Ryujinx/Ryujinx.HLE/HOS/Services/Sockets/Sfdnsres/Proxy/DnsMitmResolver.cs
TSRBerry df758eddd1
Bsd: Add support for dns_mitm (#4102)
* bsd: Add dns_mitm from Atmosphère

related AMS files:
- https://github.com/Atmosphere-NX/Atmosphere/blob/master/stratosphere/ams_mitm/source/dns_mitm/dnsmitm_resolver_impl.cpp
- https://github.com/Atmosphere-NX/Atmosphere/blob/master/stratosphere/ams_mitm/source/dns_mitm/dnsmitm_host_redirection.cpp

* Remove debug logging and adjust redirect message

* Improve formatting

Co-authored-by: Ac_K <Acoustik666@gmail.com>

* Replace Initialize with instance property

* bsd: dns_mitm - Ignore empty lines

* bsd: Mark _mitmHostEntries as readonly

* bsd: Initialize Aliases when returning IpHostEntry

Fixes NullReferenceException

Co-authored-by: Ac_K <Acoustik666@gmail.com>
2022-12-12 18:04:08 +01:00

106 lines
No EOL
3.8 KiB
C#

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<string, IPAddress> _mitmHostEntries = new();
public void ReloadEntries(ServiceCtx context)
{
string sdPath = context.Device.Configuration.VirtualFileSystem.GetSdCardPath();
string filePath = context.Device.Configuration.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<string>()
};
}
}
// No match has been found, resolve the host using regular dns
return Dns.GetHostEntry(host);
}
}
}