KancolleSniffer/HttpProxy.cs

   1 // Copyright (c) 2015 Kazuhiro Fujieda <fujieda@users.osdn.me>\r
   2 //\r
   3 // Licensed under the Apache License, Version 2.0 (the "License");\r
   4 // you may not use this file except in compliance with the License.\r
   5 // You may obtain a copy of the License at\r
   6 //\r
   7 //    http://www.apache.org/licenses/LICENSE-2.0\r
   8 //\r
   9 // Unless required by applicable law or agreed to in writing, software\r
  10 // distributed under the License is distributed on an "AS IS" BASIS,\r
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  12 // See the License for the specific language governing permissions and\r
  13 // limitations under the License.\r
  14 \r
  15 using System;\r
  16 using System.Globalization;\r
  17 using System.IO;\r
  18 using System.IO.Compression;\r
  19 using System.Net;\r
  20 using System.Net.Sockets;\r
  21 using System.Text;\r
  22 using System.Text.RegularExpressions;\r
  23 using System.Threading.Tasks;\r
  24 \r
  25 namespace KancolleSniffer\r
  26 {\r
  27     public class HttpProxy\r
  28     {\r
  29         private static HttpProxy _httpProxy;\r
  30         public static int LocalPort { get; set; }\r
  31         public static string UpstreamProxyHost { get; set; }\r
  32         public static int UpstreamProxyPort { get; set; }\r
  33         public static bool IsEnableUpstreamProxy { get; set; }\r
  34         public static bool IsInListening { get; private set; }\r
  35         public static event Action<Session> AfterSessionComplete;\r
  36 \r
  37         private TcpListener _listener;\r
  38 \r
  39         public static void Startup(int port, bool dummy0, bool dummy1)\r
  40         {\r
  41             LocalPort = port;\r
  42             _httpProxy = new HttpProxy();\r
  43             _httpProxy.Start();\r
  44         }\r
  45 \r
  46         public void Start()\r
  47         {\r
  48             _listener = new TcpListener(IPAddress.Loopback, LocalPort);\r
  49             _listener.Start();\r
  50             LocalPort = ((IPEndPoint)_listener.LocalEndpoint).Port;\r
  51             IsInListening = true;\r
  52             Task.Run(() => AcceptClient());\r
  53         }\r
  54 \r
  55         public static void Shutdown()\r
  56         {\r
  57             _httpProxy?.Stop();\r
  58         }\r
  59 \r
  60         public void Stop()\r
  61         {\r
  62             IsInListening = false;\r
  63             _listener.Server.Close();\r
  64             _listener.Stop();\r
  65         }\r
  66 \r
  67         public void AcceptClient()\r
  68         {\r
  69             try\r
  70             {\r
  71                 while (true)\r
  72                 {\r
  73                     var client = _listener.AcceptSocket();\r
  74                     Task.Run(() => new HttpClient(client).ProcessRequest());\r
  75                 }\r
  76             }\r
  77             catch (SocketException)\r
  78             {\r
  79             }\r
  80             finally\r
  81             {\r
  82                 Stop();\r
  83             }\r
  84         }\r
  85 \r
  86         private class HttpClient\r
  87         {\r
  88             private readonly Socket _client;\r
  89             private Socket _server;\r
  90             private readonly Session _session;\r
  91             private readonly HttpStream _clientStream;\r
  92             private HttpStream _serverStream;\r
  93 \r
  94             public HttpClient(Socket client)\r
  95             {\r
  96                 _client = client;\r
  97                 _clientStream = new HttpStream(client);\r
  98                 _session = new Session();\r
  99             }\r
 100 \r
 101             public void ProcessRequest()\r
 102             {\r
 103                 try\r
 104                 {\r
 105                     ReceiveRequest();\r
 106                     if (_session.Request.Method == null)\r
 107                         return;\r
 108                     if (_session.Request.Method == "CONNECT")\r
 109                     {\r
 110                         HandleConnect();\r
 111                         return;\r
 112                     }\r
 113                     if (_session.Request.Host.StartsWith("localhost") || _session.Request.Host.StartsWith("127.0.0.1"))\r
 114                     {\r
 115                         LogServer.Process(_client, _session.Request.RequestLine);\r
 116                         return;\r
 117                     }\r
 118                     SendRequest();\r
 119                     ReceiveRequestBody();\r
 120                     SendRequestBody();\r
 121                     ReceiveResponse();\r
 122                     if (_session.Response.StatusCode == null)\r
 123                         return;\r
 124                     SendResponse();\r
 125                     Close();\r
 126                     AfterSessionComplete?.Invoke(_session);\r
 127                 }\r
 128 #if DEBUG\r
 129                 catch (Exception e)\r
 130                 {\r
 131                     File.AppendAllText("debug.log", $"[{DateTime.Now:g}] " + e + "\r\n");\r
