1 /* linux/net/inet/arp.h */
2 #ifndef _ARP_H
3 #define _ARP_H
4 
5 #include <linux/if_arp.h>
6 #include <net/neighbour.h>
7 
8 
9 extern struct neigh_table arp_tbl;
10 
arp_hashfn(u32 key,const struct net_device * dev,u32 hash_rnd)11 static inline u32 arp_hashfn(u32 key, const struct net_device *dev, u32 hash_rnd)
12 {
13 	u32 val = key ^ dev->ifindex;
14 
15 	return val * hash_rnd;
16 }
17 
__ipv4_neigh_lookup(struct net_device * dev,u32 key)18 static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
19 {
20 	struct neigh_hash_table *nht;
21 	struct neighbour *n;
22 	u32 hash_val;
23 
24 	rcu_read_lock_bh();
25 	nht = rcu_dereference_bh(arp_tbl.nht);
26 	hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
27 	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
28 	     n != NULL;
29 	     n = rcu_dereference_bh(n->next)) {
30 		if (n->dev == dev && *(u32 *)n->primary_key == key) {
31 			if (!atomic_inc_not_zero(&n->refcnt))
32 				n = NULL;
33 			break;
34 		}
35 	}
36 	rcu_read_unlock_bh();
37 
38 	return n;
39 }
40 
41 extern void	arp_init(void);
42 extern int	arp_find(unsigned char *haddr, struct sk_buff *skb);
43 extern int	arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
44 extern void     arp_send(int type, int ptype, __be32 dest_ip,
45 			 struct net_device *dev, __be32 src_ip,
46 			 const unsigned char *dest_hw,
47 			 const unsigned char *src_hw, const unsigned char *th);
48 extern int	arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
49 extern void	arp_ifdown(struct net_device *dev);
50 
51 extern struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
52 				  struct net_device *dev, __be32 src_ip,
53 				  const unsigned char *dest_hw,
54 				  const unsigned char *src_hw,
55 				  const unsigned char *target_hw);
56 extern void arp_xmit(struct sk_buff *skb);
57 int arp_invalidate(struct net_device *dev, __be32 ip);
58 
59 #endif	/* _ARP_H */
60