using Ryujinx.Common.Logging; using Ryujinx.HLE.HOS.Services.Sockets.Nsd; using System; using System.Collections.Generic; using System.IO; using System.IO.Enumeration; using System.Net; namespace Ryujinx.HLE.HOS.Services.Sockets.Sfdnsres.Proxy { class DnsMitmResolver { private const string HostsFilePath = "/atmosphere/hosts/default.txt"; private static DnsMitmResolver _instance; public static DnsMitmResolver Instance => _instance ??= new DnsMitmResolver(); private readonly Dictionary _mitmHostEntries = new(); public void ReloadEntries(ServiceCtx context) { string sdPath = FileSystem.VirtualFileSystem.GetSdCardPath(); string filePath = FileSystem.VirtualFileSystem.GetFullPath(sdPath, HostsFilePath); _mitmHostEntries.Clear(); if (File.Exists(filePath)) { using FileStream fileStream = File.Open(filePath, FileMode.Open, FileAccess.Read); using StreamReader reader = new(fileStream); while (!reader.EndOfStream) { string line = reader.ReadLine(); if (line == null) { break; } // Ignore comments and empty lines if (line.StartsWith('#') || line.Trim().Length == 0) { continue; } string[] entry = line.Split(new[] { ' ', '\t' }, StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries); // Hosts file example entry: // 127.0.0.1 localhost loopback // 0. Check the size of the array if (entry.Length < 2) { Logger.Warning?.PrintMsg(LogClass.ServiceBsd, $"Invalid entry in hosts file: {line}"); continue; } // 1. Parse the address if (!IPAddress.TryParse(entry[0], out IPAddress address)) { Logger.Warning?.PrintMsg(LogClass.ServiceBsd, $"Failed to parse IP address in hosts file: {entry[0]}"); continue; } // 2. Check for AMS hosts file extension: "%" for (int i = 1; i < entry.Length; i++) { entry[i] = entry[i].Replace("%", IManager.NsdSettings.Environment); } // 3. Add hostname to entry dictionary (updating duplicate entries) foreach (string hostname in entry[1..]) { _mitmHostEntries[hostname] = address; } } } } public IPHostEntry ResolveAddress(string host) { foreach (var hostEntry in _mitmHostEntries) { // Check for AMS hosts file extension: "*" // NOTE: MatchesSimpleExpression also allows "?" as a wildcard if (FileSystemName.MatchesSimpleExpression(hostEntry.Key, host)) { Logger.Info?.PrintMsg(LogClass.ServiceBsd, $"Redirecting '{host}' to: {hostEntry.Value}"); return new IPHostEntry { AddressList = new[] { hostEntry.Value }, HostName = hostEntry.Key, Aliases = Array.Empty(), }; } } // No match has been found, resolve the host using regular dns return Dns.GetHostEntry(host); } } }