net: hsr: Provide RedBox support (HSR-SAN)

Introduce RedBox support (HSR-SAN to be more precise) for HSR networks.
Following traffic reduction optimizations have been implemented:
- Do not send HSR supervisory frames to Port C (interlink)
- Do not forward to HSR ring frames addressed to Port C
- Do not forward to Port C frames from HSR ring
- Do not send duplicate HSR frame to HSR ring when destination is Port C

The corresponding patch to modify iptable2 sources has already been sent:
https://lore.kernel.org/netdev/[e-mail]/T/

Testing procedure (veth and netns):
-----------------------------------
One shall run:
linux-vanila/tools/testing/selftests/net/hsr/hsr_redbox.sh
(Detailed description of the setup one can find in the test
script file).

Testing procedure (real hardware):
----------------------------------
The EVB-KSZ9477 has been used for testing on net-next branch
(SHA1: 5fc68320c1fb3c7d456ddcae0b4757326a043e6f).

Ports 4/5 were used for SW managed HSR (hsr1) as first hsr0 for ports 1/2
(with HW offloading for ksz9477) was created. Port 3 has been used as
interlink port (single USB-ETH dongle).

Configuration - RedBox (EVB-KSZ9477):
if link set lan1 down;ip link set lan2 down
ip link add name hsr0 type hsr slave1 lan1 slave2 lan2 supervision 45 version 1
ip link add name hsr1 type hsr slave1 lan4 slave2 lan5 interlink lan3 supervision 45 version 1
ip link set lan4 up;ip link set lan5 up
ip link set lan3 up
ip addr add 192.168.0.11/24 dev hsr1
ip link set hsr1 up

Configuration - DAN-H (EVB-KSZ9477):

ip link set lan1 down;ip link set lan2 down
ip link add name hsr0 type hsr slave1 lan1 slave2 lan2 supervision 45 version 1
ip link add name hsr1 type hsr slave1 lan4 slave2 lan5 supervision 45 version 1
ip link set lan4 up;ip link set lan5 up
ip addr add 192.168.0.12/24 dev hsr1
ip link set hsr1 up

This approach uses only SW based HSR devices (hsr1).

-------------- ----------------- ------------
DAN-H Port5 | <------> | Port5 | |
Port4 | <------> | Port4 Port3 | <---> | PC
| | (RedBox) | | (USB-ETH)
EVB-KSZ9477 | | EVB-KSZ9477 | |
-------------- ----------------- ------------

Signed-off-by: Lukasz Majewski <[e-mail]>
Signed-off-by: Paolo Abeni <[e-mail]>

include/uapi/linux/if_link.h

···
 	IFLA_HSR_PROTOCOL,		/* Indicate different protocol than
 					 * HSR. For example PRP.
 					 */
+	IFLA_HSR_INTERLINK,		/* HSR interlink network device */
 	__IFLA_HSR_MAX,
 };
 

net/hsr/hsr_device.c

···
 		case HSR_PT_SLAVE_B:
 			designation = "Slave B";
 			break;
+		case HSR_PT_INTERLINK:
+			designation = "Interlink";
+			break;
 		default:
 			designation = "Unknown";
 		}
···
 	struct hsr_priv *hsr = master->hsr;
 	__u8 type = HSR_TLV_LIFE_CHECK;
 	struct hsr_sup_payload *hsr_sp;
+	struct hsr_sup_tlv *hsr_stlv;
 	struct hsr_sup_tag *hsr_stag;
 	struct sk_buff *skb;
 
···
 	/* Payload: MacAddressA */
 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 	ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
+
+	if (hsr->redbox) {
+		hsr_stlv = skb_put(skb, sizeof(struct hsr_sup_tlv));
+		hsr_stlv->HSR_TLV_type = PRP_TLV_REDBOX_MAC;
+		hsr_stlv->HSR_TLV_length = sizeof(struct hsr_sup_payload);
+
+		/* Payload: MacAddressRedBox */
+		hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
+		ether_addr_copy(hsr_sp->macaddress_A, hsr->macaddress_redbox);
+	}
 
 	if (skb_put_padto(skb, ETH_ZLEN)) {
 		spin_unlock_bh(&hsr->seqnr_lock);
···
 		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_INTERLINK);
 	if (port)
 		hsr_del_port(port);
 
···
 };
 