 132                 }\r
 133 #else // ReSharper disable once EmptyGeneralCatchClause\r
 134                 catch\r
 135                 {\r
 136                 }\r
 137 #endif\r
 138                 finally\r
 139                 {\r
 140                     Close();\r
 141                 }\r
 142             }\r
 143 \r
 144             private void ReceiveRequest()\r
 145             {\r
 146                 var requestLine = _clientStream.ReadLine();\r
 147                 if (requestLine == "")\r
 148                     return;\r
 149                 _session.Request.RequestLine = requestLine;\r
 150                 _session.Request.Headers = _clientStream.ReadHeaders();\r
 151             }\r
 152 \r
 153             private void ReceiveRequestBody()\r
 154             {\r
 155                 if (_session.Request.ContentLength != -1 || _session.Request.TransferEncoding != null)\r
 156                     _session.Request.ReadBody(_clientStream);\r
 157             }\r
 158 \r
 159             private void SendRequest()\r
 160             {\r
 161                 _server = ConnectServer();\r
 162                 _serverStream = new HttpStream(_server).\r
 163                     WriteLines(_session.Request.RequestLine + _session.Request.ModifiedHeaders);\r
 164             }\r
 165 \r
 166             private void SendRequestBody()\r
 167             {\r
 168                 _serverStream.Write(_session.Request.Body);\r
 169             }\r
 170 \r
 171             private void ReceiveResponse()\r
 172             {\r
 173                 var statusLine = _serverStream.ReadLine();\r
 174                 if (statusLine == "")\r
 175                     return;\r
 176                 _session.Response.StatusLine = statusLine;\r
 177                 _session.Response.Headers = _serverStream.ReadHeaders();\r
 178                 if (HasBody)\r
 179                     _session.Response.ReadBody(_serverStream);\r
 180             }\r
 181 \r
 182             private bool HasBody\r
 183             {\r
 184                 get\r
 185                 {\r
 186                     var code = _session.Response.StatusCode;\r
 187                     return (!(_session.Request.Method == "HEAD" ||\r
 188                               code.StartsWith("1") || code == "204" || code == "304"));\r
 189                 }\r
 190             }\r
 191 \r
 192             private void SendResponse()\r
 193             {\r
 194                 _clientStream.WriteLines(_session.Response.StatusLine + _session.Response.ModifiedHeaders)\r
 195                     .Write(_session.Response.Body);\r
 196             }\r
 197 \r
 198             private void HandleConnect()\r
 199             {\r
 200                 var host = "";\r
 201                 var port = 443;\r
 202                 if (!ParseAuthority(_session.Request.PathAndQuery, ref host, ref port))\r
 203                     return;\r
 204                 _server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);\r
 205                 _server.Connect(host, port);\r
 206                 _clientStream.WriteLines("HTTP/1.0 200 Connection established\r\n\r\n");\r
 207                 Task[] tasks =\r
 208                 {\r
 209                     Task.Run(() => { TunnnelSockets(_client, _server); }),\r
 210                     Task.Run(() => { TunnnelSockets(_server, _client); })\r
 211                 };\r
 212                 Task.WaitAll(tasks);\r
 213             }\r
 214 \r
 215             private void TunnnelSockets(Socket from, Socket to)\r
 216             {\r
 217                 try\r
 218                 {\r
 219                     var buf = new byte[8192];\r
 220                     while (true)\r
 221                     {\r
 222                         var n = from.Receive(buf);\r
 223                         if (n == 0)\r
 224                             break;\r
 225                         var sent = to.Send(buf, n, SocketFlags.None);\r
 226                         if (sent < n)\r
 227                             break;\r
 228                     }\r
 229                     to.Shutdown(SocketShutdown.Send);\r
 230                 }\r
 231                 catch (SocketException)\r
 232                 {\r
 233                 }\r
 234             }\r
 235 \r
 236             private static readonly Regex HostAndPortRegex =\r
 237                 new Regex("http://([^:/]+)(?::(\\d+))?/", RegexOptions.Compiled);\r
 238 \r
 239             private Socket ConnectServer()\r
 240             {\r
 241                 string host = null;\r
 242                 var port = 80;\r
 243                 if (IsEnableUpstreamProxy)\r
 244                 {\r
 245                     host = UpstreamProxyHost;\r
 246                     port = UpstreamProxyPort;\r
 247                     goto connect;\r
 248                 }\r
 249                 var m = HostAndPortRegex.Match(_session.Request.RequestLine);\r
 250                 if (m.Success)\r
 251                 {\r
 252                     host = m.Groups[1].Value;\r
 253                     if (m.Groups[2].Success)\r
