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
  11 extern struct neigh_table arp_tbl;
  12
  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 static 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
  29 static 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
  42 static 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
  58 void arp_init(void);
  59 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
  60 void 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);
  64 int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
  65 void arp_ifdown(struct net_device *dev);
  66
  67 struct 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);
  72 void arp_xmit(struct sk_buff *skb);
  73
  74 #endif  /* _ARP_H */