net: hsr: introduce protocol specific function pointers

As a preparatory patch to introduce support for PRP protocol, add a
protocol ops ptr in the private hsr structure to hold function
pointers as some of the functions at protocol level packet
handling is different for HSR vs PRP. It is expected that PRP will
add its of set of functions for protocol handling. Modify existing
hsr_announce() function to call proto_ops->send_sv_frame() to send
supervision frame for HSR. This is expected to be different for PRP.
So introduce a ops function ptr, send_sv_frame() for the same and
initialize it to send_hsr_supervsion_frame(). Modify hsr_announce()
to call proto_ops->send_sv_frame().

Signed-off-by: Murali Karicheri <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/hsr/hsr_device.c

···
 	.parse	 = eth_header_parse,
 };
 
-static struct sk_buff *hsr_init_skb(struct hsr_port *master, u8 hsr_ver)
+static struct sk_buff *hsr_init_skb(struct hsr_port *master, u16 proto)
 {
 	struct hsr_priv *hsr = master->hsr;
 	struct sk_buff *skb;
···
 
 	skb_reserve(skb, hlen);
 	skb->dev = master->dev;
-	skb->protocol = htons(hsr_ver ? ETH_P_HSR : ETH_P_PRP);
+	skb->protocol = htons(proto);
 	skb->priority = TC_PRIO_CONTROL;
 
-	if (dev_hard_header(skb, skb->dev, (hsr_ver ? ETH_P_HSR : ETH_P_PRP),
+	if (dev_hard_header(skb, skb->dev, proto,
 			    hsr->sup_multicast_addr,
 			    skb->dev->dev_addr, skb->len) <= 0)
 		goto out;
···
 }
 
 static void send_hsr_supervision_frame(struct hsr_port *master,
-				       u8 type, u8 hsr_ver)
+				       unsigned long *interval)
 {
+	struct hsr_priv *hsr = master->hsr;
+	__u8 type = HSR_TLV_LIFE_CHECK;
+	struct hsr_tag *hsr_tag = NULL;
 	struct hsr_sup_payload *hsr_sp;
 	struct hsr_sup_tag *hsr_stag;
-	struct hsr_tag *hsr_tag;
 	unsigned long irqflags;
 	struct sk_buff *skb;
+	u16 proto;
 
-	skb = hsr_init_skb(master, hsr_ver);
+	*interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
+	if (hsr->announce_count < 3 && hsr->prot_version == 0) {
+		type = HSR_TLV_ANNOUNCE;
+		*interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
+		hsr->announce_count++;
+	}
+
+	if (!hsr->prot_version)
+		proto = ETH_P_PRP;
+	else
+		proto = ETH_P_HSR;
+
+	skb = hsr_init_skb(master, proto);
 	if (!skb) {
 		WARN_ONCE(1, "HSR: Could not send supervision frame\n");
 		return;
 	}
 
-	if (hsr_ver > 0) {
+	if (hsr->prot_version > 0) {
 		hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
 		hsr_tag->encap_proto = htons(ETH_P_PRP);
 		set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
 	}
 
 	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
-	set_hsr_stag_path(hsr_stag, (hsr_ver ? 0x0 : 0xf));
-	set_hsr_stag_HSR_ver(hsr_stag, hsr_ver);
+	set_hsr_stag_path(hsr_stag, (hsr->prot_version ? 0x0 : 0xf));
+	set_hsr_stag_HSR_ver(hsr_stag, hsr->prot_version);
 
 	/* From HSRv1 on we have separate supervision sequence numbers. */
 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
-	if (hsr_ver > 0) {
-		hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
-		hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
-		master->hsr->sup_sequence_nr++;
-		master->hsr->sequence_nr++;
+	if (hsr->prot_version > 0) {
+		hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr);
+		hsr->sup_sequence_nr++;
+		hsr_tag->sequence_nr = htons(hsr->sequence_nr);
+		hsr->sequence_nr++;
 	} else {
-		hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
-		master->hsr->sequence_nr++;
+		hsr_stag->sequence_nr = htons(hsr->sequence_nr);
+		hsr->sequence_nr++;
 	}
 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
 
 	hsr_stag->HSR_TLV_type = type;
 	/* TODO: Why 12 in HSRv0? */
-	hsr_stag->HSR_TLV_length =
-				hsr_ver ? sizeof(struct hsr_sup_payload) : 12;
+	hsr_stag->HSR_TLV_length = hsr->prot_version ?
+				sizeof(struct hsr_sup_payload) : 12;
 
 	/* Payload: MacAddressA */
 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
···
 
 	rcu_read_lock();
 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
-
-	if (hsr->announce_count < 3 && hsr->prot_version == 0) {
-		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
-					   hsr->prot_version);
-		hsr->announce_count++;
-
-		interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
-	} else {
-		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
-					   hsr->prot_version);
-
-		interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
-	}
+	hsr->proto_ops->send_sv_frame(master, &interval);
 
 	if (is_admin_up(master->dev))
 		mod_timer(&hsr->announce_timer, jiffies + interval);
···
 
 static struct device_type hsr_type = {
 	.name = "hsr",
+};
+
+static struct hsr_proto_ops hsr_ops = {
+	.send_sv_frame = send_hsr_supervision_frame,
 };
 
 void hsr_dev_setup(struct net_device *dev)
···
 	if (protocol_version == PRP_V1)
 		return -EPROTONOSUPPORT;
 
+	hsr->proto_ops = &hsr_ops;
 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
 	res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
 				   slave[1]->dev_addr);

net/hsr/hsr_main.h

···
 	PRP_V1,
 };
 
+struct hsr_proto_ops {
+	/* format and send supervision frame */
+	void (*send_sv_frame)(struct hsr_port *port, unsigned long *interval);
+};
+
 struct hsr_priv {
 	struct rcu_head		rcu_head;
 	struct list_head	ports;
···
 	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 */
+	struct hsr_proto_ops	*proto_ops;
 	unsigned char		sup_multicast_addr[ETH_ALEN];
 #ifdef	CONFIG_DEBUG_FS
 	struct dentry *node_tbl_root;