batman-adv: Mark debugfs functionality as deprecated

CONFIG_BATMAN_ADV_DEBUGFS is disabled by default because debugfs is not
supported for batman-adv interfaces in any non-default netns. Any remaining
users of this interface should still be informed about the deprecation and
the generic netlink alternative.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

net/batman-adv/debugfs.c

@@ -47,8 +47,24 @@
 
 static struct dentry *batadv_debugfs;
 
+/**
+ * batadv_debugfs_deprecated() - Log use of deprecated batadv debugfs access
+ * @file: file which was accessed
+ * @alt: explanation what can be used as alternative
+ */
+void batadv_debugfs_deprecated(struct file *file, const char *alt)
+{
+	struct dentry *dentry = file_dentry(file);
+	const char *name = dentry->d_name.name;
+
+	pr_warn_ratelimited(DEPRECATED "%s (pid %d) Use of debugfs file \"%s\".\n%s",
+			    current->comm, task_pid_nr(current), name, alt);
+}
+
 static int batadv_algorithms_open(struct inode *inode, struct file *file)
 {
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_ROUTING_ALGOS instead\n");
 	return single_open(file, batadv_algo_seq_print_text, NULL);
 }
 
@@ -56,6 +72,8 @@ static int neighbors_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_NEIGHBORS instead\n");
 	return single_open(file, batadv_hardif_neigh_seq_print_text, net_dev);
 }
 
@@ -63,6 +81,8 @@ static int batadv_originators_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_ORIGINATORS instead\n");
 	return single_open(file, batadv_orig_seq_print_text, net_dev);
 }
 
@@ -79,6 +99,8 @@ static int batadv_originators_hardif_open(struct inode *inode,
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_HARDIFS instead\n");
 	return single_open(file, batadv_orig_hardif_seq_print_text, net_dev);
 }
 
@@ -86,6 +108,8 @@ static int batadv_gateways_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_GATEWAYS instead\n");
 	return single_open(file, batadv_gw_client_seq_print_text, net_dev);
 }
 
@@ -93,6 +117,8 @@ static int batadv_transtable_global_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_TRANSTABLE_GLOBAL instead\n");
 	return single_open(file, batadv_tt_global_seq_print_text, net_dev);
 }
 
@@ -101,6 +127,8 @@ static int batadv_bla_claim_table_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_BLA_CLAIM instead\n");
 	return single_open(file, batadv_bla_claim_table_seq_print_text,
 			   net_dev);
 }
@@ -110,6 +138,8 @@ static int batadv_bla_backbone_table_open(struct inode *inode,
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_BLA_BACKBONE instead\n");
 	return single_open(file, batadv_bla_backbone_table_seq_print_text,
 			   net_dev);
 }
@@ -128,6 +158,8 @@ static int batadv_dat_cache_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_DAT_CACHE instead\n");
 	return single_open(file, batadv_dat_cache_seq_print_text, net_dev);
 }
 #endif
@@ -136,6 +168,8 @@ static int batadv_transtable_local_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_TRANSTABLE_LOCAL instead\n");
 	return single_open(file, batadv_tt_local_seq_print_text, net_dev);
 }
 
@@ -149,6 +183,7 @@ static int batadv_nc_nodes_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file, "");
 	return single_open(file, batadv_nc_nodes_seq_print_text, net_dev);
 }
 #endif
@@ -165,6 +200,8 @@ static int batadv_mcast_flags_open(struct inode *inode, struct file *file)
 {
 	struct net_device *net_dev = (struct net_device *)inode->i_private;
 
+	batadv_debugfs_deprecated(file,
+				  "Use genl command BATADV_CMD_GET_MCAST_FLAGS instead\n");
 	return single_open(file, batadv_mcast_flags_seq_print_text, net_dev);
 }
 #endif

net/batman-adv/debugfs.h

@@ -21,12 +21,14 @@
 
 #include "main.h"
 
+struct file;
 struct net_device;
 
 #define BATADV_DEBUGFS_SUBDIR "batman_adv"
 
 #if IS_ENABLED(CONFIG_BATMAN_ADV_DEBUGFS)
 
+void batadv_debugfs_deprecated(struct file *file, const char *alt);
 void batadv_debugfs_init(void);
 void batadv_debugfs_destroy(void);
 int batadv_debugfs_add_meshif(struct net_device *dev);
@@ -38,6 +40,10 @@ void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface);
 
 #else
 
+static inline void batadv_debugfs_deprecated(struct file *file, const char *alt)
+{
+}
+
 static inline void batadv_debugfs_init(void)
 {
 }

net/batman-adv/icmp_socket.c

@@ -47,6 +47,7 @@
 #include <linux/wait.h>
 #include <uapi/linux/batadv_packet.h>
 
+#include "debugfs.h"
 #include "hard-interface.h"
 #include "log.h"
 #include "originator.h"
@@ -74,6 +75,8 @@ static int batadv_socket_open(struct inode *inode, struct file *file)
 	if (!try_module_get(THIS_MODULE))
 		return -EBUSY;
 
+	batadv_debugfs_deprecated(file, "");
+
 	nonseekable_open(inode, file);
 
 	socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);

net/batman-adv/log.c

@@ -40,6 +40,8 @@
 #include <linux/wait.h>
 #include <stdarg.h>
 
+#include "debugfs.h"
+
 #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
 
 static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
@@ -115,6 +117,8 @@ static int batadv_log_open(struct inode *inode, struct file *file)
 	if (!try_module_get(THIS_MODULE))
 		return -EBUSY;
 
+	batadv_debugfs_deprecated(file, "");
+
 	nonseekable_open(inode, file);
 	file->private_data = inode->i_private;
 	return 0;