy,
+	.priv_size	= sizeof(struct hsr_priv),
+	.setup		= hsr_dev_setup,
+	.newlink	= hsr_newlink,
+	.dellink	= hsr_dellink,
+	.fill_info	= hsr_fill_info,
+};
+
+/* attribute policy */
+static const struct nla_policy hsr_genl_policy[HSR_A_MAX + 1] = {
+	[HSR_A_NODE_ADDR] = { .len = ETH_ALEN },
+	[HSR_A_NODE_ADDR_B] = { .len = ETH_ALEN },
+	[HSR_A_IFINDEX] = { .type = NLA_U32 },
+	[HSR_A_IF1_AGE] = { .type = NLA_U32 },
+	[HSR_A_IF2_AGE] = { .type = NLA_U32 },
+	[HSR_A_IF1_SEQ] = { .type = NLA_U16 },
+	[HSR_A_IF2_SEQ] = { .type = NLA_U16 },
+};
+
+static struct genl_family hsr_genl_family;
+
+static const struct genl_multicast_group hsr_mcgrps[] = {
+	{ .name = "hsr-network", },
+};
+
+/* This is called if for some node with MAC address addr, we only get frames
+ * over one of the slave interfaces. This would indicate an open network ring
+ * (i.e. a link has failed somewhere).
+ */
+void hsr_nl_ringerror(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN],
+		      struct hsr_port *port)
+{
+	struct sk_buff *skb;
+	void *msg_head;
+	struct hsr_port *master;
+	int res;
+
+	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb)
+		goto fail;
+
+	msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0,
+			       HSR_C_RING_ERROR);
+	if (!msg_head)
+		goto nla_put_failure;
+
+	res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
+	if (res < 0)
+		goto nla_put_failure;
+
+	res = nla_put_u32(skb, HSR_A_IFINDEX, port->dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb, msg_head);
+	genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
+
+	return;
+
+nla_put_failure:
+	kfree_skb(skb);
+
+fail:
+	rcu_read_lock();
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	netdev_warn(master->dev, "Could not send HSR ring error message\n");
+	rcu_read_unlock();
+}
+
+/* This is called when we haven't heard from the node with MAC address addr for
+ * some time (just before the node is removed from the node table/list).
+ */
+void hsr_nl_nodedown(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN])
+{
+	struct sk_buff *skb;
+	void *msg_head;
+	struct hsr_port *master;
+	int res;
+
+	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb)
+		goto fail;
+
+	msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0, HSR_C_NODE_DOWN);
+	if (!msg_head)
+		goto nla_put_failure;
+
+	res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
+	if (res < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb, msg_head);
+	genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
+
+	return;
+
+nla_put_failure:
+	kfree_skb(skb);
+
+fail:
+	rcu_read_lock();
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	netdev_warn(master->dev, "Could not send HSR node down\n");
+	rcu_read_unlock();
+}
+
+/* HSR_C_GET_NODE_STATUS lets userspace query the internal HSR node table
+ * about the status of a specific node in the network, defined by its MAC
+ * address.
+ *
+ * Input: hsr ifindex, node mac address
+ * Output: hsr ifindex, node mac address (copied from request),
+ *	   age of latest frame from node over slave 1, slave 2 [ms]
+ */
+static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info)
+{
+	/* For receiving */
+	struct nlattr *na;
+	struct net_device *hsr_dev;
+
+	/* For sending */
+	struct sk_buff *skb_out;
+	void *msg_head;
+	struct hsr_priv *hsr;
+	struct hsr_port *port;
+	unsigned char hsr_node_addr_b[ETH_ALEN];
+	int hsr_node_if1_age;
+	u16 hsr_node_if1_seq;
+	int hsr_node_if2_age;
+	u16 hsr_node_if2_seq;
+	int addr_b_ifindex;
+	int res;
+
+	if (!info)
+		goto invalid;
+
+	na = info->attrs[HSR_A_IFINDEX];
+	if (!na)
+		goto invalid;
+	na = info->attrs[HSR_A_NODE_ADDR];
+	if (!na)
+		goto invalid;
+
+	rcu_read_lock();
+	hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
+				       nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+	if (!hsr_dev)
+		goto rcu_unlock;
+	if (!is_hsr_master(hsr_dev))
