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.Globalization;
  33 using System.IO;
  34 using System.Text;
  35
  36 namespace System.Net
  37 {
  38         class ChunkStream
  39         {
  40                 enum State {
  41                         None,
  42                         PartialSize,
  43                         Body,
  44                         BodyFinished,
  45                         Trailer
  46                 }
  47
  48                 class Chunk {
  49                         public byte [] Bytes;
  50                         public int Offset;
  51
  52                         public Chunk (byte [] chunk)
  53                         {
  54                                 this.Bytes = chunk;
  55                         }
  56
  57                         public int Read (byte [] buffer, int offset, int size)
  58                         {
  59                                 int nread = (size > Bytes.Length - Offset) ? Bytes.Length - Offset : size;
  60                                 Buffer.BlockCopy (Bytes, Offset, buffer, offset, nread);
  61                                 Offset += nread;
  62                                 return nread;
  63                         }
  64                 }
  65
  66                 internal WebHeaderCollection headers;
  67                 int chunkSize;
  68                 int chunkRead;
  69                 int totalWritten;
  70                 State state;
  71                 //byte [] waitBuffer;
  72                 StringBuilder saved;
  73                 bool sawCR;
  74                 bool gotit;
  75                 int trailerState;
  76                 ArrayList chunks;
  77
  78                 public ChunkStream (byte [] buffer, int offset, int size, WebHeaderCollection headers)
  79                                         : this (headers)
  80                 {
  81                         Write (buffer, offset, size);
  82                 }
  83
  84                 public ChunkStream (WebHeaderCollection headers)
  85                 {
  86                         this.headers = headers;
  87                         saved = new StringBuilder ();
  88                         chunks = new ArrayList ();
  89                         chunkSize = -1;
  90                         totalWritten = 0;
  91                 }
  92
  93                 public void ResetBuffer ()
  94                 {
  95                         chunkSize = -1;
  96                         chunkRead = 0;
  97                         totalWritten = 0;
  98                         chunks.Clear ();
  99                 }
 100
 101                 public void WriteAndReadBack (byte [] buffer, int offset, int size, ref int read)
 102                 {
 103                         if (offset + read > 0)
 104                                 Write (buffer, offset, offset+read);
 105                         read = Read (buffer, offset, size);
 106                 }
 107
 108                 public int Read (byte [] buffer, int offset, int size)
 109                 {
 110                         return ReadFromChunks (buffer, offset, size);
 111                 }
 112
 113                 int ReadFromChunks (byte [] buffer, int offset, int size)
 114                 {
 115                         int count = chunks.Count;
 116                         int nread = 0;
 117                         for (int i = 0; i < count; i++) {
 118                                 Chunk chunk = (Chunk) chunks [i];
 119                                 if (chunk == null)
 120                                         continue;
 121
 122                                 if (chunk.Offset == chunk.Bytes.Length) {
 123                                         chunks [i] = null;
 124                                         continue;
 125                                 }
 126
 127                                 nread += chunk.Read (buffer, offset + nread, size - nread);
 128                                 if (nread == size)
 129                                         break;
 130                         }
 131
 132                         return nread;
 133                 }
 134
 135                 public void Write (byte [] buffer, int offset, int size)
 136                 {
 137                         if (offset < size)
 138                                 InternalWrite (buffer, ref offset, size);
 139                 }
 140
 141                 void InternalWrite (byte [] buffer, ref int offset, int size)
 142                 {
 143                         if (state == State.None || state == State.PartialSize) {
 144                                 state = GetChunkSize (buffer, ref offset, size);
 145                                 if (state == State.PartialSize)
 146                                         return;
 147
 148                                 saved.Length = 0;
 149                                 sawCR = false;
 150                                 gotit = false;
 151                         }
 152
 153                         if (state == State.Body && offset < size) {
 154                                 state = ReadBody (buffer, ref offset, size);
 155                                 if (state == State.Body)
 156                                         return;
 157                         }
 158
 159                         if (state == State.BodyFinished && offset < size) {
 160                                 state = ReadCRLF (buffer, ref offset, size);
 161                                 if (state == State.BodyFinished)
 162                                         return;
 163
 164                                 sawCR = false;
 165                         }
 166
 167                         if (state == State.Trailer && offset < size) {
 168                                 state = ReadTrailer (buffer, ref offset, size);
 169                                 if (state == State.Trailer)
 170                                         return;
 171
 172                                 saved.Length = 0;
 173                                 sawCR = false;
 174                                 gotit = false;
 175                         }
 176
 177                         if (offset < size)
 178                                 InternalWrite (buffer, ref offset, size);
 179                 }
 180
 181                 public bool WantMore {
 182                         get { return (chunkRead != chunkSize || chunkSize != 0 || state != State.None); }
 183                 }
 184
 185                 public bool DataAvailable {
 186                         get {
 187                                 int count = chunks.Count;
 188                                 for (int i = 0; i < count; i++) {
 189                                         Chunk ch = (Chunk) chunks [i];
 190                                         if (ch == null || ch.Bytes == null)
 191                                                 continue;
 192                                         if (ch.Bytes.Length > 0 && ch.Offset < ch.Bytes.Length)
 193                                                 return (state != State.Body);
 194                                 }
 195                                 return false;
 196                         }
 197                 }
 198
 199                 public int TotalDataSize {
 200                         get { return totalWritten; }
 201                 }
 202
 203                 public int ChunkLeft {
 204                         get { return chunkSize - chunkRead; }
 205                 }
 206
