Commit b7b1bfce authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller
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ipv6: split duplicate address detection and router solicitation timer 



This patch splits the timers for duplicate address detection and router
solicitations apart. The router solicitations timer goes into inet6_dev
and the dad timer stays in inet6_ifaddr.

The reason behind this patch is to reduce the number of unneeded router
solicitations send out by the host if additional link-local addresses
are created. Currently we send out RS for every link-local address on
an interface.

If the RS timer fires we pick a source address with ipv6_get_lladdr. This
change could hurt people adding additional link-local addresses and
specifying these addresses in the radvd clients section because we
no longer guarantee that we use every ll address as source address in
router solicitations.

Cc: Flavio Leitner <fleitner@redhat.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Reviewed-by: default avatarFlavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 51151a16

include/net/if_inet6.h

+6 −2
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ struct inet6_ifaddr { 


	int			state;



	__u8			probes;

	__u8			dad_probes;

	__u8			flags;



	__u16			scope;
@@ -58,7 +58,7 @@ struct inet6_ifaddr { 
	unsigned long		cstamp;	/* created timestamp */

	unsigned long		tstamp; /* updated timestamp */



	struct timer_list	timer;

	struct timer_list	dad_timer;



	struct inet6_dev	*idev;

	struct rt6_info		*rt;
@@ -195,6 +195,10 @@ struct inet6_dev { 
	struct neigh_parms	*nd_parms;

	struct ipv6_devconf	cnf;

	struct ipv6_devstat	stats;



	struct timer_list	rs_timer;

	__u8			rs_probes;



	unsigned long		tstamp; /* ipv6InterfaceTable update timestamp */

	struct rcu_head		rcu;

};

net/ipv6/addrconf.c

+91 −73
Original line number Diff line number Diff line
@@ -253,37 +253,32 @@ static inline bool addrconf_qdisc_ok(const struct net_device *dev) 
	return !qdisc_tx_is_noop(dev);

}



static void addrconf_del_timer(struct inet6_ifaddr *ifp)

static void addrconf_del_rs_timer(struct inet6_dev *idev)

{

	if (del_timer(&ifp->timer))

	if (del_timer(&idev->rs_timer))

		__in6_dev_put(idev);

}



static void addrconf_del_dad_timer(struct inet6_ifaddr *ifp)

{

	if (del_timer(&ifp->dad_timer))

		__in6_ifa_put(ifp);

}



enum addrconf_timer_t {

	AC_NONE,

	AC_DAD,

	AC_RS,

};

static void addrconf_mod_rs_timer(struct inet6_dev *idev,

				  unsigned long when)

{

	if (!timer_pending(&idev->rs_timer))

		in6_dev_hold(idev);

	mod_timer(&idev->rs_timer, jiffies + when);

}



static void addrconf_mod_timer(struct inet6_ifaddr *ifp,

			       enum addrconf_timer_t what,

static void addrconf_mod_dad_timer(struct inet6_ifaddr *ifp,

				   unsigned long when)

{

	if (!del_timer(&ifp->timer))

	if (!timer_pending(&ifp->dad_timer))

		in6_ifa_hold(ifp);



	switch (what) {

	case AC_DAD:

		ifp->timer.function = addrconf_dad_timer;

		break;

	case AC_RS:

		ifp->timer.function = addrconf_rs_timer;

		break;

	default:

		break;

	}

	ifp->timer.expires = jiffies + when;

	add_timer(&ifp->timer);

	mod_timer(&ifp->dad_timer, jiffies + when);

}



static int snmp6_alloc_dev(struct inet6_dev *idev)
@@ -326,6 +321,7 @@ void in6_dev_finish_destroy(struct inet6_dev *idev) 


	WARN_ON(!list_empty(&idev->addr_list));

	WARN_ON(idev->mc_list != NULL);

	WARN_ON(timer_pending(&idev->rs_timer));



#ifdef NET_REFCNT_DEBUG

	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
@@ -357,7 +353,8 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) 
	rwlock_init(&ndev->lock);

	ndev->dev = dev;

	INIT_LIST_HEAD(&ndev->addr_list);



	setup_timer(&ndev->rs_timer, addrconf_rs_timer,

		    (unsigned long)ndev);

	memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf));

	ndev->cnf.mtu6 = dev->mtu;

	ndev->cnf.sysctl = NULL;
@@ -776,7 +773,7 @@ void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp) 


	in6_dev_put(ifp->idev);



	if (del_timer(&ifp->timer))

	if (del_timer(&ifp->dad_timer))

		pr_notice("Timer is still running, when freeing ifa=%p\n", ifp);



	if (ifp->state != INET6_IFADDR_STATE_DEAD) {
@@ -869,9 +866,9 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen, 


	spin_lock_init(&ifa->lock);

	spin_lock_init(&ifa->state_lock);

	init_timer(&ifa->timer);

	setup_timer(&ifa->dad_timer, addrconf_dad_timer,

		    (unsigned long)ifa);