 254                         port = int.Parse(m.Groups[2].Value);\r
 255                     _session.Request.RequestLine = _session.Request.RequestLine.Remove(m.Index, m.Length - 1);\r
 256                 }\r
 257                 if (host == null && !ParseAuthority(_session.Request.Host, ref host, ref port))\r
 258                     throw new HttpProxyAbort("Can't find destination host");\r
 259                 connect:\r
 260                 var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);\r
 261                 socket.Connect(host, port);\r
 262                 return socket;\r
 263             }\r
 264 \r
 265             private static readonly Regex AuthorityRegex = new Regex("([^:]+)(?::(\\d+))?");\r
 266 \r
 267             private bool ParseAuthority(string authority, ref string host, ref int port)\r
 268             {\r
 269                 if (string.IsNullOrEmpty(authority))\r
 270                     return false;\r
 271                 var m = AuthorityRegex.Match(authority);\r
 272                 if (!m.Success)\r
 273                     return false;\r
 274                 host = m.Groups[1].Value;\r
 275                 if (m.Groups[2].Success)\r
 276                     port = int.Parse(m.Groups[2].Value);\r
 277                 return true;\r
 278             }\r
 279 \r
 280             private void Close()\r
 281             {\r
 282                 _serverStream?.Close();\r
 283                 _clientStream?.Close();\r
 284                 _server?.Close();\r
 285                 _client.Close();\r
 286             }\r
 287         }\r
 288 \r
 289         public class Session\r
 290         {\r
 291             public Request Request { get; set; } = new Request();\r
 292             public Response Response { get; set; } = new Response();\r
 293         }\r
 294 \r
 295         public class Message\r
 296         {\r
 297             private string _headers;\r
 298             public byte[] Body { get; set; }\r
 299 \r
 300             private static readonly Regex CharsetRegx = new Regex("charset=([\\w-]+)",\r
 301                 RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);\r
 302 \r
 303             public int ContentLength { get; set; } = -1;\r
 304             public string TransferEncoding { get; set; }\r
 305             public string ContentType { get; set; }\r
 306             public string ContentEncoding { get; set; }\r
 307             public string Host { get; set; }\r
 308 \r
 309             public string Headers\r
 310             {\r
 311                 get => _headers;\r
 312                 set\r
 313                 {\r
 314                     _headers = value;\r
 315                     SetHeaders(_headers);\r
 316                 }\r
 317             }\r
 318 \r
 319             public virtual string ModifiedHeaders => SetConnectionClose(Headers);\r
 320 \r
 321             private string SetConnectionClose(string headers)\r
 322             {\r
 323                 return InsertHeader(RemoveHeaders(headers,\r
 324                     new[] {"connection", "keep-alive", "proxy-connection"}), "Connection: close\r\n");\r
 325             }\r
 326 \r
 327             protected string RemoveHeaders(string headers, string[] fields)\r
 328             {\r
 329                 foreach (var f in fields)\r
 330                 {\r
 331                     var m = MatchField(f, headers);\r
 332                     if (!m.Success)\r
 333                         continue;\r
 334                     headers = headers.Remove(m.Index, m.Length);\r
 335                 }\r
 336                 return headers;\r
 337             }\r
 338 \r
 339             protected string InsertHeader(string headers, string header)\r
 340             {\r
 341                 return headers.Insert(headers.Length - 2, header);\r
 342             }\r
 343 \r
 344             protected virtual void SetHeaders(string headers)\r
 345             {\r
 346                 var s = GetField("content-length");\r
 347                 if (s != null)\r
 348                 {\r
 349                     ContentLength = int.TryParse(s, out var len) ? len : -1;\r
 350                 }\r
 351                 TransferEncoding = GetField("transfer-encoding")?.ToLower(CultureInfo.InvariantCulture);\r
 352                 ContentType = GetField("content-type");\r
 353                 ContentEncoding = GetField("content-encoding");\r
 354                 Host = GetField("host");\r
 355             }\r
 356 \r
 357             protected Match MatchField(string name, string headers)\r
 358             {\r
 359                 var regex = new Regex("^" + name + ":\\s*([^\r]+)\r\n",\r
 360                     RegexOptions.CultureInvariant | RegexOptions.IgnoreCase | RegexOptions.Multiline);\r
 361                 return regex.Match(headers);\r
 362             }\r
 363 \r
 364             protected string GetField(string name)\r
 365             {\r
 366                 var m = MatchField(name, Headers);\r
 367                 return m.Success ? m.Groups[1].Value : null;\r
 368             }\r
 369 \r
 370             public string BodyAsString\r
