1 files changed, 70 insertions, 6 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 16fc6f454a31..cca921ea8550 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2914,6 +2914,68 @@ static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
         return 0;
 }
 
+static void rt_secret_reschedule(int old)
+{
+        struct net *net;
+        int new = ip_rt_secret_interval;
+        int diff = new - old;
+
+        if (!diff)
+                return;
+
+        rtnl_lock();
+        for_each_net(net) {
+                int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
+
+                if (!new)
+                        continue;
+
+                if (deleted) {
+                        long time = net->ipv4.rt_secret_timer.expires - jiffies;
+
+                        if (time <= 0 || (time += diff) <= 0)
+                                time = 0;
+
+                        net->ipv4.rt_secret_timer.expires = time;
+                } else
+                        net->ipv4.rt_secret_timer.expires = new;
+
+                net->ipv4.rt_secret_timer.expires += jiffies;
+                add_timer(&net->ipv4.rt_secret_timer);
+        }
+        rtnl_unlock();
+}
+
+static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
+                                          struct file *filp,
+                                          void __user *buffer, size_t *lenp,
+                                          loff_t *ppos)
+{
+        int old = ip_rt_secret_interval;
+        int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
+
+        rt_secret_reschedule(old);
+
+        return ret;
+}
+
+static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
+                                                   int __user *name,
+                                                   int nlen,
+                                                   void __user *oldval,
+                                                   size_t __user *oldlenp,
+                                                   void __user *newval,
+                                                   size_t newlen)
+{
+        int old = ip_rt_secret_interval;
+        int ret = sysctl_jiffies(table, name, nlen, oldval, oldlenp, newval,
+                                 newlen);
+
+        rt_secret_reschedule(old);
+
+        return ret;
+}
+
 static ctl_table ipv4_route_table[] = {
         {
                 .ctl_name       = NET_IPV4_ROUTE_GC_THRESH,
@@ -3048,8 +3110,8 @@ static ctl_table ipv4_route_table[] = {
                 .data           = &ip_rt_secret_interval,
                 .maxlen         = sizeof(int),
                 .mode           = 0644,
-                .proc_handler   = &proc_dointvec_jiffies,
-                .strategy       = &sysctl_jiffies,
+                .proc_handler   = &ipv4_sysctl_rt_secret_interval,
+                .strategy       = &ipv4_sysctl_rt_secret_interval_strategy,
         },
         { .ctl_name = 0 }
 };
@@ -3126,10 +3188,12 @@ static __net_init int rt_secret_timer_init(struct net *net)
         net->ipv4.rt_secret_timer.data = (unsigned long)net;
         init_timer_deferrable(&net->ipv4.rt_secret_timer);
 
-        net->ipv4.rt_secret_timer.expires =
-                jiffies + net_random() % ip_rt_secret_interval +
-                ip_rt_secret_interval;
-        add_timer(&net->ipv4.rt_secret_timer);
+        if (ip_rt_secret_interval) {
+                net->ipv4.rt_secret_timer.expires =
+                        jiffies + net_random() % ip_rt_secret_interval +
+                        ip_rt_secret_interval;
+                add_timer(&net->ipv4.rt_secret_timer);
+        }
         return 0;
 }