[SCTP] Make init & delayed sack timeouts configurable by user.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 7fc3184..dc48934 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -47,6 +47,8 @@
 static ctl_handler sctp_sysctl_jiffies_ms;
 static long rto_timer_min = 1;
 static long rto_timer_max = 86400000; /* One day */
+static long sack_timer_min = 1;
+static long sack_timer_max = 500;
 
 static ctl_table sctp_table[] = {
 	{
@@ -187,6 +189,17 @@
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec
 	},
+	{
+		.ctl_name	= NET_SCTP_SACK_TIMEOUT,
+		.procname	= "sack_timeout",
+		.data		= &sctp_sack_timeout,
+		.maxlen		= sizeof(long),
+		.mode		= 0644,
+		.proc_handler	= &proc_doulongvec_ms_jiffies_minmax,
+		.strategy	= &sctp_sysctl_jiffies_ms,
+		.extra1         = &sack_timer_min,
+		.extra2         = &sack_timer_max,
+	},
 	{ .ctl_name = 0 }
 };