ipv4: implement igmp_qrv sysctl to tune igmp robustness variable
As in IPv6 people might increase the igmp query robustness variable to
make sure unsolicited state change reports aren't lost on the network. Add
and document this new knob to igmp code.
RFCs allow tuning this parameter back to first IGMP RFC, so we also use
this setting for all counters, including source specific multicast.
Also take over sysctl value when upping the interface and don't reuse
the last one seen on the interface.
Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 79a007c..45d156d 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -450,6 +450,16 @@
.mode = 0644,
.proc_handler = proc_dointvec
},
+#ifdef CONFIG_IP_MULTICAST
+ {
+ .procname = "igmp_qrv",
+ .data = &sysctl_igmp_qrv,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &one
+ },
+#endif
{
.procname = "inet_peer_threshold",
.data = &inet_peer_threshold,