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/20240308145729.490863-1-lukma@denx.de/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 <lukma@denx.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
index 26329db09210..614df9649794 100644
--- a/net/hsr/hsr_framereg.c
+++ b/net/hsr/hsr_framereg.c
@@ -71,6 +71,14 @@ static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
 	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.
  */
@@ -223,6 +231,15 @@ struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
 		}
 	}
 
+	/* 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;
+		}
+	}
+
 	/* Everyone may create a node entry, connected node to a HSR/PRP
 	 * device.
 	 */
@@ -418,6 +435,10 @@ void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
 
 	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__);
@@ -561,6 +582,37 @@ void hsr_prune_nodes(struct timer_list *t)
 		  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,
 			unsigned char addr[ETH_ALEN])
 {