[PATCH 3.2 086/126] igmp: do not remove igmp souce list info when set link down

Ben Hutchings
2017-02-15T22:53:43Z

From: Hangbin Liu <liuhangbin@gmail.com>

commit 24803f38a5c0b6c57ed800b47e695f9ce474bc3a upstream.

In commit 24cf3af3fed5 ("igmp: call ip_mc_clear_src..."), we forgot to remove
igmpv3_clear_delrec() in ip_mc_down(), which also called ip_mc_clear_src().
This make us clear all IGMPv3 source filter info after NETDEV_DOWN.
Move igmpv3_clear_delrec() to ip_mc_destroy_dev() and then no need
ip_mc_clear_src() in ip_mc_destroy_dev().

On the other hand, we should restore back instead of free all source filter
info in igmpv3_del_delrec(). Or we will not able to restore IGMPv3 source
filter info after NETDEV_UP and NETDEV_POST_TYPE_CHANGE.

Fixes: 24cf3af3fed5 ("igmp: call ip_mc_clear_src() only when ...")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
- Use IGMP_Unsolicited_Report_Count instead of sysctl_igmp_qrv
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -140,7 +140,7 @@
time_before(jiffies, (in_dev)->mr_v2_seen)))

static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
-static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
+static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
static void igmpv3_clear_delrec(struct in_device *in_dev);
static int sf_setstate(struct ip_mc_list *pmc);
static void sf_markstate(struct ip_mc_list *pmc);
@@ -1077,10 +1077,14 @@ static void igmpv3_add_delrec(struct in_
spin_unlock_bh(&in_dev->mc_tomb_lock);
}

-static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
+/*
+ * restore ip_mc_list deleted records
+ */
+static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
{
struct ip_mc_list *pmc, *pmc_prev;
- struct ip_sf_list *psf, *psf_next;
+ struct ip_sf_list *psf;
+ __be32 multiaddr = im->multiaddr;

spin_lock_bh(&in_dev->mc_tomb_lock);
pmc_prev = NULL;
@@ -1096,16 +1100,26 @@ static void igmpv3_del_delrec(struct in_
in_dev->mc_tomb = pmc->next;
}
spin_unlock_bh(&in_dev->mc_tomb_lock);
+
+ spin_lock_bh(&im->lock);
if (pmc) {
- for (psf=pmc->tomb; psf; psf=psf_next) {
- psf_next = psf->sf_next;
- kfree(psf);
+ im->interface = pmc->interface;
+ im->crcount = in_dev->mr_qrv ?: IGMP_Unsolicited_Report_Count;
+ im->sfmode = pmc->sfmode;
+ if (pmc->sfmode == MCAST_INCLUDE) {
+ im->tomb = pmc->tomb;
+ im->sources = pmc->sources;
+ for (psf = im->sources; psf; psf = psf->sf_next)
+ psf->sf_crcount = im->crcount;
}
in_dev_put(pmc->interface);
- kfree(pmc);
}
+ spin_unlock_bh(&im->lock);
}

+/*
+ * flush ip_mc_list deleted records
+ */
static void igmpv3_clear_delrec(struct in_device *in_dev)
{
struct ip_mc_list *pmc, *nextpmc;
@@ -1250,7 +1264,7 @@ void ip_mc_inc_group(struct in_device *i
rcu_assign_pointer(in_dev->mc_list, im);

#ifdef CONFIG_IP_MULTICAST
- igmpv3_del_delrec(in_dev, im->multiaddr);
+ igmpv3_del_delrec(in_dev, im);
#endif
igmp_group_added(im);
if (!in_dev->dead)
@@ -1340,8 +1354,12 @@ void ip_mc_remap(struct in_device *in_de

ASSERT_RTNL();

- for_each_pmc_rtnl(in_dev, pmc)
+ for_each_pmc_rtnl(in_dev, pmc) {
+#ifdef CONFIG_IP_MULTICAST
+ igmpv3_del_delrec(in_dev, pmc);
+#endif
igmp_group_added(pmc);
+ }
}

/* Device going down */
@@ -1362,7 +1380,6 @@ void ip_mc_down(struct in_device *in_dev
in_dev->mr_gq_running = 0;
if (del_timer(&in_dev->mr_gq_timer))
__in_dev_put(in_dev);
- igmpv3_clear_delrec(in_dev);
#endif

ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
@@ -1397,8 +1414,12 @@ void ip_mc_up(struct in_device *in_dev)

ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);

- for_each_pmc_rtnl(in_dev, pmc)
+ for_each_pmc_rtnl(in_dev, pmc) {
+#ifdef CONFIG_IP_MULTICAST
+ igmpv3_del_delrec(in_dev, pmc);
+#endif
igmp_group_added(pmc);
+ }
}

/*
@@ -1413,13 +1434,13 @@ void ip_mc_destroy_dev(struct in_device

/* Deactivate timers */
ip_mc_down(in_dev);
+#ifdef CONFIG_IP_MULTICAST
+ igmpv3_clear_delrec(in_dev);
+#endif

while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
in_dev->mc_list = i->next_rcu;
in_dev->mc_count--;
-
- /* We've dropped the groups in ip_mc_down already */
- ip_mc_clear_src(i);
ip_ma_put(i);
}
}