net: hsr: add debugfs support for display node list

This adds a debugfs interface to allow display the nodes learned
by the hsr master.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_HSR)	+= hsr.o
 
 hsr-y			:= hsr_main.o hsr_framereg.o hsr_device.o \
 			   hsr_netlink.o hsr_slave.o hsr_forward.o
+hsr-$(CONFIG_DEBUG_FS) += hsr_prp_debugfs.o

net/hsr/hsr_device.c

@@ -354,6 +354,8 @@ static void hsr_dev_destroy(struct net_device *hsr_dev)
 
 	hsr = netdev_priv(hsr_dev);
 
+	hsr_prp_debugfs_term(hsr);
+
 	rtnl_lock();
 	hsr_for_each_port(hsr, port)
 		hsr_del_port(port);
@@ -483,6 +485,9 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 		goto fail;
 
 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
+	res = hsr_prp_debugfs_init(hsr);
+	if (res)
+		goto fail;
 
 	return 0;
 

net/hsr/hsr_framereg.c

@@ -18,18 +18,6 @@
 #include "hsr_framereg.h"
 #include "hsr_netlink.h"
 
-struct hsr_node {
-	struct list_head	mac_list;
-	unsigned char		macaddress_A[ETH_ALEN];
-	unsigned char		macaddress_B[ETH_ALEN];
-	/* Local slave through which AddrB frames are received from this node */
-	enum hsr_port_type	addr_B_port;
-	unsigned long		time_in[HSR_PT_PORTS];
-	bool			time_in_stale[HSR_PT_PORTS];
-	u16			seq_out[HSR_PT_PORTS];
-	struct rcu_head		rcu_head;
-};
-
 /*	TODO: use hash lists for mac addresses (linux/jhash.h)?    */
 
 /* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,

net/hsr/hsr_framereg.h

@@ -48,4 +48,16 @@ int hsr_get_node_data(struct hsr_priv *hsr,
 		      int *if2_age,
 		      u16 *if2_seq);
 
+struct hsr_node {
+	struct list_head	mac_list;
+	unsigned char		macaddress_A[ETH_ALEN];
+	unsigned char		macaddress_B[ETH_ALEN];
+	/* Local slave through which AddrB frames are received from this node */
+	enum hsr_port_type	addr_B_port;
+	unsigned long		time_in[HSR_PT_PORTS];
+	bool			time_in_stale[HSR_PT_PORTS];
+	u16			seq_out[HSR_PT_PORTS];
+	struct rcu_head		rcu_head;
+};
+
 #endif /* __HSR_FRAMEREG_H */

net/hsr/hsr_main.h

@@ -163,6 +163,10 @@ struct hsr_priv {
 	u8 prot_version;		/* Indicate if HSRv0 or HSRv1. */
 	spinlock_t seqnr_lock;			/* locking for sequence_nr */
 	unsigned char		sup_multicast_addr[ETH_ALEN];
+#ifdef	CONFIG_DEBUG_FS
+	struct dentry *node_tbl_root;
+	struct dentry *node_tbl_file;
+#endif
 };
 
 #define hsr_for_each_port(hsr, port) \
@@ -179,4 +183,17 @@ static inline u16 hsr_get_skb_sequence_nr(struct sk_buff *skb)
 	return ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
 }
 
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+int hsr_prp_debugfs_init(struct hsr_priv *priv);
+void hsr_prp_debugfs_term(struct hsr_priv *priv);
+#else
+static inline int hsr_prp_debugfs_init(struct hsr_priv *priv)
+{
+	return 0;
+}
+
+static inline void hsr_prp_debugfs_term(struct hsr_priv *priv)
+{}
+#endif
+
 #endif /*  __HSR_PRIVATE_H */

net/hsr/hsr_prp_debugfs.c

+/*
+ * hsr_prp_debugfs code
+ * Copyright (C) 2017 Texas Instruments Incorporated
+ *
+ * Author(s):
+ *	Murali Karicheri <m-karicheri2@ti.com?
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/debugfs.h>
+#include "hsr_main.h"
+#include "hsr_framereg.h"
+
+static void print_mac_address(struct seq_file *sfp, unsigned char *mac)
+{
+	seq_printf(sfp, "%02x:%02x:%02x:%02x:%02x:%02x:",
+		   mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+}
+
+/* hsr_prp_node_table_show - Formats and prints node_table entries */
+static int
+hsr_prp_node_table_show(struct seq_file *sfp, void *data)
+{
+	struct hsr_priv *priv = (struct hsr_priv *)sfp->private;
+	struct hsr_node *node;
+
+	seq_puts(sfp, "Node Table entries\n");
+	seq_puts(sfp, "MAC-Address-A,   MAC-Address-B, time_in[A], ");
+	seq_puts(sfp, "time_in[B], Address-B port\n");
+	rcu_read_lock();
+	list_for_each_entry_rcu(node, &priv->node_db, mac_list) {
+		/* skip self node */
+		if (hsr_addr_is_self(priv, node->macaddress_A))
+			continue;
+		print_mac_address(sfp, &node->macaddress_A[0]);
+		seq_puts(sfp, " ");
+		print_mac_address(sfp, &node->macaddress_B[0]);
+		seq_printf(sfp, "0x%lx, ", node->time_in[HSR_PT_SLAVE_A]);
+		seq_printf(sfp, "0x%lx ", node->time_in[HSR_PT_SLAVE_B]);
+		seq_printf(sfp, "0x%x\n", node->addr_B_port);
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/* hsr_prp_node_table_open - Open the node_table file
+ *
+ * Description:
+ * This routine opens a debugfs file node_table of specific hsr device
+ */
+static int
+hsr_prp_node_table_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, hsr_prp_node_table_show, inode->i_private);
+}
+
+static const struct file_operations hsr_prp_fops = {
+	.owner	= THIS_MODULE,
+	.open	= hsr_prp_node_table_open,
+	.read	= seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+/* hsr_prp_debugfs_init - create hsr-prp node_table file for dumping
+ * the node table
+ *
+ * Description:
+ * When debugfs is configured this routine sets up the node_table file per
+ * hsr/prp device for dumping the node_table entries
+ */
+int hsr_prp_debugfs_init(struct hsr_priv *priv)
+{
+	int rc = -1;
+	struct dentry *de = NULL;
+
+	de = debugfs_create_dir("hsr", NULL);
+	if (!de) {
+		pr_err("Cannot create hsr-prp debugfs root\n");
+		return rc;
+	}
+
+	priv->node_tbl_root = de;
+
+	de = debugfs_create_file("node_table", S_IFREG | 0444,
+				 priv->node_tbl_root, priv,
+				 &hsr_prp_fops);
+	if (!de) {
+		pr_err("Cannot create hsr-prp node_table directory\n");
+		return rc;
+	}
+	priv->node_tbl_file = de;
+	rc = 0;
+
+	return rc;
+}
+
+/* hsr_prp_debugfs_term - Tear down debugfs intrastructure
+ *
+ * Description:
+ * When Debufs is configured this routine removes debugfs file system
+ * elements that are specific to hsr-prp
+ */
+void
+hsr_prp_debugfs_term(struct hsr_priv *priv)
+{
+	debugfs_remove(priv->node_tbl_file);
+	priv->node_tbl_file = NULL;
+	debugfs_remove(priv->node_tbl_root);
+	priv->node_tbl_root = NULL;
+}