Ratelimit nochannel ADNL packets (#1147)

* Get ADNL stats in validator console

* Add timestamp to stats

* Limit nochannel adnl packets

---------

Co-authored-by: SpyCheese <mikle98@yandex.ru>

adnl/utils.hpp

@@ -40,6 +40,40 @@ inline bool adnl_node_is_older(AdnlNode &a, AdnlNode &b) {
   return a.addr_list().version() < b.addr_list().version();
 }
 
+class RateLimiter {
+public:
+  explicit RateLimiter(td::uint32 capacity, double period) : capacity_(capacity), period_(period), remaining_(capacity) {
+  }
+
+  bool take() {
+    while (remaining_ < capacity_ && increment_at_.is_in_past()) {
+      ++remaining_;
+      increment_at_ += period_;
+    }
+    if (remaining_) {
+      --remaining_;
+      if (increment_at_.is_in_past()) {
+        increment_at_ = td::Timestamp::in(period_);
+      }
+      return true;
+    }
+    return false;
+  }
+
+  td::Timestamp ready_at() const {
+    if (remaining_) {
+      return td::Timestamp::now();
+    }
+    return increment_at_;
+  }
+
+private:
+  td::uint32 capacity_;
+  double period_;
+  td::uint32 remaining_;
+  td::Timestamp increment_at_ = td::Timestamp::never();
+};
+
 }  // namespace adnl
 
 }  // namespace ton