1 files changed, 75 insertions, 0 deletions
diff --git a/dnsdist-mac-address.cc b/dnsdist-mac-address.cc
new file mode 100644
index 0000000..20a7245
--- /dev/null
+++ b/dnsdist-mac-address.cc
@@ -0,0 +1,75 @@
+/*
+ * 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-mac-address.hh"
+#include "misc.hh"
+
+namespace dnsdist
+{
+LockGuarded<boost::circular_buffer<MacAddressesCache::Entry>> MacAddressesCache::s_cache;
+
+int MacAddressesCache::get(const ComboAddress& ca, unsigned char* dest, size_t destLen)
+{
+  if (dest == nullptr || destLen < sizeof(Entry::mac)) {
+    return EINVAL;
+  }
+
+  auto compare = ComboAddress::addressOnlyEqual();
+  time_t now = time(nullptr);
+
+  {
+    auto cache = s_cache.lock();
+    for (const auto& entry : *cache) {
+      if (entry.ttd >= now && compare(entry.ca, ca) == true) {
+        if (!entry.found) {
+          // negative entry
+          return ENOENT;
+        }
+        memcpy(dest, entry.mac.data(), entry.mac.size());
+        return 0;
+      }
+    }
+  }
+
+  auto res = getMACAddress(ca, reinterpret_cast<char*>(dest), destLen);
+  {
+    auto cache = s_cache.lock();
+    if (cache->capacity() == 0) {
+      cache->set_capacity(MacAddressesCache::s_cacheSize);
+    }
+    Entry entry;
+    entry.ca = ca;
+    if (res == 0) {
+      memcpy(entry.mac.data(), dest, entry.mac.size());
+      entry.found = true;
+    }
+    else {
+      memset(entry.mac.data(), 0, entry.mac.size());
+      entry.found = false;
+    }
+    entry.ttd = now + MacAddressesCache::s_cacheValiditySeconds;
+    cache->push_back(std::move(entry));
+  }
+
+  return res;
+}
+}