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, 76 insertions, 9 deletions

diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index 5d68cb181695..05a61b8286ec 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -377,6 +377,15 @@ static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
 		 */
 		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);
 }
 
@@ -390,9 +399,57 @@ bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
 
 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
 {
+	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;
 }
 
@@ -448,13 +505,14 @@ static void hsr_forward_do(struct hsr_frame_info *frame)
 		}
 
 		/* 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);
@@ -469,7 +527,9 @@ static void hsr_forward_do(struct hsr_frame_info *frame)
 			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;
 		}
 	}
 }
@@ -503,10 +563,12 @@ static void handle_std_frame(struct sk_buff *skb,
 	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++;
@@ -564,6 +626,7 @@ static int fill_frame_info(struct hsr_frame_info *frame,
 {
 	struct hsr_priv *hsr = port->hsr;
 	struct hsr_vlan_ethhdr *vlan_hdr;
+	struct list_head *n_db;
 	struct ethhdr *ethhdr;
 	__be16 proto;
 	int ret;
@@ -574,9 +637,13 @@ static int fill_frame_info(struct hsr_frame_info *frame,
 
 	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 */