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, 31 insertions, 7 deletions

diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
index 6e14b7d22639..06c3cd988760 100644
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -4,7 +4,7 @@
  * Author(s):
  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
  *
- * Routines for handling Netlink messages for HSR.
+ * Routines for handling Netlink messages for HSR and PRP.
  */
 
 #include "hsr_netlink.h"
@@ -22,6 +22,7 @@ static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
 	[IFLA_HSR_VERSION]	= { .type = NLA_U8 },
 	[IFLA_HSR_SUPERVISION_ADDR]	= { .len = ETH_ALEN },
 	[IFLA_HSR_SEQ_NR]		= { .type = NLA_U16 },
+	[IFLA_HSR_PROTOCOL]		= { .type = NLA_U8 },
 };
 
 /* Here, it seems a netdevice has already been allocated for us, and the
@@ -31,8 +32,10 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 		       struct nlattr *tb[], struct nlattr *data[],
 		       struct netlink_ext_ack *extack)
 {
+	enum hsr_version proto_version;
+	unsigned char multicast_spec;
+	u8 proto = HSR_PROTOCOL_HSR;
 	struct net_device *link[2];
-	unsigned char multicast_spec, hsr_version;
 
 	if (!data) {
 		NL_SET_ERR_MSG_MOD(extack, "No slave devices specified");
@@ -69,18 +72,34 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 	else
 		multicast_spec = nla_get_u8(data[IFLA_HSR_MULTICAST_SPEC]);
 
+	if (data[IFLA_HSR_PROTOCOL])
+		proto = nla_get_u8(data[IFLA_HSR_PROTOCOL]);
+
+	if (proto >= HSR_PROTOCOL_MAX) {
+		NL_SET_ERR_MSG_MOD(extack, "Unsupported protocol\n");
+		return -EINVAL;
+	}
+
 	if (!data[IFLA_HSR_VERSION]) {
-		hsr_version = 0;
+		proto_version = HSR_V0;
 	} else {
-		hsr_version = nla_get_u8(data[IFLA_HSR_VERSION]);
-		if (hsr_version > 1) {
+		if (proto == HSR_PROTOCOL_PRP) {
+			NL_SET_ERR_MSG_MOD(extack, "PRP version unsupported\n");
+			return -EINVAL;
+		}
+
+		proto_version = nla_get_u8(data[IFLA_HSR_VERSION]);
+		if (proto_version > HSR_V1) {
 			NL_SET_ERR_MSG_MOD(extack,
-					   "Only versions 0..1 are supported");
+					   "Only HSR version 0/1 supported\n");
 			return -EINVAL;
 		}
 	}
 
-	return hsr_dev_finalize(dev, link, multicast_spec, hsr_version, extack);
+	if (proto == HSR_PROTOCOL_PRP)
+		proto_version = PRP_V1;
+
+	return hsr_dev_finalize(dev, link, multicast_spec, proto_version, extack);
 }
 
 static void hsr_dellink(struct net_device *dev, struct list_head *head)
@@ -102,6 +121,7 @@ static void hsr_dellink(struct net_device *dev, struct list_head *head)
 static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct hsr_priv *hsr = netdev_priv(dev);
+	u8 proto = HSR_PROTOCOL_HSR;
 	struct hsr_port *port;
 
 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
@@ -120,6 +140,10 @@ static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		    hsr->sup_multicast_addr) ||
 	    nla_put_u16(skb, IFLA_HSR_SEQ_NR, hsr->sequence_nr))
 		goto nla_put_failure;
+	if (hsr->prot_version == PRP_V1)
+		proto = HSR_PROTOCOL_PRP;
+	if (nla_put_u8(skb, IFLA_HSR_PROTOCOL, proto))
+		goto nla_put_failure;
 
 	return 0;