 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)
+		     struct net_device *interlink, unsigned char multicast_spec,
+		     u8 protocol_version, struct netlink_ext_ack *extack)
 {
 	bool unregister = false;
 	struct hsr_priv *hsr;
···
 	hsr = netdev_priv(hsr_dev);
 	INIT_LIST_HEAD(&hsr->ports);
 	INIT_LIST_HEAD(&hsr->node_db);
+	INIT_LIST_HEAD(&hsr->proxy_node_db);
 	spin_lock_init(&hsr->list_lock);
 
 	eth_hw_addr_set(hsr_dev, slave[0]->dev_addr);
···
 	/* Overflow soon to find bugs easier: */
 	hsr->sequence_nr = HSR_SEQNR_START;
 	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
+	hsr->interlink_sequence_nr = HSR_SEQNR_START;
 
 	timer_setup(&hsr->announce_timer, hsr_announce, 0);
 	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
···
 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B, extack);
 	if (res)
 		goto err_unregister;
+
+	if (interlink) {
+		res = hsr_add_port(hsr, interlink, HSR_PT_INTERLINK, extack);
+		if (res)
+			goto err_unregister;
+
+		hsr->redbox = true;
+		ether_addr_copy(hsr->macaddress_redbox, interlink->dev_addr);
+		timer_setup(&hsr->prune_proxy_timer, hsr_prune_proxy_nodes, 0);
+		mod_timer(&hsr->prune_proxy_timer,
+			  jiffies + msecs_to_jiffies(PRUNE_PROXY_PERIOD));
+	}
 
 	hsr_debugfs_init(hsr, hsr_dev);
 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));

net/hsr/hsr_device.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);
+		     struct net_device *interlink, 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 */

net/hsr/hsr_forward.c

···
 		 */
 		ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
 	}
+
+	/* When HSR node is used as RedBox - the frame received from HSR ring
+	 * requires source MAC address (SA) replacement to one which can be
+	 * recognized by SAN devices (otherwise, frames are dropped by switch)
+	 */
+	if (port->type == HSR_PT_INTERLINK)
+		ether_addr_copy(eth_hdr(skb)->h_source,
+				port->hsr->macaddress_redbox);
+
 	return dev_queue_xmit(skb);
 }
 
···
 
 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
 {
+	struct sk_buff *skb;
+
 	if (port->dev->features & NETIF_F_HW_HSR_FWD)
 		return prp_drop_frame(frame, port);
+
+	/* RedBox specific frames dropping policies
+	 *
+	 * Do not send HSR supervisory frames to SAN devices
+	 */
+	if (frame->is_supervision && port->type == HSR_PT_INTERLINK)
+		return true;
+
+	/* Do not forward to other HSR port (A or B) unicast frames which
+	 * are addressed to interlink port (and are in the ProxyNodeTable).
+	 */
+	skb = frame->skb_hsr;
+	if (skb && prp_drop_frame(frame, port) &&
+	    is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
+	    hsr_is_node_in_db(&port->hsr->proxy_node_db,
+			      eth_hdr(skb)->h_dest)) {
+		return true;
+	}
+
+	/* Do not forward to port C (Interlink) frames from nodes A and B
+	 * if DA is in NodeTable.
+	 */
+	if ((frame->port_rcv->type == HSR_PT_SLAVE_A ||
+	     frame->port_rcv->type == HSR_PT_SLAVE_B) &&
+	    port->type == HSR_PT_INTERLINK) {
+		skb = frame->skb_hsr;
+		if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
+		    hsr_is_node_in_db(&port->hsr->node_db,
+				      eth_hdr(skb)->h_dest)) {
+			return true;
+		}
+	}
+
+	/* Do not forward to port A and B unicast frames received on the
+	 * interlink port if it is addressed to one of nodes registered in
+	 * the ProxyNodeTable.
+	 */
+	if ((port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B) &&
+	    frame->port_rcv->type == HSR_PT_INTERLINK) {
+		skb = frame->skb_std;
+		if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
+		    hsr_is_node_in_db(&port->hsr->proxy_node_db,
+				      eth_hdr(skb)->h_dest)) {
+			return true;
+		}
+	}
 
 	return false;
 }
···
 		}
 
 		/* Check if frame is to be dropped. Eg. for PRP no forward
-		 * between ports.
+		 * between ports, or sending HSR supervision to RedBox.
 		 */
 		if (hsr->proto_ops->drop_frame &&
 		    hsr->proto_ops->drop_frame(frame, port))
 			continue;
 
