linux/include/net/arp.h
David S. Miller d3aaeb38c4 net: Add ->neigh_lookup() operation to dst_ops
In the future dst entries will be neigh-less.  In that environment we
need to have an easy transition point for current users of
dst->neighbour outside of the packet output fast path.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-18 00:40:17 -07:00

60 lines
1.7 KiB
C

/* linux/net/inet/arp.h */
#ifndef _ARP_H
#define _ARP_H
#include <linux/if_arp.h>
#include <net/neighbour.h>
extern struct neigh_table arp_tbl;
static inline u32 arp_hashfn(u32 key, const struct net_device *dev, u32 hash_rnd)
{
u32 val = key ^ dev->ifindex;
return val * hash_rnd;
}
static inline struct neighbour *__ipv4_neigh_lookup(struct neigh_table *tbl, struct net_device *dev, u32 key)
{
struct neigh_hash_table *nht;
struct neighbour *n;
u32 hash_val;
rcu_read_lock_bh();
nht = rcu_dereference_bh(tbl->nht);
hash_val = arp_hashfn(key, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
n != NULL;
n = rcu_dereference_bh(n->next)) {
if (n->dev == dev && *(u32 *)n->primary_key == key) {
if (!atomic_inc_not_zero(&n->refcnt))
n = NULL;
break;
}
}
rcu_read_unlock_bh();
return n;
}
extern void arp_init(void);
extern int arp_find(unsigned char *haddr, struct sk_buff *skb);
extern int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
extern 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);
extern int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
extern void arp_ifdown(struct net_device *dev);
extern 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);
extern void arp_xmit(struct sk_buff *skb);
int arp_invalidate(struct net_device *dev, __be32 ip);
#endif /* _ARP_H */