Initial import

14 files changed, 2576 insertions, 0 deletions

diff --git a/net/hsr/Kconfig b/net/hsr/Kconfig
new file mode 100644
index 000000000..0d3d70905
--- /dev/null
+++ b/net/hsr/Kconfig
@@ -0,0 +1,27 @@
+#
+# IEC 62439-3 High-availability Seamless Redundancy
+#
+
+config HSR
+	tristate "High-availability Seamless Redundancy (HSR)"
+	---help---
+	  If you say Y here, then your Linux box will be able to act as a
+	  DANH ("Doubly attached node implementing HSR"). For this to work,
+	  your Linux box needs (at least) two physical Ethernet interfaces,
+	  and 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.
+
+	  This code is a "best effort" to comply with the HSR standard as
+	  described in IEC 62439-3:2010 (HSRv0), but no compliancy tests have
+	  been made.
+
+	  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..9ae972a82
--- /dev/null
+++ b/net/hsr/Makefile
@@ -0,0 +1,8 @@
+#
+# 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
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
new file mode 100644
index 000000000..44d27469a
--- /dev/null
+++ b/net/hsr/hsr_device.c
@@ -0,0 +1,503 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * This file contains device methods for creating, using and destroying
+ * virtual HSR 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_bh(&dev_base_lock);
+	if (dev->operstate != transition) {
+		dev->operstate = transition;
+		write_unlock_bh(&dev_base_lock);
+		netdev_state_change(dev);
+	} else {
+		write_unlock_bh(&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;
+	bool has_carrier;
+
+	has_carrier = false;
+
+	rcu_read_lock();
+	hsr_for_each_port(master->hsr, port)
+		if ((port->type != HSR_PT_MASTER) && is_slave_up(port->dev)) {
+			has_carrier = true;
+			break;
+		}
+	rcu_read_unlock();
+
+	if (has_carrier)
+		netif_carrier_on(master->dev);
+	else
+		netif_carrier_off(master->dev);
+
+	return has_carrier;
+}
+
+
+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;
+		hsr->announce_timer.expires = jiffies +
+				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
+		add_timer(&hsr->announce_timer);
+	}
+
+	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;
+	rcu_read_lock();
+	hsr_for_each_port(hsr, port)
+		if (port->type != HSR_PT_MASTER)
+			mtu_max = min(port->dev->mtu, mtu_max);
+	rcu_read_unlock();
+
+	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;
+	struct hsr_port *master;
+
+	hsr = netdev_priv(dev);
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+
+	if (new_mtu > hsr_get_max_mtu(hsr)) {
+		netdev_info(master->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';
+
+	rcu_read_lock();
+	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);
+	}
+	rcu_read_unlock();
+
+	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 int 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);
+	skb->dev = master->dev;
+	hsr_forward_skb(skb, master);
+
+	return NETDEV_TX_OK;
+}
+
+
+static const struct header_ops hsr_header_ops = {
+	.create	 = eth_header,
+	.parse	 = eth_header_parse,
+};
+
+
+/* HSR:2010 supervision frames should be padded so that the whole frame,
+ * including headers and FCS, is 64 bytes (without VLAN).
+ */
+static int hsr_pad(int size)
+{
+	const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;
+
+	if (size >= min_size)
+		return size;
+	return min_size;
+}
+
+static void send_hsr_supervision_frame(struct hsr_port *master, u8 type)
+{
+	struct sk_buff *skb;
+	int hlen, tlen;
+	struct hsr_sup_tag *hsr_stag;
+	struct hsr_sup_payload *hsr_sp;
+	unsigned long irqflags;
+
+	hlen = LL_RESERVED_SPACE(master->dev);
+	tlen = master->dev->needed_tailroom;
+	skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
+			GFP_ATOMIC);
+
+	if (skb == NULL)
+		return;
+
+	skb_reserve(skb, hlen);
+
+	skb->dev = master->dev;
+	skb->protocol = htons(ETH_P_PRP);
+	skb->priority = TC_PRIO_CONTROL;
+
+	if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
+			    master->hsr->sup_multicast_addr,
+			    skb->dev->dev_addr, skb->len) <= 0)
+		goto out;
+	skb_reset_mac_header(skb);
+
+	hsr_stag = (typeof(hsr_stag)) skb_put(skb, sizeof(*hsr_stag));
+
+	set_hsr_stag_path(hsr_stag, 0xf);
+	set_hsr_stag_HSR_Ver(hsr_stag, 0);
+
+	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
+	hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
+	master->hsr->sequence_nr++;
+	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
+
+	hsr_stag->HSR_TLV_Type = type;
+	hsr_stag->HSR_TLV_Length = 12;
+
+	/* Payload: MacAddressA */
+	hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
+	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
+
+	hsr_forward_skb(skb, master);
+	return;
+
+out:
+	WARN_ON_ONCE("HSR: Could not send supervision frame\n");
+	kfree_skb(skb);
+}
+
+
+/* Announce (supervision frame) timer function
+ */
+static void hsr_announce(unsigned long data)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *master;
+
+	hsr = (struct hsr_priv *) data;
+
+	rcu_read_lock();
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+
+	if (hsr->announce_count < 3) {
+		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE);
+		hsr->announce_count++;
+	} else {
+		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK);
+	}
+
+	if (hsr->announce_count < 3)
+		hsr->announce_timer.expires = jiffies +
+				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
+	else
+		hsr->announce_timer.expires = jiffies +
+				msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
+
+	if (is_admin_up(master->dev))
+		add_timer(&hsr->announce_timer);
+
+	rcu_read_unlock();
+}
+
+
+/* According to comments in the declaration of struct net_device, this function
+ * is "Called from unregister, can be used to call free_netdev". Ok then...
