Re: [PATCH net-next 07/11] net: dsa: debugfs: add port fdb

Add a debug filesystem "fdb" entry to query a port's hardware FDB
entries through the .port_fdb_dump switch operation.

This is really convenient to query directly the hardware or inspect DSA
or CPU links, since these ports are not exposed to userspace.

    # cat port1/fdb
    vid 0    12:34:56:78:90:ab    static    unicast

Signed-off-by: Vivien Didelot <redacted>
---
 net/dsa/debugfs.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/net/dsa/debugfs.c b/net/dsa/debugfs.c
index 012fcf466cc1..8204c62dc9c1 100644
--- a/net/dsa/debugfs.c
+++ b/net/dsa/debugfs.c

@@ -10,6 +10,7 @@
  */
 
 #include <linux/debugfs.h>
+#include <linux/etherdevice.h>
 #include <linux/seq_file.h>
 
 #include "dsa_priv.h"

@@ -109,6 +110,36 @@ static int dsa_debugfs_create_file(struct dsa_switch *ds, struct dentry *dir,
 	return 0;
 }
 
+static int dsa_debugfs_fdb_dump_cb(const unsigned char *addr, u16 vid,
+				   bool is_static, void *data)
+{
+	struct seq_file *seq = data;
+	int i;

+
+	seq_printf(seq, "vid %d", vid);
+	for (i = 0; i < ETH_ALEN; i++)
+		seq_printf(seq, "%s%02x", i ? ":" : "    ", addr[i]);