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- using System;
- using System.Collections;
- using System.Globalization;
- using System.IO;
- using System.Net;
- using System.Net.Sockets;
- using System.Text;
- using Shadowsocks.Encryption;
- using Shadowsocks.Model;
- using Shadowsocks.Properties;
- using Shadowsocks.Util;
- using System.Threading.Tasks;
-
- namespace Shadowsocks.Controller
- {
- public class PACServer : Listener.Service
- {
- public const string PAC_FILE = "pac.txt";
- public const string USER_RULE_FILE = "user-rule.txt";
- public const string USER_ABP_FILE = "abp.txt";
-
- private string PacSecret { get; set; } = "";
-
- public string PacUrl { get; private set; } = "";
-
- FileSystemWatcher PACFileWatcher;
- FileSystemWatcher UserRuleFileWatcher;
- private Configuration _config;
-
- public event EventHandler PACFileChanged;
- public event EventHandler UserRuleFileChanged;
-
- public PACServer()
- {
- this.WatchPacFile();
- this.WatchUserRuleFile();
- }
-
- public void UpdateConfiguration(Configuration config)
- {
- this._config = config;
-
- if (config.secureLocalPac)
- {
- var rd = new byte[32];
- RNG.GetBytes(rd);
- PacSecret = $"&secret={Convert.ToBase64String(rd)}";
- }
- else
- {
- PacSecret = "";
- }
-
- PacUrl = $"http://127.0.0.1:{config.localPort}/pac?t={GetTimestamp(DateTime.Now)}{PacSecret}";
- }
-
-
- private static string GetTimestamp(DateTime value)
- {
- return value.ToString("yyyyMMddHHmmssfff");
- }
-
- public override bool Handle(byte[] firstPacket, int length, Socket socket, object state)
- {
- if (socket.ProtocolType != ProtocolType.Tcp)
- {
- return false;
- }
- try
- {
- string request = Encoding.UTF8.GetString(firstPacket, 0, length);
- string[] lines = request.Split('\r', '\n');
- bool hostMatch = false, pathMatch = false, useSocks = false;
- bool secretMatch = PacSecret.IsNullOrEmpty();
- foreach (string line in lines)
- {
- string[] kv = line.Split(new char[] { ':' }, 2);
- if (kv.Length == 2)
- {
- if (kv[0] == "Host")
- {
- if (kv[1].Trim() == ((IPEndPoint)socket.LocalEndPoint).ToString())
- {
- hostMatch = true;
- }
- }
- //else if (kv[0] == "User-Agent")
- //{
- // // we need to drop connections when changing servers
- // if (kv[1].IndexOf("Chrome") >= 0)
- // {
- // useSocks = true;
- // }
- //}
- }
- else if (kv.Length == 1)
- {
- if (line.IndexOf("pac", StringComparison.Ordinal) >= 0)
- {
- pathMatch = true;
- }
- if (!secretMatch)
- {
- if(line.IndexOf(PacSecret, StringComparison.Ordinal) >= 0)
- {
- secretMatch = true;
- }
- }
- }
- }
- if (hostMatch && pathMatch)
- {
- if (!secretMatch)
- {
- socket.Close(); // Close immediately
- }
- else
- {
- SendResponse(socket, useSocks);
- }
- return true;
- }
- return false;
- }
- catch (ArgumentException)
- {
- return false;
- }
- }
-
- public string TouchPACFile()
- {
- if (File.Exists(PAC_FILE))
- {
- return PAC_FILE;
- }
- else
- {
- FileManager.UncompressFile(PAC_FILE, Resources.proxy_pac_txt);
- return PAC_FILE;
- }
- }
-
- internal string TouchUserRuleFile()
- {
- if (File.Exists(USER_RULE_FILE))
- {
- return USER_RULE_FILE;
- }
- else
- {
- File.WriteAllText(USER_RULE_FILE, Resources.user_rule);
- return USER_RULE_FILE;
- }
- }
-
- private string GetPACContent()
- {
- if (File.Exists(PAC_FILE))
- {
- return File.ReadAllText(PAC_FILE, Encoding.UTF8);
- }
- else
- {
- return Utils.UnGzip(Resources.proxy_pac_txt);
- }
- }
-
