linux/include/net/arp.h
Eric W. Biederman 60395a20ff neigh: Factor out ___neigh_lookup_noref
While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref.  We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.

So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref.  Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function.  I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.

To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq.  So that the static size of the key would be
available.

I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:23:23 -05:00

54 lines
1.4 KiB
C

/* linux/net/inet/arp.h */
#ifndef _ARP_H
#define _ARP_H
#include <linux/if_arp.h>
#include <linux/hash.h>
#include <net/neighbour.h>
extern struct neigh_table arp_tbl;
static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd)
{
u32 key = *(const u32 *)pkey;
u32 val = key ^ hash32_ptr(dev);
return val * hash_rnd[0];
}
static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
{
return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
}
static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
{
struct neighbour *n;
rcu_read_lock_bh();
n = __ipv4_neigh_lookup_noref(dev, key);
if (n && !atomic_inc_not_zero(&n->refcnt))
n = NULL;
rcu_read_unlock_bh();
return n;
}
void arp_init(void);
int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
void arp_send(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 src_ip,
const unsigned char *dest_hw,
const unsigned char *src_hw, const unsigned char *th);
int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);
void arp_ifdown(struct net_device *dev);
struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 src_ip,
const unsigned char *dest_hw,
const unsigned char *src_hw,
const unsigned char *target_hw);
void arp_xmit(struct sk_buff *skb);
#endif /* _ARP_H */