CMakeLua/Utilities/cmcurl-7.19.0/lib/content_encoding.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
   9  *
  10  * This software is licensed as described in the file COPYING, which
  11  * you should have received as part of this distribution. The terms
  12  * are also available at http://curl.haxx.se/docs/copyright.html.
  13  *
  14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15  * copies of the Software, and permit persons to whom the Software is
  16  * furnished to do so, under the terms of the COPYING file.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  * $Id: content_encoding.c,v 1.1.1.1 2008-09-23 16:32:05 hoffman Exp $
  22  ***************************************************************************/
  23
  24 #include "setup.h"
  25
  26 #ifdef HAVE_LIBZ
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #include "urldata.h"
  32 #include <curl/curl.h>
  33 #include "sendf.h"
  34 #include "content_encoding.h"
  35 #include "memory.h"
  36
  37 #include "memdebug.h"
  38
  39 /* Comment this out if zlib is always going to be at least ver. 1.2.0.4
  40    (doing so will reduce code size slightly). */
  41 #define OLD_ZLIB_SUPPORT 1
  42
  43 #define DSIZ 0x10000             /* buffer size for decompressed data */
  44
  45 #define GZIP_MAGIC_0 0x1f
  46 #define GZIP_MAGIC_1 0x8b
  47
  48 /* gzip flag byte */
  49 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
  50 #define HEAD_CRC     0x02 /* bit 1 set: header CRC present */
  51 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  52 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  53 #define COMMENT      0x10 /* bit 4 set: file comment present */
  54 #define RESERVED     0xE0 /* bits 5..7: reserved */
  55
  56 static CURLcode
  57 process_zlib_error(struct connectdata *conn, z_stream *z)
  58 {
  59   struct SessionHandle *data = conn->data;
  60   if(z->msg)
  61     failf (data, "Error while processing content unencoding: %s",
  62            z->msg);
  63   else
  64     failf (data, "Error while processing content unencoding: "
  65            "Unknown failure within decompression software.");
  66
  67   return CURLE_BAD_CONTENT_ENCODING;
  68 }
  69
  70 static CURLcode
  71 exit_zlib(z_stream *z, zlibInitState *zlib_init, CURLcode result)
  72 {
  73   inflateEnd(z);
  74   *zlib_init = ZLIB_UNINIT;
  75   return result;
  76 }
  77
  78 static CURLcode
  79 inflate_stream(struct connectdata *conn,
  80                struct SingleRequest *k)
  81 {
  82   int allow_restart = 1;
  83   z_stream *z = &k->z;          /* zlib state structure */
  84   uInt nread = z->avail_in;
  85   Bytef *orig_in = z->next_in;
  86   int status;                   /* zlib status */
  87   CURLcode result = CURLE_OK;   /* Curl_client_write status */
  88   char *decomp;                 /* Put the decompressed data here. */
  89
  90   /* Dynamically allocate a buffer for decompression because it's uncommonly
  91      large to hold on the stack */
  92   decomp = (char*)malloc(DSIZ);
  93   if(decomp == NULL) {
  94     return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
  95   }
  96
  97   /* because the buffer size is fixed, iteratively decompress and transfer to
  98      the client via client_write. */
  99   for (;;) {
 100     /* (re)set buffer for decompressed output for every iteration */
 101     z->next_out = (Bytef *)decomp;
 102     z->avail_out = DSIZ;
 103
 104     status = inflate(z, Z_SYNC_FLUSH);
 105     if(status == Z_OK || status == Z_STREAM_END) {
 106       allow_restart = 0;
 107       if(DSIZ - z->avail_out) {
 108         result = Curl_client_write(conn, CLIENTWRITE_BODY, decomp,
 109                                    DSIZ - z->avail_out);
 110         /* if !CURLE_OK, clean up, return */
 111         if(result) {
 112           free(decomp);
 113           return exit_zlib(z, &k->zlib_init, result);
 114         }
 115       }
 116
 117       /* Done? clean up, return */
 118       if(status == Z_STREAM_END) {
 119         free(decomp);
 120         if(inflateEnd(z) == Z_OK)
 121           return exit_zlib(z, &k->zlib_init, result);
 122         else
 123           return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 124       }
 125
 126       /* Done with these bytes, exit */
 127       if(status == Z_OK && z->avail_in == 0) {
 128         free(decomp);
 129         return result;
 130       }
 131     }
 132     else if(allow_restart && status == Z_DATA_ERROR) {
 133       /* some servers seem to not generate zlib headers, so this is an attempt
 134          to fix and continue anyway */
 135
 136       (void) inflateEnd(z);     /* don't care about the return code */
 137       if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
 138         return process_zlib_error(conn, z);
 139       }
 140       z->next_in = orig_in;
 141       z->avail_in = nread;
 142       allow_restart = 0;
 143       continue;
 144     }
 145     else {                      /* Error; exit loop, handle below */
