Updated PR1 code.

4 files changed, 92 insertions, 105 deletions

diff --git a/MediaBrowser.Common/Net/INetworkManager.cs b/MediaBrowser.Common/Net/INetworkManager.cs
index a7beabbdc..43562afe3 100644
--- a/MediaBrowser.Common/Net/INetworkManager.cs
+++ b/MediaBrowser.Common/Net/INetworkManager.cs
@@ -1,10 +1,11 @@
 #nullable enable
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Net;
 using System.Net.NetworkInformation;
+using MediaBrowser.Common.Net;
 using Microsoft.AspNetCore.Http;
-using NetCollection = System.Collections.ObjectModel.Collection<MediaBrowser.Common.Net.IPObject>;
 
 namespace MediaBrowser.Common.Net
 {
@@ -31,7 +32,7 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Gets the remote address filter.
         /// </summary>
-        NetCollection RemoteAddressFilter { get; }
+        Collection<IPObject> RemoteAddressFilter { get; }
 
         /// <summary>
         /// Gets or sets a value indicating whether iP6 is enabled.
@@ -46,17 +47,17 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Calculates the list of interfaces to use for Kestrel.
         /// </summary>
-        /// <returns>A NetCollection object containing all the interfaces to bind.
+        /// <returns>A Collection{IPObject} object containing all the interfaces to bind.
         /// If all the interfaces are specified, and none are excluded, it returns zero items
         /// to represent any address.</returns>
         /// <param name="individualInterfaces">When false, return <see cref="IPAddress.Any"/> or <see cref="IPAddress.IPv6Any"/> for all interfaces.</param>
-        NetCollection GetAllBindInterfaces(bool individualInterfaces = false);
+        Collection<IPObject> GetAllBindInterfaces(bool individualInterfaces = false);
 
         /// <summary>
         /// Returns a collection containing the loopback interfaces.
         /// </summary>
-        /// <returns>Netcollection.</returns>
-        NetCollection GetLoopbacks();
+        /// <returns>Collection{IPObject}.</returns>
+        Collection<IPObject> GetLoopbacks();
 
         /// <summary>
         /// Retrieves the bind address to use in system url's. (Server Discovery, PlayTo, LiveTV, SystemInfo)
@@ -137,7 +138,14 @@ namespace MediaBrowser.Common.Net
         /// </summary>
         /// <param name="addressObj">IP to check. Can be an IPAddress or an IPObject.</param>
         /// <returns>Result of the check.</returns>
-        bool IsGatewayInterface(object? addressObj);
+        bool IsGatewayInterface(IPObject? addressObj);
+
+        /// <summary>
+        /// Checks to see if the IP Address provided matches an interface that has a gateway.
+        /// </summary>
+        /// <param name="addressObj">IP to check. Can be an IPAddress or an IPObject.</param>
+        /// <returns>Result of the check.</returns>
+        bool IsGatewayInterface(IPAddress? addressObj);
 
         /// <summary>
         /// Returns true if the address is a private address.
@@ -178,21 +186,21 @@ namespace MediaBrowser.Common.Net
         /// <param name="token">Token to parse.</param>
         /// <param name="result">Resultant object's ip addresses, if successful.</param>
         /// <returns>Success of the operation.</returns>
-        bool TryParseInterface(string token, out NetCollection? result);
+        bool TryParseInterface(string token, out Collection<IPObject>? result);
 
         /// <summary>
-        /// Parses an array of strings into a NetCollection.
+        /// Parses an array of strings into a Collection{IPObject}.
         /// </summary>
         /// <param name="values">Values to parse.</param>
         /// <param name="bracketed">When true, only include values in []. When false, ignore bracketed values.</param>
         /// <returns>IPCollection object containing the value strings.</returns>
-        NetCollection CreateIPCollection(string[] values, bool bracketed = false);
+        Collection<IPObject> CreateIPCollection(string[] values, bool bracketed = false);
 
         /// <summary>
         /// Returns all the internal Bind interface addresses.
         /// </summary>
         /// <returns>An internal list of interfaces addresses.</returns>
-        NetCollection GetInternalBindAddresses();
+        Collection<IPObject> GetInternalBindAddresses();
 
