LXR linux/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
  10extern struct neigh_table arp_tbl;
  11
  12static 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
  19static 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
  36static 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
  49static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key)
  50{
  51        struct neighbour *n;
  52
  53        rcu_read_lock_bh();
  54        n = __ipv4_neigh_lookup_noref(dev, key);
  55        if (n) {
  56                unsigned long now = jiffies;
  57
  58                /* avoid dirtying neighbour */
  59                if (n->confirmed != now)
  60                        n->confirmed = now;
  61        }
  62        rcu_read_unlock_bh();
  63}
  64
  65void arp_init(void);
  66int arp_find(unsigned char *haddr, struct sk_buff *skb);
  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);
  81int arp_invalidate(struct net_device *dev, __be32 ip);
  82
  83#endif  /* _ARP_H */
  84