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Commit c7ea20c9 authored by Hangbin Liu's avatar Hangbin Liu Committed by David S. Miller
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ipv6/mcast: init as INCLUDE when join SSM INCLUDE group 



This an IPv6 version patch of "ipv4/igmp: init group mode as INCLUDE when
join source group". From RFC3810, part 6.1:

   If no per-interface state existed for that
   multicast address before the change (i.e., the change consisted of
   creating a new per-interface record), or if no state exists after the
   change (i.e., the change consisted of deleting a per-interface
   record), then the "non-existent" state is considered to have an
   INCLUDE filter mode and an empty source list.

Which means a new multicast group should start with state IN(). Currently,
for MLDv2 SSM JOIN_SOURCE_GROUP mode, we first call ipv6_sock_mc_join(),
then ip6_mc_source(), which will trigger a TO_IN() message instead of
ALLOW().

The issue was exposed by commit a052517a ("net/multicast: should not
send source list records when have filter mode change"). Before this change,
we sent both ALLOW(A) and TO_IN(A). Now, we only send TO_IN(A).

Fix it by adding a new parameter to init group mode. Also add some wrapper
functions to avoid changing too much code.

v1 -> v2:
In the first version I only cleared the group change record. But this is not
enough. Because when a new group join, it will init as EXCLUDE and trigger
a filter mode change in ip/ip6_mc_add_src(), which will clear all source
addresses sf_crcount. This will prevent early joined address sending state
change records if multi source addressed joined at the same time.

In v2 patch, I fixed it by directly initializing the mode to INCLUDE for SSM
JOIN_SOURCE_GROUP. I also split the original patch into two separated patches
for IPv4 and IPv6.

There is also a difference between v4 and v6 version. For IPv6, when the
interface goes down and up, we will send correct state change record with
unspecified IPv6 address (::) with function ipv6_mc_up(). But after DAD is
completed, we resend the change record TO_IN() in mld_send_initial_cr().
Fix it by sending ALLOW() for INCLUDE mode in mld_send_initial_cr().

Fixes: a052517a ("net/multicast: should not send source list records when have filter mode change")
Reviewed-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarHangbin Liu <liuhangbin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6e2059b5

include/net/ipv6.h

+2 −0
Original line number Diff line number Diff line
@@ -1100,6 +1100,8 @@ void ipv6_sysctl_unregister(void); 


int ipv6_sock_mc_join(struct sock *sk, int ifindex,

		      const struct in6_addr *addr);

int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,

			  const struct in6_addr *addr, unsigned int mode);

int ipv6_sock_mc_drop(struct sock *sk, int ifindex,

		      const struct in6_addr *addr);

#endif /* _NET_IPV6_H */

net/ipv6/ipv6_sockglue.c

+3 −2
Original line number Diff line number Diff line
@@ -729,8 +729,9 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, 
			struct sockaddr_in6 *psin6;



			psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;

			retv = ipv6_sock_mc_join(sk, greqs.gsr_interface,

						 &psin6->sin6_addr);

			retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,

						     &psin6->sin6_addr,

						     MCAST_INCLUDE);

			/* prior join w/ different source is ok */

			if (retv && retv != -EADDRINUSE)

				break;

net/ipv6/mcast.c

+45 −19
Original line number Diff line number Diff line
@@ -95,6 +95,8 @@ static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca, 
			  int delta);

static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,

			    struct inet6_dev *idev);

static int __ipv6_dev_mc_inc(struct net_device *dev,

			     const struct in6_addr *addr, unsigned int mode);



#define MLD_QRV_DEFAULT		2

/* RFC3810, 9.2. Query Interval */
@@ -132,7 +134,8 @@ static int unsolicited_report_interval(struct inet6_dev *idev) 
	return iv > 0 ? iv : 1;

}



int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)

static int __ipv6_sock_mc_join(struct sock *sk, int ifindex,

			       const struct in6_addr *addr, unsigned int mode)

{

	struct net_device *dev = NULL;

	struct ipv6_mc_socklist *mc_lst;
@@ -179,7 +182,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
	}



	mc_lst->ifindex = dev->ifindex;

	mc_lst->sfmode = MCAST_EXCLUDE;

	mc_lst->sfmode = mode;

	rwlock_init(&mc_lst->sflock);

	mc_lst->sflist = NULL;
@@ -187,7 +190,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
	 *	now add/increase the group membership on the device

	 */



	err = ipv6_dev_mc_inc(dev, addr);

	err = __ipv6_dev_mc_inc(dev, addr, mode);



	if (err) {

		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
@@ -199,8 +202,19 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 


	return 0;

}



int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)

{

	return __ipv6_sock_mc_join(sk, ifindex, addr, MCAST_EXCLUDE);

}

EXPORT_SYMBOL(ipv6_sock_mc_join);



int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,

			  const struct in6_addr *addr, unsigned int mode)

{

	return __ipv6_sock_mc_join(sk, ifindex, addr, mode);

}



/*

 *	socket leave on multicast group

 */
@@ -646,7 +660,7 @@ bool inet6_mc_check(struct sock *sk, const struct in6_addr *mc_addr, 
	return rv;

}



static void igmp6_group_added(struct ifmcaddr6 *mc)

static void igmp6_group_added(struct ifmcaddr6 *mc, unsigned int mode)

{

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

	char buf[MAX_ADDR_LEN];
@@ -672,7 +686,13 @@ static void igmp6_group_added(struct ifmcaddr6 *mc) 
	}

	/* else v2 */



	/* Based on RFC3810 6.1, for newly added INCLUDE SSM, we

	 * should not send filter-mode change record as the mode

	 * should be from IN() to IN(A).