         /// <summary>
         /// Checks to see if an IP address is still a valid interface address.
@@ -220,12 +228,6 @@ namespace MediaBrowser.Common.Net
         /// </summary>
         /// <param name="filter">Optional filter for the list.</param>
         /// <returns>Returns a filtered list of LAN addresses.</returns>
-        NetCollection GetFilteredLANSubnets(NetCollection? filter = null);
-
-        /// <summary>
-        /// Reloads all settings and re-initialises the instance.
-        /// </summary>
-        /// <param name="configuration">The configuration to use.</param>
-        void UpdateSettings(object configuration);
+        Collection<IPObject> GetFilteredLANSubnets(Collection<IPObject>? filter = null);
     }
 }
diff --git a/MediaBrowser.Common/Net/IPHost.cs b/MediaBrowser.Common/Net/IPHost.cs
index 80052727a..f9e1568ef 100644
--- a/MediaBrowser.Common/Net/IPHost.cs
+++ b/MediaBrowser.Common/Net/IPHost.cs
@@ -19,7 +19,7 @@ namespace MediaBrowser.Common.Net
         public static readonly IPHost None = new IPHost(string.Empty, IPAddress.None);
 
         /// <summary>
-        /// Time when last resolved.
+        /// Time when last resolved in ticks.
         /// </summary>
         private long _lastResolved;
 
@@ -63,7 +63,8 @@ namespace MediaBrowser.Common.Net
 
             set
             {
-                // Not implemented.
+                // Not implemented, as a host's address is determined by DNS.
+                throw new NotImplementedException("The address of a host is determined by DNS.");
             }
         }
 
@@ -75,12 +76,14 @@ namespace MediaBrowser.Common.Net
         {
             get
             {
-                return (byte)(ResolveHost() ? 128 : 0);
+                return (byte)(ResolveHost() ? 128 : 32);
             }
 
             set
             {
-                // Not implemented.
+                // Not implemented, as a host object can only have a prefix length of 128 (IPv6) or 32 (IPv4) prefix length,
+                // which is automatically determined by it's IP type. Anything else is meaningless.
+                throw new NotImplementedException("The prefix length on a host cannot be set.");
             }
         }
 
@@ -92,13 +95,7 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Gets a value indicating whether the address has a value.
         /// </summary>
-        public bool HasAddress
-        {
-            get
-            {
-                return _addresses.Length > 0;
-            }
-        }
+        public bool HasAddress => _addresses.Length != 0;
 
         /// <summary>
         /// Gets the host name of this object.
@@ -128,7 +125,7 @@ namespace MediaBrowser.Common.Net
         /// </summary>
         /// <param name="host">Host name to parse.</param>
         /// <param name="hostObj">Object representing the string, if it has successfully been parsed.</param>
-        /// <returns>Success result of the parsing.</returns>
+        /// <returns><c>true</c> if the parsing is successful, <c>false</c> if not.</returns>
         public static bool TryParse(string host, out IPHost hostObj)
         {
             if (!string.IsNullOrEmpty(host))
@@ -142,7 +139,7 @@ namespace MediaBrowser.Common.Net
                 else
                 {
                     // See if it's an IPv6 in [] with no port.
-                    i = host.IndexOf("]", StringComparison.OrdinalIgnoreCase);
+                    i = host.IndexOf(']', StringComparison.OrdinalIgnoreCase);
                     if (i != -1)
                     {
                         return TryParse(host.Remove(i - 1).TrimStart(' ', '['), out hostObj);
@@ -394,19 +391,19 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Attempt to resolve the ip address of a host.
         /// </summary>
-        /// <returns>The result of the comparison function.</returns>
+        /// <returns><c>true</c> if any addresses have been resolved, otherwise <c>false</c>.</returns>
         private bool ResolveHost()
         {
             // When was the last time we resolved?
             if (_lastResolved == 0)
             {
-                _lastResolved = DateTime.Now.Ticks;
+                _lastResolved = DateTime.UtcNow.Ticks;
             }
 