	INIT_HLIST_NODE(&ifa->addr_lst);

	ifa->timer.data = (unsigned long) ifa;

	ifa->scope = scope;

	ifa->prefix_len = pfxlen;

	ifa->flags = flags | IFA_F_TENTATIVE;
@@ -994,7 +991,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) 
	}

	write_unlock_bh(&idev->lock);



	addrconf_del_timer(ifp);

	addrconf_del_dad_timer(ifp);



	ipv6_ifa_notify(RTM_DELADDR, ifp);
@@ -1447,18 +1444,12 @@ try_nextdev: 
}

EXPORT_SYMBOL(ipv6_dev_get_saddr);



int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,

static int __ipv6_get_lladdr(struct inet6_dev *idev, struct in6_addr *addr,

			     unsigned char banned_flags)

{

	struct inet6_dev *idev;

	int err = -EADDRNOTAVAIL;



	rcu_read_lock();

	idev = __in6_dev_get(dev);

	if (idev) {

	struct inet6_ifaddr *ifp;

	int err = -EADDRNOTAVAIL;



		read_lock_bh(&idev->lock);

	list_for_each_entry(ifp, &idev->addr_list, if_list) {

		if (ifp->scope == IFA_LINK &&

		    !(ifp->flags & banned_flags)) {
@@ -1467,6 +1458,20 @@ int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr, 
			break;

		}

	}

	return err;

}



int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,

		    unsigned char banned_flags)

{

	struct inet6_dev *idev;

	int err = -EADDRNOTAVAIL;



	rcu_read_lock();

	idev = __in6_dev_get(dev);

	if (idev) {

		read_lock_bh(&idev->lock);

		err = __ipv6_get_lladdr(idev, addr, banned_flags);

		read_unlock_bh(&idev->lock);

	}

	rcu_read_unlock();
@@ -1580,7 +1585,7 @@ static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed) 
{

	if (ifp->flags&IFA_F_PERMANENT) {

		spin_lock_bh(&ifp->lock);

		addrconf_del_timer(ifp);

		addrconf_del_dad_timer(ifp);

		ifp->flags |= IFA_F_TENTATIVE;

		if (dad_failed)

			ifp->flags |= IFA_F_DADFAILED;
@@ -3036,7 +3041,7 @@ static int addrconf_ifdown(struct net_device *dev, int how) 
		hlist_for_each_entry_rcu(ifa, h, addr_lst) {

			if (ifa->idev == idev) {

				hlist_del_init_rcu(&ifa->addr_lst);

				addrconf_del_timer(ifa);

				addrconf_del_dad_timer(ifa);

				goto restart;

			}

		}
@@ -3045,6 +3050,8 @@ static int addrconf_ifdown(struct net_device *dev, int how) 


	write_lock_bh(&idev->lock);



	addrconf_del_rs_timer(idev);



	/* Step 2: clear flags for stateless addrconf */

	if (!how)

		idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY);
@@ -3074,7 +3081,7 @@ static int addrconf_ifdown(struct net_device *dev, int how) 
	while (!list_empty(&idev->addr_list)) {

		ifa = list_first_entry(&idev->addr_list,

				       struct inet6_ifaddr, if_list);

		addrconf_del_timer(ifa);

		addrconf_del_dad_timer(ifa);



		list_del(&ifa->if_list);
@@ -3116,10 +3123,10 @@ static int addrconf_ifdown(struct net_device *dev, int how) 


static void addrconf_rs_timer(unsigned long data)

{

	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data;

	struct inet6_dev *idev = ifp->idev;

	struct inet6_dev *idev = (struct inet6_dev *)data;

	struct in6_addr lladdr;



	read_lock(&idev->lock);

	write_lock(&idev->lock);

	if (idev->dead || !(idev->if_flags & IF_READY))

		goto out;
@@ -3130,18 +3137,19 @@ static void addrconf_rs_timer(unsigned long data) 
	if (idev->if_flags & IF_RA_RCVD)

		goto out;



	spin_lock(&ifp->lock);

	if (ifp->probes++ < idev->cnf.rtr_solicits) {

	if (idev->rs_probes++ < idev->cnf.rtr_solicits) {

		if (!__ipv6_get_lladdr(idev, &lladdr, IFA_F_TENTATIVE))

			ndisc_send_rs(idev->dev, &lladdr,

				      &in6addr_linklocal_allrouters);

		else

			goto out;



