1 files changed, 78 insertions, 0 deletions
diff --git a/dnsdist-discovery.hh b/dnsdist-discovery.hh
new file mode 100644
index 0000000..ceb2d2c
--- /dev/null
+++ b/dnsdist-discovery.hh
@@ -0,0 +1,78 @@
+/*
+ * 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 <vector>
+#include <thread>
+
+#include "dnsname.hh"
+#include "dnsdist-protocols.hh"
+#include "iputils.hh"
+#include "lock.hh"
+
+struct DownstreamState;
+
+namespace dnsdist
+{
+
+class ServiceDiscovery
+{
+public:
+  static bool addUpgradeableServer(std::shared_ptr<DownstreamState>& server, uint32_t interval, std::string poolAfterUpgrade, uint16_t dohSVCKey, bool keepAfterUpgrade);
+
+  /* starts a background thread if needed */
+  static bool run();
+
+  struct DiscoveredResolverConfig
+  {
+    ComboAddress d_addr;
+    std::string d_subjectName;
+    std::string d_dohPath;
+    uint16_t d_port{0};
+    dnsdist::Protocol d_protocol;
+  };
+
+  static const uint16_t s_defaultDoHSVCKey;
+
+private:
+  static const DNSName s_discoveryDomain;
+  static const QType s_discoveryType;
+
+  struct UpgradeableBackend
+  {
+    std::shared_ptr<DownstreamState> d_ds;
+    std::string d_poolAfterUpgrade;
+    time_t d_nextCheck;
+    uint32_t d_interval;
+    uint16_t d_dohKey;
+    bool keepAfterUpgrade;
+  };
+
+  static bool getDiscoveredConfig(const UpgradeableBackend& backend, DiscoveredResolverConfig& config);
+  static bool tryToUpgradeBackend(const UpgradeableBackend& backend);
+
+  static void worker();
+
+  static LockGuarded<std::vector<std::shared_ptr<UpgradeableBackend>>> s_upgradeableBackends;
+  static std::thread s_thread;
+};
+
+}