 146       free(decomp);
 147       return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 148     }
 149   }
 150   /* Will never get here */
 151 }
 152
 153 CURLcode
 154 Curl_unencode_deflate_write(struct connectdata *conn,
 155                             struct SingleRequest *k,
 156                             ssize_t nread)
 157 {
 158   z_stream *z = &k->z;          /* zlib state structure */
 159
 160   /* Initialize zlib? */
 161   if(k->zlib_init == ZLIB_UNINIT) {
 162     z->zalloc = (alloc_func)Z_NULL;
 163     z->zfree = (free_func)Z_NULL;
 164     z->opaque = 0;
 165     z->next_in = NULL;
 166     z->avail_in = 0;
 167     if(inflateInit(z) != Z_OK)
 168       return process_zlib_error(conn, z);
 169     k->zlib_init = ZLIB_INIT;
 170   }
 171
 172   /* Set the compressed input when this function is called */
 173   z->next_in = (Bytef *)k->str;
 174   z->avail_in = (uInt)nread;
 175
 176   /* Now uncompress the data */
 177   return inflate_stream(conn, k);
 178 }
 179
 180 #ifdef OLD_ZLIB_SUPPORT
 181 /* Skip over the gzip header */
 182 static enum {
 183   GZIP_OK,
 184   GZIP_BAD,
 185   GZIP_UNDERFLOW
 186 } check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen)
 187 {
 188   int method, flags;
 189   const ssize_t totallen = len;
 190
 191   /* The shortest header is 10 bytes */
 192   if(len < 10)
 193     return GZIP_UNDERFLOW;
 194
 195   if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1))
 196     return GZIP_BAD;
 197
 198   method = data[2];
 199   flags = data[3];
 200
 201   if(method != Z_DEFLATED || (flags & RESERVED) != 0) {
 202     /* Can't handle this compression method or unknown flag */
 203     return GZIP_BAD;
 204   }
 205
 206   /* Skip over time, xflags, OS code and all previous bytes */
 207   len -= 10;
 208   data += 10;
 209
 210   if(flags & EXTRA_FIELD) {
 211     ssize_t extra_len;
 212
 213     if(len < 2)
 214       return GZIP_UNDERFLOW;
 215
 216     extra_len = (data[1] << 8) | data[0];
 217
 218     if(len < (extra_len+2))
 219       return GZIP_UNDERFLOW;
 220
 221     len -= (extra_len + 2);
 222     data += (extra_len + 2);
 223   }
 224
 225   if(flags & ORIG_NAME) {
 226     /* Skip over NUL-terminated file name */
 227     while(len && *data) {
 228       --len;
 229       ++data;
 230     }
 231     if(!len || *data)
 232       return GZIP_UNDERFLOW;
 233
 234     /* Skip over the NUL */
 235     --len;
 236     ++data;
 237   }
 238
 239   if(flags & COMMENT) {
 240     /* Skip over NUL-terminated comment */
 241     while(len && *data) {
 242       --len;
 243       ++data;
 244     }
 245     if(!len || *data)
 246       return GZIP_UNDERFLOW;
 247
 248     /* Skip over the NUL */
 249     --len;
 250     ++data;
 251   }
 252
 253   if(flags & HEAD_CRC) {
 254     if(len < 2)
 255       return GZIP_UNDERFLOW;
 256
 257     len -= 2;
 258     data += 2;
 259   }
 260
 261   *headerlen = totallen - len;
 262   return GZIP_OK;
 263 }
 264 #endif
 265
 266 CURLcode
 267 Curl_unencode_gzip_write(struct connectdata *conn,
 268                          struct SingleRequest *k,
 269                          ssize_t nread)
 270 {
 271   z_stream *z = &k->z;          /* zlib state structure */
 272
 273   /* Initialize zlib? */
 274   if(k->zlib_init == ZLIB_UNINIT) {
 275     z->zalloc = (alloc_func)Z_NULL;
 276     z->zfree = (free_func)Z_NULL;
 277     z->opaque = 0;
 278     z->next_in = NULL;
 279     z->avail_in = 0;
 280
 281     if(strcmp(zlibVersion(), "1.2.0.4") >= 0) {
 282         /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */
 283         if(inflateInit2(z, MAX_WBITS+32) != Z_OK) {
 284           return process_zlib_error(conn, z);
 285         }
 286         k->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */
 287
 288     } else {
 289         /* we must parse the gzip header ourselves */
 290         if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
 291           return process_zlib_error(conn, z);
 292         }
 293         k->zlib_init = ZLIB_INIT;   /* Initial call state */
 294     }
 295   }
 296
 297   if(k->zlib_init == ZLIB_INIT_GZIP) {
 298      /* Let zlib handle the gzip decompression entirely */
 299      z->next_in = (Bytef *)k->str;
 300      z->avail_in = (uInt)nread;
 301      /* Now uncompress the data */
 302      return inflate_stream(conn, k);
 303   }
 304
 305 #ifndef OLD_ZLIB_SUPPORT
 306   /* Support for old zlib versions is compiled away and we are running with
 307      an old version, so return an error. */
 308   return exit_zlib(z, &k->zlib_init, CURLE_FUNCTION_NOT_FOUND);
 309
 310 #else
 311   /* This next mess is to get around the potential case where there isn't
 312    * enough data passed in to skip over the gzip header.  If that happens, we
 313    * malloc a block and copy what we have then wait for the next call.  If
 314    * there still isn't enough (this is definitely a worst-case scenario), we
 315    * make the block bigger, copy the next part in and keep waiting.
