1 files changed, 114 insertions, 0 deletions
diff --git a/xbmc/network/DNSNameCache.cpp b/xbmc/network/DNSNameCache.cpp
new file mode 100644
index 0000000..af2ac1a
--- /dev/null
+++ b/xbmc/network/DNSNameCache.cpp
@@ -0,0 +1,114 @@
+/*
+ *  Copyright (C) 2005-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#include "DNSNameCache.h"
+
+#include "threads/CriticalSection.h"
+#include "utils/StringUtils.h"
+#include "utils/log.h"
+
+#include <mutex>
+
+#if !defined(TARGET_WINDOWS) && defined(HAS_FILESYSTEM_SMB)
+#include "ServiceBroker.h"
+
+#include "platform/posix/filesystem/SMBWSDiscovery.h"
+#endif
+
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+
+CDNSNameCache g_DNSCache;
+
+CCriticalSection CDNSNameCache::m_critical;
+
+CDNSNameCache::CDNSNameCache(void) = default;
+
+CDNSNameCache::~CDNSNameCache(void) = default;
+
+bool CDNSNameCache::Lookup(const std::string& strHostName, std::string& strIpAddress)
+{
+  if (strHostName.empty() && strIpAddress.empty())
+    return false;
+
+  // first see if this is already an ip address
+  unsigned long address = inet_addr(strHostName.c_str());
+  strIpAddress.clear();
+
+  if (address != INADDR_NONE)
+  {
+    strIpAddress = StringUtils::Format("{}.{}.{}.{}", (address & 0xFF), (address & 0xFF00) >> 8,
+                                       (address & 0xFF0000) >> 16, (address & 0xFF000000) >> 24);
+    return true;
+  }
+
+  // check if there's a custom entry or if it's already cached
+  if(g_DNSCache.GetCached(strHostName, strIpAddress))
+    return true;
+
+  // perform dns lookup
+  struct hostent *host = gethostbyname(strHostName.c_str());
+  if (host && host->h_addr_list[0])
+  {
+    strIpAddress = StringUtils::Format("{}.{}.{}.{}", (unsigned char)host->h_addr_list[0][0],
+                                       (unsigned char)host->h_addr_list[0][1],
+                                       (unsigned char)host->h_addr_list[0][2],
+                                       (unsigned char)host->h_addr_list[0][3]);
+    g_DNSCache.Add(strHostName, strIpAddress);
+    return true;
+  }
+
+  CLog::Log(LOGERROR, "Unable to lookup host: '{}'", strHostName);
+  return false;
+}
+
+bool CDNSNameCache::GetCached(const std::string& strHostName, std::string& strIpAddress)
+{
+  {
+    std::unique_lock<CCriticalSection> lock(m_critical);
+
+    // loop through all DNSname entries and see if strHostName is cached
+    for (const auto& DNSname : g_DNSCache.m_vecDNSNames)
+    {
+      if (DNSname.m_strHostName == strHostName)
+      {
+        strIpAddress = DNSname.m_strIpAddress;
+        return true;
+      }
+    }
+  }
+
+#if !defined(TARGET_WINDOWS) && defined(HAS_FILESYSTEM_SMB)
+  if (WSDiscovery::CWSDiscoveryPosix::IsInitialized())
+  {
+    WSDiscovery::CWSDiscoveryPosix& WSInstance =
+        dynamic_cast<WSDiscovery::CWSDiscoveryPosix&>(CServiceBroker::GetWSDiscovery());
+    if (WSInstance.GetCached(strHostName, strIpAddress))
+      return true;
+  }
+  else
+    CLog::Log(LOGDEBUG, LOGWSDISCOVERY,
+              "CDNSNameCache::GetCached: CWSDiscoveryPosix not initialized");
+#endif
+
+  // not cached
+  return false;
+}
+
+void CDNSNameCache::Add(const std::string& strHostName, const std::string& strIpAddress)
+{
+  CDNSName dnsName;
+
+  dnsName.m_strHostName = strHostName;
+  dnsName.m_strIpAddress  = strIpAddress;
+
+  std::unique_lock<CCriticalSection> lock(m_critical);
+  g_DNSCache.m_vecDNSNames.push_back(dnsName);
+}
+