include/net/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 <net/neighbour.h>
   7
   8
   9 extern struct neigh_table arp_tbl;
  10
  11 static 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
  18 static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
  19 {
  20         struct neigh_hash_table *nht = rcu_dereference_bh(arp_tbl.nht);
  21         struct neighbour *n;
  22         u32 hash_val;
  23
  24         hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
  25         for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
  26              n != NULL;
  27              n = rcu_dereference_bh(n->next)) {
  28                 if (n->dev == dev && *(u32 *)n->primary_key == key)
  29                         return n;
  30         }
  31
  32         return NULL;
  33 }
  34
  35 static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
  36 {
  37         struct neighbour *n;
  38
  39         rcu_read_lock_bh();
  40         n = __ipv4_neigh_lookup_noref(dev, key);
  41         if (n && !atomic_inc_not_zero(&n->refcnt))
  42                 n = NULL;
  43         rcu_read_unlock_bh();
  44
  45         return n;
  46 }
  47
  48 extern void     arp_init(void);
  49 extern int      arp_find(unsigned char *haddr, struct sk_buff *skb);
  50 extern int      arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
  51 extern void     arp_send(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, const unsigned char *th);
  55 extern int      arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
  56 extern void     arp_ifdown(struct net_device *dev);
  57
  58 extern struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
  59                                   struct net_device *dev, __be32 src_ip,
  60                                   const unsigned char *dest_hw,
  61                                   const unsigned char *src_hw,
  62                                   const unsigned char *target_hw);
  63 extern void arp_xmit(struct sk_buff *skb);
  64 int arp_invalidate(struct net_device *dev, __be32 ip);
  65
  66 #endif  /* _ARP_H */