Commit 1ec047eb authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller
Browse files

ipv6: introduce per-interface counter for dad-completed ipv6 addresses 



To reduce the number of unnecessary router solicitations, MLDv2 and IGMPv3
messages we need to track the number of valid (as in non-optimistic,
no-dad-failed and non-tentative) link-local addresses. Therefore, this
patch implements a valid_ll_addr_cnt in struct inet6_dev.

We now only emit router solicitations if the first link-local address
finishes duplicate address detection.

The changes for MLDv2 and IGMPv3 are in a follow-up patch.

While there, also simplify one if statement(one minor nit I made in one
of my previous patches):

if (!...)
	do();
else
	return;

<<into>>

if (...)
	return;
do();

Cc: Flavio Leitner <fbl@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: David Stevens <dlstevens@us.ibm.com>
Suggested-by: default avatarDavid Stevens <dlstevens@us.ibm.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: default avatarFlavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ae0d6750

include/net/if_inet6.h

+1 −0
Original line number Diff line number Diff line
@@ -166,6 +166,7 @@ struct inet6_dev { 
	struct net_device	*dev;



	struct list_head	addr_list;

	int			valid_ll_addr_cnt;



	struct ifmcaddr6	*mc_list;

	struct ifmcaddr6	*mc_tomb;

net/ipv6/addrconf.c

+31 −8
Original line number Diff line number Diff line
@@ -3277,6 +3277,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) 
{

	struct net_device *dev = ifp->idev->dev;

	struct in6_addr lladdr;

	bool send_rs;



	addrconf_del_dad_timer(ifp);
@@ -3290,20 +3291,25 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) 
	   router advertisements, start sending router solicitations.

	 */



	if (ipv6_accept_ra(ifp->idev) &&

	read_lock_bh(&ifp->idev->lock);

	spin_lock(&ifp->lock);

	send_rs = ipv6_accept_ra(ifp->idev) &&

		  ifp->idev->cnf.rtr_solicits > 0 &&

		  (dev->flags&IFF_LOOPBACK) == 0 &&

	    (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) {

		  ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL &&

		  ifp->idev->valid_ll_addr_cnt == 1;

	spin_unlock(&ifp->lock);

	read_unlock_bh(&ifp->idev->lock);



	if (send_rs) {

		/*

		 *	If a host as already performed a random delay

		 *	[...] as part of DAD [...] there is no need

		 *	to delay again before sending the first RS

		 */

		if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))

			ndisc_send_rs(dev, &lladdr,

				      &in6addr_linklocal_allrouters);

		else

		if (ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))

			return;

		ndisc_send_rs(dev, &lladdr, &in6addr_linklocal_allrouters);



		write_lock_bh(&ifp->idev->lock);

		spin_lock(&ifp->lock);
@@ -4576,6 +4582,19 @@ errout: 
		rtnl_set_sk_err(net, RTNLGRP_IPV6_PREFIX, err);

}



static void update_valid_ll_addr_cnt(struct inet6_ifaddr *ifp, int count)

{

	write_lock_bh(&ifp->idev->lock);

	spin_lock(&ifp->lock);

	if (((ifp->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|

			    IFA_F_DADFAILED)) == IFA_F_PERMANENT) &&

	    (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL))

		ifp->idev->valid_ll_addr_cnt += count;

	WARN_ON(ifp->idev->valid_ll_addr_cnt < 0);

	spin_unlock(&ifp->lock);

	write_unlock_bh(&ifp->idev->lock);

}



static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)

{

	struct net *net = dev_net(ifp->idev->dev);
@@ -4584,6 +4603,8 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) 


	switch (event) {

	case RTM_NEWADDR:

		update_valid_ll_addr_cnt(ifp, 1);



		/*

		 * If the address was optimistic

		 * we inserted the route at the start of
@@ -4599,6 +4620,8 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) 
					      ifp->idev->dev, 0, 0);

		break;

	case RTM_DELADDR:

		update_valid_ll_addr_cnt(ifp, -1);



		if (ifp->idev->cnf.forwarding)

			addrconf_leave_anycast(ifp);

		addrconf_leave_solict(ifp->idev, &ifp->addr);

CRA Git | Maintained and supported by SUSTech CRA and CCSE