diff options
Diffstat (limited to 'MediaBrowser.Common/Net/IPObject.cs')
| -rw-r--r-- | MediaBrowser.Common/Net/IPObject.cs | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/MediaBrowser.Common/Net/IPObject.cs b/MediaBrowser.Common/Net/IPObject.cs new file mode 100644 index 000000000..d18ac9893 --- /dev/null +++ b/MediaBrowser.Common/Net/IPObject.cs @@ -0,0 +1,395 @@ +#nullable enable +using System; +using System.Net; +using System.Net.Sockets; + +namespace MediaBrowser.Common.Net +{ + /// <summary> + /// Base network object class. + /// </summary> + public abstract class IPObject : IEquatable<IPObject> + { + /// <summary> + /// IPv6 Loopback address. + /// </summary> + protected static readonly byte[] Ipv6Loopback = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }; + + /// <summary> + /// IPv4 Loopback address. + /// </summary> + protected static readonly byte[] Ipv4Loopback = { 127, 0, 0, 1 }; + + /// <summary> + /// The network address of this object. + /// </summary> + private IPObject? _networkAddress; + + /// <summary> + /// Gets or sets a user defined value that is associated with this object. + /// </summary> + public int Tag { get; set; } + + /// <summary> + /// Gets or sets the object's IP address. + /// </summary> + public abstract IPAddress Address { get; set; } + + /// <summary> + /// Gets the object's network address. + /// </summary> + public IPObject NetworkAddress => _networkAddress ??= CalculateNetworkAddress(); + + /// <summary> + /// Gets or sets the object's IP address. + /// </summary> + public abstract byte PrefixLength { get; set; } + + /// <summary> + /// Gets the AddressFamily of this object. + /// </summary> + public AddressFamily AddressFamily + { + get + { + // Keep terms separate as Address performs other functions in inherited objects. + IPAddress address = Address; + return address.Equals(IPAddress.None) ? AddressFamily.Unspecified : address.AddressFamily; + } + } + + /// <summary> + /// Returns the network address of an object. + /// </summary> + /// <param name="address">IP Address to convert.</param> + /// <param name="prefixLength">Subnet prefix.</param> + /// <returns>IPAddress.</returns> + public static (IPAddress Address, byte PrefixLength) NetworkAddressOf(IPAddress address, byte prefixLength) + { + if (address == null) + { + throw new ArgumentNullException(nameof(address)); + } + + if (address.IsIPv4MappedToIPv6) + { + address = address.MapToIPv4(); + } + + if (IsLoopback(address)) + { + 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); + } + + /// <summary> + /// Tests to see if the ip address is a Loopback address. + /// </summary> + /// <param name="address">Value to test.</param> + /// <returns>True if it is.</returns> + public static bool IsLoopback(IPAddress address) + { + if (address == null) + { + throw new ArgumentNullException(nameof(address)); + } + + if (!address.Equals(IPAddress.None)) + { + if (address.IsIPv4MappedToIPv6) + { + address = address.MapToIPv4(); + } + + return address.Equals(IPAddress.Loopback) || address.Equals(IPAddress.IPv6Loopback); + } + + return false; + } + + /// <summary> + /// Tests to see if the ip address is an IP6 address. + /// </summary> + /// <param name="address">Value to test.</param> + /// <returns>True if it is.</returns> + public static bool IsIP6(IPAddress address) + { + if (address == null) + { + throw new ArgumentNullException(nameof(address)); + } + + if (address.IsIPv4MappedToIPv6) + { + address = address.MapToIPv4(); + } + + return !address.Equals(IPAddress.None) && (address.AddressFamily == AddressFamily.InterNetworkV6); + } + + /// <summary> + /// Tests to see if the address in the private address range. + /// </summary> + /// <param name="address">Object to test.</param> + /// <returns>True if it contains a private address.</returns> + public static bool IsPrivateAddressRange(IPAddress address) + { + if (address == null) + { + throw new ArgumentNullException(nameof(address)); + } + + if (!address.Equals(IPAddress.None)) + { + if (address.AddressFamily == AddressFamily.InterNetwork) + { + if (address.IsIPv4MappedToIPv6) + { + address = address.MapToIPv4(); + } + + 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 + } + 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 false; + } + + /// <summary> + /// Returns true if the IPAddress contains an IP6 Local link address. + /// </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 + /// it appears that the IPAddress.IsIPv6LinkLocal is