 371             {\r
 372                 get\r
 373                 {\r
 374                     if (Body == null)\r
 375                         return "";\r
 376                     var m = CharsetRegx.Match(ContentType ?? "");\r
 377                     var encoding = Encoding.ASCII;\r
 378                     if (m.Success)\r
 379                     {\r
 380                         var name = m.Groups[1].Value;\r
 381                         if (name == "utf8")\r
 382                             name = "UTF-8";\r
 383                         encoding = Encoding.GetEncoding(name);\r
 384                     }\r
 385                     return encoding.GetString(Body);\r
 386                 }\r
 387             }\r
 388 \r
 389             public void ReadBody(HttpStream stream)\r
 390             {\r
 391                 if (TransferEncoding != null && TransferEncoding.Contains("chunked"))\r
 392                 {\r
 393                     Body = stream.ReadChunked();\r
 394                 }\r
 395                 else if (ContentLength == 0)\r
 396                 {\r
 397                 }\r
 398                 else if (ContentLength > 0)\r
 399                 {\r
 400                     var buf = new byte[ContentLength];\r
 401                     stream.Read(buf, 0, ContentLength);\r
 402                     Body = buf;\r
 403                 }\r
 404                 else\r
 405                 {\r
 406                     Body = stream.ReadToEnd();\r
 407                 }\r
 408                 if (ContentEncoding == null)\r
 409                     return;\r
 410                 var dc = new MemoryStream();\r
 411                 try\r
 412                 {\r
 413                     if (ContentEncoding == "gzip")\r
 414                         new GZipStream(new MemoryStream(Body), CompressionMode.Decompress).CopyTo(dc);\r
 415                     else if (ContentEncoding == "deflate")\r
 416                         new DeflateStream(new MemoryStream(Body), CompressionMode.Decompress).CopyTo(dc);\r
 417                 }\r
 418                 catch (Exception ex)\r
 419                 {\r
 420                     throw new HttpProxyAbort($"Fail to decode {ContentEncoding}: " + ex.Message);\r
 421                 }\r
 422                 Body = dc.ToArray();\r
 423             }\r
 424         }\r
 425 \r
 426         public class Request : Message\r
 427         {\r
 428             private string _requestLine;\r
 429 \r
 430             public string RequestLine\r
 431             {\r
 432                 get => _requestLine;\r
 433                 set\r
 434                 {\r
 435                     _requestLine = value;\r
 436                     var f = _requestLine.Split(' ');\r
 437                     if (f.Length < 3)\r
 438                         throw new HttpProxyAbort("Invalid request line");\r
 439                     Method = f[0];\r
 440                     PathAndQuery = f.Length < 2 ? "" : f[1];\r
 441                 }\r
 442             }\r
 443 \r
 444             public string Method { get; private set; }\r
 445             public string PathAndQuery { get; private set; }\r
 446         }\r
 447 \r
 448         public class Response : Message\r
 449         {\r
 450             private string _statusLine;\r
 451 \r
 452             public override string ModifiedHeaders =>\r
 453                 InsertContentLength(RemoveHeaders(base.ModifiedHeaders,\r
 454                     new[] {"transfer-encoding", "content-encoding", "content-length"}));\r
 455 \r
 456             private string InsertContentLength(string headers)\r
 457             {\r
 458                 return Body == null ? headers : InsertHeader(headers, $"Content-Length: {Body.Length}\r\n");\r
 459             }\r
 460 \r
 461             public string StatusLine\r
 462             {\r
 463                 get => _statusLine;\r
 464                 set\r
 465                 {\r
 466                     _statusLine = value;\r
 467                     var f = _statusLine.Split(' ');\r
 468                     if (f.Length < 3)\r
 469                         throw new HttpProxyAbort("Invalid status line");\r
 470                     StatusCode = _statusLine.Split(' ')[1];\r
 471                 }\r
 472             }\r
 473 \r
 474             public string StatusCode { get; private set; }\r
 475         }\r
 476 \r
 477         private class HttpProxyAbort : Exception\r
 478         {\r
 479             public HttpProxyAbort(string message) : base(message)\r
 480             {\r
 481             }\r
 482         }\r
 483 \r
 484         public class HttpStream\r
 485         {\r
 486             private readonly Socket _socket;\r
 487             private readonly byte[] _buffer = new byte[4096];\r
 488             private int _available;\r
 489             private int _position;\r
 490 \r
 491             public HttpStream(Socket socket)\r
 492             {\r
 493                 _socket = socket;\r
 494                 socket.NoDelay = true;\r
 495             }\r
 496 \r
 497             public string ReadLine()\r
