Commit fd23c3b3 authored by David S. Miller's avatar David S. Miller
Browse files

ipv4: Add hash table of interface addresses. 



This will be used to optimize __ip_dev_find() and friends.

With help from Eric Dumazet.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1cbb1a61

include/linux/inetdevice.h

+1 −0
Original line number Diff line number Diff line
@@ -144,6 +144,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev) 
#define IN_DEV_ARP_NOTIFY(in_dev)	IN_DEV_MAXCONF((in_dev), ARP_NOTIFY)



struct in_ifaddr {

	struct hlist_node	hash;

	struct in_ifaddr	*ifa_next;

	struct in_device	*ifa_dev;

	struct rcu_head		rcu_head;

net/ipv4/devinet.c

+45 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 
#include <linux/inetdevice.h>

#include <linux/igmp.h>

#include <linux/slab.h>

#include <linux/hash.h>

#ifdef CONFIG_SYSCTL

#include <linux/sysctl.h>

#endif
@@ -92,6 +93,38 @@ static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = { 
	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },

};



/* inet_addr_hash's shifting is dependent upon this IN4_ADDR_HSIZE

 * value.  So if you change this define, make appropriate changes to

 * inet_addr_hash as well.

 */

#define IN4_ADDR_HSIZE	256

static struct hlist_head inet_addr_lst[IN4_ADDR_HSIZE];

static DEFINE_SPINLOCK(inet_addr_hash_lock);



static inline unsigned int inet_addr_hash(struct net *net, __be32 addr)

{

	u32 val = (__force u32) addr ^ hash_ptr(net, 8);



	return ((val ^ (val >> 8) ^ (val >> 16) ^ (val >> 24)) &

		(IN4_ADDR_HSIZE - 1));

}



static void inet_hash_insert(struct net *net, struct in_ifaddr *ifa)

{

	unsigned int hash = inet_addr_hash(net, ifa->ifa_address);



	spin_lock(&inet_addr_hash_lock);

	hlist_add_head_rcu(&ifa->hash, &inet_addr_lst[hash]);

	spin_unlock(&inet_addr_hash_lock);

}



static void inet_hash_remove(struct in_ifaddr *ifa)

{

	spin_lock(&inet_addr_hash_lock);

	hlist_del_init_rcu(&ifa->hash);

	spin_unlock(&inet_addr_hash_lock);

}



static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);



static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
@@ -265,6 +298,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, 
			}



			if (!do_promote) {

				inet_hash_remove(ifa);

				*ifap1 = ifa->ifa_next;



				rtmsg_ifa(RTM_DELADDR, ifa, nlh, pid);
@@ -281,6 +315,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, 
	/* 2. Unlink it */



	*ifap = ifa1->ifa_next;

	inet_hash_remove(ifa1);



	/* 3. Announce address deletion */
@@ -368,6 +403,8 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh, 
	ifa->ifa_next = *ifap;

	*ifap = ifa;



	inet_hash_insert(dev_net(in_dev->dev), ifa);



	/* Send message first, then call notifier.

	   Notifier will trigger FIB update, so that

	   listeners of netlink will know about new ifaddr */
@@ -521,6 +558,7 @@ static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh) 
	if (tb[IFA_ADDRESS] == NULL)

		tb[IFA_ADDRESS] = tb[IFA_LOCAL];



	INIT_HLIST_NODE(&ifa->hash);

	ifa->ifa_prefixlen = ifm->ifa_prefixlen;

	ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);

	ifa->ifa_flags = ifm->ifa_flags;
@@ -728,6 +766,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg) 
		if (!ifa) {

			ret = -ENOBUFS;

			ifa = inet_alloc_ifa();

			INIT_HLIST_NODE(&ifa->hash);

			if (!ifa)

				break;

			if (colon)
@@ -1069,6 +1108,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, 
			struct in_ifaddr *ifa = inet_alloc_ifa();



			if (ifa) {

				INIT_HLIST_NODE(&ifa->hash);

				ifa->ifa_local =

				  ifa->ifa_address = htonl(INADDR_LOOPBACK);

				ifa->ifa_prefixlen = 8;
@@ -1710,6 +1750,11 @@ static struct rtnl_af_ops inet_af_ops = { 


void __init devinet_init(void)

{

	int i;



	for (i = 0; i < IN4_ADDR_HSIZE; i++)

		INIT_HLIST_HEAD(&inet_addr_lst[i]);



	register_pernet_subsys(&devinet_ops);



	register_gifconf(PF_INET, inet_gifconf);