+		goto rcu_unlock;
+
+	/* Send reply */
+	skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb_out) {
+		res = -ENOMEM;
+		goto fail;
+	}
+
+	msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
+			       info->snd_seq, &hsr_genl_family, 0,
+			       HSR_C_SET_NODE_STATUS);
+	if (!msg_head) {
+		res = -ENOMEM;
+		goto nla_put_failure;
+	}
+
+	res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	hsr = netdev_priv(hsr_dev);
+	res = hsr_get_node_data(hsr,
+				(unsigned char *)
+				nla_data(info->attrs[HSR_A_NODE_ADDR]),
+					 hsr_node_addr_b,
+					 &addr_b_ifindex,
+					 &hsr_node_if1_age,
+					 &hsr_node_if1_seq,
+					 &hsr_node_if2_age,
+					 &hsr_node_if2_seq);
+	if (res < 0)
+		goto nla_put_failure;
+
+	res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN,
+		      nla_data(info->attrs[HSR_A_NODE_ADDR]));
+	if (res < 0)
+		goto nla_put_failure;
+
+	if (addr_b_ifindex > -1) {
+		res = nla_put(skb_out, HSR_A_NODE_ADDR_B, ETH_ALEN,
+			      hsr_node_addr_b);
+		if (res < 0)
+			goto nla_put_failure;
+
+		res = nla_put_u32(skb_out, HSR_A_ADDR_B_IFINDEX,
+				  addr_b_ifindex);
+		if (res < 0)
+			goto nla_put_failure;
+	}
+
+	res = nla_put_u32(skb_out, HSR_A_IF1_AGE, hsr_node_if1_age);
+	if (res < 0)
+		goto nla_put_failure;
+	res = nla_put_u16(skb_out, HSR_A_IF1_SEQ, hsr_node_if1_seq);
+	if (res < 0)
+		goto nla_put_failure;
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (port)
+		res = nla_put_u32(skb_out, HSR_A_IF1_IFINDEX,
+				  port->dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	res = nla_put_u32(skb_out, HSR_A_IF2_AGE, hsr_node_if2_age);
+	if (res < 0)
+		goto nla_put_failure;
+	res = nla_put_u16(skb_out, HSR_A_IF2_SEQ, hsr_node_if2_seq);
+	if (res < 0)
+		goto nla_put_failure;
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+	if (port)
+		res = nla_put_u32(skb_out, HSR_A_IF2_IFINDEX,
+				  port->dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	rcu_read_unlock();
+
+	genlmsg_end(skb_out, msg_head);
+	genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
+
+	return 0;
+
+rcu_unlock:
+	rcu_read_unlock();
+invalid:
+	netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
+	return 0;
+
+nla_put_failure:
+	kfree_skb(skb_out);
+	/* Fall through */
+
+fail:
+	rcu_read_unlock();
+	return res;
+}
+
+/* Get a list of MacAddressA of all nodes known to this node (including self).
+ */
+static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info)
+{
+	unsigned char addr[ETH_ALEN];
+	struct net_device *hsr_dev;
+	struct sk_buff *skb_out;
+	struct hsr_priv *hsr;
+	bool restart = false;
+	struct nlattr *na;
+	void *pos = NULL;
+	void *msg_head;
+	int res;
+
+	if (!info)
+		goto invalid;
+
+	na = info->attrs[HSR_A_IFINDEX];
+	if (!na)
+		goto invalid;
+
+	rcu_read_lock();
+	hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
+				       nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+	if (!hsr_dev)
+		goto rcu_unlock;
+	if (!is_hsr_master(hsr_dev))
+		goto rcu_unlock;
+
+restart:
+	/* Send reply */
+	skb_out = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+	if (!skb_out) {
+		res = -ENOMEM;
+		goto fail;
+	}
+
+	msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
+			       info->snd_seq, &hsr_genl_family, 0,
+			       HSR_C_SET_NODE_LIST);
+	if (!msg_head) {
+		res = -ENOMEM;
+		goto nla_put_failure;
+	}
+
+	if (!restart) {
+		res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
+		if (res < 0)
+			goto nla_put_failure;
+	}
+
+	hsr = netdev_priv(hsr_dev);
+
+	if (!pos)
+		pos = hsr_get_next_node(hsr, NULL, addr);
+	while (pos) {
+		res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr);
+		if (res < 0) {
+			if (res == -EMSGSIZE) {
+				genlmsg_end(skb_out, msg_head);
+				genlmsg_unicast(genl_info_net(info), skb_out,
+						info->snd_portid);
+				restart = true;
+				goto restart;
+			}