-		if (port->type != HSR_PT_MASTER)
+		if (port->type == HSR_PT_SLAVE_A ||
+		    port->type == HSR_PT_SLAVE_B)
 			skb = hsr->proto_ops->create_tagged_frame(frame, port);
 		else
 			skb = hsr->proto_ops->get_untagged_frame(frame, port);
···
 			hsr_deliver_master(skb, port->dev, frame->node_src);
 		} else {
 			if (!hsr_xmit(skb, port, frame))
-				sent = true;
+				if (port->type == HSR_PT_SLAVE_A ||
+				    port->type == HSR_PT_SLAVE_B)
+					sent = true;
 		}
 	}
 }
···
 	frame->skb_prp = NULL;
 	frame->skb_std = skb;
 
-	if (port->type != HSR_PT_MASTER) {
+	if (port->type != HSR_PT_MASTER)
 		frame->is_from_san = true;
-	} else {
-		/* Sequence nr for the master node */
+
+	if (port->type == HSR_PT_MASTER ||
+	    port->type == HSR_PT_INTERLINK) {
+		/* Sequence nr for the master/interlink node */
 		lockdep_assert_held(&hsr->seqnr_lock);
 		frame->sequence_nr = hsr->sequence_nr;
 		hsr->sequence_nr++;
···
 {
 	struct hsr_priv *hsr = port->hsr;
 	struct hsr_vlan_ethhdr *vlan_hdr;
+	struct list_head *n_db;
 	struct ethhdr *ethhdr;
 	__be16 proto;
 	int ret;
···
 
 	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);
+
+	n_db = &hsr->node_db;
+	if (port->type == HSR_PT_INTERLINK)
+		n_db = &hsr->proxy_node_db;
+
+	frame->node_src = hsr_get_node(port, n_db, skb,
+				       frame->is_supervision, port->type);
 	if (!frame->node_src)
 		return -1; /* Unknown node and !is_supervision, or no mem */
 

net/hsr/hsr_framereg.c

···
 	return NULL;
 }
 
+/* Check if node for a given MAC address is already present in data base
+ */
+bool hsr_is_node_in_db(struct list_head *node_db,
+		       const unsigned char addr[ETH_ALEN])
+{
+	return !!find_node_by_addr_A(node_db, addr);
+}
+
 /* 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.
  */
···
 			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;
+		}
+	}
+
+	/* Check if required node is not in proxy nodes table */
+	list_for_each_entry_rcu(node, &hsr->proxy_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;
···
 
 	node_dst = find_node_by_addr_A(&port->hsr->node_db,
 				       eth_hdr(skb)->h_dest);
+	if (!node_dst && port->hsr->redbox)
+		node_dst = find_node_by_addr_A(&port->hsr->proxy_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__);
···
 	/* Restart timer */
 	mod_timer(&hsr->prune_timer,
 		  jiffies + msecs_to_jiffies(PRUNE_PERIOD));
+}
+
+void hsr_prune_proxy_nodes(struct timer_list *t)
+{
+	struct hsr_priv *hsr = from_timer(hsr, t, prune_proxy_timer);
+	unsigned long timestamp;
+	struct hsr_node *node;
+	struct hsr_node *tmp;
+
+	spin_lock_bh(&hsr->list_lock);
+	list_for_each_entry_safe(node, tmp, &hsr->proxy_node_db, mac_list) {
+		timestamp = node->time_in[HSR_PT_INTERLINK];
+
+		/* Prune old entries */
+		if (time_is_before_jiffies(timestamp +
+				msecs_to_jiffies(HSR_PROXY_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_proxy_timer,
+		  jiffies + msecs_to_jiffies(PRUNE_PROXY_PERIOD));
 }
 
 void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,

net/hsr/hsr_framereg.h

···
 			   u16 sequence_nr);
 
 void hsr_prune_nodes(struct timer_list *t);
+void hsr_prune_proxy_nodes(struct timer_list *t);
 
 int hsr_create_self_node(struct hsr_priv *hsr,
 			 const unsigned char addr_a[ETH_ALEN],
···
 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);
+
+bool hsr_is_node_in_db(struct list_head *node_db,
+		       const unsigned char addr[ETH_ALEN]);
 
 struct hsr_node {
 	struct list_head	mac_list;

net/hsr/hsr_main.h

···
  */
 #define HSR_LIFE_CHECK_INTERVAL		 2000 /* ms */
 #define HSR_NODE_FORGET_TIME		60000 /* ms */
+#define HSR_PROXY_NODE_FORGET_TIME	60000 /* ms */
 #define HSR_ANNOUNCE_INTERVAL		  100 /* ms */
 #define HSR_ENTRY_FORGET_TIME		  400 /* ms */
 