+ */
+static void hsr_dev_destroy(struct net_device *hsr_dev)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *port;
+
+	hsr = netdev_priv(hsr_dev);
+
+	rtnl_lock();
+	hsr_for_each_port(hsr, port)
+		hsr_del_port(port);
+	rtnl_unlock();
+
+	del_timer_sync(&hsr->prune_timer);
+	del_timer_sync(&hsr->announce_timer);
+
+	synchronize_rcu();
+	free_netdev(hsr_dev);
+}
+
+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",
+};
+
+void hsr_dev_setup(struct net_device *dev)
+{
+	random_ether_addr(dev->dev_addr);
+
+	ether_setup(dev);
+	dev->header_ops = &hsr_header_ops;
+	dev->netdev_ops = &hsr_device_ops;
+	SET_NETDEV_DEVTYPE(dev, &hsr_type);
+	dev->tx_queue_len = 0;
+
+	dev->destructor = hsr_dev_destroy;
+
+	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.
+ */
+inline bool is_hsr_master(struct net_device *dev)
+{
+	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
+}
+
+/* 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)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *port;
+	int res;
+
+	hsr = netdev_priv(hsr_dev);
+	INIT_LIST_HEAD(&hsr->ports);
+	INIT_LIST_HEAD(&hsr->node_db);
+	INIT_LIST_HEAD(&hsr->self_node_db);
+
+	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
+
+	/* Make sure we recognize frames from ourselves in hsr_rcv() */
+	res = hsr_create_self_node(&hsr->self_node_db, 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;
+
+	init_timer(&hsr->announce_timer);
+	hsr->announce_timer.function = hsr_announce;
+	hsr->announce_timer.data = (unsigned long) hsr;
+
+	init_timer(&hsr->prune_timer);
+	hsr->prune_timer.function = hsr_prune_nodes;
+	hsr->prune_timer.data = (unsigned long) hsr;
+
+	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
+	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
+
+	/* FIXME: should I modify the value of these?
+	 *
+	 * - hsr_dev->flags - i.e.
+	 *			IFF_MASTER/SLAVE?
+	 * - hsr_dev->priv_flags - i.e.
+	 *			IFF_EBRIDGE?
+	 *			IFF_TX_SKB_SHARING?
+	 *			IFF_HSR_MASTER/SLAVE?
+	 */
+
+	/* 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);
+	if (res)
+		return res;
+
+	res = register_netdevice(hsr_dev);
+	if (res)
+		goto fail;
+
+	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
+	if (res)
+		goto fail;
+	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
+	if (res)
+		goto fail;
+
+	hsr->prune_timer.expires = jiffies + msecs_to_jiffies(PRUNE_PERIOD);
+	add_timer(&hsr->prune_timer);
+
+	return 0;
+
+fail:
+	hsr_for_each_port(hsr, port)
+		hsr_del_port(port);
+
+	return res;
+}
diff --git a/net/hsr/hsr_device.h b/net/hsr/hsr_device.h
new file mode 100644
index 000000000..108a5d59d
--- /dev/null
+++ b/net/hsr/hsr_device.h
@@ -0,0 +1,25 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#ifndef __HSR_DEVICE_H
+#define __HSR_DEVICE_H
+
+#include <linux/netdevice.h>
+#include "hsr_main.h"
+
+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);
+void hsr_check_carrier_and_operstate(struct hsr_priv *hsr);
+bool is_hsr_master(struct net_device *dev);
+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..7871ed6d3
--- /dev/null
+++ b/net/hsr/hsr_forward.c
@@ -0,0 +1,368 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#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;
+
+struct hsr_frame_info {
+	struct sk_buff *skb_std;
+	struct sk_buff *skb_hsr;
+	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;
+};
+
+
+/* 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 hsr_ethhdr_sp *hdr;
+
+	WARN_ON_ONCE(!skb_mac_header_was_set(skb));
+	hdr = (struct hsr_ethhdr_sp *) skb_mac_header(skb);
+
+	if (!ether_addr_equal(hdr->ethhdr.h_dest,
+			      hsr->sup_multicast_addr))
+		return false;
+
+	if (get_hsr_stag_path(&hdr->hsr_sup) != 0x0f)
+		return false;
+	if ((hdr->hsr_sup.HSR_TLV_Type != HSR_TLV_ANNOUNCE) &&
+	    (hdr->hsr_sup.HSR_TLV_Type != HSR_TLV_LIFE_CHECK))
+		return false;
+	if (hdr->hsr_sup.HSR_TLV_Length != 12)
+		return false;
+
+	return true;
+}
+
+
+static struct sk_buff *create_stripped_skb(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 == NULL)
+		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;
+}
+
+static struct sk_buff *frame_get_stripped_skb(struct hsr_frame_info *frame,
+					      struct hsr_port *port)
+{
+	if (!frame->skb_std)
+		frame->skb_std = create_stripped_skb(frame->skb_hsr, frame);
+	return skb_clone(frame->skb_std, GFP_ATOMIC);
+}
+
+
+static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame,
+			 struct hsr_port *port)
+{
+	struct hsr_ethhdr *hsr_ethhdr;
+	int lane_id;
+	int lsdu_size;
+
+	if (port->type == HSR_PT_SLAVE_A)
+		lane_id = 0;
+	else
+		lane_id = 1;
+
+	lsdu_size = skb->len - 14;
+	if (frame->is_vlan)
+		lsdu_size -= 4;
+