             // If we haven't resolved before, or out timer has run out...
-            if ((_addresses.Length == 0 && !Resolved) || (TimeSpan.FromTicks(DateTime.Now.Ticks - _lastResolved).TotalMinutes > Timeout))
+            if ((_addresses.Length == 0 && !Resolved) || (TimeSpan.FromTicks(DateTime.UtcNow.Ticks - _lastResolved).TotalMinutes > Timeout))
             {
-                _lastResolved = DateTime.Now.Ticks;
+                _lastResolved = DateTime.UtcNow.Ticks;
                 ResolveHostInternal().GetAwaiter().GetResult();
                 Resolved = true;
             }
@@ -417,7 +414,7 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Task that looks up a Host name and returns its IP addresses.
         /// </summary>
-        /// <returns>Array of IPAddress objects.</returns>
+        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
         private async Task ResolveHostInternal()
         {
             if (!string.IsNullOrEmpty(HostName))
diff --git a/MediaBrowser.Common/Net/IPObject.cs b/MediaBrowser.Common/Net/IPObject.cs
index 36f3357cc..d18ac9893 100644
--- a/MediaBrowser.Common/Net/IPObject.cs
+++ b/MediaBrowser.Common/Net/IPObject.cs
@@ -26,7 +26,7 @@ namespace MediaBrowser.Common.Net
         private IPObject? _networkAddress;
 
         /// <summary>
-        /// Gets or sets the user defined functions that need storage in this object.
+        /// Gets or sets a user defined value that is associated with this object.
         /// </summary>
         public int Tag { get; set; }
 
@@ -38,18 +38,7 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Gets the object's network address.
         /// </summary>
-        public IPObject NetworkAddress
-        {
-            get
-            {
-                if (_networkAddress == null)
-                {
-                    _networkAddress = CalculateNetworkAddress();
-                }
-
-                return _networkAddress;
-            }
-        }
+        public IPObject NetworkAddress => _networkAddress ??= CalculateNetworkAddress();
 
         /// <summary>
         /// Gets or sets the object's IP address.
@@ -92,22 +81,33 @@ namespace MediaBrowser.Common.Net
                 return (Address: address, PrefixLength: prefixLength);
             }
 
+            // An ip address is just a list of bytes, each one representing a segment on the network.
+            // This separates the IP address into octets and calculates how many octets will need to be altered or set to zero dependant upon the
+            // prefix length value. eg. /16 on a 4 octet ip4 address (192.168.2.240) will result in the 2 and the 240 being zeroed out.
+            // Where there is not an exact boundary (eg /23), mod is used to calculate how many bits of this value are to be kept.
+
             byte[] addressBytes = address.GetAddressBytes();
 
             int div = prefixLength / 8;
             int mod = prefixLength % 8;
             if (mod != 0)
             {
+                // Prefix length is counted right to left, so subtract 8 so we know how many bits to clear.
                 mod = 8 - mod;
+
+                // Shift out the bits from the octet that we don't want, by moving right then back left.
                 addressBytes[div] = (byte)((int)addressBytes[div] >> mod << mod);
+                // Move on the next byte.
                 div++;
             }
 
+            // Blank out the remaining octets from mod + 1 to the end of the byte array. (192.168.2.240/16 becomes 192.168.0.0)
             for (int octet = div; octet < addressBytes.Length; octet++)
             {
                 addressBytes[octet] = 0;
             }
 
+            // Return the network address for the prefix.
             return (Address: new IPAddress(addressBytes), PrefixLength: prefixLength);
         }
 
@@ -179,18 +179,18 @@ namespace MediaBrowser.Common.Net
 
                     byte[] octet = address.GetAddressBytes();
 
-                    return (octet[0] == 10) ||
-                        (octet[0] == 172 && octet[1] >= 16 && octet[1] <= 31) || // RFC1918
-                        (octet[0] == 192 && octet[1] == 168) || // RFC1918
-                        (octet[0] == 127); // RFC1122
+                    return (octet[0] == 10)
+                           || (octet[0] == 172 && octet[1] >= 16 && octet[1] <= 31) // RFC1918
+                           || (octet[0] == 192 && octet[1] == 168) // RFC1918
+                           || (octet[0] == 127); // RFC1122
                 }
                 else
                 {
                     byte[] octet = address.GetAddressBytes();
                     uint word = (uint)(octet[0] << 8) + octet[1];
 
