mcs/class/System/System.Net/ChunkStream.cs

   1 //
   2 // System.Net.ChunkStream
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2003 Ximian, Inc (http://www.ximian.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Collections;
  32 using System.Collections.Generic;
  33 using System.Globalization;
  34 using System.IO;
  35 using System.Text;
  36
  37 namespace System.Net
  38 {
  39         class ChunkStream
  40         {
  41                 enum State {
  42                         None,
  43                         PartialSize,
  44                         Body,
  45                         BodyFinished,
  46                         Trailer
  47                 }
  48
  49                 class Chunk {
  50                         public byte [] Bytes;
  51                         public int Offset;
  52
  53                         public Chunk (byte [] chunk)
  54                         {
  55                                 this.Bytes = chunk;
  56                         }
  57
  58                         public int Read (byte [] buffer, int offset, int size)
  59                         {
  60                                 int nread = (size > Bytes.Length - Offset) ? Bytes.Length - Offset : size;
  61                                 Buffer.BlockCopy (Bytes, Offset, buffer, offset, nread);
  62                                 Offset += nread;
  63                                 return nread;
  64                         }
  65                 }
  66
  67                 internal WebHeaderCollection headers;
  68                 int chunkSize;
  69                 int chunkRead;
  70                 int totalWritten;
  71                 State state;
  72                 //byte [] waitBuffer;
  73                 StringBuilder saved;
  74                 bool sawCR;
  75                 bool gotit;
  76                 int trailerState;
  77                 ArrayList chunks;
  78
  79                 public ChunkStream (byte [] buffer, int offset, int size, WebHeaderCollection headers)
  80                                         : this (headers)
  81                 {
  82                         Write (buffer, offset, size);
  83                 }
  84
  85                 public ChunkStream (WebHeaderCollection headers)
  86                 {
  87                         this.headers = headers;
  88                         saved = new StringBuilder ();
  89                         chunks = new ArrayList ();
  90                         chunkSize = -1;
  91                         totalWritten = 0;
  92                 }
  93
  94                 public void ResetBuffer ()
  95                 {
  96                         chunkSize = -1;
  97                         chunkRead = 0;
  98                         totalWritten = 0;
  99                         chunks.Clear ();
 100                 }
 101
 102                 public void WriteAndReadBack (byte [] buffer, int offset, int size, ref int read)
 103                 {
 104                         if (offset + read > 0)
 105                                 Write (buffer, offset, offset+read);
 106                         read = Read (buffer, offset, size);
 107                 }
 108
 109                 public int Read (byte [] buffer, int offset, int size)
 110                 {
 111                         return ReadFromChunks (buffer, offset, size);
 112                 }
 113
 114                 int ReadFromChunks (byte [] buffer, int offset, int size)
 115                 {
 116                         int count = chunks.Count;
 117                         int nread = 0;
 118
 119                         var chunksForRemoving = new List<Chunk>(count);
 120                         for (int i = 0; i < count; i++) {
 121                                 Chunk chunk = (Chunk) chunks [i];
 122
 123                                 if (chunk.Offset == chunk.Bytes.Length) {
 124                                         chunksForRemoving.Add(chunk);
 125                                         continue;
 126                                 }
 127
 128                                 nread += chunk.Read (buffer, offset + nread, size - nread);
 129                                 if (nread == size)
 130                                         break;
 131                         }
 132
 133                         foreach (var chunk in chunksForRemoving)
 134                                 chunks.Remove(chunk);
 135
 136                         return nread;
 137                 }
 138
 139                 public void Write (byte [] buffer, int offset, int size)
 140                 {
 141                         if (offset < size)
 142                                 InternalWrite (buffer, ref offset, size);
 143                 }
 144
 145                 void InternalWrite (byte [] buffer, ref int offset, int size)
 146                 {
 147                         if (state == State.None || state == State.PartialSize) {
 148                                 state = GetChunkSize (buffer, ref offset, size);
 149                                 if (state == State.PartialSize)
 150                                         return;
 151
 152                                 saved.Length = 0;
 153                                 sawCR = false;
 154                                 gotit = false;
 155                         }
 156
 157                         if (state == State.Body && offset < size) {
 158                                 state = ReadBody (buffer, ref offset, size);
 159                                 if (state == State.Body)
 160                                         return;
 161                         }
 162
 163                         if (state == State.BodyFinished && offset < size) {
 164                                 state = ReadCRLF (buffer, ref offset, size);
 165                                 if (state == State.BodyFinished)
 166                                         return;
 167
 168                                 sawCR = false;
 169                         }
 170
 171                         if (state == State.Trailer && offset < size) {
 172                                 state = ReadTrailer (buffer, ref offset, size);
 173                                 if (state == State.Trailer)
 174                                         return;
 175
 176                                 saved.Length = 0;
 177                                 sawCR = false;
 178                                 gotit = false;
 179                         }
 180
 181                         if (offset < size)
 182                                 InternalWrite (buffer, ref offset, size);
 183                 }
 184
 185                 public bool WantMore {
 186                         get { return (chunkRead != chunkSize || chunkSize != 0 || state != State.None); }
 187                 }
 188
 189                 public bool DataAvailable {
 190                         get {
 191                                 int count = chunks.Count;
 192                                 for (int i = 0; i < count; i++) {
 193                                         Chunk ch = (Chunk) chunks [i];
 194                                         if (ch == null || ch.Bytes == null)
 195                                                 continue;
 196                                         if (ch.Bytes.Length > 0 && ch.Offset < ch.Bytes.Length)
 197                                                 return (state != State.Body);
 198                                 }
 199                                 return false;
 200                         }
 201                 }
 202
 203                 public int TotalDataSize {
 204                         get { return totalWritten; }