+			goto nla_put_failure;
+		}
+		pos = hsr_get_next_node(hsr, pos, addr);
+	}
+	rcu_read_unlock();
+
+	genlmsg_end(skb_out, msg_head);
+	genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
+
+	return 0;
+
+rcu_unlock:
+	rcu_read_unlock();
+invalid:
+	netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
+	return 0;
+
+nla_put_failure:
+	nlmsg_free(skb_out);
+	/* Fall through */
+
+fail:
+	rcu_read_unlock();
+	return res;
+}
+
+static const struct genl_small_ops hsr_ops[] = {
+	{
+		.cmd = HSR_C_GET_NODE_STATUS,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = 0,
+		.doit = hsr_get_node_status,
+		.dumpit = NULL,
+	},
+	{
+		.cmd = HSR_C_GET_NODE_LIST,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = 0,
+		.doit = hsr_get_node_list,
+		.dumpit = NULL,
+	},
+};
+
+static struct genl_family hsr_genl_family __ro_after_init = {
+	.hdrsize = 0,
+	.name = "HSR",
+	.version = 1,
+	.maxattr = HSR_A_MAX,
+	.policy = hsr_genl_policy,
+	.netnsok = true,
+	.module = THIS_MODULE,
+	.small_ops = hsr_ops,
+	.n_small_ops = ARRAY_SIZE(hsr_ops),
+	.resv_start_op = HSR_C_SET_NODE_LIST + 1,
+	.mcgrps = hsr_mcgrps,
+	.n_mcgrps = ARRAY_SIZE(hsr_mcgrps),
+};
+
+int __init hsr_netlink_init(void)
+{
+	int rc;
+
+	rc = rtnl_link_register(&hsr_link_ops);
+	if (rc)
+		goto fail_rtnl_link_register;
+
+	rc = genl_register_family(&hsr_genl_family);
+	if (rc)
+		goto fail_genl_register_family;
+
+	hsr_debugfs_create_root();
+	return 0;
+
+fail_genl_register_family:
+	rtnl_link_unregister(&hsr_link_ops);
+fail_rtnl_link_register:
+
+	return rc;
+}
+
+void __exit hsr_netlink_exit(void)
+{
+	genl_unregister_family(&hsr_genl_family);
+	rtnl_link_unregister(&hsr_link_ops);
+}
+
+MODULE_ALIAS_RTNL_LINK("hsr");
diff --git a/net/hsr/hsr_netlink.h b/net/hsr/hsr_netlink.h
new file mode 100644
index 000000000..8c99e64e1
--- /dev/null
+++ b/net/hsr/hsr_netlink.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
+ */
+
+#ifndef __HSR_NETLINK_H
+#define __HSR_NETLINK_H
+
+#include <linux/if_ether.h>
+#include <linux/module.h>
+#include <uapi/linux/hsr_netlink.h>
+
+struct hsr_priv;
+struct hsr_port;
+
+int __init hsr_netlink_init(void);
+void __exit hsr_netlink_exit(void);
+
+void hsr_nl_ringerror(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN],
+		      struct hsr_port *port);
+void hsr_nl_nodedown(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN]);
+
+#endif /* __HSR_NETLINK_H */
diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
new file mode 100644
index 000000000..e5742f2a2
--- /dev/null
+++ b/net/hsr/hsr_slave.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * Frame handler other utility functions for HSR and PRP.
+ */
+
+#include "hsr_slave.h"
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_vlan.h>
+#include "hsr_main.h"
+#include "hsr_device.h"
+#include "hsr_forward.h"
+#include "hsr_framereg.h"
+
+bool hsr_invalid_dan_ingress_frame(__be16 protocol)
+{
+	return (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR));
+}
+
+static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
+{
+	struct sk_buff *skb = *pskb;
+	struct hsr_port *port;
+	struct hsr_priv *hsr;
+	__be16 protocol;
+
+	/* Packets from dev_loopback_xmit() do not have L2 header, bail out */
+	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
+		return RX_HANDLER_PASS;
+
+	if (!skb_mac_header_was_set(skb)) {
+		WARN_ONCE(1, "%s: skb invalid", __func__);
+		return RX_HANDLER_PASS;
+	}
+
+	port = hsr_port_get_rcu(skb->dev);
+	if (!port)
+		goto finish_pass;
+	hsr = port->hsr;
+
+	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
+		/* Directly kill frames sent by ourselves */
+		kfree_skb(skb);
+		goto finish_consume;
+	}
+
+	/* For HSR, only tagged frames are expected (unless the device offloads
+	 * HSR tag removal), but for PRP there could be non tagged frames as
+	 * well from Single attached nodes (SANs).