 316    *
 317    * This is only required with zlib versions < 1.2.0.4 as newer versions
 318    * can handle the gzip header themselves.
 319    */
 320
 321   switch (k->zlib_init) {
 322   /* Skip over gzip header? */
 323   case ZLIB_INIT:
 324   {
 325     /* Initial call state */
 326     ssize_t hlen;
 327
 328     switch (check_gzip_header((unsigned char *)k->str, nread, &hlen)) {
 329     case GZIP_OK:
 330       z->next_in = (Bytef *)k->str + hlen;
 331       z->avail_in = (uInt)(nread - hlen);
 332       k->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
 333       break;
 334
 335     case GZIP_UNDERFLOW:
 336       /* We need more data so we can find the end of the gzip header.  It's
 337        * possible that the memory block we malloc here will never be freed if
 338        * the transfer abruptly aborts after this point.  Since it's unlikely
 339        * that circumstances will be right for this code path to be followed in
 340        * the first place, and it's even more unlikely for a transfer to fail
 341        * immediately afterwards, it should seldom be a problem.
 342        */
 343       z->avail_in = (uInt)nread;
 344       z->next_in = malloc(z->avail_in);
 345       if(z->next_in == NULL) {
 346         return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
 347       }
 348       memcpy(z->next_in, k->str, z->avail_in);
 349       k->zlib_init = ZLIB_GZIP_HEADER;   /* Need more gzip header data state */
 350       /* We don't have any data to inflate yet */
 351       return CURLE_OK;
 352
 353     case GZIP_BAD:
 354     default:
 355       return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 356     }
 357
 358   }
 359   break;
 360
 361   case ZLIB_GZIP_HEADER:
 362   {
 363     /* Need more gzip header data state */
 364     ssize_t hlen;
 365     unsigned char *oldblock = z->next_in;
 366
 367     z->avail_in += nread;
 368     z->next_in = realloc(z->next_in, z->avail_in);
 369     if(z->next_in == NULL) {
 370       free(oldblock);
 371       return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
 372     }
 373     /* Append the new block of data to the previous one */
 374     memcpy(z->next_in + z->avail_in - nread, k->str, nread);
 375
 376     switch (check_gzip_header(z->next_in, z->avail_in, &hlen)) {
 377     case GZIP_OK:
 378       /* This is the zlib stream data */
 379       free(z->next_in);
 380       /* Don't point into the malloced block since we just freed it */
 381       z->next_in = (Bytef *)k->str + hlen + nread - z->avail_in;
 382       z->avail_in = (uInt)(z->avail_in - hlen);
 383       k->zlib_init = ZLIB_GZIP_INFLATING;   /* Inflating stream state */
 384       break;
 385
 386     case GZIP_UNDERFLOW:
 387       /* We still don't have any data to inflate! */
 388       return CURLE_OK;
 389
 390     case GZIP_BAD:
 391     default:
 392       free(z->next_in);
 393       return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 394     }
 395
 396   }
 397   break;
 398
 399   case ZLIB_GZIP_INFLATING:
 400   default:
 401     /* Inflating stream state */
 402     z->next_in = (Bytef *)k->str;
 403     z->avail_in = (uInt)nread;
 404     break;
 405   }
 406
 407   if(z->avail_in == 0) {
 408     /* We don't have any data to inflate; wait until next time */
 409     return CURLE_OK;
 410   }
 411
 412   /* We've parsed the header, now uncompress the data */
 413   return inflate_stream(conn, k);
 414 #endif
 415 }
 416 #endif /* HAVE_LIBZ */