-                    return (word >= 0xfe80 && word <= 0xfebf) || // fe80::/10 :Local link.
-                           (word >= 0xfc00 && word <= 0xfdff); // fc00::/7 :Unique local address.
+                    return (word >= 0xfe80 && word <= 0xfebf) // fe80::/10 :Local link.
+                           || (word >= 0xfc00 && word <= 0xfdff); // fc00::/7 :Unique local address.
                 }
             }
 
@@ -202,7 +202,8 @@ namespace MediaBrowser.Common.Net
         /// </summary>
         /// <param name="address">IPAddress object to check.</param>
         /// <returns>True if it is a local link address.</returns>
-        /// <remarks>See https://stackoverflow.com/questions/6459928/explain-the-instance-properties-of-system-net-ipaddress
+        /// <remarks>
+        /// See https://stackoverflow.com/questions/6459928/explain-the-instance-properties-of-system-net-ipaddress
         /// it appears that the IPAddress.IsIPv6LinkLocal is out of date.
         /// </remarks>
         public static bool IsIPv6LinkLocal(IPAddress address)
@@ -237,11 +238,10 @@ namespace MediaBrowser.Common.Net
         public static IPAddress CidrToMask(byte cidr, AddressFamily family)
         {
             uint addr = 0xFFFFFFFF << (family == AddressFamily.InterNetwork ? 32 : 128 - cidr);
-            addr =
-                ((addr & 0xff000000) >> 24) |
-                ((addr & 0x00ff0000) >> 8) |
-                ((addr & 0x0000ff00) << 8) |
-                ((addr & 0x000000ff) << 24);
+            addr = ((addr & 0xff000000) >> 24)
+                   | ((addr & 0x00ff0000) >> 8)
+                   | ((addr & 0x0000ff00) << 8)
+                   | ((addr & 0x000000ff) << 24);
             return new IPAddress(addr);
         }
 
@@ -304,7 +304,7 @@ namespace MediaBrowser.Common.Net
         /// <param name="family">Type of address to remove.</param>
         public virtual void Remove(AddressFamily family)
         {
-            // This method only peforms a function in the IPHost implementation of IPObject.
+            // This method only performs a function in the IPHost implementation of IPObject.
         }
 
         /// <summary>
@@ -352,9 +352,9 @@ namespace MediaBrowser.Common.Net
         /// <returns>Equality result.</returns>
         public virtual bool Equals(IPObject? other)
         {
-            if (other != null && other is IPObject otherObj)
+            if (other != null)
             {
-                return !Address.Equals(IPAddress.None) && Address.Equals(otherObj.Address);
+                return !Address.Equals(IPAddress.None) && Address.Equals(other.Address);
             }
 
             return false;
diff --git a/MediaBrowser.Common/Net/NetworkExtensions.cs b/MediaBrowser.Common/Net/NetworkExtensions.cs
index e801de5eb..d07bba249 100644
--- a/MediaBrowser.Common/Net/NetworkExtensions.cs
+++ b/MediaBrowser.Common/Net/NetworkExtensions.cs
@@ -2,10 +2,10 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Net;
 using System.Runtime.CompilerServices;
 using System.Text;
-using NetCollection = System.Collections.ObjectModel.Collection<MediaBrowser.Common.Net.IPObject>;
 
 namespace MediaBrowser.Common.Net
 {
@@ -17,9 +17,9 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Add an address to the collection.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="ip">Item to add.</param>
-        public static void AddItem(this NetCollection source, IPAddress ip)
+        public static void AddItem(this Collection<IPObject> source, IPAddress ip)
         {
             if (!source.ContainsAddress(ip))
             {
@@ -30,9 +30,9 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Adds a network to the collection.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="item">Item to add.</param>
-        public static void AddItem(this NetCollection source, IPObject item)
+        public static void AddItem(this Collection<IPObject> source, IPObject item)
         {
             if (!source.ContainsAddress(item))
             {
@@ -43,33 +43,21 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Converts this object to a string.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <returns>Returns a string representation of this object.</returns>
-        public static string AsString(this NetCollection source)
+        public static string AsString(this Collection<IPObject> source)
         {
-            var sb = new StringBuilder();
-            string output = "[";
-            if (source.Count > 0)
-            {
-                foreach (var i in source)
-                {
-                    output += $"{i},";
-                }
-
-                output = output[0..^1];
-            }
-
-            return $"{output}]";
+            return $"[{string.Join(',', source)}]";
         }
 
