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
 9extern struct neigh_table arp_tbl;
10
11static 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
18static inline struct neighbour *__ipv4_neigh_lookup(struct neigh_table *tbl, 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(tbl->nht);
26	hash_val = arp_hashfn(key, dev, nht->hash_rnd) >> (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
41extern void	arp_init(void);
42extern int	arp_find(unsigned char *haddr, struct sk_buff *skb);
43extern int	arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
44extern 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);
48extern int	arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
49extern void	arp_ifdown(struct net_device *dev);
50
51extern 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);
56extern void arp_xmit(struct sk_buff *skb);
57int arp_invalidate(struct net_device *dev, __be32 ip);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
58
59#endif	/* _ARP_H */

 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 */