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Commit 3769cffb authored by David Miller's avatar David Miller Committed by David S. Miller
Browse files

ipv4: Inline neigh binding. 



Get rid of all of the useless and costly indirection
by doing the neigh hash table lookup directly inside
of the neighbour binding.

Rename from arp_bind_neighbour to rt_bind_neighbour.

Use new helpers {__,}ipv4_neigh_lookup()

In rt_bind_neighbour() get rid of useless tests which
are never true in the context this function is called,
namely dev is never NULL and the dst->neighbour is
always NULL.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e5b1de1f

include/net/arp.h

+32 −1
Original line number Diff line number Diff line
@@ -15,6 +15,38 @@ static inline u32 arp_hashfn(u32 key, const struct net_device *dev, u32 hash_rnd 
	return val * hash_rnd;

}



static inline struct neighbour *__ipv4_neigh_lookup(struct neigh_table *tbl, struct net_device *dev, u32 key)

{

	struct neigh_hash_table *nht;

	struct neighbour *n;

	u32 hash_val;



	rcu_read_lock_bh();

	nht = rcu_dereference_bh(tbl->nht);

	hash_val = arp_hashfn(key, dev, nht->hash_rnd) >> (32 - nht->hash_shift);

	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);

	     n != NULL;

	     n = rcu_dereference_bh(n->next)) {

		if (n->dev == dev && *(u32 *)n->primary_key == key) {

			if (!atomic_inc_not_zero(&n->refcnt))

				n = NULL;

			break;

		}

	}

	rcu_read_unlock_bh();



	return n;

}



static inline struct neighbour *ipv4_neigh_lookup(struct neigh_table *tbl, struct net_device *dev, const __be32 *pkey)

{

	struct neighbour *n = __ipv4_neigh_lookup(tbl, dev,

						  *(__force u32 *)pkey);

	if (n)

		return n;

	return neigh_create(tbl, pkey, dev);

}



extern void	arp_init(void);

extern int	arp_find(unsigned char *haddr, struct sk_buff *skb);

extern int	arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
@@ -22,7 +54,6 @@ extern 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);

extern int	arp_bind_neighbour(struct dst_entry *dst);

extern int	arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);

extern void	arp_ifdown(struct net_device *dev);

net/ipv4/arp.c

+0 −24
Original line number Diff line number Diff line
@@ -517,30 +517,6 @@ EXPORT_SYMBOL(arp_find); 


/* END OF OBSOLETE FUNCTIONS */



int arp_bind_neighbour(struct dst_entry *dst)

{

	struct net_device *dev = dst->dev;

	struct neighbour *n = dst->neighbour;



	if (dev == NULL)

		return -EINVAL;

	if (n == NULL) {

		__be32 nexthop = ((struct rtable *)dst)->rt_gateway;

		if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))

			nexthop = 0;

		n = __neigh_lookup_errno(

#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)

					 dev->type == ARPHRD_ATM ?

					 clip_tbl_hook :

#endif

					 &arp_tbl, &nexthop, dev);

		if (IS_ERR(n))

			return PTR_ERR(n);

		dst->neighbour = n;

	}

	return 0;

}



/*

 * Check if we can use proxy ARP for this path

 */

net/ipv4/route.c

+27 −3
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ 
#ifdef CONFIG_SYSCTL

#include <linux/sysctl.h>

#endif

#include <net/atmclip.h>



#define RT_FL_TOS(oldflp4) \

    ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
@@ -1006,6 +1007,29 @@ static int slow_chain_length(const struct rtable *head) 
	return length >> FRACT_BITS;

}



static int rt_bind_neighbour(struct rtable *rt)

{

	static const __be32 inaddr_any = 0;

	struct net_device *dev = rt->dst.dev;

	struct neigh_table *tbl = &arp_tbl;

	const __be32 *nexthop;

	struct neighbour *n;



#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)

	if (dev->type == ARPHRD_ATM)

		tbl = clip_tbl_hook;

#endif

	nexthop = &rt->rt_gateway;

	if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))

		nexthop = &inaddr_any;

	n = ipv4_neigh_lookup(tbl, dev, nexthop);

	if (IS_ERR(n))

		return PTR_ERR(n);

	rt->dst.neighbour = n;



	return 0;

}



static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,

				     struct sk_buff *skb, int ifindex)

{
@@ -1042,7 +1066,7 @@ restart: 


		rt->dst.flags |= DST_NOCACHE;

		if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {

			int err = arp_bind_neighbour(&rt->dst);

			int err = rt_bind_neighbour(rt);

			if (err) {

				if (net_ratelimit())

					printk(KERN_WARNING
@@ -1138,7 +1162,7 @@ restart: 
	   route or unicast forwarding path.

	 */

	if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {

		int err = arp_bind_neighbour(&rt->dst);

		int err = rt_bind_neighbour(rt);

		if (err) {

			spin_unlock_bh(rt_hash_lock_addr(hash));
@@ -1599,7 +1623,7 @@ static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) 
	rt->dst.neighbour = NULL;



	rt->rt_gateway = peer->redirect_learned.a4;

	if (arp_bind_neighbour(&rt->dst) ||

	if (rt_bind_neighbour(rt) ||

	    !(rt->dst.neighbour->nud_state & NUD_VALID)) {

		if (rt->dst.neighbour)

			neigh_event_send(rt->dst.neighbour, NULL);