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