···
  * HSR_NODE_FORGET_TIME?
  */
 #define PRUNE_PERIOD			 3000 /* ms */
+#define PRUNE_PROXY_PERIOD		 3000 /* ms */
 #define HSR_TLV_EOT				   0  /* End of TLVs */
 #define HSR_TLV_ANNOUNCE		   22
 #define HSR_TLV_LIFE_CHECK		   23
···
 	struct rcu_head		rcu_head;
 	struct list_head	ports;
 	struct list_head	node_db;	/* Known HSR nodes */
+	struct list_head	proxy_node_db;	/* RedBox HSR proxy nodes */
 	struct hsr_self_node	__rcu *self_node;	/* MACs of slaves */
 	struct timer_list	announce_timer;	/* Supervision frame dispatch */
 	struct timer_list	prune_timer;
+	struct timer_list	prune_proxy_timer;
 	int announce_count;
 	u16 sequence_nr;
+	u16 interlink_sequence_nr; /* Interlink port seq_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 */
···
 				 * of lan_id
 				 */
 	bool fwd_offloaded;	/* Forwarding offloaded to HW */
+	bool redbox;            /* Device supports HSR RedBox */
+	unsigned char		macaddress_redbox[ETH_ALEN];
 	unsigned char		sup_multicast_addr[ETH_ALEN] __aligned(sizeof(u16));
 				/* Align to u16 boundary to avoid unaligned access
 				 * in ether_addr_equal

net/hsr/hsr_netlink.c

···
 	[IFLA_HSR_SUPERVISION_ADDR]	= { .len = ETH_ALEN },
 	[IFLA_HSR_SEQ_NR]		= { .type = NLA_U16 },
 	[IFLA_HSR_PROTOCOL]		= { .type = NLA_U8 },
+	[IFLA_HSR_INTERLINK]		= { .type = NLA_U32 },
 };
 
 /* Here, it seems a netdevice has already been allocated for us, and the
···
 	enum hsr_version proto_version;
 	unsigned char multicast_spec;
 	u8 proto = HSR_PROTOCOL_HSR;
-	struct net_device *link[2];
 
+	struct net_device *link[2], *interlink = NULL;
 	if (!data) {
 		NL_SET_ERR_MSG_MOD(extack, "No slave devices specified");
 		return -EINVAL;
···
 
 	if (link[0] == link[1]) {
 		NL_SET_ERR_MSG_MOD(extack, "Slave1 and Slave2 are same");
+		return -EINVAL;
+	}
+
+	if (data[IFLA_HSR_INTERLINK])
+		interlink = __dev_get_by_index(src_net,
+					       nla_get_u32(data[IFLA_HSR_INTERLINK]));
+
+	if (interlink && interlink == link[0]) {
+		NL_SET_ERR_MSG_MOD(extack, "Interlink and Slave1 are the same");
+		return -EINVAL;
+	}
+
+	if (interlink && interlink == link[1]) {
+		NL_SET_ERR_MSG_MOD(extack, "Interlink and Slave2 are the same");
 		return -EINVAL;
 	}
 
···
 		}
 	}
 
-	if (proto == HSR_PROTOCOL_PRP)
+	if (proto == HSR_PROTOCOL_PRP) {
 		proto_version = PRP_V1;
+		if (interlink) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Interlink only works with HSR");
+			return -EINVAL;
+		}
+	}
 
-	return hsr_dev_finalize(dev, link, multicast_spec, proto_version, extack);
+	return hsr_dev_finalize(dev, link, interlink, 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->prune_proxy_timer);
 	del_timer_sync(&hsr->announce_timer);
 
 	hsr_debugfs_term(hsr);
···
 
 	hsr_del_self_node(hsr);
 	hsr_del_nodes(&hsr->node_db);
+	hsr_del_nodes(&hsr->proxy_node_db);
 
 	unregister_netdevice_queue(dev, head);
 }

net/hsr/hsr_slave.c

···
 	protocol = eth_hdr(skb)->h_proto;
 
 	if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
+	    port->type != HSR_PT_INTERLINK &&
 	    hsr->proto_ops->invalid_dan_ingress_frame &&
 	    hsr->proto_ops->invalid_dan_ingress_frame(protocol))
 		goto finish_pass;