ipv4/igmp: fix v1/v2 switchback timeout based on rfc3376, 8.12
Similiar with ipv6 mcast commit 89225d1ce6af3 ("net: ipv6: mld: fix v1/v2
switchback timeout to rfc3810, 9.12.")
i) RFC3376 8.12. Older Version Querier Present Timeout says:
The Older Version Querier Interval is the time-out for transitioning
a host back to IGMPv3 mode once an older version query is heard.
When an older version query is received, hosts set their Older
Version Querier Present Timer to Older Version Querier Interval.
This value MUST be ((the Robustness Variable) times (the Query
Interval in the last Query received)) plus (one Query Response
Interval).
Currently we only use a hardcode value IGMP_V1/v2_ROUTER_PRESENT_TIMEOUT.
Fix it by adding two new items mr_qi(Query Interval) and mr_qri(Query Response
Interval) in struct in_device.
Now we can calculate the switchback time via (mr_qrv * mr_qi) + mr_qri.
We need update these values when receive IGMPv3 queries.
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index c759d1c..a64f21a 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -37,7 +37,9 @@ struct in_device {
unsigned long mr_v1_seen;
unsigned long mr_v2_seen;
unsigned long mr_maxdelay;
- unsigned char mr_qrv;
+ unsigned long mr_qi; /* Query Interval */
+ unsigned long mr_qri; /* Query Response Interval */
+ unsigned char mr_qrv; /* Query Robustness Variable */
unsigned char mr_gq_running;
unsigned char mr_ifc_count;
struct timer_list mr_gq_timer; /* general query timer */