1 files changed, 35 insertions, 0 deletions

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 534eaa8cdcf3..ec10e05c6666 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -16,9 +16,38 @@
 #include <linux/module.h>
 #include <linux/timer.h>
 #include <linux/mm.h>
+#include <linux/random.h>
 
 #include <net/inet_frag.h>
 
+static void inet_frag_secret_rebuild(unsigned long dummy)
+{
+        struct inet_frags *f = (struct inet_frags *)dummy;
+        unsigned long now = jiffies;
+        int i;
+
+        write_lock(&f->lock);
+        get_random_bytes(&f->rnd, sizeof(u32));
+        for (i = 0; i < INETFRAGS_HASHSZ; i++) {
+                struct inet_frag_queue *q;
+                struct hlist_node *p, *n;
+
+                hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) {
+                        unsigned int hval = f->hashfn(q);
+
+                        if (hval != i) {
+                                hlist_del(&q->list);
+
+                                /* Relink to new hash chain. */
+                                hlist_add_head(&q->list, &f->hash[hval]);
+                        }
+                }
+        }
+        write_unlock(&f->lock);
+
+        mod_timer(&f->secret_timer, now + f->ctl->secret_interval);
+}
+
 void inet_frags_init(struct inet_frags *f)
 {
         int i;
@@ -35,11 +64,17 @@ void inet_frags_init(struct inet_frags *f)
         f->nqueues = 0;
         atomic_set(&f->mem, 0);
 
+        init_timer(&f->secret_timer);
+        f->secret_timer.function = inet_frag_secret_rebuild;
+        f->secret_timer.data = (unsigned long)f;
+        f->secret_timer.expires = jiffies + f->ctl->secret_interval;
+        add_timer(&f->secret_timer);
 }
 EXPORT_SYMBOL(inet_frags_init);
 
 void inet_frags_fini(struct inet_frags *f)
 {
+        del_timer(&f->secret_timer);
 }
 EXPORT_SYMBOL(inet_frags_fini);