bridge: adhere to querier election mechanism specified by RFCs
MLDv1 (RFC2710 section 6), MLDv2 (RFC3810 section 7.6.2), IGMPv2
(RFC2236 section 3) and IGMPv3 (RFC3376 section 6.6.2) specify that the
querier with lowest source address shall become the selected
querier.
So far the bridge stopped its querier as soon as it heard another
querier regardless of its source address. This results in the "wrong"
querier potentially becoming the active querier or a potential,
unnecessary querying delay.
With this patch the bridge memorizes the source address of the currently
selected querier and ignores queries from queriers with a higher source
address than the currently selected one. This slight optimization is
supposed to make it more RFC compliant (but is rather uncritical and
therefore probably not necessary to be queued for stable kernels).
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2469aee..97c5e46 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -78,6 +78,11 @@
struct timer_list timer;
unsigned long delay_time;
};
+
+/* selected querier */
+struct bridge_mcast_querier {
+ struct br_ip addr;
+};
#endif
struct net_port_vlans {
@@ -284,9 +289,11 @@
struct timer_list multicast_router_timer;
struct bridge_mcast_other_query ip4_other_query;
struct bridge_mcast_own_query ip4_own_query;
+ struct bridge_mcast_querier ip4_querier;
#if IS_ENABLED(CONFIG_IPV6)
struct bridge_mcast_other_query ip6_other_query;
struct bridge_mcast_own_query ip6_own_query;
+ struct bridge_mcast_querier ip6_querier;
#endif /* IS_ENABLED(CONFIG_IPV6) */
#endif