diff options
Diffstat (limited to 'MediaBrowser.Common/Net/IPObject.cs')
| -rw-r--r-- | MediaBrowser.Common/Net/IPObject.cs | 56 |
1 files changed, 28 insertions, 28 deletions
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; |