kio/httpfilter/httpfilter.cc

   1 /*
   2    This file is part of the KDE libraries
   3    Copyright (c) 2002 Waldo Bastian <bastian@kde.org>
   4
   5    This library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public
   7    License version 2 as published by the Free Software Foundation.
   8
   9    This library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public License
  15    along with this library; see the file COPYING.LIB.  If not, write to
  16    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17    Boston, MA 02110-1301, USA.
  18 */
  19
  20 #include "httpfilter.h"
  21
  22 #include <kio/global.h>
  23
  24 #include <klocale.h>
  25
  26 #include <stdio.h>
  27
  28 HTTPFilterBase::HTTPFilterBase()
  29  : last(0)
  30 {
  31 }
  32
  33 HTTPFilterBase::~HTTPFilterBase()
  34 {
  35    delete last;
  36 }
  37
  38 void
  39 HTTPFilterBase::chain(HTTPFilterBase *previous)
  40 {
  41    last = previous;
  42    connect(last, SIGNAL(output(const QByteArray &)),
  43            this, SLOT(slotInput(const QByteArray &)));
  44 }
  45
  46 HTTPFilterChain::HTTPFilterChain()
  47  : first(0)
  48 {
  49 }
  50
  51 void
  52 HTTPFilterChain::addFilter(HTTPFilterBase *filter)
  53 {
  54    if (!last)
  55    {
  56       first = filter;
  57    }
  58    else
  59    {
  60       disconnect(last, SIGNAL(output(const QByteArray &)), 0, 0);
  61       filter->chain(last);
  62    }
  63    last = filter;
  64    connect(filter, SIGNAL(output(const QByteArray &)),
  65            this, SIGNAL(output(const QByteArray &)));
  66    connect(filter, SIGNAL(error(int, const QString &)),
  67            this, SIGNAL(error(int, const QString &)));
  68 }
  69
  70 void
  71 HTTPFilterChain::slotInput(const QByteArray &d)
  72 {
  73    if (first)
  74       first->slotInput(d);
  75    else
  76       emit output(d);
  77 }
  78
  79 HTTPFilterMD5::HTTPFilterMD5()
  80 {
  81 }
  82
  83 QString
  84 HTTPFilterMD5::md5()
  85 {
  86    return QLatin1String(context.base64Digest());
  87 }
  88
  89 void
  90 HTTPFilterMD5::slotInput(const QByteArray &d)
  91 {
  92    context.update(d);
  93    emit output(d);
  94 }
  95
  96
  97 HTTPFilterGZip::HTTPFilterGZip()
  98 {
  99 #ifdef DO_GZIP
 100   bHasHeader = false;
 101   bHasFinished = false;
 102   bPlainText = false;
 103   bEatTrailer = false;
 104   bEof = false;
 105   zstr.next_in = (Bytef *) Z_NULL;
 106   zstr.avail_in = 0;
 107   zstr.zalloc = Z_NULL;
 108   zstr.zfree = Z_NULL;
 109   zstr.opaque = Z_NULL;
 110   inflateInit2(&zstr, -MAX_WBITS);
 111   iTrailer = 8;
 112 #endif
 113 }
 114
 115 HTTPFilterGZip::~HTTPFilterGZip()
 116 {
 117 #ifdef DO_GZIP
 118   inflateEnd(&zstr);
 119 #endif
 120
 121 }
 122
 123 /* The get_byte() and checkHeader() functions are modified version from */
 124 /* the correpsonding functions that can be found in zlib, the following */
 125 /* copyright notice applies to these functions:                         */
 126
 127 /* zlib.h -- interface of the 'zlib' general purpose compression library
 128   version 1.1.3, July 9th, 1998
 129
 130   Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
 131
 132   This software is provided 'as-is', without any express or implied
 133   warranty.  In no event will the authors be held liable for any damages
 134   arising from the use of this software.
 135
 136   Permission is granted to anyone to use this software for any purpose,
 137   including commercial applications, and to alter it and redistribute it
 138   freely, subject to the following restrictions:
 139
 140   1. The origin of this software must not be misrepresented; you must not
 141      claim that you wrote the original software. If you use this software
 142      in a product, an acknowledgment in the product documentation would be
 143      appreciated but is not required.
 144   2. Altered source versions must be plainly marked as such, and must not be
 145      misrepresented as being the original software.
 146   3. This notice may not be removed or altered from any source distribution.