	 */

	if (mode == MCAST_EXCLUDE)

		mc->mca_crcount = mc->idev->mc_qrv;



	mld_ifc_event(mc->idev);

}
@@ -770,13 +790,14 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im) 
	spin_lock_bh(&im->mca_lock);

	if (pmc) {

		im->idev = pmc->idev;

		im->mca_crcount = idev->mc_qrv;

		im->mca_sfmode = pmc->mca_sfmode;

		if (pmc->mca_sfmode == MCAST_INCLUDE) {

			im->mca_tomb = pmc->mca_tomb;

			im->mca_sources = pmc->mca_sources;

			for (psf = im->mca_sources; psf; psf = psf->sf_next)

				psf->sf_crcount = im->mca_crcount;

				psf->sf_crcount = idev->mc_qrv;

		} else {

			im->mca_crcount = idev->mc_qrv;

		}

		in6_dev_put(pmc->idev);

		kfree(pmc);
@@ -831,7 +852,8 @@ static void ma_put(struct ifmcaddr6 *mc) 
}



static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,

				   const struct in6_addr *addr)

				   const struct in6_addr *addr,

				   unsigned int mode)

{

	struct ifmcaddr6 *mc;
@@ -849,9 +871,8 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev, 
	refcount_set(&mc->mca_refcnt, 1);

	spin_lock_init(&mc->mca_lock);



	/* initial mode is (EX, empty) */

	mc->mca_sfmode = MCAST_EXCLUDE;

	mc->mca_sfcount[MCAST_EXCLUDE] = 1;

	mc->mca_sfmode = mode;

	mc->mca_sfcount[mode] = 1;



	if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||

	    IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
@@ -863,7 +884,8 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev, 
/*

 *	device multicast group inc (add if not found)

 */

int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)

static int __ipv6_dev_mc_inc(struct net_device *dev,

			     const struct in6_addr *addr, unsigned int mode)

{

	struct ifmcaddr6 *mc;

	struct inet6_dev *idev;
@@ -887,14 +909,13 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr) 
		if (ipv6_addr_equal(&mc->mca_addr, addr)) {

			mc->mca_users++;

			write_unlock_bh(&idev->lock);

			ip6_mc_add_src(idev, &mc->mca_addr, MCAST_EXCLUDE, 0,

				NULL, 0);

			ip6_mc_add_src(idev, &mc->mca_addr, mode, 0, NULL, 0);

			in6_dev_put(idev);

			return 0;

		}

	}



	mc = mca_alloc(idev, addr);

	mc = mca_alloc(idev, addr, mode);

	if (!mc) {

		write_unlock_bh(&idev->lock);

		in6_dev_put(idev);
@@ -911,11 +932,16 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr) 
	write_unlock_bh(&idev->lock);



	mld_del_delrec(idev, mc);

	igmp6_group_added(mc);

	igmp6_group_added(mc, mode);

	ma_put(mc);

	return 0;

}



int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)

{

	return __ipv6_dev_mc_inc(dev, addr, MCAST_EXCLUDE);

}



/*

 *	device multicast group del

 */
@@ -1751,7 +1777,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc, 


		psf_next = psf->sf_next;



		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {

		if (!is_in(pmc, psf, type, gdeleted, sdeleted) && !crsend) {

			psf_prev = psf;

			continue;

		}
@@ -2066,7 +2092,7 @@ static void mld_send_initial_cr(struct inet6_dev *idev) 
		if (pmc->mca_sfcount[MCAST_EXCLUDE])

			type = MLD2_CHANGE_TO_EXCLUDE;

		else

			type = MLD2_CHANGE_TO_INCLUDE;

			type = MLD2_ALLOW_NEW_SOURCES;

		skb = add_grec(skb, pmc, type, 0, 0, 1);

		spin_unlock_bh(&pmc->mca_lock);

	}
@@ -2546,7 +2572,7 @@ void ipv6_mc_up(struct inet6_dev *idev) 
	ipv6_mc_reset(idev);

	for (i = idev->mc_list; i; i = i->next) {

		mld_del_delrec(idev, i);

		igmp6_group_added(i);

		igmp6_group_added(i, i->mca_sfmode);

	}

	read_unlock_bh(&idev->lock);

}