+	hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
+
+	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id);
+	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(ETH_P_PRP);
+}
+
+static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o,
+					 struct hsr_frame_info *frame,
+					 struct hsr_port *port)
+{
+	int movelen;
+	unsigned char *dst, *src;
+	struct sk_buff *skb;
+
+	/* Create the new skb with enough headroom to fit the HSR tag */
+	skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC);
+	if (skb == NULL)
+		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);
+
+	hsr_fill_tag(skb, frame, port);
+
+	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'.
+ */
+static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame,
+					    struct hsr_port *port)
+{
+	if (frame->skb_hsr)
+		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
+
+	if ((port->type != HSR_PT_SLAVE_A) && (port->type != HSR_PT_SLAVE_B)) {
+		WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port");
+		return NULL;
+	}
+
+	return create_tagged_skb(frame->skb_std, 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;
+
+	was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
+	hsr_addr_subst_source(node_src, skb);
+	skb_pull(skb, ETH_HLEN);
+	res = netif_rx(skb);
+	if (res == NET_RX_DROP) {
+		dev->stats.rx_dropped++;
+	} else {
+		dev->stats.rx_packets++;
+		dev->stats.rx_bytes += skb->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);
+}
+
+
+/* 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
+ * - 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;
+
+	hsr_for_each_port(frame->port_rcv->hsr, port) {
+		/* 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;
+
+		/* Don't send frame over port where it has been sent before */
+		if (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->skb_hsr,
+					     frame->node_src,
+					     frame->port_rcv);
+			continue;
+		}
+
+		if (port->type != HSR_PT_MASTER)
+			skb = frame_get_tagged_skb(frame, port);
+		else
+			skb = frame_get_stripped_skb(frame, port);
+		if (skb == NULL) {
+			/* FIXME: Record the dropped frame? */
+			continue;
+		}
+
+		skb->dev = port->dev;
+		if (port->type == HSR_PT_MASTER)
+			hsr_deliver_master(skb, port->dev, frame->node_src);
+		else
+			hsr_xmit(skb, port, frame);
+	}
+}
+
+
+static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
+			     struct hsr_frame_info *frame)
+{
+	struct net_device *master_dev;
+
+	master_dev = hsr_port_get_hsr(hsr, HSR_PT_MASTER)->dev;
+
+	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 int hsr_fill_frame_info(struct hsr_frame_info *frame,
+			       struct sk_buff *skb, struct hsr_port *port)
+{
+	struct ethhdr *ethhdr;
+	unsigned long irqflags;
+
+	frame->is_supervision = is_supervision_frame(port->hsr, skb);
+	frame->node_src = hsr_get_node(&port->hsr->node_db, skb,
+				       frame->is_supervision);
+	if (frame->node_src == NULL)
+		return -1; /* Unknown node and !is_supervision, or no mem */
+
+	ethhdr = (struct ethhdr *) skb_mac_header(skb);
+	frame->is_vlan = false;
+	if (ethhdr->h_proto == htons(ETH_P_8021Q)) {
+		frame->is_vlan = true;
+		/* FIXME: */
+		WARN_ONCE(1, "HSR: VLAN not yet supported");
+	}
+	if (ethhdr->h_proto == htons(ETH_P_PRP)) {
+		frame->skb_std = NULL;
+		frame->skb_hsr = skb;
+		frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
+	} else {
+		frame->skb_std = skb;
+		frame->skb_hsr = NULL;
+		/* Sequence nr for the master node */
+		spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags);
+		frame->sequence_nr = port->hsr->sequence_nr;
+		port->hsr->sequence_nr++;
+		spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags);
+	}
+
+	frame->port_rcv = port;
+	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;
+
+	if (skb_mac_header(skb) != skb->data) {
+		WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n",
+			  __FILE__, __LINE__, port->dev->name);
+		goto out_drop;
+	}
+
+	if (hsr_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);
+
+	if (frame.skb_hsr != NULL)
+		kfree_skb(frame.skb_hsr);
+	if (frame.skb_std != NULL)
+		kfree_skb(frame.skb_std);
+	return;
+
+out_drop:
+	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..5c5bc4b6b
--- /dev/null
+++ b/net/hsr/hsr_forward.h
@@ -0,0 +1,20 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#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);
+
+#endif /* __HSR_FORWARD_H */
diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
new file mode 100644
index 000000000..bace124d1
--- /dev/null
+++ b/net/hsr/hsr_framereg.c
@@ -0,0 +1,490 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * 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.
