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Diffstat (limited to 'Jellyfin.Networking/Extensions/NetworkExtensions.cs')
| -rw-r--r-- | Jellyfin.Networking/Extensions/NetworkExtensions.cs | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/Jellyfin.Networking/Extensions/NetworkExtensions.cs b/Jellyfin.Networking/Extensions/NetworkExtensions.cs new file mode 100644 index 000000000..a1e1140f1 --- /dev/null +++ b/Jellyfin.Networking/Extensions/NetworkExtensions.cs @@ -0,0 +1,346 @@ +using System; +using System.Collections.Generic; +using System.Diagnostics.CodeAnalysis; +using System.Net; +using System.Net.Sockets; +using System.Text.RegularExpressions; +using Jellyfin.Extensions; +using Jellyfin.Networking.Constants; +using Microsoft.AspNetCore.HttpOverrides; + +namespace Jellyfin.Networking.Extensions; + +/// <summary> +/// Defines the <see cref="NetworkExtensions" />. +/// </summary> +public static partial class NetworkExtensions +{ + // Use regular expression as CheckHostName isn't RFC5892 compliant. + // Modified from gSkinner's expression at https://stackoverflow.com/questions/11809631/fully-qualified-domain-name-validation + [GeneratedRegex(@"(?im)^(?!:\/\/)(?=.{1,255}$)((.{1,63}\.){0,127}(?![0-9]*$)[a-z0-9-]+\.?)(:(\d){1,5}){0,1}$", RegexOptions.IgnoreCase, "en-US")] + private static partial Regex FqdnGeneratedRegex(); + + /// <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+ /// it appears that the IPAddress.IsIPv6LinkLocal is out of date.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) + { + ArgumentNullException.ThrowIfNull(address); + + if (address.IsIPv4MappedToIPv6) + { + address = address.MapToIPv4(); + } + + if (address.AddressFamily != AddressFamily.InterNetworkV6) + { + return false; + } + + // GetAddressBytes + Span<byte> octet = stackalloc byte[16]; + address.TryWriteBytes(octet, out _); + 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 ? Network.MinimumIPv4PrefixSize : Network.MinimumIPv6PrefixSize) - cidr); + addr = ((addr & 0xff000000) >> 24) + | ((addr & 0x00ff0000) >> 8) + | ((addr & 0x0000ff00) << 8) + | ((addr & 0x000000ff) << 24); + return new IPAddress(addr); + } + + /// <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(int cidr, AddressFamily family) + { + uint addr = 0xFFFFFFFF << ((family == AddressFamily.InterNetwork ? Network.MinimumIPv4PrefixSize : Network.MinimumIPv6PrefixSize) - cidr); + addr = ((addr & 0xff000000) >> 24) + | ((addr & 0x00ff0000) >> 8) + | ((addr & 0x0000ff00) << 8) + | ((addr & 0x000000ff) << 24); + return new IPAddress(addr); + } + + /// <summary> + /// Convert a subnet 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) + { + ArgumentNullException.ThrowIfNull(mask); + + byte cidrnet = 0; + if (mask.Equals(IPAddress.Any)) + { + return cidrnet; + } + + // GetAddressBytes + Span<byte> bytes = stackalloc byte[mask.AddressFamily == AddressFamily.InterNetwork ? Network.IPv4MaskBytes : Network.IPv6MaskBytes]; + if (!mask.TryWriteBytes(bytes, out var bytesWritten)) + { + Console.WriteLine("Unable to write address bytes, only ${bytesWritten} bytes written."); + } + + 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> + /// Converts an IPAddress into a string. + /// IPv6 addresses are returned in [ ], with their scope removed. + /// </summary> + /// <param name="address">Address to convert.</param> + /// <returns>URI safe conversion of the address.</returns> + public static string FormatIPString(IPAddress? address) + { + if (address is null) + { + return string.Empty; + } + + var str = address.ToString(); + if (address.AddressFamily == AddressFamily.InterNetworkV6) + { + int i = str.IndexOf('%', StringComparison.Ordinal); + if (i != -1) + { + str = str.Substring(0, i); + } + + return $"[{str}]"; + } + + return str; + } + + /// <summary> + /// Try parsing an array of strings into <see cref="IPNetwork"/> objects, respecting exclusions. + /// Elements without a subnet mask will be represented as <see cref="IPNetwork"/> with a single IP. + /// </summary> + /// <param name="values">Input string array to be parsed.</param> + /// <param name="result">Collection of <see cref="IPNetwork"/>.</param> + /// <param name="negated">Boolean signaling if negated or not negated values should be parsed.</param> + /// <returns><c>True</c> if parsing was successful.</returns> + public static bool TryParseToSubnets(string[] values, [NotNullWhen(true)] out IReadOnlyList<IPNetwork>? result, bool negated = false) + { + if (values is null || values.Length == 0) + { + result = null; + return false; + } + + var tmpResult = new List<IPNetwork>(); + for (int a = 0; a < values.Length; a++) + { + if (TryParseToSubnet(values[a], out var innerResult, negated)) + { + tmpResult.Add(innerResult); + } + } + + result = tmpResult; + return tmpResult.Count > 0; + } + + /// <summary> + /// Try parsing a string into an <see cref="IPNetwork"/>, respecting exclusions. + /// Inputs without a subnet mask will be represented as <see cref="IPNetwork"/> with a single IP. + /// </summary> + /// <param name="value">Input string to be parsed.