+u32 inet_ehash_secret __read_mostly;
+EXPORT_SYMBOL(inet_ehash_secret);
+
+/*
+ * inet_ehash_secret must be set exactly once
+ * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
+ */
+void build_ehash_secret(void)
+{
+ u32 rnd;
+ do {
+ get_random_bytes(&rnd, sizeof(rnd));
+ } while (rnd == 0);
+ spin_lock_bh(&inetsw_lock);
+ if (!inet_ehash_secret)
+ inet_ehash_secret = rnd;
+ spin_unlock_bh(&inetsw_lock);
+}
+EXPORT_SYMBOL(build_ehash_secret);
+