+ */
+
+#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"
+
+
+struct hsr_node {
+	struct list_head	mac_list;
+	unsigned char		MacAddressA[ETH_ALEN];
+	unsigned char		MacAddressB[ETH_ALEN];
+	/* Local slave through which AddrB frames are received from this node */
+	enum hsr_port_type	AddrB_port;
+	unsigned long		time_in[HSR_PT_PORTS];
+	bool			time_in_stale[HSR_PT_PORTS];
+	u16			seq_out[HSR_PT_PORTS];
+	struct rcu_head		rcu_head;
+};
+
+
+/*	TODO: use hash lists for mac addresses (linux/jhash.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_after_or_eq(a, b)	(!seq_nr_before((a), (b)))
+#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_node *node;
+
+	node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
+				      mac_list);
+	if (!node) {
+		WARN_ONCE(1, "HSR: No self node\n");
+		return false;
+	}
+
+	if (ether_addr_equal(addr, node->MacAddressA))
+		return true;
+	if (ether_addr_equal(addr, node->MacAddressB))
+		return true;
+
+	return false;
+}
+
+/* Search for mac entry. Caller must hold rcu read lock.
+ */
+static struct hsr_node *find_node_by_AddrA(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->MacAddressA, addr))
+			return node;
+	}
+
+	return NULL;
+}
+
+
+/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
+ * frames from self that's been looped over the HSR ring.
+ */
+int hsr_create_self_node(struct list_head *self_node_db,
+			 unsigned char addr_a[ETH_ALEN],
+			 unsigned char addr_b[ETH_ALEN])
+{
+	struct hsr_node *node, *oldnode;
+
+	node = kmalloc(sizeof(*node), GFP_KERNEL);
+	if (!node)
+		return -ENOMEM;
+
+	ether_addr_copy(node->MacAddressA, addr_a);
+	ether_addr_copy(node->MacAddressB, addr_b);
+
+	rcu_read_lock();
+	oldnode = list_first_or_null_rcu(self_node_db,
+						struct hsr_node, mac_list);
+	if (oldnode) {
+		list_replace_rcu(&oldnode->mac_list, &node->mac_list);
+		rcu_read_unlock();
+		synchronize_rcu();
+		kfree(oldnode);
+	} else {
+		rcu_read_unlock();
+		list_add_tail_rcu(&node->mac_list, self_node_db);
+	}
+
+	return 0;
+}
+
+
+/* Allocate an hsr_node and add it to node_db. 'addr' is the node's AddressA;
+ * seq_out is used to initialize filtering of outgoing duplicate frames
+ * originating from the newly added node.
+ */
+struct hsr_node *hsr_add_node(struct list_head *node_db, unsigned char addr[],
+			      u16 seq_out)
+{
+	struct hsr_node *node;
+	unsigned long now;
+	int i;
+
+	node = kzalloc(sizeof(*node), GFP_ATOMIC);
+	if (!node)
+		return NULL;
+
+	ether_addr_copy(node->MacAddressA, addr);
+
+	/* 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++)
+		node->time_in[i] = now;
+	for (i = 0; i < HSR_PT_PORTS; i++)
+		node->seq_out[i] = seq_out;
+
+	list_add_tail_rcu(&node->mac_list, node_db);
+
+	return node;
+}
+
+/* Get the hsr_node from which 'skb' was sent.
