mirror of
https://github.com/torvalds/linux.git
synced 2024-12-30 14:52:05 +00:00
25c7a6d1f9
There are common instances of the following construct : if (n->confirmed != now) n->confirmed = now; A C compiler could legally remove the conditional. Use READ_ONCE()/WRITE_ONCE() to avoid this problem. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
83 lines
2.0 KiB
C
83 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/* linux/net/inet/arp.h */
|
|
#ifndef _ARP_H
|
|
#define _ARP_H
|
|
|
|
#include <linux/if_arp.h>
|
|
#include <linux/hash.h>
|
|
#include <net/neighbour.h>
|
|
|
|
|
|
extern struct neigh_table arp_tbl;
|
|
|
|
static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd)
|
|
{
|
|
u32 key = *(const u32 *)pkey;
|
|
u32 val = key ^ hash32_ptr(dev);
|
|
|
|
return val * hash_rnd[0];
|
|
}
|
|
|
|
#ifdef CONFIG_INET
|
|
static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
|
|
{
|
|
if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
|
|
key = INADDR_ANY;
|
|
|
|
return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
|
|
}
|
|
#else
|
|
static inline
|
|
struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
|
|
{
|
|
struct neighbour *n;
|
|
|
|
rcu_read_lock_bh();
|
|
n = __ipv4_neigh_lookup_noref(dev, key);
|
|
if (n && !refcount_inc_not_zero(&n->refcnt))
|
|
n = NULL;
|
|
rcu_read_unlock_bh();
|
|
|
|
return n;
|
|
}
|
|
|
|
static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key)
|
|
{
|
|
struct neighbour *n;
|
|
|
|
rcu_read_lock_bh();
|
|
n = __ipv4_neigh_lookup_noref(dev, key);
|
|
if (n) {
|
|
unsigned long now = jiffies;
|
|
|
|
/* avoid dirtying neighbour */
|
|
if (READ_ONCE(n->confirmed) != now)
|
|
WRITE_ONCE(n->confirmed, now);
|
|
}
|
|
rcu_read_unlock_bh();
|
|
}
|
|
|
|
void arp_init(void);
|
|
int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
|
|
void arp_send(int type, int ptype, __be32 dest_ip,
|
|
struct net_device *dev, __be32 src_ip,
|
|
const unsigned char *dest_hw,
|
|
const unsigned char *src_hw, const unsigned char *th);
|
|
int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
|
|
void arp_ifdown(struct net_device *dev);
|
|
|
|
struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
|
|
struct net_device *dev, __be32 src_ip,
|
|
const unsigned char *dest_hw,
|
|
const unsigned char *src_hw,
|
|
const unsigned char *target_hw);
|
|
void arp_xmit(struct sk_buff *skb);
|
|
|
|
#endif /* _ARP_H */
|