LXR linux/include/net/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
  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 */
  83