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 <linux/hash.h>
   7 #include <net/neighbour.h>
   8
   9
  10 extern struct neigh_table arp_tbl;
  11
  12 static 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
  19 static 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
  36 static 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
  49 extern void     arp_init(void);
  50 extern int      arp_find(unsigned char *haddr, struct sk_buff *skb);
  51 extern int      arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
  52 extern void     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);
  56 extern int      arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
  57 extern void     arp_ifdown(struct net_device *dev);
  58
  59 extern struct 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);
  64 extern void arp_xmit(struct sk_buff *skb);
  65 int arp_invalidate(struct net_device *dev, __be32 ip);
  66
  67 #endif  /* _ARP_H */