 498             {\r
 499                 var sb = new StringBuilder();\r
 500                 int ch;\r
 501                 while ((ch = ReadByte()) != -1)\r
 502                 {\r
 503                     sb.Append((char)ch);\r
 504                     if (ch == '\n')\r
 505                         break;\r
 506                 }\r
 507                 return sb.ToString();\r
 508             }\r
 509 \r
 510             private int ReadByte()\r
 511             {\r
 512                 if (_position < _available)\r
 513                     return _buffer[_position++];\r
 514                 _available = _socket.Receive(_buffer, 0, _buffer.Length, SocketFlags.None);\r
 515                 _position = 0;\r
 516                 return _available == 0 ? -1 : _buffer[_position++];\r
 517             }\r
 518 \r
 519             public HttpStream WriteLines(string s)\r
 520             {\r
 521                 var buf = Encoding.ASCII.GetBytes(s);\r
 522                 Write(buf, 0, buf.Length);\r
 523                 return this;\r
 524             }\r
 525 \r
 526             public string ReadHeaders()\r
 527             {\r
 528                 var sb = new StringBuilder();\r
 529                 string line;\r
 530                 do\r
 531                 {\r
 532                     line = ReadLine();\r
 533                     sb.Append(line);\r
 534                 } while (line != "\r\n");\r
 535                 return sb.ToString();\r
 536             }\r
 537 \r
 538             public byte[] ReadChunked()\r
 539             {\r
 540                 var buf = new MemoryStream();\r
 541                 while (true)\r
 542                 {\r
 543                     var size = ReadLine();\r
 544                     if (size.Length < 3)\r
 545                         break;\r
 546                     var ext = size.IndexOf(';');\r
 547                     size = ext == -1 ? size.Substring(0, size.Length - 2) : size.Substring(0, ext);\r
 548                     if (!int.TryParse(size, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var val))\r
 549                         throw new HttpProxyAbort("Can't parse chunk size: " + size);\r
 550                     if (val == 0)\r
 551                         break;\r
 552                     var chunk = new byte[val];\r
 553                     Read(chunk, 0, chunk.Length);\r
 554                     buf.Write(chunk, 0, chunk.Length);\r
 555                     ReadLine();\r
 556                 }\r
 557                 string line;\r
 558                 do\r
 559                 {\r
 560                     line = ReadLine();\r
 561                 } while (line != "" && line != "\r\n");\r
 562                 return buf.ToArray();\r
 563             }\r
 564 \r
 565             public byte[] ReadToEnd()\r
 566             {\r
 567                 var result = new MemoryStream();\r
 568                 var buf = new byte[4096];\r
 569                 int len;\r
 570                 while ((len = Read(buf, 0, buf.Length)) > 0)\r
 571                     result.Write(buf, 0, len);\r
 572                 return result.ToArray();\r
 573             }\r
 574 \r
 575             public HttpStream Write(byte[] body)\r
 576             {\r
 577                 if (body != null)\r
 578                     Write(body, 0, body.Length);\r
 579                 return this;\r
 580             }\r
 581 \r
 582             public int Read(byte[] buf, int offset, int count)\r
 583             {\r
 584                 var total = 0;\r
 585                 do\r
 586                 {\r
 587                     int n;\r
 588                     if (_position < _available)\r
 589                     {\r
 590                         n = Math.Min(count, _available - _position);\r
 591                         Buffer.BlockCopy(_buffer, _position, buf, 0, n);\r
 592                         _position += n;\r
 593                     }\r
 594                     else\r
 595                     {\r
 596                         n = _socket.Receive(buf, offset, count, SocketFlags.None);\r
 597                         if (n == 0)\r
 598                             return total == 0 ? n : total;\r
 599                     }\r
 600                     count -= n;\r
 601                     offset += n;\r
 602                     total += n;\r
 603                 } while (count > 0);\r
 604                 return total;\r
 605             }\r
 606 \r
 607             public void Write(byte[] buf, int offset, int count)\r
 608             {\r
 609                 do\r
 610                 {\r
 611                     var n = _socket.Send(buf, offset, count, SocketFlags.None);\r
 612                     if (n == 0)\r
 613                         return;\r
 614                     count -= n;\r
 615                     offset += n;\r
 616                 } while (count > 0);\r
 617             }\r
 618 \r
 619             public HttpStream Close()\r
 620             {\r
 621                 _socket.Close();\r
 622                 return this;\r
 623             }\r
 624         }\r
 625     }\r
 626 }