From: Veaceslav Falico Date: Mon, 23 May 2011 23:15:05 +0000 (+0000) Subject: igmp: call ip_mc_clear_src() only when we have no users of ip_mc_list X-Git-Url: http://git.alex.org.uk igmp: call ip_mc_clear_src() only when we have no users of ip_mc_list BugLink: http://bugs.launchpad.net/bugs/793702 [ Upstream commit 24cf3af3fed5edcf90bc2a0ed181e6ce1513d2dc ] 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() and on device destroy. Acked-by: David L Stevens Signed-off-by: Veaceslav Falico Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Tim Gardner --- diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index e0e77e2..d9d5130 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -1172,20 +1172,18 @@ 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) @@ -1322,6 +1320,7 @@ 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); @@ -1431,7 +1430,8 @@ void ip_mc_destroy_dev(struct in_device *in_dev) in_dev->mc_list = i->next_rcu; in_dev->mc_count--; - igmp_group_dropped(i); + /* We've dropped the groups in ip_mc_down already */ + ip_mc_clear_src(i); ip_ma_put(i); } }