 207                 State ReadBody (byte [] buffer, ref int offset, int size)
 208                 {
 209                         if (chunkSize == 0)
 210                                 return State.BodyFinished;
 211
 212                         int diff = size - offset;
 213                         if (diff + chunkRead > chunkSize)
 214                                 diff = chunkSize - chunkRead;
 215
 216                         byte [] chunk = new byte [diff];
 217                         Buffer.BlockCopy (buffer, offset, chunk, 0, diff);
 218                         chunks.Add (new Chunk (chunk));
 219                         offset += diff;
 220                         chunkRead += diff;
 221                         totalWritten += diff;
 222                         return (chunkRead == chunkSize) ? State.BodyFinished : State.Body;
 223
 224                 }
 225
 226                 State GetChunkSize (byte [] buffer, ref int offset, int size)
 227                 {
 228                         chunkRead = 0;
 229                         chunkSize = 0;
 230                         char c = '\0';
 231                         while (offset < size) {
 232                                 c = (char) buffer [offset++];
 233                                 if (c == '\r') {
 234                                         if (sawCR)
 235                                                 ThrowProtocolViolation ("2 CR found");
 236
 237                                         sawCR = true;
 238                                         continue;
 239                                 }
 240
 241                                 if (sawCR && c == '\n')
 242                                         break;
 243
 244                                 if (c == ' ')
 245                                         gotit = true;
 246
 247                                 if (!gotit)
 248                                         saved.Append (c);
 249
 250                                 if (saved.Length > 20)
 251                                         ThrowProtocolViolation ("chunk size too long.");
 252                         }
 253
 254                         if (!sawCR || c != '\n') {
 255                                 if (offset < size)
 256                                         ThrowProtocolViolation ("Missing \\n");
 257
 258                                 try {
 259                                         if (saved.Length > 0) {
 260                                                 chunkSize = Int32.Parse (RemoveChunkExtension (saved.ToString ()), NumberStyles.HexNumber);
 261                                         }
 262                                 } catch (Exception) {
 263                                         ThrowProtocolViolation ("Cannot parse chunk size.");
 264                                 }
 265
 266                                 return State.PartialSize;
 267                         }
 268
 269                         chunkRead = 0;
 270                         try {
 271                                 chunkSize = Int32.Parse (RemoveChunkExtension (saved.ToString ()), NumberStyles.HexNumber);
 272                         } catch (Exception) {
 273                                 ThrowProtocolViolation ("Cannot parse chunk size.");
 274                         }
 275
 276                         if (chunkSize == 0) {
 277                                 trailerState = 2;
 278                                 return State.Trailer;
 279                         }
 280
 281                         return State.Body;
 282                 }
 283
 284                 static string RemoveChunkExtension (string input)
 285                 {
 286                         int idx = input.IndexOf (';');
 287                         if (idx == -1)
 288                                 return input;
 289                         return input.Substring (0, idx);
 290                 }
 291
 292                 State ReadCRLF (byte [] buffer, ref int offset, int size)
 293                 {
 294                         if (!sawCR) {
 295                                 if ((char) buffer [offset++] != '\r')
 296                                         ThrowProtocolViolation ("Expecting \\r");
 297
 298                                 sawCR = true;
 299                                 if (offset == size)
 300                                         return State.BodyFinished;
 301                         }
 302
 303                         if (sawCR && (char) buffer [offset++] != '\n')
 304                                 ThrowProtocolViolation ("Expecting \\n");
 305
 306                         return State.None;
 307                 }
 308
 309                 State ReadTrailer (byte [] buffer, ref int offset, int size)
 310                 {
 311                         char c = '\0';
 312
 313                         // short path
 314                         if (trailerState == 2 && (char) buffer [offset] == '\r' && saved.Length == 0) {
 315                                 offset++;
 316                                 if (offset < size && (char) buffer [offset] == '\n') {
 317                                         offset++;
 318                                         return State.None;
 319                                 }
 320                                 offset--;
 321                         }
 322
 323                         int st = trailerState;
 324                         string stString = "\r\n\r";
 325                         while (offset < size && st < 4) {
 326                                 c = (char) buffer [offset++];
 327                                 if ((st == 0 || st == 2) && c == '\r') {
 328                                         st++;
 329                                         continue;
 330                                 }
 331
 332                                 if ((st == 1 || st == 3) && c == '\n') {
 333                                         st++;
 334                                         continue;
 335                                 }
 336
 337                                 if (st > 0) {
 338                                         saved.Append (stString.Substring (0, saved.Length == 0? st-2: st));
 339                                         st = 0;
 340                                         if (saved.Length > 4196)
 341                                                 ThrowProtocolViolation ("Error reading trailer (too long).");
 342                                 }
 343                         }
 344
 345                         if (st < 4) {
 346                                 trailerState = st;
 347                                 if (offset < size)
 348                                         ThrowProtocolViolation ("Error reading trailer.");
 349
 350                                 return State.Trailer;
 351                         }
 352
 353                         StringReader reader = new StringReader (saved.ToString ());
 354                         string line;
 355                         while ((line = reader.ReadLine ()) != null && line != "")
 356                                 headers.Add (line);
 357
 358                         return State.None;
 359                 }
 360
 361                 static void ThrowProtocolViolation (string message)
 362                 {
 363                         WebException we = new WebException (message, null, WebExceptionStatus.ServerProtocolViolation, null);
 364                         throw we;
 365                 }
 366         }
 367 }
 368