[PATCH 3.16 364/370] mld: do not remove mld souce list info when set link down

Ben Hutchings
2017-03-10T12:22:24Z

From: Hangbin Liu <liuhangbin@gmail.com>

commit 1666d49e1d416fcc2cce708242a52fe3317ea8ba upstream.

This is an IPv6 version of commit 24803f38a5c0 ("igmp: do not remove igmp
souce list..."). In mld_del_delrec(), we will restore back all source filter
info instead of flush them.

Move mld_clear_delrec() from ipv6_mc_down() to ipv6_mc_destroy_dev() since
we should not remove source list info when set link down. Remove
igmp6_group_dropped() in ipv6_mc_destroy_dev() since we have called it in
ipv6_mc_down().

Also clear all source info after igmp6_group_dropped() instead of in it
because ipv6_mc_down() will call igmp6_group_dropped().

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/ipv6/mcast.c | 51 ++++++++++++++++++++++++++++++---------------------
1 file changed, 30 insertions(+), 21 deletions(-)

--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -93,7 +93,7 @@ static void mld_gq_timer_expire(unsigned
static void mld_ifc_timer_expire(unsigned long data);
static void mld_ifc_event(struct inet6_dev *idev);
static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
-static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *addr);
+static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
static void mld_clear_delrec(struct inet6_dev *idev);
static bool mld_in_v1_mode(const struct inet6_dev *idev);
static int sf_setstate(struct ifmcaddr6 *pmc);
@@ -727,9 +727,9 @@ static void igmp6_group_dropped(struct i
dev_mc_del(dev, buf);
}

- if (mc->mca_flags & MAF_NOREPORT)
- goto done;
spin_unlock_bh(&mc->mca_lock);
+ if (mc->mca_flags & MAF_NOREPORT)
+ return;

if (!mc->idev->dead)
igmp6_leave_group(mc);
@@ -737,8 +737,6 @@ static void igmp6_group_dropped(struct i
spin_lock_bh(&mc->mca_lock);
if (del_timer(&mc->mca_timer))
atomic_dec(&mc->mca_refcnt);
-done:
- ip6_mc_clear_src(mc);
spin_unlock_bh(&mc->mca_lock);
}

@@ -783,10 +781,11 @@ static void mld_add_delrec(struct inet6_
spin_unlock_bh(&idev->mc_lock);
}

-static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *pmca)
+static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
{
struct ifmcaddr6 *pmc, *pmc_prev;
- struct ip6_sf_list *psf, *psf_next;
+ struct ip6_sf_list *psf;
+ struct in6_addr *pmca = &im->mca_addr;

spin_lock_bh(&idev->mc_lock);
pmc_prev = NULL;
@@ -803,14 +802,20 @@ static void mld_del_delrec(struct inet6_
}
spin_unlock_bh(&idev->mc_lock);

+ spin_lock_bh(&im->mca_lock);
if (pmc) {
- for (psf=pmc->mca_tomb; psf; psf=psf_next) {
- psf_next = psf->sf_next;
- kfree(psf);
+ 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;
}
in6_dev_put(pmc->idev);
- kfree(pmc);
}
+ spin_unlock_bh(&im->mca_lock);
}

static void mld_clear_delrec(struct inet6_dev *idev)
@@ -915,7 +920,7 @@ int ipv6_dev_mc_inc(struct net_device *d
idev->mc_list = mc;
write_unlock_bh(&idev->lock);

- mld_del_delrec(idev, &mc->mca_addr);
+ mld_del_delrec(idev, mc);
igmp6_group_added(mc);
ma_put(mc);
return 0;
@@ -938,6 +943,7 @@ int __ipv6_dev_mc_dec(struct inet6_dev *
write_unlock_bh(&idev->lock);

igmp6_group_dropped(ma);
+ ip6_mc_clear_src(ma);

ma_put(ma);
return 0;
@@ -2479,15 +2485,17 @@ void ipv6_mc_down(struct inet6_dev *idev
/* Withdraw multicast list */

read_lock_bh(&idev->lock);
- mld_ifc_stop_timer(idev);
- mld_gq_stop_timer(idev);
- mld_dad_stop_timer(idev);

for (i = idev->mc_list; i; i=i->next)
igmp6_group_dropped(i);
- read_unlock_bh(&idev->lock);

- mld_clear_delrec(idev);
+ /* Should stop timer after group drop. or we will
+ * start timer again in mld_ifc_event()
+ */
+ mld_ifc_stop_timer(idev);
+ mld_gq_stop_timer(idev);
+ mld_dad_stop_timer(idev);
+ read_unlock_bh(&idev->lock);
}

@@ -2500,8 +2508,10 @@ void ipv6_mc_up(struct inet6_dev *idev)
/* Install multicast list, except for all-nodes (already installed) */

read_lock_bh(&idev->lock);
- for (i = idev->mc_list; i; i=i->next)
+ for (i = idev->mc_list; i; i = i->next) {
+ mld_del_delrec(idev, i);
igmp6_group_added(i);
+ }
read_unlock_bh(&idev->lock);
}

@@ -2540,6 +2550,7 @@ void ipv6_mc_destroy_dev(struct inet6_de

/* Deactivate timers */
ipv6_mc_down(idev);
+ mld_clear_delrec(idev);

/* Delete all-nodes address. */
/* We cannot call ipv6_dev_mc_dec() directly, our caller in
@@ -2554,11 +2565,9 @@ void ipv6_mc_destroy_dev(struct inet6_de
write_lock_bh(&idev->lock);
while ((i = idev->mc_list) != NULL) {
idev->mc_list = i->next;
- write_unlock_bh(&idev->lock);

- igmp6_group_dropped(i);
+ write_unlock_bh(&idev->lock);
ma_put(i);
-
write_lock_bh(&idev->lock);
}
write_unlock_bh(&idev->lock);