net: bridge: mrp: Update the Test frames for MRA

According to the standard IEC 62439-2, in case the node behaves as MRA
and needs to send Test frames on ring ports, then these Test frames need
to have an Option TLV and a Sub-Option TLV which has the type AUTO_MGR.

Signed-off-by: Horatiu Vultur <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/bridge/br_mrp.c

···
 	hdr->timestamp = cpu_to_be32(jiffies_to_msecs(jiffies));
 
 	br_mrp_skb_common(skb, mrp);
+
+	/* In case the node behaves as MRA then the Test frame needs to have
+	 * an Option TLV which includes eventually a sub-option TLV that has
+	 * the type AUTO_MGR
+	 */
+	if (mrp->ring_role == BR_MRP_RING_ROLE_MRA) {
+		struct br_mrp_sub_option1_hdr *sub_opt = NULL;
+		struct br_mrp_tlv_hdr *sub_tlv = NULL;
+		struct br_mrp_oui_hdr *oui = NULL;
+		u8 length;
+
+		length = sizeof(*sub_opt) + sizeof(*sub_tlv) + sizeof(oui) +
+			MRP_OPT_PADDING;
+		br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_OPTION, length);
+
+		oui = skb_put(skb, sizeof(*oui));
+		memset(oui, 0x0, sizeof(*oui));
+		sub_opt = skb_put(skb, sizeof(*sub_opt));
+		memset(sub_opt, 0x0, sizeof(*sub_opt));
+
+		sub_tlv = skb_put(skb, sizeof(*sub_tlv));
+		sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR;
+
+		/* 32 bit alligment shall be ensured therefore add 2 bytes */
+		skb_put(skb, MRP_OPT_PADDING);
+	}
+
 	br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_END, 0x0);
 
 	return skb;

net/bridge/br_private_mrp.h

···
 #include "br_private.h"
 #include <uapi/linux/mrp_bridge.h>
 
+#define MRP_OPT_PADDING		0x2
+
 struct br_mrp {
 	/* list of mrp instances */
 	struct hlist_node		list;
···
 	__be16 transitions;
 	__be32 timestamp;
 } __attribute__((__packed__));
+
+struct br_mrp_oui_hdr {
+	__u8 oui[MRP_OUI_LENGTH];
+};
+
+struct br_mrp_sub_option1_hdr {
+	__u8 type;
+	__u8 data[MRP_MANUFACTURE_DATA_LENGTH];
+};
 
 #endif /* _BR_PRIVATE_MRP_H */