+ */
+struct hsr_node *hsr_get_node(struct list_head *node_db, struct sk_buff *skb,
+			      bool is_sup)
+{
+	struct hsr_node *node;
+	struct ethhdr *ethhdr;
+	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->MacAddressA, ethhdr->h_source))
+			return node;
+		if (ether_addr_equal(node->MacAddressB, ethhdr->h_source))
+			return node;
+	}
+
+	if (!is_sup)
+		return NULL; /* Only supervision frame may create node entry */
+
+	if (ethhdr->h_proto == htons(ETH_P_PRP)) {
+		/* 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 {
+		WARN_ONCE(1, "%s: Non-HSR frame\n", __func__);
+		seq_out = 0;
+	}
+
+	return hsr_add_node(node_db, ethhdr->h_source, seq_out);
+}
+
+/* Use the Supervision frame's info about an eventual MacAddressB for merging
+ * nodes that has previously had their MacAddressB registered as a separate
+ * node.
+ */
+void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr,
+			  struct hsr_port *port_rcv)
+{
+	struct hsr_node *node_real;
+	struct hsr_sup_payload *hsr_sp;
+	struct list_head *node_db;
+	int i;
+
+	skb_pull(skb, sizeof(struct hsr_ethhdr_sp));
+	hsr_sp = (struct hsr_sup_payload *) skb->data;
+
+	if (ether_addr_equal(eth_hdr(skb)->h_source, hsr_sp->MacAddressA))
+		/* Not sent from MacAddressB of a PICS_SUBS capable node */
+		goto done;
+
+	/* Merge node_curr (registered on MacAddressB) into node_real */
+	node_db = &port_rcv->hsr->node_db;
+	node_real = find_node_by_AddrA(node_db, hsr_sp->MacAddressA);
+	if (!node_real)
+		/* No frame received from AddrA of this node yet */
+		node_real = hsr_add_node(node_db, hsr_sp->MacAddressA,
+					 HSR_SEQNR_START - 1);
+	if (!node_real)
+		goto done; /* No mem */
+	if (node_real == node_curr)
+		/* Node has already been merged */
+		goto done;
+
+	ether_addr_copy(node_real->MacAddressB, eth_hdr(skb)->h_source);
+	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];
+	}
+	node_real->AddrB_port = port_rcv->type;
+
+	list_del_rcu(&node_curr->mac_list);
+	kfree_rcu(node_curr, rcu_head);
+
+done:
+	skb_push(skb, sizeof(struct hsr_ethhdr_sp));
+}
+
+
+/* '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 (MacAddressA) 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->MacAddressA, 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_AddrA(&port->hsr->node_db, eth_hdr(skb)->h_dest);
+	if (!node_dst) {
+		WARN_ONCE(1, "%s: Unknown node\n", __func__);
+		return;
+	}
+	if (port->type != node_dst->AddrB_port)
+		return;
+
+	ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->MacAddressB);
+}
+
+
+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 (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)
+{
+	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
+		return 1;
+
+	node->seq_out[port->type] = sequence_nr;
+	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(unsigned long data)
+{
+	struct hsr_priv *hsr;
+	struct hsr_node *node;
+	struct hsr_port *port;
+	unsigned long timestamp;
+	unsigned long time_a, time_b;
+
+	hsr = (struct hsr_priv *) data;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
+		/* 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 != NULL)
+				hsr_nl_ringerror(hsr, node->MacAddressA, 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->MacAddressA);
+			list_del_rcu(&node->mac_list);
+			/* Note that we need to free this entry later: */
+			kfree_rcu(node, rcu_head);
+		}
+	}
+	rcu_read_unlock();
+}
+
+
+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->MacAddressA);
+		return node;
+	}
+
+	node = _pos;
+	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
+		ether_addr_copy(addr, node->MacAddressA);
+		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;
+
+
+	rcu_read_lock();
+	node = find_node_by_AddrA(&hsr->node_db, addr);
+	if (!node) {
+		rcu_read_unlock();
+		return -ENOENT;	/* No such entry */
+	}
+
+	ether_addr_copy(addr_b, node->MacAddressB);
+
+	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->AddrB_port != HSR_PT_NONE) {
+		port = hsr_port_get_hsr(hsr, node->AddrB_port);
+		*addr_b_ifindex = port->dev->ifindex;
+	} else {
+		*addr_b_ifindex = -1;
+	}
+
+	rcu_read_unlock();
+
+	return 0;
+}
diff --git a/net/hsr/hsr_framereg.h b/net/hsr/hsr_framereg.h
new file mode 100644
index 000000000..438b40f98
--- /dev/null
+++ b/net/hsr/hsr_framereg.h
@@ -0,0 +1,54 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#ifndef __HSR_FRAMEREG_H
+#define __HSR_FRAMEREG_H
+
+#include "hsr_main.h"
+
+struct hsr_node;
+
+struct hsr_node *hsr_add_node(struct list_head *node_db, unsigned char addr[],
