1/* SPDX-License-Identifier: GPL-2.0 */
2/* linux/net/inet/arp.h */
3#ifndef _ARP_H
4#define _ARP_H
5
6#include <linux/if_arp.h>
7#include <linux/hash.h>
8#include <net/neighbour.h>
9
10
11extern struct neigh_table arp_tbl;
12
13static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd)
14{
15 u32 key = *(const u32 *)pkey;
16 u32 val = key ^ hash32_ptr(dev);
17
18 return val * hash_rnd[0];
19}
20
21static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
22{
23 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
24 key = INADDR_ANY;
25
26 return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
27}
28
29static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
30{
31 struct neighbour *n;
32
33 rcu_read_lock_bh();
34 n = __ipv4_neigh_lookup_noref(dev, key);
35 if (n && !refcount_inc_not_zero(&n->refcnt))
36 n = NULL;
37 rcu_read_unlock_bh();
38
39 return n;
40}
41
42static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key)
43{
44 struct neighbour *n;
45
46 rcu_read_lock_bh();
47 n = __ipv4_neigh_lookup_noref(dev, key);
48 if (n) {
49 unsigned long now = jiffies;
50
51 /* avoid dirtying neighbour */
52 if (n->confirmed != now)
53 n->confirmed = now;
54 }
55 rcu_read_unlock_bh();
56}
57
58void arp_init(void);
59int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
60void arp_send(int type, int ptype, __be32 dest_ip,
61 struct net_device *dev, __be32 src_ip,
62 const unsigned char *dest_hw,
63 const unsigned char *src_hw, const unsigned char *th);
64int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
65void arp_ifdown(struct net_device *dev);
66
67struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
68 struct net_device *dev, __be32 src_ip,
69 const unsigned char *dest_hw,
70 const unsigned char *src_hw,
71 const unsigned char *target_hw);
72void arp_xmit(struct sk_buff *skb);
73
74#endif /* _ARP_H */
75