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authordaniel <daniel@dd-wrt.com>2016-06-24 12:35:18 +0200
committerDavid S. Miller <davem@davemloft.net>2016-06-28 08:03:04 -0400
commit0888d5f3c0f183ea6177355752ada433d370ac89 (patch)
treef1f08f5ef45de5caa8c8b7448ccec071540db60e /net
parentf299a02d5f13c4deb52c1a7ddf2b42630fe6294a (diff)
downloadlinux-0888d5f3c0f183ea6177355752ada433d370ac89.tar.gz
Bridge: Fix ipv6 mc snooping if bridge has no ipv6 address
The bridge is falsly dropping ipv6 mulitcast packets if there is: 1. No ipv6 address assigned on the brigde. 2. No external mld querier present. 3. The internal querier enabled. When the bridge fails to build mld queries, because it has no ipv6 address, it slilently returns, but keeps the local querier enabled. This specific case causes confusing packet loss. Ipv6 multicast snooping can only work if: a) An external querier is present OR b) The bridge has an ipv6 address an is capable of sending own queries Otherwise it has to forward/flood the ipv6 multicast traffic, because snooping cannot work. This patch fixes the issue by adding a flag to the bridge struct that indicates that there is currently no ipv6 address assinged to the bridge and returns a false state for the local querier in __br_multicast_querier_exists(). Special thanks to Linus Lüssing. Fixes: d1d81d4c3dd8 ("bridge: check return value of ipv6_dev_get_saddr()") Signed-off-by: Daniel Danzberger <daniel@dd-wrt.com> Acked-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/bridge/br_multicast.c4
-rw-r--r--net/bridge/br_private.h23
2 files changed, 23 insertions, 4 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 6852f3c7009c..43844144c9c4 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -464,8 +464,11 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
&ip6h->saddr)) {
kfree_skb(skb);
+ br->has_ipv6_addr = 0;
return NULL;
}
+
+ br->has_ipv6_addr = 1;
ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
hopopt = (u8 *)(ip6h + 1);
@@ -1745,6 +1748,7 @@ void br_multicast_init(struct net_bridge *br)
br->ip6_other_query.delay_time = 0;
br->ip6_querier.port = NULL;
#endif
+ br->has_ipv6_addr = 1;
spin_lock_init(&br->multicast_lock);
setup_timer(&br->multicast_router_timer,
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index c7fb5d7a7218..52edecf3c294 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -314,6 +314,7 @@ struct net_bridge
u8 multicast_disabled:1;
u8 multicast_querier:1;
u8 multicast_query_use_ifaddr:1;
+ u8 has_ipv6_addr:1;
u32 hash_elasticity;
u32 hash_max;
@@ -588,10 +589,22 @@ static inline bool br_multicast_is_router(struct net_bridge *br)
static inline bool
__br_multicast_querier_exists(struct net_bridge *br,
- struct bridge_mcast_other_query *querier)
+ struct bridge_mcast_other_query *querier,
+ const bool is_ipv6)
{
+ bool own_querier_enabled;
+
+ if (br->multicast_querier) {
+ if (is_ipv6 && !br->has_ipv6_addr)
+ own_querier_enabled = false;
+ else
+ own_querier_enabled = true;
+ } else {
+ own_querier_enabled = false;
+ }
+
return time_is_before_jiffies(querier->delay_time) &&
- (br->multicast_querier || timer_pending(&querier->timer));
+ (own_querier_enabled || timer_pending(&querier->timer));
}
static inline bool br_multicast_querier_exists(struct net_bridge *br,
@@ -599,10 +612,12 @@ static inline bool br_multicast_querier_exists(struct net_bridge *br,
{
switch (eth->h_proto) {
case (htons(ETH_P_IP)):
- return __br_multicast_querier_exists(br, &br->ip4_other_query);
+ return __br_multicast_querier_exists(br,
+ &br->ip4_other_query, false);
#if IS_ENABLED(CONFIG_IPV6)
case (htons(ETH_P_IPV6)):
- return __br_multicast_querier_exists(br, &br->ip6_other_query);
+ return __br_multicast_querier_exists(br,
+ &br->ip6_other_query, true);
#endif
default:
return false;