[PATCH v3 1/1] igmp: call ip_mc_clear_src() only when we have no users of ip_mc_list
From: Veaceslav Falico <hidden>
Date: 2011-05-17 14:39:07
Also in:
linux-kbuild, lkml
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
In igmp_group_dropped() we call ip_mc_clear_src(), which resets the number of source filters per mulitcast. However, igmp_group_dropped() is also called on NETDEV_DOWN, NETDEV_PRE_TYPE_CHANGE and NETDEV_UNREGISTER, which means that the group might get added back on NETDEV_UP, NETDEV_REGISTER and NETDEV_POST_TYPE_CHANGE respectively, leaving us with broken source filters. To fix that, we must clear the source filters only when there are no users in the ip_mc_list, i.e. in ip_mc_dec_group(). Correct version of the patch. Signed-off-by: Veaceslav Falico <redacted> ---
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 1fd3d9c..142ca0d 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c@@ -1169,20 +1169,18 @@ static void igmp_group_dropped(struct ip_mc_list *im) if (!in_dev->dead) { if (IGMP_V1_SEEN(in_dev)) - goto done; + return; if (IGMP_V2_SEEN(in_dev)) { if (reporter) igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE); - goto done; + return; } /* IGMPv3 */ igmpv3_add_delrec(in_dev, im); igmp_ifc_event(in_dev); } -done: #endif - ip_mc_clear_src(im); } static void igmp_group_added(struct ip_mc_list *im)
@@ -1319,6 +1317,7 @@ void ip_mc_dec_group(struct in_device *in_dev, __be32 addr) *ip = i->next_rcu; in_dev->mc_count--; igmp_group_dropped(i); + ip_mc_clear_src(i); if (!in_dev->dead) ip_rt_multicast_event(in_dev);