 147
 148   Jean-loup Gailly        Mark Adler
 149   jloup@gzip.org          madler@alumni.caltech.edu
 150
 151
 152   The data format used by the zlib library is described by RFCs (Request for
 153   Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
 154   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
 155 */
 156
 157 int
 158 HTTPFilterGZip::get_byte()
 159 {
 160 #ifdef DO_GZIP
 161     if (bEof) return EOF;
 162     if (zstr.avail_in == 0)
 163     {
 164         bEof = true;
 165         return EOF;
 166     }
 167     zstr.avail_in--;
 168     zstr.total_in++;
 169     return *(zstr.next_in)++;
 170 #else
 171     return 0;
 172 #endif
 173 }
 174
 175 #ifdef DO_GZIP
 176
 177 static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
 178
 179 /* gzip flag byte */
 180 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
 181 #define HEAD_CRC     0x02 /* bit 1 set: header CRC present */
 182 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 183 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 184 #define COMMENT      0x10 /* bit 4 set: file comment present */
 185 #define RESERVED     0xE0 /* bits 5..7: reserved */
 186 #endif
 187
 188 // 0 : ok
 189 // 1 : not gzip
 190 // 2 : no header
 191 int
 192 HTTPFilterGZip::checkHeader()
 193 {
 194 #ifdef DO_GZIP
 195     uInt len;
 196     int c;
 197
 198     /* Check the gzip magic header */
 199     for (len = 0; len < 2; ++len) {
 200         c = get_byte();
 201         if (c != gz_magic[len]) {
 202             if (len != 0)
 203             {
 204                zstr.avail_in++;
 205                zstr.next_in--;
 206             }
 207             if (c != EOF) {
 208                 zstr.avail_in++;
 209                 zstr.next_in--;
 210                 return 1;
 211             }
 212             return 2;
 213         }
 214     }
 215     int method = get_byte(); /* method byte */
 216     int flags = get_byte(); /* flags byte */
 217
 218     if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
 219         return bEof ? 2 : 1;
 220     }
 221
 222     /* Discard time, xflags and OS code: */
 223     for (len = 0; len < 6; ++len) (void)get_byte();
 224
 225     if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
 226         len  =  (uInt)get_byte();
 227         len += ((uInt)get_byte())<<8;
 228         /* len is garbage if EOF but the loop below will quit anyway */
 229         while (len-- != 0 && get_byte() != EOF) ;
 230     }
 231     if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
 232         while ((c = get_byte()) != 0 && c != EOF) ;
 233     }
 234     if ((flags & COMMENT) != 0) {   /* skip the .gz file comment */
 235         while ((c = get_byte()) != 0 && c != EOF) ;
 236     }
 237     if ((flags & HEAD_CRC) != 0) {  /* skip the header crc */
 238         for (len = 0; len < 2; ++len) (void)get_byte();
 239     }
 240
 241     return bEof ? 2 : 0;
 242 #else
 243     return 0;
 244 #endif
 245 }
 246
 247 void
 248 HTTPFilterGZip::slotInput(const QByteArray &d)
 249 {
 250 #ifdef DO_GZIP
 251   if (bPlainText)
 252   {
 253      emit output(d);
 254      return;
 255   }
 256   if (d.size() == 0)
 257   {
 258      if (bEatTrailer)
 259         bHasFinished = true;
 260      if (!bHasFinished)
 261      {
 262         // Make sure we get the last bytes still in the pipe.
 263         // Needed with "deflate".
 264         QByteArray flush(4, 0);
 265         slotInput(flush);
 266         if (!bHasFinished && !bHasHeader)
 267         {
 268            // Send as-is
 269            emit output(headerData);
 270            bHasFinished = true;
 271            // End of data
 272            emit output(QByteArray());
 273         }
 274      }
 275      if (!bHasFinished)
 276         emit error( KIO::ERR_SLAVE_DEFINED, i18n("Unexpected end of data, some information may be lost."));
 277      return;
 278   }
 279   if (bHasFinished)
 280      return;
 281
 282   if (bEatTrailer)
 283   {
 284      iTrailer -= d.size();
 285      if (iTrailer <= 0)
 286      {
 287         bHasFinished = true;
 288         // End of data
 289         emit output(QByteArray());
 290      }
 291      return;
 292   }
 293
 294   if (!bHasHeader)
 295   {
 296      bEof = false;
 297
 298      // Add data to header.
 299      int orig_size = headerData.size();
 300      headerData.resize(orig_size+d.size());
 301      memcpy(headerData.data()+orig_size, d.data(), d.size());
 302
 303      zstr.avail_in = headerData.size();
 304      zstr.next_in = (Bytef *) headerData.data();
 305
 306      int result = checkHeader();
 307      if (result == 1)
 308      {
 309         bPlainText = true;
 310         output(headerData);
 311         return;
 312      }
 313
 314      if (result != 0)
 315         return; // next time better
 316
 317      bHasHeader = true;
 318   }
 319   else
 320   {
 321      zstr.avail_in = d.size();
 322      zstr.next_in = (Bytef *) d.data();
 323   }
 324
 325   while( zstr.avail_in )
 326   {
 327      char buf[8192];
 328      zstr.next_out = (Bytef *) buf;
 329      zstr.avail_out = 8192;
 330      int result = inflate( &zstr, Z_NO_FLUSH );
 331      if ((result != Z_OK) && (result != Z_STREAM_END))
 332      {
 333         emit error( KIO::ERR_SLAVE_DEFINED, i18n("Receiving corrupt data."));
 334         break;
 335      }
 336      int bytesOut = 8192 - zstr.avail_out;
 337      if (bytesOut)
 338      {
 339         QByteArray d( buf, bytesOut );
 340         emit output(d);
 341      }
 342      if (result == Z_STREAM_END)
 343      {
 344         if (iTrailer)
 345         {
 346            bEatTrailer = true;
 347         }
 348         else
 349         {
 350            bHasFinished = true;
 351            // End of data
 352            emit output(QByteArray());
 353         }
 354         return;
 355      }
 356   }
 357 #endif
 358 }
 359
 360 HTTPFilterDeflate::HTTPFilterDeflate()
 361 {
 362 #ifdef DO_GZIP
 363   bHasHeader = true;
 364   iTrailer = 0;
 365 #endif
 366 }
 367
 368 #include "httpfilter.moc"