		/* The wait after the last probe can be shorter */

		addrconf_mod_timer(ifp, AC_RS,

				   (ifp->probes == idev->cnf.rtr_solicits) ?

		addrconf_mod_rs_timer(idev, (idev->rs_probes ==

					     idev->cnf.rtr_solicits) ?

				      idev->cnf.rtr_solicit_delay :

				      idev->cnf.rtr_solicit_interval);

		spin_unlock(&ifp->lock);



		ndisc_send_rs(idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);

	} else {

		spin_unlock(&ifp->lock);

		/*

		 * Note: we do not support deprecated "all on-link"

		 * assumption any longer.
@@ -3150,8 +3158,8 @@ static void addrconf_rs_timer(unsigned long data) 
	}



out:

	read_unlock(&idev->lock);

	in6_ifa_put(ifp);

	write_unlock(&idev->lock);

	in6_dev_put(idev);

}



/*
@@ -3167,8 +3175,8 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp) 
	else

		rand_num = net_random() % (idev->cnf.rtr_solicit_delay ? : 1);



	ifp->probes = idev->cnf.dad_transmits;

	addrconf_mod_timer(ifp, AC_DAD, rand_num);

	ifp->dad_probes = idev->cnf.dad_transmits;

	addrconf_mod_dad_timer(ifp, rand_num);

}



static void addrconf_dad_start(struct inet6_ifaddr *ifp)
@@ -3229,40 +3237,40 @@ static void addrconf_dad_timer(unsigned long data) 
	struct inet6_dev *idev = ifp->idev;

	struct in6_addr mcaddr;



	if (!ifp->probes && addrconf_dad_end(ifp))

	if (!ifp->dad_probes && addrconf_dad_end(ifp))

		goto out;



	read_lock(&idev->lock);

	write_lock(&idev->lock);

	if (idev->dead || !(idev->if_flags & IF_READY)) {

		read_unlock(&idev->lock);

		write_unlock(&idev->lock);

		goto out;

	}



	spin_lock(&ifp->lock);

	if (ifp->state == INET6_IFADDR_STATE_DEAD) {

		spin_unlock(&ifp->lock);

		read_unlock(&idev->lock);

		write_unlock(&idev->lock);

		goto out;

	}



	if (ifp->probes == 0) {

	if (ifp->dad_probes == 0) {

		/*

		 * DAD was successful

		 */



		ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);

		spin_unlock(&ifp->lock);

		read_unlock(&idev->lock);

		write_unlock(&idev->lock);



		addrconf_dad_completed(ifp);



		goto out;

	}



	ifp->probes--;

	addrconf_mod_timer(ifp, AC_DAD, ifp->idev->nd_parms->retrans_time);

	ifp->dad_probes--;

	addrconf_mod_dad_timer(ifp, ifp->idev->nd_parms->retrans_time);

	spin_unlock(&ifp->lock);

	read_unlock(&idev->lock);

	write_unlock(&idev->lock);



	/* send a neighbour solicitation for our addr */

	addrconf_addr_solict_mult(&ifp->addr, &mcaddr);
@@ -3274,6 +3282,9 @@ out: 
static void addrconf_dad_completed(struct inet6_ifaddr *ifp)

{

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

	struct in6_addr lladdr;



	addrconf_del_dad_timer(ifp);



	/*

	 *	Configure the address for reception. Now it is valid.
@@ -3294,13 +3305,20 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) 
		 *	[...] as part of DAD [...] there is no need

		 *	to delay again before sending the first RS

		 */

		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);

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

			ndisc_send_rs(dev, &lladdr,

				      &in6addr_linklocal_allrouters);

		else

			return;



		spin_lock_bh(&ifp->lock);

		ifp->probes = 1;

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

		spin_lock(&ifp->lock);

		ifp->idev->rs_probes = 1;

		ifp->idev->if_flags |= IF_RS_SENT;

		addrconf_mod_timer(ifp, AC_RS, ifp->idev->cnf.rtr_solicit_interval);

		spin_unlock_bh(&ifp->lock);

		addrconf_mod_rs_timer(ifp->idev,

				      ifp->idev->cnf.rtr_solicit_interval);

		spin_unlock(&ifp->lock);

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

	}

}

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