out of date. + /// </remarks> + public static bool IsIPv6LinkLocal(IPAddress address) + { + if (address == null) + { + throw new ArgumentNullException(nameof(address)); + } + + if (address.IsIPv4MappedToIPv6) + { + address = address.MapToIPv4(); + } + + if (address.AddressFamily != AddressFamily.InterNetworkV6) + { + return false; + } + + byte[] octet = address.GetAddressBytes(); + uint word = (uint)(octet[0] << 8) + octet[1]; + + return word >= 0xfe80 && word <= 0xfebf; // fe80::/10 :Local link. + } + + /// <summary> + /// Convert a subnet mask in CIDR notation to a dotted decimal string value. IPv4 only. + /// </summary> + /// <param name="cidr">Subnet mask in CIDR notation.</param> + /// <param name="family">IPv4 or IPv6 family.</param> + /// <returns>String value of the subnet mask in dotted decimal notation.</returns> + 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); + return new IPAddress(addr); + } + + /// <summary> + /// Convert a mask to a CIDR. IPv4 only. + /// https://stackoverflow.com/questions/36954345/get-cidr-from-netmask. + /// </summary> + /// <param name="mask">Subnet mask.</param> + /// <returns>Byte CIDR representing the mask.</returns> + public static byte MaskToCidr(IPAddress mask) + { + if (mask == null) + { + throw new ArgumentNullException(nameof(mask)); + } + + byte cidrnet = 0; + if (!mask.Equals(IPAddress.Any)) + { + byte[] bytes = mask.GetAddressBytes(); + + var zeroed = false; + for (var i = 0; i < bytes.Length; i++) + { + for (int v = bytes[i]; (v & 0xFF) != 0; v <<= 1) + { + if (zeroed) + { + // Invalid netmask. + return (byte)~cidrnet; + } + + if ((v & 0x80) == 0) + { + zeroed = true; + } + else + { + cidrnet++; + } + } + } + } + + return cidrnet; + } + + /// <summary> + /// Tests to see if this object is a Loopback address. + /// </summary> + /// <returns>True if it is.</returns> + public virtual bool IsLoopback() + { + return IsLoopback(Address); + } + + /// <summary> + /// Removes all addresses of a specific type from this object. + /// </summary> + /// <param name="family">Type of address to remove.</param> + public virtual void Remove(AddressFamily family) + { + // This method only performs a function in the IPHost implementation of IPObject. + } + + /// <summary> + /// Tests to see if this object is an IPv6 address. + /// </summary> + /// <returns>True if it is.</returns> + public virtual bool IsIP6() + { + return IsIP6(Address); + } + + /// <summary> + /// Returns true if this IP address is in the RFC private address range. + /// </summary> + /// <returns>True this object has a private address.</returns> + public virtual bool IsPrivateAddressRange() + { + return IsPrivateAddressRange(Address); + } + + /// <summary> + /// Compares this to the object passed as a parameter. + /// </summary> + /// <param name="ip">Object to compare to.</param> + /// <returns>Equality result.</returns> + public virtual bool Equals(IPAddress ip) + { + if (ip != null) + { + if (ip.IsIPv4MappedToIPv6) + { + ip = ip.MapToIPv4(); + } + + return !Address.Equals(IPAddress.None) && Address.Equals(ip); + } + + return false; + } + + /// <summary> + /// Compares this to the object passed as a parameter. + /// </summary> + /// <param name="other">Object to compare to.</param> + /// <returns>Equality result.</returns> + public virtual bool Equals(IPObject? other) + { + if (other != null) + { + return !Address.Equals(IPAddress.None) && Address.Equals(other.Address); + } + + return false; + } + + /// <summary> + /// Compares the address in this object and the address in the object passed as a parameter. + /// </summary> + /// <param name="address">Object's IP address to compare to.</param> + /// <returns>Comparison result.</returns> + public abstract bool Contains(IPObject address); + + /// <summary> + /// Compares the address in this object and the address in the object passed as a parameter. + /// </summary> + /// <param name="address">Object's IP address to compare to.</param> + /// <returns>Comparison result.</returns> + public abstract bool Contains(IPAddress address); + + /// <inheritdoc/> + public override int GetHashCode() + { + return Address.GetHashCode(); + } + + /// <inheritdoc/> + public override bool Equals(object? obj) + { + return Equals(obj as IPObject); + } + + /// <summary> + /// Calculates the network address of this object. + /// </summary> + /// <returns>Returns the network address of this object.</returns> + protected abstract IPObject CalculateNetworkAddress(); + } +} |