+			      u16 seq_out);
+struct hsr_node *hsr_get_node(struct list_head *node_db, struct sk_buff *skb,
+			      bool is_sup);
+void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr,
+			  struct hsr_port *port);
+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(unsigned long data);
+
+int hsr_create_self_node(struct list_head *self_node_db,
+			 unsigned char addr_a[ETH_ALEN],
+			 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);
+
+#endif /* __HSR_FRAMEREG_H */
diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
new file mode 100644
index 000000000..cd37d0011
--- /dev/null
+++ b/net/hsr/hsr_main.c
@@ -0,0 +1,136 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#include <linux/netdevice.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 int hsr_netdev_notify(struct notifier_block *nb, unsigned long event,
+			     void *ptr)
+{
+	struct net_device *dev;
+	struct hsr_port *port, *master;
+	struct hsr_priv *hsr;
+	int mtu_max;
+	int res;
+
+	dev = netdev_notifier_info_to_dev(ptr);
+	port = hsr_port_get_rtnl(dev);
+	if (port == NULL) {
+		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 == NULL) {
+			/* 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_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) {
+			ether_addr_copy(master->dev->dev_addr, 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->self_node_db,
+					   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:
+		hsr_del_port(port);
+		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;
+}
+
+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)
+{
+	unregister_netdevice_notifier(&hsr_nb);
+	hsr_netlink_exit();
+}
+
+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..5a9c69962
--- /dev/null
+++ b/net/hsr/hsr_main.h
@@ -0,0 +1,183 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#ifndef __HSR_PRIVATE_H
+#define __HSR_PRIVATE_H
+
+#include <linux/netdevice.h>
+#include <linux/list.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 */
+
+
+/* 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)
+
+
+/* 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_ANNOUNCE		   22
+#define HSR_TLV_LIFE_CHECK		   23
+
+
+/* HSR Tag.
+ * As defined in IEC-62439-3:2010, the HSR tag is really { ethertype = 0x88FB,
+ * path, LSDU_size, sequence Nr }. But we let eth_header() create { h_dest,
+ * h_source, h_proto = 0x88FB }, and add { path, LSDU_size, sequence Nr,
+ * encapsulated protocol } instead.
+ *
+ * Field names as defined in the IEC:2010 standard for HSR.
+ */
+struct hsr_tag {
+	__be16		path_and_LSDU_size;
+	__be16		sequence_nr;
+	__be16		encap_proto;
+} __packed;
+
+#define HSR_HLEN	6
+
+/* 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 u16 get_hsr_tag_path(struct hsr_tag *ht)
+{
+	return ntohs(ht->path_and_LSDU_size) >> 12;
+}
+
+static inline u16 get_hsr_tag_LSDU_size(struct hsr_tag *ht)
+{
+	return ntohs(ht->path_and_LSDU_size) & 0x0FFF;
+}
+
+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;
+
+
+/* HSR 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;
+	__u8		HSR_TLV_Type;
+	__u8		HSR_TLV_Length;
+} __packed;
+
+struct hsr_sup_payload {
+	unsigned char	MacAddressA[ETH_ALEN];
+} __packed;
+
+static inline u16 get_hsr_stag_path(struct hsr_sup_tag *hst)
+{
+	return get_hsr_tag_path((struct hsr_tag *) hst);
+}
+
+static inline u16 get_hsr_stag_HSR_ver(struct hsr_sup_tag *hst)
+{
+	return get_hsr_tag_LSDU_size((struct hsr_tag *) hst);
+}
+
+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 hsr_ethhdr_sp {
+	struct ethhdr		ethhdr;
+	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 */
+};
+
+struct hsr_port {
+	struct list_head	port_list;
+	struct net_device	*dev;
+	struct hsr_priv		*hsr;
+	enum hsr_port_type	type;
+};
+
+struct hsr_priv {
+	struct rcu_head		rcu_head;
+	struct list_head	ports;
+	struct list_head	node_db;	/* Known HSR nodes */
+	struct list_head	self_node_db;	/* MACs of slaves */
+	struct timer_list	announce_timer;	/* Supervision frame dispatch */
+	struct timer_list	prune_timer;
+	int announce_count;
+	u16 sequence_nr;
+	spinlock_t seqnr_lock;			/* locking for sequence_nr */
+	unsigned char		sup_multicast_addr[ETH_ALEN];
+};
+
+#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);
+}
+
+#endif /*  __HSR_PRIVATE_H */
diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
new file mode 100644
index 000000000..a2c7e4c0a
--- /dev/null
+++ b/net/hsr/hsr_netlink.c
@@ -0,0 +1,493 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * Routines for handling Netlink messages for HSR.
