mld: do not remove mld souce list info when set link down

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>

1 files changed, 30 insertions, 21 deletions

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 14a3903f1c82..7139fffd61b6 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -81,7 +81,7 @@ static void mld_gq_timer_expire(unsigned long data);
 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);
@@ -692,9 +692,9 @@ static void igmp6_group_dropped(struct ifmcaddr6 *mc)
                         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);
@@ -702,8 +702,6 @@ static void igmp6_group_dropped(struct ifmcaddr6 *mc)
         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);
 }
 
@@ -748,10 +746,11 @@ static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
         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;
@@ -768,14 +767,20 @@ static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *pmca)
         }
         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)
@@ -904,7 +909,7 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
         mca_get(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;
@@ -927,6 +932,7 @@ int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
                                 write_unlock_bh(&idev->lock);
 
                                 igmp6_group_dropped(ma);
+                                ip6_mc_clear_src(ma);
 
                                 ma_put(ma);
                                 return 0;
@@ -2501,15 +2507,17 @@ 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);
 }
 
 static void ipv6_mc_reset(struct inet6_dev *idev)
@@ -2531,8 +2539,10 @@ void ipv6_mc_up(struct inet6_dev *idev)
 
         read_lock_bh(&idev->lock);
         ipv6_mc_reset(idev);
-        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);
 }
 
@@ -2565,6 +2575,7 @@ void ipv6_mc_destroy_dev(struct inet6_dev *idev)
 
         /* 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
@@ -2579,11 +2590,9 @@ void ipv6_mc_destroy_dev(struct inet6_dev *idev)
         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);