hsr: enhance netlink socket interface to support PRP

Parallel Redundancy Protocol (PRP) is another redundancy protocol
introduced by IEC 63439 standard. It is similar to HSR in many
aspects:-

 - Use a pair of Ethernet interfaces to created the PRP device
 - Use a 6 byte redundancy protocol part (RCT, Redundancy Check
   Trailer) similar to HSR Tag.
 - Has Link Redundancy Entity (LRE) that works with RCT to implement
   redundancy.

Key difference is that the protocol unit is a trailer instead of a
prefix as in HSR. That makes it inter-operable with tradition network
components such as bridges/switches which treat it as pad bytes,
whereas HSR nodes requires some kind of translators (Called redbox) to
talk to regular network devices. This features allows regular linux box
to be converted to a DAN-P box. DAN-P stands for Dual Attached Node - PRP
similar to DAN-H (Dual Attached Node - HSR).

Add a comment at the header/source code to explicitly state that the
driver files also handles PRP protocol as well.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 1 deletions

diff --git a/net/hsr/hsr_main.h b/net/hsr/hsr_main.h
index f74193465bf5..8cf10d67d5f9 100644
--- a/net/hsr/hsr_main.h
+++ b/net/hsr/hsr_main.h
@@ -3,6 +3,8 @@
  *
  * Author(s):
  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ *
+ * include file for HSR and PRP.
  */
 
 #ifndef __HSR_PRIVATE_H
@@ -131,6 +133,13 @@ struct hsr_port {
 	enum hsr_port_type	type;
 };
 
+/* used by driver internally to differentiate various protocols */
+enum hsr_version {
+	HSR_V0 = 0,
+	HSR_V1,
+	PRP_V1,
+};
+
 struct hsr_priv {
 	struct rcu_head		rcu_head;
 	struct list_head	ports;
@@ -141,7 +150,7 @@ struct hsr_priv {
 	int announce_count;
 	u16 sequence_nr;
 	u16 sup_sequence_nr;	/* For HSRv1 separate seq_nr for supervision */
-	u8 prot_version;	/* Indicate if HSRv0 or HSRv1. */
+	enum hsr_version prot_version;	/* Indicate if HSRv0, HSRv1 or PRPv1 */
 	spinlock_t seqnr_lock;	/* locking for sequence_nr */
 	spinlock_t list_lock;	/* locking for node list */
 	unsigned char		sup_multicast_addr[ETH_ALEN];