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
21#ifdef CONFIG_INET
22static 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
30static inline
31struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
32{
33	return NULL;
34}
35#endif
36
37static 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
50static 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 (n->confirmed != now)
61			n->confirmed = now;
62	}
63	rcu_read_unlock_bh();
64}
65
66void arp_init(void);
 
67int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
68void 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);
72int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
73void arp_ifdown(struct net_device *dev);
74
75struct 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);
80void arp_xmit(struct sk_buff *skb);
81
82#endif	/* _ARP_H */

 
 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
10extern struct neigh_table arp_tbl;
11
12static inline u32 arp_hashfn(u32 key, const struct net_device *dev, u32 hash_rnd)
13{
 
14	u32 val = key ^ hash32_ptr(dev);
15
16	return val * hash_rnd;
17}
18
 
19static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
20{
21	struct neigh_hash_table *nht = rcu_dereference_bh(arp_tbl.nht);
22	struct neighbour *n;
23	u32 hash_val;
24
25	hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
26	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
27	     n != NULL;
28	     n = rcu_dereference_bh(n->next)) {
29		if (n->dev == dev && *(u32 *)n->primary_key == key)
30			return n;
31	}
32
 
 
 
 
 
 
33	return NULL;
34}
 
35
36static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
37{
38	struct neighbour *n;
39
40	rcu_read_lock_bh();
41	n = __ipv4_neigh_lookup_noref(dev, key);
42	if (n && !atomic_inc_not_zero(&n->refcnt))
43		n = NULL;
44	rcu_read_unlock_bh();
45
46	return n;
47}
48
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
49void arp_init(void);
50int arp_find(unsigned char *haddr, struct sk_buff *skb);
51int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
52void arp_send(int type, int ptype, __be32 dest_ip,
53	      struct net_device *dev, __be32 src_ip,
54	      const unsigned char *dest_hw,
55	      const unsigned char *src_hw, const unsigned char *th);
56int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
57void arp_ifdown(struct net_device *dev);
58
59struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
60			   struct net_device *dev, __be32 src_ip,
61			   const unsigned char *dest_hw,
62			   const unsigned char *src_hw,
63			   const unsigned char *target_hw);
64void arp_xmit(struct sk_buff *skb);
65
66#endif	/* _ARP_H */