+ */
+
+#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_SUPERVISION_ADDR]	= { .type = NLA_BINARY, .len = ETH_ALEN },
+	[IFLA_HSR_SEQ_NR]		= { .type = NLA_U16 },
+};
+
+
+/* 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 net_device *link[2];
+	unsigned char multicast_spec;
+
+	if (!data) {
+		netdev_info(dev, "HSR: No slave devices specified\n");
+		return -EINVAL;
+	}
+	if (!data[IFLA_HSR_SLAVE1]) {
+		netdev_info(dev, "HSR: Slave1 device not specified\n");
+		return -EINVAL;
+	}
+	link[0] = __dev_get_by_index(src_net, nla_get_u32(data[IFLA_HSR_SLAVE1]));
+	if (!data[IFLA_HSR_SLAVE2]) {
+		netdev_info(dev, "HSR: Slave2 device not specified\n");
+		return -EINVAL;
+	}
+	link[1] = __dev_get_by_index(src_net, nla_get_u32(data[IFLA_HSR_SLAVE2]));
+
+	if (!link[0] || !link[1])
+		return -ENODEV;
+	if (link[0] == link[1])
+		return -EINVAL;
+
+	if (!data[IFLA_HSR_MULTICAST_SPEC])
+		multicast_spec = 0;
+	else
+		multicast_spec = nla_get_u8(data[IFLA_HSR_MULTICAST_SPEC]);
+
+	return hsr_dev_finalize(dev, link, multicast_spec);
+}
+
+static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct hsr_priv *hsr;
+	struct hsr_port *port;
+	int res;
+
+	hsr = netdev_priv(dev);
+
+	res = 0;
+
+	rcu_read_lock();
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (port)
+		res = nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex);
+	rcu_read_unlock();
+	if (res)
+		goto nla_put_failure;
+
+	rcu_read_lock();
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+	if (port)
+		res = nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex);
+	rcu_read_unlock();
+	if (res)
+		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;
+
+	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,
+	.fill_info	= hsr_fill_info,
+};
+
+
+
+/* attribute policy */
+/* NLA_BINARY missing in libnl; use NLA_UNSPEC in userspace instead. */
+static const struct nla_policy hsr_genl_policy[HSR_A_MAX + 1] = {
+	[HSR_A_NODE_ADDR] = { .type = NLA_BINARY, .len = ETH_ALEN },
+	[HSR_A_NODE_ADDR_B] = { .type = NLA_BINARY, .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 = {
+	.id = GENL_ID_GENERATE,
+	.hdrsize = 0,
+	.name = "HSR",
+	.version = 1,
+	.maxattr = HSR_A_MAX,
+};
+
+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;
+
+	hsr_dev = __dev_get_by_index(genl_info_net(info),
+					nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+	if (!hsr_dev)
+		goto invalid;
+	if (!is_hsr_master(hsr_dev))
+		goto invalid;
+
+
+	/* Send reply */
+
+	skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	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;
+	rcu_read_lock();
+	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);
+	rcu_read_unlock();
+	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;
+	rcu_read_lock();
+	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);
+	rcu_read_unlock();
+	if (res < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb_out, msg_head);
+	genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
+
+	return 0;
+
+invalid:
+	netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL);
+	return 0;
+
+nla_put_failure:
+	kfree_skb(skb_out);
+	/* Fall through */
+
+fail:
+	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)
+{
+	/* For receiving */
+	struct nlattr *na;
+	struct net_device *hsr_dev;
+
+	/* For sending */
+	struct sk_buff *skb_out;
+	void *msg_head;
+	struct hsr_priv *hsr;
+	void *pos;
+	unsigned char addr[ETH_ALEN];
+	int res;
+
+	if (!info)
+		goto invalid;
+
+	na = info->attrs[HSR_A_IFINDEX];
+	if (!na)
+		goto invalid;
+
+	hsr_dev = __dev_get_by_index(genl_info_net(info),
+				     nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+	if (!hsr_dev)
+		goto invalid;
+	if (!is_hsr_master(hsr_dev))
+		goto invalid;
+
+
+	/* Send reply */
+
+	skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	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;
+	}
+
+	res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	hsr = netdev_priv(hsr_dev);
+
+	rcu_read_lock();
+	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) {
+			rcu_read_unlock();
+			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;
+
+invalid:
+	netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL);
+	return 0;
+
+nla_put_failure:
+	kfree_skb(skb_out);
+	/* Fall through */
+
+fail:
+	return res;
+}
+
+
+static const struct genl_ops hsr_ops[] = {
+	{
+		.cmd = HSR_C_GET_NODE_STATUS,
+		.flags = 0,
+		.policy = hsr_genl_policy,
+		.doit = hsr_get_node_status,
