summaryrefslogtreecommitdiffstats
path: root/dnsdist-concurrent-connections.hh
diff options
context:
space:
mode:
Diffstat (limited to 'dnsdist-concurrent-connections.hh')
-rw-r--r--dnsdist-concurrent-connections.hh70
1 files changed, 70 insertions, 0 deletions
diff --git a/dnsdist-concurrent-connections.hh b/dnsdist-concurrent-connections.hh
new file mode 100644
index 0000000..3cf55d5
--- /dev/null
+++ b/dnsdist-concurrent-connections.hh
@@ -0,0 +1,70 @@
+/*
+ * This file is part of PowerDNS or dnsdist.
+ * Copyright -- PowerDNS.COM B.V. and its contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * In addition, for the avoidance of any doubt, permission is granted to
+ * link this program with OpenSSL and to (re)distribute the binaries
+ * produced as the result of such linking.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#pragma once
+
+#include <map>
+#include "iputils.hh"
+#include "lock.hh"
+
+namespace dnsdist
+{
+class IncomingConcurrentTCPConnectionsManager
+{
+public:
+ static bool accountNewTCPConnection(const ComboAddress& from)
+ {
+ if (s_maxTCPConnectionsPerClient == 0) {
+ return true;
+ }
+ auto db = s_tcpClientsConcurrentConnectionsCount.lock();
+ auto& count = (*db)[from];
+ if (count >= s_maxTCPConnectionsPerClient) {
+ return false;
+ }
+ ++count;
+ return true;
+ }
+
+ static void accountClosedTCPConnection(const ComboAddress& from)
+ {
+ if (s_maxTCPConnectionsPerClient == 0) {
+ return;
+ }
+ auto db = s_tcpClientsConcurrentConnectionsCount.lock();
+ auto& count = db->at(from);
+ count--;
+ if (count == 0) {
+ db->erase(from);
+ }
+ }
+
+ static void setMaxTCPConnectionsPerClient(size_t max)
+ {
+ s_maxTCPConnectionsPerClient = max;
+ }
+
+private:
+ static LockGuarded<std::map<ComboAddress, size_t, ComboAddress::addressOnlyLessThan>> s_tcpClientsConcurrentConnectionsCount;
+ static size_t s_maxTCPConnectionsPerClient;
+};
+
+}