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Commit 36dc621c authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Simon Wunderlich
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batman-adv: Fix debugfs path for renamed hardif 



batman-adv is creating special debugfs directories in the init
net_namespace for each valid hard-interface (net_device). But it is
possible to rename a net_device to a completely different name then the
original one.

It can therefore happen that a user registers a new net_device which gets
the name "wlan0" assigned by default. batman-adv is also adding a new
directory under $debugfs/batman-adv/ with the name "wlan0".

The user then decides to rename this device to "wl_pri" and registers a
different device. The kernel may now decide to use the name "wlan0" again
for this new device. batman-adv will detect it as a valid net_device and
tries to create a directory with the name "wlan0" under
$debugfs/batman-adv/. But there already exists one with this name under
this path and thus this fails. batman-adv will detect a problem and
rollback the registering of this device.

batman-adv must therefore take care of renaming the debugfs directories
for hard-interfaces whenever it detects such a net_device rename.

Fixes: 5bc7c1eb ("batman-adv: add debugfs structure for information per interface")
Reported-by: default avatarJohn Soros <sorosj@gmail.com>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent 9713cb0c

net/batman-adv/debugfs.c

+20 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include "debugfs.h"

#include "main.h"



#include <linux/dcache.h>

#include <linux/debugfs.h>

#include <linux/err.h>

#include <linux/errno.h>
@@ -343,6 +344,25 @@ int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface) 
	return -ENOMEM;

}



/**

 * batadv_debugfs_rename_hardif() - Fix debugfs path for renamed hardif

 * @hard_iface: hard interface which was renamed

 */

void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface)

{

	const char *name = hard_iface->net_dev->name;

	struct dentry *dir;

	struct dentry *d;



	dir = hard_iface->debug_dir;

	if (!dir)

		return;



	d = debugfs_rename(dir->d_parent, dir, dir->d_parent, name);

	if (!d)

		pr_err("Can't rename debugfs dir to %s\n", name);

}



/**

 * batadv_debugfs_del_hardif() - delete the base directory for a hard interface

 *  in debugfs.

net/batman-adv/debugfs.h

+6 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ void batadv_debugfs_destroy(void); 
int batadv_debugfs_add_meshif(struct net_device *dev);

void batadv_debugfs_del_meshif(struct net_device *dev);

int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface);

void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface);

void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface);



#else
@@ -59,6 +60,11 @@ int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface) 
	return 0;

}



static inline

void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface)

{

}



static inline

void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface)

{

net/batman-adv/hard-interface.c

+3 −0
Original line number Diff line number Diff line
@@ -1051,6 +1051,9 @@ static int batadv_hard_if_event(struct notifier_block *this, 
		if (batadv_is_wifi_hardif(hard_iface))

			hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;

		break;

	case NETDEV_CHANGENAME:

		batadv_debugfs_rename_hardif(hard_iface);

		break;

	default:

		break;

	}