+		.dumpit = NULL,
+	},
+	{
+		.cmd = HSR_C_GET_NODE_LIST,
+		.flags = 0,
+		.policy = hsr_genl_policy,
+		.doit = hsr_get_node_list,
+		.dumpit = NULL,
+	},
+};
+
+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_with_ops_groups(&hsr_genl_family, hsr_ops,
+						  hsr_mcgrps);
+	if (rc)
+		goto fail_genl_register_family;
+
+	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..3f6b95b5b
--- /dev/null
+++ b/net/hsr/hsr_netlink.h
@@ -0,0 +1,31 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#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]);
+void hsr_nl_framedrop(int dropcount, int dev_idx);
+void hsr_nl_linkdown(int dev_idx);
+
+#endif /* __HSR_NETLINK_H */
diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
new file mode 100644
index 000000000..7d37366cc
--- /dev/null
+++ b/net/hsr/hsr_slave.c
@@ -0,0 +1,200 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#include "hsr_slave.h"
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include "hsr_main.h"
+#include "hsr_device.h"
+#include "hsr_forward.h"
+#include "hsr_framereg.h"
+
+
+static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
+{
+	struct sk_buff *skb = *pskb;
+	struct hsr_port *port;
+
+	if (!skb_mac_header_was_set(skb)) {
+		WARN_ONCE(1, "%s: skb invalid", __func__);
+		return RX_HANDLER_PASS;
+	}
+
+	rcu_read_lock(); /* hsr->node_db, hsr->ports */
+	port = hsr_port_get_rcu(skb->dev);
+
+	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
+		/* Directly kill frames sent by ourselves */
+		kfree_skb(skb);
+		goto finish_consume;
+	}
+
+	if (eth_hdr(skb)->h_proto != htons(ETH_P_PRP))
+		goto finish_pass;
+
+	skb_push(skb, ETH_HLEN);
+
+	hsr_forward_skb(skb, port);
+
+finish_consume:
+	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
+	return RX_HANDLER_CONSUMED;
+
+finish_pass:
+	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
+	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)
+{
+	/* Don't allow HSR on non-ethernet like devices */
+	if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
+	    (dev->addr_len != ETH_ALEN)) {
+		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
+		return -EINVAL;
+	}
+
+	/* Don't allow enslaving hsr devices */
+	if (is_hsr_master(dev)) {
+		netdev_info(dev, "Cannot create trees of HSR devices.\n");
+		return -EINVAL;
+	}
+
+	if (hsr_port_exists(dev)) {
+		netdev_info(dev, "This device is already a HSR slave.\n");
+		return -EINVAL;
+	}
+
+	if (dev->priv_flags & IFF_802_1Q_VLAN) {
+		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
+		return -EINVAL;
+	}
+
+	if (dev->priv_flags & IFF_DONT_BRIDGE) {
+		netdev_info(dev, "This device does not support bridging.\n");
+		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 net_device *dev, struct hsr_port *port)
+{
+	int res;
+
+	dev_hold(dev);
+	res = dev_set_promiscuity(dev, 1);
+	if (res)
+		goto fail_promiscuity;
+
+	/* FIXME:
+	 * What does net device "adjacency" mean? Should we do
+	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
+	 */
+
+	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:
+	dev_set_promiscuity(dev, -1);
+fail_promiscuity:
+	dev_put(dev);
+
+	return res;
+}
+
+int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
+		 enum hsr_port_type type)
+{
+	struct hsr_port *port, *master;
+	int res;
+
+	if (type != HSR_PT_MASTER) {
+		res = hsr_check_dev_ok(dev);
+		if (res)
+			return res;
+	}
+
+	port = hsr_port_get_hsr(hsr, type);
+	if (port != NULL)
+		return -EBUSY;	/* This port already exists */
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (port == NULL)
+		return -ENOMEM;
+
+	if (type != HSR_PT_MASTER) {
+		res = hsr_portdev_setup(dev, port);
+		if (res)
+			goto fail_dev_setup;
+	}
+
+	port->hsr = hsr;
+	port->dev = dev;
+	port->type = type;
+
+	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) {
+		if (master != NULL) {
+			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);
+	}
+
+	/* FIXME?
+	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
+	 */
+
+	synchronize_rcu();
+
+	if (port != master)
+		dev_put(port->dev);
+}
diff --git a/net/hsr/hsr_slave.h b/net/hsr/hsr_slave.h
new file mode 100644
index 000000000..3ccfbf71c
--- /dev/null
+++ b/net/hsr/hsr_slave.h
@@ -0,0 +1,38 @@
+/* Copyright 2011-2014 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#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);
+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;
+}
+
+#endif /* __HSR_SLAVE_H */