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Commit 3a88a81d authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

ipv6: user better hash for addrconf 



The existing hash function has a couple of issues:
  * it is hardwired to 16 for IN6_ADDR_HSIZE
  * limited to 256 and callers using int
  * use jhash2 rather than some old BSD algorithm

No need for random seed since this is local only (based on assigned
addresses) table.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5c578aed

net/ipv6/addrconf.c

+8 −17
Original line number Diff line number Diff line
@@ -573,23 +573,14 @@ ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp) 
	*ifap = ifp;

}



/*

 *	Hash function taken from net_alias.c

 */

static u8 ipv6_addr_hash(const struct in6_addr *addr)

static u32 ipv6_addr_hash(const struct in6_addr *addr)

{

	__u32 word;



	/*

	 * We perform the hash function over the last 64 bits of the address

	 * This will include the IEEE address token on links that support it.

	 */



	word = (__force u32)(addr->s6_addr32[2] ^ addr->s6_addr32[3]);

	word ^= (word >> 16);

	word ^= (word >> 8);



	return ((word ^ (word >> 4)) & 0x0f);

	return jhash_2words(addr->s6_addr32[2],  addr->s6_addr32[3], 0)

		& (IN6_ADDR_HSIZE - 1);

}



/* On success it returns ifp with increased reference count */
@@ -600,7 +591,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen, 
{

	struct inet6_ifaddr *ifa = NULL;

	struct rt6_info *rt;

	int hash;

	unsigned int hash;

	int err = 0;

	int addr_type = ipv6_addr_type(addr);
@@ -1277,7 +1268,7 @@ int ipv6_chk_addr(struct net *net, struct in6_addr *addr, 
{

	struct inet6_ifaddr *ifp = NULL;

	struct hlist_node *node;

	u8 hash = ipv6_addr_hash(addr);

	unsigned int hash = ipv6_addr_hash(addr);



	rcu_read_lock_bh();

	hlist_for_each_entry_rcu(ifp, node, &inet6_addr_lst[hash], addr_lst) {
@@ -1302,7 +1293,7 @@ int ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr, 
{

	struct inet6_ifaddr *ifp;

	struct hlist_node *node;

	u8 hash = ipv6_addr_hash(addr);

	unsigned int hash = ipv6_addr_hash(addr);



	hlist_for_each_entry(ifp, node, &inet6_addr_lst[hash], addr_lst) {

		if (!net_eq(dev_net(ifp->idev->dev), net))
@@ -1345,7 +1336,7 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add 
{

	struct inet6_ifaddr *ifp = NULL;

	struct hlist_node *node;

	u8 hash = ipv6_addr_hash(addr);

	unsigned int hash = ipv6_addr_hash(addr);



	rcu_read_lock_bh();

	hlist_for_each_entry_rcu(ifp, node, &inet6_addr_lst[hash], addr_lst) {
@@ -3083,7 +3074,7 @@ int ipv6_chk_home_addr(struct net *net, struct in6_addr *addr) 
	int ret = 0;

	struct inet6_ifaddr *ifp = NULL;

	struct hlist_node *n;

	u8 hash = ipv6_addr_hash(addr);

	unsigned int hash = ipv6_addr_hash(addr);



	rcu_read_lock_bh();

	hlist_for_each_entry_rcu(ifp, n, &inet6_addr_lst[hash], addr_lst) {