 205                 }
 206
 207                 public int ChunkLeft {
 208                         get { return chunkSize - chunkRead; }
 209                 }
 210
 211                 State ReadBody (byte [] buffer, ref int offset, int size)
 212                 {
 213                         if (chunkSize == 0)
 214                                 return State.BodyFinished;
 215
 216                         int diff = size - offset;
 217                         if (diff + chunkRead > chunkSize)
 218                                 diff = chunkSize - chunkRead;
 219
 220                         byte [] chunk = new byte [diff];
 221                         Buffer.BlockCopy (buffer, offset, chunk, 0, diff);
 222                         chunks.Add (new Chunk (chunk));
 223                         offset += diff;
 224                         chunkRead += diff;
 225                         totalWritten += diff;
 226                         return (chunkRead == chunkSize) ? State.BodyFinished : State.Body;
 227
 228                 }
 229
 230                 State GetChunkSize (byte [] buffer, ref int offset, int size)
 231                 {
 232                         chunkRead = 0;
 233                         chunkSize = 0;
 234                         char c = '\0';
 235                         while (offset < size) {
 236                                 c = (char) buffer [offset++];
 237                                 if (c == '\r') {
 238                                         if (sawCR)
 239                                                 ThrowProtocolViolation ("2 CR found");
 240
 241                                         sawCR = true;
 242                                         continue;
 243                                 }
 244
 245                                 if (sawCR && c == '\n')
 246                                         break;
 247
 248                                 if (c == ' ')
 249                                         gotit = true;
 250
 251                                 if (!gotit)
 252                                         saved.Append (c);
 253
 254                                 if (saved.Length > 20)
 255                                         ThrowProtocolViolation ("chunk size too long.");
 256                         }
 257
 258                         if (!sawCR || c != '\n') {
 259                                 if (offset < size)
 260                                         ThrowProtocolViolation ("Missing \\n");
 261
 262                                 try {
 263                                         if (saved.Length > 0) {
 264                                                 chunkSize = Int32.Parse (RemoveChunkExtension (saved.ToString ()), NumberStyles.HexNumber);
 265                                         }
 266                                 } catch (Exception) {
 267                                         ThrowProtocolViolation ("Cannot parse chunk size.");
 268                                 }
 269
 270                                 return State.PartialSize;
 271                         }
 272
 273                         chunkRead = 0;
 274                         try {
 275                                 chunkSize = Int32.Parse (RemoveChunkExtension (saved.ToString ()), NumberStyles.HexNumber);
 276                         } catch (Exception) {
 277                                 ThrowProtocolViolation ("Cannot parse chunk size.");
 278                         }
 279
 280                         if (chunkSize == 0) {
 281                                 trailerState = 2;
 282                                 return State.Trailer;
 283                         }
 284
 285                         return State.Body;
 286                 }
 287
 288                 static string RemoveChunkExtension (string input)
 289                 {
 290                         int idx = input.IndexOf (';');
 291                         if (idx == -1)
 292                                 return input;
 293                         return input.Substring (0, idx);
 294                 }
 295
 296                 State ReadCRLF (byte [] buffer, ref int offset, int size)
 297                 {
 298                         if (!sawCR) {
 299                                 if ((char) buffer [offset++] != '\r')
 300                                         ThrowProtocolViolation ("Expecting \\r");
 301
 302                                 sawCR = true;
 303                                 if (offset == size)
 304                                         return State.BodyFinished;
 305                         }
 306
 307                         if (sawCR && (char) buffer [offset++] != '\n')
 308                                 ThrowProtocolViolation ("Expecting \\n");
 309
 310                         return State.None;
 311                 }
 312
 313                 State ReadTrailer (byte [] buffer, ref int offset, int size)
 314                 {
 315                         char c = '\0';
 316
 317                         // short path
 318                         if (trailerState == 2 && (char) buffer [offset] == '\r' && saved.Length == 0) {
 319                                 offset++;
 320                                 if (offset < size && (char) buffer [offset] == '\n') {
 321                                         offset++;
 322                                         return State.None;
 323                                 }
 324                                 offset--;
 325                         }
 326
 327                         int st = trailerState;
 328                         string stString = "\r\n\r";
 329                         while (offset < size && st < 4) {
 330                                 c = (char) buffer [offset++];
 331                                 if ((st == 0 || st == 2) && c == '\r') {
 332                                         st++;
 333                                         continue;
 334                                 }
 335
 336                                 if ((st == 1 || st == 3) && c == '\n') {
 337                                         st++;
 338                                         continue;
 339                                 }
 340
 341                                 if (st > 0) {
 342                                         saved.Append (stString.Substring (0, saved.Length == 0? st-2: st));
 343                                         st = 0;
 344                                         if (saved.Length > 4196)
 345                                                 ThrowProtocolViolation ("Error reading trailer (too long).");
 346                                 }
 347                         }
 348
 349                         if (st < 4) {
 350                                 trailerState = st;
 351                                 if (offset < size)
 352                                         ThrowProtocolViolation ("Error reading trailer.");
 353
 354                                 return State.Trailer;
 355                         }
 356
 357                         StringReader reader = new StringReader (saved.ToString ());
 358                         string line;
 359                         while ((line = reader.ReadLine ()) != null && line != "")
 360                                 headers.Add (line);
 361
 362                         return State.None;
 363                 }
 364
 365                 static void ThrowProtocolViolation (string message)
 366                 {
 367                         WebException we = new WebException (message, null, WebExceptionStatus.ServerProtocolViolation, null);
 368                         throw we;
 369                 }
 370         }
 371 }
 372