bridge: use the bridge IP addr as source addr for querier
Quote from Adam:
"If it is believed that the use of 0.0.0.0
as the IP address is what is causing strange behaviour on other devices
then is there a good reason that a bridge rather than a router shouldn't
be the active querier? If not then using the bridge IP address and
having the querier enabled by default may be a reasonable solution
(provided that our querier obeys the election rules and shuts up if it
sees a query from a lower IP address that isn't 0.0.0.0). Just because a
device is the elected querier for IGMP doesn't appear to mean it is
required to perform any other routing functions."
And introduce a new troggle for it, as suggested by Herbert.
Suggested-by: Adam Baker <linux@baker-net.org.uk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Adam Baker <linux@baker-net.org.uk>
Signed-off-by: Cong Wang <amwang@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 81f2389..2475147 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -23,6 +23,7 @@
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/timer.h>
+#include <linux/inetdevice.h>
#include <net/ip.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
@@ -381,7 +382,8 @@
iph->frag_off = htons(IP_DF);
iph->ttl = 1;
iph->protocol = IPPROTO_IGMP;
- iph->saddr = 0;
+ iph->saddr = br->multicast_query_use_ifaddr ?
+ inet_select_addr(br->dev, 0, RT_SCOPE_LINK) : 0;
iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
((u8 *)&iph[1])[0] = IPOPT_RA;
((u8 *)&iph[1])[1] = 4;
@@ -1618,6 +1620,7 @@
br->multicast_router = 1;
br->multicast_querier = 0;
+ br->multicast_query_use_ifaddr = 0;
br->multicast_last_member_count = 2;
br->multicast_startup_query_count = 2;