1 files changed, 73 insertions, 3 deletions

diff --git a/MediaBrowser.Common.Implementations/Networking/BaseNetworkManager.cs b/MediaBrowser.Common.Implementations/Networking/BaseNetworkManager.cs
index bf6ebf7ef..6deda1293 100644
--- a/MediaBrowser.Common.Implementations/Networking/BaseNetworkManager.cs
+++ b/MediaBrowser.Common.Implementations/Networking/BaseNetworkManager.cs
@@ -18,12 +18,65 @@ namespace MediaBrowser.Common.Implementations.Networking
             Logger = logger;
         }
 
+        private volatile List<string> _localIpAddresses;
+        private readonly object _localIpAddressSyncLock = new object();
+
         /// <summary>
         /// Gets the machine's local ip address
         /// </summary>
         /// <returns>IPAddress.</returns>
         public IEnumerable<string> GetLocalIpAddresses()
         {
+            if (_localIpAddresses == null)
+            {
+                lock (_localIpAddressSyncLock)
+                {
+                    if (_localIpAddresses == null)
+                    {
+                        var addresses = GetLocalIpAddressesInternal().ToList();
+
+                        _localIpAddresses = addresses;
+                        BindEvents();
+
+                        return addresses;
+                    }
+                }
+            }
+
+            return _localIpAddresses;
+        }
+
+        private void BindEvents()
+        {
+            NetworkChange.NetworkAddressChanged -= NetworkChange_NetworkAddressChanged;
+            NetworkChange.NetworkAvailabilityChanged -= NetworkChange_NetworkAvailabilityChanged;
+
+            NetworkChange.NetworkAddressChanged += NetworkChange_NetworkAddressChanged;
+            NetworkChange.NetworkAvailabilityChanged += NetworkChange_NetworkAvailabilityChanged;
+        }
+
+        void NetworkChange_NetworkAvailabilityChanged(object sender, NetworkAvailabilityEventArgs e)
+        {
+            Logger.Debug("NetworkAvailabilityChanged fired. Resetting cached network info.");
+
+            lock (_localIpAddressSyncLock)
+            {
+                _localIpAddresses = null;
+            }
+        }
+
+        void NetworkChange_NetworkAddressChanged(object sender, EventArgs e)
+        {
+            Logger.Debug("NetworkAddressChanged fired. Resetting cached network info.");
+
+            lock (_localIpAddressSyncLock)
+            {
+                _localIpAddresses = null;
+            }
+        }
+
+        private IEnumerable<string> GetLocalIpAddressesInternal()
+        {
             var list = GetIPsDefault()
                 .Where(i => !IPAddress.IsLoopback(i))
                 .Select(i => i.ToString())
@@ -53,6 +106,11 @@ namespace MediaBrowser.Common.Implementations.Networking
             // Private address space:
             // http://en.wikipedia.org/wiki/Private_network
 
+            if (endpoint.StartsWith("172.", StringComparison.OrdinalIgnoreCase))
+            {
+                return Is172AddressPrivate(endpoint);
+            }
+
             return
 
                 // If url was requested with computer name, we may see this
@@ -61,11 +119,23 @@ namespace MediaBrowser.Common.Implementations.Networking
                 endpoint.StartsWith("localhost", StringComparison.OrdinalIgnoreCase) ||
                 endpoint.StartsWith("127.", StringComparison.OrdinalIgnoreCase) ||
                 endpoint.StartsWith("10.", StringComparison.OrdinalIgnoreCase) ||
-                endpoint.StartsWith("192.", StringComparison.OrdinalIgnoreCase) ||
-                endpoint.StartsWith("172.", StringComparison.OrdinalIgnoreCase) ||
+                endpoint.StartsWith("192.168", StringComparison.OrdinalIgnoreCase) ||
                 endpoint.StartsWith("169.", StringComparison.OrdinalIgnoreCase);
         }
 
+        private bool Is172AddressPrivate(string endpoint)
+        {
+            for (var i = 16; i <= 31; i++)
+            {
+                if (endpoint.StartsWith("172." + i.ToString(CultureInfo.InvariantCulture) + ".", StringComparison.OrdinalIgnoreCase))
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
         public bool IsInLocalNetwork(string endpoint)
         {
             return IsInLocalNetworkInternal(endpoint, true);
@@ -122,7 +192,7 @@ namespace MediaBrowser.Common.Implementations.Networking
 
             return false;
         }
-        
+
         public IEnumerable<IPAddress> GetIpAddresses(string hostName)
         {
             return Dns.GetHostAddresses(hostName);