1 files changed, 90 insertions, 0 deletions
diff --git a/dnsdist-session-cache.cc b/dnsdist-session-cache.cc
new file mode 100644
index 0000000..42ba272
--- /dev/null
+++ b/dnsdist-session-cache.cc
@@ -0,0 +1,90 @@
+/*
+ * 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.
+ */
+#include "dnsdist-session-cache.hh"
+
+TLSSessionCache g_sessionCache;
+
+time_t TLSSessionCache::s_cleanupDelay{60};
+time_t TLSSessionCache::s_sessionValidity{600};
+uint16_t TLSSessionCache::s_maxSessionsPerBackend{20};
+
+void TLSSessionCache::cleanup(time_t now, LockGuardedHolder<TLSSessionCache::CacheData>& data)
+{
+  time_t cutOff = now + s_sessionValidity;
+
+  for (auto it = data->d_sessions.begin(); it != data->d_sessions.end();) {
+    if (it->second.d_lastUsed > cutOff || it->second.d_sessions.size() == 0) {
+      it = data->d_sessions.erase(it);
+    }
+    else {
+      ++it;
+    }
+  }
+
+  data->d_nextCleanup = now + s_cleanupDelay;
+}
+
+void TLSSessionCache::putSessions(const boost::uuids::uuid& backendID, time_t now, std::vector<std::unique_ptr<TLSSession>>&& sessions)
+{
+  auto data = d_data.lock();
+  if (data->d_nextCleanup == 0 || now > data->d_nextCleanup) {
+    cleanup(now, data);
+  }
+
+  for (auto& session : sessions) {
+    auto& entry = data->d_sessions[backendID];
+    if (entry.d_sessions.size() >= s_maxSessionsPerBackend) {
+      entry.d_sessions.pop_back();
+    }
+    entry.d_sessions.push_front(std::move(session));
+  }
+}
+
+std::unique_ptr<TLSSession> TLSSessionCache::getSession(const boost::uuids::uuid& backendID, time_t now)
+{
+  auto data = d_data.lock();
+  auto it = data->d_sessions.find(backendID);
+  if (it == data->d_sessions.end()) {
+    return nullptr;
+  }
+
+  auto& entry = it->second;
+  if (entry.d_sessions.size() == 0) {
+    return nullptr;
+  }
+
+  entry.d_lastUsed = now;
+  auto value = std::move(entry.d_sessions.front());
+  entry.d_sessions.pop_front();
+
+  return value;
+}
+
+size_t TLSSessionCache::getSize()
+{
+  size_t count = 0;
+  auto data = d_data.lock();
+  for (const auto& backend : data->d_sessions) {
+    count += backend.second.d_sessions.size();
+  }
+  return count;
+}