- public void SendResponse(Socket socket, bool useSocks)
- {
- try
- {
- IPEndPoint localEndPoint = (IPEndPoint)socket.LocalEndPoint;
-
- string proxy = GetPACAddress(localEndPoint, useSocks);
-
- string pacContent = GetPACContent().Replace("__PROXY__", proxy);
-
- string responseHead = String.Format(@"HTTP/1.1 200 OK
- Server: Shadowsocks
- Content-Type: application/x-ns-proxy-autoconfig
- Content-Length: {0}
- Connection: Close
-
- ", Encoding.UTF8.GetBytes(pacContent).Length);
- byte[] response = Encoding.UTF8.GetBytes(responseHead + pacContent);
- socket.BeginSend(response, 0, response.Length, 0, new AsyncCallback(SendCallback), socket);
- Utils.ReleaseMemory(true);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- socket.Close();
- }
- }
-
- private void SendCallback(IAsyncResult ar)
- {
- Socket conn = (Socket)ar.AsyncState;
- try
- {
- conn.Shutdown(SocketShutdown.Send);
- }
- catch
- { }
- }
-
- private void WatchPacFile()
- {
- PACFileWatcher?.Dispose();
- PACFileWatcher = new FileSystemWatcher(Directory.GetCurrentDirectory());
- PACFileWatcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
- PACFileWatcher.Filter = PAC_FILE;
- PACFileWatcher.Changed += PACFileWatcher_Changed;
- PACFileWatcher.Created += PACFileWatcher_Changed;
- PACFileWatcher.Deleted += PACFileWatcher_Changed;
- PACFileWatcher.Renamed += PACFileWatcher_Changed;
- PACFileWatcher.EnableRaisingEvents = true;
- }
-
- private void WatchUserRuleFile()
- {
- UserRuleFileWatcher?.Dispose();
- UserRuleFileWatcher = new FileSystemWatcher(Directory.GetCurrentDirectory());
- UserRuleFileWatcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
- UserRuleFileWatcher.Filter = USER_RULE_FILE;
- UserRuleFileWatcher.Changed += UserRuleFileWatcher_Changed;
- UserRuleFileWatcher.Created += UserRuleFileWatcher_Changed;
- UserRuleFileWatcher.Deleted += UserRuleFileWatcher_Changed;
- UserRuleFileWatcher.Renamed += UserRuleFileWatcher_Changed;
- UserRuleFileWatcher.EnableRaisingEvents = true;
- }
-
- #region FileSystemWatcher.OnChanged()
- // FileSystemWatcher Changed event is raised twice
- // http://stackoverflow.com/questions/1764809/filesystemwatcher-changed-event-is-raised-twice
- // Add a short delay to avoid raise event twice in a short period
- private void PACFileWatcher_Changed(object sender, FileSystemEventArgs e)
- {
- if (PACFileChanged != null)
- {
- Logging.Info($"Detected: PAC file '{e.Name}' was {e.ChangeType.ToString().ToLower()}.");
- Task.Factory.StartNew(() =>
- {
- ((FileSystemWatcher)sender).EnableRaisingEvents = false;
- System.Threading.Thread.Sleep(10);
- PACFileChanged(this, new EventArgs());
- ((FileSystemWatcher)sender).EnableRaisingEvents = true;
- });
- }
- }
-
- private void UserRuleFileWatcher_Changed(object sender, FileSystemEventArgs e)
- {
- if (UserRuleFileChanged != null)
- {
- Logging.Info($"Detected: User Rule file '{e.Name}' was {e.ChangeType.ToString().ToLower()}.");
- Task.Factory.StartNew(()=>
- {
- ((FileSystemWatcher)sender).EnableRaisingEvents = false;
- System.Threading.Thread.Sleep(10);
- UserRuleFileChanged(this, new EventArgs());
- ((FileSystemWatcher)sender).EnableRaisingEvents = true;
- });
- }
- }
- #endregion
-
- private string GetPACAddress(IPEndPoint localEndPoint, bool useSocks)
- {
- return $"{(useSocks ? "SOCKS5" : "PROXY")} {localEndPoint.Address}:{_config.localPort};";
- }
- }
- }
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