alistair23-linux/net/batman-adv/hard-interface.h
Sven Eckelmann b4d922cfc9 batman-adv: Drop immediate batadv_hard_iface free function
It is not allowed to free the memory of an object which is part of a list
which is protected by rcu-read-side-critical sections without making sure
that no other context is accessing the object anymore. This usually happens
by removing the references to this object and then waiting until the rcu
grace period is over and no one (allowedly) accesses it anymore.

But the _now functions ignore this completely. They free the object
directly even when a different context still tries to access it. This has
to be avoided and thus these functions must be removed and all functions
have to use batadv_hardif_free_ref.

Fixes: 89652331c0 ("batman-adv: split tq information in neigh_node struct")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
2016-01-16 22:49:51 +08:00

97 lines
2.8 KiB
C

/* Copyright (C) 2007-2015 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _NET_BATMAN_ADV_HARD_INTERFACE_H_
#define _NET_BATMAN_ADV_HARD_INTERFACE_H_
#include "main.h"
#include <linux/atomic.h>
#include <linux/compiler.h>
#include <linux/notifier.h>
#include <linux/rcupdate.h>
#include <linux/stddef.h>
#include <linux/types.h>
struct net_device;
enum batadv_hard_if_state {
BATADV_IF_NOT_IN_USE,
BATADV_IF_TO_BE_REMOVED,
BATADV_IF_INACTIVE,
BATADV_IF_ACTIVE,
BATADV_IF_TO_BE_ACTIVATED,
BATADV_IF_I_WANT_YOU,
};
/**
* enum batadv_hard_if_cleanup - Cleanup modi for soft_iface after slave removal
* @BATADV_IF_CLEANUP_KEEP: Don't automatically delete soft-interface
* @BATADV_IF_CLEANUP_AUTO: Delete soft-interface after last slave was removed
*/
enum batadv_hard_if_cleanup {
BATADV_IF_CLEANUP_KEEP,
BATADV_IF_CLEANUP_AUTO,
};
extern struct notifier_block batadv_hard_if_notifier;
bool batadv_is_wifi_netdev(struct net_device *net_device);
bool batadv_is_wifi_iface(int ifindex);
struct batadv_hard_iface*
batadv_hardif_get_by_netdev(const struct net_device *net_dev);
int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
const char *iface_name);
void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
enum batadv_hard_if_cleanup autodel);
void batadv_hardif_remove_interfaces(void);
int batadv_hardif_min_mtu(struct net_device *soft_iface);
void batadv_update_min_mtu(struct net_device *soft_iface);
void batadv_hardif_free_rcu(struct rcu_head *rcu);
/**
* batadv_hardif_free_ref - decrement the hard interface refcounter and
* possibly free it
* @hard_iface: the hard interface to free
*/
static inline void
batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface)
{
if (atomic_dec_and_test(&hard_iface->refcount))
call_rcu(&hard_iface->rcu, batadv_hardif_free_rcu);
}
static inline struct batadv_hard_iface *
batadv_primary_if_get_selected(struct batadv_priv *bat_priv)
{
struct batadv_hard_iface *hard_iface;
rcu_read_lock();
hard_iface = rcu_dereference(bat_priv->primary_if);
if (!hard_iface)
goto out;
if (!atomic_inc_not_zero(&hard_iface->refcount))
hard_iface = NULL;
out:
rcu_read_unlock();
return hard_iface;
}
#endif /* _NET_BATMAN_ADV_HARD_INTERFACE_H_ */