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
11 extern struct neigh_table arp_tbl;
12
arp_hashfn(const void * pkey,const struct net_device * dev,u32 * hash_rnd)13 static 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
21 #ifdef CONFIG_INET
__ipv4_neigh_lookup_noref(struct net_device * dev,u32 key)22 static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
23 {
24 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
25 key = INADDR_ANY;
26
27 return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
28 }
29 #else
30 static inline
__ipv4_neigh_lookup_noref(struct net_device * dev,u32 key)31 struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
32 {
33 return NULL;
34 }
35 #endif
36
__ipv4_neigh_lookup(struct net_device * dev,u32 key)37 static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
38 {
39 struct neighbour *n;
40
41 rcu_read_lock_bh();
42 n = __ipv4_neigh_lookup_noref(dev, key);
43 if (n && !refcount_inc_not_zero(&n->refcnt))
44 n = NULL;
45 rcu_read_unlock_bh();
46
47 return n;
48 }
49
__ipv4_confirm_neigh(struct net_device * dev,u32 key)50 static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key)
51 {
52 struct neighbour *n;
53
54 rcu_read_lock_bh();
55 n = __ipv4_neigh_lookup_noref(dev, key);
56 if (n) {
57 unsigned long now = jiffies;
58
59 /* avoid dirtying neighbour */
60 if (READ_ONCE(n->confirmed) != now)
61 WRITE_ONCE(n->confirmed, now);
62 }
63 rcu_read_unlock_bh();
64 }
65
66 void arp_init(void);
67 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
68 void arp_send(int type, int ptype, __be32 dest_ip,
69 struct net_device *dev, __be32 src_ip,
70 const unsigned char *dest_hw,
71 const unsigned char *src_hw, const unsigned char *th);
72 int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
73 void arp_ifdown(struct net_device *dev);
74
75 struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
76 struct net_device *dev, __be32 src_ip,
77 const unsigned char *dest_hw,
78 const unsigned char *src_hw,
79 const unsigned char *target_hw);
80 void arp_xmit(struct sk_buff *skb);
81
82 #endif /* _ARP_H */
83