+	 */
+	protocol = eth_hdr(skb)->h_proto;
+
+	if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
+	    hsr->proto_ops->invalid_dan_ingress_frame &&
+	    hsr->proto_ops->invalid_dan_ingress_frame(protocol))
+		goto finish_pass;
+
+	skb_push(skb, ETH_HLEN);
+	skb_reset_mac_header(skb);
+	if ((!hsr->prot_version && protocol == htons(ETH_P_PRP)) ||
+	    protocol == htons(ETH_P_HSR))
+		skb_set_network_header(skb, ETH_HLEN + HSR_HLEN);
+	skb_reset_mac_len(skb);
+
+	hsr_forward_skb(skb, port);
+
+finish_consume:
+	return RX_HANDLER_CONSUMED;
+
+finish_pass:
+	return RX_HANDLER_PASS;
+}
+
+bool hsr_port_exists(const struct net_device *dev)
+{
+	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
+}
+
+static int hsr_check_dev_ok(struct net_device *dev,
+			    struct netlink_ext_ack *extack)
+{
+	/* Don't allow HSR on non-ethernet like devices */
+	if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
+	    dev->addr_len != ETH_ALEN) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
+		return -EINVAL;
+	}
+
+	/* Don't allow enslaving hsr devices */
+	if (is_hsr_master(dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cannot create trees of HSR devices.");
+		return -EINVAL;
+	}
+
+	if (hsr_port_exists(dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "This device is already a HSR slave.");
+		return -EINVAL;
+	}
+
+	if (is_vlan_dev(dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
+		return -EINVAL;
+	}
+
+	if (dev->priv_flags & IFF_DONT_BRIDGE) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "This device does not support bridging.");
+		return -EOPNOTSUPP;
+	}
+
+	/* HSR over bonded devices has not been tested, but I'm not sure it
+	 * won't work...
+	 */
+
+	return 0;
+}
+
+/* Setup device to be added to the HSR bridge. */
+static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
+			     struct hsr_port *port,
+			     struct netlink_ext_ack *extack)
+
+{
+	struct net_device *hsr_dev;
+	struct hsr_port *master;
+	int res;
+
+	/* Don't use promiscuous mode for offload since L2 frame forward
+	 * happens at the offloaded hardware.
+	 */
+	if (!port->hsr->fwd_offloaded) {
+		res = dev_set_promiscuity(dev, 1);
+		if (res)
+			return res;
+	}
+
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	hsr_dev = master->dev;
+
+	res = netdev_upper_dev_link(dev, hsr_dev, extack);
+	if (res)
+		goto fail_upper_dev_link;
+
+	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
+	if (res)
+		goto fail_rx_handler;
+	dev_disable_lro(dev);
+
+	return 0;
+
+fail_rx_handler:
+	netdev_upper_dev_unlink(dev, hsr_dev);
+fail_upper_dev_link:
+	if (!port->hsr->fwd_offloaded)
+		dev_set_promiscuity(dev, -1);
+
+	return res;
+}
+
+int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
+		 enum hsr_port_type type, struct netlink_ext_ack *extack)
+{
+	struct hsr_port *port, *master;
+	int res;
+
+	if (type != HSR_PT_MASTER) {
+		res = hsr_check_dev_ok(dev, extack);
+		if (res)
+			return res;
+	}
+
+	port = hsr_port_get_hsr(hsr, type);
+	if (port)
+		return -EBUSY;	/* This port already exists */
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	port->hsr = hsr;
+	port->dev = dev;
+	port->type = type;
+
+	if (type != HSR_PT_MASTER) {
+		res = hsr_portdev_setup(hsr, dev, port, extack);
+		if (res)
+			goto fail_dev_setup;
+	}
+
+	list_add_tail_rcu(&port->port_list, &hsr->ports);
+	synchronize_rcu();
+
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	netdev_update_features(master->dev);
+	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
+
+	return 0;
+
+fail_dev_setup:
+	kfree(port);
+	return res;
+}
+
+void hsr_del_port(struct hsr_port *port)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *master;
+
+	hsr = port->hsr;
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	list_del_rcu(&port->port_list);
+
+	if (port != master) {
+		netdev_update_features(master->dev);
+		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
+		netdev_rx_handler_unregister(port->dev);
+		dev_set_promiscuity(port->dev, -1);
+		netdev_upper_dev_unlink(port->dev, master->dev);
+	}
+
+	synchronize_rcu();
+
+	kfree(port);
+}
diff --git a/net/hsr/hsr_slave.h b/net/hsr/hsr_slave.h
new file mode 100644
index 000000000..edc4612bb
--- /dev/null
+++ b/net/hsr/hsr_slave.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
+ */
+
+#ifndef __HSR_SLAVE_H
+#define __HSR_SLAVE_H
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include "hsr_main.h"
+
+int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
+		 enum hsr_port_type pt, struct netlink_ext_ack *extack);
+void hsr_del_port(struct hsr_port *port);
+bool hsr_port_exists(const struct net_device *dev);
+
+static inline struct hsr_port *hsr_port_get_rtnl(const struct net_device *dev)
+{
+	ASSERT_RTNL();
+	return hsr_port_exists(dev) ?
+				rtnl_dereference(dev->rx_handler_data) : NULL;
+}
+
+static inline struct hsr_port *hsr_port_get_rcu(const struct net_device *dev)
+{
+	return hsr_port_exists(dev) ?
+				rcu_dereference(dev->rx_handler_data) : NULL;
+}
+
+bool hsr_invalid_dan_ingress_frame(__be16 protocol);
+
+#endif /* __HSR_SLAVE_H */