2 files changed, 34 insertions, 6 deletions

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index e14d244c551f..9ba72d94d60f 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -47,6 +47,7 @@ struct fib6_cleaner {
         int (*func)(struct fib6_info *, void *arg);
         int sernum;
         void *arg;
+        bool skip_notify;
 };
 
 #ifdef CONFIG_IPV6_SUBTREES
@@ -1956,6 +1957,7 @@ static int fib6_clean_node(struct fib6_walker *w)
         struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
         struct nl_info info = {
                 .nl_net = c->net,
+                .skip_notify = c->skip_notify,
         };
 
         if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
@@ -2007,7 +2009,7 @@ static int fib6_clean_node(struct fib6_walker *w)
 
 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
                             int (*func)(struct fib6_info *, void *arg),
-                            int sernum, void *arg)
+                            int sernum, void *arg, bool skip_notify)
 {
         struct fib6_cleaner c;
 
@@ -2019,13 +2021,14 @@ static void fib6_clean_tree(struct net *net, struct fib6_node *root,
         c.sernum = sernum;
         c.arg = arg;
         c.net = net;
+        c.skip_notify = skip_notify;
 
         fib6_walk(net, &c.w);
 }
 
 static void __fib6_clean_all(struct net *net,
                              int (*func)(struct fib6_info *, void *),
-                             int sernum, void *arg)
+                             int sernum, void *arg, bool skip_notify)
 {
         struct fib6_table *table;
         struct hlist_head *head;
@@ -2037,7 +2040,7 @@ static void __fib6_clean_all(struct net *net,
                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
                         spin_lock_bh(&table->tb6_lock);
                         fib6_clean_tree(net, &table->tb6_root,
-                                        func, sernum, arg);
+                                        func, sernum, arg, skip_notify);
                         spin_unlock_bh(&table->tb6_lock);
                 }
         }
@@ -2047,14 +2050,21 @@ static void __fib6_clean_all(struct net *net,
 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *),
                     void *arg)
 {
-        __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
+        __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false);
+}
+
+void fib6_clean_all_skip_notify(struct net *net,
+                                int (*func)(struct fib6_info *, void *),
+                                void *arg)
+{
+        __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true);
 }
 
 static void fib6_flush_trees(struct net *net)
 {
         int new_sernum = fib6_new_sernum(net);
 
-        __fib6_clean_all(net, NULL, new_sernum, NULL);
+        __fib6_clean_all(net, NULL, new_sernum, NULL, false);
 }
 
 /*
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index bf4cd647d8b8..f4e08b0689a8 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -4026,8 +4026,12 @@ void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
                         .event = event,
                 },
         };
+        struct net *net = dev_net(dev);
 
-        fib6_clean_all(dev_net(dev), fib6_ifdown, &arg);
+        if (net->ipv6.sysctl.skip_notify_on_dev_down)
+                fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
+        else
+                fib6_clean_all(net, fib6_ifdown, &arg);
 }
 
 void rt6_disable_ip(struct net_device *dev, unsigned long event)
@@ -5031,6 +5035,9 @@ int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
         return 0;
 }
 
+static int zero;
+static int one = 1;
+
 static struct ctl_table ipv6_route_table_template[] = {
         {
                 .procname       =       "flush",
@@ -5102,6 +5109,15 @@ static struct ctl_table ipv6_route_table_template[] = {
                 .mode           =       0644,
                 .proc_handler   =       proc_dointvec_ms_jiffies,
         },
+        {
+                .procname       =       "skip_notify_on_dev_down",
+                .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
+                .maxlen         =       sizeof(int),
+                .mode           =       0644,
+                .proc_handler   =       proc_dointvec,
+                .extra1         =       &zero,
+                .extra2         =       &one,
+        },
         { }
 };
 
@@ -5125,6 +5141,7 @@ struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
+                table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
 
                 /* Don't export sysctls to unprivileged users */
                 if (net->user_ns != &init_user_ns)
@@ -5189,6 +5206,7 @@ static int __net_init ip6_route_net_init(struct net *net)
         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
+        net->ipv6.sysctl.skip_notify_on_dev_down = 0;
 
         net->ipv6.ip6_rt_gc_expire = 30*HZ;