xref: /openbmc/linux/include/net/arp.h (revision bb0eb050)
1 /* linux/net/inet/arp.h */
2 #ifndef _ARP_H
3 #define _ARP_H
4 
5 #include <linux/if_arp.h>
6 #include <linux/hash.h>
7 #include <net/neighbour.h>
8 
9 
10 extern struct neigh_table arp_tbl;
11 
12 static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd)
13 {
14 	u32 key = *(const u32 *)pkey;
15 	u32 val = key ^ hash32_ptr(dev);
16 
17 	return val * hash_rnd[0];
18 }
19 
20 static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
21 {
22 	return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
23 }
24 
25 static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
26 {
27 	struct neighbour *n;
28 
29 	rcu_read_lock_bh();
30 	n = __ipv4_neigh_lookup_noref(dev, key);
31 	if (n && !atomic_inc_not_zero(&n->refcnt))
32 		n = NULL;
33 	rcu_read_unlock_bh();
34 
35 	return n;
36 }
37 
38 static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key)
39 {
40 	struct neighbour *n;
41 
42 	rcu_read_lock_bh();
43 	n = __ipv4_neigh_lookup_noref(dev, key);
44 	if (n) {
45 		unsigned long now = jiffies;
46 
47 		/* avoid dirtying neighbour */
48 		if (n->confirmed != now)
49 			n->confirmed = now;
50 	}
51 	rcu_read_unlock_bh();
52 }
53 
54 void arp_init(void);
55 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
56 void arp_send(int type, int ptype, __be32 dest_ip,
57 	      struct net_device *dev, __be32 src_ip,
58 	      const unsigned char *dest_hw,
59 	      const unsigned char *src_hw, const unsigned char *th);
60 int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
61 void arp_ifdown(struct net_device *dev);
62 
63 struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
64 			   struct net_device *dev, __be32 src_ip,
65 			   const unsigned char *dest_hw,
66 			   const unsigned char *src_hw,
67 			   const unsigned char *target_hw);
68 void arp_xmit(struct sk_buff *skb);
69 
70 #endif	/* _ARP_H */
71