path: root/net
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authorHangbin Liu <liuhangbin@gmail.com>2020-03-10 15:27:37 +0800
committerDavid S. Miller <davem@davemloft.net>2020-03-10 15:37:49 -0700
commit60380488e4e0b95e9e82aa68aa9705baa86de84c (patch)
treefa746cefcf861685554fa60b78db0afcac084747 /net
parentnet: memcg: late association of sock to memcg (diff)
ipv6/addrconf: call ipv6_mc_up() for non-Ethernet interface
Rafał found an issue that for non-Ethernet interface, if we down and up frequently, the memory will be consumed slowly. The reason is we add allnodes/allrouters addressed in multicast list in ipv6_add_dev(). When link down, we call ipv6_mc_down(), store all multicast addresses via mld_add_delrec(). But when link up, we don't call ipv6_mc_up() for non-Ethernet interface to remove the addresses. This makes idev->mc_tomb getting bigger and bigger. The call stack looks like: addrconf_notify(NETDEV_REGISTER) ipv6_add_dev ipv6_dev_mc_inc(ff01::1) ipv6_dev_mc_inc(ff02::1) ipv6_dev_mc_inc(ff02::2) addrconf_notify(NETDEV_UP) addrconf_dev_config /* Alas, we support only Ethernet autoconfiguration. */ return; addrconf_notify(NETDEV_DOWN) addrconf_ifdown ipv6_mc_down igmp6_group_dropped(ff02::2) mld_add_delrec(ff02::2) igmp6_group_dropped(ff02::1) igmp6_group_dropped(ff01::1) After investigating, I can't found a rule to disable multicast on non-Ethernet interface. In RFC2460, the link could be Ethernet, PPP, ATM, tunnels, etc. In IPv4, it doesn't check the dev type when calls ip_mc_up() in inetdev_event(). Even for IPv6, we don't check the dev type and call ipv6_add_dev(), ipv6_dev_mc_inc() after register device. So I think it's OK to fix this memory consumer by calling ipv6_mc_up() for non-Ethernet interface. v2: Also check IFF_MULTICAST flag to make sure the interface supports multicast Reported-by: Rafał Miłecki <zajec5@gmail.com> Tested-by: Rafał Miłecki <zajec5@gmail.com> Fixes: 74235a25c673 ("[IPV6] addrconf: Fix IPv6 on tuntap tunnels") Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when set link down") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index e6e1290ea06f..46d614b611db 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3347,6 +3347,10 @@ static void addrconf_dev_config(struct net_device *dev)
(dev->type != ARPHRD_NONE) &&
(dev->type != ARPHRD_RAWIP)) {
/* Alas, we support only Ethernet autoconfiguration. */
+ idev = __in6_dev_get(dev);
+ if (!IS_ERR_OR_NULL(idev) && dev->flags & IFF_UP &&
+ dev->flags & IFF_MULTICAST)
+ ipv6_mc_up(idev);