         /// <summary>
         /// Returns true if the collection contains an item with the ip address,
         /// or the ip address falls within any of the collection's network ranges.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="item">The item to look for.</param>
         /// <returns>True if the collection contains the item.</returns>
-        public static bool ContainsAddress(this NetCollection source, IPAddress item)
+        public static bool ContainsAddress(this Collection<IPObject> source, IPAddress item)
         {
             if (source.Count == 0)
             {
@@ -101,10 +89,10 @@ namespace MediaBrowser.Common.Net
         /// Returns true if the collection contains an item with the ip address,
         /// or the ip address falls within any of the collection's network ranges.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="item">The item to look for.</param>
         /// <returns>True if the collection contains the item.</returns>
-        public static bool ContainsAddress(this NetCollection source, IPObject item)
+        public static bool ContainsAddress(this Collection<IPObject> source, IPObject item)
         {
             if (source.Count == 0)
             {
@@ -128,12 +116,12 @@ namespace MediaBrowser.Common.Net
         }
 
         /// <summary>
-        /// Compares two NetCollection objects. The order is ignored.
+        /// Compares two Collection{IPObject} objects. The order is ignored.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="dest">Item to compare to.</param>
         /// <returns>True if both are equal.</returns>
-        public static bool Compare(this NetCollection source, NetCollection dest)
+        public static bool Compare(this Collection<IPObject> source, Collection<IPObject> dest)
         {
             if (dest == null || source.Count != dest.Count)
             {
@@ -164,16 +152,16 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Returns a collection containing the subnets of this collection given.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
-        /// <returns>NetCollection object containing the subnets.</returns>
-        public static NetCollection AsNetworks(this NetCollection source)
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
+        /// <returns>Collection{IPObject} object containing the subnets.</returns>
+        public static Collection<IPObject> AsNetworks(this Collection<IPObject> source)
         {
             if (source == null)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            NetCollection res = new NetCollection();
+            Collection<IPObject> res = new Collection<IPObject>();
 
             foreach (IPObject i in source)
             {
@@ -184,10 +172,10 @@ namespace MediaBrowser.Common.Net
                     na.Tag = i.Tag;
                     res.AddItem(na);
                 }
-                else
+                else if (i is IPHost ipHost)
                 {
                     // Flatten out IPHost and add all its ip addresses.
-                    foreach (var addr in ((IPHost)i).GetAddresses())
+                    foreach (var addr in ipHost.GetAddresses())
                     {
                         IPNetAddress host = new IPNetAddress(addr)
                         {
@@ -205,17 +193,17 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Excludes all the items from this list that are found in excludeList.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="excludeList">Items to exclude.</param>
         /// <returns>A new collection, with the items excluded.</returns>
-        public static NetCollection Exclude(this NetCollection source, NetCollection excludeList)
+        public static Collection<IPObject> Exclude(this Collection<IPObject> source, Collection<IPObject> excludeList)
         {
             if (source.Count == 0 || excludeList == null)
             {
-                return new NetCollection(source);
+                return new Collection<IPObject>(source);
             }
 
-            NetCollection results = new NetCollection();
+            Collection<IPObject> results = new Collection<IPObject>();
 
             bool found;
             foreach (var outer in source)
@@ -243,14 +231,14 @@ namespace MediaBrowser.Common.Net
         /// <summary>
         /// Returns all items that co-exist in this object and target.
         /// </summary>
-        /// <param name="source">The <see cref="NetCollection"/>.</param>
+        /// <param name="source">The <see cref="Collection{IPObject}"/>.</param>
         /// <param name="target">Collection to compare with.</param>
         /// <returns>A collection containing all the matches.</returns>
-        public static NetCollection Union(this NetCollection source, NetCollection target)
+        public static Collection<IPObject> Union(this Collection<IPObject> source, Collection<IPObject> target)
         {
             if (source.Count == 0)
             {
-                return new NetCollection();
+                return new Collection<IPObject>();
             }
 
             if (target == null)
@@ -258,7 +246,7 @@ namespace MediaBrowser.Common.Net
                 throw new ArgumentNullException(nameof(target));
             }
 
-            NetCollection nc = new NetCollection();
+            Collection<IPObject> nc = new Collection<IPObject>();
 
             foreach (IPObject i in source)
             {