</param> + /// <param name="result">An <see cref="IPNetwork"/>.</param> + /// <param name="negated">Boolean signaling if negated or not negated values should be parsed.</param> + /// <returns><c>True</c> if parsing was successful.</returns> + public static bool TryParseToSubnet(ReadOnlySpan<char> value, [NotNullWhen(true)] out IPNetwork? result, bool negated = false) + { + var splitString = value.Trim().Split('/'); + if (splitString.MoveNext()) + { + var ipBlock = splitString.Current; + var address = IPAddress.None; + if (negated && ipBlock.StartsWith("!") && IPAddress.TryParse(ipBlock[1..], out var tmpAddress)) + { + address = tmpAddress; + } + else if (!negated && IPAddress.TryParse(ipBlock, out tmpAddress)) + { + address = tmpAddress; + } + + if (address != IPAddress.None) + { + if (splitString.MoveNext()) + { + var subnetBlock = splitString.Current; + if (int.TryParse(subnetBlock, out var netmask)) + { + result = new IPNetwork(address, netmask); + return true; + } + else if (IPAddress.TryParse(subnetBlock, out var netmaskAddress)) + { + result = new IPNetwork(address, NetworkExtensions.MaskToCidr(netmaskAddress)); + return true; + } + } + else if (address.AddressFamily == AddressFamily.InterNetwork) + { + result = address.Equals(IPAddress.Any) ? Network.IPv4Any : new IPNetwork(address, Network.MinimumIPv4PrefixSize); + return true; + } + else if (address.AddressFamily == AddressFamily.InterNetworkV6) + { + result = address.Equals(IPAddress.IPv6Any) ? Network.IPv6Any : new IPNetwork(address, Network.MinimumIPv6PrefixSize); + return true; + } + } + } + + result = null; + return false; + } + + /// <summary> + /// Attempts to parse a host span. + /// </summary> + /// <param name="host">Host name to parse.</param> + /// <param name="addresses">Object representing the span, if it has successfully been parsed.</param> + /// <param name="isIPv4Enabled"><c>true</c> if IPv4 is enabled.</param> + /// <param name="isIPv6Enabled"><c>true</c> if IPv6 is enabled.</param> + /// <returns><c>true</c> if the parsing is successful, <c>false</c> if not.</returns> + public static bool TryParseHost(ReadOnlySpan<char> host, [NotNullWhen(true)] out IPAddress[]? addresses, bool isIPv4Enabled = true, bool isIPv6Enabled = false) + { + host = host.Trim(); + if (host.IsEmpty) + { + addresses = null; + return false; + } + + // See if it's an IPv6 with port address e.g. [::1] or [::1]:120. + if (host[0] == '[') + { + int i = host.IndexOf(']'); + if (i != -1) + { + return TryParseHost(host[1..(i - 1)], out addresses); + } + + addresses = Array.Empty<IPAddress>(); + return false; + } + + var hosts = new List<string>(); + foreach (var splitSpan in host.Split(':')) + { + hosts.Add(splitSpan.ToString()); + } + + if (hosts.Count <= 2) + { + var firstPart = hosts[0]; + + // Is hostname or hostname:port + if (FqdnGeneratedRegex().IsMatch(firstPart)) + { + try + { + // .NET automatically filters only supported returned addresses based on OS support. + addresses = Dns.GetHostAddresses(firstPart); + return true; + } + catch (SocketException) + { + // Ignore socket errors, as the result value will just be an empty array. + } + } + + // Is an IPv4 or IPv4:port + if (IPAddress.TryParse(firstPart.AsSpan().LeftPart('/'), out var address)) + { + if (((address.AddressFamily == AddressFamily.InterNetwork) && (!isIPv4Enabled && isIPv6Enabled)) + || ((address.AddressFamily == AddressFamily.InterNetworkV6) && (isIPv4Enabled && !isIPv6Enabled))) + { + addresses = Array.Empty<IPAddress>(); + return false; + } + + addresses = new[] { address }; + + // Host name is an IPv4 address, so fake resolve. + return true; + } + } + else if (hosts.Count > 0 && hosts.Count <= 9) // 8 octets + port + { + if (IPAddress.TryParse(host.LeftPart('/'), out var address)) + { + addresses = new[] { address }; + return true; + } + } + + addresses = Array.Empty<IPAddress>(); + return false; + } + + /// <summary> + /// Gets the broadcast address for a <see cref="IPNetwork"/>. + /// </summary> + /// <param name="network">The <see cref="IPNetwork"/>.</param> + /// <returns>The broadcast address.</returns> + public static IPAddress GetBroadcastAddress(IPNetwork network) + { + var addressBytes = network.Prefix.GetAddressBytes(); + uint ipAddress = BitConverter.ToUInt32(addressBytes, 0); + uint ipMaskV4 = BitConverter.ToUInt32(CidrToMask(network.PrefixLength, AddressFamily.InterNetwork).GetAddressBytes(), 0); + uint broadCastIPAddress = ipAddress | ~ipMaskV4; + + return new IPAddress(BitConverter.GetBytes(broadCastIPAddress)); + } +} |